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Sample records for inverse incidente relativiste

  1. The relativistic inverse stellar structure problem

    SciTech Connect

    Lindblom, Lee

    2014-01-14

    The observable macroscopic properties of relativistic stars (whose equations of state are known) can be predicted by solving the stellar structure equations that follow from Einstein’s equation. For neutron stars, however, our knowledge of the equation of state is poor, so the direct stellar structure problem can not be solved without modeling the highest density part of the equation of state in some way. This talk will describe recent work on developing a model independent approach to determining the high-density neutron-star equation of state by solving an inverse stellar structure problem. This method uses the fact that Einstein’s equation provides a deterministic relationship between the equation of state and the macroscopic observables of the stars which are composed of that material. This talk illustrates how this method will be able to determine the high-density part of the neutron-star equation of state with few percent accuracy when high quality measurements of the masses and radii of just two or three neutron stars become available. This talk will also show that this method can be used with measurements of other macroscopic observables, like the masses and tidal deformabilities, which can (in principle) be measured by gravitational wave observations of binary neutron-star mergers.

  2. INVERSE CASCADE OF NONHELICAL MAGNETIC TURBULENCE IN A RELATIVISTIC FLUID

    SciTech Connect

    Zrake, Jonathan

    2014-10-20

    The free decay of nonhelical relativistic magnetohydrodynamic turbulence is studied numerically, and found to exhibit cascading of magnetic energy toward large scales. Evolution of the magnetic energy spectrum P{sub M} (k, t) is self-similar in time and well modeled by a broken power law with subinertial and inertial range indices very close to 7/2 and –2, respectively. The magnetic coherence scale is found to grow in time as t {sup 2/5}, much too slow to account for optical polarization of gamma-ray burst afterglow emission if magnetic energy is to be supplied only at microphysical length scales. No bursty or explosive energy loss is observed in relativistic MHD turbulence having modest magnetization, which constrains magnetic reconnection models for rapid time variability of GRB prompt emission, blazars, and the Crab nebula.

  3. Inversion of Source and Transport Parameters of Relativistic SEPs from Neutron Monitor Data

    NASA Astrophysics Data System (ADS)

    Agueda, Neus; Bütikofer, Rolf; Vainio, Rami; Heber, Bernd; Afanasiev, Alexander; Malandraki, Olga E.

    2016-04-01

    We present a new methodology to study the release processes of relativistic solar energetic particles (SEPs) based on the direct inversion of Ground Level Enhancements (GLEs) observed by the worldwide network of neutron monitors (NMs). The new approach makes use of several models, including: the propagation of relativistic SEPs from the Sun to the Earth, their transport in the Earth's magnetosphere and atmosphere, as well as the detection of the nucleon component of the secondary cosmic rays by ground based NMs. The combination of these models allows us to compute the expected ground-level NM counting rates for a series of instantaneous releases from the Sun. The amplitudes of the source components are then inferred by fitting the NM observations with the modeled NM counting rate increases. Within the HESPERIA project, we will develop the first software package for the direct inversion of GLEs and we will make it freely available for the solar and heliospheric communities. Acknowledgement: This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324.

  4. Angular spectrum characteristics of relativistic inverse compton harmonic X-rays

    SciTech Connect

    Sakai, Y.; Xiao, L.; Barber, S.; O'Shea, F. H.; Williams, O.; Rosenzweig, J. B.; Pogorelsky, I.; Korostyshevsky, A.; Malone, B.; Kusche, K.; Montemagno, M.; Polyanskiy, M. N.; Babzien, M.; Fedurin, M.; Yakimenko, V.

    2012-12-21

    The X-ray spectrum emitted during relativistic non-linear inverse Compton scattering is angularly resolved, and energy analyzed through the use of K-edge and attenuation filters. A 0.5 nC electron beam of 65 MeV energy was employed, colliding with a highly intense CO{sub 2} laser of normalized vector potential a{sub L}{approx}0.5. In this experiment, 2nd harmonic radiation was clearly observed. In addition, evidence for the 3rd harmonic component of the radiation, having radiation angle of < 1/{gamma} has been found. This measurement represents a significant step forward in experimental understanding the electrodynamics of ICS in the nonlinear regime.

  5. Constraining the Parameters of Kpc-scale, Relativistic, Inverse Compton X-ray Jets in AGN

    NASA Astrophysics Data System (ADS)

    Schwartz, Daniel A.; Birkinshaw, M.; Worrall, D. M.

    2012-01-01

    The X-ray emission from extended, kpc-scale jets is commonly explained as inverse Compton scattering of the cosmic microwave background (CMB) by the same population of electrons that emit the GHz radio spectrum. The radio and X-ray flux densities, and the assumption of equipartition of magnetic and relativisitic particle energy density, give three constraints to estimate four quantities of interest: the magnetic field, relativistic electron density, bulk Lorentz factor, and angle of the jet to our line of sight. Additional assumptions, such as setting the Lorentz factor equal to the Doppler factor, are generally used, e.g., to deduce the kinetic flux along the jet. We allow the angle to the line of sight to be a free parameter, and suggest a new constraint on the Lorentz factor and therefore also the Doppler factor. As the Lorentz factor increases, the photons we receive are increasingly those emitted back towards the AGN nucleus in the jet rest frame. However the cone of enhanced CMB density lies increasingly in the opposite direction. Eventually these photons no longer fall in the small cone satisfying the head-on approximation, which is built into the expressions for inverse-Compton emissivity, and the emitted spectrum would no longer have the standard form. Accordingly, the data can be used to deduce an upper limit to the Lorentz factor as a function of the angle to the line of sight. This research was funded in part by Chandra grant GO7-8107X

  6. Non-thermal emission from relativistic MHD simulations of pulsar wind nebulae: from synchrotron to inverse Compton

    NASA Astrophysics Data System (ADS)

    Volpi, D.; Del Zanna, L.; Amato, E.; Bucciantini, N.

    2008-07-01

    Aims: We develop a set of diagnostic tools for synchrotron-emitting sources, presented in a previous paper, to include a computation of inverse-Compton radiation from the same relativistic particles that give rise to the synchrotron emission. For the first time, we then study the gamma-ray emission properties of Pulsar Wind Nebulae, in the context of the axisymmetric jet-torus scenario. Methods: We evolve the relativistic MHD equations and the maximum energy of the emitting particles, including adiabatic and synchrotron losses along streamlines. The particle energy distribution function is split into two components: one corresponds to radio-emitting electrons, which are interpreted to be a relic population that is born at the outburst of the supernova, and the other is associated with a wind population that is continuously accelerated at the termination shock and emits up to the gamma-ray band. The inverse Compton emissivity is calculated using the general Klein-Nishina differential cross-section and three different photon targets for the relativistic particles are considered: the nebular synchrotron photons, photons associated with the far-infrared thermal excess, and the cosmic microwave background. Results: When the method is applied to the simulations that match the optical and X-ray morphology of the Crab Nebula, the overall synchrotron spectrum can only be fitted assuming an excess of injected particles and a steeper power law (E-2.7) with respect to previous models. The resulting TeV emission has then the correct shape but is in excess of the data. This is related to the magnetic-field structure in the nebula, derived using simulations: in particular, the field is strongly compressed close to the termination shock, but with a lower than expected volume average. The jet-torus structure is also found to be visible clearly in high-resolution gamma-ray synthetic maps. We present a preliminary exploration of time variability in X- and gamma-rays. We find

  7. Simple analytical approximations for treatment of inverse Compton scattering of relativistic electrons in the blackbody radiation field

    SciTech Connect

    Khangulyan, D.; Kelner, S. R. E-mail: Felix.Aharonian@mpi-hd.mpg.de

    2014-03-10

    The inverse Compton (IC) scattering of relativistic electrons is one of the major gamma-ray production mechanisms in different environments. Often, the target photons for IC scattering are dominated by blackbody (or graybody) radiation. In this case, the precise treatment of the characteristics of IC radiation requires numerical integrations over the Planckian distribution. Formally, analytical integrations are also possible but they result in series of several special functions; this limits the efficiency of usage of these expressions. The aim of this work is the derivation of approximate analytical presentations that would provide adequate accuracy for the calculations of the energy spectra of upscattered radiation, the rate of electron energy losses, and the mean energy of emitted photons. Such formulae have been obtained by merging the analytical asymptotic limits. The coefficients in these expressions are calculated via the least-squares fitting of the results of numerical integrations. The simple analytical presentations, obtained for both the isotropic and anisotropic target radiation fields, provide adequate (as good as 1%) accuracy for broad astrophysical applications.

  8. Inversions

    ERIC Educational Resources Information Center

    Brown, Malcolm

    2009-01-01

    Inversions are fascinating phenomena. They are reversals of the normal or expected order. They occur across a wide variety of contexts. What do inversions have to do with learning spaces? The author suggests that they are a useful metaphor for the process that is unfolding in higher education with respect to education. On the basis of…

  9. Incidental Auditory Category Learning

    PubMed Central

    Gabay, Yafit; Dick, Frederic K.; Zevin, Jason D.; Holt, Lori L.

    2015-01-01

    Very little is known about how auditory categories are learned incidentally, without instructions to search for category-diagnostic dimensions, overt category decisions, or experimenter-provided feedback. This is an important gap because learning in the natural environment does not arise from explicit feedback and there is evidence that the learning systems engaged by traditional tasks are distinct from those recruited by incidental category learning. We examined incidental auditory category learning with a novel paradigm, the Systematic Multimodal Associations Reaction Time (SMART) task, in which participants rapidly detect and report the appearance of a visual target in one of four possible screen locations. Although the overt task is rapid visual detection, a brief sequence of sounds precedes each visual target. These sounds are drawn from one of four distinct sound categories that predict the location of the upcoming visual target. These many-to-one auditory-to-visuomotor correspondences support incidental auditory category learning. Participants incidentally learn categories of complex acoustic exemplars and generalize this learning to novel exemplars and tasks. Further, learning is facilitated when category exemplar variability is more tightly coupled to the visuomotor associations than when the same stimulus variability is experienced across trials. We relate these findings to phonetic category learning. PMID:26010588

  10. Incidental and non-incidental thyroid microcarcinoma

    PubMed Central

    KALISZEWSKI, KRZYSZTOF; WOJTCZAK, BEATA; STRUTYŃSKA-KARPIŃSKA, MARTA; ŁUKIEŃCZUK, TADEUSZ; FORKASIEWICZ, ZDZISŁAW; DOMOSŁAWSKI, PAWEŁ

    2016-01-01

    There is no clear therapeutic approach for thyroid microcarcinoma (TMC). This may be as a consequence of recent observations that have reported biologically different types of TMC, which should be treated differently. The objective of the present study was to compare incidental TMC (ITMC) and non-incidental TMC (NITMC) in order to assess the differences in the incidence, diagnostic results, clinicopathological characteristics and surgical treatment. The study consisted of a retrospective chart review of 3,218 patients consecutively admitted and surgically treated in a single institution due to thyroid pathology. A total of 246 (7.64%) patients presented with a thyroid malignancy, and 97 (39.43%) of these individuals were diagnosed with TMC; 37 (38.14%) patients exhibited ITMC and 60 (61.86%) exhibited NITMC. All 37 (100.00%) patients with ITMC exhibited a papillary type of cancer. In the NITMC group, 1 (1.67%) patient presented with follicular microcarcinoma, 1 (1.67%) individual with papillary- and follicular-type microcarcinoma, 1 (1.67%) individual with medullary microcarcinoma, and the remaining 57 (95.00%) patients presented with papillary microcarcinoma. The number of younger patients (<45 years old) was higher in the NITMC group, but this difference was not significant (P=0.205). In all patients with ITMC, ultrasound-guided fine-needle aspiration biopsy did not reveal malignant processes. In the NITMC group, the number of larger tumors (>5 mm) was significantly higher compared with that in the ITMC group (P<0.001). ITMC was significantly associated with multinodular goiter (MNG) (P<0.001). Amongst the NITMC group, 18.33% of patients presented with cervical lymph node involvement (P<0.001). Overall, the incidence of TMC is high, and consists of ITMC and NITMC, although the prevalence of NITMC is higher than that of ITMC. The majority of ITMCs and NITMCs are composed of a papillary type of cancer. The majority of ITMCs have dimensions ≤5 mm in diameter and

  11. The incidental diagnosis.

    PubMed

    Silverberg, L I

    1999-04-01

    Incidental findings transcend medical practice. Two cases are discussed in which significant conditions were discovered during clinical examination for an unrelated disorder. The first case presents a disease reported for the first time in a male. Recent literature has alluded to missed diagnoses found only at autopsies. With cost constraint as a national theme, the appropriate use of technology presents a challenge to the physician. The cases discussed raise questions about the process of diagnosis. Both situations bring to light the limitations of clinical investigation early in the pathologic process.

  12. Relativistic Spin and Pseudospin Symmetries of Inversely Quadratic Yukawa-like plus Mobius Square Potentials Including a Coulomb-like Tensor Interaction

    NASA Astrophysics Data System (ADS)

    Ikot, Akpan N.; Maghsoodi, Elham; Zarrinkamar, Saber; Hassanabadi, Hassan

    2013-11-01

    The Dirac equation for the combined Mobius square and inversely quadratic Yukawa potentials including a Coulomb-like interaction term has been investigated in the presence of spin and pseudospin symmetries with arbitrary spin-orbit quantum number κ .We have obtained the explicit energy eigenvalues and the corresponding eigenfunctions by the framework of Nikiforov-Uvarov method.

  13. Loading relativistic Maxwell distributions in particle simulations

    SciTech Connect

    Zenitani, Seiji

    2015-04-15

    Numerical algorithms to load relativistic Maxwell distributions in particle-in-cell (PIC) and Monte-Carlo simulations are presented. For stationary relativistic Maxwellian, the inverse transform method and the Sobol algorithm are reviewed. To boost particles to obtain relativistic shifted-Maxwellian, two rejection methods are proposed in a physically transparent manner. Their acceptance efficiencies are ≈50% for generic cases and 100% for symmetric distributions. They can be combined with arbitrary base algorithms.

  14. Solution uniquity of an inverse VLF problem: A case-study of the polar, ground-based, VLF radio signal disturbances caused by the ultra-energetic relativistic electron precipitations and of their southern boundaries

    NASA Astrophysics Data System (ADS)

    Remenets, G. F.; Astafiev, A. M.

    2016-09-01

    Here we present the results of a case study of the rare, abnormal, qualitatively specific behavior of Aldra (northern Norway) and GBR (UK) VLF transmitter signals (10-16 kHz) received at Kola Peninsula. The abnormal amplitude and the phase disturbances of signals were used as a proxy for ultra-energetic relativistic (solar?) electron precipitation (URE, ∼100 MeV) into the middle polar atmosphere. The disturbances have been observed under quiet or moderately disturbed geomagnetic activity. Based on bearing results, it was established that the abnormal variations of the electric conductivity of ionized middle atmosphere (of a sporadic Ds layer under the regular ionosphere D layer) were characterized by the following: (i) the time function of height h(t) of an effective spherical waveguide between the Earth surface and the sporadic Ds layer shows a minimum value equal to ∼30 km and (ii) the reflection coefficient R(t) of radio wave with a grazing angle of incidence from a virtual boundary with height h(t) has a minimum value equal to ∼0.4. The southern boundaries of the ultra-energetic relativistic electron precipitations have been found as well. They turned out to be not southerly than 61 degree of magnetic latitude and similar to the ones obtained in our previous study of the events for other dates under the similar geophysical conditions although we do not know anything definite about the rigidity and density of the electron fluxes. A used calculation method of analysis is based on a necessary condition that a number n of input data should be greater than a number m of output parameter-functions. We have stated by numerical testing that a decrease of n from 6 to 4 generates a lack of uniqueness of an inverse VLF problem solution for m = 2. It is important for future VLF ground-based monitoring of the URE precipitation events.

  15. [Managing focal incidental renal lesions].

    PubMed

    Nicolau, C; Paño, B; Sebastià, C

    2016-01-01

    Incidental renal lesions are relatively common in daily radiological practice. It is important to know the different diagnostic possibilities for incidentally detected lesions, depending on whether they are cystic or solid. The management of cystic lesions is guided by the Bosniak classification. In solid lesions, the goal is to differentiate between renal cancer and benign tumors such as fat-poor angiomyolipoma and oncocytoma. Radiologists need to know the recommendations for the management of these lesions and the usefulness of the different imaging techniques and interventional procedures in function of the characteristics of the incidental lesion and the patient's life expectancy.

  16. PACS: effect on incidental findings.

    PubMed

    Green, Larissa

    2004-01-01

    Previous studies have addressed the increased volume of incidental findings when interpreting MRI lumbar spine studies after the implementation of a picture archiving and communication system (PACS). The purpose of this study is to confirm prior findings and contribute additional knowledge that supports the use of technology in complimenting the quality of patient care. Lumbar spine interpretations were reprinted from 900 studies and individually reviewed. These lumbar spine studies were performed on a 1.5-tesla magnet. Included were 300 consecutive lumbar spine reports over a two year period: four months prior to PACS introduction, four months during the transition to PACS, and four months post PACS implementation. Reports stating incidental findings were tabulated, along with the frequency patient gender, age, location (outpatient, inpatient or emergency room), reporting radiologist, specific finding and radiologist recommendations in each case were documented. The number of incidental findings increased from five pre-PACS to nine during the transition phase to PACS, followed by 11 post-PACS. This results in a maximum increase of 120 percent from pre- to post-PACS. The most common incidental findings include renal mass, cyst or lesions, aortic aneurysms and lymph node abnormalities. Statistical data confirms that the implementation of PACS into a radiology practice for MRI lumbar spine imaging appears to have a beneficial impact on the number of reported incidental findings and recommended follow-up studies.

  17. Ultrahigh-intensity inverse bremsstrahlung

    NASA Astrophysics Data System (ADS)

    Kostyukov, I. Yu.; Rax, J.-M.

    1999-01-01

    We study inverse bremsstrahlung in the ultrahigh intensity relativistic regime. The fully relativistic ultrahigh intensity absorption (emission) coefficient is derived for an arbitrary scattering potential and small-angle scattering. We find that in the Coulomb field case this absorption (emission) coefficient can be calculated as a function of the quiver energy, drift momentum, and impact parameter in two complementary regimes: (i) for remote collisions when the impact parameter is larger than the amplitude of the quiver motion, and (ii) for instantaneous collisions when the scattering time is shorter than the period of the wave. Both circular and linear polarizations are considered, and this study reveals that in this relativistic regime inverse bremsstrahlung absorption can be viewed as a harmonic Compton resonance heating of the laser-driven electron by the virtual photon of the ion Coulomb field. The relativistic modification of Marcuse's effect [Bell Syst. Tech. J. 41, 1557 (1962)] are also discussed, and relations with previous nonrelativistic results are elucidated.

  18. Relativistic diffusion

    NASA Astrophysics Data System (ADS)

    Haba, Z.

    2009-02-01

    We discuss relativistic diffusion in proper time in the approach of Schay (Ph.D. thesis, Princeton University, Princeton, NJ, 1961) and Dudley [Ark. Mat. 6, 241 (1965)]. We derive (Langevin) stochastic differential equations in various coordinates. We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form. We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution. We discuss drag terms leading to an equilibrium distribution. The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Jüttner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.

  19. Relativistic diffusion.

    PubMed

    Haba, Z

    2009-02-01

    We discuss relativistic diffusion in proper time in the approach of Schay (Ph.D. thesis, Princeton University, Princeton, NJ, 1961) and Dudley [Ark. Mat. 6, 241 (1965)]. We derive (Langevin) stochastic differential equations in various coordinates. We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form. We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution. We discuss drag terms leading to an equilibrium distribution. The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Jüttner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.

  20. Inverse compton effect: some consequences for quasars.

    PubMed

    Pfleiderer, J; Grewing, M

    1966-12-16

    The inverse Compton effect can transform enough energy of relativistic electrons into radiation so that an upper limit to the mean energy of the electrons is set. In quasars, the limit is too small to allow the production of any appreciable amount of synchrotron or inverse Compton radiation, unless either the distances are not cosmological or the lifetimes of the relativistic electrons are extremely short, of the order of hours.

  1. Relativistic diffusive motion in random electromagnetic fields

    NASA Astrophysics Data System (ADS)

    Haba, Z.

    2011-08-01

    We show that the relativistic dynamics in a Gaussian random electromagnetic field can be approximated by the relativistic diffusion of Schay and Dudley. Lorentz invariant dynamics in the proper time leads to the diffusion in the proper time. The dynamics in the laboratory time gives the diffusive transport equation corresponding to the Jüttner equilibrium at the inverse temperature β-1 = mc2. The diffusion constant is expressed by the field strength correlation function (Kubo's formula).

  2. Relativistic geodesy

    NASA Astrophysics Data System (ADS)

    Flury, J.

    2016-06-01

    Quantum metrology enables new applications in geodesy, including relativistic geodesy. The recent progress in optical atomic clocks and in long-distance frequency transfer by optical fiber together pave the way for using measurements of the gravitational frequency redshift for geodesy. The remote comparison of frequencies generated by calibrated clocks will allow for a purely relativistic determination of differences in gravitational potential and height between stations on Earth surface (chronometric leveling). The long-term perspective is to tie potential and height differences to atomic standards in order to overcome the weaknesses and inhomogeneity of height systems determined by classical spirit leveling. Complementarily, gravity measurements with atom interferometric setups, and satellite gravimetry with space borne laser interferometers allow for new sensitivities in the measurement of the Earth's gravity field.

  3. Relativistic klystrons

    SciTech Connect

    Allen, M.A.; Azuma, O.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Herrmannsfeldt, W.B.; Hoag, H.A.; Koontz, R.F.

    1989-03-01

    Experimental work is underway by a SLAC-LLNL-LBL collaboration to investigate the feasibility of using relativistic klystrons as a power source for future high gradient accelerators. Two different relativistic klystron configurations have been built and tested to date: a high grain multicavity klystron at 11.4 GHz and a low gain two cavity subharmonic buncher driven at 5.7 GHz. In both configurations power is extracted at 11.4 GHz. In order to understand the basic physics issues involved in extracting RF from a high power beam, we have used both a single resonant cavity and a multi-cell traveling wave structure for energy extraction. We have learned how to overcome our previously reported problem of high power RF pulse shortening, and have achieved peak RF power levels of 170 MW with the RF pulse of the same duration as the beam current pulse. 6 refs., 3 figs., 3 tabs.

  4. Relativistic Non-Thermal Bremsstrahlung Radiation

    NASA Astrophysics Data System (ADS)

    Zeković, Vladimir; Arbutina, Bojan; Dobardžić, Aleksandra; Pavlović, Marko Z.

    2013-11-01

    By applying a method of virtual quanta we derive formulae for relativistic non-thermal bremsstrahlung radiation from relativistic electrons as well as from protons and heavier particles with power-law momentum distribution N(p)dp = k p-qdp. We show that emission which originates from an electron scattering on an ion, represents the most significant component of relativistic non-thermal bremsstrahlung. Radiation from an ion scattering on electron, known as inverse bremsstrahlung, is shown to be negligible in overall non-thermal bremsstrahlung emission. These results arise from theory refinement, where we introduce the dependence of relativistic kinetic energy of an incident particle, upon the energy of scattered photon. In part, it is also a consequence of a different mass of particles and relativistic effects.

  5. Relativistic Astrophysics

    NASA Astrophysics Data System (ADS)

    Jones, Bernard J. T.; Markovic, Dragoljub

    1997-06-01

    Preface; Prologue: Conference overview Bernard Carr; Part I. The Universe At Large and Very Large Redshifts: 2. The size and age of the Universe Gustav A. Tammann; 3. Active galaxies at large redshifts Malcolm S. Longair; 4. Observational cosmology with the cosmic microwave background George F. Smoot; 5. Future prospects in measuring the CMB power spectrum Philip M. Lubin; 6. Inflationary cosmology Michael S. Turner; 7. The signature of the Universe Bernard J. T. Jones; 8. Theory of large-scale structure Sergei F. Shandarin; 9. The origin of matter in the universe Lev A. Kofman; 10. New guises for cold-dark matter suspects Edward W. Kolb; Part II. Physics and Astrophysics Of Relativistic Compact Objects: 11. On the unification of gravitational and inertial forces Donald Lynden-Bell; 12. Internal structure of astrophysical black holes Werner Israel; 13. Black hole entropy: external facade and internal reality Valery Frolov; 14. Accretion disks around black holes Marek A. Abramowicz; 15. Black hole X-ray transients J. Craig Wheeler; 16. X-rays and gamma rays from active galactic nuclei Roland Svensson; 17. Gamma-ray bursts: a challenge to relativistic astrophysics Martin Rees; 18. Probing black holes and other exotic objects with gravitational waves Kip Thorne; Epilogue: the past and future of relativistic astrophysics Igor D. Novikov; I. D. Novikov's scientific papers and books.

  6. Factors influencing incidental representation of previously unknown conservation features in marine protected areas.

    PubMed

    Bridge, Tom C L; Grech, Alana M; Pressey, Robert L

    2016-02-01

    Spatially explicit information on species distributions for conservation planning is invariably incomplete; therefore, the use of surrogates is required to represent broad-scale patterns of biodiversity. Despite significant interest in the effectiveness of surrogates for predicting spatial distributions of biodiversity, few researchers have explored questions involving the ability of surrogates to incidentally represent unknown features of conservation interest. We used the Great Barrier Reef marine reserve network to examine factors affecting incidental representation of conservation features that were unknown at the time the reserve network was established. We used spatially explicit information on the distribution of 39 seabed habitats and biological assemblages and the conservation planning software Marxan to examine how incidental representation was affected by the spatial characteristics of the features; the conservation objectives (the minimum proportion of each feature included in no-take areas); the spatial configuration of no-take areas; and the opportunity cost of conservation. Cost was closely and inversely correlated to incidental representation. However, incidental representation was achieved, even in a region with only coarse-scale environmental data, by adopting a precautionary approach that explicitly considered the potential for unknown features. Our results indicate that incidental representation is enhanced by partitioning selection units along biophysical gradients to account for unknown within-feature variability and ensuring that no-take areas are well distributed throughout the region; by setting high conservation objectives that (in this case >33%) maximize the chances of capturing unknown features incidentally; and by carefully considering the designation of cost to planning units when using decision-support tools for reserve design. The lessons learned from incidental representation in the Great Barrier Reef have implications for

  7. Incidental Meningiomas: Management in the Neuroimaging Era.

    PubMed

    Spasic, Marko; Pelargos, Panayiotis E; Barnette, Natalie; Bhatt, Nikhilesh S; Lee, Seung James; Ung, Nolan; Gopen, Quinton; Yang, Isaac

    2016-04-01

    The number of patient imaging studies has increased because of precautious physicians ordering scans when a vague symptom is presented; subsequently, the number of incidental meningiomas detected has increased as well. These brain tumors do not present with related symptoms and are usually small. MRI and computed tomographic scans most frequently capture incidental meningiomas. Incidental meningiomas are managed with observation, radiation, and surgical resection. Ultimately, a conservative approach is recommended, such as observing an incidental meningioma and then only radiating if the tumor displays growth, whereas a surgical approach is to be used only when proven necessary. PMID:27012387

  8. 75 FR 80773 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-23

    ... Incidental to Specified Activities; Taking Marine Mammals Incidental to Space Vehicle and Missile Launch... to launching space launch vehicles, long-range ballistic target missiles, and other smaller missile... small numbers of marine mammals incidental to launching space launch vehicles, long-range...

  9. 77 FR 27321 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-09

    ... of an incidental harassment authorization. SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) regulations, notification is hereby given that NMFS has issued an Incidental Harassment Authorization (IHA) to Shell Gulf of Mexico Inc. (Shell) to take marine mammals, by harassment, incidental...

  10. Time parameters and Lorentz transformations of relativistic stochastic processes.

    PubMed

    Dunkel, Jörn; Hänggi, Peter; Weber, Stefan

    2009-01-01

    Rules for the transformation of time parameters in relativistic Langevin equations are derived and discussed. In particular, it is shown that, if a coordinate-time-parametrized process approaches the relativistic Jüttner-Maxwell distribution, the associated proper-time-parametrized process converges to a modified momentum distribution, differing by a factor proportional to the inverse energy. PMID:19256987

  11. Incidental isolated pancreatic hydatid cyst.

    PubMed

    Kısaoğlu, Abdullah; Özoğul, Bünyami; Atamanalp, Sabri Selçuk; Pirimoğlu, Berhan; Aydınlı, Bülent; Korkut, Ercan

    2015-03-01

    Isolated pancreatic hydatid cysts are a rare parasitic disease even in endemic areas. It is difficult to discriminate primary pancreatic hydatid cysts from other cystic and solid lesions of the pancreas. This is a case report of an incidental isolated pancreatic hydatid cyst. A heterogeneous cystic lesion in the body of the pancreas was identified on magnetic resonance imaging of a patient previously diagnosed patient with cholelithiasis, and because of the malignant possibility of the lesion, splenectomy with distal pancreatectomy and cholecystectomy was performed. The histopathologic diagnosis was reported as a hydatid cyst. Pancreatic hydatid cysts should be kept in mind in the differential diagnosis of pancreatic pseudocysts and cystic malignancies.

  12. 12 CFR 975.4 - Incidental powers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Incidental powers. 975.4 Section 975.4 Banks and Banking FEDERAL HOUSING FINANCE BOARD MISCELLANEOUS FEDERAL HOME LOAN BANK OPERATIONS AND AUTHORITIES COLLECTION, SETTLEMENT, AND PROCESSING OF PAYMENT INSTRUMENTS § 975.4 Incidental powers....

  13. Incidental fleurodeoxyglucose uptake in the prostate

    PubMed Central

    Wong, W L; Moule, R N; Nunan, T

    2010-01-01

    This commentary confirms the rarity of prostatic cancer associated with incidental prostatic fleurodeoxyglucose (FDG) uptake. The study adds to the literature by showing that even if a prostate lesion is FDG avid it is unlikely to be due to cancer. The commentary considers the management of incidental prostate FDG uptake on the basis of the available evidence. PMID:20965899

  14. 47 CFR 15.13 - Incidental radiators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Incidental radiators. 15.13 Section 15.13 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES General § 15.13 Incidental radiators. Manufacturers of these devices shall employ good engineering practices to minimize the risk...

  15. 47 CFR 15.13 - Incidental radiators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Incidental radiators. 15.13 Section 15.13 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES General § 15.13 Incidental radiators. Manufacturers of these devices shall employ good engineering practices to minimize the risk...

  16. 47 CFR 15.13 - Incidental radiators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Incidental radiators. 15.13 Section 15.13 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES General § 15.13 Incidental radiators. Manufacturers of these devices shall employ good engineering practices to minimize the risk...

  17. 47 CFR 15.13 - Incidental radiators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Incidental radiators. 15.13 Section 15.13 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES General § 15.13 Incidental radiators. Manufacturers of these devices shall employ good engineering practices to minimize the risk...

  18. 47 CFR 15.13 - Incidental radiators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Incidental radiators. 15.13 Section 15.13 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES General § 15.13 Incidental radiators. Manufacturers of these devices shall employ good engineering practices to minimize the risk...

  19. 25 CFR 700.199 - Incidental expenses.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Incidental expenses. 700.199 Section 700.199 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Incidental... determined to be part of the debt service or finance charge under 15 U.S.C. 131-1641 and Regulation Z (12...

  20. 12 CFR 975.4 - Incidental powers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 8 2012-01-01 2012-01-01 false Incidental powers. 975.4 Section 975.4 Banks and Banking FEDERAL HOUSING FINANCE BOARD MISCELLANEOUS FEDERAL HOME LOAN BANK OPERATIONS AND AUTHORITIES COLLECTION, SETTLEMENT, AND PROCESSING OF PAYMENT INSTRUMENTS § 975.4 Incidental powers....

  1. 12 CFR 1271.4 - Incidental powers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 10 2014-01-01 2014-01-01 false Incidental powers. 1271.4 Section 1271.4 Banks and Banking FEDERAL HOUSING FINANCE AGENCY FEDERAL HOME LOAN BANKS MISCELLANEOUS FEDERAL HOME LOAN... Incidental powers. In connection with the collection, processing, and settlement of items and...

  2. 12 CFR 975.4 - Incidental powers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 8 2013-01-01 2013-01-01 false Incidental powers. 975.4 Section 975.4 Banks and Banking FEDERAL HOUSING FINANCE BOARD MISCELLANEOUS FEDERAL HOME LOAN BANK OPERATIONS AND AUTHORITIES COLLECTION, SETTLEMENT, AND PROCESSING OF PAYMENT INSTRUMENTS § 975.4 Incidental powers....

  3. 12 CFR 975.4 - Incidental powers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 7 2011-01-01 2011-01-01 false Incidental powers. 975.4 Section 975.4 Banks and Banking FEDERAL HOUSING FINANCE BOARD MISCELLANEOUS FEDERAL HOME LOAN BANK OPERATIONS AND AUTHORITIES COLLECTION, SETTLEMENT, AND PROCESSING OF PAYMENT INSTRUMENTS § 975.4 Incidental powers....

  4. Animation, Incidental Learning, and Continuing Motivation.

    ERIC Educational Resources Information Center

    Rieber, Lloyd P.

    1991-01-01

    Effects of animated graphics presentations on incidental learning and the degree to which various computer practice activities contain intrinsically motivating characteristics were studied with 70 fourth graders learning about Newton's laws of motion. Incidental learning occurred without sacrifice of intentional learning. Students were highly…

  5. Relativistic fluid dynamics. Proceedings.

    NASA Astrophysics Data System (ADS)

    Anile, A. M.; Choquet-Bruhat, Y.

    Contents: 1. Covariant theory of conductivity in ideal fluid or solid media (B. Carter). 2. Hamiltonian techniques for relativistic fluid dynamics and stability theory (D. D. Holm). 3. Covariant fluid mechanics and thermodynamics: an introduction (W. Israel). 4. Relativistic plasmas (H. Weitzner). 5. An improved relativistic warm plasma model (A. M. Anile, S. Pennisi). 6. Relativistic extended thermodynamics II (I. Müller). 7. Relativistic extended thermodynamics: general assumptions and mathematical procedure (T. Ruggeri). 8. Relativistic hydrodynamics and heavy ion reactions (D. Strottman). 9. Some problems in relativistic hydrodynamics (C. G. van Weert).

  6. Focal liver lesions found incidentally.

    PubMed

    Algarni, Abdullah A; Alshuhri, Abdullah H; Alonazi, Majed M; Mourad, Moustafa Mabrouk; Bramhall, Simon R

    2016-03-28

    Incidentally found focal liver lesions are a common finding and a reason for referral to hepatobiliary service. They are often discovered in patients with history of liver cirrhosis, colorectal cancer, incidentally during work up for abdominal pain or in a trauma setting. Specific points should considered during history taking such as risk factors of liver cirrhosis; hepatitis, alcohol consumption, substance exposure or use of oral contraceptive pills and metabolic syndromes. Full blood count, liver function test and tumor markers can act as a guide to minimize the differential diagnosis and to categorize the degree of liver disease. Imaging should start with B-mode ultrasound. If available, contrast enhanced ultrasound is a feasible, safe, cost effective option and increases the ability to reach a diagnosis. Contrast enhanced computed tomography should be considered next. It is more accurate in diagnosis and better to study anatomy for possible operation. Contrast enhanced magnetic resonance is the gold standard with the highest sensitivity. If doubt still remains, the options are biopsy or surgical excision. PMID:27028805

  7. Incidental and online learning of melodic structure.

    PubMed

    Rohrmeier, Martin; Rebuschat, Patrick; Cross, Ian

    2011-06-01

    The cognition of music, like that of language, is partly rooted in enculturative processes of implicit and incidental learning. Musicians and nonmusicians alike are commonly found to possess detailed implicit knowledge of musical structure which is acquired incidentally through interaction with large samples of music. This paper reports an experiment combining the methodology of artificial grammar learning with musical acquisition of melodic structure. Participants acquired knowledge of grammatical melodic structures under incidental learning conditions in both experimental and untrained control conditions. Subsequent analysis indicates a large effect of unsupervised online learning in the experimental and control group throughout the course of the testing phase suggesting an effective ongoing learning process. Musicians did not outperform nonmusicians, indicating that musical expertise is not advantageous for the learning of a new, unfamiliar melodic system. Confidence ratings suggest that participants became aware of the knowledge guiding their classification performance despite the incidental learning conditions.

  8. Small Incidental Renal Masses in Adults

    PubMed Central

    Al-Marhoon, Mohammed S

    2010-01-01

    Incidental renal tumours are becoming an important clinical problem that many physicians will need to deal with. A good knowledge of the nature of these tumours and how to manage them is therefore needed. The aim of this paper is to review the literature about incidental renal tumours in adults. Many incidentally discovered small renal tumours (<4 cm) are benign and of low stage, grade and progression potential. The preferred management in young fit patients is open or laparoscopic nephron-sparing surgery. Treatment alternatives include needle-ablative therapies and surveillance in elderly unfit patients. Tumour renal biopsy is encouraged prior to needle-ablative therapy and surveillance. Awareness about incidental renal masses and their management is essential for treating doctors. PMID:21509229

  9. Relativistic electron beam generator

    DOEpatents

    Mooney, L.J.; Hyatt, H.M.

    1975-11-11

    A relativistic electron beam generator for laser media excitation is described. The device employs a diode type relativistic electron beam source having a cathode shape which provides a rectangular output beam with uniform current density.

  10. 75 FR 25729 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-07

    ...NMFS received an application from Shell Offshore Inc. (Shell) for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to offshore exploration drilling on Outer Continental Shelf (OCS) leases in the Chukchi Sea, Alaska. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue an IHA to Shell to take, by......

  11. 77 FR 49921 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-17

    ...NMFS received an application from ION Geophysical (ION) for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment only, incidental to a proposed marine seismic survey in the Beaufort and Chukchi Seas, Alaska, between October and December 2012. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue an IHA to ION to......

  12. 78 FR 12541 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-22

    ...NMFS received an application from ConocoPhillips Company (COP) for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to offshore exploration drilling on Outer Continental Shelf (OCS) leases in the Chukchi Sea, Alaska. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue an IHA to COP to take, by......

  13. 78 FR 37209 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC564 Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Marine Seismic Survey in the Beaufort Sea,...

  14. Incidental sequence learning across the lifespan.

    PubMed

    Weiermann, Brigitte; Meier, Beat

    2012-06-01

    The purpose of the present study was to investigate incidental sequence learning across the lifespan. We tested 50 children (aged 7-16), 50 young adults (aged 20-30), and 50 older adults (aged >65) with a sequence learning paradigm that involved both a task and a response sequence. After several blocks of practice, all age groups slowed down when the training sequences were removed, providing indirect evidence for sequence learning. This performance slowing was comparable between groups, indicating no age-related differences. However, when explicit sequence knowledge was considered, age effects were found. For both children and older adults with no or only little explicit knowledge, incidental sequence learning was largely reduced and statistically not significant. In contrast, young adults showed sequence learning irrespective of the amount of explicit knowledge. These results indicate that different learning processes are involved in incidental sequence learning depending on age.

  15. Negative incidental emotions augment fairness sensitivity.

    PubMed

    Liu, Cuizhen; Chai, Jing Wen; Yu, Rongjun

    2016-01-01

    Previous studies have shown that task-unrelated emotions induced incidentally exert carryover effects on individuals' subsequent decisions in financial negotiations. However, the specificity of these emotion effects are not clear. In three experiments, we systematically investigated the role of seven transiently induced basic emotions (disgust, sadness, anger, fear, happiness, surprise and neutral) on rejection of unfair offers using the ultimatum game. We found that all negative emotions (disgust, sadness, anger and fear), but not happiness or surprise, significantly increased rejection rates, suggesting that the effect of incidental negative emotions on fairness is not specific to the type of negative emotion. Our findings highlight the role of fleeting emotions in biasing decision-making processes and suggest that all incidental negative emotions exert similar effects on fairness sensitivity, possibly by potentiating attention towards negative aspects of the situation. PMID:27101931

  16. Negative incidental emotions augment fairness sensitivity

    PubMed Central

    Liu, Cuizhen; Chai, Jing Wen; Yu, Rongjun

    2016-01-01

    Previous studies have shown that task-unrelated emotions induced incidentally exert carryover effects on individuals’ subsequent decisions in financial negotiations. However, the specificity of these emotion effects are not clear. In three experiments, we systematically investigated the role of seven transiently induced basic emotions (disgust, sadness, anger, fear, happiness, surprise and neutral) on rejection of unfair offers using the ultimatum game. We found that all negative emotions (disgust, sadness, anger and fear), but not happiness or surprise, significantly increased rejection rates, suggesting that the effect of incidental negative emotions on fairness is not specific to the type of negative emotion. Our findings highlight the role of fleeting emotions in biasing decision-making processes and suggest that all incidental negative emotions exert similar effects on fairness sensitivity, possibly by potentiating attention towards negative aspects of the situation. PMID:27101931

  17. Trans-Relativistic Particle Acceleration in Astrophysical Plasmas

    NASA Astrophysics Data System (ADS)

    Becker, Peter A.; Subramanian, P.

    2014-01-01

    Trans-relativistic particle acceleration due to Fermi interactions between charged particles and MHD waves helps to power the observed high-energy emission in AGN transients and solar flares. The trans-relativistic acceleration process is challenging to treat analytically due to the complicated momentum dependence of the momentum diffusion coefficient. For this reason, most existing analytical treatments of particle acceleration assume that the injected seed particles are already relativistic, and therefore they are not suited to study trans-relativistic acceleration. The lack of an analytical model has forced workers to rely on numerical simulations to obtain particle spectra describing the trans-relativistic case. In this work we present the first analytical solution to the global, trans-relativistic problem describing the acceleration of seed particles due to hard-sphere collisions with MHD waves. The new results include the exact solution for the steady-state Green's function resulting from the continual injection of monoenergetic seed particles with an arbitrary energy. We also introduce an approximate treatment of the trans-relativistic acceleration process based on a hybrid form for the momentum diffusion coefficient, given by the sum of the two asymptotic forms. We refer to this process as "quasi hard-sphere scattering." The main advantage of the hybrid approximation is that it allows the extension of the physical model to include (i) the effects of synchrotron and inverse-Compton losses and (ii) time dependence. The new analytical results can be used to model the trans-relativistic acceleration of particles in AGN and solar environments, and can also be used to compute the spectra of the associated synchrotron and inverse-Compton emission. Applications of both types are discussed. We highlight (i) relativistic ion acceleration in black hole accretion coronae, and (ii) the production of gyrosynchrotron microwave emission due to relativistic electron

  18. A New Analytical Model for Trans-Relativistic Particle Acceleration

    NASA Astrophysics Data System (ADS)

    Becker, Peter A.

    2011-01-01

    Most existing analytical models describing the second-order Fermi acceleration of relativistic particles due to collisions with MHD waves assume that the injected seed particles are already highly relativistic, despite the fact that the most prevalent source of particles is usually the local thermal background, which is typically a non-relativistic gas. This presents a problem because the momentum dependence of the momentum diffusion coefficient describing the interaction between the particles and the MHD waves is qualitatively different in the non-relativistic and highly relativistic limits. Since the existing analytical models are not able to address this situation, workers have had to rely on numerical simulations to obtain particle spectra describing the trans-relativistic case. In this work we present the first analytical solution to the global, trans-relativistic problem, obtained by using a hybrid form for the momentum diffusion coefficient, given by the sum of the two asymptotic forms. The model also incorporates the appropriate momentum dependence for the particle escape timescale, and the effect of synchrotron and inverse-Compton losses, which are critical for establishing the location of the high-energy cutoff in the particle spectrum. The results can be used to model the acceleration of particles in AGN and solar environments, and can also be used to compute the spectra of the associated synchrotron and inverse-Compton emission. Applications of both types are discussed.

  19. Relativistic Linear Restoring Force

    ERIC Educational Resources Information Center

    Clark, D.; Franklin, J.; Mann, N.

    2012-01-01

    We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

  20. Relativistic Guiding Center Equations

    SciTech Connect

    White, R. B.; Gobbin, M.

    2014-10-01

    In toroidal fusion devices it is relatively easy that electrons achieve relativistic velocities, so to simulate runaway electrons and other high energy phenomena a nonrelativistic guiding center formalism is not sufficient. Relativistic guiding center equations including flute mode time dependent field perturbations are derived. The same variables as used in a previous nonrelativistic guiding center code are adopted, so that a straightforward modifications of those equations can produce a relativistic version.

  1. 21 CFR 1307.13 - Incidental manufacture of controlled substances.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Incidental manufacture of controlled substances... MISCELLANEOUS Special Exceptions for Manufacture and Distribution of Controlled Substances § 1307.13 Incidental manufacture of controlled substances. Any registered manufacturer who, incidentally but...

  2. 21 CFR 1307.13 - Incidental manufacture of controlled substances.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 9 2013-04-01 2013-04-01 false Incidental manufacture of controlled substances... MISCELLANEOUS Special Exceptions for Manufacture and Distribution of Controlled Substances § 1307.13 Incidental manufacture of controlled substances. Any registered manufacturer who, incidentally but...

  3. 21 CFR 1307.13 - Incidental manufacture of controlled substances.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Incidental manufacture of controlled substances... MISCELLANEOUS Special Exceptions for Manufacture and Distribution of Controlled Substances § 1307.13 Incidental manufacture of controlled substances. Any registered manufacturer who, incidentally but...

  4. 21 CFR 1307.13 - Incidental manufacture of controlled substances.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Incidental manufacture of controlled substances... MISCELLANEOUS Special Exceptions for Manufacture and Distribution of Controlled Substances § 1307.13 Incidental manufacture of controlled substances. Any registered manufacturer who, incidentally but...

  5. 21 CFR 1307.13 - Incidental manufacture of controlled substances.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 9 2014-04-01 2014-04-01 false Incidental manufacture of controlled substances... MISCELLANEOUS Special Exceptions for Manufacture and Distribution of Controlled Substances § 1307.13 Incidental manufacture of controlled substances. Any registered manufacturer who, incidentally but...

  6. 76 FR 74805 - Draft Environmental Assessment, Incidental Take Plan, and Application for an Incidental Take...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-01

    ... application from the MDIFW for an incidental take permit in a November 9, 2011, Federal Register notice (76 FR.... ADDRESSES: Send comments by U.S. mail to Attn: Lynx HCP, Laury Zicari, Field Supervisor, U.S. Fish...

  7. 78 FR 77433 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-23

    ... one elephant seal has been observed at Pigeon Point. California Sea Lion California sea lions are not... to PISCO to take marine mammals incidental to these same proposed activities (77 FR 72327, December...

  8. 76 FR 6406 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-04

    ...; proposed incidental harassment authorization; request for comments. SUMMARY: NMFS has received an application from the U.S. Navy (Navy) for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to construction activities as part of a pile replacement project....

  9. 76 FR 79409 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-21

    ...; proposed incidental harassment authorization; request for comments. SUMMARY: NMFS has received an application from the U.S. Navy (Navy) for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to construction activities as part of a wharf construction...

  10. 77 FR 25408 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-30

    ...; proposed incidental harassment authorization; request for comments. SUMMARY: NMFS has received an application from the U.S. Navy (Navy) for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to construction activities as part of a pile replacement project....

  11. 76 FR 4300 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ...; proposed incidental harassment authorization; request for comments. SUMMARY: NMFS has received an application from the U.S. Navy (Navy) for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to pile driving activities as part of a test pile program. Pursuant to...

  12. Incidental Learning of Sex Role Characteristics.

    ERIC Educational Resources Information Center

    Kinsell-Rainey, Lynn W.

    The content and process of incidental learning of sex role related characteristics through play behavior was explored in a study of more than 6000 toys sold by Sears, Roebuck & Company between 1900 and 1970, as represented in their mail order catalogs. Sixty percent of all toys were sex typed by Sears. The nature of the play behavior associated…

  13. Spatial Reference Frame of Incidentally Learned Attention

    ERIC Educational Resources Information Center

    Jiang, Yuhong V.; Swallow, Khena M.

    2013-01-01

    Visual attention prioritizes information presented at particular spatial locations. These locations can be defined in reference frames centered on the environment or on the viewer. This study investigates whether incidentally learned attention uses a viewer-centered or environment-centered reference frame. Participants conducted visual search on a…

  14. Incidental Sequence Learning across the Lifespan

    ERIC Educational Resources Information Center

    Weiermann, Brigitte; Meier, Beat

    2012-01-01

    The purpose of the present study was to investigate incidental sequence learning across the lifespan. We tested 50 children (aged 7-16), 50 young adults (aged 20-30), and 50 older adults (aged >65) with a sequence learning paradigm that involved both a task and a response sequence. After several blocks of practice, all age groups slowed down…

  15. Incidental Education (for Women) in Rural Communities.

    ERIC Educational Resources Information Center

    Crosby, Valmai

    The Country Women's Association (CWA) is a nationwide Australian group that started in the 1920s in response to isolated women's need to socialize. The group's activities have expanded greatly over time. It distributes essential food and clothing to needy rural families, and its extensive involvement in incidental education for women includes…

  16. Incidental Learning in a Complex Clinical Workplace

    ERIC Educational Resources Information Center

    Harner, Michael Dean

    2013-01-01

    Workplace learning is complex as employees engage in activities to meet organizational objectives. This study investigates incidental learning in a complex clinical environment. The systems created to collect information and perform patient-visit functions involve several people who have distinct roles that can impact how subsequent people in the…

  17. Incidental fear cues increase monetary loss aversion.

    PubMed

    Schulreich, Stefan; Gerhardt, Holger; Heekeren, Hauke R

    2016-04-01

    In many everyday decisions, people exhibit loss aversion-a greater sensitivity to losses relative to gains of equal size. Loss aversion is thought to be (at least partly) mediated by emotional--in particular, fear-related--processes. Decision research has shown that even incidental emotions, which are unrelated to the decision at hand, can influence decision making. The effect of incidental fear on loss aversion, however, is thus far unclear. In two studies, we experimentally investigated how incidental fear cues, presented during (Study 1) or before (Study 2) choices to accept or reject mixed gambles over real monetary stakes, influence monetary loss aversion. We find that the presentation of fearful faces, relative to the presentation of neutral faces, increased risk aversion-an effect that could be attributed to increased loss aversion. The size of this effect was moderated by psychopathic personality: Fearless dominance, in particular its interpersonal facet, but not self-centered impulsivity, attenuated the effect of incidental fear cues on loss aversion, consistent with reduced fear reactivity. Together, these results highlight the sensitivity of loss aversion to the affective context.

  18. Incidental Foreign Language Acquisition from Media Exposure

    ERIC Educational Resources Information Center

    Kuppens, An H.

    2010-01-01

    A number of experimental studies have demonstrated the incidental acquisition of a foreign language by children and adolescents when watching foreign language television. While such experiments can only establish short-term effects, this article investigates the extent to which children's foreign language skills benefit from their long-term…

  19. Statistical learning under incidental versus intentional conditions.

    PubMed

    Arciuli, Joanne; Torkildsen, Janne von Koss; Stevens, David J; Simpson, Ian C

    2014-01-01

    Statistical learning (SL) studies have shown that participants are able to extract regularities in input they are exposed to without any instruction to do so. This and other findings, such as the fact that participants are often unable to verbalize their acquired knowledge, suggest that SL can occur implicitly or incidentally. Interestingly, several studies using the related paradigms of artificial grammar learning and serial response time tasks have shown that explicit instructions can aid learning under certain conditions. Within the SL literature, however, very few studies have contrasted incidental and intentional learning conditions. The aim of the present study was to investigate the effect of having prior knowledge of the statistical regularities in the input when undertaking a task of visual sequential SL. Specifically, we compared the degree of SL exhibited by participants who were informed (intentional group) versus those who were uninformed (incidental group) about the presence of embedded triplets within a familiarization stream. Somewhat surprisingly, our results revealed that there were no statistically significant differences (and only a small effect size) in the amount of SL exhibited between the intentional versus the incidental groups. We discuss the ways in which this result can be interpreted and suggest that short presentation times for stimuli in the familiarization stream in our study may have limited the opportunity for explicit learning. This suggestion is in line with recent research revealing a statistically significant difference (and a large effect size) between intentional versus incidental groups using a very similar visual sequential SL task, but with longer presentation times. Finally, we outline a number of directions for future research. PMID:25071692

  20. Incidentally discovered giant mucocele of the appendix.

    PubMed

    Harris, Syed Hasan; Khan, Roobina; Ansari, Maulana Mohammad; Maheshwari, Veena

    2014-11-01

    Mucocele of the appendix is a rare but well-recognized entity that can mimic several common clinical conditions or present as an incidental radiological or surgical finding at laparotomy. Mucoceles are characterized by distension of the lumen due to accumulation of mucoid substance. They can result from mucosal hyperplasia, mucinous cystadenoma, or mucinous cystadenocarcinoma. If untreated, they may rupture producing the potentially fatal entity Pseudomyxoma peritonei, which is difficult to treat both surgically or medically. Appendectomy is used for simple mucocele or for cystadenoma. Preoperative diagnosis of a mucocele is helpful at the time of surgical intervention with careful mobilization, particularly of large lesions reducing the possibility of rupture and complications. The authors report a case of a 65-year-old man presenting with peritonitis due to a pre-pyloric gastric perforation also having an incidental giant mucocele of the appendix.

  1. Incidental Anterior Cruciate Ligament Calcification: Case Report

    PubMed Central

    Hayashi, Hisami; Fischer, Hans

    2016-01-01

    The calcification of knee ligaments is a finding noted only in a handful of case reports. The finding of an anterior cruciate ligament calcification has been reported once in the literature. Comparable studies involving the posterior cruciate ligament, medial collateral ligament and an ossicle within the anterior cruciate ligament are likewise discussed in reports of symptomatic patients. We report a case of incidentally discovered anterior cruciate ligament calcification. We discuss the likely etiology and clinical implications of this finding. PMID:27200163

  2. Incidental Anterior Cruciate Ligament Calcification: Case Report.

    PubMed

    Hayashi, Hisami; Fischer, Hans

    2016-03-01

    The calcification of knee ligaments is a finding noted only in a handful of case reports. The finding of an anterior cruciate ligament calcification has been reported once in the literature. Comparable studies involving the posterior cruciate ligament, medial collateral ligament and an ossicle within the anterior cruciate ligament are likewise discussed in reports of symptomatic patients. We report a case of incidentally discovered anterior cruciate ligament calcification. We discuss the likely etiology and clinical implications of this finding.

  3. Incidental finding of lymphoma after septoplasty

    PubMed Central

    Tajudeen, Bobby A.; Bhuta, Sunita M.; Palma Diaz, Miguel Fernando; Kedeshian, Paul A.; Suh, Jeffrey D.

    2016-01-01

    Introduction: Septoplasty, or surgical correction of the deviated septum, is an elective, routinely performed rhinologic procedure to address nasal airway obstruction. In many cases, resected septal cartilage and bone fragments are sent for pathologic review, although there is no consensus on this practice. We reported two cases of incidentally diagnosed lymphoma after elective septoplasty and discussed clinical presentation, diagnosis, and management. Methods: Retrospective chart review of two patients who underwent septoplasty at a tertiary academic medical center and found to have incidental lymphoma based on histopathology. Results: Two patients who underwent septoplasty had an incidental diagnosis of lymphoma on pathologic analysis. One patient was noted to have an S-shaped septal deviation that produced bilateral nasal obstruction. She underwent a difficult septoplasty, in which the mucoperichondrial flap was firmly adherent to the underlying septum and bone. Final pathology demonstrated diffuse large B-cell lymphoma. She was treated with chemoradiation and remained free of disease at 59 months. The other patient had a history of nasal trauma, which produced left septal deviation. He underwent an uncomplicated septoplasty, with pathology that demonstrated low-grade B-cell lymphoma. Because there was no evidence of active disease, the decision was made to not treat and to observe the patient clinically. Conclusions: This is the first reported series of septal lymphoma incidentally diagnosed on routine septoplasty. Although histopathologic review of specimens from routine nasal and sinus surgery is not routinely performed, this report highlighted the importance of this process, on a case-by-case basis, in detecting unexpected malignancies that otherwise were clinically silent. PMID:27470206

  4. Relativistic Gravity Research

    NASA Astrophysics Data System (ADS)

    Ehlers, Jürgen; Schäfer, Gerhard

    17 readable articles give a thorough and self-contained overview of recent developments in relativistic gravity research. The subjects covered are: gravitational lensing, the general relativistic n-body problem, observable effects in the solar system, gravitational waves and their interferometric detection, very-long-baseline interferometry, international atomic time, lunar laserranging measurements, measurement of the gravitomagnetic field of the Earth, fermion and boson stars and black holes with hair, rapidly rotating neutron stars, matter wave interferometry, and the laboratory test of Newton's law of gravity. Any scientist interested in experimentally or observatio- nally oriented relativistic gravity will read the book with profit. In addition, it is perfectly suited as a complementary text for courses on general relativity and relativistic astrophysics.

  5. Relativistic spherical plasma waves

    NASA Astrophysics Data System (ADS)

    Bulanov, S. S.; Maksimchuk, A.; Schroeder, C. B.; Zhidkov, A. G.; Esarey, E.; Leemans, W. P.

    2012-02-01

    Tightly focused laser pulses that diverge or converge in underdense plasma can generate wake waves, having local structures that are spherical waves. Here we study theoretically and numerically relativistic spherical wake waves and their properties, including wave breaking.

  6. Weakly relativistic plasma expansion

    SciTech Connect

    Fermous, Rachid Djebli, Mourad

    2015-04-15

    Plasma expansion is an important physical process that takes place in laser interactions with solid targets. Within a self-similar model for the hydrodynamical multi-fluid equations, we investigated the expansion of both dense and under-dense plasmas. The weakly relativistic electrons are produced by ultra-intense laser pulses, while ions are supposed to be in a non-relativistic regime. Numerical investigations have shown that relativistic effects are important for under-dense plasma and are characterized by a finite ion front velocity. Dense plasma expansion is found to be governed mainly by quantum contributions in the fluid equations that originate from the degenerate pressure in addition to the nonlinear contributions from exchange and correlation potentials. The quantum degeneracy parameter profile provides clues to set the limit between under-dense and dense relativistic plasma expansions at a given density and temperature.

  7. 12 CFR 721.2 - What is an incidental powers activity?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false What is an incidental powers activity? 721.2... INCIDENTAL POWERS § 721.2 What is an incidental powers activity? An incidental powers activity is one that is... activity meets the definition of an incidental power activity if the activity: (a) Is convenient or...

  8. Relativistic Quantum Scars

    SciTech Connect

    Huang, Liang; Lai Yingcheng; Ferry, David K.; Goodnick, Stephen M.; Akis, Richard

    2009-07-31

    The concentrations of wave functions about classical periodic orbits, or quantum scars, are a fundamental phenomenon in physics. An open question is whether scarring can occur in relativistic quantum systems. To address this question, we investigate confinements made of graphene whose classical dynamics are chaotic and find unequivocal evidence of relativistic quantum scars. The scarred states can lead to strong conductance fluctuations in the corresponding open quantum dots via the mechanism of resonant transmission.

  9. Exact Relativistic `Antigravity' Propulsion

    NASA Astrophysics Data System (ADS)

    Felber, Franklin S.

    2006-01-01

    The Schwarzschild solution is used to find the exact relativistic motion of a payload in the gravitational field of a mass moving with constant velocity. At radial approach or recession speeds faster than 3-1/2 times the speed of light, even a small mass gravitationally repels a payload. At relativistic speeds, a suitable mass can quickly propel a heavy payload from rest nearly to the speed of light with negligible stresses on the payload.

  10. General Relativistic and Newtonian White Dwarfs

    NASA Astrophysics Data System (ADS)

    Boshkayev, K.; Rueda, J. A.; Ruffini, R.; Siutsou, I.

    2015-01-01

    The properties of uniformly rotating white dwarfs (RWDs) are analyzed within the framework of Newton's gravity and general relativity. In both cases Hartle's formalism is applied to construct the internal and external solutions to the field equations. The white dwarf (WD) matter is described by the Chandrasekhar equation of state. The region of stability of RWDs is constructed taking into account the mass-shedding limit, inverse β-decay instability, and the boundary established by the turning points of constant angular momentum J sequences which separates stable from secularly unstable configurations. We found the minimum rotation period ˜ 0.28 s in both cases and maximum rotating masses ˜ 1.534M⊙ and ˜ 1.516M⊙ for the Newtonian and general relativistic WDs, respectively. By using the turning point method we show that general relativistic WDs can indeed be axisymmetrically unstable whereas the Newtonian WDs are stable.

  11. Anomalous magnetohydrodynamics in the extreme relativistic domain

    NASA Astrophysics Data System (ADS)

    Giovannini, Massimo

    2016-10-01

    The evolution equations of anomalous magnetohydrodynamics are derived in the extreme relativistic regime and contrasted with the treatment of hydromagnetic nonlinearities pioneered by Lichnerowicz in the absence of anomalous currents. In particular we explore the situation where the conventional vector currents are complemented by the axial-vector currents arising either from the pseudo-Nambu-Goldstone bosons of a spontaneously broken symmetry or because of finite fermionic density effects. After expanding the generally covariant equations in inverse powers of the conductivity, the relativistic analog of the magnetic diffusivity equation is derived in the presence of vortical and magnetic currents. While the anomalous contributions are generally suppressed by the diffusivity, they are shown to disappear in the perfectly conducting limit. When the flow is irrotational, boost invariant and with vanishing four-acceleration, the corresponding evolution equations are explicitly integrated so that the various physical regimes can be directly verified.

  12. Relativistic effects in chemistry

    SciTech Connect

    Yatsimirskii, K.B.

    1995-11-01

    Relativistic effects become apparent when the velocity of the electron is arbitrarily close to the speed of light (137 au) without actually attaining it (in heavy atoms of elements at the end of Mendeleev`s Periodic Table). At the orbital level, the relativistic effect is apparent in the radial contraction of penetrating s and p shells, expansion of nonpenetrating d and f shells, and the spin-orbit splitting of p-,d-, and f-shells. The appearance of a relativistic effect is indicated in the variation in the electronic configurations of the atoms in the Periodic Table, the appearance of new types of closed electron shells (6s{sub 1/2}{sup 2}, 6p{sub 1/2}{sup 2}, 7s{sub 1/2}{sup 2}, 5d{sub 3/2}{sup 4}), the stabilization of unstable oxidation states of heavy elements, the characteristic variation in the ionization enthalpies of heavy atoms, their electron affinity, hydration energies, redox potentials, and optical electronegativities. In the spectra of coordination compounds, a relativistic effect is observed when comparing the position of the charge transfer bands in analogous compounds, the parameters characterizing the ligand field strength (10Dq), the interatomic distances and angles in compounds of heavy elements. A relativistic effect is also apparent in the ability of heavy metals to form clusters and superclusters. Relativistic corrections also affect other properties of heavy metal compounds (force constants, dipole moments, biological activity, etc.).

  13. Relativistic viscoelastic fluid mechanics

    SciTech Connect

    Fukuma, Masafumi; Sakatani, Yuho

    2011-08-15

    A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.

  14. Relativistic viscoelastic fluid mechanics.

    PubMed

    Fukuma, Masafumi; Sakatani, Yuho

    2011-08-01

    A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.

  15. Incidental Diagnosis of Diffuse Intrinsic Pontine Glioma in Children

    PubMed Central

    Wright, K. D.; Sabin, N. D.; Cheuk, D.; McNall-Knapp, R. Y.; Shurtleff, S. A.; Gajjar, A.; Broniscer, A.

    2014-01-01

    Children with diffuse intrinsic pontine glioma (DIPG) have a short onset, rapidly progressive neurologic decline before diagnosis. Therefore, incidental diagnosis of such an aggressive cancer is counterintuitive, yet our experience shows DIPG may occur as part of a spectrum of incidentally diagnosed pediatric brain cancers. Although children with incidentally diagnosed DIPG may experience a longer survival, it remains a potentially deadly cancer despite treatment with radiotherapy. Histologic confirmation is warranted when feasible in such patients to confirm diagnosis. Moreover, recent advances in genome-wide analyses may suggest incidentally diagnosed DIPGs are biologically distinct from the majority of these cancers. PMID:25598012

  16. Indirect inversions

    NASA Astrophysics Data System (ADS)

    Sergienko, Olga

    2013-04-01

    Since Doug MacAyeal's pioneering studies of the ice-stream basal traction optimizations by control methods, inversions for unknown parameters (e.g., basal traction, accumulation patterns, etc) have become a hallmark of the present-day ice-sheet modeling. The common feature of such inversion exercises is a direct relationship between optimized parameters and observations used in the optimization procedure. For instance, in the standard optimization for basal traction by the control method, ice-stream surface velocities constitute the control data. The optimized basal traction parameters explicitly appear in the momentum equations for the ice-stream velocities (compared to the control data). The inversion for basal traction is carried out by minimization of the cost (or objective, misfit) function that includes the momentum equations facilitated by the Lagrange multipliers. Here, we build upon this idea, and demonstrate how to optimize for parameters indirectly related to observed data using a suite of nested constraints (like Russian dolls) with additional sets of Lagrange multipliers in the cost function. This method opens the opportunity to use data from a variety of sources and types (e.g., velocities, radar layers, surface elevation changes, etc.) in the same optimization process.

  17. 78 FR 18965 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-28

    ... on OCS leases in the Chukchi Sea, Alaska, during the 2014 open-water season (78 FR 12542). NMFS... whether to issue an IHA. NMFS refers the reader to the February 22, 2013, Federal Register notice (78 FR... Specified Activities; Taking Marine Mammals Incidental to an Exploration Drilling Program in the Chukchi...

  18. 78 FR 24731 - Taking Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to an...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-26

    ... Proposed IHA, initiating a 30- day public comment period, on February 22, 2013 (78 FR 12542). We then published a notice extending the comment period by 45 days on March 28, 2013 (78 FR 18965). On April 22... Specified Activities; Taking Marine Mammals Incidental to an Exploration Drilling Program in the Chukchi...

  19. 76 FR 4093 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-24

    ... comment periods in the Federal Register on April 19, 2010 (74 FR 20482) for the Beaufort Sea request and May 7, 2010 (74 FR 25730) for the Chukchi Sea request. On May 27, 2010, following the April 20, 2010... Specified Activities; Taking Marine Mammals Incidental to Exploration Drilling Programs in the Chukchi...

  20. 77 FR 12246 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-29

    ... mammals incidental to black abalone (Haliotis cracherodii) research surveys. The first of five IHAs for the specified activities was issued to VanBlaricom on September 23, 2003 (68 FR 57427; October 3, 2003); the most recent of these was issued on January 18, 2008 (73 FR 4841; January 28, 2008),...

  1. 75 FR 53672 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-01

    ..., humpback, and fin whales, and is not likely to adversely affect sperm, sei, or blue whales and Kemp's..., and is not likely to adversely affect sperm, sei, or blue whales. National Environmental Policy Act... incidental harassment authorization for this activity pursuant to section 101(a)(5)(D) of the MMPA (74...

  2. 75 FR 24906 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-06

    ...: North Atlantic right whale; blue whale; fin whale; sei whale; minke whale; humpback whale; killer whale..., the North Atlantic right, blue, fin, sei, humpback, and sperm whales are all listed as endangered... the ``Estimated Take by Incidental Harassment'' section). Blue and sperm whales are not commonly......

  3. 78 FR 79403 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-30

    ... proposal and preliminary determinations (78 FR 64918). The notice initiated a 30-day public comment period... incidental to these same proposed activities (77 FR 72327, December 5, 2012). That IHA expired on December 2... ADDRESSES) and the Notice of Proposed IHA (78 FR 64918, October 30, 2013). Community Structure...

  4. 77 FR 51773 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-27

    ... on monitoring of marine mammal reactions to rocket launches at Vandenberg Air Force Base. In those... Administration (NOAA), Commerce. ACTION: Notice; proposed incidental harassment authorization; request for... non-target species, if such an alternative action is chosen, during a proposed house mouse...

  5. 77 FR 67797 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-14

    ... Administration (NOAA), Commerce. ACTION: Notice; issuance of an incidental harassment authorization. SUMMARY: In... Federal Register on August 27, 2012 (77 FR 51773), requesting comments from the public on the proposed... may be found in NMFS' Federal Register notice (77 FR 51773, August 27, 2012) and a summary is...

  6. 77 FR 59211 - Marine Mammals; Incidental Take During Specified Activities; Proposed Incidental Harassment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-26

    ... (Level A harassment) for cetaceans (70 FR 1871, January 11, 2005). In the absence of data on which to... and ramp-up procedures would prevent Level A harassment and limit the number of incidental takes by... measures are thus expected to prevent any Level A harassment and to minimize Level B harassment. It...

  7. 77 FR 27283 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-09

    ...) for the onset of Level B harassment from pulsed sound sources. The Notice of Proposed IHA (76 FR 68974... harassment. Bowheads may engage in avoidance behavior preventing their exposure to these levels of sound, and...; issuance of an incidental harassment authorization. SUMMARY: In accordance with the Marine...

  8. 76 FR 69758 - Draft Environmental Assessment, Incidental Take Plan, and Application for an Incidental Take...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-09

    ... expertise among trappers and non-trappers that may provide other minimization and mitigation measures in... inform the decision making process. In the draft EA, we attempted to quantify the incidental take of non-target wildlife (species other than lynx) in traps. We are particularly interested in whether there...

  9. 78 FR 28411 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

    ... Mexico Inc. (Shell) for an Incidental Harassment Authorization (IHA) to take marine mammals, by... not limited to, migration, breathing, nursing, breeding, feeding, or sheltering . Summary of Request.... For example, at the Guerreo Negro Lagoon in Baja California, Mexico, which is one of the...

  10. Incidental Warthin Tumor on Pertechnetate Scintigraphy.

    PubMed

    Kulkarni, Mukta; Shetkar, Shubhangi; Joshi, Prathamesh; Kasaliwal, Sanket; Chaudhari, Shrikant

    2016-09-01

    A 30-year-old woman underwent Tc-pertechnetate scintigraphy for evaluation of thyrotoxicosis. The scintigraphy revealed hypervascular thyroid gland with markedly increased trapping function in both the lobes suggesting diagnosis of Graves disease. Incidentally, a hypervascular and pertechnetate avid focus was seen along the lateral margin of the right parotid gland. Pertechnetate avidity and site of uptake suggested possibility of Warthin tumor. Clinical examination and ultrasonography revealed a well-defined lesion in the superficial lobe of the right parotid gland favoring diagnosis of benign lesion. Postsurgery specimen confirmed diagnosis of Warthin tumor. PMID:27405035

  11. SAMPEX Relativistic Microbursts Observation

    NASA Astrophysics Data System (ADS)

    Liang, X.; Comess, M.; Smith, D. M.; Selesnick, R. S.; Sample, J. G.; Millan, R. M.

    2012-12-01

    Relativistic (>1 MeV) electron microburst precipitation is thought to account for significant relativistic electron loss. We present the statistical and spectral analysis of relativistic microbursts observed by the Proton/Electron Telescope (PET) on board the Solar Anomalous Magnetospheric Particle Explorer(SAMPEX) satellite from 1992 to 2004. Spectrally we find that microbursts are well fit by an exponential energy distribution in the 0.5-4 MeV range with a spectral e-folding energy of E0 < 375 keV. We also discuss the comparison of morning microbursts with events at midnight, which were first identified as microbursts by O'Brien et al. (2004). Finally, we compare the loss-rates due to microbursts and non-microburst precipitation during storm times and averaged over all times.

  12. Relativistic Weierstrass random walks.

    PubMed

    Saa, Alberto; Venegeroles, Roberto

    2010-08-01

    The Weierstrass random walk is a paradigmatic Markov chain giving rise to a Lévy-type superdiffusive behavior. It is well known that special relativity prevents the arbitrarily high velocities necessary to establish a superdiffusive behavior in any process occurring in Minkowski spacetime, implying, in particular, that any relativistic Markov chain describing spacetime phenomena must be essentially Gaussian. Here, we introduce a simple relativistic extension of the Weierstrass random walk and show that there must exist a transition time t{c} delimiting two qualitative distinct dynamical regimes: the (nonrelativistic) superdiffusive Lévy flights, for trelativistic) Gaussian diffusion, for t>t{c} . Implications of this crossover between different diffusion regimes are discussed for some explicit examples. The study of such an explicit and simple Markov chain can shed some light on several results obtained in much more involved contexts. PMID:20866862

  13. Relativistic Bursian diode equilibria

    SciTech Connect

    Ender, A. Y.; Kuznetsov, V. I.; Schamel, H.

    2011-03-15

    A comprehensive study of steady-states of a planar vacuum diode driven by a cold relativistic electron beam is presented. The emitter electric field as a characteristic function for their existence is evaluated in dependence of the diode length, the applied potential V, and the relativistic beam factor at injection {gamma}{sub 0}. It is used to classify the different branches of possible solutions, which encompass electron flows that are (i) transmitted through the diode completely, (ii) partially reflected from a virtual cathode (VC) either within the diode region or at the collector side, and (iii) reflected totally. As a byproduct, the V and {gamma}{sub 0} dependences of both bifurcation points of the minimum potential and of the transmitted current are obtained and the ultrarelativistic limit, {gamma}{sub 0}>>1, is performed. In this highly relativistic regime, the density of electrons appears to be constant across the diode region except for a small area around the VC.

  14. Relativistic Weierstrass random walks.

    PubMed

    Saa, Alberto; Venegeroles, Roberto

    2010-08-01

    The Weierstrass random walk is a paradigmatic Markov chain giving rise to a Lévy-type superdiffusive behavior. It is well known that special relativity prevents the arbitrarily high velocities necessary to establish a superdiffusive behavior in any process occurring in Minkowski spacetime, implying, in particular, that any relativistic Markov chain describing spacetime phenomena must be essentially Gaussian. Here, we introduce a simple relativistic extension of the Weierstrass random walk and show that there must exist a transition time t{c} delimiting two qualitative distinct dynamical regimes: the (nonrelativistic) superdiffusive Lévy flights, for trelativistic) Gaussian diffusion, for t>t{c} . Implications of this crossover between different diffusion regimes are discussed for some explicit examples. The study of such an explicit and simple Markov chain can shed some light on several results obtained in much more involved contexts.

  15. Perspective: relativistic effects.

    PubMed

    Autschbach, Jochen

    2012-04-21

    This perspective article discusses some broadly-known and some less broadly-known consequences of Einstein's special relativity in quantum chemistry, and provides a brief outline of the theoretical methods currently in use, along with a discussion of recent developments and selected applications. The treatment of the electron correlation problem in relativistic quantum chemistry methods, and expanding the reach of the available relativistic methods to calculate all kinds of energy derivative properties, in particular spectroscopic and magnetic properties, requires on-going efforts. PMID:22519307

  16. Relativistic nuclear dynamics

    SciTech Connect

    Coester, F.

    1985-01-01

    A review is presented of three distinct approaches to the construction of relativistic dynamical models: (1) Relativistic canonical quantum mechanics. (The Hilbert space of states is independent of the interactions, which are introduced by modifying the energy operator.) (2) Hilbert spaces of manifestly covariant wave functions. (The interactions modify the metric of the Hilbert space.) (3) Covariant Green functions. In each of the three approaches the focus is on the formulation of the two-body dynamics, and problems in the construction of the corresponding many-body dynamics are discussed briefly. 21 refs.

  17. Perspective: relativistic effects.

    PubMed

    Autschbach, Jochen

    2012-04-21

    This perspective article discusses some broadly-known and some less broadly-known consequences of Einstein's special relativity in quantum chemistry, and provides a brief outline of the theoretical methods currently in use, along with a discussion of recent developments and selected applications. The treatment of the electron correlation problem in relativistic quantum chemistry methods, and expanding the reach of the available relativistic methods to calculate all kinds of energy derivative properties, in particular spectroscopic and magnetic properties, requires on-going efforts.

  18. 20 CFR 202.14 - Service incidental to railroad transportation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Service incidental to railroad transportation. 202.14 Section 202.14 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT EMPLOYERS UNDER THE ACT § 202.14 Service incidental to railroad transportation....

  19. 20 CFR 202.14 - Service incidental to railroad transportation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Service incidental to railroad transportation. 202.14 Section 202.14 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT EMPLOYERS UNDER THE ACT § 202.14 Service incidental to railroad transportation....

  20. 20 CFR 202.14 - Service incidental to railroad transportation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Service incidental to railroad transportation. 202.14 Section 202.14 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT EMPLOYERS UNDER THE ACT § 202.14 Service incidental to railroad transportation....

  1. 20 CFR 202.14 - Service incidental to railroad transportation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Service incidental to railroad transportation. 202.14 Section 202.14 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT EMPLOYERS UNDER THE ACT § 202.14 Service incidental to railroad transportation....

  2. 29 CFR 793.12 - Related and incidental work.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Related and incidental work. 793.12 Section 793.12 Labor... POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS EXEMPTION OF CERTAIN RADIO AND TELEVISION... Requirements for Exemption § 793.12 Related and incidental work. An employee who is employed primarily in...

  3. 29 CFR 793.12 - Related and incidental work.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Related and incidental work. 793.12 Section 793.12 Labor... POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS EXEMPTION OF CERTAIN RADIO AND TELEVISION... Requirements for Exemption § 793.12 Related and incidental work. An employee who is employed primarily in...

  4. 29 CFR 793.12 - Related and incidental work.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Related and incidental work. 793.12 Section 793.12 Labor... POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS EXEMPTION OF CERTAIN RADIO AND TELEVISION... Requirements for Exemption § 793.12 Related and incidental work. An employee who is employed primarily in...

  5. 20 CFR 202.14 - Service incidental to railroad transportation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Service incidental to railroad transportation. 202.14 Section 202.14 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT EMPLOYERS UNDER THE ACT § 202.14 Service incidental to railroad transportation....

  6. 29 CFR 793.12 - Related and incidental work.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Related and incidental work. 793.12 Section 793.12 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL... Requirements for Exemption § 793.12 Related and incidental work. An employee who is employed primarily in...

  7. 29 CFR 793.12 - Related and incidental work.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Related and incidental work. 793.12 Section 793.12 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL... Requirements for Exemption § 793.12 Related and incidental work. An employee who is employed primarily in...

  8. Implications of an Incidental Pulmonary Arteriovenous Malformation

    PubMed Central

    Holden, Van K.; Shah, Nirav G.; Verceles, Avelino C.

    2016-01-01

    Introduction. Pulmonary arteriovenous malformations (PAVMs) have been associated with life-threatening complications, such as stroke and massive hemoptysis, thus posing significant morbidity if left untreated. We report a case of an incidental finding of a PAVM in a trauma patient newly recognized to have suspected hereditary hemorrhagic telangiectasia (HHT). Case Description. A 34-year-old man with a history of recurrent epistaxis presented with a sudden fall associated with seizure-like activity. Trauma imaging showed a large subdural hematoma and, incidentally, a serpiginous focus within the right upper lobe with a prominent feeding artery consistent with a PAVM. The patient was diagnosed with a simple PAVM related to possible or suspected HHT, an autosomal dominant trait with age-related penetrance. He underwent a pulmonary arteriography of the right upper and lower lobe with the use of a microcatheter system; however, the PAVM could not be visualized. Thus, he was managed medically. The patient was educated on the need for prophylactic antibiotics prior to dental procedures and surveillance imaging. Discussion. Our case highlights the importance of obtaining a complete past medical and family history in young patients with a history of recurrent epistaxis to elicit features of HHT. The diagnosis can be made clinically and directly affects family members, who would otherwise not receive appropriate screening. PMID:27027094

  9. Incidental Finding and Management of Mesenteric Fibromatosis

    PubMed Central

    Nicolas, Gregory; Kfoury, Tony; Shimlati, Rasha; Tohme, Maroon; Wakim, Raja

    2016-01-01

    Patient: Male, 45 Final Diagnosis: Mesenteric fibromatosis Symptoms: — Medication: — Clinical Procedure: Surgical removal of the mesenteric fibromatosis Specialty: Surgery Objective: Rare disease Background: Mesenteric fibromatosis, also known as mesenteric desmoids, is part of the clinical-pathologic spectrum of deep fibromatosis, which encompasses a group of benign fibro-proliferative processes that are locally aggressive and have the capacity to infiltrate or recur without metastasis. Case Report: Case of a 45-year-old man, with a history of hypertension and lung fibrosis, presenting for a left abdominal mass, which was found incidentally during his lung fibrosis imaging. He complained of constipation due to pressure upon his bowel leading to difficulty in defecation. Conclusions: Although there are many overlapping criteria between gastrointestinal stromal tumors and mesenteric fibromatosis, making it difficult to discriminate between the two, there are differences that are unique to mesenteric fibromatosis that should be noticed during the diagnosis. In this case, mesenteric fibromatosis was unusual as it is not associated with Gardner’s syndrome, desmoid tumors, nor familial adenomatous polyposis, but was an incidental finding. PMID:27279600

  10. Incidental statistical summary representation over time.

    PubMed

    Oriet, Chris; Hozempa, Kadie

    2016-01-01

    Information taken in by the human visual system allows individuals to form statistical representations of sets of items. One's knowledge of natural categories includes statistical information, such as average size of category members and the upper and lower boundaries of the set. Previous research suggests that when subjects attend to a particular dimension of a set of items presented over an extended duration, they quickly learn about the central tendency of the set. However, it is unclear whether such learning can occur incidentally, when subjects are not attending to the relevant dimension of the set. The present study explored whether subjects could reproduce global statistical properties of a set presented over an extended duration when oriented to task-irrelevant properties of the set. Subjects were tested for their memory of its mean, its smallest and largest exemplars, the direction of its skew, and the relative distribution of the items. Subjects were able to accurately recall the average size circle, as well as the upper and lower boundaries of a set of 4,200 circles displayed over an extended period. This suggests that even without intending to do so, they were encoding and updating a statistical summary representation of a task-irrelevant attribute of the circles over time. Such incidental encoding of statistical properties of sets is thus a plausible mechanism for establishing a representation of typicality in category membership. PMID:26830709

  11. 76 FR 41463 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-14

    ...NMFS has received an application from the University of Alaska Geophysics Institute (UAGI) for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to conducting a marine geophysical seismic survey in the Arctic Ocean during September- October 2011. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to......

  12. 78 FR 29705 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ... application from the U.S. Navy (Navy) for an Incidental Harassment Authorization (IHA) to take marine mammals....noaa.gov/pr/permits/incidental.htm . Supplemental documents provided by the U.S. Navy may be found at..., (301) 427-8401. SUPPLEMENTARY INFORMATION: Background Sections 101(a)(5)(A) and (D) of the MMPA (16...

  13. Relativistic impulse dynamics.

    PubMed

    Swanson, Stanley M

    2011-08-01

    Classical electrodynamics has some annoying rough edges. The self-energy of charges is infinite without a cutoff. The calculation of relativistic trajectories is difficult because of retardation and an average radiation reaction term. By reconceptuallizing electrodynamics in terms of exchanges of impulses rather than describing it by forces and potentials, we eliminate these problems. A fully relativistic theory using photonlike null impulses is developed. Numerical calculations for a two-body, one-impulse-in-transit model are discussed. A simple relationship between center-of-mass scattering angle and angular momentum was found. It reproduces the Rutherford cross section at low velocities and agrees with the leading term of relativistic distinguishable-particle quantum cross sections (Møller, Mott) when the distance of closest approach is larger than the Compton wavelength of the particle. Magnetism emerges as a consequence of viewing retarded and advanced interactions from the vantage point of an instantaneous radius vector. Radiation reaction becomes the local conservation of energy-momentum between the radiating particle and the emitted impulse. A net action is defined that could be used in developing quantum dynamics without potentials. A reinterpretation of Newton's laws extends them to relativistic motion.

  14. The Relativistic Rocket

    ERIC Educational Resources Information Center

    Antippa, Adel F.

    2009-01-01

    We solve the problem of the relativistic rocket by making use of the relation between Lorentzian and Galilean velocities, as well as the laws of superposition of successive collinear Lorentz boosts in the limit of infinitesimal boosts. The solution is conceptually simple, and technically straightforward, and provides an example of a powerful…

  15. Radiation from Relativistic Jets

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.; Mizuno, Y.; Hardee, P.; Sol, H.; Medvedev, M.; Zhang, B.; Nordlund, A.; Frederiksen, J. T.; Fishman, G. J.; Preece, R.

    2008-01-01

    Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations of relativistic electron-ion (electron-positron) jets injected into a stationary medium show that particle acceleration occurs within the downstream jet. In the presence of relativistic jets, instabilities such as the Buneman instability, other two-streaming instability, and the Weibel (filamentation) instability create collisionless shocks, which are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The 'jitter' radiation from deflected electrons in small-scale magnetic fields has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation, a case of diffusive synchrotron radiation, may be important to understand the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.

  16. Relativistic effects on plasma expansion

    SciTech Connect

    Benkhelifa, El-Amine; Djebli, Mourad

    2014-07-15

    The expansion of electron-ion plasma is studied through a fully relativistic multi-fluids plasma model which includes thermal pressure, ambipolar electrostatic potential, and internal energy conversion. Numerical investigation, based on quasi-neutral assumption, is performed for three different regimes: nonrelativistic, weakly relativistic, and relativistic. Ions' front in weakly relativistic regime exhibits spiky structure associated with a break-down of quasi-neutrality at the expanding front. In the relativistic regime, ion velocity is found to reach a saturation limit which occurs at earlier stages of the expansion. This limit is enhanced by higher electron velocity.

  17. Incidental emotions influence risk preference and outcome evaluation.

    PubMed

    Zhao, Ding; Gu, Ruolei; Tang, Ping; Yang, Qiwei; Luo, Yue-Jia

    2016-10-01

    Incidental emotions, which are irrelevant to the current decision, play a significant role in the decision-making process. In this study, to investigate the influence of incidental emotions on behavioral, psychological, and electrophysiological responses in the process of decision making, participants were required to perform a monetary gambling task. During the selection stage, an emotional picture, which was chosen from the Chinese Affective Picture System and fell into one of three categories: negative, neutral, and positive, was presented between two alternatives (small/large amount of bet). The pictures were provided to induce incidental emotions. ERPs and self-rating emotional experiences to outcome feedback were recorded during the task. Behavioral results showed that positive incidental emotions elicited risk preference, but emotional experiences to outcome feedback were not influenced by incidental emotions. The feedback-related negativity amplitudes were larger in the positive emotion condition than in the negative and neutral emotion conditions for small outcomes (including wins and losses), whereas there was no difference between the three conditions for large outcomes. In addition, the amplitudes of P3 were reduced overall in the negative emotion condition. We suggest that incidental emotions have modulated both the option assessment stage (manifested in behavioral choices) and the outcome evaluation stage (manifested in ERP amplitudes) of decision making unconsciously (indicated by unchanged subjective emotional experiences). The current findings have expanded our understanding of the role of incidental emotion in decision making.

  18. Incidental emotions influence risk preference and outcome evaluation.

    PubMed

    Zhao, Ding; Gu, Ruolei; Tang, Ping; Yang, Qiwei; Luo, Yue-Jia

    2016-10-01

    Incidental emotions, which are irrelevant to the current decision, play a significant role in the decision-making process. In this study, to investigate the influence of incidental emotions on behavioral, psychological, and electrophysiological responses in the process of decision making, participants were required to perform a monetary gambling task. During the selection stage, an emotional picture, which was chosen from the Chinese Affective Picture System and fell into one of three categories: negative, neutral, and positive, was presented between two alternatives (small/large amount of bet). The pictures were provided to induce incidental emotions. ERPs and self-rating emotional experiences to outcome feedback were recorded during the task. Behavioral results showed that positive incidental emotions elicited risk preference, but emotional experiences to outcome feedback were not influenced by incidental emotions. The feedback-related negativity amplitudes were larger in the positive emotion condition than in the negative and neutral emotion conditions for small outcomes (including wins and losses), whereas there was no difference between the three conditions for large outcomes. In addition, the amplitudes of P3 were reduced overall in the negative emotion condition. We suggest that incidental emotions have modulated both the option assessment stage (manifested in behavioral choices) and the outcome evaluation stage (manifested in ERP amplitudes) of decision making unconsciously (indicated by unchanged subjective emotional experiences). The current findings have expanded our understanding of the role of incidental emotion in decision making. PMID:27354122

  19. Properties of Doubly Heavy Baryons in the Relativistic Quark Model

    SciTech Connect

    Ebert, D.; Faustov, R.N.; Galkin, V.O.; Martynenko, A.P.

    2005-05-01

    Mass spectra and semileptonic decay rates of baryons consisting of two heavy (b or c) and one light quark are calculated in the framework of the relativistic quark model. The doubly heavy baryons are treated in the quark-diquark approximation. The ground and excited states of both the diquark and quark-diquark bound systems are considered. The quark-diquark potential is constructed. The light quark is treated completely relativistically, while the expansion in the inverse heavy-quark mass is used. The weak transition amplitudes of heavy diquarks bb and bc going, respectively, to bc and cc are explicitly expressed through the overlap integrals of the diquark wave functions in the whole accessible kinematic range. The relativistic baryon wave functions of the quark-diquark bound system are used for the calculation of the decay matrix elements, the Isgur-Wise function, and decay rates in the heavy-quark limit.

  20. Relevance of an incidental chest finding

    PubMed Central

    Cortés-Télles, Arturo; Mendoza, Daniel

    2012-01-01

    Solitary pulmonary nodule represents 0.2% of incidental findings in routine chest X-ray images. One of the main diagnoses includes lung cancer in which small-cell subtype has a poor survival rate. Recently, a new classification has been proposed including the very limited disease stage (VLD stage) or T1-T2N0M0 with better survival rate, specifically in those patients who are treated with surgery. However, current recommendations postulate that surgery remains controversial as a first-line treatment in this stage. We present the case of a 46-year-old female referred to our hospital with a preoperative diagnosis of a solitary pulmonary nodule. On initial approach, a biopsy revealed a small cell lung cancer. She received multimodal therapy with surgery, chemotherapy, and prophylactic cranial irradiation and is currently alive without recurrence on a 2-year follow-up. PMID:22345914

  1. 76 FR 79157 - Takes of Marine Mammals Incidental to Specified Activities; St. George Reef Light Station...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-21

    ...), for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment incidental to... SGRLPS to incidentally harass, by Level B harassment only, four species of marine mammals during the... Commerce to authorize, upon request, the incidental, but not intentional, taking by harassment of...

  2. Inverse Floatation

    NASA Astrophysics Data System (ADS)

    Nath, Saurabh; Mukherjee, Anish; Chatterjee, Souvick; Ganguly, Ranjan; Sen, Swarnendu; Mukhopadhyay, Achintya; Boreyko, Jonathan

    2014-11-01

    We have observed that capillarity forces may cause floatation in a few non-intuitive configurations. These may be divided into 2 categories: i) floatation of heavier liquid droplets on lighter immiscible ones and ii) fully submerged floatation of lighter liquid droplets in a heavier immiscible medium. We call these counter-intuitive because of the inverse floatation configuration. For case (i) we have identified and studied in detail the several factors affecting the shape and maximum volume of the floating drop. We used water and vegetable oil combinations as test fluids and established the relation between Bond Number and maximum volume contained in a floating drop (in the order of μL). For case (ii), we injected vegetable oil drop-wise into a pool of water. The fully submerged configuration of the drop is not stable and a slight perturbation to the system causes the droplet to burst and float in partially submerged condition. Temporal variation of a characteristic length of the droplet is analyzed using MATLAB image processing. The constraint of small Bond Number establishes the assumption of lubrication regime in the thin gap. A brief theoretical formulation also shows the temporal variation of the gap thickness. Jadavpur University, Jagadis Bose Centre of Excellence, Virginia Tech.

  3. Relativistic Pseudospin Symmetry

    SciTech Connect

    Ginocchio, Joseph N.

    2011-05-06

    We show that the pseudospin symmetry that Akito Arima discovered many years ago (with collaborators) is a symmetry of the the Dirac Hamiltonian for which the sum of the scalar and vector potentials are a constant. In this paper we discuss some of the implications of this relativistic symmetry and the experimental data that support these predictions. In his original paper Akito also discussed pseudo-U(3) symmetry. We show that pseudo-U(3) symmetry is a symmetry of the Dirac Hamiltonian for which the sum of harmonic oscillator vector and scalar potentials are equal to a constant, and we give the generators of pseudo-U(3) symmetry. Going beyond the mean field we summarize new results on non relativistic shell model Hamiltonians that have pseudospin symmetry and pseudo-orbital angular momentum symmetry as a dynamical symmetries.

  4. Relativistic multiwave Cerenkov generators

    SciTech Connect

    Bugaev, S.P.; Cherepenin, V.A.; Kanavets, V.I.; Klimov, A.I.; Kopenkin, A.D.; Koshelev, V.I.; Popov, V.A.; Slepkov, A.I. )

    1990-06-01

    A review of research on relativistic multiwave Cherenkov generators (MWCG) is provided. Presented is the linear theory of these devices, allowing a detailed description of multiwave interaction of a relativistic electron beam with an electromagnetic field in an electro-dynamic superdimensional MWCG system. The results of theoretical research on the starting parameters of generation, power flows, and the structure of the radiated field in a MWCG of a 3-cm-wave band are reported. The experiments on obtaining and investigating high-power pulses of microwave radiation in a MWCG of 3-cm- and 8-mm-wavelength bands are described. In particular, the results of research on a MWCG with the power of 15 GW in a 3-cm-wavelength band and the power of 3 GW in a 8-mm-wavelength band are presented. The results of research of spatial and temporal coherence of such generator radiation are reported.

  5. Relativistic shell model calculations

    NASA Astrophysics Data System (ADS)

    Furnstahl, R. J.

    1986-06-01

    Shell model calculations are discussed in the context of a relativistic model of nuclear structure based on renormalizable quantum field theories of mesons and baryons (quantum hadrodynamics). The relativistic Hartree approximation to the full field theory, with parameters determined from bulk properties of nuclear matter, predicts a shell structure in finite nuclei. Particle-hole excitations in finite nuclei are described in an RPA calculation based on this QHD ground state. The particle-hole interaction is prescribed by the Hartree ground state, with no additional parameters. Meson retardation is neglected in deriving the RPA equations, but it is found to have negligible effects on low-lying states. The full Dirac matrix structure is maintained throughout the calculation; no nonrelativistic reductions are made. Despite sensitive cancellations in the ground state calculation, reasonable excitation spectra are obtained for light nuclei. The effects of including charged mesons, problems with heavy nuclei, and prospects for improved and extended calculations are discussed.

  6. Relativistic electrons in space.

    NASA Technical Reports Server (NTRS)

    Simnett, G. M.

    1972-01-01

    This paper reviews the current state of knowledge concerning relativistic electrons, above 0.3 MeV, in interplanetary space, as measured by detectors on board satellites operating beyond the influence of the magnetosphere. The electrons have a galactic component, which at the lower energies is subject both to solar modulation and to spasmodic 'quiet time' increases and a direct solar component correlated with flare activity. The recent measurements have established the form of the differential energy spectrum of solar flare electrons. Electrons have been detected from flares behind the visible solar disk. Relativistic electrons do not appear to leave the sun at the time of the flash phase of the flare, although there are several signatures of electron acceleration at this time. The delay is interpreted as taking place during the transport of the electrons through the lower corona.

  7. Dielectric cavity relativistic magnetron

    NASA Astrophysics Data System (ADS)

    Hashemi, S. M. A.

    2010-02-01

    An alteration in the structure of the A6 relativistic magnetron is proposed, which introduces an extra degree of freedom to its design and enhances many of its quality factors. This modification involves the partial filling of the cavities of the device with a low-loss dielectric material. The operation of a dielectric-filled A6 is simulated; the results indicate single-mode operation at the desired π mode and a substantially cleaner rf spectrum.

  8. Relativistic tidal disruption events

    NASA Astrophysics Data System (ADS)

    Levan, A.

    2012-12-01

    In March 2011 Swift detected an extremely luminous and long-lived outburst from the nucleus of an otherwise quiescent, low luminosity (LMC-like) galaxy. Named Swift J1644+57, its combination of high-energy luminosity (1048 ergs s-1 at peak), rapid X-ray variability (factors of >100 on timescales of 100 seconds) and luminous, rising radio emission suggested that we were witnessing the birth of a moderately relativistic jet (Γ ˜ 2 - 5), created when a star is tidally disrupted by the supermassive black hole in the centre of the galaxy. A second event, Swift J2058+0516, detected two months later, with broadly similar properties lends further weight to this interpretation. Taken together this suggests that a fraction of tidal disruption events do indeed create relativistic outflows, demonstrates their detectability, and also implies that low mass galaxies can host massive black holes. Here, I briefly outline the observational properties of these relativistic tidal flares observed last year, and their evolution over the first year since their discovery.

  9. Point form relativistic quantum mechanics and relativistic SU(6)

    NASA Technical Reports Server (NTRS)

    Klink, W. H.

    1993-01-01

    The point form is used as a framework for formulating a relativistic quantum mechanics, with the mass operator carrying the interactions of underlying constituents. A symplectic Lie algebra of mass operators is introduced from which a relativistic harmonic oscillator mass operator is formed. Mass splittings within the degenerate harmonic oscillator levels arise from relativistically invariant spin-spin, spin-orbit, and tensor mass operators. Internal flavor (and color) symmetries are introduced which make it possible to formulate a relativistic SU(6) model of baryons (and mesons). Careful attention is paid to the permutation symmetry properties of the hadronic wave functions, which are written as polynomials in Bargmann spaces.

  10. Duskside relativistic electron precipitation

    NASA Astrophysics Data System (ADS)

    Lorentzen, Kirsten Ruth

    1999-10-01

    On August 20, 1996, a balloon-borne X-ray pinhole camera and a high resolution germanium X-ray spectrometer observed an intense X-ray event near Kiruna, Sweden, at 1835 MLT, on an L-shell of 5.8. This X-ray event consisted of seven bursts spaced 100-200 seconds apart, with smaller 10-20 second variations observed within individual bursts. The energy spectra of these bursts show the presence of X-rays with energies greater than 1 MeV, which are best accounted for by atmospheric bremsstrahlung from mono-energetic 1.7 MeV precipitating electrons. The X-ray imager observed no significant motion or small-scale spatial structure in the event, implying that the bursts were temporal in nature. Ultra- violet images from the Polar satellite and energetic particle data from the Los Alamos geosynchronous satellites show a small magnetospheric substorm onset about 24 minutes before the start of the relativistic precipitation event. Since the balloon was south of the auroral oval and there was no associated increase in relativistic electron flux at geosynchronous altitude, the event must be the result of some mechanism selectively precipitating ambient relativistic electrons from the radiation belts. The balloon X-ray observations are analyzed in a magnetospheric context, in order to determine which of several mechanisms for selective precipitation of relativistic electrons can account for the event. Resonance with electromagnetic ion cyclotron mode waves on the equator is the most likely candidate. The drift of substorm-injected warm protons is calculated using input from the geosynchronous satellites. Wave growth in the model is driven by temperature anisotropies in the warm proton population. A numerical solution of the wave dispersion relation shows that electromagnetic ion cyclotron waves can be excited in high-density duskside regions such as the plasmasphere or detached plasma regions. These waves can selectively precipitate relativistic electrons of energy 1.7 MeV in

  11. The Radiological Prevalence of Incidental Kienböck Disease

    PubMed Central

    Golay, Saroj K.; Rust, Philippa; Ring, David

    2016-01-01

    Background: To determine the prevalence of incidental Kienböck disease. Methods: A retrospective analysis of 150,912 radiological reports or images obtained over a five year period was performed of 76,174 patients who underwent a radiograph or computed tomography scan which included the wrist, in Edinburgh and Lothian, UK. Results: There were 5 cases of incidental Kienböck disease and 13 cases of symptomatic Kienböck disease. There were no significant differences in age, sex, ethnicity, comorbidities, smoking status, excess alcohol use or Lichtman stage between the incidental and symptomatic Kienböck groups. Conclusion: The radiological prevalence of incidental Kienböck disease was 0.0066% or 7 in 100,000 patients. PMID:27517065

  12. Self-Consistent Synchrotron Spectra from Trans-Relativistic Electron Acceleration

    NASA Astrophysics Data System (ADS)

    Becker, Peter A.

    2015-01-01

    Most existing analytical models describing the second-order Fermi acceleration of relativistic electrons due to collisions with MHD waves assume that the injected seed particles are already highly relativistic, despite the fact that the most prevalent source of particles is usually the non-relativistic thermal background gas. This presents a problem because the momentum dependence of the momentum diffusion coefficient describing the interaction between the electrons and the MHD waves is qualitatively different in the non-relativistic and highly relativistic limits. The lack of an analytical model has forced workers to rely on numerical simulations to obtain particle spectra describing the trans-relativistic case. In this work, we present the first analytical solution to the global, trans-relativistic problem of electron acceleration, obtained by using a hybrid form for the momentum diffusion coefficient, given by the sum of the two asymptotic forms. We refer to this process as "quasi hard-sphere scattering." The model also incorporates the appropriate momentum dependence for the particle escape timescale, and the effect of synchrotron and inverse-Compton losses, which are critical for establishing the location of the high-energy cutoff in the particle spectrum. Since synchrotron and inverse-Compton losses are included in the transport equation, the resulting radiation spectra are computed self-consistently. The results can be used to model the acceleration of radiating electrons in AGN and solar environments, applications of both types are discussed.

  13. Incidental Superior Hypophygeal Artery Aneurysm Embedded within Pituitary Adenoma

    PubMed Central

    Choi, Hong-Seok; Kim, Min-Su; Jung, Young-Jin

    2013-01-01

    Intra-cranial aneurysm can be incidental findings in patients with pituitary adenomas, and are usually located outside the pituitary region. However, the coexistence of intrasellar (not intracranial) aneurysms with pituitary adenomas is extremely rare. We report a patient with an incidental superior hypophygeal aneurysm embedded within a non-functional pituitary adenoma which was treated by transsphenoidal surgery after endovascular coil embolization. PMID:24278658

  14. Relativistic interactions and realistic applications

    SciTech Connect

    Hoch, T.; Madland, D.; Manakos, P.; Mannel, T.; Nikolaus, B.A.; Strottman, D. |

    1992-12-31

    A four-fermion-coupling Lagrangian (relativistic Skyrme-type) interaction has been proposed for relativistic nuclear structure calculations. This interaction, which has the merit of simplicity, is from the outset tailored as an effective interaction for relativistic Hartree-Fock calculations. Various extensions of such a model are discussed and compared with Walecka`s meson-nucleon mean field approach. We also present results of the calculation of nuclear ground state properties with an extended (density dependent) version of the four fermion interaction in a relativistic Hartree-Fock approximation.

  15. Incidental findings on MRI of the temporomandibular joint

    PubMed Central

    Makdissi, J; Pawar, R R; Radon, M; Holmes, S B

    2013-01-01

    Objectives: The aim of this study was to determine the prevalence of incidental findings in MRI of the temporomandibular joint (TMJ). Methods: MRI reports of 730 patients were assessed. The reports were analysed by one consultant and one clinical lecturer in dental and maxillofacial radiology. The prevalence of intracranial and extracranial incidental findings was recorded and categorized. Results: There were 53 (7.3%) incidental findings, of which 11 (1.5%) were intracranial and 42 (5.7%) were extracranial (divided into paranasal sinuses, mastoid air cells, muscle hypertrophy, lymphadenopathy and salivary glands). A total number of eight intracranial findings needed further dedicated imaging and/or specialist clinical opinion. Only one tumour (a meningioma) was found and required surgical intervention. Conclusions: Incidental findings on TMJ MRI are rare but not unheard of. The clinical relevance of incidental findings can be significant, and it is therefore important to ensure that the full data set of images is inspected, including any scout slices. A close working relationship between the areas of dental and maxillofacial radiology and neuroradiology is essential in expediting a second opinion relating to intracranial findings. All incidental findings should be communicated to referring clinicians in a timely manner, based on their urgency and clinical significance. PMID:24005059

  16. Incidental Diagnosis in Healthy Clinical Trial Subjects

    PubMed Central

    Duncan, Christopher JA; Rowland, Rosalind; Lillie, Patrick J; Meyer, Joel; Sheehy, Susanne H; O'Hara, Geraldine A; Hamill, Matthew; Donaldson, Hannah; Dinsmore, Laura; Poulton, Ian D; Gilbert, Sarah C; McShane, Helen; Hill, Adrian VS

    2012-01-01

    Previously unrecognized medical conditions identified in volunteers for early phase clinical studies have significant clinical and ethical implications for the participant. It is therefore crucial that the potential for unexpected diagnosis is addressed during the informed consent process. But the frequency of incidental diagnosis in healthy volunteers who attend for clinical trial screening remains unclear. To assess this we retrospectively analyzed 1,131 independent screening visits for 990 volunteers at a single academic center over a 10-year period to describe the frequency and nature of new clinical findings. Overall 23 of 990 volunteers (2.3%) were excluded at screening for a newly diagnosed medical abnormality. Some clinically important conditions, such as nephrotic syndrome and familial hypercholesterolemia were identified. The frequency of abnormalities was associated with increasing age in males (p = 0.02 χ2 for trend) but not females (p = 0.82). These data will assist those planning and conducting phase I/II vaccine trials in healthy volunteers, and importantly should strengthen the informed consent of future trial participants. Clin Trans Sci 2012; Volume 5: 348–350 PMID:22883613

  17. Incidental sounds of locomotion in animal cognition.

    PubMed

    Larsson, Matz

    2012-01-01

    The highly synchronized formations that characterize schooling in fish and the flight of certain bird groups have frequently been explained as reducing energy expenditure. I present an alternative, or complimentary, hypothesis that synchronization of group movements may improve hearing perception. Although incidental sounds produced as a by-product of locomotion (ISOL) will be an almost constant presence to most animals, the impact on perception and cognition has been little discussed. A consequence of ISOL may be masking of critical sound signals in the surroundings. Birds in flight may generate significant noise; some produce wing beats that are readily heard on the ground at some distance from the source. Synchronization of group movements might reduce auditory masking through periods of relative silence and facilitate auditory grouping processes. Respiratory locomotor coupling and intermittent flight may be other means of reducing masking and improving hearing perception. A distinct border between ISOL and communicative signals is difficult to delineate. ISOL seems to be used by schooling fish as an aid to staying in formation and avoiding collisions. Bird and bat flocks may use ISOL in an analogous way. ISOL and interaction with animal perception, cognition, and synchronized behavior provide an interesting area for future study. PMID:21748447

  18. Incidental sounds of locomotion in animal cognition.

    PubMed

    Larsson, Matz

    2012-01-01

    The highly synchronized formations that characterize schooling in fish and the flight of certain bird groups have frequently been explained as reducing energy expenditure. I present an alternative, or complimentary, hypothesis that synchronization of group movements may improve hearing perception. Although incidental sounds produced as a by-product of locomotion (ISOL) will be an almost constant presence to most animals, the impact on perception and cognition has been little discussed. A consequence of ISOL may be masking of critical sound signals in the surroundings. Birds in flight may generate significant noise; some produce wing beats that are readily heard on the ground at some distance from the source. Synchronization of group movements might reduce auditory masking through periods of relative silence and facilitate auditory grouping processes. Respiratory locomotor coupling and intermittent flight may be other means of reducing masking and improving hearing perception. A distinct border between ISOL and communicative signals is difficult to delineate. ISOL seems to be used by schooling fish as an aid to staying in formation and avoiding collisions. Bird and bat flocks may use ISOL in an analogous way. ISOL and interaction with animal perception, cognition, and synchronized behavior provide an interesting area for future study.

  19. Clinical approach to incidental pancreatic cysts

    PubMed Central

    Chiang, Austin L; Lee, Linda S

    2016-01-01

    The approach to incidentally noted pancreatic cysts is constantly evolving. While surgical resection is indicated for malignant or higher risk cysts, correctly identifying these highest risk pancreatic cystic lesions remains difficult. Using parameters including cyst size, presence of solid components, and pancreatic duct involvement, the 2012 International Association of Pancreatology (IAP) and the 2015 American Gastroenterological Association (AGA) guidelines have sought to identify the higher risk patients who would benefit from further evaluation using endoscopic ultrasound (EUS). Not only can EUS help further assess the presence of solid component and nodules, but also fine needle aspiration of cyst fluid aids in diagnosis by obtaining cellular, molecular, and genetic data. The impact of new endoscopic innovations with novel methods of direct visualization including confocal endomicroscopy require further validation. This review also highlights the differences between the 2012 IAP and 2015 AGA guidelines, which include the thresholds for sending patients for EUS and surgery and methods, interval, and duration of surveillance for unresected cysts. PMID:26811661

  20. Incidentally diagnosed pulmonary nodule: a diagnostic algorithm.

    PubMed

    Dziedzic, Robert; Rzyman, Witold

    2014-12-01

    Asymptomatic solitary pulmonary nodules incidentally revealed by computed tomography has become a serious medical problem. Depending on their diameter, solid, part-solid, or pure ground-glass pulmonary nodules may be observed, diagnosed radiologically/invasively, or resected in accordance with international guidelines. Pure ground-glass nodules, semi-solid lesions, or solid lesions smaller than 8 mm should be monitored by serial low-dose computed tomography. In the case of solid nodules greater than 8 mm, the assessment of the risk of malignancy is recommended. Patients at high risk of lung cancer with pulmonary lesions should undergo diagnostic investigation, or the nodule should be resected. If the risk of lung cancer is low, the patients may be monitored. Needle aspiration biopsy is the most important invasive method of tumor diagnosis. Cytological or histopathological diagnosis is helpful in appropriate clinical decision making that reduces the risk of unnecessary surgery, decreasing the rate of benign nodule resections and thus reducing the costs of medical treatment.

  1. The relativist stance.

    PubMed

    Rössler, O E; Matsuno, K

    1998-04-01

    The two mindsets of absolutism and relativism are juxtaposed, and the relational or relativist stance is vindicated. The only 'absolute' entity which undeniably exists, consciousness has the reality of a dream. The escape hatch from this prison is relational, as Descartes and Levinas found out: Unfalsified relational consistency implies exteriority. Exteriority implies infinite power which in turn makes compassion inevitable. Aside from ethics as a royal way to enlightenment, a new technology called 'deep technology' may be accessible. It changes the whole world in a demonstrable fashion by manipulation of the micro frame--that is, the observer-world interface.

  2. Relativistic quantum information

    NASA Astrophysics Data System (ADS)

    Mann, R. B.; Ralph, T. C.

    2012-11-01

    Over the past few years, a new field of high research intensity has emerged that blends together concepts from gravitational physics and quantum computing. Known as relativistic quantum information, or RQI, the field aims to understand the relationship between special and general relativity and quantum information. Since the original discoveries of Hawking radiation and the Unruh effect, it has been known that incorporating the concepts of quantum theory into relativistic settings can produce new and surprising effects. However it is only in recent years that it has become appreciated that the basic concepts involved in quantum information science undergo significant revision in relativistic settings, and that new phenomena arise when quantum entanglement is combined with relativity. A number of examples illustrate that point. Quantum teleportation fidelity is affected between observers in uniform relative acceleration. Entanglement is an observer-dependent property that is degraded from the perspective of accelerated observers moving in flat spacetime. Entanglement can also be extracted from the vacuum of relativistic quantum field theories, and used to distinguish peculiar motion from cosmological expansion. The new quantum information-theoretic framework of quantum channels in terms of completely positive maps and operator algebras now provides powerful tools for studying matters of causality and information flow in quantum field theory in curved spacetimes. This focus issue provides a sample of the state of the art in research in RQI. Some of the articles in this issue review the subject while others provide interesting new results that will stimulate further research. What makes the subject all the more exciting is that it is beginning to enter the stage at which actual experiments can be contemplated, and some of the articles appearing in this issue discuss some of these exciting new developments. The subject of RQI pulls together concepts and ideas from

  3. The relativist stance.

    PubMed

    Rössler, O E; Matsuno, K

    1998-04-01

    The two mindsets of absolutism and relativism are juxtaposed, and the relational or relativist stance is vindicated. The only 'absolute' entity which undeniably exists, consciousness has the reality of a dream. The escape hatch from this prison is relational, as Descartes and Levinas found out: Unfalsified relational consistency implies exteriority. Exteriority implies infinite power which in turn makes compassion inevitable. Aside from ethics as a royal way to enlightenment, a new technology called 'deep technology' may be accessible. It changes the whole world in a demonstrable fashion by manipulation of the micro frame--that is, the observer-world interface. PMID:9648695

  4. Modeling relativistic nuclear collisions.

    SciTech Connect

    Anderlik, C.; Magas, V.; Strottman, D.; Csernai, L. P.

    2001-01-01

    Modeling Ultra-Relativistic Heavy Ion Collisioiis at RHIC and LHC energies using a Multi Module Model is presented. The first Module is the Effective String Rope Model for the calculation of the initial stages of the reaction; the output of this module is used as the initial state for the subsequent one-fluid hydrodynainical calculation module. It is shown that such an initial state leads to the creation of the third flow component. The hydrodynamical evolution of the energy density distribution is presented for RHIC energies. The final module describing the Freeze Out; and Hadronization is also discussed.

  5. Relativistic Effects on Chemical Properties.

    ERIC Educational Resources Information Center

    McKelvey, Donald R.

    1983-01-01

    Discusses how anomalous chemical properties may be explained by considering relativistic effects. Traces development of the relativistic wave equation (Dirac equation) starting with the Borh treatment of the hydrogen atom and discusses major consequences of the Dirac equation. Suggests that these topics receive greater attention in the…

  6. A Simple Relativistic Bohr Atom

    ERIC Educational Resources Information Center

    Terzis, Andreas F.

    2008-01-01

    A simple concise relativistic modification of the standard Bohr model for hydrogen-like atoms with circular orbits is presented. As the derivation requires basic knowledge of classical and relativistic mechanics, it can be taught in standard courses in modern physics and introductory quantum mechanics. In addition, it can be shown in a class that…

  7. relline: Relativistic line profiles calculation

    NASA Astrophysics Data System (ADS)

    Dauser, Thomas

    2015-05-01

    relline calculates relativistic line profiles; it is compatible with the common X-ray data analysis software XSPEC (ascl:9910.005) and ISIS (ascl:1302.002). The two basic forms are an additive line model (RELLINE) and a convolution model to calculate relativistic smearing (RELCONV).

  8. Relativistic and nonrelativistic quarkonium models

    SciTech Connect

    Ono, S.

    1982-11-01

    We propose a quarkonium potential for the Klein-Gordon equation. The relativistic effects are small even for uu-bar and dd-bar systems because the introduction of a scalar constant potential in a Klein-Gordon equation allows a minimization of relativistic effects via cancellations in our model.

  9. Relativistic Continuum Shell Model

    NASA Astrophysics Data System (ADS)

    Grineviciute, Janina; Halderson, Dean

    2011-04-01

    The R-matrix formalism of Lane and Thomas has been extended to the relativistic case so that the many-coupled channels problem may be solved for systems in which binary breakup channels satisfy a relative Dirac equation. The formalism was previously applied to the relativistic impulse approximation RIA and now we applied it to Quantum Hadrodynamics QHD in the continuum Tamm-Dancoff approximation TDA with the classical meson fields replaced by one-meson exchange potentials. None of the published QHD parameters provide a decent fit to the 15 N + p elastic cross section. The deficiency is also evident in inability of the QHD parameters with the one meson exchange potentials to reproduce the QHD single particle energies. Results with alternate parameters sets are presented. A. M. Lane and R. G. Thomas, R-Matrix Theory of Nuclear Reactions, Reviews of Modern Physics, 30 (1958) 257

  10. Stationary relativistic jets

    NASA Astrophysics Data System (ADS)

    Komissarov, Serguei S.; Porth, Oliver; Lyutikov, Maxim

    2015-11-01

    In this paper we describe a simple numerical approach which allows to study the structure of steady-state axisymmetric relativistic jets using one-dimensional time-dependent simulations. It is based on the fact that for narrow jets with vz≈ c the steady-state equations of relativistic magnetohydrodynamics can be accurately approximated by the one-dimensional time-dependent equations after the substitution z=ct. Since only the time-dependent codes are now publicly available this is a valuable and efficient alternative to the development of a high-specialised code for the time-independent equations. The approach is also much cheaper and more robust compared to the relaxation method. We tested this technique against numerical and analytical solutions found in literature as well as solutions we obtained using the relaxation method and found it sufficiently accurate. In the process, we discovered the reason for the failure of the self-similar analytical model of the jet reconfinement in relatively flat atmospheres and elucidated the nature of radial oscillations of steady-state jets.

  11. A relativistic trolley paradox

    NASA Astrophysics Data System (ADS)

    Matvejev, Vadim N.; Matvejev, Oleg V.; Grøn, Ø.

    2016-06-01

    We present an apparent paradox within the special theory of relativity, involving a trolley with relativistic velocity and its rolling wheels. Two solutions are given, both making clear the physical reality of the Lorentz contraction, and that the distance on the rails between each time a specific point on the rim touches the rail is not equal to 2 π R , where R is the radius of the wheel, but 2 π R / √{ 1 - R 2 Ω 2 / c 2 } , where Ω is the angular velocity of the wheels. In one solution, the wheel radius is constant as the velocity of the trolley increases, and in the other the wheels contract in the radial direction. We also explain two surprising facts. First that the shape of a rolling wheel is elliptical in spite of the fact that the upper part of the wheel moves faster than the lower part, and thus is more Lorentz contracted, and second that a Lorentz contracted wheel with relativistic velocity rolls out a larger distance between two successive touches of a point of the wheel on the rails than the length of a circle with the same radius as the wheels.

  12. Relativistic harmonic oscillator revisited

    SciTech Connect

    Bars, Itzhak

    2009-02-15

    The familiar Fock space commonly used to describe the relativistic harmonic oscillator, for example, as part of string theory, is insufficient to describe all the states of the relativistic oscillator. We find that there are three different vacua leading to three disconnected Fock sectors, all constructed with the same creation-annihilation operators. These have different spacetime geometric properties as well as different algebraic symmetry properties or different quantum numbers. Two of these Fock spaces include negative norm ghosts (as in string theory), while the third one is completely free of ghosts. We discuss a gauge symmetry in a worldline theory approach that supplies appropriate constraints to remove all the ghosts from all Fock sectors of the single oscillator. The resulting ghost-free quantum spectrum in d+1 dimensions is then classified in unitary representations of the Lorentz group SO(d,1). Moreover, all states of the single oscillator put together make up a single infinite dimensional unitary representation of a hidden global symmetry SU(d,1), whose Casimir eigenvalues are computed. Possible applications of these new results in string theory and other areas of physics and mathematics are briefly mentioned.

  13. Relativistic Iron Line Fits

    NASA Astrophysics Data System (ADS)

    Fink, M.; Dauser, T.; Beuchert, T.; Jeffreson, S.; Tawabutr, J.; Wilms, J.; García, J.; Walton, D. J.

    2016-08-01

    The 6.4 keV Iron reflection line possesses strong diagnostic potential for AGN-systems. In the rare case of unobscured AGN, this line receives a contribution from the very center of the accretion flow close to the event horizon that is subject to strong relativistic effects. The shape of this line distortion can be used infer important parameters of the central accretion region, especially the black hole spin parameter a* and the accretion disk inclination i. We analyze several (nine?) bare AGN spectra from the sample of Walton et al. 2012 using high resolution spectra from the XMM and NuStar archives. The relativistic reflection is modeled using the RELXILL code (Dauser 20XX). The newest iteration of the RELXILL model also supports a lamp post geometry for the irradiation of the accretion disk. By combining these detailed models with the wide spectral range of NuStar and XMM/NuStar joint observations we can put tight constraints on the aforementioned parameters and we can constrain the height of the source h in a possible lamp post geometry.

  14. Relativistic fluid formulation and theory of intense relativistic electron beams

    SciTech Connect

    Siambis, J.G.

    1984-01-01

    A new general relativistic fluid formulation has been obtained for intense relativistic electron beams (IREB) with arbitrarily high relativistic mass factor ..gamma... This theory is valid for confined IREB equilibria such as those found inside high energy accelerators as well as in the pinched and ion-focused regimes of beam propagation in plasma channels. The new relativistic fluid formulation is based on the covariant relativistic fluid formulation of Newcomb with the parameter lambda identical to 1, in order to allow for realistic confined equilibria. The resulting equilibrium constraints require that the beam has a slow rotational velocity around its direction of propagation and that the off-diagonal thermal stress element, associated with these two directions of motion, be nonzero. The effective betatron oscillation frequency of the fluid elements of the beam is modified by the radial gradient and anisotropies in the thermal stress elements of the beam fluid. The wave equation, for sausage, hose and filamentation excitations on the relativistic fluid beam, is found to be formally identical to that obtained from the Vlasov equation approach, hence phase-mixing damping is a generic and self-consistent correlate of the new relativistic fluid formulation.

  15. A Structured approach to incidental take decision making

    USGS Publications Warehouse

    McGowan, Conor P.

    2013-01-01

    Decision making related to incidental take of endangered species under U.S. law lends itself well to a structured decision making approach. Incidental take is the permitted killing, harming, or harassing of a protected species under the law as long as that harm is incidental to an otherwise lawful activity and does not “reduce appreciably the probability of survival and recovery in the wild.” There has been inconsistency in the process used for determining incidental take allowances across species and across time for the same species, and structured decision making has been proposed to improve decision making. I use an example decision analysis to demonstrate the process and its applicability to incidental take decisions, even under significant demographic uncertainty and multiple, competing objectives. I define the example problem, present an objectives statement and a value function, use a simulation model to assess the consequences of a set of management actions, and evaluate the tradeoffs among the different actions. The approach results in transparent and repeatable decisions.

  16. A Structured Approach to Incidental Take Decision Making

    NASA Astrophysics Data System (ADS)

    McGowan, Conor P.

    2013-01-01

    Decision making related to incidental take of endangered species under U.S. law lends itself well to a structured decision making approach. Incidental take is the permitted killing, harming, or harassing of a protected species under the law as long as that harm is incidental to an otherwise lawful activity and does not "reduce appreciably the probability of survival and recovery in the wild." There has been inconsistency in the process used for determining incidental take allowances across species and across time for the same species, and structured decision making has been proposed to improve decision making. I use an example decision analysis to demonstrate the process and its applicability to incidental take decisions, even under significant demographic uncertainty and multiple, competing objectives. I define the example problem, present an objectives statement and a value function, use a simulation model to assess the consequences of a set of management actions, and evaluate the tradeoffs among the different actions. The approach results in transparent and repeatable decisions.

  17. Relativistic Quantum Cryptography

    NASA Astrophysics Data System (ADS)

    Jeffrey, Evan; Kwiat, Paul

    2006-03-01

    We present results from a relativistic quantum cryptography system which uses photon storage to avoid bit sifting, in principle doubling the useful key rate. Bob stores the photon he receives from Alice in an optical delay line until she sends him the classical basis information, allowing him to measure every photon in the correct basis. Accounting for loss in our 489-ns storage cavity, we achieve a 66% increase in the BB84 key rate. The same system could be used for even greater gains in either the six-state protocol or cryptography using a larger Hilbert space. We show that the security of this protocol is equivalent to standard BB84: assuming the quantum and classical signals are space-like separated, no eavesdropper bound by special relativity can access both simultaneously.

  18. Relativistic Runaway Electrons

    NASA Astrophysics Data System (ADS)

    Breizman, Boris

    2014-10-01

    This talk covers recent developments in the theory of runaway electrons in a tokamak with an emphasis on highly relativistic electrons produced via the avalanche mechanism. The rapidly growing population of runaway electrons can quickly replace a large part of the initial current carried by the bulk plasma electrons. The magnetic energy associated with this current is typically much greater than the particle kinetic energy. The current of a highly relativistic runaway beam is insensitive to the particle energy, which separates the description of the runaway current evolution from the description of the runaway energy spectrum. A strongly anisotropic distribution of fast electrons is generally prone to high-frequency kinetic instabilities that may cause beneficial enhancement of runaway energy losses. The relevant instabilities are in the frequency range of whistler waves and electron plasma waves. The instability thresholds reported in earlier work have been revised considerably to reflect strong dependence of collisional damping on the wave frequency and the role of plasma non-uniformity, including radial trapping of the excited waves in the plasma. The talk also includes a discussion of enhanced scattering of the runaways as well as the combined effect of enhanced scattering and synchrotron radiation. A noteworthy feature of the avalanche-produced runaway current is a self-sustained regime of marginal criticality: the inductive electric field has to be close to its critical value (representing avalanche threshold) at every location where the runaway current density is finite, and the current density should vanish at any point where the electric field drops below its critical value. This nonlinear Ohm's law enables complete description of the evolving current profile. Work supported by the U.S. Department of Energy Contract No. DEFG02-04ER54742 and by ITER contract ITER-CT-12-4300000273. The views and opinions expressed herein do not necessarily reflect those of

  19. 75 FR 20344 - Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Rocket Launches from...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-19

    ... Marine Mammals Incidental to Rocket Launches from Kodiak, AK AGENCY: National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Commerce. ACTION: Notice; Issuance of a Letter of... (Eumetopias jubatus) and Pacific harbor seals (Phoca vitulina richardsi) incidental to rocket launches...

  20. Some problems in relativistic thermodynamics

    SciTech Connect

    Veitsman, E. V.

    2007-11-15

    The relativistic equations of state for ideal and real gases, as well as for various interface regions, have been derived. These dependences help to eliminate some controversies in the relativistic thermodynamics based on the special theory of relativity. It is shown, in particular, that the temperature of system whose velocity tends to the velocity of light in vacuum varies in accordance with the Ott law T = T{sub 0}/{radical}1 - v{sup 2}/c{sup 2}. Relativistic dependences for heat and mass transfer, for Ohm's law, and for a viscous flow of a liquid have also been derived.

  1. Gamma-ray novae as probes of relativistic particle acceleration at non-relativistic shocks

    NASA Astrophysics Data System (ADS)

    Metzger, B. D.; Finzell, T.; Vurm, I.; Hascoët, R.; Beloborodov, A. M.; Chomiuk, L.

    2015-07-01

    The Fermi Large Area Telescope (LAT) discovery that classical novae produce ≳100 MeV gamma-rays establishes that shocks and relativistic particle acceleration are key features of these events. These shocks are likely to be radiative due to the high densities of the nova ejecta at early times coincident with the gamma-ray emission. Thermal X-rays radiated behind the shock are absorbed by neutral gas and reprocessed into optical emission, similar to Type IIn (interacting) supernovae. Gamma-rays are produced by collisions between relativistic protons with the nova ejecta (hadronic scenario) or inverse Compton/bremsstrahlung emission from relativistic electrons (leptonic scenario), where in both scenarios the efficiency for converting relativistic particle energy into LAT gamma-rays is at most a few tens of per cent. The measured ratio of gamma-ray and optical luminosities, Lγ/Lopt, thus sets a lower limit on the fraction of the shock power used to accelerate relativistic particles, ɛnth. The measured value of Lγ/Lopt for two classical novae, V1324 Sco and V339 Del, constrains ɛnth ≳ 10-2 and ≳10-3, respectively. Leptonic models for the gamma-ray emission are disfavoured given the low electron acceleration efficiency, ɛnth ˜ 10-4-10-3, inferred from observations of Galactic cosmic rays and particle-in-cell numerical simulations. A fraction fsh ≳ 100(ɛnth/0.01)-1 and ≳10(ɛnth/0.01)-1 per cent of the optical luminosity is powered by shocks in V1324 Sco and V339 Del, respectively. Such high fractions challenge standard models that instead attribute all nova optical emission to the direct outwards transport of thermal energy released near the white dwarf surface. We predict hard ˜10-100 keV X-ray emission coincident with the LAT emission, which should be detectable by NuSTAR or ASTRO-H, even at times when softer ≲10 keV emission is absorbed by neutral gas ahead of the shocks.

  2. 75 FR 81972 - Taking of Threatened or Endangered Marine Mammals Incidental to Commercial Fishing Operations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-29

    .... stock of Steller sea lions incidental to commercial fishing will have a negligible impact on these... lions, and Eastern U.S. Steller sea lions incidental to commercial fishing will have a negligible impact... Mammals Incidental to Commercial Fishing Operations; Issuance of Permit AGENCY: National Marine...

  3. 76 FR 61670 - Receipt of an Application for Incidental Take Permit (16230)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-05

    ... the conservation plan would allow for the incidental take of specified numbers of sea turtles... monitor, minimize, and mitigate the incidental take of ESA-listed sea turtles. The conservation plan... application is for the incidental take of ESA- listed adult and juvenile sea turtles associated with...

  4. 78 FR 1838 - Takes of Marine Mammals Incidental to Specified Activities; St. George Reef Light Station...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... ] (Society), for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment... Harassment Authorization to the Society to incidentally harass, by Level B harassment only, four species of... limited to harassment. We shall grant authorization for the incidental taking of small numbers of...

  5. 75 FR 80471 - Takes of Marine Mammals Incidental to Specified Activities; St. George Reef Light Station...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-22

    ...), for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment incidental to... incidentally harass, by Level B harassment only, four species of marine mammals during the specified activity... intentional, taking by harassment of small numbers of marine mammals of a species or population stock,...

  6. A Review of Effect of Different Tasks on Incidental Vocabulary Acquisition

    ERIC Educational Resources Information Center

    Liu, Chen L.

    2015-01-01

    Studies of incidental vocabulary acquisition in second language learning have got more and more attention both at home and abroad. By first introducing the definition and theoretical foundations of incidental vocabulary acquisition, this paper reviews empirical studies of effect of different tasks on incidental vocabulary acquisition and points…

  7. Relativistic spectra of bound fermions

    SciTech Connect

    Giachetti, Riccardo; Sorace, Emanuele

    2007-02-27

    A two fermion relativistic invariant wave equation is used for numerical calculations of the hyperfine shifts of the Positronium levels in a Breit interaction scheme. The results agree with known data up to the order {alpha}4.

  8. Simulating relativistic binaries with Whisky

    NASA Astrophysics Data System (ADS)

    Baiotti, L.

    We report about our first tests and results in simulating the last phase of the coalescence and the merger of binary relativistic stars. The simulations were performed using our code Whisky and mesh refinement through the Carpet driver.

  9. Relativistic Transformation of Solid Angle.

    ERIC Educational Resources Information Center

    McKinley, John M.

    1980-01-01

    Rederives the relativistic transformations of light intensity from compact sources (stars) to show where and how the transformation of a solid angle contributes. Discusses astrophysical and other applications of the transformations. (Author/CS)

  10. Conductivity of a relativistic plasma

    SciTech Connect

    Braams, B.J.; Karney, C.F.F.

    1989-03-01

    The collision operator for a relativistic plasma is reformulated in terms of an expansion in spherical harmonics. This formulation is used to calculate the electrical conductivity. 13 refs., 1 fig., 1 tab.

  11. Scattering in Relativistic Particle Mechanics.

    NASA Astrophysics Data System (ADS)

    de Bievre, Stephan

    The problem of direct interaction in relativistic particle mechanics has been extensively studied and a variety of models has been proposed avoiding the conclusions of the so-called no-interaction theorems. In this thesis we study scattering in the relativistic two-body problem. We use our results to analyse gauge invariance in Hamiltonian constraint models and the uniqueness of the symplectic structure in manifestly covariant relativistic particle mechanics. We first present a general geometric framework that underlies approaches to relativistic particle mechanics. This permits a model-independent and geometric definition of the notions of asymptotic completeness and of Moller and scattering operators. Subsequent analysis of these concepts divides into two parts. First, we study the kinematic properties of the scattering transformation, i.e. those properties that arise solely from the invariance of the theory under the Poincare group. We classify all canonical (symplectic) scattering transformations on the relativistic phase space for two free particles in terms of a single function of the two invariants of the theory. We show how this function is determined by the center of mass time delay and scattering angle and vice versa. The second part of our analysis of the relativistic two-body scattering problem is devoted to the dynamical properties of the scattering process. Hence, we turn to two approaches to relativistic particle mechanics: the Hamiltonian constraint models and the manifestly covariant formalism. Using general geometric arguments, we prove "gauge invariance" of the scattering transformation in the Todorov -Komar Hamiltonian constraint model. We conclude that the scattering cross sections of the Todorov-Komar models have the same angular dependence as their non-relativistic counterpart, irrespective of a choice of gauge. This limits the physical relevance of those models. We present a physically non -trivial Hamiltonian constraint model, starting from

  12. Inverse anticipating chaos synchronization.

    PubMed

    Shahverdiev, E M; Sivaprakasam, S; Shore, K A

    2002-07-01

    We derive conditions for achieving inverse anticipating synchronization where a driven time-delay chaotic system synchronizes to the inverse future state of the driver. The significance of inverse anticipating chaos in delineating synchronization regimes in time-delay systems is elucidated. The concept is extended to cascaded time-delay systems.

  13. Practical Relativistic Bit Commitment.

    PubMed

    Lunghi, T; Kaniewski, J; Bussières, F; Houlmann, R; Tomamichel, M; Wehner, S; Zbinden, H

    2015-07-17

    Bit commitment is a fundamental cryptographic primitive in which Alice wishes to commit a secret bit to Bob. Perfectly secure bit commitment between two mistrustful parties is impossible through an asynchronous exchange of quantum information. Perfect security is, however, possible when Alice and Bob each split into several agents exchanging classical information at times and locations suitably chosen to satisfy specific relativistic constraints. In this Letter we first revisit a previously proposed scheme [C. Crépeau et al., Lect. Notes Comput. Sci. 7073, 407 (2011)] that realizes bit commitment using only classical communication. We prove that the protocol is secure against quantum adversaries for a duration limited by the light-speed communication time between the locations of the agents. We then propose a novel multiround scheme based on finite-field arithmetic that extends the commitment time beyond this limit, and we prove its security against classical attacks. Finally, we present an implementation of these protocols using dedicated hardware and we demonstrate a 2 ms-long bit commitment over a distance of 131 km. By positioning the agents on antipodal points on the surface of Earth, the commitment time could possibly be extended to 212 ms.

  14. Effects of Animated Visuals on Incidental Learning and Motivation.

    ERIC Educational Resources Information Center

    Rieber, Lloyd P.

    This study examined the effects of animated presentations on intentional and incidental learning and the degree to which computer practice activities contained intrinsically motivating characteristics as measured by continuing motivation. A total of 70 fourth graders participated in an introductory lesson on Newton's laws of motion. Two levels of…

  15. Guidance of Spatial Attention by Incidental Learning and Endogenous Cuing

    ERIC Educational Resources Information Center

    Jiang, Yuhong V.; Swallow, Khena M.; Rosenbaum, Gail M.

    2013-01-01

    Our visual system is highly sensitive to regularities in the environment. Locations that were important in one's previous experience are often prioritized during search, even though observers may not be aware of the learning. In this study we characterized the guidance of spatial attention by incidental learning of a target's spatial probability,…

  16. Is Incidental Vocabulary Acquisition Feasible to EFL Learning?

    ERIC Educational Resources Information Center

    Luo, Jian-ping

    2013-01-01

    For learning English as a foreign language, the efficiency of the approach of incidental vocabulary acquisition depends on the word frequency and text coverage. However, the statistics of English corpus reveals that English is a language that has a large vocabulary size but a low word frequency as well as text coverage, which is obviously not in…

  17. Strategy Training: An Incidental Learning Model for CAI.

    ERIC Educational Resources Information Center

    Derry, Sharon J.

    Attempts to train learning strategies have not produced marked or lasting increases in academic IQ, probably because current training models fail to recognize the evolutionary nature of strategies acquisition. Empirical and theoretical evidence supports an incidental learning model, which engineers the instructional environment following study…

  18. Representations of an Incidental Learning Framework to Support Mobile Learning

    ERIC Educational Resources Information Center

    Scanlon, Eileen; Gaved, Mark; Jones, Ann; Kukulska-Hulme, Agnes; Paletta, Lucas; Dunwell, Ian

    2014-01-01

    This paper discusses how the particular features of mobile learning can be harnessed to provide new informal learning opportunities in relation to context aware and location based learning. The MASELTOV project is developing representations of an incidental learning framework to enable software developers and researchers to both design and analyse…

  19. Incidental Learning of Geospatial Concepts across Grade Levels: Map Overlay

    ERIC Educational Resources Information Center

    Battersby, Sarah E.; Golledge, Reginald G.; Marsh, Meredith J.

    2006-01-01

    In this paper, the authors evaluate map overlay, a concept central to geospatial thinking, to determine how it is naively and technically understood, as well as to identify when it is leaner innately. The evaluation is supported by results from studies at three grade levels to show the progression of incidentally learned geospatial knowledge as…

  20. An Analysis of Adult Interaction Styles and Children's Incidental Imitation.

    ERIC Educational Resources Information Center

    Sharkey, Robert W.; Morris, Edward K.

    This paper describes two experiments designed to determine whether traditional effects of adult nurturance on children's incidental imitation could be obtained using a within-subject design and a functional (rather than operational) definition of nurturance. Four preschool children served as subjects, with four others serving as cross-sex…

  1. Incidental Vocabulary Acquisition from Reading an Authentic Text

    ERIC Educational Resources Information Center

    Daskalovska, Nina

    2014-01-01

    A number of studies have demonstrated that second/foreign language learners can acquire vocabulary from reading. This study was designed to examine whether advanced EFL learners can acquire vocabulary incidentally from reading an authentic text. Eighteen first year English major students read and listened to the first eight chapters of Pride and…

  2. Reviewing Theory and Research on Informal and Incidental Learning

    ERIC Educational Resources Information Center

    Marsick, Victoria J.; Watkins, Karen E.; Callahan, Mary Wilson; Volpe, Marie

    2006-01-01

    Leaders and employees of today's organizations typically assume increasing responsibility for their own and their organization's learning. Much of that learning is informal or incidental. This article reviews theory and research to update that model and identify future research challenges. Through this review, groundwork will be laid for…

  3. Concurrent Movement Impairs Incidental but Not Intentional Statistical Learning

    ERIC Educational Resources Information Center

    Stevens, David J.; Arciuli, Joanne; Anderson, David I.

    2015-01-01

    The effect of concurrent movement on incidental versus intentional statistical learning was examined in two experiments. In Experiment 1, participants learned the statistical regularities embedded within familiarization stimuli implicitly, whereas in Experiment 2 they were made aware of the embedded regularities and were instructed explicitly to…

  4. 75 FR 42121 - Marine Mammals; Incidental Take During Specified Activities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-20

    ... sea otters are listed as threatened under the ESA (42 FR 2965; January 14, 1977) and, because of their... applicant to incidentally take, by harassment, small numbers of southern sea otters for a period of 6 months... does not apply to southern sea otters. Section 101(a)(5)(D) of the MMPA established an...

  5. Incidental Language Learning in Foreign Language Content Courses

    ERIC Educational Resources Information Center

    Rodgers, Daryl M.

    2015-01-01

    This study examined the extent to which 40 students enrolled in upper level foreign language literary/cultural studies content courses showed evidence of incidental language learning over the course of a semester. Students completed a cloze passage and provided both writing and speaking samples at the beginning and end of the semester. In…

  6. Playground Exploration: An Opportunity for Incidental Learning of Mechanical Principles

    ERIC Educational Resources Information Center

    Lyons, Brian

    2005-01-01

    Play involves unstructured activity that is freely entered into and intrinsically rewarding. When children engage in play there is little intentional learning. There are no lesson plans. There are no daily objectives or specific learning outcomes. Incidental learning can cause relatively permanent changes in the way one thinks; accidental learning…

  7. Refining a relativistic, hydrodynamic solver: Admitting ultra-relativistic flows

    NASA Astrophysics Data System (ADS)

    Bernstein, J. P.; Hughes, P. A.

    2009-09-01

    We have undertaken the simulation of hydrodynamic flows with bulk Lorentz factors in the range 102-106. We discuss the application of an existing relativistic, hydrodynamic primitive variable recovery algorithm to a study of pulsar winds, and, in particular, the refinement made to admit such ultra-relativistic flows. We show that an iterative quartic root finder breaks down for Lorentz factors above 102 and employ an analytic root finder as a solution. We find that the former, which is known to be robust for Lorentz factors up to at least 50, offers a 24% speed advantage. We demonstrate the existence of a simple diagnostic allowing for a hybrid primitives recovery algorithm that includes an automatic, real-time toggle between the iterative and analytical methods. We further determine the accuracy of the iterative and hybrid algorithms for a comprehensive selection of input parameters and demonstrate the latter’s capability to elucidate the internal structure of ultra-relativistic plasmas. In particular, we discuss simulations showing that the interaction of a light, ultra-relativistic pulsar wind with a slow, dense ambient medium can give rise to asymmetry reminiscent of the Guitar nebula leading to the formation of a relativistic backflow harboring a series of internal shockwaves. The shockwaves provide thermalized energy that is available for the continued inflation of the PWN bubble. In turn, the bubble enhances the asymmetry, thereby providing positive feedback to the backflow.

  8. Nonthermal Particle Acceleration and Radiation in Relativistic Magnetic Reconnection

    NASA Astrophysics Data System (ADS)

    Werner, Gregory

    2015-11-01

    Many spectacular and violent phenomena in the high-energy universe exhibit nonthermal radiation spectra, from which we infer power-law energy distributions of the radiating particles. Relativistic magnetic reconnection, recognized as a leading mechanism of nonthermal particle acceleration, can efficiently transfer magnetic energy to energetic particles. We present a comprehensive particle-in-cell study of particle acceleration in 2D relativistic reconnection in both electron-ion and pair plasmas without guide field. We map out the power-law index α and the high-energy cutoff of the electron energy spectrum as functions of three key parameters: the system size (and initial layer length) L, the ambient plasma magnetization σ, and the ion/electron mass ratio (from 1 to 1836). We identify the transition between small- and large-system regimes: for small L, the system size affects the slope and extent of the high-energy spectrum, while for large enough L, α and the cutoff energy are independent of L. We compare high energy particle spectra and radiative (synchrotron and inverse Compton) signatures of the electrons, for pair and electron-ion reconnection. The latter cases maintain highly relativistic electrons, but include a range of different magnetizations yielding sub- to highly-relativistic ions. Finally, we show how nonthermal acceleration and radiative signatures alter when the radiation back-reaction becomes important. These results have important implications for assessing the promise and the limitations of relativistic reconnection as an astrophysically-important particle acceleration mechanism. This work is funded by NSF, DOE, and NASA.

  9. 78 FR 42508 - Notice of Availability of Draft Environmental Assessment on the Effects of Issuing an Incidental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-16

    ..., minimize, and mitigate the incidental take of ESA-listed sea turtles. The conservation plan includes... incidental take of threatened and endangered sea turtles during management of North Carolina inshore gillnet... incidental take permits (ITP's) to NCDMF for the incidental take of sea turtles in inshore gillnet...

  10. 77 FR 39485 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ..., 2008 (73 FR 34875), and remain in effect through July 19, 2013. For detailed information on this action.... Under the MMPA, the term ``take'' means to harass, hunt, capture, or kill or to attempt to harass, hunt, capture, or kill any marine mammal. Authorization for incidental taking, in the form of annual LOAs,...

  11. 77 FR 45341 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-31

    ..., 2008 (73 FR 34875), and remain in effect through July 19, 2013. For detailed information on this action... issued. Under the MMPA, the term ``take'' means to harass, hunt, capture, or kill or to attempt to harass, hunt, capture, or kill any marine mammal. Authorization for incidental taking, in the form of...

  12. 78 FR 22517 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-16

    ..., 2008 (73 FR 34875), and remain in effect through July 19, 2013. For detailed information on this action... the MMPA, the term ``take'' means to harass, hunt, capture, or kill or to attempt to harass, hunt, capture, or kill any marine mammal. Authorization for incidental taking, in the form of annual LOAs,...

  13. 78 FR 30273 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

    ... potential area of effect for this project (London, 2006; see Figure 4-1 of the Navy's application.... waters and just south of the U.S.-Mexico border, and animals belonging to this population may be found... application from the U.S. Navy (Navy) for an Incidental Harassment Authorization (IHA) to take marine...

  14. 76 FR 12070 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-04

    ... EROS were published on June 19, 2008 (73 FR 34875), and remain in effect through July 19, 2013. For... of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico... removal of offshore oil and gas structures (EROS) in the Gulf of Mexico. DATES: These authorizations...

  15. 78 FR 56659 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-13

    ... U.S. waters and just south of the U.S.-Mexico border, and animals belonging to this population may... from the U.S. Navy (Navy) for authorization to take marine mammals incidental to construction..., NMFS, (301) 427-8401. SUPPLEMENTARY INFORMATION: Availability A copy of the Navy's application and...

  16. On General Relativistic Uniformly Rotating White Dwarfs

    NASA Astrophysics Data System (ADS)

    Boshkayev, Kuantay; Rueda, Jorge A.; Ruffini, Remo; Siutsou, Ivan

    2013-01-01

    The properties of uniformly rotating white dwarfs (RWDs) are analyzed within the framework of general relativity. Hartle's formalism is applied to construct the internal and external solutions to the Einstein equations. The white dwarf (WD) matter is described by the relativistic Feynman-Metropolis-Teller equation of state which generalizes that of Salpeter by taking into account the finite size of the nuclei, and the Coulomb interactions as well as electroweak equilibrium in a self-consistent relativistic fashion. The mass M, radius R, angular momentum J, eccentricity epsilon, and quadrupole moment Q of RWDs are calculated as a function of the central density ρ c and rotation angular velocity Ω. We construct the region of stability of RWDs (J-M plane) taking into account the mass-shedding limit, inverse β-decay instability, and the boundary established by the turning points of constant J sequences which separates stable from secularly unstable configurations. We found the minimum rotation periods ~0.3, 0.5, 0.7, and 2.2 s and maximum masses ~1.500, 1.474, 1.467, 1.202 M ⊙ for 4He, 12C, 16O, and 56Fe WDs, respectively. By using the turning-point method, we found that RWDs can indeed be axisymmetrically unstable and we give the range of WD parameters where this occurs. We also construct constant rest-mass evolution tracks of RWDs at fixed chemical composition and show that, by losing angular momentum, sub-Chandrasekhar RWDs (mass smaller than maximum static one) can experience both spin-up and spin-down epochs depending on their initial mass and rotation period, while super-Chandrasekhar RWDs (mass larger than maximum static one) only spin up.

  17. ON GENERAL RELATIVISTIC UNIFORMLY ROTATING WHITE DWARFS

    SciTech Connect

    Boshkayev, Kuantay; Rueda, Jorge A.; Ruffini, Remo; Siutsou, Ivan E-mail: jorge.rueda@icra.it E-mail: siutsou@icranet.org

    2013-01-10

    The properties of uniformly rotating white dwarfs (RWDs) are analyzed within the framework of general relativity. Hartle's formalism is applied to construct the internal and external solutions to the Einstein equations. The white dwarf (WD) matter is described by the relativistic Feynman-Metropolis-Teller equation of state which generalizes that of Salpeter by taking into account the finite size of the nuclei, and the Coulomb interactions as well as electroweak equilibrium in a self-consistent relativistic fashion. The mass M, radius R, angular momentum J, eccentricity {epsilon}, and quadrupole moment Q of RWDs are calculated as a function of the central density {rho} {sub c} and rotation angular velocity {Omega}. We construct the region of stability of RWDs (J-M plane) taking into account the mass-shedding limit, inverse {beta}-decay instability, and the boundary established by the turning points of constant J sequences which separates stable from secularly unstable configurations. We found the minimum rotation periods {approx}0.3, 0.5, 0.7, and 2.2 s and maximum masses {approx}1.500, 1.474, 1.467, 1.202 M {sub Sun} for {sup 4}He, {sup 12}C, {sup 16}O, and {sup 56}Fe WDs, respectively. By using the turning-point method, we found that RWDs can indeed be axisymmetrically unstable and we give the range of WD parameters where this occurs. We also construct constant rest-mass evolution tracks of RWDs at fixed chemical composition and show that, by losing angular momentum, sub-Chandrasekhar RWDs (mass smaller than maximum static one) can experience both spin-up and spin-down epochs depending on their initial mass and rotation period, while super-Chandrasekhar RWDs (mass larger than maximum static one) only spin up.

  18. Shielding of relativistic protons.

    PubMed

    Bertucci, A; Durante, M; Gialanella, G; Grossi, G; Manti, L; Pugliese, M; Scampoli, P; Mancusi, D; Sihver, L; Rusek, A

    2007-06-01

    Protons are the most abundant element in the galactic cosmic radiation, and the energy spectrum peaks around 1 GeV. Shielding of relativistic protons is therefore a key problem in the radiation protection strategy of crewmembers involved in long-term missions in deep space. Hydrogen ions were accelerated up to 1 GeV at the NASA Space Radiation Laboratory, Brookhaven National Laboratory, New York. The proton beam was also shielded with thick (about 20 g/cm2) blocks of lucite (PMMA) or aluminium (Al). We found that the dose rate was increased 40-60% by the shielding and decreased as a function of the distance along the axis. Simulations using the General-Purpose Particle and Heavy-Ion Transport code System (PHITS) show that the dose increase is mostly caused by secondary protons emitted by the target. The modified radiation field after the shield has been characterized for its biological effectiveness by measuring chromosomal aberrations in human peripheral blood lymphocytes exposed just behind the shield block, or to the direct beam, in the dose range 0.5-3 Gy. Notwithstanding the increased dose per incident proton, the fraction of aberrant cells at the same dose in the sample position was not significantly modified by the shield. The PHITS code simulations show that, albeit secondary protons are slower than incident nuclei, the LET spectrum is still contained in the low-LET range (<10 keV/microm), which explains the approximately unitary value measured for the relative biological effectiveness. PMID:17256178

  19. Relativistic breakdown in planetary atmospheres

    SciTech Connect

    Dwyer, J. R.

    2007-04-15

    In 2003, a new electrical breakdown mechanism involving the production of runaway avalanches by positive feedback from runaway positrons and energetic photons was introduced. This mechanism, which shall be referred to as 'relativistic feedback', allows runaway discharges in gases to become self-sustaining, dramatically increasing the flux of runaway electrons, the accompanying high-energy radiation, and resulting ionization. Using detailed Monte Carlo calculations, properties of relativistic feedback are investigated. It is found that once relativistic feedback fully commences, electrical breakdown will occur and the ambient electric field, extending over cubic kilometers, will be discharged in as little as 2x10{sup -5} s. Furthermore, it is found that the flux of energetic electrons and x rays generated by this mechanism can exceed the flux generated by the standard relativistic runaway electron model by a factor of 10{sup 13}, making relativistic feedback a good candidate for explaining terrestrial gamma-ray flashes and other high-energy phenomena observed in the Earth's atmosphere.

  20. Polyanalytic relativistic second Bargmann transforms

    SciTech Connect

    Mouayn, Zouhaïr

    2015-05-15

    We construct coherent states through special superpositions of eigenstates of the relativistic isotonic oscillator. In each superposition, the coefficients are chosen to be L{sup 2}-eigenfunctions of a σ-weight Maass Laplacian on the Poincaré disk, which are associated with the eigenvalue 4m(σ−1−m), m∈Z{sub +}∩[0,(σ−1)/2]. For each nonzero m, the associated coherent states transform constitutes the m-true-polyanalytic extension of a relativistic version of the second Bargmann transform, whose integral kernel is expressed in terms of a special Appel-Kampé de Fériet’s hypergeometric function. The obtained results could be used to extend the known semi-classical analysis of quantum dynamics of the relativistic isotonic oscillator.

  1. Fluctuations in relativistic causal hydrodynamics

    NASA Astrophysics Data System (ADS)

    Kumar, Avdhesh; Bhatt, Jitesh R.; Mishra, Ananta P.

    2014-05-01

    Formalism to calculate the hydrodynamic fluctuations by applying the Onsager theory to the relativistic Navier-Stokes equation is already known. In this work, we calculate hydrodynamic fluctuations within the framework of the second order hydrodynamics of Müller, Israel and Stewart and its generalization to the third order. We have also calculated the fluctuations for several other causal hydrodynamical equations. We show that the form for the Onsager-coefficients and form of the correlation functions remain the same as those obtained by the relativistic Navier-Stokes equation and do not depend on any specific model of hydrodynamics. Further we numerically investigate evolution of the correlation function using the one dimensional boost-invariant (Bjorken) flow. We compare the correlation functions obtained using the causal hydrodynamics with the correlation function for the relativistic Navier-Stokes equation. We find that the qualitative behavior of the correlation functions remains the same for all the models of the causal hydrodynamics.

  2. Toward a relativistic gas dynamics

    SciTech Connect

    Solovev, L.S.

    1982-01-01

    Macroscopic gas dynamics on the basis of general-relativity equations is examined. An additional equation is derived which provides for completeness of the system of relativistic gasdynamic equations. Relativistic equations of two-fluid electromagnetic gas dynamics are obtained. The introduction of appropriate energy-momentum tensors makes it possible to allow for dissipative processes conditioned by viscosity, thermal conductivity, radiative thermal conductivity, ohmic resistance, and ion-electron temperature difference. The problem of generalizing the Friedmann cosmological model in the case of particle production and annihilation is considered. Also, considered are gas equilibrium in a spherically symmetric gravitational field and a two-fluid relativistic stream in an intrinsic electromagnetic field. 16 references.

  3. The friendly incidental portal vein thrombus in liver transplantation.

    PubMed

    Koh, Peng Soon; Chan, See Ching; Chok, Kenneth Siu-Ho; Sharr, William Wei; Wong, Tiffany Cho-Lam; Sin, Sui Ling; Lo, Chung Mau

    2015-07-01

    Improved outcomes have been shown in liver transplantation (LT) with portal vein thrombosis (PVT). However, PVT is still discovered incidentally during surgery despite careful preoperative imaging. Data are limited comparing the outcomes of incidental PVT with PVT diagnosed via preoperative imaging before LT. This study aims to compare the overall outcomes of patients with PVT. From 2008 to 2012, 369 patients had LT, and 58 patients with PVT were identified. They were divided into those with non-PVT (group 0; n = 311), preoperatively identified PVT (group 1; n = 28), and incidental PVT (group 2; n = 30). The demographics, characteristics, preoperative assessment, and postoperative outcomes were compared. A survival analysis was also performed. Baseline characteristics and preoperative evaluations of all 3 groups were comparable (P > 0.05) except for Model for End-Stage Liver Disease score, tumor status, platelet levels, and serum bilirubin. A multivariate analysis only showed a high serum bilirubin level to be a predictor of PVT (P = 0.004; odds ratio, 3.395; 95% confidence interval, 1.467-7.861). Postoperative outcomes were also comparable (P > 0.05). Compared to group 2, group 1 had more patients with a Yerdel classification of 3 or 4 with more extensive surgical intervention required (P = 0.02). The survival analysis in all 3 groups was comparable with 5-year survival rate of 87.4%, 84.6%, and 91.8% in group 0, 1, and 2, respectively (P = 0.66). In conclusion, recipients with PVT undergoing LT can have similar outcomes as the non-PVT patients even if PVTs were discovered incidentally. Discovery of incidental PVT only requires thrombectomy with no substantial change of treatment strategy, and the outcome is not adversely affected because most incidental PVTs are of a lower Yerdel grade. Preoperative imaging is useful to identify those with a higher Yerdel grade to allow planning of surgical strategy during transplantation.

  4. The friendly incidental portal vein thrombus in liver transplantation.

    PubMed

    Koh, Peng Soon; Chan, See Ching; Chok, Kenneth Siu-Ho; Sharr, William Wei; Wong, Tiffany Cho-Lam; Sin, Sui Ling; Lo, Chung Mau

    2015-07-01

    Improved outcomes have been shown in liver transplantation (LT) with portal vein thrombosis (PVT). However, PVT is still discovered incidentally during surgery despite careful preoperative imaging. Data are limited comparing the outcomes of incidental PVT with PVT diagnosed via preoperative imaging before LT. This study aims to compare the overall outcomes of patients with PVT. From 2008 to 2012, 369 patients had LT, and 58 patients with PVT were identified. They were divided into those with non-PVT (group 0; n = 311), preoperatively identified PVT (group 1; n = 28), and incidental PVT (group 2; n = 30). The demographics, characteristics, preoperative assessment, and postoperative outcomes were compared. A survival analysis was also performed. Baseline characteristics and preoperative evaluations of all 3 groups were comparable (P > 0.05) except for Model for End-Stage Liver Disease score, tumor status, platelet levels, and serum bilirubin. A multivariate analysis only showed a high serum bilirubin level to be a predictor of PVT (P = 0.004; odds ratio, 3.395; 95% confidence interval, 1.467-7.861). Postoperative outcomes were also comparable (P > 0.05). Compared to group 2, group 1 had more patients with a Yerdel classification of 3 or 4 with more extensive surgical intervention required (P = 0.02). The survival analysis in all 3 groups was comparable with 5-year survival rate of 87.4%, 84.6%, and 91.8% in group 0, 1, and 2, respectively (P = 0.66). In conclusion, recipients with PVT undergoing LT can have similar outcomes as the non-PVT patients even if PVTs were discovered incidentally. Discovery of incidental PVT only requires thrombectomy with no substantial change of treatment strategy, and the outcome is not adversely affected because most incidental PVTs are of a lower Yerdel grade. Preoperative imaging is useful to identify those with a higher Yerdel grade to allow planning of surgical strategy during transplantation. PMID

  5. Phenomenological Relativistic Energy Density Functionals

    SciTech Connect

    Lalazissis, G. A.; Kartzikos, S.; Niksic, T.; Paar, N.; Vretenar, D.; Ring, P.

    2009-08-26

    The framework of relativistic nuclear energy density functionals is applied to the description of a variety of nuclear structure phenomena, not only in spherical and deformed nuclei along the valley of beta-stability, but also in exotic systems with extreme isospin values and close to the particle drip-lines. Dynamical aspects of exotic nuclear structure is explored using the fully consistent quasiparticle random-phase approximation based on the relativistic Hartree-Bogoliubov model. Recent applications of energy density functionals with explicit density dependence of the meson-nucleon couplings are presented.

  6. The Probable Connection Between Relativistic Shock Acceleration and Gamma Ray Bursts

    NASA Astrophysics Data System (ADS)

    Lieu, R.

    1998-01-01

    The recent detection of delayed Gamma ray burst (GRB) afterglows at longer wavelengths (van Paradijs et al 1997, Piro et al 1997, Bond 1997, Frail and Kulkarni 1997, Halpern et al 1997) supports strongly the notion that GRBs are produced at relativistic cosmological shocks (Pacynski 1986, Goodman 1986, Rees and Meszaros 1992). The current understanding is that these shocks are ultra-relativistic, with an upstream Lorentz factor Gamma ~300, and radiate the gamma rays as the shock accelerated electrons emit by the synchrotron or inverse-Compton process (Waxman 1997).

  7. Relativistic Hydrodynamics for Heavy-Ion Collisions

    ERIC Educational Resources Information Center

    Ollitrault, Jean-Yves

    2008-01-01

    Relativistic hydrodynamics is essential to our current understanding of nucleus-nucleus collisions at ultrarelativistic energies (current experiments at the Relativistic Heavy Ion Collider, forthcoming experiments at the CERN Large Hadron Collider). This is an introduction to relativistic hydrodynamics for graduate students. It includes a detailed…

  8. Relativistic treatment of inertial spin effects

    NASA Astrophysics Data System (ADS)

    Ryder, Lewis

    1998-03-01

    A relativistic spin operator for Dirac particles is identified and it is shown that a coupling of spin to angular velocity arises in the relativistic case, just as Mashhoon had speculated, and Hehl and Ni had demonstrated, in the non-relativistic case.

  9. Incidental and intentional encoding in young and elderly adults.

    PubMed

    Téllez-Alanís, Bernarda; Cansino, Selene

    2004-08-01

    Event-related potentials (ERPs) were recorded in young and elderly adults during the performance of an incidental encoding task (subjects were unexpectedly given a recognition test) followed by an intentional task (subjects expected the recognition test). Both tasks consisted of an encoding stage in which subjects classified words (natural/artificial) and a recognition stage in which they indicated whether the words were old (presented during the encoding stage) or new. In both groups and tasks, the ERPs, during encoding, differed as a function of subsequent recognition: the old words correctly recognized generated greater amplitude potentials than the incorrect ones. The memory processes expressed by these ERPs are preserved in elderly adults, independently of whether the information is incidentally or intentionally encoded. PMID:15257155

  10. Triggering memory recovery: effects of direct and incidental cuing.

    PubMed

    Handy, Justin D; Smith, Steven M

    2012-12-01

    The present study examined forgetting and recovery of narrative passages varying in emotional intensity, using what we refer to as the "dropout" method. Previous studies of this dropout procedure have used word lists as to-be-remembered material, but the present experiments used brief story vignettes with one-word titles (e.g., "Torture", "Insects"). These vignettes showed a strong dropout forgetting effect in free recall. Both text and picture cues from the vignettes eliminated the forgetting effect on a subsequent cued recall test. Vignette-related pictures in an incidental picture naming task, however, triggered little recovery of initially forgotten vignettes, as shown on a post-test. The results extend findings of large forgetting and memory recovery effects to materials that are more naturalistic than word lists. The findings also show that picture cues, which trigger strong memory recovery effects on a direct test of memory, had little effect on recovery when cues were encountered incidentally. PMID:23123684

  11. Concurrent movement impairs incidental but not intentional statistical learning.

    PubMed

    Stevens, David J; Arciuli, Joanne; Anderson, David I

    2015-07-01

    The effect of concurrent movement on incidental versus intentional statistical learning was examined in two experiments. In Experiment 1, participants learned the statistical regularities embedded within familiarization stimuli implicitly, whereas in Experiment 2 they were made aware of the embedded regularities and were instructed explicitly to learn these regularities. Experiment 1 demonstrated that while the control group were able to learn the statistical regularities, the resistance-free cycling group and the exercise group did not demonstrate learning. This is in contrast with the findings of Experiment 2, where all three groups demonstrated significant levels of learning. The results suggest that the movement demands, rather than the physiological stress, interfered with statistical learning. We suggest movement activates the striatum, which is not only responsible for motor control but also plays a role in incidental learning.

  12. Vividness of Visual Imagery and Incidental Recall of Verbal Cues, When Phenomenological Availability Reflects Long-Term Memory Accessibility

    PubMed Central

    D’Angiulli, Amedeo; Runge, Matthew; Faulkner, Andrew; Zakizadeh, Jila; Chan, Aldrich; Morcos, Selvana

    2013-01-01

    The relationship between vivid visual mental images and unexpected recall (incidental recall) was replicated, refined, and extended. In Experiment 1, participants were asked to generate mental images from imagery-evoking verbal cues (controlled on several verbal properties) and then, on a trial-by-trial basis, rate the vividness of their images; 30 min later, participants were surprised with a task requiring free recall of the cues. Higher vividness ratings predicted better incidental recall of the cues than individual differences (whose effect was modest). Distributional analysis of image latencies through ex-Gaussian modeling showed an inverse relation between vividness and latency. However, recall was unrelated to image latency. The follow-up Experiment 2 showed that the processes underlying trial-by-trial vividness ratings are unrelated to the Vividness of Visual Imagery Questionnaire (VVIQ), as further supported by a meta-analysis of a randomly selected sample of relevant literature. The present findings suggest that vividness may act as an index of availability of long-term sensory traces, playing a non-epiphenomenal role in facilitating the access of those memories. PMID:23382719

  13. Incidental finding of a microsporidian parasite from an AIDS patient.

    PubMed Central

    McDougall, R J; Tandy, M W; Boreham, R E; Stenzel, D J; O'Donoghue, P J

    1993-01-01

    Light microscopic examination of feces from a human immunodeficiency virus-positive patient with chronic diarrhea, anorexia, and lethargy revealed the presence of numerous refractile bodies resembling microsporidian spores. They were subsequently identified as belonging to the genus Nosema on the basis of their ultrastructural characteristics. However, the microsporidia were enclosed within striated muscle cells, suggesting that they were probably ingested in food; thus, this represented an incidental finding rather than a true infection. Images PMID:8432833

  14. Incidental Parathyroidectomy during Total Thyroidectomy: Risk Factors and Consequences

    PubMed Central

    Balalis, Dimitrios; Soulou, Vasiliki N.; Korkolis, Dimitrios P.; Plataniotis, Georgios; Gontikakis, Emmanouil

    2016-01-01

    Objective. To evaluate the incidence of accidental parathyroidectomy in our series of total thyroidectomies, to investigate its clinical and biochemical consequences, and to identify potential risk factors. Methods. Patients who underwent total thyroidectomy between January 2006 and December 2015 were retrospectively analyzed. Pathology reports were reviewed to identify those cases who had an incidental parathyroidectomy and these were compared to patients with no parathyroidectomy, in terms of clinical (age, sex, and symptoms of hypocalcemia), pathological (thyroid specimen weight, Hashimoto thyroiditis, and malignancy), and biochemical (serum calcium and phosphate levels) factors. Results. 281 patients underwent total thyroidectomy during the study period. Incidental parathyroidectomy was noticed in 24.9% of cases, with 44.3% of parathyroid glands found in an intrathyroidal location. Evidence of postoperative biochemical hypocalcemia was noticed in 28.6% of patients with parathyroidectomy, compared with 13.3% in the no-parathyroidectomy group (p = 0.003). Symptomatic hypocalcemia was observed in 5.7% and 3.8%, respectively (p = 0.49). Age, sex, thyroid specimen weight, Hashimoto thyroiditis, and malignancy did not differ significantly between the two groups. Conclusions. Our study found an association of incidental parathyroidectomy with transient postoperative biochemical hypocalcemia, but not with clinically symptomatic disease. Age, sex, thyroid gland weight, Hashimoto thyroiditis, and malignancy were not identified as risk factors.

  15. Incidental Parathyroidectomy during Total Thyroidectomy: Risk Factors and Consequences.

    PubMed

    Manatakis, Dimitrios K; Balalis, Dimitrios; Soulou, Vasiliki N; Korkolis, Dimitrios P; Plataniotis, Georgios; Gontikakis, Emmanouil

    2016-01-01

    Objective. To evaluate the incidence of accidental parathyroidectomy in our series of total thyroidectomies, to investigate its clinical and biochemical consequences, and to identify potential risk factors. Methods. Patients who underwent total thyroidectomy between January 2006 and December 2015 were retrospectively analyzed. Pathology reports were reviewed to identify those cases who had an incidental parathyroidectomy and these were compared to patients with no parathyroidectomy, in terms of clinical (age, sex, and symptoms of hypocalcemia), pathological (thyroid specimen weight, Hashimoto thyroiditis, and malignancy), and biochemical (serum calcium and phosphate levels) factors. Results. 281 patients underwent total thyroidectomy during the study period. Incidental parathyroidectomy was noticed in 24.9% of cases, with 44.3% of parathyroid glands found in an intrathyroidal location. Evidence of postoperative biochemical hypocalcemia was noticed in 28.6% of patients with parathyroidectomy, compared with 13.3% in the no-parathyroidectomy group (p = 0.003). Symptomatic hypocalcemia was observed in 5.7% and 3.8%, respectively (p = 0.49). Age, sex, thyroid specimen weight, Hashimoto thyroiditis, and malignancy did not differ significantly between the two groups. Conclusions. Our study found an association of incidental parathyroidectomy with transient postoperative biochemical hypocalcemia, but not with clinically symptomatic disease. Age, sex, thyroid gland weight, Hashimoto thyroiditis, and malignancy were not identified as risk factors. PMID:27635137

  16. Incidental Parathyroidectomy during Total Thyroidectomy: Risk Factors and Consequences

    PubMed Central

    Balalis, Dimitrios; Soulou, Vasiliki N.; Korkolis, Dimitrios P.; Plataniotis, Georgios; Gontikakis, Emmanouil

    2016-01-01

    Objective. To evaluate the incidence of accidental parathyroidectomy in our series of total thyroidectomies, to investigate its clinical and biochemical consequences, and to identify potential risk factors. Methods. Patients who underwent total thyroidectomy between January 2006 and December 2015 were retrospectively analyzed. Pathology reports were reviewed to identify those cases who had an incidental parathyroidectomy and these were compared to patients with no parathyroidectomy, in terms of clinical (age, sex, and symptoms of hypocalcemia), pathological (thyroid specimen weight, Hashimoto thyroiditis, and malignancy), and biochemical (serum calcium and phosphate levels) factors. Results. 281 patients underwent total thyroidectomy during the study period. Incidental parathyroidectomy was noticed in 24.9% of cases, with 44.3% of parathyroid glands found in an intrathyroidal location. Evidence of postoperative biochemical hypocalcemia was noticed in 28.6% of patients with parathyroidectomy, compared with 13.3% in the no-parathyroidectomy group (p = 0.003). Symptomatic hypocalcemia was observed in 5.7% and 3.8%, respectively (p = 0.49). Age, sex, thyroid specimen weight, Hashimoto thyroiditis, and malignancy did not differ significantly between the two groups. Conclusions. Our study found an association of incidental parathyroidectomy with transient postoperative biochemical hypocalcemia, but not with clinically symptomatic disease. Age, sex, thyroid gland weight, Hashimoto thyroiditis, and malignancy were not identified as risk factors. PMID:27635137

  17. Seismic Inversion Methods

    NASA Astrophysics Data System (ADS)

    Jackiewicz, Jason

    2009-09-01

    With the rapid advances in sophisticated solar modeling and the abundance of high-quality solar pulsation data, efficient and robust inversion techniques are crucial for seismic studies. We present some aspects of an efficient Fourier Optimally Localized Averaging (OLA) inversion method with an example applied to time-distance helioseismology.

  18. Seismic Inversion Methods

    SciTech Connect

    Jackiewicz, Jason

    2009-09-16

    With the rapid advances in sophisticated solar modeling and the abundance of high-quality solar pulsation data, efficient and robust inversion techniques are crucial for seismic studies. We present some aspects of an efficient Fourier Optimally Localized Averaging (OLA) inversion method with an example applied to time-distance helioseismology.

  19. A ''Voice Inversion Effect?''

    ERIC Educational Resources Information Center

    Bedard, Catherine; Belin, Pascal

    2004-01-01

    Voice is the carrier of speech but is also an ''auditory face'' rich in information on the speaker's identity and affective state. Three experiments explored the possibility of a ''voice inversion effect,'' by analogy to the classical ''face inversion effect,'' which could support the hypothesis of a voice-specific module. Experiment 1 consisted…

  20. Particle Acceleration in Relativistic Outflows

    NASA Technical Reports Server (NTRS)

    Bykov, Andrei; Gehrels, Neil; Krawczynski, Henric; Lemoine, Martin; Pelletier, Guy; Pohl, Martin

    2012-01-01

    In this review we confront the current theoretical understanding of particle acceleration at relativistic outflows with recent observational results on various source classes thought to involve such outflows, e.g. gamma-ray bursts, active galactic nuclei, and pulsar wind nebulae. We highlight the possible contributions of these sources to ultra-high-energy cosmic rays.

  1. Simplified Relativistic Force Transformation Equation.

    ERIC Educational Resources Information Center

    Stewart, Benjamin U.

    1979-01-01

    A simplified relativistic force transformation equation is derived and then used to obtain the equation for the electromagnetic forces on a charged particle, calculate the electromagnetic fields due to a point charge with constant velocity, transform electromagnetic fields in general, derive the Biot-Savart law, and relate it to Coulomb's law.…

  2. Paracentric inversions in humans: A review of 446 paracentric inversions with presentation of 120 new cases

    SciTech Connect

    Pettenati, M.J.; Rao, P.N.; Grss, F.

    1995-01-16

    We present a large review of 446 cases of paracentric inversions (PAI), including 120 new cases, to assess their incidence, distribution, inheritance, modes of ascertainment, interchromosomal effects, viable recombinant offspring, and clinical relevance. All 23 autosomes and sex chromosomes had inversions. However, none were identified in chromosome arms 18p, 19q, 20q, and Yp. PAI were most commonly reported in chromosomes 4, 16, 17, 18, 19, 20, 21, 22, and Y. Inversions were most common in chromosome arms 6p, 7q, 11q, and 14q and observed least in chromosome arms 2p, 2q, 3q, 4q, and 6q. Frequently encountered breakpoints included 3(p13p25), 6(p12p23), 6(p12p25), 7(q11q22), and 11(q21q23). Ascertainment was primarily incidental (54.5%), mental retardation and/or congenital anomalies (22.2%), spontaneous abortions (11.4%), associations with syndromes (3.0%), and infertility (2.0%) accounted for the remainder. Ascertainment was neither related to the length of the inverted segment nor to specific inversions except for PAI of Xq which often presented with manifestations of Ullrich-Turner syndrome. Sixty-six percent of PAI were inherited while 8.5% were de novo. Recombination was observed in 17 cases, 15 of which resulted in a monocentric chromosomal deletion or duplication. No common factors were identified that suggested a tendency toward recombination. The incidence of viable recombinants was estimated to be 3.8%. This review documents that PAI are perhaps more commonly identified than suggested in previous reviews. Despite the possible bias of ascertainment in some cases, there may be associated risks with PAI that require further examination. Our data suggest that PAI carriers do not appear to be free of risks of abnormalities or abnormal progeny and caution is recommended when counseling. 162 refs., 4 figs., 7 tabs.

  3. Fast lattice Boltzmann solver for relativistic hydrodynamics.

    PubMed

    Mendoza, M; Boghosian, B M; Herrmann, H J; Succi, S

    2010-07-01

    A lattice Boltzmann formulation for relativistic fluids is presented and numerically validated through quantitative comparison with recent hydrodynamic simulations of relativistic fluids. In order to illustrate its capability to handle complex geometries, the scheme is also applied to the case of a three-dimensional relativistic shock wave, generated by a supernova explosion, impacting on a massive interstellar cloud. This formulation opens up the possibility of exporting the proven advantages of lattice Boltzmann methods, namely, computational efficiency and easy handling of complex geometries, to the context of (mildly) relativistic fluid dynamics at large, from quark-gluon plasmas up to supernovae with relativistic outflows.

  4. Fast lattice Boltzmann solver for relativistic hydrodynamics.

    PubMed

    Mendoza, M; Boghosian, B M; Herrmann, H J; Succi, S

    2010-07-01

    A lattice Boltzmann formulation for relativistic fluids is presented and numerically validated through quantitative comparison with recent hydrodynamic simulations of relativistic fluids. In order to illustrate its capability to handle complex geometries, the scheme is also applied to the case of a three-dimensional relativistic shock wave, generated by a supernova explosion, impacting on a massive interstellar cloud. This formulation opens up the possibility of exporting the proven advantages of lattice Boltzmann methods, namely, computational efficiency and easy handling of complex geometries, to the context of (mildly) relativistic fluid dynamics at large, from quark-gluon plasmas up to supernovae with relativistic outflows. PMID:20867451

  5. Relativistic formulation of the Voigt profile

    NASA Astrophysics Data System (ADS)

    Wcisło, P.; Amodio, P.; Ciuryło, R.; Gianfrani, L.

    2015-02-01

    The relativistic formulation of the Voigt profile is reported for the spontaneous emission from an atomic or molecular cloud, in coincidence with a given spectral line. We considered the simultaneous occurrence of homogeneous broadening and thermal broadening, this latter being determined by the relativistic Doppler effect. Our formula for the relativistic Voigt profile reproduces those characterizing the two available limit cases, namely, the relativistic Gaussian profile and the classical Voigt convolution. The relativistic deformation of the Voigt profile was carefully quantified at different temperatures, in the case of the molecular hydrogen spectrum.

  6. Simulations of Relativistic Extragalactic Jets

    NASA Astrophysics Data System (ADS)

    Hughes, P. A.; Duncan, G. C.

    1994-05-01

    We present results for 2-D, axisymmetric simulations of flows with Lorentz factors ~ 5 -- 10, typical of values inferred for superluminal BL Lacs and QSOs. The simulations were performed with a numerical hydrodynamic code that admits relativistic flow speed. We exploit the property that the relativistic Euler equations for mass, momentum and total energy densities in the laboratory frame have the same form as the nonrelativistic equations, to solve for laboratory frame variables using a conventional Godunov-type scheme with approximate Riemann solver: the HLLE method. The relativistic nature of the flow is incorporated by performing a Lorentz transformation at every step, at each cell center or cell boundary where pressure, sound speed or velocity are required. Determination of the velocity in this manner is a robust algebraic procedure within which we can ensure that vrelativistic flows exhibit a less pronounced pattern of incident and reflection shocks on axis. For flows which have propagated to a fixed number of jet radii, the Kelvin-Helmholtz instability at the contact surface is much less evident in the high Lorentz factor cases, supporting the contention that relativistic flows are less prone to such instability. We describe how the morphology of the cocoon and shocked ambient gas change with increasing Lorentz factor. This work was supported by NSF grant AST 9120224 and by the Ohio Supercomputer Center from a Cray Research Software Development Grant.

  7. Central/incidental recall and selective attention in young and elderly adults.

    PubMed

    Mergler, N L; Dusek, J B; Hoyer, W J

    1977-01-01

    Central and incidental recall of young (Mean age=28.4) and elderly (Mean age=70.9) men and women was examined. As expected, statistically significant age differences were found for both central and incidental recall. For the eight items mean central recall (5.72) was significantly higher than mean incidental recall (2.56) at both age levels; mean incidental recall was significantly greater than chance for both age groups. Lack of an age X central/incidental interaction was interpreted as supporting a general recall deficit. No evidence was found to suggest an attentional focusing difference between young and elderly adults. Verbal labeling of the central stimuli had no effect on recall scores. Differential recall for each of eight positions of stimuli was also examined. Both age groups exhibited a spatial primacy-recency effect for central but not incidental recall. No support was obtained for an attentional interpretation of age-associated differences in learning.

  8. Relativistic ionization fronts in gas jets

    NASA Astrophysics Data System (ADS)

    Lemos, Nuno; Dias, J. M.; Gallacher, J. G.; Issac, R. C.; Fonseca, R. A.; Lopes, N. C.; Silva, L. O.; Mendonça, J. T.; Jaroszynski, D. A.

    2006-10-01

    A high-power ultra-short laser pulse propagating through a gas jet, ionizes the gas by tunnelling ionization, creating a relativistic plasma-gas interface. The relativistic ionization front that is created can be used to frequency up-shift electromagnetic radiation either in co-propagation or in counter-propagation configurations. In the counter-propagation configuration, ionization fronts can act as relativistic mirrors for terahertz radiation, leading to relativistic double Doppler frequency up-shift to the visible range. In this work, we identified and explored, the parameters that optimize the key features of relativistic ionization fronts for terahertz radiation reflection. The relativistic ionization front generated by a high power laser (TOPS) propagating in a supersonic gas jet generated by a Laval nozzle has been fully characterized. We have also performed detailed two-dimensional relativistic particle-in-cell simulations with Osiris 2.0 to analyze the generation and propagation of the ionization fronts.

  9. Incidental Bladder Cancer Detected on Multiparametric Magnetic Resonance Imaging of the Prostate Gland

    PubMed Central

    Sardari, Al; Thomas, John V.; Nix, Jeffrey W.; Pietryga, Jason A.; Sanyal, Rupan; Gordetsky, Jennifer B.; Rais-Bahrami, Soroush

    2015-01-01

    The increased use of axial imaging in various fields of medicine has led to an increased frequency of incidental findings, specifically incidental cancer lesions. Hence, as the use of multiparametric magnetic resonance imaging (MP-MRI) for prostate cancer detection, staging, and management becomes more widespread, the potential for additional incidental findings in the pelvis increases. Herein, we report the case of a man on active surveillance for low-grade, early-staged prostate cancer who underwent MP-MRI and was incidentally found to have a high-grade bladder cancer lesion. PMID:26783492

  10. 31 CFR 539.403 - Transactions incidental to a licensed transaction.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY WEAPONS OF MASS DESTRUCTION TRADE CONTROL REGULATIONS Interpretations § 539.403 Transactions incidental to a licensed transaction....

  11. Local thermodynamical equilibrium and the frame for a quantum relativistic fluid

    NASA Astrophysics Data System (ADS)

    Becattini, Francesco; Bucciantini, Leda; Grossi, Eduardo; Tinti, Leonardo

    2015-05-01

    We discuss the concept of local thermodynamical equilibrium in relativistic hydrodynamics in flat spacetime in a quantum statistical framework without an underlying kinetic description, suitable for strongly interacting fluids. We show that the appropriate definition of local equilibrium naturally leads to the introduction of a relativistic hydrodynamical frame in which the four-velocity vector is the one of a relativistic thermometer at equilibrium with the fluid, parallel to the inverse temperature four-vector , which then becomes a primary quantity. We show that this frame is the most appropriate for the expansion of the stress-energy tensor from local thermodynamical equilibrium and that therein the local laws of thermodynamics take on their simplest form. We discuss the difference between the frame and Landau frame and present an instance where they differ.

  12. Orphan γ-ray flares from relativistic blobs encountering luminous stars

    NASA Astrophysics Data System (ADS)

    Banasiński, P.; Bednarek, W.; Sitarek, J.

    2016-11-01

    We propose that {\\gamma} -rays in blazars can be produced during encounters of relativistic blobs of plasma with radiation field produced by luminous stars within (or close to) the jet. The blob is expected to contain relativistic electrons which comptonize stellar radiation to the GeV-TeV energies. Produced {\\gamma} -rays can initiate the Inverse Compton e+/- pair cascade in the stellar radiation. We propose that such a scenario can be responsible for the appearance of the so-called orphan {\\gamma} -ray flares. We show that the relativistic blob/luminous star collision model can explain the appearance of the extreme orphan {\\gamma} -ray flare observed in the GeV and sub-TeV energy range from the flat spectrum radio quasar PKS 1222+21.

  13. Solar inverse theory

    NASA Astrophysics Data System (ADS)

    Gough, D.

    1984-12-01

    Helioseismological inversion, as with the inversion of any other data, is divided into three phases. The first is the solution of the so-called forward problem: namely, the calculation of the eigenfrequencies of a theoretical equilibrium state. The second is an attempt to understand the results, either empirically by determining how those frequencies vary as chosen parameters defining the equilibrium model are varied, or analytically from asymptotic expansions in limiting cases of high order or degree. The third phase is to pose and solve an inverse problem, which seeks to find a plausible equilibrium model of the Sun whose eigenfrequencies are consistent with observation. The three phases are briefly discussed in this review, and the third, which is not yet widely used in helioseismology, is illustrated with some selected inversions of artificial solar data.

  14. Relativistic rocket: Dream and reality

    NASA Astrophysics Data System (ADS)

    Semyonov, Oleg G.

    2014-06-01

    The dream of interstellar flights persists since the first pioneers in astronautics and has never died. Many concepts of thruster capable to propel a rocket to the stars have been proposed and the most suitable among them are thought to be photon propulsion and propulsion by the products of proton-antiproton annihilation in magnetic nozzle. This article addresses both concepts allowing for cross-section of annihilation among other issues in order to show their vulnerability and to indicate the problems. The concept of relativistic matter propulsion is substantiated and discussed. The latter is argued to be the most straightforward way to build-up a relativistic rocket firstly because it is based on the existing technology of ion generators and accelerators and secondly because it can be stepped up in efflux power starting from interplanetary spacecrafts powered by nuclear reactors to interstellar starships powered by annihilation reactors. The problems imposed by thermodynamics and heat disposal are accentuated.

  15. Relativistic hydrodynamics on graphic cards

    NASA Astrophysics Data System (ADS)

    Gerhard, Jochen; Lindenstruth, Volker; Bleicher, Marcus

    2013-02-01

    We show how to accelerate relativistic hydrodynamics simulations using graphic cards (graphic processing units, GPUs). These improvements are of highest relevance e.g. to the field of high-energetic nucleus-nucleus collisions at RHIC and LHC where (ideal and dissipative) relativistic hydrodynamics is used to calculate the evolution of hot and dense QCD matter. The results reported here are based on the Sharp And Smooth Transport Algorithm (SHASTA), which is employed in many hydrodynamical models and hybrid simulation packages, e.g. the Ultrarelativistic Quantum Molecular Dynamics model (UrQMD). We have redesigned the SHASTA using the OpenCL computing framework to work on accelerators like graphic processing units (GPUs) as well as on multi-core processors. With the redesign of the algorithm the hydrodynamic calculations have been accelerated by a factor 160 allowing for event-by-event calculations and better statistics in hybrid calculations.

  16. Pythagoras Theorem and Relativistic Kinematics

    NASA Astrophysics Data System (ADS)

    Mulaj, Zenun; Dhoqina, Polikron

    2010-01-01

    In two inertial frames that move in a particular direction, may be registered a light signal that propagates in an angle with this direction. Applying Pythagoras theorem and principles of STR in both systems, we can derive all relativistic kinematics relations like the relativity of simultaneity of events, of the time interval, of the length of objects, of the velocity of the material point, Lorentz transformations, Doppler effect and stellar aberration.

  17. Generalized emissivity inverse problem.

    PubMed

    Ming, DengMing; Wen, Tao; Dai, XianXi; Dai, JiXin; Evenson, William E

    2002-04-01

    Inverse problems have recently drawn considerable attention from the physics community due to of potential widespread applications [K. Chadan and P. C. Sabatier, Inverse Problems in Quantum Scattering Theory, 2nd ed. (Springer Verlag, Berlin, 1989)]. An inverse emissivity problem that determines the emissivity g(nu) from measurements of only the total radiated power J(T) has recently been studied [Tao Wen, DengMing Ming, Xianxi Dai, Jixin Dai, and William E. Evenson, Phys. Rev. E 63, 045601(R) (2001)]. In this paper, a new type of generalized emissivity and transmissivity inverse (GETI) problem is proposed. The present problem differs from our previous work on inverse problems by allowing the unknown (emissivity) function g(nu) to be temperature dependent as well as frequency dependent. Based on published experimental information, we have developed an exact solution formula for this GETI problem. A universal function set suggested for numerical calculation is shown to be robust, making this inversion method practical and convenient for realistic calculations.

  18. The inverse electroencephalography pipeline

    NASA Astrophysics Data System (ADS)

    Weinstein, David Michael

    The inverse electroencephalography (EEG) problem is defined as determining which regions of the brain are active based on remote measurements recorded with scalp EEG electrodes. An accurate solution to this problem would benefit both fundamental neuroscience research and clinical neuroscience applications. However, constructing accurate patient-specific inverse EEG solutions requires complex modeling, simulation, and visualization algorithms, and to date only a few systems have been developed that provide such capabilities. In this dissertation, a computational system for generating and investigating patient-specific inverse EEG solutions is introduced, and the requirements for each stage of this Inverse EEG Pipeline are defined and discussed. While the requirements of many of the stages are satisfied with existing algorithms, others have motivated research into novel modeling and simulation methods. The principal technical results of this work include novel surface-based volume modeling techniques, an efficient construction for the EEG lead field, and the Open Source release of the Inverse EEG Pipeline software for use by the bioelectric field research community. In this work, the Inverse EEG Pipeline is applied to three research problems in neurology: comparing focal and distributed source imaging algorithms; separating measurements into independent activation components for multifocal epilepsy; and localizing the cortical activity that produces the P300 effect in schizophrenia.

  19. Direct and indirect inversions

    NASA Astrophysics Data System (ADS)

    Virieux, Jean; Brossier, Romain; Métivier, Ludovic; Operto, Stéphane; Ribodetti, Alessandra

    2016-06-01

    A bridge is highlighted between the direct inversion and the indirect inversion. They are based on fundamental different approaches: one is looking after a projection from the data space to the model space while the other one is reducing a misfit between observed data and synthetic data obtained from a given model. However, it is possible to obtain similar structures for model perturbation, and we shall focus on P-wave velocity reconstruction. This bridge is built up through the Born approximation linearizing the forward problem with respect to model perturbation and through asymptotic approximations of the Green functions of the wave propagation equation. We first describe the direct inversion and its ingredients and then we focus on a specific misfit function design leading to a indirect inversion. Finally, we shall compare this indirect inversion with more standard least-squares inversion as the FWI, enabling the focus on small weak velocity perturbations on one side and the speed-up of the velocity perturbation reconstruction on the other side. This bridge has been proposed by the group led by Raul Madariaga in the early nineties, emphasizing his leading role in efficient imaging workflows for seismic velocity reconstruction, a drastic requirement at that time.

  20. Relativistic opacities for astrophysical applications

    DOE PAGES

    Fontes, Christopher John; Fryer, Christopher Lee; Hungerford, Aimee L.; Hakel, Peter; Colgan, James Patrick; Kilcrease, David Parker; Sherrill, Manalo Edgar

    2015-06-29

    Here, we report on the use of the Los Alamos suite of relativistic atomic physics codes to generate radiative opacities for the modeling of astrophysically relevant plasmas under local thermodynamic equilibrium (LTE) conditions. The atomic structure calculations are carried out in fine-structure detail, including full configuration interaction. Three example applications are considered: iron opacities at conditions relevant to the base of the solar convection zone, nickel opacities for the modeling of stellar envelopes, and samarium opacities for the modeling of light curves produced by neutron star mergers. In the first two examples, comparisons are made between opacities that are generatedmore » with the fully and semi-relativistic capabilities in the Los Alamos suite of codes. As expected for these highly charged, iron-peak ions, the two methods produce reasonably similar results, providing confidence that the numerical methods have been correctly implemented. However, discrepancies greater than 10% are observed for nickel and investigated in detail. In the final application, the relativistic capability is used in a preliminary investigation of the complicated absorption spectrum associated with cold lanthanide elements.« less

  1. Relativistic Tennis Using Flying Mirror

    SciTech Connect

    Pirozhkov, A. S.; Kando, M.; Ma, J.; Fukuda, Y.; Chen, L.-M.; Daito, I.; Ogura, K.; Homma, T.; Hayashi, Y.; Kotaki, H.; Sagisaka, A.; Mori, M.; Koga, J. K.; Kawachi, T.; Daido, H.; Kimura, T.; Kato, Y.; Tajima, T.; Esirkepov, T. Zh.; Bulanov, S. V.

    2008-06-24

    Upon reflection from a relativistic mirror, the electromagnetic pulse frequency is upshifted and the duration is shortened by the factor proportional to the relativistic gamma-factor squared due to the double Doppler effect. We present the results of the proof-of-principle experiment for frequency upshifting of the laser pulse reflected from the relativistic 'flying mirror', which is a wake wave near the breaking threshold created by a strong driver pulse propagating in underdense plasma. Experimentally, the wake wave is created by a 2 TW, 76 fs Ti:S laser pulse from the JLITE-X laser system in helium plasma with the electron density of {approx_equal}4-6x10{sup 19} cm{sup -3}. The reflected signal is observed with a grazing-incidence spectrograph in 24 shots. The wavelength of the reflected radiation ranges from 7 to 14 nm, the corresponding frequency upshifting factors are {approx}55-115, and the gamma-factors are y = 4-6. The reflected signal contains at least 3x10{sup 7} photons/sr. This effect can be used to generate coherent high-frequency ultrashort pulses that inherit temporal shape and polarization from the original (low-frequency) ones. Apart from this, the reflected radiation contains important information about the wake wave itself, e.g. location, size, phase velocity, etc.

  2. Relativistic Tennis Using Flying Mirror

    NASA Astrophysics Data System (ADS)

    Pirozhkov, A. S.; Kando, M.; Esirkepov, T. Zh.; Ma, J.; Fukuda, Y.; Chen, L.-M.; Daito, I.; Ogura, K.; Homma, T.; Hayashi, Y.; Kotaki, H.; Sagisaka, A.; Mori, M.; Koga, J. K.; Kawachi, T.; Daido, H.; Bulanov, S. V.; Kimura, T.; Kato, Y.; Tajima, T.

    2008-06-01

    Upon reflection from a relativistic mirror, the electromagnetic pulse frequency is upshifted and the duration is shortened by the factor proportional to the relativistic gamma-factor squared due to the double Doppler effect. We present the results of the proof-of-principle experiment for frequency upshifting of the laser pulse reflected from the relativistic "flying mirror", which is a wake wave near the breaking threshold created by a strong driver pulse propagating in underdense plasma. Experimentally, the wake wave is created by a 2 TW, 76 fs Ti:S laser pulse from the JLITE-X laser system in helium plasma with the electron density of ≈4-6×1019 cm-3. The reflected signal is observed with a grazing-incidence spectrograph in 24 shots. The wavelength of the reflected radiation ranges from 7 to 14 nm, the corresponding frequency upshifting factors are ˜55-115, and the gamma-factors are y = 4-6. The reflected signal contains at least 3×107 photons/sr. This effect can be used to generate coherent high-frequency ultrashort pulses that inherit temporal shape and polarization from the original (low-frequency) ones. Apart from this, the reflected radiation contains important information about the wake wave itself, e.g. location, size, phase velocity, etc.

  3. Outcomes after incidental durotomy during first-time lumbar discectomy

    PubMed Central

    Desai, Atman; Ball, Perry A.; Bekelis, Kimon; Lurie, Jon; Mirza, Sohail K.; Tosteson, Tor D.; Weinstein, James N.

    2015-01-01

    Introduction Incidental durotomy is an infrequent but well-recognized complication during lumbar disc surgery. The effect of a durotomy on long-term outcomes is however, controversial. We sought to examine whether the occurrence of durotomy during surgery impacts long-term clinical outcome. Methods Spine Patient Outcomes Research Trial (SPORT) cohort participants with a confirmed diagnosis of intervertebral disc herniation (IDH) undergoing standard first-time open discectomy were followed from baseline at 6 weeks, 3, 6, and 12 months, and yearly thereafter, at 13 spine clinics in 11 US states. Patient data from this prospectively gathered database was reviewed. As of May 2009, the mean (SD) follow-up among all analyzed IDH patients was 41.5 (14.5) months (No durotomy: 41.4 vs. Had durotomy: 40.2, p-value<0.68). The median (range) follow-up time among all analyzed IDH patients was 47 (1 to 95) months. Results 799 patients underwent first-time lumbar discectomy. There was an incidental durotomy in 25 (3.1%) of these patients. There were no significant differences with or without durotomy in age, sex, race, body mass index, the prevalence of smoking, diabetes, hypertension, or herniation level or type. When outcome differences between the groups were analyzed, the durotomy group was found to have significantly increased operative duration, operative blood loss and inpatient stay. However, there were no differences in incidence of nerve root injury, post-op mortality, additional surgeries or SF-36 scores of bodily pain or physical function, or Oswestry Disability Index at 1, 2, 3 or 4 years. Conclusions Incidental durotomy during first time lumbar discectomy does not appear to impact long-term outcome in affected patients. PMID:21375385

  4. Paleoindian unifacial stone tool 'spurs': intended accessories or incidental accidents?

    PubMed

    Eren, Metin I; Jennings, Thomas A; Smallwood, Ashley M

    2013-01-01

    Paleoindian unifacial stone tools frequently exhibit distinct, sharp projections, known as "spurs". During the last two decades, a theoretically and empirically informed interpretation-based on individual artifact analysis, use-wear, tool-production techniques, and studies of resharpening-suggested that spurs were sometimes created intentionally via retouch, and other times created incidentally via resharpening or knapping accidents. However, more recently Weedman strongly criticized the inference that Paleoindian spurs were ever intentionally produced or served a functional purpose, and asserted that ethnographic research "demonstrates that the presence of so called 'graver' spurs does not have a functional significance." While ethnographic data cannot serve as a direct test of the archaeological record, we used Weedman's ethnographic observations to create two quantitative predictions of the Paleoindian archaeological record in order to directly examine the hypothesis that Paleoindian spurs were predominantly accidents occurring incidentally via resharpening and reshaping. The first prediction is that the frequency of spurs should increase as tool reduction proceeds. The second prediction is that the frequency of spurs should increase as tool breakage increases. An examination of 563 unbroken tools and 629 tool fragments from the Clovis archaeological record of the North American Lower Great Lakes region showed that neither prediction was consistent with the notion that spurs were predominately accidents. Instead, our results support the prevailing viewpoint that spurs were sometimes created intentionally via retouch, and other times, created incidentally via resharpening or knapping accidents. Behaviorally, this result is consistent with the notion that unifacial stone tools were multifunctional implements that enhanced the mobile lifestyle of Pleistocene hunter-gatherers.

  5. The role of biopsy in incidental renal tumours☆

    PubMed Central

    Al-Marhoon, Mohammed S.

    2011-01-01

    Purpose Historically, the biopsy of renal masses was not advocated, and to date there remains some controversy on the role of biopsy for renal masses in making treatment decisions. With the widespread use of imaging methods, the incidental diagnosis of renal masses has increased, necessitating renal biopsies to better plan the management of these tumours. Here I review previous reports to define the role of biopsy in incidental renal tumours. Methods Data were obtained from English-language studies listed in PubMed on the use of renal biopsy for evaluating incidental solid small renal tumours. Results The biopsy of small renal tumours is increasingly accepted due to: the increase in the incidence of small renal tumours; the finding that a significant number of these tumours are benign; the availability of new management options, such as ablative therapy and surveillance strategies; that imaging alone is unable to predict the biological behaviour of these tumours; and advances in the pathological evaluation of the biopsies. The biopsy procedure has an acceptable complication rate but is not free of limitations. The current recommendations for the use of renal biopsy in small renal tumours are: to help in differentiating benign from malignant renal tumours; before or during ablative therapies and during the follow-up after ablative therapies, for defining treatment success or failure; and to exclude nonrenal cell primary tumours (metastasis and lymphoma) or benign conditions (abscess), which may not require surgery. Conclusions The biopsy of small renal tumours is a safe and accurate procedure, and can help in the planning of definitive patient management. PMID:26579260

  6. Incidental Intravascular Lipoleiomyomatosis in A Hysterectomy Specimen: How To Manage?

    PubMed Central

    Aslanova, Rakhshanda; Can, Nuray; Okten, Sabri Berkem; Aslan, Mehmet Musa

    2015-01-01

    Leiomyomas are common benign tumors in female gynaecologic surgery. They are originated from smooth muscle cells of the uterus and/or sometimes of the uterine vessels. Intravascular lipoleiomyomatosis is a very rare form of leiomyomas which grow within veins and can extend up to vena cava inferior and right heart chamber with cardiac symptoms and is diagnosed by cardiovascular surgeons. We report a case of incidental intravascular lipoleiomyomatosis which was confined to the uterus being diagnosed after a total abdominal hysterectomy by pathology and its management strategy. PMID:25738043

  7. A Unique Incidental Finding in Two Young Dancers

    PubMed Central

    Miller, Marshal N.; Close, Jeremy D.

    2015-01-01

    Dancers frequently present to the sports medicine clinic with a variety of lower extremity complaints ranging from acute and traumatic injuries to more chronic, overuse injuries. This case series depicts a similar and unique incidental radiographic finding found in 2 young dancers seen at the same sports medicine clinic. While the findings are likely benign and unrelated to both patients’ initial presentation, the finding of acroosteolysis can be found in more serious systemic and genetic processes as well an early finding in repetitive trauma. PMID:26502417

  8. Multifocal peritoneal calcifying fibrous tumour: incidental finding at cholecystectomy

    PubMed Central

    Gatt, Noel; Falzon, Sharon; Ratynska, Marzena

    2011-01-01

    Calcifying fibrous tumour (CFT) is a benign tumour of elusive aetiology and a potential for local recurrence. Despite its peculiar histological characteristics it can still be confused with interrelated differential diagnosis like inflammatory myofibroblastic tumour (IMT) or solitary fibrous tumours. The clinical differential diagnosis is however much wider. To date seven cases of multiple peritoneal CFTs are on record. The authors present a case discovered incidentally during laparoscopic cholecystectomy, with no previous history and no radiological diagnosis achieved despite having undergone magnetic resonance cholangiopancreatography (MRCP) and normal routine perioperative investigation. The patient is disease-free 12 months after diagnosis. The case report is followed by a detailed literature review. PMID:22689663

  9. [Fundus albipunctatus incidentally discovered in a black African man].

    PubMed

    Kouassi, F X; Koffi, K V; Safede, K; Daccache, W; Cochener, B

    2006-05-01

    Fundus albipunctatus is a recessive autosomal disease classified as one of the causes of congenital stationary night blindness. It is characterized by early hemeralopia beginning in infancy. We report the incidental discovery of the disease in a 23-year-old black African man with late hemeralopia onset. During the 4 years of follow-up, visual acuity, ERG, and visual field remained normal. We underline the possibility of late hemeralopia onset and discuss the possible progressive features of this disease. Progression may be conditioned by the mutation of the RDH5 gene, which codes for retinol dehydrogenase-5.

  10. Relativistic high harmonics and (sub-)attosecond pulses: relativistic spikes and relativistic mirror

    NASA Astrophysics Data System (ADS)

    Pukhov, A.; Baeva, T.; An der Brügge, D.; Münster, S.

    2009-11-01

    Using particle-in-cell simulations, we study high harmonic generation from overdense plasmas in the relativistic regime. Different incidence angles as well as different laser polarizations are considered and scalings are recovered. It is shown that the theory of relativistic spikes and the BGP power-law spectra [Phys. Rev. E 74, 046404 (2006)] describes well the normal incidence and s-polarized obliquely incident laser pulses. In the case of p-polarized laser pulses, exceptions from the BGP theory can appear when the quasi-static vector potential build-up at the plasma boundary becomes equal to that of the laser. In this case, the spectrum flattens significantly and has a lower cutoff.

  11. 77 FR 61017 - Draft Habitat Conservation Plan and Application for an Incidental Take Permit, Yamhill County, OR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-05

    ...'' of the endangered Fender's blue butterfly incidental to otherwise lawful activities associated with... and mitigate the impacts of incidental take of the Fender's blue butterfly caused by covered... regulatory assurances for potential impacts on the Fender's blue butterfly (Icaricia icarioides...

  12. Relativistic Navigation: A Theoretical Foundation

    NASA Technical Reports Server (NTRS)

    Turyshev, Slava G.

    1996-01-01

    We present a theoretical foundation for relativistic astronomical measurements in curved space-time. In particular, we discuss a new iterative approach for describing the dynamics of an isolated astronomical N-body system in metric theories of gravity. To do this, we generalize the Fock-Chandrasekhar method of the weak-field and slow-motion approximation (WFSMA) and develop a theory of relativistic reference frames (RF's) for a gravitationally bounded many-extended-body problem. In any proper RF constructed in the immediate vicinity of an arbitrary body, the N-body solutions of the gravitational field equations are formally presented as a sum of the Riemann-flat inertial space-time, the gravitational field generated by the body itself, the unperturbed solutions for each body in the system transformed to the coordinates of this proper RF, and the gravitational interaction term. We develop the basic concept of a general WFSMA theory of the celestial RF's applicable to a wide class of metric theories of gravity and an arbitrary model of matter distribution. We apply the proposed method to general relativity. Celestial bodies are described using a perfect fluid model; as such, they possess any number of internal mass and current multipole moments that explicitly characterize their internal structures. The obtained relativistic corrections to the geodetic equations of motion arise because of a coupling of the bodies' multiple moments to the surrounding gravitational field. The resulting relativistic transformations between the different RF's extend the Poincare group to the motion of deformable self-gravitating bodies. Within the present accuracy of astronomical measurements we discuss the properties of the Fermi-normal-like proper RF that is defined in the immediate vicinity of the extended compact bodies. We further generalize the proposed approximation method and include two Eddington parameters (gamma, Beta). This generalized approach was used to derive the

  13. Relativistic radiation transport in dispersive media

    SciTech Connect

    Kichenassamy, S.; Krikorian, R.A.

    1985-10-15

    A general-relativistic radiative transfer equation in an isotropic, weakly absorbing, nonmagnetized dispersive medium is derived using the kinetic-theoretical approach and the relativistic Hamiltonian theory of geometrical optics in those media. It yields the generally accepted classical equation in the special-relativistic approximation and in stationary conditions. The influence of the gravitational field and of space-time variations of the refractive index n on the radiation distribution is made explicit in the case of spherical symmetry.

  14. Mesoscopic Superposition States in Relativistic Landau Levels

    SciTech Connect

    Bermudez, A.; Martin-Delgado, M. A.; Solano, E.

    2007-09-21

    We show that a linear superposition of mesoscopic states in relativistic Landau levels can be built when an external magnetic field couples to a relativistic spin 1/2 charged particle. Under suitable initial conditions, the associated Dirac equation produces unitarily superpositions of coherent states involving the particle orbital quanta in a well-defined mesoscopic regime. We demonstrate that these mesoscopic superpositions have a purely relativistic origin and disappear in the nonrelativistic limit.

  15. The Effects of Distance Education and Student Involvement on Incidental Learning

    ERIC Educational Resources Information Center

    Konetes, George D.

    2011-01-01

    Incidental learning is an occurrence that is not generally accounted for using the traditional methods of instructional objectives and outcomes assessment. This type of learning occurs in part as a product of social interaction and active involvement in both online and onsite courses. This study examines various incidental learning outcomes and…

  16. 46 CFR 276.1 - Partial repayment-incidental domestic trading.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Partial repayment-incidental domestic trading. 276.1 Section 276.1 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION REGULATIONS AFFECTING...—incidental domestic trading. In every instance where a vessel, with respect to which a...

  17. Incidentally detected ectopic right kidney following total abdominal hysterectomy and bilateral salpingoophorectomy.

    PubMed

    Aksoy, Nazlı; Güzel, Ali İrfan; Doğanay, Melike

    2014-01-01

    Congenital organ anomalies in surgical patients can be incidentally detected during operation. A pelvis located right kidney was found incidentally in 54 year-old women after total abdominal histerectomy and bilateral salpingoophorectomy. The clinical importance of pelvic kidney detected during the surgery was discussed in this case report.

  18. Spectrum of intracranial incidental findings on pediatric brain magnetic resonance imaging: What clinician should know?

    PubMed

    Gupta, Surya N; Gupta, Vikash S; White, Andrew C

    2016-08-01

    Intracranial incidental findings on magnetic resonance imaging (MRI) of the brain continue to generate interest in healthy control, research, and clinical subjects. However, in clinical practice, the discovery of incidental findings acts as a "distractor". This review is based on existing heterogeneous reports, their clinical implications, and how the results of incidental findings influence clinical management. This draws attention to the followings: (1) the prevalence of clinically significant incidental findings is low; (2) there is a lack of a systematic approach to classification; and discusses (3) how to deal with the detected incidental findings based a proposed common clinical profile. Individualized neurological care requires an active discussion regarding the need for neuroimaging. Clinical significance of incidental findings should be decided based on lesion's neuroradiologic characteristics in the given clinical context. Available evidence suggests that the outcome of an incidentally found "serious lesion in children" is excellent. Future studies of intracranial incidental findings on pediatric brain MRI should be focused on a homogeneous population. The study should address this clinical knowledge based review powered by the statistical analyses. PMID:27610341

  19. 19 CFR 148.17 - Declaration on arrival incidental to further foreign travel.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... foreign travel. 148.17 Section 148.17 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF... § 148.17 Declaration on arrival incidental to further foreign travel. (a) Declaration on incidental arrival. A resident who enters the United States merely as an incident of foreign travel and who...

  20. 29 CFR 793.13 - Limitation on related and incidental work.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Limitation on related and incidental work. 793.13 Section... AND TELEVISION STATION EMPLOYEES FROM OVERTIME PAY REQUIREMENTS UNDER SECTION 13(b)(9) OF THE FAIR LABOR STANDARDS ACT Requirements for Exemption § 793.13 Limitation on related and incidental work....

  1. 29 CFR 793.13 - Limitation on related and incidental work.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Limitation on related and incidental work. 793.13 Section... AND TELEVISION STATION EMPLOYEES FROM OVERTIME PAY REQUIREMENTS UNDER SECTION 13(b)(9) OF THE FAIR LABOR STANDARDS ACT Requirements for Exemption § 793.13 Limitation on related and incidental work....

  2. 29 CFR 793.13 - Limitation on related and incidental work.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Limitation on related and incidental work. 793.13 Section... AND TELEVISION STATION EMPLOYEES FROM OVERTIME PAY REQUIREMENTS UNDER SECTION 13(b)(9) OF THE FAIR LABOR STANDARDS ACT Requirements for Exemption § 793.13 Limitation on related and incidental work....

  3. 19 CFR 148.17 - Declaration on arrival incidental to further foreign travel.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... foreign travel. 148.17 Section 148.17 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF... § 148.17 Declaration on arrival incidental to further foreign travel. (a) Declaration on incidental arrival. A resident who enters the United States merely as an incident of foreign travel and who...

  4. 19 CFR 148.17 - Declaration on arrival incidental to further foreign travel.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... foreign travel. 148.17 Section 148.17 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF... § 148.17 Declaration on arrival incidental to further foreign travel. (a) Declaration on incidental arrival. A resident who enters the United States merely as an incident of foreign travel and who...

  5. 76 FR 71940 - Takes of Marine Mammals Incidental to Specified Activities; Physical Oceanographic Studies in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-21

    ...NMFS has received an application from the United States Navy (Navy) for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to conducting physical oceanographic studies in the southwest Indian Ocean, January through February, 2012. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue an IHA to the......

  6. Incidental Focus on Form in Teacher-Learner and Learner-Learner Interactions

    ERIC Educational Resources Information Center

    Zhao, Susan Yuqin; Bitchener, John

    2007-01-01

    Current attention in L2 acquisition research focuses on the integration of message-focused and form-focused instruction. One way to accomplish this is through the incidental focus on form during meaning-focused activities. Some studies have investigated incidental focus on form in different contexts and shown that it exists in L2 classes and…

  7. 50 CFR 18.24 - Taking incidental to commercial fishing operations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Taking incidental to commercial fishing... commercial fishing operations. Persons may take marine mammals incidental to commercial fishing operations... of marine mammals permitted in the course of commercial fishing operations be reduced...

  8. 50 CFR 18.24 - Taking incidental to commercial fishing operations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Taking incidental to commercial fishing... commercial fishing operations. Persons may take marine mammals incidental to commercial fishing operations... of marine mammals permitted in the course of commercial fishing operations be reduced...

  9. 50 CFR 18.24 - Taking incidental to commercial fishing operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Taking incidental to commercial fishing... commercial fishing operations. Persons may take marine mammals incidental to commercial fishing operations... of marine mammals permitted in the course of commercial fishing operations be reduced...

  10. 50 CFR 18.24 - Taking incidental to commercial fishing operations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Taking incidental to commercial fishing... commercial fishing operations. Persons may take marine mammals incidental to commercial fishing operations... of marine mammals permitted in the course of commercial fishing operations be reduced...

  11. 50 CFR 18.24 - Taking incidental to commercial fishing operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Taking incidental to commercial fishing... commercial fishing operations. Persons may take marine mammals incidental to commercial fishing operations... of marine mammals permitted in the course of commercial fishing operations be reduced...

  12. 29 CFR 793.13 - Limitation on related and incidental work.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... requirements. One limitation is that the work must be an incident to the employee's primary occupation. The... 29 Labor 3 2011-07-01 2011-07-01 false Limitation on related and incidental work. 793.13 Section... LABOR STANDARDS ACT Requirements for Exemption § 793.13 Limitation on related and incidental work....

  13. Involvement in Traditional Cultural Practices and American Indian Children's Incidental Recall of a Folktale

    ERIC Educational Resources Information Center

    Tsethlikai, Monica; Rogoff, Barbara

    2013-01-01

    This study examined incidental recall of a folktale told to 91 Tohono O'odham American Indian children (average age 9 years) who either were directly addressed or had the opportunity to overhear the telling of the folktale. Learning from surrounding incidental events contrasts with learning through direct instruction common in Western schooling,…

  14. 31 CFR 537.516 - Importation of Burmese-origin articles and incidental transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Importation of Burmese-origin articles and incidental transactions. 537.516 Section 537.516 Money and Finance: Treasury Regulations... Importation of Burmese-origin articles and incidental transactions. (a) The importation of an article that...

  15. 31 CFR 537.516 - Importation of Burmese-origin articles and incidental transactions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Importation of Burmese-origin articles and incidental transactions. 537.516 Section 537.516 Money and Finance: Treasury Regulations Relating... Burmese-origin articles and incidental transactions. (a) The importation of an article that is a...

  16. 31 CFR 537.516 - Importation of Burmese-origin articles and incidental transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Importation of Burmese-origin articles and incidental transactions. 537.516 Section 537.516 Money and Finance: Treasury Regulations Relating... Burmese-origin articles and incidental transactions. (a) The importation of an article that is a...

  17. 31 CFR 537.516 - Importation of Burmese-origin articles and incidental transactions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Importation of Burmese-origin articles and incidental transactions. 537.516 Section 537.516 Money and Finance: Treasury Regulations Relating... Burmese-origin articles and incidental transactions. (a) The importation of an article that is a...

  18. 77 FR 65864 - Receipt of an Application for Incidental Take Permit (16230)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-31

    ... monitor, minimize, and mitigate the incidental take of ESA-listed sea turtles. The conservation plan... permit application is for the incidental take of ESA-listed adult and juvenile sea turtles associated... (Dermochelys coriacea), hawksbill (Eretmochelys imbricata), and Kemp's ridley (Lepidochelys kempii) sea...

  19. 77 FR 23463 - Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Space Vehicle and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ... Marine Mammals Incidental to Space Vehicle and Missile Launch Operations at Kodiak Launch Complex, Alaska... two species of pinnipeds incidental to space vehicle and missile launch operations at the Kodiak... launch operations at the KLC, were issued on March 22, 2011 (76 FR 16311, March 23, 2011), and remain...

  20. 78 FR 78824 - Takes of Marine Mammals Incidental to Specified Activities; Rockaway Delivery Lateral Project off...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ... proposes to expand its pipeline system to meet immediate and future demand for natural gas in the New York... have received an application from Transcontinental Gas Pipe Line Company, LLC (Transco) for an Incidental Harassment Authorization to take marine mammals, by harassment, incidental to expanding a...

  1. 19 CFR 148.17 - Declaration on arrival incidental to further foreign travel.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... foreign travel. 148.17 Section 148.17 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF... § 148.17 Declaration on arrival incidental to further foreign travel. (a) Declaration on incidental arrival. A resident who enters the United States merely as an incident of foreign travel and who...

  2. 30 CFR 750.21 - Coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal extraction incidental to the extraction of... ENFORCEMENT, DEPARTMENT OF THE INTERIOR INDIAN LANDS PROGRAM REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS ON INDIAN LANDS § 750.21 Coal extraction incidental to the extraction of other...

  3. 30 CFR 750.21 - Coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Coal extraction incidental to the extraction of... ENFORCEMENT, DEPARTMENT OF THE INTERIOR INDIAN LANDS PROGRAM REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS ON INDIAN LANDS § 750.21 Coal extraction incidental to the extraction of other...

  4. 30 CFR 750.21 - Coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Coal extraction incidental to the extraction of... ENFORCEMENT, DEPARTMENT OF THE INTERIOR INDIAN LANDS PROGRAM REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS ON INDIAN LANDS § 750.21 Coal extraction incidental to the extraction of other...

  5. 30 CFR 750.21 - Coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Coal extraction incidental to the extraction of... ENFORCEMENT, DEPARTMENT OF THE INTERIOR INDIAN LANDS PROGRAM REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS ON INDIAN LANDS § 750.21 Coal extraction incidental to the extraction of other...

  6. 30 CFR 750.21 - Coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Coal extraction incidental to the extraction of... ENFORCEMENT, DEPARTMENT OF THE INTERIOR INDIAN LANDS PROGRAM REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS ON INDIAN LANDS § 750.21 Coal extraction incidental to the extraction of other...

  7. 78 FR 63489 - Endangered and Threatened Wildlife and Plants; Receipt of Application for Incidental Take Permit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-24

    ... Incidental Take Permit; Availability of Proposed Low- Effect Habitat Conservation Plan; Clermont Land... application for incidental take permit (ITP). Clermont Land Development, LLC requests a 10-year ITP under the Endangered Species Act of 1973, as amended (Act). We request public comment on the permit application...

  8. An "Adventure" of MBA Students in Europe: How Volcanic Ash Produced an Incidental Learning Experience

    ERIC Educational Resources Information Center

    Vazquez, Ana Claudia Souza; Ruas, Roberto Lima; Cervo, Clarissa S.; Hutz, Claudio Simon

    2013-01-01

    Because the volcanic ash that affected air travel in Western Europe in 2010 was considered as one of the most meaningful learning experiences by a group of MBA students, this article aims to outline the main aspects of an incidental learning situation, rarely described on management education literature. Incidental learning is an unsystematic…

  9. 76 FR 67419 - Takes of Marine Mammals Incidental to Specified Activities; Piling and Structure Removal in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-01

    ... affected species or stocks, NMFS considers a number of criteria regarding the impact of the proposed action... Natural Resources (DNR) to incidentally harass, by Level B harassment only, small numbers of harbor seals... Commerce to authorize, upon request, the incidental, but not intentional, taking of small numbers of...

  10. 30 CFR 921.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 921.702 Section 921.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of the chapter, Exemption for Coal Extraction Incidental to the Extraction...

  11. 30 CFR 905.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 905.702 Section 905.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction...

  12. 30 CFR 933.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 933.702 Section 933.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction...

  13. 30 CFR 947.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 947.702 Section 947.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction...

  14. 30 CFR 937.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 937.702 Section 937.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...

  15. 30 CFR 941.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 941.702 Section 941.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction...

  16. 30 CFR 912.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 912.702 Section 912.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...

  17. 30 CFR 910.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 910.702 Section 910.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...

  18. 30 CFR 942.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 942.702 Section 942.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...

  19. 30 CFR 939.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 939.702 Section 939.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction...

  20. 30 CFR 903.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 903.702 Section 903.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...

  1. 30 CFR 922.702 - Exemption for coal extraction incidental to the extraction of other minerals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 922.702 Section 922.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...

  2. Spectrum of intracranial incidental findings on pediatric brain magnetic resonance imaging: What clinician should know?

    PubMed Central

    Gupta, Surya N; Gupta, Vikash S; White, Andrew C

    2016-01-01

    Intracranial incidental findings on magnetic resonance imaging (MRI) of the brain continue to generate interest in healthy control, research, and clinical subjects. However, in clinical practice, the discovery of incidental findings acts as a “distractor”. This review is based on existing heterogeneous reports, their clinical implications, and how the results of incidental findings influence clinical management. This draws attention to the followings: (1) the prevalence of clinically significant incidental findings is low; (2) there is a lack of a systematic approach to classification; and discusses (3) how to deal with the detected incidental findings based a proposed common clinical profile. Individualized neurological care requires an active discussion regarding the need for neuroimaging. Clinical significance of incidental findings should be decided based on lesion’s neuroradiologic characteristics in the given clinical context. Available evidence suggests that the outcome of an incidentally found “serious lesion in children” is excellent. Future studies of intracranial incidental findings on pediatric brain MRI should be focused on a homogeneous population. The study should address this clinical knowledge based review powered by the statistical analyses. PMID:27610341

  3. Spectrum of intracranial incidental findings on pediatric brain magnetic resonance imaging: What clinician should know?

    PubMed Central

    Gupta, Surya N; Gupta, Vikash S; White, Andrew C

    2016-01-01

    Intracranial incidental findings on magnetic resonance imaging (MRI) of the brain continue to generate interest in healthy control, research, and clinical subjects. However, in clinical practice, the discovery of incidental findings acts as a “distractor”. This review is based on existing heterogeneous reports, their clinical implications, and how the results of incidental findings influence clinical management. This draws attention to the followings: (1) the prevalence of clinically significant incidental findings is low; (2) there is a lack of a systematic approach to classification; and discusses (3) how to deal with the detected incidental findings based a proposed common clinical profile. Individualized neurological care requires an active discussion regarding the need for neuroimaging. Clinical significance of incidental findings should be decided based on lesion’s neuroradiologic characteristics in the given clinical context. Available evidence suggests that the outcome of an incidentally found “serious lesion in children” is excellent. Future studies of intracranial incidental findings on pediatric brain MRI should be focused on a homogeneous population. The study should address this clinical knowledge based review powered by the statistical analyses.

  4. Incidental Vocabulary Learning in Second Language Acquisition: A Literature Review (Aprendizaje incidental de vocabulario en la adquisición de una segunda lengua: una revisión de literatura)

    ERIC Educational Resources Information Center

    Restrepo Ramos, Falcon Dario

    2015-01-01

    This literature review aims to analyze previous studies that address the incidental learning of vocabulary in second language acquisition. The articles included in this literature review look into the understanding of vocabulary learning through incidental means, the relationship of reading and incidental vocabulary learning, and the strategies…

  5. Dissipation in relativistic pair-plasma reconnection

    SciTech Connect

    Hesse, Michael; Zenitani, Seiji

    2007-11-15

    An investigation into the relativistic dissipation in magnetic reconnection is presented. The investigated system consists of an electron-positron plasma. A relativistic generalization of Ohm's law is derived. A set of numerical simulations is analyzed, composed of runs with and without guide magnetic field, and of runs with different species temperatures. The calculations indicate that the thermal inertia-based dissipation process survives in relativistic plasmas. For antiparallel reconnection, it is found that the pressure tensor divergence remains the sole contributor to the reconnection electric field, whereas relativistic guide field reconnection exhibits a similarly important role of the bulk inertia terms.

  6. Relativistic Bernstein waves in a degenerate plasma

    SciTech Connect

    Ali, Muddasir; Hussain, Azhar; Murtaza, G.

    2011-09-15

    Bernstein mode for a relativistic degenerate electron plasma is investigated. Using relativistic Vlasov-Maxwell equations, a general expression for the conductivity tensor is derived and then employing Fermi-Dirac distribution function a generalized dispersion relation for the Bernstein mode is obtained. Two limiting cases, i.e., non-relativistic and ultra-relativistic are discussed. The dispersion relations obtained are also graphically presented for some specific values of the parameters depicting how the propagation characteristics of Bernstein waves as well as the Upper Hybrid oscillations are modified with the increase in plasma number density.

  7. Dissipation in Relativistic Pair-Plasma Reconnection

    NASA Technical Reports Server (NTRS)

    Hesse, Michael; Zenitani, Seiji

    2007-01-01

    We present an investigation of the relativistic dissipation in magnetic reconnection. The investigated system consists of an electron-positron plasma. A relativistic generalization of Ohm's law is derived. We analyze a set of numerical simulations, composed of runs with and without guide magnetic field, and of runs with different species temperatures. The calculations indicate that the thermal inertia-based dissipation process survives in relativistic plasmas. For anti-parallel reconnection, it is found that the pressure tensor divergence remains the sole contributor to the reconnection electric field, whereas relativistic guide field reconnection exhibits a similarly important role of the bulk inertia terms.

  8. Particle Acceleration and Nonthermal Emission in Relativistic Astrophysical Shocks

    NASA Astrophysics Data System (ADS)

    Sironi, Lorenzo

    The common observational feature of Pulsar Wind Nebulae (PWNe), gamma-ray bursts (GRBs), and AGN jets is a broad nonthermal spectrum of synchrotron and inverse Compton radiation. It is usually assumed that the emitting electrons are accelerated to a power-law distribution at relativistic shocks, via the so-called Fermi mechanism. Despite decades of research, the Fermi acceleration process is still not understood from first principles. An assessment of the micro-physics of particle acceleration in relativistic shocks is of paramount importance to unveil the properties of astrophysical nonthermal sources, and it is the subject of this dissertation. In the first part of this thesis, I explore by means of fully-kinetic first-principle particle-in-cell (PIC) simulations the properties of relativistic shocks that propagate in electron-positron and electron-proton plasmas carrying uniform magnetic fields. I find that nonthermal particle acceleration only occurs if the upstream magnetization is weak (sigma<0.001), or if the pre-shock field is nearly aligned with the shock direction of propagation (quasi-parallel shocks). Relativistic shocks in PWNe, GRBs and AGN jets are usually thought to be appreciably magnetized (sigma>0.01) and quasi-perpendicular, yet they need to be efficient particle accelerators, in order to explain the prominent nonthermal signatures of these sources. Motivated by this discrepancy, I then relax the assumption of uniform pre-shock fields, and investigate the acceleration efficiency of perpendicular shocks that propagate in high-sigma flows with alternating magnetic fields. This is the geometry expected at the termination shock of pulsar winds, but it could also be relevant for Poynting-dominated jets in GRBs and AGNs. I show by means of PIC simulations that compression of the flow at the shock will force annihilation of nearby field lines, a process known as shock-driven reconnection. Magnetic reconnection can efficiently transfer the energy of

  9. Relativistic and non-relativistic solitons in plasmas

    NASA Astrophysics Data System (ADS)

    Barman, Satyendra Nath

    This thesis entitled as "Relativistic and Non-relativistic Solitons in Plasmas" is the embodiment of a number of investigations related to the formation of ion-acoustic solitary waves in plasmas under various physical situations. The whole work of the thesis is devoted to the studies of solitary waves in cold and warm collisionless magnetized or unmagnetized plasmas with or without relativistic effect. To analyze the formation of solitary waves in all our models of plasmas, we have employed two established methods namely - reductive perturbation method to deduce the Korteweg-de Vries (KdV) equation, the solutions of which represent the important but near exact characteristic concepts of soliton-physics. Next, the pseudopotential method to deduce the energy integral with total nonlinearity in the coupling process for exact characteristic results of solitons has been incorporated. In Chapter 1, a brief description of plasma in nature and laboratory and its generation are outlined elegantly. The nonlinear differential equations to characterize solitary waves and the relevant but important methods of solutions have been mentioned in this chapter. The formation of solitary waves in unmagnetized and magnetized plasmas, and in relativistic plasmas has been described through mathematical entity. Applications of plasmas in different fields are also put forwarded briefly showing its importance. The study of plasmas as they naturally occur in the universe encompasses number of topics including sun's corona, solar wind, planetary magnetospheres, ionospheres, auroras, cosmic rays and radiation. The study of space weather to understand the universe, communications and the activities of weather satellites are some useful areas of space plasma physics. The surface cleaning, sterilization of food and medical appliances, killing of bacteria on various surfaces, destroying of viruses, fungi, spores and plasma coating in industrial instruments ( like computers) are some of the fields

  10. The management of incidental findings of reduction mammoplasty specimens.

    PubMed

    Goodwin, Jessica T; Decroff, Chantelle; Dauway, Emilia; Sybenga, Amelia; Mahabir, Raman C

    2013-01-01

    Reduction mammoplasty is one of the most commonly performed procedures in plastic surgery. Occasionally, there are findings reported by pathologists that are unfamiliar to the treating surgeon. The aim of the present study was to determine the types of pathologies encountered in reduction mammoplasty specimens. From this list of diagnoses, a best practice guideline for management will be organized to better assist plastic surgeons in the management of patients with incidental findings on pathology reports. A total of 441 pathology reports from patients who underwent bilateral or unilateral reduction mammoplasty in the past three years were identified. A list of 21 different pathologies was generated from the pathology reports, along with supplemental data from recent texts and articles. Occult carcinomas were encountered in two cases (0.45%) and high-risk lesions were found in three cases (0.68%) at the authors' institution. An algorithm was then constructed to organize the pathologies according to risk of malignancy and assign them to a management guideline. There are many different lesions encountered incidentally in reduction mammoplasty specimens that may or may not confer some cancer risk. It is important for plastic surgeons to know which lesions need closer follow-up to provide the best care for their patients. PMID:24497763

  11. The management of incidental findings of reduction mammoplasty specimens

    PubMed Central

    Goodwin, Jessica T; DeCroff, Chantelle; Dauway, Emilia; Sybenga, Amelia; Mahabir, Raman C

    2013-01-01

    Reduction mammoplasty is one of the most commonly performed procedures in plastic surgery. Occasionally, there are findings reported by pathologists that are unfamiliar to the treating surgeon. The aim of the present study was to determine the types of pathologies encountered in reduction mammoplasty specimens. From this list of diagnoses, a best practice guideline for management will be organized to better assist plastic surgeons in the management of patients with incidental findings on pathology reports. A total of 441 pathology reports from patients who underwent bilateral or unilateral reduction mammoplasty in the past three years were identified. A list of 21 different pathologies was generated from the pathology reports, along with supplemental data from recent texts and articles. Occult carcinomas were encountered in two cases (0.45%) and high-risk lesions were found in three cases (0.68%) at the authors’ institution. An algorithm was then constructed to organize the pathologies according to risk of malignancy and assign them to a management guideline. There are many different lesions encountered incidentally in reduction mammoplasty specimens that may or may not confer some cancer risk. It is important for plastic surgeons to know which lesions need closer follow-up to provide the best care for their patients. PMID:24497763

  12. Anxiety perseverance in intergroup interaction: When incidental explanations backfire.

    PubMed

    West, Tessa V; Pearson, Adam R; Stern, Chadly

    2014-11-01

    Intergroup interactions are often anxiety provoking, and this can lead members of both majority and minority groups to avoid contact. Whereas negative consequences of experiencing intergroup anxiety are well documented, the role of perceived anxiety has received substantially less theoretical and empirical attention. We demonstrate in 3 experiments that the perception of anxiety in others can undermine intergroup interactions even when the anxiety can be attributed to a source that is unrelated to the interaction. Participants who learned that a cross-race partner's anxiety could be attributed to an upcoming evaluation (Study 1) or a stimulant (i.e., caffeine, Studies 2 and 3) expressed less interest in continuing an interaction (Studies 1 and 2), showed less self-disclosure (Study 2), and increased physical distance between themselves and their partner (Study 3) than did those given no source information and participants who interacted with a same-race partner. Moreover, compared to control participants, perceivers who were given an incidental explanation for their partner's anxiety perceived outgroup, but not ingroup, partners as more anxious (Studies 1 and 3) and showed heightened accessibility of anxiety words (Study 3), indicating that incidental source information enhanced accessibility of intergroup (but not intragroup) anxiety at early stages of information processing. Theoretical and practical implications for combating paradoxical effects of perceived anxiety in intergroup interactions are considered.

  13. Small Renal Masses: Incidental Diagnosis, Clinical Symptoms, and Prognostic Factors

    PubMed Central

    Sánchez-Martín, F. M.; Millán-Rodríguez, F.; Urdaneta-Pignalosa, G.; Rubio-Briones, J.; Villavicencio-Mavrich, H.

    2008-01-01

    Introduction. The small renal masses (SRMs) have increased over the past two decades due to more liberal use of imaging techniques. SRMs have allowed discussions regarding their prognostic, diagnosis, and therapeutic approach. Materials and methods. Clinical presentation, incidental diagnosis, and prognosis factors of SRMs are discussed in this review. Results. SRMs are defined as lesions less than 4 cm in diameter. SRM could be benign, and most malignant SMRs are low stage and low grade. Clinical symptoms like hematuria are very rare, being diagnosed by chance (incidental) in most cases. Size, stage, and grade are still the most consistent prognosis factors in (RCC). An enhanced contrast SRM that grows during active surveillance is clearly malignant, and its aggressive potential increases in those greater than 3 cm. Clear cell carcinoma is the most frequent cellular type of malign SRM. Conclusions. Only some SRMs are benign. The great majority of malign SRMs have good prognosis (low stage and grade, no metastasis) with open or laparoscopic surgical treatment (nephron sparing techniques). Active surveillance is an accepted attitude in selected cases. PMID:19165347

  14. Incidental Medical Information in Whole-Exome Sequencing

    PubMed Central

    Hadley, Donald W.; Pineda-Alvarez, Daniel E.; Kamat, Aparna; Teer, Jamie K.; Cherukuri, Praveen F.; Hansen, Nancy F.; Cruz, Pedro; Young, Alice C.; Berkman, Benjamin E.; Chandrasekharappa, Settara C.; Mullikin, James C.

    2012-01-01

    Genomic technologies, such as whole-exome sequencing, are a powerful tool in genetic research. Such testing yields a great deal of incidental medical information, or medical information not related to the primary research target. We describe the management of incidental medical information derived from whole-exome sequencing in the research context. We performed whole-exome sequencing on a monozygotic twin pair in which only 1 child was affected with congenital anomalies and applied an institutional review board–approved algorithm to determine what genetic information would be returned. Whole-exome sequencing identified 79 525 genetic variants in the twins. Here, we focus on novel variants. After filtering artifacts and excluding known single nucleotide polymorphisms and variants not predicted to be pathogenic, the twins had 32 novel variants in 32 genes that were felt to be likely to be associated with human disease. Eighteen of these novel variants were associated with recessive disease and 18 were associated with dominantly manifesting conditions (variants in some genes were potentially associated with both recessive and dominant conditions), but only 1 variant ultimately met our institutional review board–approved criteria for return of information to the research participants. PMID:22585771

  15. Computed Tomography Features of Incidentally Detected Diffuse Thyroid Disease

    PubMed Central

    Rho, Myung Ho

    2014-01-01

    Objective. This study aimed to evaluate the CT features of incidentally detected DTD in the patients who underwent thyroidectomy and to assess the diagnostic accuracy of CT diagnosis. Methods. We enrolled 209 consecutive patients who received preoperative neck CT and subsequent thyroid surgery. Neck CT in each case was retrospectively investigated by a single radiologist. We evaluated the diagnostic accuracy of individual CT features and the cut-off CT criteria for detecting DTD by comparing the CT features with histopathological results. Results. Histopathological examination of the 209 cases revealed normal thyroid (n = 157), Hashimoto thyroiditis (n = 17), non-Hashimoto lymphocytic thyroiditis (n = 34), and diffuse hyperplasia (n = 1). The CT features suggestive of DTD included low attenuation, inhomogeneous attenuation, increased glandular size, lobulated margin, and inhomogeneous enhancement. ROC curve analysis revealed that CT diagnosis of DTD based on the CT classification of “3 or more” abnormal CT features was superior. When the “3 or more” CT classification was selected, the sensitivity, specificity, positive and negative predictive values, and accuracy of CT diagnosis for DTD were 55.8%, 95.5%, 80.6%, 86.7%, and 85.6%, respectively. Conclusion. Neck CT may be helpful for the detection of incidental DTD. PMID:25548565

  16. Word imageability and N400 in an incidental memory paradigm.

    PubMed

    Nittono, Hiroshi; Suehiro, Maki; Hori, Tadao

    2002-06-01

    High imagery words are memorized better than low imagery words. To examine how these words are processed at encoding, event-related potentials (ERPs) were recorded in an incidental memory paradigm. Frequency-matched high and low imagery words (45 words each) were presented in a random order on a computer screen. Twelve university students were asked to rate the imageability of a word's referent on a five-point scale. High imagery words elicited a larger N400 than low imagery words did. The N400 was more left-lateralized for low imagery words than for high imagery words, suggesting that some neural generators (probably in the right hemisphere) were not involved in the processing of low imagery words. Difference waveforms showed that the N400 was followed by a second negativity (N800), which was also larger for high imagery words and had a scalp distribution similar to that of the N400. Subsequent free recall showed a classical imagery effect that high imagery words were recalled better than low imagery words. These results suggest that the superiority of high imagery words over low imagery words in incidental memory results from more extensive activation of a semantic network distributed across the left and right hemispheres, the latter of which probably deals with imagery-related information that is not activated by low imagery words. PMID:12031296

  17. Unexpected but Incidental Positive Outcomes Predict Real-World Gambling.

    PubMed

    Otto, A Ross; Fleming, Stephen M; Glimcher, Paul W

    2016-03-01

    Positive mood can affect a person's tendency to gamble, possibly because positive mood fosters unrealistic optimism. At the same time, unexpected positive outcomes, often called prediction errors, influence mood. However, a linkage between positive prediction errors-the difference between expected and obtained outcomes-and consequent risk taking has yet to be demonstrated. Using a large data set of New York City lottery gambling and a model inspired by computational accounts of reward learning, we found that people gamble more when incidental outcomes in the environment (e.g., local sporting events and sunshine) are better than expected. When local sports teams performed better than expected, or a sunny day followed a streak of cloudy days, residents gambled more. The observed relationship between prediction errors and gambling was ubiquitous across the city's socioeconomically diverse neighborhoods and was specific to sports and weather events occurring locally in New York City. Our results suggest that unexpected but incidental positive outcomes influence risk taking. PMID:26796614

  18. 78 FR 24161 - Takes of Marine Mammals Incidental to Specified Activities; Navy Training Conducted at the Silver...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-24

    .... ACTION: Notice; proposed incidental harassment authorization; request for comments. SUMMARY: NMFS has received a complete application from the U.S. Navy (Navy) for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to conducting training exercises at the...

  19. 77 FR 19231 - Takes of Marine Mammals Incidental to Specified Activities; Navy Training Conducted at the Silver...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-30

    .... ACTION: Notice; additional information for the proposed incidental harassment authorization; request for comments. SUMMARY: NMFS has received an application from the U.S. Navy (Navy) for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to conducting training exercises at...

  20. 12 CFR 1501.2 - What activities has the Secretary determined to be financial in nature or incidental to a...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... to be financial in nature or incidental to a financial activity? 1501.2 Section 1501.2 Banks and... the Secretary determined to be financial in nature or incidental to a financial activity? (a... following types of activities are financial in nature or incidental to a financial activity when...

  1. 12 CFR 1501.2 - What activities has the Secretary determined to be financial in nature or incidental to a...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... be financial in nature or incidental to a financial activity? 1501.2 Section 1501.2 Banks and Banking... Secretary determined to be financial in nature or incidental to a financial activity? (a) Activities... of activities are financial in nature or incidental to a financial activity when conducted...

  2. 12 CFR 1501.2 - What activities has the Secretary determined to be financial in nature or incidental to a...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... be financial in nature or incidental to a financial activity? 1501.2 Section 1501.2 Banks and Banking... Secretary determined to be financial in nature or incidental to a financial activity? (a) Activities... of activities are financial in nature or incidental to a financial activity when conducted...

  3. 12 CFR 1501.2 - What activities has the Secretary determined to be financial in nature or incidental to a...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... be financial in nature or incidental to a financial activity? 1501.2 Section 1501.2 Banks and Banking... Secretary determined to be financial in nature or incidental to a financial activity? (a) Activities... of activities are financial in nature or incidental to a financial activity when conducted...

  4. 12 CFR 1501.2 - What activities has the Secretary determined to be financial in nature or incidental to a...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... be financial in nature or incidental to a financial activity? 1501.2 Section 1501.2 Banks and Banking... Secretary determined to be financial in nature or incidental to a financial activity? (a) Activities... of activities are financial in nature or incidental to a financial activity when conducted...

  5. Relativistic Corrections to the Bohr Model of the Atom

    ERIC Educational Resources Information Center

    Kraft, David W.

    1974-01-01

    Presents a simple means for extending the Bohr model to include relativistic corrections using a derivation similar to that for the non-relativistic case, except that the relativistic expressions for mass and kinetic energy are employed. (Author/GS)

  6. Magnetogenesis through Relativistic Velocity Shear

    NASA Astrophysics Data System (ADS)

    Miller, Evan

    Magnetic fields at all scales are prevalent in our universe. However, current cosmological models predict that initially the universe was bereft of large-scale fields. Standard magnetohydrodynamics (MHD) does not permit magnetogenesis; in the MHD Faraday's law, the change in magnetic field B depends on B itself. Thus if B is initially zero, it will remain zero for all time. A more accurate physical model is needed to explain the origins of the galactic-scale magnetic fields observed today. In this thesis, I explore two velocity-driven mechanisms for magnetogenesis in 2-fluid plasma. The first is a novel kinematic 'battery' arising from convection of vorticity. A coupling between thermal and plasma oscillations, this non-relativistic mechanism can operate in flows that are incompressible, quasi-neutral and barotropic. The second mechanism results from inclusion of thermal effects in relativistic shear flow instabilities. In such flows, parallel perturbations are ubiquitously unstable at small scales, with growth rates of order with the plasma frequency over a defined range of parameter-space. Of these two processes, instabilities seem far more likely to account for galactic magnetic fields. Stable kinematic effects will, at best, be comparable to an ideal Biermann battery, which is suspected to be orders of magnitude too weak to produce the observed galactic fields. On the other hand, instabilities grow until saturation is reached, a topic that has yet to be explored in detail on cosmological scales. In addition to investigating these magnetogenesis sources, I derive a general dispersion relation for three dimensional, warm, two species plasma with discontinuous shear flow. The mathematics of relativistic plasma, sheared-flow instability and the Biermann battery are also discussed.

  7. Relativistic electromagnetic ion cyclotron instabilities.

    PubMed

    Chen, K R; Huang, R D; Wang, J C; Chen, Y Y

    2005-03-01

    The relativistic instabilities of electromagnetic ion cyclotron waves driven by MeV ions are analytically and numerically studied. As caused by wave magnetic field and in sharp contrast to the electrostatic case, interesting characteristics such as Alfve nic behavior and instability transition are discovered and illuminated in detail. The instabilities are reactive and are raised from the coupling of slow ions' first-order resonance and fast ions' second-order resonance, that is an essential extra mechanism due to relativistic effect. Because of the wave magnetic field, the nonresonant plasma dielectric is usually negative and large, that affects the instability conditions and scaling laws. A negative harmonic cyclotron frequency mismatch between the fast and slow ions is required for driving a cubic (and a coupled quadratic) instability; the cubic (square) root scaling of the peak growth rate makes the relativistic effect more important than classical mechanism, especially for low fast ion density and Lorentz factor being close to unity. For the cubic instability, there is a threshold (ceiling) on the slow ion temperature and density (the external magnetic field and the fast ion energy); the Alfve n velocity is required to be low. This Alfve nic behavior is interesting in physics and important for its applications. The case of fast protons in thermal deuterons is numerically studied and compared with the analytical results. When the slow ion temperature or density (the external magnetic field or the fast ion energy) is increased (reduced) to about twice (half) the threshold (ceiling), the same growth rate peak transits from the cubic instability to the coupled quadratic instability and a different cubic instability branch appears. The instability transition is an interesting new phenomenon for instability. PMID:15903591

  8. Relativistic radiative transfer and relativistic spherical shell flows

    NASA Astrophysics Data System (ADS)

    Fukue, Jun

    2016-06-01

    We examine a radiatively driven spherical flow from a central object, whose thickness is smaller than the radius of the central object, and a plane-parallel approximation can be used-a spherical shell flow. We first solve the relativistic radiative transfer equation iteratively, using a given velocity field, and obtain specific intensities as well as moment quantities. Using the obtained comoving flux, we then solve the relativistic hydrodynamical equation, and obtain a new velocity field. We repeat these double iteration processes until both the intensity and velocity profiles converge. We found that the flow speed v(τ) is roughly approximated as β ≡ v/c = βs(1 - τ/τb), where τ is the optical depth, τb the flow total optical depth, and c the speed of light. We further found that the flow terminal speed vs is roughly expressed as β _s ≡ v_s/c = (Γ hat{F}_0-1)τ_b/dot{m} , where Γ is the central luminosity normalized by the Eddington luminosity, hat{F}_0 the comoving flux normalized by the incident flux, and of the order of unity, and dot{m} the mass-loss rate normalized by the critical mass loss.

  9. External inverse-Compton emission from jetted tidal disruption events

    NASA Astrophysics Data System (ADS)

    Lu, Wenbin; Kumar, Pawan

    2016-05-01

    The recent discoveries of Sw J1644+57 and Sw J2058+05 show that tidal disruption events (TDEs) can launch relativistic jets. Super-Eddington accretion produces a strong radiation field of order Eddington luminosity. In a jetted TDE, electrons in the jet will inverse-Compton scatter the photons from the accretion disc and wind (external radiation field). Motivated by observations of thermal optical-UV spectra in Sw J2058+05 and several other TDEs, we assume the spectrum of the external radiation field intercepted by the relativistic jet to be blackbody. Hot electrons in the jet scatter this thermal radiation and produce luminosities 1045-1048 erg s- 1 in the X/γ-ray band. This model of thermal plus inverse-Compton radiation is applied to Sw J2058+05. First, we show that the blackbody component in the optical-UV spectrum most likely has its origin in the super-Eddington wind from the disc. Then, using the observed blackbody component as the external radiation field, we show that the X-ray luminosity and spectrum are consistent with the inverse-Compton emission, under the following conditions: (1) the jet Lorentz factor is Γ ≃ 5-10; (2) electrons in the jet have a power-law distribution dN_e/dγ _e ∝ γ _e^{-p} with γmin ˜ 1 and p = 2.4; (3) the wind is mildly relativistic (Lorentz factor ≳ 1.5) and has isotropic-equivalent mass-loss rate ˜ 5 M⊙ yr- 1. We describe the implications for jet composition and the radius where jet energy is converted to radiation.

  10. Thermodynamics of polarized relativistic matter

    NASA Astrophysics Data System (ADS)

    Kovtun, Pavel

    2016-07-01

    We give the free energy of equilibrium relativistic matter subject to external gravitational and electromagnetic fields, to one-derivative order in the gradients of the external fields. The free energy allows for a straightforward derivation of bound currents and bound momenta in equilibrium. At leading order, the energy-momentum tensor admits a simple expression in terms of the polarization tensor. Beyond the leading order, electric and magnetic polarization vectors are intrinsically ambiguous. The physical effects of polarization, such as the correlation between the magneto-vortically induced surface charge and the electro-vortically induced surface current, are not ambiguous.

  11. Relativistic atomic beam spectroscopy II

    SciTech Connect

    1989-12-31

    The negative ion of H is one of the simplest 3-body atomic systems. The techniques we have developed for experimental study of atoms moving near speed of light have been productive. This proposal request continuing support for experimental studies of the H{sup -} system, principally at the 800 MeV linear accelerator (LAMPF) at Los Alamos. Four experiments are currently planned: photodetachment of H{sup -} near threshold in electric field, interaction of relativistic H{sup -} ions with matter, high excitations and double charge escape in H{sup -}, and multiphoton detachment of electrons from H{sup -}.

  12. Relativistic mean-field theory

    NASA Astrophysics Data System (ADS)

    Meng, Jie; Ring, Peter; Zhao, Pengwei

    In this chapter, the covariant energy density functional is constructed with both the meson-exchange and the point-coupling pictures. Several widely used functionals with either nonlinear or density-dependent effective interactions are introduced. The applications of covariant density functional theory are demonstrated for infinite nuclear matter and finite nuclei with spherical symmetry, axially symmetric quadrupole deformation, and triaxial quadrupole shapes. Finally, a relativistic description of the nuclear landscape has been discussed, which is not only important for nuclear structure, but also important for nuclear astrophysics, where we are facing the problem of a reliable extrapolation to the very neutron-rich nuclei.

  13. Adaptive wavelets and relativistic magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Hirschmann, Eric; Neilsen, David; Anderson, Matthe; Debuhr, Jackson; Zhang, Bo

    2016-03-01

    We present a method for integrating the relativistic magnetohydrodynamics equations using iterated interpolating wavelets. Such provide an adaptive implementation for simulations in multidimensions. A measure of the local approximation error for the solution is provided by the wavelet coefficients. They place collocation points in locations naturally adapted to the flow while providing expected conservation. We present demanding 1D and 2D tests includingthe Kelvin-Helmholtz instability and the Rayleigh-Taylor instability. Finally, we consider an outgoing blast wave that models a GRB outflow.

  14. Relativistic quantum private database queries

    NASA Astrophysics Data System (ADS)

    Sun, Si-Jia; Yang, Yu-Guang; Zhang, Ming-Ou

    2015-04-01

    Recently, Jakobi et al. (Phys Rev A 83, 022301, 2011) suggested the first practical private database query protocol (J-protocol) based on the Scarani et al. (Phys Rev Lett 92, 057901, 2004) quantum key distribution protocol. Unfortunately, the J-protocol is just a cheat-sensitive private database query protocol. In this paper, we present an idealized relativistic quantum private database query protocol based on Minkowski causality and the properties of quantum information. Also, we prove that the protocol is secure in terms of the user security and the database security.

  15. Einstein Toolkit for Relativistic Astrophysics

    NASA Astrophysics Data System (ADS)

    Collaborative Effort

    2011-02-01

    The Einstein Toolkit is a collection of software components and tools for simulating and analyzing general relativistic astrophysical systems. Such systems include gravitational wave space-times, collisions of compact objects such as black holes or neutron stars, accretion onto compact objects, core collapse supernovae and Gamma-Ray Bursts. The Einstein Toolkit builds on numerous software efforts in the numerical relativity community including CactusEinstein, Whisky, and Carpet. The Einstein Toolkit currently uses the Cactus Framework as the underlying computational infrastructure that provides large-scale parallelization, general computational components, and a model for collaborative, portable code development.

  16. Relativistic kinematics and stationary motions

    NASA Astrophysics Data System (ADS)

    Russo, Jorge G.; Townsend, Paul K.

    2009-11-01

    The relativistic jerk, snap and all higher-order kinematical D-vectors are defined for the motion of a massive particle in a D-dimensional Minkowski spacetime. We illustrate the formalism with stationary motions, for which we provide a new, Lorentz covariant, classification. We generalize some cases to branes, explaining the relevance to uniform motion in a heat bath. We also consider some non-stationary motions, including motion with constant proper jerk, and free fall into a black hole as viewed from a GEMS perspective.

  17. Incidental Magnetization Transfer Contrast by Fat Saturation Preparation Pulses in Multi-slice Look-Locker Echo Planar Imaging: Modulation of Signal Intensity and Bias on T1 Measurement

    PubMed Central

    Shin, Wanyong; Gu, Hong; Yang, Yihong

    2009-01-01

    In this study, it is demonstrated that fat saturation (FS) preparation (prep) pulses generate incidental magnetization transfer contrast (MTC) in multi-slice Look-Locker imaging. It is shown that frequency-selective FS prep pulses can invoke MTC through the exchange between free and motion-restricted protons. Simulation reveals that the fractional signal loss by these MTC effects is more severe for smaller flip angles, shorter repetition times, and greater number of slices. These incidental MTC effects result in a signal attenuation at a steady state (up to 30%) and a T1 measurement bias (up to 20%) when using inversion recovery Look-Locker EPI sequences. Furthermore, it is shown that water-selective MR imaging using binominal pulses has the potential to minimize the signal attenuation and provide unbiased T1 measurement without fat artifacts in MR images. PMID:19526506

  18. Magnetism and rotation in relativistic field theory

    NASA Astrophysics Data System (ADS)

    Mameda, Kazuya; Yamamoto, Arata

    2016-09-01

    We investigate the analogy between magnetism and rotation in relativistic theory. In nonrelativistic theory, the exact correspondence between magnetism and rotation is established in the presence of an external trapping potential. Based on this, we analyze relativistic rotation under external trapping potentials. A Landau-like quantization is obtained by considering an energy-dependent potential.

  19. Compton Effect with Non-Relativistic Kinematics

    ERIC Educational Resources Information Center

    Shivalingaswamy, T.; Kagali, B. A.

    2011-01-01

    In deducing the change of wavelength of x-rays scattered by atomic electrons, one normally makes use of relativistic kinematics for electrons. However, recoiling energies of the electrons are of the order of a few keV which is less than 0.2% of their rest energies. Hence the authors may ask whether relativistic formulae are really necessary. In…

  20. Einstein Never Approved of Relativistic Mass

    ERIC Educational Resources Information Center

    Hecht, Eugene

    2009-01-01

    During much of the 20th century it was widely believed that one of the significant insights of special relativity was "relativistic mass." Today there are two schools on that issue: the traditional view that embraces speed-dependent "relativistic mass," and the more modern position that rejects it, maintaining that there is only one mass and it's…

  1. Nonlinear, relativistic Langmuir waves in astrophysical magnetospheres

    NASA Technical Reports Server (NTRS)

    Chian, Abraham C.-L.

    1987-01-01

    Large amplitude, electrostatic plasma waves are relevant to physical processes occurring in the astrophysical magnetospheres wherein charged particles are accelerated to relativistic energies by strong waves emitted by pulsars, quasars, or radio galaxies. The nonlinear, relativistic theory of traveling Langmuir waves in a cold plasma is reviewed. The cases of streaming electron plasma, electronic plasma, and two-streams are discussed.

  2. Inversion of triton moments

    NASA Astrophysics Data System (ADS)

    Clare, R. B.; Levinger, J. S.

    1981-02-01

    We use the formalism of hyperspherical harmonics to calculate several moments for the triton photoeffect, for a Volkov spin-independent potential. First, we improve the accuracy of Maleki's calculations of the moments σ2 and σ3 by including more terms in the hyperspherical expansion. We also calculate moments σ0 and σ1 for a Serber mixture. We find reasonable agreement between our moments found by sum rules and those found from the cross sections calculated by Fang et al. and Levinger-Fitzgibbon. We then develop a technique of inversion of a finite number of moments by making the assumption that the cross section can be written as a sum of several Laguerre polynomials multiplied by a decreasing exponential. We test our inversion technique successfully on several model potentials. We then modify it and apply it to the five moments (σ-1 to σ3) for a force without exchange, and find fair agreement with Fang's values of the cross section. Finally, we apply the inversion technique to our three moments (σ-1,σ0,and σ1) for a Serber mixture, and find reasonable agreement with Gorbunov's measurements of the 3He photoeffect. NUCLEAR REACTIONS Triton photoeffects, hyperspherical harmonics, moments of photoeffect, inversion of moments.

  3. Weak decays of the B c meson to B s and B mesonsin the relativistic quark model

    NASA Astrophysics Data System (ADS)

    Ebert, D.; Faustov, R. N.; Galkin, V. O.

    2003-12-01

    Semileptonic and non-leptonic decays of the B c meson to B s and B mesons, caused by the cto s,d quark transitions, are studied in the framework of the relativistic quark model. The heavy quark expansion in inverse powers of the active c and spectator bar b quark is used to simplify calculations while the final s and d quarks in the B s and B mesons are treated relativistically. The decay form factors are explicitly expressed through the overlap integrals of the meson wave functions in the whole accessible kinematical range. The obtained results are compared with the predictions of other approaches.

  4. Relativistic Definition of Spin Operators

    NASA Astrophysics Data System (ADS)

    Ryder, Lewis H.

    2002-12-01

    Some years ago Mashhoon [1] made the highly interesting suggestion that there existed a coupling of spin with rotations, just as there exists such a coupling with orbital angular momentum, as seen in the Sagnac effect, for example. Spin being essentially a quantum phenomenon, the obvious place to look for this was by studying the Dirac equation, and Hehl and Ni, in such an investigation [2], indeed found a coupling term of just the type Mashhoon had envisaged. Part of their procedure, however, was to take the nonrelativistic limit, and this was done by performing appropriate Foldy-Wouthuysen (FW) transformations. In the nonrelativistic limit, it is well-known that the spin operators for Dirac particles are in essence the Pauli matrices; but it is also well-known, and indeed was part of the motivation for Foldy and Wouthuysen's paper, that for fully-fledged Dirac particles the (4×4 generalisation of the) Pauli matrices do not yield satisfactory spin operators, since spin defined in this way would not be conserved. The question therefore presented itself: is there a relativistic spin operator for Dirac particles, such that in the relativistic, as well as the nonrelativistic, régime a Mashhoon spin-rotation coupling exists?...

  5. Single electron relativistic clock interferometer

    NASA Astrophysics Data System (ADS)

    Bushev, P. A.; Cole, J. H.; Sholokhov, D.; Kukharchyk, N.; Zych, M.

    2016-09-01

    Although time is one of the fundamental notions in physics, it does not have a unique description. In quantum theory time is a parameter ordering the succession of the probability amplitudes of a quantum system, while according to relativity theory each system experiences in general a different proper time, depending on the system's world line, due to time dilation. It is therefore of fundamental interest to test the notion of time in the regime where both quantum and relativistic effects play a role, for example, when different amplitudes of a single quantum clock experience different magnitudes of time dilation. Here we propose a realization of such an experiment with a single electron in a Penning trap. The clock can be implemented in the electronic spin precession and its time dilation then depends on the radial (cyclotron) state of the electron. We show that coherent manipulation and detection of the electron can be achieved already with present day technology. A single electron in a Penning trap is a technologically ready platform where the notion of time can be probed in a hitherto untested regime, where it requires a relativistic as well as quantum description.

  6. 24-Hour Relativistic Bit Commitment

    NASA Astrophysics Data System (ADS)

    Verbanis, Ephanielle; Martin, Anthony; Houlmann, Raphaël; Boso, Gianluca; Bussières, Félix; Zbinden, Hugo

    2016-09-01

    Bit commitment is a fundamental cryptographic primitive in which a party wishes to commit a secret bit to another party. Perfect security between mistrustful parties is unfortunately impossible to achieve through the asynchronous exchange of classical and quantum messages. Perfect security can nonetheless be achieved if each party splits into two agents exchanging classical information at times and locations satisfying strict relativistic constraints. A relativistic multiround protocol to achieve this was previously proposed and used to implement a 2-millisecond commitment time. Much longer durations were initially thought to be insecure, but recent theoretical progress showed that this is not so. In this Letter, we report on the implementation of a 24-hour bit commitment solely based on timed high-speed optical communication and fast data processing, with all agents located within the city of Geneva. This duration is more than 6 orders of magnitude longer than before, and we argue that it could be extended to one year and allow much more flexibility on the locations of the agents. Our implementation offers a practical and viable solution for use in applications such as digital signatures, secure voting and honesty-preserving auctions.

  7. Non-relativistic scale anomalies

    NASA Astrophysics Data System (ADS)

    Arav, Igal; Chapman, Shira; Oz, Yaron

    2016-06-01

    We extend the cohomological analysis in arXiv:1410.5831 of anisotropic Lifshitz scale anomalies. We consider non-relativistic theories with a dynamical critical exponent z = 2 with or without non-relativistic boosts and a particle number symmetry. We distinguish between cases depending on whether the time direction does or does not induce a foliation structure. We analyse both 1 + 1 and 2 + 1 spacetime dimensions. In 1 + 1 dimensions we find no scale anomalies with Galilean boost symmetries. The anomalies in 2 + 1 dimensions with Galilean boosts and a foliation structure are all B-type and are identical to the Lifshitz case in the purely spatial sector. With Galilean boosts and without a foliation structure we find also an A-type scale anomaly. There is an infinite ladder of B-type anomalies in the absence of a foliation structure with or without Galilean boosts. We discuss the relation between the existence of a foliation structure and the causality of the field theory.

  8. Stabilization effect of Weibel modes in relativistic laser fusion plasma

    NASA Astrophysics Data System (ADS)

    Belghit, Slimen; Sid, Abdelaziz

    2016-06-01

    In this work, the Weibel instability (WI) due to inverse bremsstrahlung (IB) absorption in a laser fusion plasma has been investigated. The stabilization effect due to the coupling of the self-generated magnetic field by WI with the laser wave field is explicitly shown. In this study, the relativistic effects are taken into account. Here, the basic equation is the relativistic Fokker-Planck (F-P) equation. The main obtained result is that the coupling of self-generated magnetic field with the laser wave causes a stabilizing effect of excited Weibel modes. We found a decrease in the spectral range of Weibel unstable modes. This decreasing is accompanied by a reduction of two orders in the growth rate of instable Weibel modes or even stabilization of these modes. It has been shown that the previous analysis of the Weibel instability due to IB has overestimated the values of the generated magnetic fields. Therefore, the generation of magnetic fields by the WI due to IB should not affect the experiences of an inertial confinement fusion.

  9. Minimally implicit Runge-Kutta methods for Resistive Relativistic MHD

    NASA Astrophysics Data System (ADS)

    Aloy, Miguel-Á.; Cordero-Carrión, Isabel

    2016-05-01

    The Relativistic Resistive Magnetohydrodynamic (RRMHD) equations are a hyperbolic system of partial differential equations used to describe the dynamics of relativistic magnetized fluids with a finite conductivity. Close to the ideal magnetohydrodynamic regime, the source term proportional to the conductivity becomes potentially stiff and cannot be handled with standard explicit time integration methods. We propose a new class of methods to deal with the stiffness fo the system, which we name Minimally Implicit Runge-Kutta methods. These methods avoid the development of numerical instabilities without increasing the computational costs in comparison with explicit methods, need no iterative extra loop in order to recover the primitive (physical) variables, the analytical inversion of the implicit operator is trivial and the several stages can actually be viewed as stages of explicit Runge-Kutta methods with an effective time-step. We test these methods with two different one-dimensional test beds in varied conductivity regimes, and show that our second-order schemes satisfy the theoretical expectations.

  10. Relativistic electron and ion dust charging currents

    SciTech Connect

    Tribeche, Mouloud; Boukhalfa, Soufiane

    2009-09-15

    A first theoretical attempt is made to present a relativistic generalization of the well-known orbit-limited motion theory. The appropriate relativistic (electron and ion) dust charging currents are derived. The nonlinear electrostatic potential is then expressed in terms of the variable dust charge and we take advantage of this new transcendental relation to investigate briefly the effects of relativistic charge carriers. As the relativistic character of the plasma increases, it becomes evident that certain negative values of the dust charge can never be achieved as increasingly larger values of the nonlinear potential are involved. The obtained formulas bring a possibility to build theories of nonlinear collective process in relativistic dusty plasmas.

  11. Incidental radiographic finding of the concealed art of susuk.

    PubMed

    Devang Divakar, Darshan; Mavinapalla, Seema; Al Kheraif, Abdulaziz Abdullah; Ramakrishnaiah, Ravikumar; Abd Rahim, Muhammad Furqon Bin; Khan, Aftab Ahmed

    2016-07-01

    Susuk, or charm needles, are small, metallic needles inserted under the skin, considered to enhance beauty, health and luck. This hidden secret of inserting susuk is a traditional superstitious ritual, widely practiced among women of Southeast Asia. Here, we present an interesting case of incidental radiographic finding of the concealed art of susuk, which was exposed on a panoramic radiograph taken on a routine basis as a part of diagnostic work up at our centre. An orthopantomogram revealed bilateral metallic foreign bodies in the maxillo-facial region. Anamnestic data affirmed the practice of the body art of susuk. The charm needles were present in the orofacial region without the patient experiencing any pathological signs or symptoms.

  12. Adrenal Pheochromocytoma Incidentally Discovered in a Patient With Parkinsonism

    PubMed Central

    Petramala, Luigi; Concistrè, Antonio; Marinelli, Cristiano; Zinnamosca, Laura; Iannucci, Gino; Lucia, Piernatale; De Vincentis, Giuseppe; Letizia, Claudio

    2015-01-01

    Abstract To evaluate the diagnostic route of pheochromocytoma (PHEO) in a patient under dopaminergic treatment. A 70-year-old man with Parkinsonism and under treatment with levodopa and carbidopa came to our observation for evaluation of arterial hypertension and right adrenal mass discovered incidentally. To evaluate adrenal hormone levels we performed a dexamethasone suppression test, plasma aldosterone levels and 24-hr urinary metanephrine, which revealed elevated levels of catecholamines metabolities. 123-I-metaiodobenzylguanidine SPECT scintiscan revealed raised activity within the right adrenal gland concordant with the mass. The diagnosis of PHEO was posed and an elective laparoscopic adrenalectomy was performed; histopathological examination confirmed the PHEO diagnosis. Recently the coexistence of PHEO and Parkinsonism is a very rare association of diseases, with only 3 cases reported in literature. In this article, another case is reported and diagnostic procedures are discussed. PMID:26496334

  13. Breast Sparganosis Incidentally Detected by FDG PET/CT.

    PubMed

    Ha, Seunggyun; Oh, So Won; Kim, Yu Kyeong; Yi, Ann; Ahn, Young Joon

    2013-06-01

    Sparganosis is a rare, parasitic infection that is caused by the plercercoid tapeworm larvae of the genus Spirometra. Sparganosis is transmitted by ingestion of larvae-containing water or intermediate hosts, such as raw amphibians, and usually presented with a subcutaneous nodule in the abdominal wall, extremities, and genital organs. Among the various involved organs, the breast is a seldom encountered site for sparganosis. However, breast sparganosis has clinical importance, since it is generally presented with an indolent palpable mass that mimics malignancy, even without evidence of inflammation. Herein, we report a case of breast sparganosis that was detected incidentally by FDG PET/CT during staging work ups in a patient with gall bladder cancer. PMID:24900094

  14. Self-corrected elaboration and spacing effects in incidental memory.

    PubMed

    Toyota, Hiroshi

    2006-04-01

    The present study investigated the effect of self-corrected elaboration on incidental memory as a function of types of presentation (massed vs spaced) and sentence frames (image vs nonimage). The subjects were presented a target word and an incongruous sentence frame and asked to correct the target to make a common sentence in the self-corrected elaboration condition, whereas in the experimenter-corrected elaboration condition they were asked to rate the appropriateness of the congruous word presented, followed by free recall test. The superiority of the self-corrected elaboration to the experimenter-corrected elaboration was observed only in some situations of combinations by the types of presentation and sentence frames. These results were discussed in terms of the effectiveness of the self-corrected elaboration. PMID:16826672

  15. Incidental radiographic finding of the concealed art of susuk.

    PubMed

    Devang Divakar, Darshan; Mavinapalla, Seema; Al Kheraif, Abdulaziz Abdullah; Ramakrishnaiah, Ravikumar; Abd Rahim, Muhammad Furqon Bin; Khan, Aftab Ahmed

    2016-07-01

    Susuk, or charm needles, are small, metallic needles inserted under the skin, considered to enhance beauty, health and luck. This hidden secret of inserting susuk is a traditional superstitious ritual, widely practiced among women of Southeast Asia. Here, we present an interesting case of incidental radiographic finding of the concealed art of susuk, which was exposed on a panoramic radiograph taken on a routine basis as a part of diagnostic work up at our centre. An orthopantomogram revealed bilateral metallic foreign bodies in the maxillo-facial region. Anamnestic data affirmed the practice of the body art of susuk. The charm needles were present in the orofacial region without the patient experiencing any pathological signs or symptoms. PMID:26271077

  16. Self-corrected elaboration and spacing effects in incidental memory.

    PubMed

    Toyota, Hiroshi

    2006-04-01

    The present study investigated the effect of self-corrected elaboration on incidental memory as a function of types of presentation (massed vs spaced) and sentence frames (image vs nonimage). The subjects were presented a target word and an incongruous sentence frame and asked to correct the target to make a common sentence in the self-corrected elaboration condition, whereas in the experimenter-corrected elaboration condition they were asked to rate the appropriateness of the congruous word presented, followed by free recall test. The superiority of the self-corrected elaboration to the experimenter-corrected elaboration was observed only in some situations of combinations by the types of presentation and sentence frames. These results were discussed in terms of the effectiveness of the self-corrected elaboration.

  17. Incidental gastric glomus tumor after laparoscopic sleeve gastrectomy

    PubMed Central

    Oruç, Mehmet Tahir; Aslaner, Arif; Çekiç, Sema; Sakar, Alkan; Yardimci, Erdem Can

    2016-01-01

    Gastric glomus tumors (GGTs) are unusual benign, subepithelial, mesenchymal neoplasms of modified smooth muscle cells representing a neoplastic counterpart of glomus bodies. A 38-year-old woman was admitted to our clinic presenting morbid obesity. Routine preoperative evaluations, such as laboratory analysis, abdominal ultrasonography, and upper gastrointestinal endoscopy, were performed. She underwent a classical laparoscopic sleeve gastrectomy (LSG). The postoperative course was uneventful and she was discharged for outpatient control. Her histopathology report revealed a GGT 0.8 cm in diameter. No further treatment was done and she had lost 28 kg at the postoperative sixth month. Here, we present the case of GGT, which was diagnosed incidentally after LSG. PMID:27284541

  18. AVO inversion based on inverse operator estimation in trust region

    NASA Astrophysics Data System (ADS)

    Yin, Xing-Yao; Deng, Wei; Zong, Zhao-Yun

    2016-04-01

    Amplitude variation with offset (AVO) inversion is widely utilized in exploration geophysics, especially for reservoir prediction and fluid identification. Inverse operator estimation in the trust region algorithm is applied for solving AVO inversion problems in which optimization and inversion directly are integrated. The L1 norm constraint is considered on the basis of reasonable initial model in order to improve effciency and stability during the AVO inversion process. In this study, high-order Zoeppritz approximation is utilized to establish the inversion objective function in which variation of {{v}\\text{p}}/{{v}\\text{s}} with time is taken into consideration. A model test indicates that the algorithm has a relatively higher stability and accuracy than the damp least-squares algorithm. Seismic data inversion is feasible and inversion values of three parameters ({{v}\\text{p}},{{v}\\text{s}},ρ ) maintain good consistency with logging curves.

  19. Incidental catch of marine birds in high seas driftnets

    USGS Publications Warehouse

    Gould, P.J.; Johnson, D.H.; Shaffer, T.L.; Wohl, K.

    1992-01-01

    The incidental take of marine birds was estimated for the following North Pacific driftnet fisheries in 1990: Japanese squid, Japanese large-mesh, Korean squid, and Taiwanese squid and large-mesh combined. The take was estimated by assuming that the data represented a random sample from an unstratified population of all driftnet fisheries in the North Pacific. Estimates for 13 species or species groups are presented, along with some discussion of inadequacies of the design. About 416,000 marine birds were estimated to be taken incidentally during the 1990 season; 80 % of these were in the Japanese squid fishery. Sooty Shearwaters, Short-tailed Shearwaters, and Laysan Albatrosses were the most common species in the bycatch. Regression models were also developed to explore the relations between bycatch rate of three groups Black-footed Albatross, Laysan Albatross, and dark shearwaters and various explanatory variables, such as latitude, longitude, month, vessel, sea surface temperature, and net soak time (length of time nets were in the water). This was done for only the Japanese squid fishery, for which the most complete information was available. For modelling purposes, fishing operations for each vessel were grouped into 5-degree blocks of latitude and longitude. Results of model building indicated that vessel had a significant influence on bycatch rates of all three groups. This finding emphasizes the importance of the sample of vessels being representative of the entire fleet. In addition, bycatch rates of all three groups varied spatially and temporally. Bycatch rates for Laysan Albatrosses tended to decline during the fishing season, whereas those for Black-footed Albatrosses and dark shearwaters tended to increase as the season progressed. Bycatch rates were positively related to net soak time for Laysan Albatrosses and dark shearwaters. Bycatch rates of dark shearwaters were lower for higher sea surface temperatures.

  20. Inverse heat conduction problems

    NASA Astrophysics Data System (ADS)

    Orlande, Helcio Rangel Barreto

    We present the solution of the following inverse problems: (1) Inverse Problem of Estimating Interface Conductance Between Periodically Contacting Surfaces; (2) Inverse Problem of Estimating Interface Conductance During Solidification via Conjugate Gradient Method; (3) Determination of the Reaction Function in a Reaction-Diffusion Parabolic Problem; and (4) Simultaneous Estimation of Thermal Diffusivity and Relaxation Time with Hyperbolic Heat Conduction Model. Also, we present the solution of a direct problem entitled: Transient Thermal Constriction Resistance in a Finite Heat Flux Tube. The Conjugate Gradient Method with Adjoint Equation was used in chapters 1-3. The more general function estimation approach was treated in these chapters. In chapter 1, we solve the inverse problem of estimating the timewise variation of the interface conductance between periodically contacting solids, under quasi-steady-state conditions. The present method is found to be more accurate than the B-Spline approach for situations involving small periods, which are the most difficult on which to perform the inverse analysis. In chapter 2, we estimate the timewise variation of the interface conductance between casting and mold during the solidification of aluminum. The experimental apparatus used in this study is described. In chapter 3, we present the estimation of the reaction function in a one dimensional parabolic problem. A comparison of the present function estimation approach with the parameter estimation technique, wing B-Splines to approximate the reaction function, revealed that the use of function estimation reduces the computer time requirements. In chapter 4 we present a finite difference solution for the transient constriction resistance in a cylinder of finite length with a circular contact surface. A numerical grid generation scheme was used to concentrate grid points in the regions of high temperature gradients in order to reduce discretization errors. In chapter 6, we

  1. Incidental experiences of regulatory fit and the processing of persuasive appeals.

    PubMed

    Koenig, Anne M; Cesario, Joseph; Molden, Daniel C; Kosloff, Spee; Higgins, E Tory

    2009-10-01

    This article examines how the subjective experiences of "feeling right" from regulatory fit and of "feeling wrong" from regulatory non-fit influence the way people process persuasive messages. Across three studies, incidental experiences of regulatory fit increased reliance on source expertise and decreased resistance to counterpersuasion, whereas incidental experiences of regulatory non-fit increased reliance on argument strength and increased resistance to counterpersuasion. These results suggest that incidental fit and non-fit experiences can produce, respectively, more superficial or more thorough processing of persuasive messages. The mechanisms underlying these effects, and the conditions under which they should and should not be expected, are discussed.

  2. External inverse-Compton Emission from Blazar Jets

    SciTech Connect

    Carson, Jennifer E.; Chiang, James; /SLAC

    2007-09-25

    According to leptonic models for the high-energy emission from blazars, relativistic electrons in the inner jets inverse-Compton scatter photons from a variety of sources. Seed photons are certainly introduced via the synchrotron process from the electrons themselves, but external sources of seed photons may also be present. In this paper, we present detailed derivations of the equations describing external inverse-Compton scattering from two sources of seed photons: direct emission from the accretion disk, and accretion disk photons that have scattered off the broad line region. For each source, we derive the seed photon spectrum incident on the jet, the single electron energy loss rate, and the emitted photon spectrum.

  3. Simulations of Dynamic Relativistic Magnetospheres

    NASA Astrophysics Data System (ADS)

    Parfrey, Kyle Patrick

    Neutron stars and black holes are generally surrounded by magnetospheres of highly conducting plasma in which the magnetic flux density is so high that hydrodynamic forces are irrelevant. In this vanishing-inertia—or ultra-relativistic—limit, magnetohydrodynamics becomes force-free electrodynamics, a system of equations comprising only the magnetic and electric fields, and in which the plasma response is effected by a nonlinear current density term. In this dissertation I describe a new pseudospectral simulation code, designed for studying the dynamic magnetospheres of compact objects. A detailed description of the code and several numerical test problems are given. I first apply the code to the aligned rotator problem, in which a star with a dipole magnetic field is set rotating about its magnetic axis. The solution evolves to a steady state, which is nearly ideal and dissipationless everywhere except in a current sheet, or magnetic field discontinuity, at the equator, into which electromagnetic energy flows and is dissipated. Magnetars are believed to have twisted magnetospheres, due to internal magnetic evolution which deforms the crust, dragging the footpoints of external magnetic field lines. This twisting may be able to explain both magnetars' persistent hard X-ray emission and their energetic bursts and flares. Using the new code, I simulate the evolution of relativistic magnetospheres subjected to slow twisting through large angles. The field lines expand outward, forming a strong current layer; eventually the configuration loses equilibrium and a dynamic rearrangement occurs, involving large-scale rapid magnetic reconnection and dissipation of the free energy of the twisted magnetic field. When the star is rotating, the magnetospheric twisting leads to a large increase in the stellar spin-down rate, which may take place on the long twisting timescale or in brief explosive events, depending on where the twisting is applied and the history of the system

  4. Inverse Functions and their Derivatives.

    ERIC Educational Resources Information Center

    Snapper, Ernst

    1990-01-01

    Presented is a method of interchanging the x-axis and y-axis for viewing the graph of the inverse function. Discussed are the inverse function and the usual proofs that are used for the function. (KR)

  5. Diagnosing particle acceleration in relativistic jets

    NASA Astrophysics Data System (ADS)

    Böttcher, Markus; Baring, Matthew G.; Liang, Edison P.; Summerlin, Errol J.; Fu, Wen; Smith, Ian A.; Roustazadeh, Parisa

    2015-03-01

    The high-energy emission from blazars and other relativistic jet sources indicates that electrons are accelerated to ultra-relativistic (GeV - TeV) energies in these systems. This paper summarizes recent results from numerical studies of two fundamentally different particle acceleration mechanisms potentially at work in relativistic jets: Magnetic-field generation and relativistic particle acceleration in relativistic shear layers, which are likely to be present in relativistic jets, is studied via Particle-in-Cell (PIC) simulations. Diffusive shock acceleration at relativistic shocks is investigated using Monte-Carlo simulations. The resulting magnetic-field configurations and thermal + non-thermal particle distributions are then used to predict multi-wavelength radiative (synchrotron + Compton) signatures of both acceleration scenarios. In particular, we address how anisotropic shear-layer acceleration may be able to circumvent the well-known Lorentz-factor crisis, and how the self-consistent evaluation of thermal + non-thermal particle populations in diffusive shock acceleration simulations provides tests of the bulk Comptonization model for the Big Blue Bump observed in the SEDs of several blazars.

  6. Generalized Ohm's law for relativistic plasmas

    NASA Astrophysics Data System (ADS)

    Kandus, A.; Tsagas, C. G.

    2008-04-01

    We generalize the relativistic expression of Ohm's law by studying a multifluid system of charged species using the 1 + 3 covariant formulation of general relativistic electrodynamics. This is done by providing a fully relativistic, fully non-linear propagation equation for the spatial component of the electric 4-current. Our analysis proceeds along the lines of the non-relativistic studies and extends previous relativistic work on cold plasmas. Exploiting the compactness and transparency of the covariant formalism, we provide a direct comparison with the standard Newtonian versions of Ohm's law and identify the relativistic corrections in an unambiguous way. The generalized expression of Ohm's law is initially given relative to an arbitrary observer and for a multicomponent relativistic charged medium. Then, the law is written with respect to the Eckart frame and for a hot two-fluid plasma with zero total charge. Finally, we apply our analysis to a cold proton-electron plasma and recover the well-known magnetohydrodynamic expressions. In every step, we discuss the approximations made and identify familiar effects, like the Biermann battery and the Hall effect.

  7. Relativistic effects in Lyman-α forest

    NASA Astrophysics Data System (ADS)

    Iršič, Vid; Di Dio, Enea; Viel, Matteo

    2016-02-01

    We present the calculation of the Lyman-alpha (Lyman-α) transmitted flux fluctuations with full relativistic corrections to the first order. Even though several studies exist on relativistic effects in galaxy clustering, this is the first study to extend the formalism to a different tracer of underlying matter at unique redshift range (z=2-5). Furthermore, we show a comprehensive application of our calculations to the Quasar-Lyman-α cross-correlation function. Our results indicate that the signal of relativistic effects are sizeable at Baryonic Acoustic Oscillation (BAO) scale mainly due to the large differences in density bias factors of our tracers. We construct an observable, the anti-symmetric part of the cross-correlation function, that is dominated by the relativistic signal and offers a new way to measure the relativistic terms at relatively small scales. The analysis shows that relativistic effects are important when considering cross-correlations between tracers with very different biases, and should be included in the data analysis of the current and future surveys. Moreover, the idea presented in this paper is highly complementary to other techniques and observables trying to isolate the effect of the relativistic corrections and thus test the validity of the theory of gravity beyond the Newtonian regime.

  8. Intersections, ideals, and inversion

    SciTech Connect

    Vasco, D.W.

    1998-10-01

    Techniques from computational algebra provide a framework for treating large classes of inverse problems. In particular, the discretization of many types of integral equations and of partial differential equations with undetermined coefficients lead to systems of polynomial equations. The structure of the solution set of such equations may be examined using algebraic techniques.. For example, the existence and dimensionality of the solution set may be determined. Furthermore, it is possible to bound the total number of solutions. The approach is illustrated by a numerical application to the inverse problem associated with the Helmholtz equation. The algebraic methods are used in the inversion of a set of transverse electric (TE) mode magnetotelluric data from Antarctica. The existence of solutions is demonstrated and the number of solutions is found to be finite, bounded from above at 50. The best fitting structure is dominantly onedimensional with a low crustal resistivity of about 2 ohm-m. Such a low value is compatible with studies suggesting lower surface wave velocities than found in typical stable cratons.

  9. Playing relativistic billiards beyond graphene

    NASA Astrophysics Data System (ADS)

    Sadurní, E.; Seligman, T. H.; Mortessagne, F.

    2010-05-01

    The possibility of using hexagonal structures in general, and graphene in particular, to emulate the Dirac equation is the topic under consideration here. We show that Dirac oscillators with or without rest mass can be emulated by distorting a tight-binding model on a hexagonal structure. In the quest to make a toy model for such relativistic equations, we first show that a hexagonal lattice of attractive potential wells would be a good candidate. Firstly, we consider the corresponding one-dimensional (1D) model giving rise to a 1D Dirac oscillator and then construct explicitly the deformations needed in the 2D case. Finally, we discuss how such a model can be implemented as an electromagnetic billiard using arrays of dielectric resonators between two conducting plates that ensure evanescent modes outside the resonators for transversal electric modes, and we describe a feasible experimental setup.

  10. Invisibility cloaks in relativistic motion

    NASA Astrophysics Data System (ADS)

    Halimeh, Jad C.; Thompson, Robert T.; Wegener, Martin

    2016-01-01

    We consider an ideal invisibility cloak which is illuminated by monochromatic light and which moves in vacuum at constant relativistic velocity with respect to the common inertial frame of light source and observer. We show that, in general, the moving cloak becomes detectable by image distortions and by generating a broad frequency spectrum of the scattered light. However, for many special combinations of incident light frequency, wave vector of light, and cloak velocity, ideal cloaking remains possible. It becomes nonreciprocal though. This means that light rays emitted by the light source arrive at the observer as though they have traveled through vacuum, but they take completely different paths after being retroreflected at the observer position.

  11. Landau damping in relativistic plasmas

    NASA Astrophysics Data System (ADS)

    Young, Brent

    2016-02-01

    We examine the phenomenon of Landau damping in relativistic plasmas via a study of the relativistic Vlasov-Poisson (rVP) system on the torus for initial data sufficiently close to a spatially uniform steady state. We find that if the steady state is regular enough (essentially in a Gevrey class of degree in a specified range) and if the deviation of the initial data from this steady state is small enough in a certain norm, the evolution of the system is such that its spatial density approaches a uniform constant value quasi-exponentially fast (i.e., like exp ( - C |" separators=" t | ν ¯ ) for ν ¯ ∈ ( 0 , 1 ) ). We take as a priori assumptions that solutions launched by such initial data exist for all times (by no means guaranteed with rVP, but a reasonable assumption since we are close to a spatially uniform state) and that the various norms in question are continuous in time (which should be a consequence of an abstract version of the Cauchy-Kovalevskaya theorem). In addition, we must assume a kind of "reverse Poincaré inequality" on the Fourier transform of the solution. In spirit, this assumption amounts to the requirement that there exists 0 < ϰ < 1 so that the mass in the annulus ϰ ≤ |" separators=" v | < 1 for the solution launched by the initial data is uniformly small for all t. Typical velocity bounds for solutions to rVP launched by small initial data (at least on ℝ6) imply this bound. We note that none of our results require spherical symmetry (a crucial assumption for many current results on rVP).

  12. Relativistic Theory of Few Body Systems

    SciTech Connect

    Franz Gross

    2002-11-01

    Very significant advances have been made in the relativistic theory of few body systems since I visited Peter Sauer and his group in Hannover in 1983. This talk provides an opportunity to review the progress in this field since then. Different methods for the relativistic calculation of few nucleon systems are briefly described. As an example, seven relativistic calculations of the deuteron elastic structure functions, A, B, and T{sub 20}, are compared. The covariant SPECTATOR {copyright} theory, among the more successful and complete of these methods, is described in more detail.

  13. STREAM INSTABILITIES IN RELATIVISTICALLY HOT PLASMA

    SciTech Connect

    Shaisultanov, Rashid; Lyubarsky, Yuri; Eichler, David

    2012-01-10

    The growth rates for Weibel and Buneman instabilities of relativistic ion beams in a relativistically hot electron background are derived analytically for general propagation angles. The Weibel instability perpendicular to the streaming direction is found to be the fastest growing mode and probably the first to appear. Oblique, quasiperpendicular modes grow almost as fast as the growth rate varies only moderately with angle, and they may distort or corrugate the filaments after the perpendicular mode saturates. The growth rate of the purely longitudinal (Buneman) mode is significantly smaller, contrary to the non-relativistic case. The results are consistent with simulations, which display aligned magnetic filaments and their subsequent disruption.

  14. Relativistic klystron research for linear colliders

    SciTech Connect

    Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Herrmannsfeldt, W.B.; Higo, T.; Hoag, H.A.; Koontz, R.F.

    1988-09-01

    Relativistic klystrons are being developed as a power source for high gradient accelerator applications which include large linear electron-positron colliders, compact accelerators, and FEL sources. We have attained 200 MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. We report here on the design of our relativistic klystrons, the results of our experiments so far, and some of our plans for the near future. 5 refs., 9 figs., 1 tab.

  15. Relativistic quantum mechanics and relativistic entanglement in the rest-frame instant form of dynamics

    SciTech Connect

    Alba, David; Crater, Horace W.; Lusanna, Luca

    2011-06-15

    A new formulation of relativistic quantum mechanics is proposed in the framework of the rest-frame instant form of dynamics, where the world-lines of the particles are parametrized in terms of the Fokker-Pryce center of inertia and of Wigner-covariant relative 3-coordinates inside the instantaneous Wigner 3-spaces, and where there is a decoupled (non-covariant and non-local) canonical relativistic center of mass. This approach: (a) allows us to make a consistent quantization in every inertial frame; (b) leads to a description of both bound and scattering states; (c) offers new insights on the relativistic localization problem; (d) leads to a non-relativistic limit with a Hamilton-Jacobi treatment of the Newton center of mass; (e) clarifies non-local aspects (spatial non-separability) of relativistic entanglement connected with Lorentz signature and not present in its non-relativistic treatment.

  16. Do researchers have an obligation to actively look for genetic incidental findings?

    PubMed

    Gliwa, Catherine; Berkman, Benjamin E

    2013-01-01

    The rapid growth of next-generation genetic sequencing has prompted debate about the responsibilities of researchers toward genetic incidental findings. Assuming there is a duty to disclose significant incidental findings, might there be an obligation for researchers to actively look for these findings? We present an ethical framework for analyzing whether there is a positive duty to look for genetic incidental findings. Using the ancillary care framework as a guide, we identify three main criteria that must be present to give rise to an obligation to look: high benefit to participants, lack of alternative access for participants, and reasonable burden on researchers. Our analysis indicates that there is no obligation to look for incidental findings today, but during the ongoing translation of genomic analysis from research to clinical care, this obligation may arise.

  17. 78 FR 61379 - Proposed Information Collection; Incidental Take of Marine Mammals During Specified Oil and Gas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... their incidental taking of polar bears and Pacific walruses in the Beaufort and Chukchi Seas. The Marine... and Pacific walruses and the availability of those marine mammals for subsistence purposes of...

  18. 50 CFR 216.161 - Specified activity and incidental take levels by species.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Taking of Marine Mammals Incidental to Shock Testing... one full ship-shock trial (FSST) of the USS MESA VERDE (LPD 19) during the time period between July...

  19. Do Researchers Have an Obligation to Actively Look for Genetic Incidental Findings?

    PubMed Central

    Gliwa, Catherine; Berkman, Benjamin E.

    2014-01-01

    The rapid growth of next-generation genetic sequencing has prompted debate about the responsibilities of researchers toward genetic incidental findings. Assuming there is a duty to disclose significant incidental findings, might there be an obligation for researchers to actively look for these findings? We present an ethical framework for analyzing whether there is a positive duty to look for genetic incidental findings. Using the ancillary care framework as a guide, we identify three main criteria that must be present to give rise to an obligation to look: high benefit to participants, lack of alternative access for participants, and reasonable burden on researchers. Our analysis indicates that there is no obligation to look for incidental findings today, but during the ongoing translation of genomic analysis from research to clinical care, this obligation may arise. PMID:23391059

  20. Incidental acquisition of foreign language vocabulary through brief multi-modal exposure.

    PubMed

    Bisson, Marie-Josée; van Heuven, Walter J B; Conklin, Kathy; Tunney, Richard J

    2013-01-01

    First language acquisition requires relatively little effort compared to foreign language acquisition and happens more naturally through informal learning. Informal exposure can also benefit foreign language learning, although evidence for this has been limited to speech perception and production. An important question is whether informal exposure to spoken foreign language also leads to vocabulary learning through the creation of form-meaning links. Here we tested the impact of exposure to foreign language words presented with pictures in an incidental learning phase on subsequent explicit foreign language learning. In the explicit learning phase, we asked adults to learn translation equivalents of foreign language words, some of which had appeared in the incidental learning phase. Results revealed rapid learning of the foreign language words in the incidental learning phase showing that informal exposure to multi-modal foreign language leads to foreign language vocabulary acquisition. The creation of form-meaning links during the incidental learning phase is discussed.

  1. BOOK REVIEW: Relativistic Figures of Equilibrium

    NASA Astrophysics Data System (ADS)

    Mars, M.

    2009-08-01

    losing material, and the black hole transition, where rotating fluids are seen to approach black holes for suitable limits of their parameters. As the authors themselves mention, one of the emphasis of this book is placed 'on the rigorous treatment of simple models instead of trying to describe real objects with their many complex facets...'. After discussing constant density models both in Newtonian theory (the Maclaurin spheroids) and in the non-rotating relativistic case (the Schwarzschild interior model), the book concentrates on the so-called rigidly rotating disc of dust. Chapter two is mainly devoted to deriving this model and presenting its physical properties. The derivation is based in the so-called inverse scattering method of integrable systems and on a thorough knowledge of the theory of integration on Riemann surfaces. The details, which take up about one fifth of the whole length, are difficult to follow for any reader without a previous mastering of the techniques involved. For the expert, however, this part of the book is very useful because it brings together all the steps required for the complete determination of the solution. After the derivation of the disc of dust, the physical properties of the resulting one-parameter family of solutions are described, including its multipole moment structure, the existence of ergospheres, the Newtonian limit or the motion of test particles. Of particular interest is the transition from the disc of dust to the extreme black hole configuration corresponding to the limit when the parameter describing the fluid approaches its upper end. After this chapter devoted to exact models, the book looks at the problem from a completely different point of view, namely by using numerical methods. This tool has proven to be fundamental for a proper study of this physical problem. This book concentrates on the so-called pseudo-spectral methods and the use of multidomains adapted to the different regions of the spacetime with

  2. Relative Preference and Localized Food Affect Predator Space Use and Consumption of Incidental Prey.

    PubMed

    Schartel, Tyler E; Schauber, Eric M

    2016-01-01

    Abundant, localized foods can concentrate predators and their foraging efforts, thus altering both the spatial distribution of predation risk and predator preferences for prey that are encountered incidentally. However, few investigations have quantified the spatial scale over which localized foods affect predator foraging behavior and consumption of incidental prey. In spring 2010, we experimentally tested how point-source foods altered how generalist predators (white-footed mice, Peromyscus leucopus) utilized space and depredated two incidental prey items: almonds (Prunus dulcis; highly profitable) and maple seeds (Acer saccharum; less profitable). We estimated mouse population densities with trapping webs, quantified mouse consumption rates of these incidental prey items, and measured local mouse activity with track plates. We predicted that 1) mouse activity would be elevated near full feeders, but depressed at intermediate distances from the feeder, 2) consumption of both incidental prey would be high near feeders providing less-preferred food and, 3) consumption of incidental prey would be contingent on predator preference for prey relative to feeders providing more-preferred food. Mouse densities increased significantly from pre- to post-experiment. Mean mouse activity was unexpectedly greatest in control treatments, particularly <15 m from the control (empty) feeder. Feeders with highly preferred food (sunflower seeds) created localized refuges for incidental prey at intermediate distances (15 to 25m) from the feeder. Feeders with less-preferred food (corn) generated localized high risk for highly preferred almonds <10 m of the feeder. Our findings highlight the contingent but predictable effects of locally abundant food on risk experienced by incidental prey, which can be positive or negative depending on both spatial proximity and relative preference.

  3. Relative Preference and Localized Food Affect Predator Space Use and Consumption of Incidental Prey.

    PubMed

    Schartel, Tyler E; Schauber, Eric M

    2016-01-01

    Abundant, localized foods can concentrate predators and their foraging efforts, thus altering both the spatial distribution of predation risk and predator preferences for prey that are encountered incidentally. However, few investigations have quantified the spatial scale over which localized foods affect predator foraging behavior and consumption of incidental prey. In spring 2010, we experimentally tested how point-source foods altered how generalist predators (white-footed mice, Peromyscus leucopus) utilized space and depredated two incidental prey items: almonds (Prunus dulcis; highly profitable) and maple seeds (Acer saccharum; less profitable). We estimated mouse population densities with trapping webs, quantified mouse consumption rates of these incidental prey items, and measured local mouse activity with track plates. We predicted that 1) mouse activity would be elevated near full feeders, but depressed at intermediate distances from the feeder, 2) consumption of both incidental prey would be high near feeders providing less-preferred food and, 3) consumption of incidental prey would be contingent on predator preference for prey relative to feeders providing more-preferred food. Mouse densities increased significantly from pre- to post-experiment. Mean mouse activity was unexpectedly greatest in control treatments, particularly <15 m from the control (empty) feeder. Feeders with highly preferred food (sunflower seeds) created localized refuges for incidental prey at intermediate distances (15 to 25m) from the feeder. Feeders with less-preferred food (corn) generated localized high risk for highly preferred almonds <10 m of the feeder. Our findings highlight the contingent but predictable effects of locally abundant food on risk experienced by incidental prey, which can be positive or negative depending on both spatial proximity and relative preference. PMID:26978659

  4. Incidentally Detected Mediastinal Vascular Anatomical Variants on PET-CT: A Pictorial Essay.

    PubMed

    Paidipati, Kathyayini Gopalkrishna Murthy; Kashyap, Raghava; Tadimeti, Hima; Peyyeti, Mahidhar

    2015-01-01

    Positron emission tomography with computed tomography (PET-CT) is an integral part of oncology practice in the current-day scenario. The hybrid anatomical and metabolic imaging information in this imaging modality provides access to a wealth of incidental findings which can have implications in the management of the patient, especially when surgical options are being considered. In this pictorial essay, we present incidentally detected mediastinal vascular anomalies on PET-CT, along with a review of associated literature.

  5. Identification of Incidental Pulmonary Nodules in Free-text Radiology Reports: An Initial Investigation.

    PubMed

    Oliveira, Lucas; Tellis, Ranjith; Qian, Yuechen; Trovato, Karen; Mankovich, Gabe

    2015-01-01

    Advances in image quality produced by computed tomography (CT) and the growth in the number of image studies currently performed has made the management of incidental pulmonary nodules (IPNs) a challenging task. This research aims to identify IPNs in radiology reports of chest and abdominal CT by Natural Language Processing techiniques to recognize IPN in sentences of radiology reports. Our preliminary analysis indicates vastly different pulmonary incidental findings rates for two different patient groups. PMID:26262327

  6. Incidentally Detected Mediastinal Vascular Anatomical Variants on PET-CT: A Pictorial Essay

    PubMed Central

    Paidipati, Kathyayini Gopalkrishna Murthy; Kashyap, Raghava; Tadimeti, Hima; Peyyeti, Mahidhar

    2015-01-01

    Positron emission tomography with computed tomography (PET–CT) is an integral part of oncology practice in the current-day scenario. The hybrid anatomical and metabolic imaging information in this imaging modality provides access to a wealth of incidental findings which can have implications in the management of the patient, especially when surgical options are being considered. In this pictorial essay, we present incidentally detected mediastinal vascular anomalies on PET–CT, along with a review of associated literature. PMID:25883859

  7. Relative Preference and Localized Food Affect Predator Space Use and Consumption of Incidental Prey

    PubMed Central

    Schartel, Tyler E.; Schauber, Eric M.

    2016-01-01

    Abundant, localized foods can concentrate predators and their foraging efforts, thus altering both the spatial distribution of predation risk and predator preferences for prey that are encountered incidentally. However, few investigations have quantified the spatial scale over which localized foods affect predator foraging behavior and consumption of incidental prey. In spring 2010, we experimentally tested how point-source foods altered how generalist predators (white-footed mice, Peromyscus leucopus) utilized space and depredated two incidental prey items: almonds (Prunus dulcis; highly profitable) and maple seeds (Acer saccharum; less profitable). We estimated mouse population densities with trapping webs, quantified mouse consumption rates of these incidental prey items, and measured local mouse activity with track plates. We predicted that 1) mouse activity would be elevated near full feeders, but depressed at intermediate distances from the feeder, 2) consumption of both incidental prey would be high near feeders providing less-preferred food and, 3) consumption of incidental prey would be contingent on predator preference for prey relative to feeders providing more-preferred food. Mouse densities increased significantly from pre- to post-experiment. Mean mouse activity was unexpectedly greatest in control treatments, particularly <15 m from the control (empty) feeder. Feeders with highly preferred food (sunflower seeds) created localized refuges for incidental prey at intermediate distances (15 to 25m) from the feeder. Feeders with less-preferred food (corn) generated localized high risk for highly preferred almonds <10 m of the feeder. Our findings highlight the contingent but predictable effects of locally abundant food on risk experienced by incidental prey, which can be positive or negative depending on both spatial proximity and relative preference. PMID:26978659

  8. Ultraviolet Lasing in Air Caused by Intense Relativistic Electron Beams.

    NASA Astrophysics Data System (ADS)

    Atchison, Walter Louis

    As an intense relativistic electron beam (REB) passes through the atmosphere, it interacts heavily with the N_2 present and produces a large population of excited molecules. Calculations presented indicate that the excitation rates and the Franck-Condon factors combine to cause a population inversion for selected states in the triplet manifold of N_2. This inversion and the geometry of the propagating beam causes amplified spontaneous emission which is greatest in the axially direction of REB propagation. The ultraviolet (UV) yields from the N_2 triplet states caused by a REB have been calculated for the pressure range 0.5 to 1000 torr. As the REB and UV pulse propagate together at or near the speed of light, an interesting condition results. Normal geometric and temporal considerations which affect typical discharge lasers do not, in this case, limit the pulse width and total amplitude of the UV pulse. Calculations predict significant yields at pressures above 100 torr. The yield in this region is aided by the electron cascade caused by the primary electrons of the REB. Measurements along the propagation axis using the LLNL Experimental Test Accelerator (ETA), while insufficient to verify the pressure dependence, indicate enhancement of 3371 A emissions by at least a factor of 1000 over the level predicted by spontaneous emission alone.

  9. Theory of symmetry for a rotational relativistic Birkhoff system

    NASA Astrophysics Data System (ADS)

    Luo, Shao-Kai; Chen, Xiang-Wei; Guo, Yong-Xin

    2002-05-01

    The theory of symmetry for a rotational relativistic Birkhoff system is studied. In terms of the invariance of the rotational relativistic Pfaff-Birkhoff-D'Alembert principle under infinitesimal transformations, the Noether symmetries and conserved quantities of a rotational relativistic Birkhoff system are given. In terms of the invariance of rotational relativistic Birkhoff equations under infinitesimal transformations, the Lie symmetries and conserved quantities of the rotational relativistic Birkhoff system are given.

  10. Relativistic radiative transfer in relativistic plane-parallel flows: Behavior of the Eddington factor

    NASA Astrophysics Data System (ADS)

    Fukue, Jun

    2014-07-01

    Relativistic radiative transfer in a relativistic plane-parallel flow which is accelerated from its base, like an accretion disk wind, is numerically examined under a fully special-relativistic treatment. We first derive relativistic formal solutions. We then iteratively solve the relativistic transfer equation for several cases such as radiative equilibrium or local thermodynamic equilibrium, and obtain specific intensities in the inertial and comoving frames, as well as moment quantities and the Eddington factor. Moment quantities are rather different in each case, but the behavior of the Eddington factor for the plane-parallel case is quite similar in all cases. The Eddington factor generally depends on the flow velocity v as well as the optical depth τ. In the case of relativistic plane-parallel flows, in an optically thin regime of τ ≲ 1, it is slightly larger than 1/3 at very slow speed, it becomes smaller than 1/3 at mildly relativistic speed, and it again increases up to unity in the highly relativistic case. At highly relativistic speed, on the other hand, it becomes larger than 1/3 even in an optically thick regime. We find the Eddington approximation is fairly good, except for τ ≲ 1 or v/c ≳ 0.9, although the moment formalism under the Eddington approximation has some defects at v/c=1/√{3}.

  11. Incidental Findings on Cone Beam Computed Tomography Studies outside of the Maxillofacial Skeleton

    PubMed Central

    2016-01-01

    Objective. To define the presence and prevalence of incidental findings in and around the base of skull from large field-of-view CBCT of the maxillofacial region and to determine their clinical importance. Methods. Four hundred consecutive large fields of view CBCT scans viewed from January 1, 2007, to January 1, 2014, were retrospectively evaluated for incidental findings of the cervical vertebrae and surrounding structures. Findings were categorized into cervical vertebrae, intracranial, soft tissue, airway, carotid artery, lymph node, and skull base findings. Results. A total of 653 incidental findings were identified in 309 of the 400 CBCT scans. The most prevalent incidental findings were soft tissue calcifications (29.71%), followed by intracranial calcifications (27.11%), cervical vertebrae (20.06%), airway (11.49%), external carotid artery calcification (10.41%), lymph node calcification (0.77%), subcutaneous tissue calcification and calcified tendonitis of the longus colli muscle (0.3%), and skull base finding (0.15%). A significant portion of the incidental findings (31.24%) required referral, 17.76% required monitoring, and 51% did not require either. Conclusion. A comprehensive review of the CBCT images beyond the region of interest, especially incidental findings in the base of skull, cervical vertebrae, pharyngeal airway, and soft tissue, is necessary to avoid overlooking clinically significant lesions. PMID:27462350

  12. The role of verbal and pictorial information in multimodal incidental acquisition of foreign language vocabulary.

    PubMed

    Bisson, Marie-Josée; van Heuven, Walter J B; Conklin, Kathy; Tunney, Richard J

    2015-01-01

    This study used eye tracking to investigate the allocation of attention to multimodal stimuli during an incidental learning situation, as well as its impact on subsequent explicit learning. Participants were exposed to foreign language (FL) auditory words on their own, in conjunction with written native language (NL) translations, or with both written NL translations and pictures. Incidental acquisition of FL words was assessed the following day through an explicit learning task where participants learned to recognize translation equivalents, as well as one week later through recall and translation recognition tests. Results showed higher accuracy scores in the explicit learning task for FL words presented with meaning during incidental learning, whether written meaning or both written meaning and picture, than for FL words presented auditorily only. However, participants recalled significantly more FL words after a week delay if they had been presented with a picture during incidental learning. In addition, the time spent looking at the pictures during incidental learning significantly predicted recognition and recall scores one week later. Overall, results demonstrated the impact of exposure to multimodal stimuli on subsequent explicit learning, as well as the important role that pictorial information can play in incidental vocabulary acquisition.

  13. ULTRA-RELATIVISTIC NUCLEI: A NEW FRONTIER

    SciTech Connect

    MCLERRAN,L.

    1999-10-29

    The collisions of ultra-relativistic nuclei provide a window on the behavior of strong interactions at asymptotically high energies. They also will allow the authors to study the bulk properties of hadronic matter at very high densities.

  14. Relativistic perturbations for all the planets

    NASA Astrophysics Data System (ADS)

    Lestrade, J.-F.; Bretagnon, P.

    1982-01-01

    The relativistic perturbations in the osculating elements of all the planets, due to the theory of General Relativity, are presented where only the gravitational field of the sun is taken into account and the effects are calculated in the post-Newtonian approximation. The relativistic effects are calculated with the requirement that an accuracy of 5 x 10 to the -12th UA be kept over an interval of 1000 years, and are expressed in series form depending on the dynamical time in the isotropic coordinate and standard coordinate systems. The method uses equations derived from the equations of Gauss for the relativistic acceleration. A theory of the motion of Mercury is derived through the addition of the relativistic perturbations to the third-order Newtonian theory of Bretagnon (1981). It is noted that the computer programs used allow any values for the physical parameters Gamma and Beta of the Eddigton-Robertson metric.

  15. Relativistic Thomson Scatter from Factor Calculation

    2009-11-01

    The purpose of this program is calculate the fully relativistic Thomson scatter from factor in unmagnetized plasmas. Such calculations are compared to experimental diagnoses of plasmas at such facilities as the Jupiter laser facility here a LLNL.

  16. Pseudospectral approach to relativistic molecular theory.

    PubMed

    Nakajima, Takahito; Hirao, Kimihiko

    2004-08-22

    The efficient relativistic Dirac-Hartree-Fock (DHF) and Dirac-Kohn-Sham (DKS) methods are proposed by an application of the pseudospectral (PS) approach. The present PS-DHF/DKS method is a relativistic extension of the PS-HF/KS method of Friesner, though we aim at higher numerical accuracy by elimination of superfluous arbitrariness. The relativistic PS-DHF/DKS method is implemented into our REL4D programs. Several PS applications to molecular systems show that the relativistic PS-DHF/DKS approach is more efficient than the traditional approach without a loss of accuracy. The present PS-DKS method successfully assigns and predicts the photoelectron spectra of hexacarbonyl complexes of tungsten and seaborgium theoretically.

  17. Classical dynamics of the relativistic oscillator

    NASA Astrophysics Data System (ADS)

    Petrov, S. V.

    2016-11-01

    This paper aims at a comprehensive analysis of the dynamics of the classical relativistic oscillator. Numerical integration of its dynamical equations permits a thorough treatment of its motion. Both the one-dimensional and two-dimensional cases are considered.

  18. Relativistic quark-diquark model of baryons

    SciTech Connect

    Ferretti, J.; Vassallo, A.; Santopinto, E.

    2011-06-15

    A relativistic quark-diquark mass operator with direct and exchange interaction has been constructed in the framework of point form dynamics. The nonstrange baryon spectrum has been calculated and compared with experimental data.

  19. Quantum probability assignment limited by relativistic causality

    PubMed Central

    Han, Yeong Deok; Choi, Taeseung

    2016-01-01

    Quantum theory has nonlocal correlations, which bothered Einstein, but found to satisfy relativistic causality. Correlation for a shared quantum state manifests itself, in the standard quantum framework, by joint probability distributions that can be obtained by applying state reduction and probability assignment that is called Born rule. Quantum correlations, which show nonlocality when the shared state has an entanglement, can be changed if we apply different probability assignment rule. As a result, the amount of nonlocality in quantum correlation will be changed. The issue is whether the change of the rule of quantum probability assignment breaks relativistic causality. We have shown that Born rule on quantum measurement is derived by requiring relativistic causality condition. This shows how the relativistic causality limits the upper bound of quantum nonlocality through quantum probability assignment. PMID:26971717

  20. Quantum Deformations of Einstein's Relativistic Symmetries

    SciTech Connect

    Lukierski, Jerzy

    2006-11-03

    We shall outline two ways of introducing the modification of Einstein's relativistic symmetries of special relativity theory -- the Poincare symmetries. The most complete way of introducing the modifications is via the noncocommutative Hopf-algebraic structure describing quantum symmetries. Two types of quantum relativistic symmetries are described, one with constant commutator of quantum Minkowski space coordinates ({theta}{mu}{nu}-deformation) and second with Lie-algebraic structure of quantum space-time, introducing so-called {kappa}-deformation. The third fundamental constant of Nature - fundamental mass {kappa} or length {lambda} - appears naturally in proposed quantum relativistic symmetry scheme. The deformed Minkowski space is described as the representation space (Hopf-module) of deformed Poincare algebra. Some possible perspectives of quantum-deformed relativistic symmetries will be outlined.

  1. Relativistic projection and boost of solitons

    SciTech Connect

    Wilets, L.

    1991-01-01

    This report discusses the following topics on the relativistic projection and boost of solitons: The center of mass problem; momentum eigenstates; variation after projection; and the nucleon as a composite. (LSP).

  2. Relativistic projection and boost of solitons

    SciTech Connect

    Wilets, L.

    1991-12-31

    This report discusses the following topics on the relativistic projection and boost of solitons: The center of mass problem; momentum eigenstates; variation after projection; and the nucleon as a composite. (LSP).

  3. Coherent states for the relativistic harmonic oscillator

    NASA Technical Reports Server (NTRS)

    Aldaya, Victor; Guerrero, J.

    1995-01-01

    Recently we have obtained, on the basis of a group approach to quantization, a Bargmann-Fock-like realization of the Relativistic Harmonic Oscillator as well as a generalized Bargmann transform relating fock wave functions and a set of relativistic Hermite polynomials. Nevertheless, the relativistic creation and annihilation operators satisfy typical relativistic commutation relations of the Lie product (vector-z, vector-z(sup dagger)) approximately equals Energy (an SL(2,R) algebra). Here we find higher-order polarization operators on the SL(2,R) group, providing canonical creation and annihilation operators satisfying the Lie product (vector-a, vector-a(sup dagger)) = identity vector 1, the eigenstates of which are 'true' coherent states.

  4. Incidental gallbladder cancer after cholecystectomy: 1990 to 2014

    PubMed Central

    Dorobisz, Tadeusz; Dorobisz, Karolina; Chabowski, Mariusz; Pawłowski, Wiktor; Janczak, Dawid; Patrzałek, Dariusz; Janczak, Dariusz

    2016-01-01

    Introduction Cancer of the gallbladder is a serious diagnostic and therapeutic problem. According to the literature, 30% of cases are not confirmed before surgery. Other cases are detected incidentally by histopathology. Clinical trials and meta-analyses show that incidental gallbladder cancer (iGBC) occurs in 0.19%–2.8% of patients after cholecystectomy. The aim of this study was to analyze the incidence and severity of iGBC in cholecystectomy procedures performed in the surgical department at the 4th Military Teaching Hospital in Wroclaw during the years 1990–2014. Patients and methods In the years 1990–2014, a total of 7,314 cholecystectomies were performed in the surgical department because of cholecystolithiasis: 6,145 were performed using the laparoscopic approach (84.02%), 867 were performed as open surgery (11.8%), and 302 cases required conversion (5.1%). In this group, 5,214 of the patients were females (71.3%) and 2,100 were males (28.7%), with an average age of 54.7 years. Results We found 64 iGBC cases which were confirmed by histopathology. This represented 0.87% of all cases. In this group, 50 patients were females (78.1%) and 14 were males (21.8%), with an average age of 67.1 years. Of this group, 40 patients underwent a classic cholecystectomy, while 24 underwent laparoscopic procedures, out of which 13 cases ultimately required traditional surgery. The histopathology showed 15 carcinomas that were classified as G1 (23.4%), 28 were G2 (43.75%), and 21 were G3 (32.8%). Conclusion iGBC detected after a cholecystectomy due to cholecystolithiasis is a rare disease. We found iGBC in 0.87% of cases, which is on a comparable scale to the world literature. In the case of cancer, we frequently found it necessary to convert to an open surgical procedure. This cancer is more common in females and in people over 60 years of age. PMID:27540304

  5. Relativistic particle beams for interstellar propulsion

    NASA Astrophysics Data System (ADS)

    Nordley, Gerald D.

    1993-04-01

    The concept of pellet-stream propulsion proposed by Singer (1980) is extended to particle beams and relativistic velocities. A simple relativistic mission study is presented, and it is shown how certain technological developments might enhance the concept. In particular, considerations discussed include beam drivers; beam cooling, steering, and focusing; beam driven mission mechanics; and the radiation problem. The energy issues are also briefly considered.

  6. Mass versus relativistic and rest masses

    NASA Astrophysics Data System (ADS)

    Okun, L. B.

    2009-05-01

    The concept of relativistic mass, which increases with velocity, is not compatible with the standard language of relativity theory and impedes the understanding and learning of the theory by beginners. The same difficulty occurs with the term rest mass. To get rid of relativistic mass and rest mass it is appropriate to replace the equation E =mc2 by the true Einstein's equation E0=mc2, where E0 is the rest energy and m is the mass.

  7. On Lorentz invariants in relativistic magnetic reconnection

    NASA Astrophysics Data System (ADS)

    Yang, Shu-Di; Wang, Xiao-Gang

    2016-08-01

    Lorentz invariants whose nonrelativistic correspondences play important roles in magnetic reconnection are discussed in this paper. Particularly, the relativistic invariant of the magnetic reconnection rate is defined and investigated in a covariant two-fluid model. Certain Lorentz covariant representations for energy conversion and magnetic structures in reconnection processes are also investigated. Furthermore, relativistic measures for topological features of reconnection sites, particularly magnetic nulls and separatrices, are analyzed.

  8. Relativistic mean field description of exotic nuclei

    NASA Astrophysics Data System (ADS)

    Meng, Jie; Ring, Peter; Zhao, Pengwei; Zhou, Shan-Gui

    In this chapter, we will present relativistic mean field (RMF) models with pairing treated by the Bardeen-Cooper-Schrieffer (BCS) and the relativistic Hartree-Bogoliubov (RHB) approaches and applications for exotic nuclear phenomena including nuclear halos, the position of the proton drip line and proton radioactivity, the surface diffuseness and its relation to nuclear exotic phenomena, and the effects of pairing correlations on the nuclear size.

  9. Relativistic uranium beams - the Bevalac experience

    SciTech Connect

    Alonso, J.

    1983-03-01

    This paper will address areas where relativistic heavy ion accelerators differ from proton facilities. Salient areas are: (1) the specialized injectors for heavy ions; ion sources, structures for very low charge-to-mass ratio (q/A) ions, and stripper optimization; (2) special requirements for the synchrotron ring; ultrahigh vacuum, flexible controls and instrumentation. These areas are discussed in the context of the Bevalac, as well as our idea for a next-generation relativistic heavy ion accelerator.

  10. Relativistic klystron research at SLAC and LLNL

    SciTech Connect

    Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fowkes, W.R.; Herrmannsfeldt, W.B.; Higo, T.; Hoag, H.A.; Lavine, T.L.; Lee, T.G.; Loew, G.A.; Miller, R.H.; Morton, P.L.; Palmer, R.B.; Paterson, J.M.; Ruth, R.D.; Schwarz, H.D.; Takeuchi, Y.; Vlieks, A.E.; Wang, J.W.; Wilson, P.B.; Hopkins, D.B.; Sessler, A.M.; Barletta, W.A.; Birx, D.L.; Boyd, J.K.; Houck, T.; Westenskow, G.A.; Yu, S.S.

    1988-06-01

    We are developing relativistic klystrons as a power source for high gradient accelerator applications such as large linear electron-positron colliders and compact accelerators. We have attained 200 MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. We report here briefly on our experiments so far. 5 refs., 1 fig., 1 tab.

  11. Relativistically modulational instability by strong Langmuir waves

    SciTech Connect

    Liu, X. L.; Liu, S. Q.; Li, X. Q.

    2012-09-15

    Based on the set of nonlinear coupling equations, which has considered the relativistic effects of electrons, modulational instability by strong Langmuir waves has been investigated in this paper. Both the characteristic scale and maximum growth rate of the Langmuir field will enhance with the increase in the electron relativistic effect. The numerical results indicate that longitudinal perturbations induce greater instability than transverse perturbations do, which will lead to collapse and formation of the pancake-like structure.

  12. Relativistic particle acceleration in plerions

    NASA Technical Reports Server (NTRS)

    Arons, Jonathan; Tavani, Marco

    1994-01-01

    We discuss recent research on the structure and particle acceleration properties of relativistic shock waves in which the magnetic field is transverse to the flow direction in the upstream medium, and whose composition is either pure electrons and positrons or primarily electrons and positrons with an admixture of heavy ions. Particle-in-cell simulation techniques as well as analytic theory have been used to show that such shocks in pure pair plasmas are fully thermalized -- the downstream particle spectra are relativistic Maxwellians at the temperature expected from the jump conditions. On the other hand, shocks containing heavy ions which are a minority constituent by number but which carry most of the energy density in the upstream medium do put approximately 20% of the flow energy into a nonthermal population of pairs downstream, whose distribution in energy space is N(E) varies as E(exp -2), where N(E)dE is the number of particles with energy between E and E+dE. The mechanism of thermalization and particle acceleration is found to be synchrotron maser activity in the shock front, stimulated by the quasi-coherent gyration of the whole particle population as the plasma flowing into the shock reflects from the magnetic field in the shock front. The synchrotron maser modes radiated by the heavy ions are absorbed by the pairs at their (relativistic) cyclotron frequencies, allowing the maximum energy achievable by the pairs to be gamma(sub +/-)m(sub +/-)c squared = m(sub i)c squared gamma(sub 1)/Z(sub i), where gamma(sub 1) is the Lorentz factor of the upstream flow and Z(sub i) is the atomic number of the ions. The shock's spatial structure is shown to contain a series of 'overshoots' in the magnetic field, regions where the gyrating heavy ions compress the magnetic field to levels in excess of the eventual downstream value. This shock model is applied to an interpretation of the structure of the inner regions of the Crab Nebula, in particular to the 'wisps

  13. Relativistic positioning systems: Numerical simulations

    NASA Astrophysics Data System (ADS)

    Puchades Colmenero, Neus

    The position of users located on the Earth's surface or near it may be found with the classic positioning systems (CPS). Certain information broadcast by satellites of global navigation systems, as GPS and GALILEO, may be used for positioning. The CPS are based on the Newtonian formalism, although relativistic post-Newtonian corrections are done when they are necessary. This thesis contributes to the development of a different positioning approach, which is fully relativistic from the beginning. In the relativistic positioning systems (RPS), the space-time position of any user (ship, spacecraft, and so on) can be calculated with the help of four satellites, which broadcast their proper times by means of codified electromagnetic signals. In this thesis, we have simulated satellite 4-tuples of the GPS and GALILEO constellations. If a user receives the signals from four satellites simultaneously, the emission proper times read -after decoding- are the user "emission coordinates". In order to find the user "positioning coordinates", in an appropriate almost inertial reference system, there are two possibilities: (a) the explicit relation between positioning and emission coordinates (broadcast by the satellites) is analytically found or (b) numerical codes are designed to calculate the positioning coordinates from the emission ones. Method (a) is only viable in simple ideal cases, whereas (b) allows us to consider realistic situations. In this thesis, we have designed numerical codes with the essential aim of studying two appropriate RPS, which may be generalized. Sometimes, there are two real users placed in different positions, which receive the same proper times from the same satellites; then, we say that there is bifurcation, and additional data are needed to choose the real user position. In this thesis, bifurcation is studied in detail. We have analyzed in depth two RPS models; in both, it is considered that the satellites move in the Schwarzschild's space

  14. Relativistic stars in f(R) and scalar-tensor theories

    SciTech Connect

    Babichev, Eugeny; Langlois, David

    2010-06-15

    We study relativistic stars in the context of scalar-tensor theories of gravity that try to account for the observed cosmic acceleration and satisfy the local gravity constraints via the chameleon mechanism. More specifically, we consider two types of models: scalar-tensor theories with an inverse power law potential and f(R) theories. Using a relaxation algorithm, we construct numerically static relativistic stars, both for constant energy density configurations and for a polytropic equation of state. We can reach a gravitational potential up to {Phi}{approx}0.3 at the surface of the star, even in f(R) theories with an 'unprotected' curvature singularity. However, we find static configurations only if the pressure does not exceed one third of the energy density, except possibly in a limited region of the star (otherwise, one expects tachyonic instabilities to develop). This constraint is satisfied by realistic equations of state for neutron stars.

  15. Ultrashort-Pulse Child-Langmuir Law in the Quantum and Relativistic Regimes

    SciTech Connect

    Ang, L. K.; Zhang, P.

    2007-04-20

    This Letter presents a consistent quantum and relativistic model of short-pulse Child-Langmuir (CL) law, of which the pulse length {tau} is less than the electron transit time in a gap of spacing D and voltage V. The classical value of the short-pulse CL law is enhanced by a large factor due to quantum effects when the pulse length and the size of the beam are, respectively, in femtosecond duration and nanometer scale. At high voltage larger than the electron rest mass, relativistic effects will suppress the enhancement of short-pulse CL law, which is confirmed by particle-in-cell simulation. When the pulse length is much shorter than the gap transit time, the current density is proportional to V, and to the inverse power of D and {tau}.

  16. The SOFIA experiment: Measurement of 236U fission fragment yields in inverse kinematics

    NASA Astrophysics Data System (ADS)

    Grente, L.; Taïeb, J.; Chatillon, A.; Martin, J.-F.; Pellereau, É.; Boutoux, G.; Gorbinet, T.; Bélier, G.; Laurent, B.; Alvarez-Pol, H.; Ayyad, Y.; Benlliure, J.; Caamaño, M.; Audouin, L.; Casarejos, E.; Cortina-Gil, D.; Farget, F.; Fernández-Domínguez, B.; Heinz, A.; Jurado, B.; Kelić-Heil, A.; Kurz, N.; Lindberg, S.; Löher, B.; Nociforo, C.; Paradela, C.; Pietri, S.; Ramos, D.; Rodriguez-Sanchez, J.-L.; Rodríguez-Tajes, C.; Rossi, D.; Schmidt, K.-H.; Simon, H.; Tassan-Got, L.; Törnqvist, H.; Vargas, J.; Voss, B.; Weick, H.; Yan, Y.

    2016-06-01

    The SOFIA (Studies On FIssion with Aladin) experiment aims at measuring fission-fragments isotopic yields with high accuracy using inverse kinematics at relativistic energies. This experimental technique allows to fully identify the fission fragments in nuclear charge and mass number, thus providing very accurate isotopic yields for low energy fission of a large variety of fissioning systems. This report focuses on the latest results obtained with this set-up concerning electromagnetic-induced fission of 236U.

  17. Fragmentary and incidental behaviour of columns, slabs and crystals

    PubMed Central

    Whiteley, Walter

    2014-01-01

    Between the study of small finite frameworks and infinite incidentally periodic frameworks, we find the real materials which are large, but finite, fragments that fit into the infinite periodic frameworks. To understand these materials, we seek insights from both (i) their analysis as large frameworks with associated geometric and combinatorial properties (including the geometric repetitions) and (ii) embedding them into appropriate infinite periodic structures with motions that may break the periodic structure. A review of real materials identifies a number of examples with a local appearance of ‘unit cells’ which repeat under isometries but perhaps in unusual forms. These examples also refocus attention on several new classes of infinite ‘periodic’ frameworks: (i) columns—three-dimensional structures generated with one repeating isometry and (ii) slabs—three-dimensional structures with two independent repeating translations. With this larger vision of structures to be studied, we find some patterns and partial results that suggest new conjectures as well as many additional open questions. These invite a search for new examples and additional theorems. PMID:24379423

  18. Incidental findings on cone beam computed tomography images.

    PubMed

    Allareddy, Veeratrishul; Vincent, Steven D; Hellstein, John W; Qian, Fang; Smoker, Wendy R K; Ruprecht, Axel

    2012-01-01

    Background. Cone beam computed tomography (CBCT) has gained widespread acceptance in dentistry for a variety of applications. Most dentists who are not radiologists/trained in radiology are generally not familiar with interpretation of anatomical structures and/or pathosis outside their area of primary interest, as often this was not within the scope of their training. Objectives. To assess that the number of incidental findings on a CBCT scan is high both within and outside of the primary area of interest, thereby emphasizing the importance of interpretation of all areas visualized on the scan. Materials and Methods. An oral and maxillofacial radiologist reviewed 1000 CBCT scans (382 males and 618 females) for findings both in- and outside the area of interest. Results. Of the 1000 subjects that were reviewed, 943 scans showed findings in the primary regions of interest and/or outside the regions of interest, and 76 different conditions were visualized in these scans both in and outside the areas of interest. Conclusion. From the wide scope of findings noted on these scans, it can be concluded that it is essential that a person trained in advanced interpretation techniques in radiology interprets cone beam computed tomography scans.

  19. Self-corrected elaboration effects on incidental memory.

    PubMed

    Toyota, Hiroshi

    2004-10-01

    Subjects performed an orienting task involving 3 conditions followed by an unexpected free recall test. The conditions were designed to force 3 types of corrected elaborations: Generated Correction, Chosen Correction, and No Correction. In the Generated Correction condition the subjects were presented with a target word (e.g., Baby) and a bizarre sentence frame (e.g., "____drinks beer.") and asked to correct the target to a congruous word (e.g., Uncle) to make a common sentence. In the Chosen Correction condition, the subjects were presented with a target and its bizarre sentence frame and asked to choose one of the alternative congruous words (e.g., Uncle, Aunt) to make a common sentence. In the No Correction condition, the subjects were presented with a target and its bizarre sentence frame and asked to rate the congruity of each target to its sentence frame. Generated Correction led to a better performance than Chosen Correction and No Correction, but a difference between the last two correction types was not found. These results were interpreted as showing that, by generating correct information, self-corrected elaboration led to facilitation of incidental memory.

  20. Delphinid behavioral responses to incidental mid-frequency active sonar.

    PubMed

    Henderson, E Elizabeth; Smith, Michael H; Gassmann, Martin; Wiggins, Sean M; Douglas, Annie B; Hildebrand, John A

    2014-10-01

    Opportunistic observations of behavioral responses by delphinids to incidental mid-frequency active (MFA) sonar were recorded in the Southern California Bight from 2004 through 2008 using visual focal follows, static hydrophones, and autonomous recorders. Sound pressure levels were calculated between 2 and 8 kHz. Surface behavioral responses were observed in 26 groups from at least three species of 46 groups out of five species encountered during MFA sonar incidents. Responses included changes in behavioral state or direction of travel, changes in vocalization rates and call intensity, or a lack of vocalizations while MFA sonar occurred. However, 46% of focal groups not exposed to sonar also changed their behavior, and 43% of focal groups exposed to sonar did not change their behavior. Mean peak sound pressure levels when a behavioral response occurred were around 122 dB re: 1 μPa. Acoustic localizations of dolphin groups exhibiting a response gave insight into nighttime movement patterns and provided evidence that impacts of sonar may be mediated by behavioral state. The lack of response in some cases may indicate a tolerance of or habituation to MFA sonar by local populations; however, the responses that occur at lower received levels may point to some sensitization as well.

  1. RELATIVISTIC HEAVY ION COLLISIONS: EXPERIMENT

    SciTech Connect

    Friedlander, Erwin M.; Heckman, Harry H.

    1982-04-01

    Relativistic heavy ion physics began as a 'no man's land' between particle and nuclear physics, with both sides frowning upon it as 'unclean', because on one hand, hadronic interactions and particle production cloud nuclear structure effects, while on the other, the baryonic environment complicates the interpretation of production experiments. They have attempted to review here the experimental evidence on RHI collisions from the point of view that it represents a new endeavor in the understanding of strong interaction physics. Such an approach appears increasingly justified; first, by the accumulation of data and observations of new features of hadronic interactions that could not have been detected outside a baryonic environment; second, by the maturation of the field owing to the advances made over the past several years in experimental inquiries on particle production by RHI, including pions, kaons, hyperons, and searches for antiprotons; and third, by the steady and progressive increase in the energy and mass ranges of light nuclear beams that have become available to the experiment; indeed the energy range has widened from the {approx} 0.2 to 2 AGeV at the Bevalac to {approx}4 AGeV at Dubna and recently, to the quantum jump in energies to {approx} 1000 equivalent AGeV at the CERN PS-ISR. Accompanying these expansions in the energy frontier are the immediate prospects for very heavy ion beams at the Bevalac up to, and including, 1 AGeV {sup 238}U, thereby extending the 'mass frontier' to its ultimate extent.

  2. The Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Fischer, Wolfram

    The Relativistic Heavy Ion Collider (RHIC), shown in Fig. 1, was build to study the interactions of quarks and gluons at high energies [Harrison, Ludlam and Ozaki (2003)]. The theory of Quantum Chromodynamics (QCD) describes these interactions. One of the main goals for the RHIC experiments was the creation and study of the Quark-Gluon Plasma (QGP), which was expected to be formed after the collision of heavy ions at a temperature of approximately 2 trillion kelvin (or equivalently an energy of 150 MeV). The QGP is the substance which existed only a few microseconds after the Big Bang. The QGP was anticipated to be weakly interacting like a gas but turned out to be strongly interacting and more like a liquid. Among its unusual properties is its extremely low viscosity [Auerbach and Schlomo (2009)], which makes the QGP the substance closest to a perfect liquid known to date. The QGP is opaque to moderate energy quarks and gluons leading to a phenomenon called jet quenching, where of a jet and its recoil jet only one is observable and the other suppressed after traversing and interacting with the QGP [Jacak and Müller (2012)]...

  3. Observation of relativistic antihydrogen atoms

    SciTech Connect

    Blanford, Glenn DelFosse

    1998-01-01

    An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 < p < 9 GeV/c) antiprotons and a jet of molecular hydrogen gas. Since the neutral antihydrogen does not bend in the antiproton source magnets, the detectors could be located far from the interaction point on a beamline tangent to the storage ring. The detection of the antihydrogen is accomplished by ionizing the atoms far from the interaction point. The positron is deflected by a magnetic spectrometer and detected, as are the back to back photons resulting from its annihilation. The antiproton travels a distance long enough for its momentum and time of flight to be measured accurately. A statistically significant sample of 101 antihydrogen atoms has been observed. A measurement of the cross section for {bar H}{sup 0} production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e{sup +} e{sup -} pair creation near a nucleus with the e{sup +} being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure.

  4. Observation of relativistic antihydrogen atoms

    SciTech Connect

    Blanford, G.D.

    1997-12-31

    An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 < p < 9 GeV/c) antiprotons and a jet of molecular hydrogen gas. Since the neutral antihydrogen does not bend in the antiproton source magnets, the detectors could be located far from the interaction point on a beamline tangent to the storage ring. The detection of the antihydrogen is accomplished by ionizing the atoms far from the interaction point. The positron is deflected by a magnetic spectrometer and detected, as are the back to back photons resulting from its annihilation. The antiproton travels a distance long enough for its momentum and time of flight to be measured accurately. A statistically significant sample of 101 antihydrogen atoms has been observed. A measurement of the cross section for {anti H}{sup 0} production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e{sup +}e{sup {minus}} pair creation near a nucleus with the e{sup +} being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment`s results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure.

  5. Observation of relativistic antihydrogen atoms

    NASA Astrophysics Data System (ADS)

    Blanford, Glenn Delfosse, Jr.

    1997-09-01

    An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 < p < 9 GeV/c) antiprotons and a jet of molecular hydrogen gas. Since the neutral antihydrogen does not bend in the antiproton source magnets, the detectors could be located far from the interaction point on a beamline tangent to the storage ring. The detection of the antihydrogen is accomplished by ionizing the atoms far from the interaction point. The positron is deflected by a magnetic spectrometer and detected, as are the back to back photons resulting from its annihilation. The antiproton travels a distance long enough for its momentum and time of flight to be measured accurately. A statistically significant sample of 101 antihydrogen atoms has been observed. A measurement of the cross section for /bar Ho production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e+e/sp- pair creation near a nucleus with the e+ being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure.

  6. Detonation waves in relativistic hydrodynamics

    SciTech Connect

    Cissoko, M. )

    1992-02-15

    This paper is concerned with an algebraic study of the equations of detonation waves in relativistic hydrodynamics taking into account the pressure and the energy of thermal radiation. A new approach to shock and detonation wavefronts is outlined. The fluid under consideration is assumed to be perfect (nonviscous and nonconducting) and to obey the following equation of state: {ital p}=({gamma}{minus}1){rho} where {ital p}, {rho}, and {gamma} are the pressure, the total energy density, and the adiabatic index, respectively. The solutions of the equations of detonation waves are reduced to the problem of finding physically acceptable roots of a quadratic polynomial {Pi}({ital X}) where {ital X} is the ratio {tau}/{tau}{sub 0} of dynamical volumes behind and ahead of the detonation wave. The existence and the locations of zeros of this polynomial allow it to be shown that if the equation of state of the burnt fluid is known then the variables characterizing the unburnt fluid obey well-defined physical relations.

  7. Relativistic Dipole Matrix Element Zeros

    NASA Astrophysics Data System (ADS)

    Lajohn, L. A.; Pratt, R. H.

    2002-05-01

    There is a special class of relativistic high energy dipole matrix element zeros (RZ), whose positions with respect to photon energy ω , only depend on the bound state l quantum number according to ω^0=mc^2/(l_b+1) (independent of primary quantum number n, nuclear charge Z, central potential V and dipole retardation). These RZ only occur in (n,l_b,j_b)arrow (ɛ , l_b+1,j_b) transitions such as ns_1/2arrow ɛ p_1/2; np_3/2arrow ɛ d_3/2: nd_5/2arrow ɛ f_5/2 etc. The nonrelativistic limit of these matrix elements can be established explicitly in the Coulomb case. Within the general matrix element formalism (such as that in [1]); when |κ | is substituted for γ in analytic expressions for matrix elements, the zeros remain, but ω^0 now becomes dependent on n and Z. When the reduction to nonrelativistic form is completed by application of the low energy approximation ω mc^2 mc^2, the zeros disappear. This nonzero behavior was noted in nonrelativistic dipole Coulomb matrix elements by Fano and Cooper [2] and later proven by Oh and Pratt[3]. (J. H. Scofield, Phys. Rev. A 40), 3054 (1989 (U. Fano and J. W. Cooper, Rev. Mod. Phys. 40), 441 (1968). (D. Oh and R. H. Pratt, Phys. Rev. A 34), 2486 (1986); 37, 1524 (1988); 45, 1583 (1992).

  8. Birkhoff's equations and geometrical theory of rotational relativistic system

    NASA Astrophysics Data System (ADS)

    Luo, Shao-kai; Chen, Xiang-wei; Fu, Jing-li

    2001-04-01

    The Birkhoffian and Birkhoff's functions of a rotational relativistic system are constructed, the Pfaff action of rotational relativistic system is defined, the Pfaff-Birkhoff principle of a rotational relativistic system is given and the Pfaff-Birkhoff-D'Alembert principles and Birkhoff's equations of rotational relativistic system are constructed. The geometrical description of a rotational relativistic system is studied and the exact properties of Birkhoff's equations and their forms on R×T*M for a rotational relativistic system are obtained. The global analysis of Birkhoff's equations for a rotational relativistic system is studied, the global properties of autonomous, semi-autonomous and non-autonomous rotational relativistic Birkhoff's equations and the geometrical properties of energy change for rotational relativistic Birkhoff's equations are given.

  9. 3D Relativistic MHD Simulations of Magnetized Spine-Sheath Relativistic Jets

    NASA Technical Reports Server (NTRS)

    Mizuno, Yosuke; Hardee, Philip E.; Nishikawa, Ken-Ichi

    2007-01-01

    We have performed numerical simulations of weakly and strongly magnetized relativistic jets embedded in a weakly and strongly magnetized stationary or mildly relativistic (0.5c) sheath using the RAISHIN code. In the numerical simulations a jet with Lorentz factor gamma=2.5 is precessed to break the initial equilibrium configuration. Results of the numerical simulations are compared to theoretical predictions from a normal mode-analysis of the linearized RMHD equations describing a uniform axially magnetized cylindrical relativistic jet embedded in a uniform axially magnetized moving sheath. The prediction of increased stability of a weakly-magnetized system with mildly relativistic sheath flow to Kelvin-Helmholtz instabilities and the stabilization of a strongly-magnetized system with mildly relativistic sheath flow is confirmed by the numerical simulations.

  10. Stress inversion assumptions review

    NASA Astrophysics Data System (ADS)

    Lejri, Mostfa; Maerten, Frantz; Maerten, Laurent; Joonnenkindt, Jean Pierre; Soliva, Roger

    2014-05-01

    Wallace (1951) and Bott (1959) were the first to introduce the idea that the slip on each fault surface has the same direction and sense as the maximum shear stress resolved on that surface. This hypothesis are based on the assumptions that (i) faults are planar, (ii) blocks are rigid, (iii) neither stress perturbations nor block rotations along fault surfaces occur and (iv), the applied stress state is uniform. However, this simplified hypothesis is questionable since complex fault geometries, heterogeneous fault slip directions, evidences of stress perturbations in microstructures and block rotations along fault surfaces were reported in the literature. Earlier numerical geomechanical models confirmed that the striation lines (slip vectors) are not necessarily parallel to the maximum shear stress vector but is consistent with local stress perturbations. This leads us to ask as to what extent the Wallace and Bott simplifications are reliable as a basis hypothesis for stress inversion. In this presentation, a geomechanical multi-parametric study using 3D boundary element method (BEM), covering (i) fault geometries such as intersected faults or corrugated fault surfaces, (ii) the full range of Andersonian state of stress, (iii) fault friction, (iv) half space effect and (v), rock properties, is performed in order to understand the effect of each parameter on the angular misfit between geomechanical slip vectors and the resolved shear stresses. It is shown that significant angular misfits can be found under specific configurations and therefore we conclude that stress inversions based on the Wallace-Bott hypothesis might sometime give results that should be interpreted with care. Major observations are that (i) applying optimum tectonic stress conditions on complex fault geometries can increase the angular misfit, (ii) elastic material properties, combined to half-space effect, can enhance this effect, and (iii) an increase of the sliding friction leads to a

  11. Inverse magnetorheological fluids.

    PubMed

    Rodríguez-Arco, L; López-López, M T; Zubarev, A Y; Gdula, K; Durán, J D G

    2014-09-01

    We report a new kind of field-responsive fluid consisting of suspensions of diamagnetic (DM) and ferromagnetic (FM) microparticles in ferrofluids. We designate them as inverse magnetorheological (IMR) fluids for analogy with inverse ferrofluids (IFFs). Observations on the particle self-assembly in IMR fluids upon magnetic field application showed that DM and FM microparticles were assembled into alternating chains oriented along the field direction. We explain such assembly on the basis of the dipolar interaction energy between particles. We also present results on the rheological properties of IMR fluids and, for comparison, those of IFFs and bidispersed magnetorheological (MR) fluids. Interestingly, we found that upon magnetic field application, the rheological properties of IMR fluids were enhanced with respect to bidispersed MR fluids with the same FM particle concentration, by an amount greater than the sum of the isolated contribution of DM particles. Furthermore, the field-induced yield stress was moderately increased when up to 30% of the total FM particle content was replaced with DM particles. Beyond this point, the dependence of the yield stress on the DM content was non-monotonic, as expected for FM concentrations decreasing to zero. We explain these synergistic results by two separate phenomena: the formation of exclusion areas for FM particles due to the perturbation of the magnetic field by DM particles and the dipole-dipole interaction between DM and FM particles, which enhances the field-induced structures. Based on the second phenomenon, we present a theoretical model for the yield stress that semi-quantitatively predicts the experimental results. PMID:25022363

  12. Wavelet Sparse Approximate Inverse Preconditioners

    NASA Technical Reports Server (NTRS)

    Chan, Tony F.; Tang, W.-P.; Wan, W. L.

    1996-01-01

    There is an increasing interest in using sparse approximate inverses as preconditioners for Krylov subspace iterative methods. Recent studies of Grote and Huckle and Chow and Saad also show that sparse approximate inverse preconditioner can be effective for a variety of matrices, e.g. Harwell-Boeing collections. Nonetheless a drawback is that it requires rapid decay of the inverse entries so that sparse approximate inverse is possible. However, for the class of matrices that, come from elliptic PDE problems, this assumption may not necessarily hold. Our main idea is to look for a basis, other than the standard one, such that a sparse representation of the inverse is feasible. A crucial observation is that the kind of matrices we are interested in typically have a piecewise smooth inverse. We exploit this fact, by applying wavelet techniques to construct a better sparse approximate inverse in the wavelet basis. We shall justify theoretically and numerically that our approach is effective for matrices with smooth inverse. We emphasize that in this paper we have only presented the idea of wavelet approximate inverses and demonstrated its potential but have not yet developed a highly refined and efficient algorithm.

  13. Inverse problem for Bremsstrahlung radiation

    SciTech Connect

    Voss, K.E.; Fisch, N.J.

    1991-10-01

    For certain predominantly one-dimensional distribution functions, an analytic inversion has been found which yields the velocity distribution of superthermal electrons given their Bremsstrahlung radiation. 5 refs.

  14. Probing Acceleration and Turbulence at Relativistic Shocks in Blazar Jets

    NASA Astrophysics Data System (ADS)

    Baring, Matthew G.; Böttcher, Markus; Summerlin, Errol J.

    2016-09-01

    Diffusive shock acceleration (DSA) at relativistic shocks is widely thought to be an important acceleration mechanism in various astrophysical jet sources, including radio-loud active galactic nuclei such as blazars. Such acceleration can produce the non-thermal particles that emit the broadband continuum radiation that is detected from extragalactic jets. An important recent development for blazar science is the ability of Fermi-LAT spectroscopy to pin down the shape of the distribution of the underlying non-thermal particle population. This paper highlights how multi-wavelength spectra spanning optical to X-ray to gamma-ray bands can be used to probe diffusive acceleration in relativistic, oblique, magnetohydrodynamic (MHD) shocks in blazar jets. Diagnostics on the MHD turbulence near such shocks are obtained using thermal and non-thermal particle distributions resulting from detailed Monte Carlo simulations of DSA. These probes are afforded by the characteristic property that the synchrotron νFν peak energy does not appear in the gamma-ray band above 100 MeV. We investigate self-consistently the radiative synchrotron and inverse Compton signatures of the simulated particle distributions. Important constraints on the diffusive mean free paths of electrons, and the level of electromagnetic field turbulence are identified for three different case study blazars, Mrk 501, BL Lacertae and AO 0235+164. The X-ray excess of AO 0235+164 in a flare state can be modelled as the signature of bulk Compton scattering of external radiation fields, thereby tightly constraining the energy-dependence of the diffusion coefficient for electrons. The concomitant interpretations that turbulence levels decline with remoteness from jet shocks, and the probable significant role for non-gyroresonant diffusion, are posited.

  15. Generation of high-energy neutron beam by fragmentation of relativistic heavy nuclei

    NASA Astrophysics Data System (ADS)

    Yurevich, Vladimir

    2016-09-01

    The phenomenon of multiple production of neutrons in reactions with heavy nuclei induced by high-energy protons and light nuclei is analyzed using a Moving Source Model. The Lorentz transformation of the obtained neutron distributions is used to study the neutron characteristics in the inverse kinematics where relativistic heavy nuclei bombard a light-mass target. The neutron beam generated at 0∘has a Gaussian shape with a maximum at the energy of the projectile nucleons and an energy resolution σE/E < 4% above 6 GeV.

  16. Recent experimental results from a long-pulse J-band relativistic klystron amplifier developmental effort

    SciTech Connect

    Kato, K.G.; Crouch, D.D.; Sar, D.R.; Speciale, R.A.; Carlsten, B.E.; Fazio, M.V.; Haynes, W.B.; Stringfield, R.M.

    1994-12-31

    Recent experimental results, supporting simulations, and design modeling are presented from a developmental effort to a produce a long pulse ({approximately}1{mu}s) J-band (5.85-8.2 GHz) relativistic klystron amplifier (RKA) of the high current NRL genealogy. This RKA is designed to operate at approximately 6.6 GHz, with a desired RF output {approximately}700 MW. Conversion of electron beam energy to microwave energy is obtained by a mock magnetically insulated coaxial converter which, in various incarnations, can be made to be either a cavity gap extractor or an inverse cathode.

  17. Imbalanced relativistic force-free magnetohydrodynamic turbulence

    SciTech Connect

    Cho, Jungyeon; Lazarian, A.

    2014-01-01

    When magnetic energy density is much larger than that of matter, as in pulsar/black hole magnetospheres, the medium becomes force-free and we need relativity to describe it. As in non-relativistic magnetohydrodynamics (MHD), Alfvénic MHD turbulence in the relativistic limit can be described by interactions of counter-traveling wave packets. In this paper, we numerically study strong imbalanced MHD turbulence in such environments. Here, imbalanced turbulence means the waves traveling in one direction (dominant waves) have higher amplitudes than the opposite-traveling waves (sub-dominant waves). We find that (1) spectrum of the dominant waves is steeper than that of sub-dominant waves, (2) the anisotropy of the dominant waves is weaker than that of sub-dominant waves, and (3) the dependence of the ratio of magnetic energy densities of dominant and sub-dominant waves on the ratio of energy injection rates is steeper than quadratic (i.e., b{sub +}{sup 2}/b{sub −}{sup 2}∝(ϵ{sub +}/ϵ{sub −}){sup n} with n > 2). These results are consistent with those obtained for imbalanced non-relativistic Alfvénic turbulence. This corresponds well to the earlier reported similarity of the relativistic and non-relativistic balanced magnetic turbulence.

  18. Relativistic generation of vortex and magnetic field

    SciTech Connect

    Mahajan, S. M.; Yoshida, Z.

    2011-05-15

    The implications of the recently demonstrated relativistic mechanism for generating generalized vorticity in purely ideal dynamics [Mahajan and Yoshida, Phys. Rev. Lett. 105, 095005 (2010)] are worked out. The said mechanism has its origin in the space-time distortion caused by the demands of special relativity; these distortions break the topological constraint (conservation of generalized helicity) forbidding the emergence of magnetic field (a generalized vorticity) in an ideal nonrelativistic dynamics. After delineating the steps in the ''evolution'' of vortex dynamics, as the physical system goes from a nonrelativistic to a relativistically fast and hot plasma, a simple theory is developed to disentangle the two distinct components comprising the generalized vorticity--the magnetic field and the thermal-kinetic vorticity. The ''strength'' of the new universal mechanism is, then, estimated for a few representative cases; in particular, the level of seed fields, created in the cosmic setting of the early hot universe filled with relativistic particle-antiparticle pairs (up to the end of the electron-positron era), are computed. Possible applications of the mechanism in intense laser produced plasmas are also explored. It is suggested that highly relativistic laser plasma could provide a laboratory for testing the essence of the relativistic drive.

  19. Relativistic mixtures of charged and uncharged particles

    SciTech Connect

    Kremer, Gilberto M.

    2014-01-14

    Mixtures of relativistic gases within the framework of Boltzmann equation are analyzed. Three systems are considered. The first one refers to a mixture of uncharged particles by using Grad’s moment method, where the relativistic mixture is characterized by the moments of the distribution functions: particle four-flows, energy-momentum tensors, and third-order moment tensors. In the second Fick’s law for a mixture of relativistic gases of non-disparate rest masses in a Schwarzschild metric are derived from an extension of Marle and McCormack model equations applied to a relativistic truncated Grad’s distribution function, where it is shown the dependence of the diffusion coefficient on the gravitational potential. The third one consists in the derivation of the relativistic laws of Ohm and Fourier for a binary mixtures of electrons with protons and electrons with photons subjected to external electromagnetic fields and in presence of gravitational fields by using the Anderson and Witting model of the Boltzmann equation.

  20. Actionable, pathogenic incidental findings in 1,000 participants' exomes.

    PubMed

    Dorschner, Michael O; Amendola, Laura M; Turner, Emily H; Robertson, Peggy D; Shirts, Brian H; Gallego, Carlos J; Bennett, Robin L; Jones, Kelly L; Tokita, Mari J; Bennett, James T; Kim, Jerry H; Rosenthal, Elisabeth A; Kim, Daniel S; Tabor, Holly K; Bamshad, Michael J; Motulsky, Arno G; Scott, C Ronald; Pritchard, Colin C; Walsh, Tom; Burke, Wylie; Raskind, Wendy H; Byers, Peter; Hisama, Fuki M; Nickerson, Deborah A; Jarvik, Gail P

    2013-10-01

    The incorporation of genomics into medicine is stimulating interest on the return of incidental findings (IFs) from exome and genome sequencing. However, no large-scale study has yet estimated the number of expected actionable findings per individual; therefore, we classified actionable pathogenic single-nucleotide variants in 500 European- and 500 African-descent participants randomly selected from the National Heart, Lung, and Blood Institute Exome Sequencing Project. The 1,000 individuals were screened for variants in 114 genes selected by an expert panel for their association with medically actionable genetic conditions possibly undiagnosed in adults. Among the 1,000 participants, 585 instances of 239 unique variants were identified as disease causing in the Human Gene Mutation Database (HGMD). The primary literature supporting the variants' pathogenicity was reviewed. Of the identified IFs, only 16 unique autosomal-dominant variants in 17 individuals were assessed to be pathogenic or likely pathogenic, and one participant had two pathogenic variants for an autosomal-recessive disease. Furthermore, one pathogenic and four likely pathogenic variants not listed as disease causing in HGMD were identified. These data can provide an estimate of the frequency (∼3.4% for European descent and ∼1.2% for African descent) of the high-penetrance actionable pathogenic or likely pathogenic variants in adults. The 23 participants with pathogenic or likely pathogenic variants were disproportionately of European (17) versus African (6) descent. The process of classifying these variants underscores the need for a more comprehensive and diverse centralized resource to provide curated information on pathogenicity for clinical use to minimize health disparities in genomic medicine.

  1. Actionable, Pathogenic Incidental Findings in 1,000 Participants’ Exomes

    PubMed Central

    Dorschner, Michael O.; Amendola, Laura M.; Turner, Emily H.; Robertson, Peggy D.; Shirts, Brian H.; Gallego, Carlos J.; Bennett, Robin L.; Jones, Kelly L.; Tokita, Mari J.; Bennett, James T.; Kim, Jerry H.; Rosenthal, Elisabeth A.; Kim, Daniel S.; Tabor, Holly K.; Bamshad, Michael J.; Motulsky, Arno G.; Scott, C. Ronald; Pritchard, Colin C.; Walsh, Tom; Burke, Wylie; Raskind, Wendy H.; Byers, Peter; Hisama, Fuki M.; Nickerson, Deborah A.; Jarvik, Gail P.

    2013-01-01

    The incorporation of genomics into medicine is stimulating interest on the return of incidental findings (IFs) from exome and genome sequencing. However, no large-scale study has yet estimated the number of expected actionable findings per individual; therefore, we classified actionable pathogenic single-nucleotide variants in 500 European- and 500 African-descent participants randomly selected from the National Heart, Lung, and Blood Institute Exome Sequencing Project. The 1,000 individuals were screened for variants in 114 genes selected by an expert panel for their association with medically actionable genetic conditions possibly undiagnosed in adults. Among the 1,000 participants, 585 instances of 239 unique variants were identified as disease causing in the Human Gene Mutation Database (HGMD). The primary literature supporting the variants’ pathogenicity was reviewed. Of the identified IFs, only 16 unique autosomal-dominant variants in 17 individuals were assessed to be pathogenic or likely pathogenic, and one participant had two pathogenic variants for an autosomal-recessive disease. Furthermore, one pathogenic and four likely pathogenic variants not listed as disease causing in HGMD were identified. These data can provide an estimate of the frequency (∼3.4% for European descent and ∼1.2% for African descent) of the high-penetrance actionable pathogenic or likely pathogenic variants in adults. The 23 participants with pathogenic or likely pathogenic variants were disproportionately of European (17) versus African (6) descent. The process of classifying these variants underscores the need for a more comprehensive and diverse centralized resource to provide curated information on pathogenicity for clinical use to minimize health disparities in genomic medicine. PMID:24055113

  2. Reduced striatal tyrosine hydroxylase in incidental Lewy body disease

    PubMed Central

    Adler, Charles H.; Sue, Lucia I.; Peirce, Jeffrey B.; Bachalakuri, Jyothi; Dalsing-Hernandez, Jessica E.; Lue, Lih Fen; Caviness, John N.; Connor, Donald J.; Sabbagh, Marwan N.; Walker, Douglas G.

    2009-01-01

    Incidental Lewy body disease (ILBD) is the term used when Lewy bodies are found in the nervous system of subjects without clinically documented parkinsonism or dementia. The prevalence of ILBD in the elderly population has been estimated at between 3.8 and 30%, depending on subject age and anatomical site of sampling. It has been speculated that ILBD represents the preclinical stage of Parkinson’s disease (PD) and/or dementia with Lewy bodies (DLB). Studies of ILBD could potentially identify early diagnostic signs of these disorders. At present, however, it is impossible to know whether ILBD is a precursor to PD or DLB or is just a benign finding of normal aging. We hypothesized that, if ILBD represents an early stage of PD or DLB, it should be associated with depletion of striatal dopaminergic markers. Eleven subjects with ILBD and 27 control subjects were studied. The ILBD subjects ranged in age from 74 to 96 years (mean 86.5) while the control subjects’ age ranged from 75 to 102 years (mean 86.7). Controls and subjects did not differ in terms of age, postmortem interval, gender distribution, medical history conditions, brain weight, neuritic plaque density or Braak neurofibrillary stage. Quantitative ELISA measurement of striatal tyrosine hydroxylase (TH), the principal enzyme for dopamine synthesis, showed a 49.8% (P = 0.01) reduction in ILBD cases, as compared with control cases. The finding suggests that ILBD is not a benign condition but is likely a precursor to PD and/or DLB. PMID:17985144

  3. Incidental findings from clinical sequencing in Greece: reporting experts' attitudes.

    PubMed

    Gourna, E G; Armstrong, N; Wallace, S E

    2014-10-01

    Unprecedented progress in sequencing technologies and decreasing cost have brought genomic testing into the clinical setting. At the same time, the debate in the literature concerning the return of incidental findings (IFs) has made this an important issue internationally. These developments reflect a shift in genetics that will also affect smaller countries, such as Greece, that are just starting to implement these technologies and may look to other countries for examples of good practice. Ten in-depth interviews were conducted with Greek experts in clinical sequencing. Previous experiences and attitudes toward IFs and clinical sequencing were investigated as well as views on the existing policy regarding managing genetic information generated through testing. . Interviews were analysed using thematic analysis. All participants reported the lack of any legal or other supportive mechanism. IFs are currently managed at a "local" level, i.e. within the clinic or the laboratory in an ad hoc way. All participants thought that clinically valid and actionable IFs should be returned, but always with caution and in respect to patients' wishes, although several experts reported returning IFs according to their clinical discretion. Experts reported that most patients ask for all tests available but they felt that more counselling is needed to understand and manage genetic information. Due to the lack of any supporting mechanisms, professionals in Greece, even those with established experience in the field of genetic and genomic testing, have difficulties dealing with IFs. All experts agreed that it is now time, before the full integration of genomic testing into everyday clinical practice, for guidance to help Greek physicians work with patients and their families when IFs are discovered. PMID:25048384

  4. Towards a European consensus for reporting incidental findings during clinical NGS testing.

    PubMed

    Hehir-Kwa, Jayne Y; Claustres, Mireille; Hastings, Ros J; van Ravenswaaij-Arts, Conny; Christenhusz, Gabrielle; Genuardi, Maurizio; Melegh, Béla; Cambon-Thomsen, Anne; Patsalis, Philippos; Vermeesch, Joris; Cornel, Martina C; Searle, Beverly; Palotie, Aarno; Capoluongo, Ettore; Peterlin, Borut; Estivill, Xavier; Robinson, Peter N

    2015-12-01

    In 2013, the American College of Medical Genetics (ACMG) examined the issue of incidental findings in whole exome and whole genome sequencing, and introduced recommendations to search for, evaluate and report medically actionable variants in a set of 56 genes. At a debate held during the 2014 European Society for Human Genetics Conference (ESHG) in Milan, Italy, the first author of that paper presented this view in a debate session that did not end with a conclusive vote from the mainly European audience for or against reporting back actionable incidental findings. In this meeting report, we elaborate on the discussions held during a special meeting hosted at the ESHG in 2013 from posing the question 'How to reach a (European) consensus on reporting incidental findings and unclassified variants in diagnostic next generation sequencing'. We ask whether an European consensus exists on the reporting of incidental findings in genome diagnostics, and present a series of key issues that require discussion at both a national and European level in order to develop recommendations for handling incidental findings and unclassified variants in line with the legal and cultural particularities of individual European member states.

  5. Modular theory of inverse systems

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The relationship between multivariable zeros and inverse systems was explored. A definition of zero module is given in such a way that it is basis independent. The existence of essential right and left inverses were established. The way in which the abstract zero module captured previous definitions of multivariable zeros is explained and examples are presented.

  6. Inversion exercises inspired by mechanics

    NASA Astrophysics Data System (ADS)

    Groetsch, C. W.

    2016-02-01

    An elementary calculus transform, inspired by the centroid and gyration radius, is introduced as a prelude to the study of more advanced transforms. Analysis of the transform, including its inversion, makes use of several key concepts from basic calculus and exercises in the application and inversion of the transform provide practice in the use of technology in calculus.

  7. Exact quantisation of the relativistic Hopfield model

    NASA Astrophysics Data System (ADS)

    Belgiorno, F.; Cacciatori, S. L.; Dalla Piazza, F.; Doronzo, M.

    2016-11-01

    We investigate the quantisation in the Heisenberg representation of a relativistically covariant version of the Hopfield model for dielectric media, which entails the interaction of the quantum electromagnetic field with the matter dipole fields, represented by a mesoscopic polarisation field. A full quantisation of the model is provided in a covariant gauge, with the aim of maintaining explicit relativistic covariance. Breaking of the Lorentz invariance due to the intrinsic presence in the model of a preferred reference frame is also taken into account. Relativistic covariance forces us to deal with the unphysical (scalar and longitudinal) components of the fields, furthermore it introduces, in a more tricky form, the well-known dipole ghost of standard QED in a covariant gauge. In order to correctly dispose of this contribution, we implement a generalised Lautrup trick. Furthermore, causality and the relation of the model with the Wightman axioms are also discussed.

  8. Maximum entropy principle and relativistic hydrodynamics

    NASA Astrophysics Data System (ADS)

    van Weert, Ch. G.

    1982-04-01

    A relativistic theory of hydrodynamics applicable beyond the hydrodynamic regime is developed on the basis of the maximum entropy principle. This allows the construction of a unique statistical operator representing the state of the system as specified by the values of the hydrodynamical densities. Special attention is paid to the thermodynamic limit and the virial theorem which leads to an expression for the pressure in terms of the field-theoretic energymomentum tensor of Coleman and Jackiw. It is argued that outside the hydrodynamic regime the notion of a local Gibbs relation, as usually postulated, must be abandoned in general. In the nontext of the linear approximation, the memory-retaining and non-local generalizations of the relativistic Navier-Stokes equations are derived from the underlying Heisenberg equations of motion. The formal similarity to the Zwanzig-Mori description of non-relativistic fluids is expounded.

  9. Viscous photons in relativistic heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Dion, Maxime; Paquet, Jean-François; Schenke, Björn; Young, Clint; Jeon, Sangyong; Gale, Charles

    2011-12-01

    Theoretical studies of the production of real thermal photons in relativistic heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) are performed. The space-time evolution of the colliding system is modelled using music, a 3+1D relativistic hydrodynamic simulation, using both its ideal and viscous versions. The inclusive spectrum and its azimuthal angular anisotropy are studied separately, and the relative contributions of the different photon sources are highlighted. It is shown that the photon v2 coefficient is especially sensitive to the details of the microscopic dynamics like the equation of state, the ratio of shear viscosity over entropy density, η/s, and to the morphology of the initial state.

  10. Skyrme forces versus relativistic models: Reexamining instabilities

    SciTech Connect

    Dutra, M.; Lourenco, O.; Delfino, A.; Sa Martins, J. S.; Providencia, C.; Avancini, S. S.; Menezes, D. P.

    2008-03-15

    Experimental constraints are useful tools in helping to decide, among a number of candidates, which is the more suitable equation of state for nuclear matter. In this work we compare nonrelativistic Skyrme-type and relativistic Walecka-type models when they are used to describe processes related to binary system instabilities and phases coexistence. In general, nonrelativistic and relativistic models predict somewhat different behaviors, but we found that one of the parametrizations of the density-dependent hadronic model shows some similarities with nonrelativistic models in many of the features addressed in our investigation. We have checked that, once experimental data obtained in heavy-ion collisions are extrapolated to account for symmetric and neutron matter, some of the models discussed in the present work, both relativistic and nonrelativistic, should be ruled out.

  11. Corrugation of Relativistic Magnetized Shock Waves

    NASA Astrophysics Data System (ADS)

    Lemoine, Martin; Ramos, Oscar; Gremillet, Laurent

    2016-08-01

    As a shock front interacts with turbulence it develops corrugation, which induces outgoing wave modes in the downstream plasma. For a fast shock wave, the incoming wave modes can either be fast magnetosonic waves originating downstream, outrunning the shock, or eigenmodes of the upstream plasma drifting through the shock. Using linear perturbation theory in relativistic MHD, this paper provides a general analysis of the corrugation of relativistic magnetized fast shock waves resulting from their interaction with small amplitude disturbances. Transfer functions characterizing the linear response for each of the outgoing modes are calculated as a function of the magnetization of the upstream medium and as a function of the nature of the incoming wave. Interestingly, if the latter is an eigenmode of the upstream plasma, we find that there exists a resonance at which the (linear) response of the shock becomes large or even diverges. This result may have profound consequences on the phenomenology of astrophysical relativistic magnetized shock waves.

  12. Relativistic spin precession in the double pulsar.

    PubMed

    Breton, Rene P; Kaspi, Victoria M; Kramer, Michael; McLaughlin, Maura A; Lyutikov, Maxim; Ransom, Scott M; Stairs, Ingrid H; Ferdman, Robert D; Camilo, Fernando; Possenti, Andrea

    2008-07-01

    The double pulsar PSR J0737-3039A/B consists of two neutron stars in a highly relativistic orbit that displays a roughly 30-second eclipse when pulsar A passes behind pulsar B. Describing this eclipse of pulsar A as due to absorption occurring in the magnetosphere of pulsar B, we successfully used a simple geometric model to characterize the observed changing eclipse morphology and to measure the relativistic precession of pulsar B's spin axis around the total orbital angular momentum. This provides a test of general relativity and alternative theories of gravity in the strong-field regime. Our measured relativistic spin precession rate of 4.77 degrees (-0 degrees .65)(+0 degrees .66) per year (68% confidence level) is consistent with that predicted by general relativity within an uncertainty of 13%.

  13. Relativistic quantum information and time machines

    NASA Astrophysics Data System (ADS)

    Ralph, Timothy C.; Downes, Tony G.

    2012-01-01

    Relativistic quantum information combines the informational approach to understanding and using quantum mechanical systems - quantum information - with the relativistic view of the Universe. In this introductory review we examine key results to emerge from this new field of research in physics and discuss future directions. A particularly active area recently has been the question of what happens when quantum systems interact with general relativistic closed timelike curves - effectively time machines. We discuss two different approaches that have been suggested for modelling such situations. It is argued that the approach based on matching the density operator of the quantum state between the future and past most consistently avoids the paradoxes usually associated with time travel.

  14. Comparative analysis of theories of relativistic photoionization

    NASA Astrophysics Data System (ADS)

    Hafizi, Bahman; Gordon, Daniel; Palastro, John

    2015-11-01

    Laser-plasma experiments routinely rely on photoionization for plasma formation. For large laser intensities or for high-Z atoms relativistic effects become important. We investigate a unique regime of relativistic photoionization from high-Z atoms where relativistic effects modify both the bound and continuum electronic states. Theories of photoionization are based on the imaginary time method and the S-matrix method, amongst others. We compare the results of these approaches for both the Dirac and the Klein-Gordon equations. Analytical results for the momentum distribution of ejected electrons and ionization rate are presented and compared with those from numerical solutions. Work supported by the Department of Energy and the NRL Base Program.

  15. Relativistic spin precession in the double pulsar.

    PubMed

    Breton, Rene P; Kaspi, Victoria M; Kramer, Michael; McLaughlin, Maura A; Lyutikov, Maxim; Ransom, Scott M; Stairs, Ingrid H; Ferdman, Robert D; Camilo, Fernando; Possenti, Andrea

    2008-07-01

    The double pulsar PSR J0737-3039A/B consists of two neutron stars in a highly relativistic orbit that displays a roughly 30-second eclipse when pulsar A passes behind pulsar B. Describing this eclipse of pulsar A as due to absorption occurring in the magnetosphere of pulsar B, we successfully used a simple geometric model to characterize the observed changing eclipse morphology and to measure the relativistic precession of pulsar B's spin axis around the total orbital angular momentum. This provides a test of general relativity and alternative theories of gravity in the strong-field regime. Our measured relativistic spin precession rate of 4.77 degrees (-0 degrees .65)(+0 degrees .66) per year (68% confidence level) is consistent with that predicted by general relativity within an uncertainty of 13%. PMID:18599782

  16. Resistive Magnetohydrodynamic Simulations of Relativistic Magnetic Reconnection

    NASA Technical Reports Server (NTRS)

    Zenitani, Seiji; Hesse, Michael; Klimas, Alex

    2010-01-01

    Resistive relativistic magnetohydrodynamic (RRMHD) simulations are applied to investigate the system evolution of relativistic magnetic reconnection. A time-split Harten-Lan-van Leer method is employed. Under a localized resistivity, the system exhibits a fast reconnection jet with an Alfv enic Lorentz factor inside a narrow Petschek-type exhaust. Various shock structures are resolved in and around the plasmoid such as the post-plasmoid vertical shocks and the "diamond-chain" structure due to multiple shock reflections. Under a uniform resistivity, Sweet-Parker-type reconnection slowly evolves. Under a current-dependent resistivity, plasmoids are repeatedly formed in an elongated current sheet. It is concluded that the resistivity model is of critical importance for RRMHD modeling of relativistic magnetic reconnection.

  17. Relativistic electron acceleration by oblique whistler waves

    SciTech Connect

    Yoon, Peter H.; Pandey, Vinay S.; Lee, Dong-Hun

    2013-11-15

    Test-particle simulations of electrons interacting with finite-amplitude, obliquely propagating whistler waves are carried out in order to investigate the acceleration of relativistic electrons by these waves. According to the present findings, an efficient acceleration of relativistic electrons requires a narrow range of oblique propagation angles, close to the whistler resonance cone angle, when the wave amplitude is held constant at relatively low value. For a constant wave propagation angle, it is found that a range of oblique whistler wave amplitudes permits the acceleration of relativistic electrons to O(MeV) energies. An initial distribution of test electrons is shown to form a power-law distribution when plotted in energy space. It is also found that the acceleration is largely uniform in electron pitch-angle space.

  18. Relativistic mirrors in laser plasmas (analytical methods)

    NASA Astrophysics Data System (ADS)

    Bulanov, S. V.; Esirkepov, T. Zh; Kando, M.; Koga, J.

    2016-10-01

    Relativistic flying mirrors in plasmas are realized as thin dense electron (or electron-ion) layers accelerated by high-intensity electromagnetic waves to velocities close to the speed of light in vacuum. The reflection of an electromagnetic wave from the relativistic mirror results in its energy and frequency changing. In a counter-propagation configuration, the frequency of the reflected wave is multiplied by the factor proportional to the Lorentz factor squared. This scientific area promises the development of sources of ultrashort x-ray pulses in the attosecond range. The expected intensity will reach the level at which the effects predicted by nonlinear quantum electrodynamics start to play a key role. We present an overview of theoretical methods used to describe relativistic flying, accelerating, oscillating mirrors emerging in intense laser-plasma interactions.

  19. Relativistic dynamics, Green function and pseudodifferential operators

    NASA Astrophysics Data System (ADS)

    Cirilo-Lombardo, Diego Julio

    2016-06-01

    The central role played by pseudodifferential operators in relativistic dynamics is known very well. In this work, operators like the Schrodinger one (e.g., square root) are treated from the point of view of the non-local pseudodifferential Green functions. Starting from the explicit construction of the Green (semigroup) theoretical kernel, a theorem linking the integrability conditions and their dependence on the spacetime dimensions is given. Relativistic wave equations with arbitrary spin and the causality problem are discussed with the algebraic interpretation of the radical operator and their relation with coherent and squeezed states. Also we perform by means of pure theoretical procedures (based in physical concepts and symmetry) the relativistic position operator which satisfies the conditions of integrability: it is a non-local, Lorentz invariant and does not have the same problems as the "local"position operator proposed by Newton and Wigner. Physical examples, as zitterbewegung and rogue waves, are presented and deeply analyzed in this theoretical framework.

  20. GRASP: General-purpose Relativistic Atomic Structure Package

    NASA Astrophysics Data System (ADS)

    Grant, I. P.; McKenzie, B. J.; Norrington, P. H.; Mayers, D. F.; Pyper, N. C.

    2016-09-01

    GRASP (General-purpose Relativistic Atomic Structure Package) calculates atomic structure, including energy levels, radiative rates (A-values) and lifetimes; it is a fully relativistic code based on the jj coupling scheme.

  1. Relativistic momentum and kinetic energy, and E = mc2

    NASA Astrophysics Data System (ADS)

    Yu-Kuang Hu, Ben

    2009-03-01

    Based on relativistic velocity addition and the conservation of momentum and energy, I present simple derivations of the expressions for the relativistic momentum and kinetic energy of a particle, and for the formula E = mc2.

  2. The relativistic equations of stellar structure and evolution

    NASA Technical Reports Server (NTRS)

    Thorne, K. S.

    1977-01-01

    The general-relativistic equations of stellar structure and evolution are reformulated in a notation which makes easy contact with Newtonian theory. Also, a general-relativistic version of the mixing-length formalism for convection is presented.

  3. Inverse Problems of Thermoelectricity

    NASA Astrophysics Data System (ADS)

    Anatychuk, L. I.; Luste, O. J.; Kuz, R. V.; Strutinsky, M. N.

    2011-05-01

    Classical thermoelectricity is based on the use of the Seebeck and Thomson effects that occur in the near-contact areas between n- and p-type materials. A conceptually different approach to thermoelectric power converter design that is based on the law of thermoelectric induction of currents is also known. The efficiency of this approach has already been demonstrated by its first applications. More than 10 basically new types of thermoelements were discovered with properties that cannot be achieved by thermocouple power converters. Therefore, further development of this concept is of practical interest. This paper provides a classification and theory for solving the inverse problems of thermoelectricity that form the basis for devising new thermoelement types. Computer methods for their solution for anisotropic and inhomogeneous media are elaborated. Regularities related to thermoelectric current excitation in anisotropic and inhomogeneous media are established. The possibility of obtaining eddy currents of a particular configuration through control of the temperature field and material parameters for the creation of new thermo- element types is demonstrated for three-dimensional (3D) models of anisotropic and inhomogeneous media.

  4. Inverse problem in hydrogeology

    NASA Astrophysics Data System (ADS)

    Carrera, Jesús; Alcolea, Andrés; Medina, Agustín; Hidalgo, Juan; Slooten, Luit J.

    2005-03-01

    The state of the groundwater inverse problem is synthesized. Emphasis is placed on aquifer characterization, where modelers have to deal with conceptual model uncertainty (notably spatial and temporal variability), scale dependence, many types of unknown parameters (transmissivity, recharge, boundary conditions, etc.), nonlinearity, and often low sensitivity of state variables (typically heads and concentrations) to aquifer properties. Because of these difficulties, calibration cannot be separated from the modeling process, as it is sometimes done in other fields. Instead, it should be viewed as one step in the process of understanding aquifer behavior. In fact, it is shown that actual parameter estimation methods do not differ from each other in the essence, though they may differ in the computational details. It is argued that there is ample room for improvement in groundwater inversion: development of user-friendly codes, accommodation of variability through geostatistics, incorporation of geological information and different types of data (temperature, occurrence and concentration of isotopes, age, etc.), proper accounting of uncertainty, etc. Despite this, even with existing codes, automatic calibration facilitates enormously the task of modeling. Therefore, it is contended that its use should become standard practice. L'état du problème inverse des eaux souterraines est synthétisé. L'accent est placé sur la caractérisation de l'aquifère, où les modélisateurs doivent jouer avec l'incertitude des modèles conceptuels (notamment la variabilité spatiale et temporelle), les facteurs d'échelle, plusieurs inconnues sur différents paramètres (transmissivité, recharge, conditions aux limites, etc.), la non linéarité, et souvent la sensibilité de plusieurs variables d'état (charges hydrauliques, concentrations) des propriétés de l'aquifère. A cause de ces difficultés, le calibrage ne peut êtreséparé du processus de modélisation, comme c'est le

  5. Polarization of inverse plasmon scattering

    NASA Technical Reports Server (NTRS)

    Windsor, R. A.; Kellogg, P. J.

    1974-01-01

    The scattering of electrostatic plasma waves by a flux of ultrarelativistic electrons passing through a plasma gives rise to a radiation spectrum which is similar to a synchrotron radiation spectrum. This mechanism, first considered by Gailitis and Tsytovich, is analagous to inverse Compton scattering, and we have named it inverse plasmon scattering. For a power-law electron flux, both inverse plasmon scattering and synchrotron radiation have the same spectral index. In an attempt to distinguish between these mechanisms, we have calculated the polarization level expected from inverse plasmon scattering. The polarization level found is similar to that obtained from a synchrotron radiation source. This means that the radiation produced by two mechanisms, synchrotron radiation and inverse plasmon scattering, is indistinguishable; and this attempt to differentiate between them by polarization effects has been unsuccessful.

  6. Applying Relativistic Reconnection to Blazar Jets

    NASA Astrophysics Data System (ADS)

    Nalewajko, Krzysztof

    2016-09-01

    Rapid and luminous flares of non-thermal radiation observed in blazars require an efficient mechanism of energy dissipation and particle acceleration in relativistic active galactic nuclei (AGN) jets. Particle acceleration in relativistic magnetic reconnection is being actively studied by kinetic numerical simulations. Relativistic reconnection produces hard power-law electron energy distributions N(gamma) = N_0 gamma^(-p) exp(-gamma/gamma_max) with index p -> 1 and exponential cut-off Lorentz factor gamma_max ~ sigma in the limit of magnetization sigma = B^2/(4 pi w) >> 1 (where w is the relativistic enthalpy density). Reconnection in electron-proton plasma can additionally boost gamma_max by the mass ratio m_p/m_e. Hence, in order to accelerate particles to gamma_max ~ 10^6 in the case of BL Lacs, reconnection should proceed in plasma of very high magnetization sigma_max >~ 10^3. On the other hand, moderate mean jet magnetization values are required for magnetic bulk acceleration of relativistic jets, sigma_mean ~ Gamma_j <~ 20 (where Gamma_j is the jet bulk Lorentz factor). I propose that the systematic dependence of gamma_max on blazar luminosity class -- the blazar sequence -- may result from a systematic trend in sigma_max due to homogeneous loading of leptons by pair creation regulated by the energy density of high-energy external radiation fields. At the same time, relativistic AGN jets should be highly inhomogeneous due to filamentary loading of protons, which should determine the value of sigma_mean roughly independently of the blazar class.

  7. Restrictions imposed on relativistic two-body interactions by classical relativistic field theory

    NASA Astrophysics Data System (ADS)

    Crater, Horace W.; van Alstine, Peter

    1992-07-01

    We show that various relativistic potential models (all sharing exact relativistic two-body kinematics and a common nonrelativistic limit) can be distinguished by agreement or disagreement with relativistic corrections produced by classical field theory. We find that the only one of these models whose relativisic corrections duplicate those of classical field theory is the minimal Todorov equation. Conversely, we derive the Todorov equation from the semirelativistic dynamics of classical field theory, thus exposing the classical field-theoretic origins of its characteristic minimal potential structures and dependences on effective one-body variables.

  8. Alfven solitary waves in nonrelativistic, relativistic, and ultra-relativistic degenerate quantum plasma

    SciTech Connect

    Rehman, M. A.; Qureshi, M. N. S.; Shah, H. A.; Masood, W.

    2015-10-15

    Nonlinear circularly polarized Alfvén waves are studied in magnetized nonrelativistic, relativistic, and ultrarelativistic degenerate Fermi plasmas. Using the quantum hydrodynamic model, Zakharov equations are derived and the Sagdeev potential approach is used to investigate the properties of the electromagnetic solitary structures. It is seen that the amplitude increases with the increase of electron density in the relativistic and ultrarelativistic cases but decreases in the nonrelativistic case. Both right and left handed waves are considered, and it is seen that supersonic, subsonic, and super- and sub-Alfvénic solitary structures are obtained for different polarizations and under different relativistic regimes.

  9. Towards universal quantum computation through relativistic motion

    PubMed Central

    Bruschi, David Edward; Sabín, Carlos; Kok, Pieter; Johansson, Göran; Delsing, Per; Fuentes, Ivette

    2016-01-01

    We show how to use relativistic motion to generate continuous variable Gaussian cluster states within cavity modes. Our results can be demonstrated experimentally using superconducting circuits where tuneable boundary conditions correspond to mirrors moving with velocities close to the speed of light. In particular, we propose the generation of a quadripartite square cluster state as a first example that can be readily implemented in the laboratory. Since cluster states are universal resources for universal one-way quantum computation, our results pave the way for relativistic quantum computation schemes. PMID:26860584

  10. Relativistic Bohmian interpretation of quantum mechanics

    SciTech Connect

    Nikolic, Hrvoje

    2006-06-27

    I present a relativistic covariant version of the Bohmian interpretation of quantum mechanics and discuss the corresponding measurable predictions. The covariance is incoded in the fact that the nonlocal quantum potential transforms as a scalar, which is a consequence of the fact that the nonlocal wave function transforms as a scalar. The measurable predictions that can be obtained with the deterministic Bohmian interpretation cannot be obtained with the conventional interpretation simply because the conventional probabilistic interpretation does not work in the case of relativistic quantum mechanics.

  11. Electronic Broadening operator for relativistic plasmas

    SciTech Connect

    Meftah, M. T.; Naam, A.

    2008-10-22

    In this work we review some aspects of the semiclassical dipole impact approximation for isolated ion lines in relativistic plasma. Mainly we focuss our work on the collision operator for relativistic electrons. In this case, the electron trajectory around a positive charge in the plasma differs drastically from those known earlier as hyperbolic. The effect of this difference on the collision operator is discussed with respect the various plasma conditions. Some theoretical and practical aspects of lines -shape calculations are discussed. Detailed calculations are performed for the collision operator in the semiclassical (dipole) impact approximation.

  12. Relativistic Plasmas in Low Density Environments

    SciTech Connect

    Rudnick, Lawrence

    2009-12-18

    We have been developing techniques over the last several years to identify and study relativistic plasmas in low density environments. These relativistic plasmas may be the best or only available indicators of diffuse baryons in portions of the Warm-Hot Intergalactic Medium outside of rich galaxy clusters. Studying such faint radio synchrotron sources requires removal of confusion from both background radio galaxies and the foreground Milky Way. In these proceedings, we briefly summarize the techniques we are developing and some of our initial results. Our discoveries likely represent the ''tip of the iceberg'' to be exploited by the nascent generation of radio telescopes.

  13. Can Bohmian mechanics be made relativistic?

    PubMed Central

    Dürr, Detlef; Goldstein, Sheldon; Norsen, Travis; Struyve, Ward; Zanghì, Nino

    2014-01-01

    In relativistic space–time, Bohmian theories can be formulated by introducing a privileged foliation of space–time. The introduction of such a foliation—as extra absolute space–time structure—would seem to imply a clear violation of Lorentz invariance, and thus a conflict with fundamental relativity. Here, we consider the possibility that, instead of positing it as extra structure, the required foliation could be covariantly determined by the wave function. We argue that this allows for the formulation of Bohmian theories that seem to qualify as fundamentally Lorentz invariant. We conclude with some discussion of whether or not they might also qualify as fundamentally relativistic. PMID:24511259

  14. Can Bohmian mechanics be made relativistic?

    PubMed

    Dürr, Detlef; Goldstein, Sheldon; Norsen, Travis; Struyve, Ward; Zanghì, Nino

    2014-02-01

    In relativistic space-time, Bohmian theories can be formulated by introducing a privileged foliation of space-time. The introduction of such a foliation-as extra absolute space-time structure-would seem to imply a clear violation of Lorentz invariance, and thus a conflict with fundamental relativity. Here, we consider the possibility that, instead of positing it as extra structure, the required foliation could be covariantly determined by the wave function. We argue that this allows for the formulation of Bohmian theories that seem to qualify as fundamentally Lorentz invariant. We conclude with some discussion of whether or not they might also qualify as fundamentally relativistic. PMID:24511259

  15. Relativistic helix traveling wave tube amplifiers

    SciTech Connect

    Freund, H.P.; Vanderplaats, N.R.; Kodis, M.A. )

    1992-07-01

    A relativistic field theory of a helix traveling wave tube (TWT) is described for the case in which a thin annular beam propagates through a sheath helix enclosed within a loss-free wall. The theory is applied to the study of a TWT with an intense relativistic electron beam. The analysis implicitly includes beam space-charge effects and is valid for arbitrary azimuthal mode number, and the coupled-wave Pierce theory is recovered in the [ital near]-[ital resonant] limit. The results indicate that impressive gains and efficiencies are possible in this regime. In addition, the interaction is relatively insensitive to the effects of a beam energy spread.

  16. Recent progress in relativistic klystron research

    SciTech Connect

    Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Hoag, H.A.; Koontz, R.F.; Lavine, T.L.; Loew, G.A.; Miller, R.H.; Ruth, R.D.; Vlieks, A.E.; Wang, J.W.; Aalberts, D.P.; Boyd, J.K.; Houck, T.; Ryne, R.D.; Westenskow, G.A.; Yu, S.S.; Hopkins, D.B.; Sessler, A.M.; Haimson, J.; Mecklenburg, B.; Lawrence Livermore National Lab., CA (US

    1989-08-01

    Experimental work is now under way by collaborators at LLNL, SLAC, and LBL to investigate relativistic klystrons as a possible rf power source for future high-gradient accelerators. We have learned how to overcome our previously reported problem of high-power rf pulse shortening and have achieved peak rf power levels of 290 MW. We have used the rf from a relativistic klystron to power a short, 11.4-GHz high-gradient accelerator. The measured momentum spectrum of the accelerated electron beam corresponds to an accelerating gradient of 84 MV/m. 5 refs., 7 figs.

  17. Relativistic klystron research for high gradient accelerators

    SciTech Connect

    Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fowkes, W.R.; Herrmannsfeldt, W.B.; Higo, T.; Hoag, H.A.; Lavine, T.L.; Lee, T.G.

    1988-06-01

    Relativistic klystrons are being developed as a power source for high gradient accelerator applications which include large linear electron--positron colliders, compact accelerators, and FEL sources. We have attained 200MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. We report here on the design of our first klystrons, the results of our experiments so far, and some of our plans for the near future. 5 refs., 7 figs.

  18. Relativistic wave equations: an operational approach

    NASA Astrophysics Data System (ADS)

    Dattoli, G.; Sabia, E.; Górska, K.; Horzela, A.; Penson, K. A.

    2015-03-01

    The use of operator methods of an algebraic nature is shown to be a very powerful tool to deal with different forms of relativistic wave equations. The methods provide either exact or approximate solutions for various forms of differential equations, such as relativistic Schrödinger, Klein-Gordon, and Dirac. We discuss the free-particle hypotheses and those relevant to particles subject to non-trivial potentials. In the latter case we will show how the proposed method leads to easily implementable numerical algorithms.

  19. GENERAL RELATIVISTIC EFFECTS ON NONLINEAR POWER SPECTRA

    SciTech Connect

    Jeong, Donghui; Gong, Jinn-Ouk; Noh, Hyerim; Hwang, Jai-chan E-mail: jgong@lorentz.leidenuniv.nl E-mail: jchan@knu.ac.kr

    2011-01-20

    The nonlinear nature of Einstein's equation introduces genuine relativistic higher order corrections to the usual Newtonian fluid equations describing the evolution of cosmological perturbations. We study the effect of such novel nonlinearities on the next-to-leading order matter and velocity power spectra for the case of a pressureless, irrotational fluid in a flat Friedmann background. We find that pure general relativistic corrections are negligibly small over all scales. Our result guarantees that, in the current paradigm of standard cosmology, one can safely use Newtonian cosmology even in nonlinear regimes.

  20. Newtonian hydrodynamics with general relativistic pressure

    SciTech Connect

    Hwang, Jai-chan; Noh, Hyerim E-mail: hr@kasi.re.kr

    2013-10-01

    We present the general relativistic pressure correction terms in Newtonian hydrodynamic equations to the nonlinear order: these are equations (1.1)–(1.3). The derivation is made in the zero-shear gauge based on the fully nonlinear formulation of cosmological perturbation in Einstein's gravity. The correction terms differ from many of the previously suggested forms in the literature based on hand-waving manners. We confirm our results by comparing with (i) the nonlinear perturbation theory, (ii) the first order post-Newtonian approximation, and (iii) the special relativistic limit, and by checking (iv) the consistency with full Einstein's equation.