Sample records for modified general relativity

  1. Redshift and lateshift from homogeneous and isotropic modified dispersion relations

    NASA Astrophysics Data System (ADS)

    Pfeifer, Christian

    2018-05-01

    Observables which would indicate a modified vacuum dispersion relations, possibly caused by quantum gravity effects, are a four momentum dependence of the cosmological redshift and the existence of a so called lateshift effect for massless or very light particles. Existence or non-existence of the latter is currently analyzed on the basis of the available observational data from gamma-ray bursts and compared to predictions of specific modified dispersion relation models. We consider the most general perturbation of the general relativistic dispersion relation of freely falling particles on homogeneous and isotropic spacetimes and derive the red- and lateshift to first order in the perturbation. Our result generalizes the existing formulae in the literature and we find that there exist modified dispersion relations causing both, one or none of the two effects to first order.

  2. Correction of Cardy–Verlinde formula for Fermions and Bosons with modified dispersion relation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sadatian, S. Davood, E-mail: sd-sadatian@um.ac.ir; Dareyni, H.

    Cardy–Verlinde formula links the entropy of conformal symmetry field to the total energy and its Casimir energy in a D-dimensional space. To correct black hole thermodynamics, modified dispersion relation can be used which is proposed as a general feature of quantum gravity approaches. In this paper, the thermodynamics of Schwarzschild four-dimensional black hole is corrected using the modified dispersion relation for Fermions and Bosons. Finally, using modified thermodynamics of Schwarzschild four-dimensional black hole, generalization for Cardy–Verlinde formula is obtained. - Highlights: • The modified Cardy–Verlinde formula obtained using MDR for Fermions and Bosons. • The modified entropy of the blackmore » hole used to correct the Cardy–Verlinde formula. • The modified entropy of the CFT has been obtained.« less

  3. Performance of the modified Poisson regression approach for estimating relative risks from clustered prospective data.

    PubMed

    Yelland, Lisa N; Salter, Amy B; Ryan, Philip

    2011-10-15

    Modified Poisson regression, which combines a log Poisson regression model with robust variance estimation, is a useful alternative to log binomial regression for estimating relative risks. Previous studies have shown both analytically and by simulation that modified Poisson regression is appropriate for independent prospective data. This method is often applied to clustered prospective data, despite a lack of evidence to support its use in this setting. The purpose of this article is to evaluate the performance of the modified Poisson regression approach for estimating relative risks from clustered prospective data, by using generalized estimating equations to account for clustering. A simulation study is conducted to compare log binomial regression and modified Poisson regression for analyzing clustered data from intervention and observational studies. Both methods generally perform well in terms of bias, type I error, and coverage. Unlike log binomial regression, modified Poisson regression is not prone to convergence problems. The methods are contrasted by using example data sets from 2 large studies. The results presented in this article support the use of modified Poisson regression as an alternative to log binomial regression for analyzing clustered prospective data when clustering is taken into account by using generalized estimating equations.

  4. New insights on the matter-gravity coupling paradigm.

    PubMed

    Delsate, Térence; Steinhoff, Jan

    2012-07-13

    The coupling between matter and gravity in general relativity is given by a proportionality relation between the stress tensor and the geometry. This is an oriented assumption driven by the fact that both the stress tensor and the Einstein tensor are divergenceless. However, general relativity is in essence a nonlinear theory, so there is no obvious reason why the coupling to matter should be linear. On another hand, modified theories of gravity usually affect the vacuum dynamics, yet keep the coupling to matter linear. In this Letter, we address the implications of consistent nonlinear gravity-matter coupling. The Eddington-inspired Born-Infeld theory recently introduced by Bañados and Ferreira provides an enlightening realization of such coupling modifications. We find that this theory coupled to a perfect fluid reduces to general relativity coupled to a nonlinearly modified perfect fluid, leading to an ambiguity between modified coupling and modified equation of state. We discuss observational consequences of this degeneracy and argue that such a completion of general relativity is viable from both an experimental and theoretical point of view through energy conditions, consistency, and singularity-avoidance perspectives. We use these results to discuss the impact of changing the coupling paradigm.

  5. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Krasnov, Kirill; Shtanov, Yuri, E-mail: kirill.krasnov@nottingham.ac.uk, E-mail: shtanov@bitp.kiev.ua

    We study linear cosmological perturbations in a previously introduced family of deformations of general relativity characterized by the absence of new degrees of freedom. The homogeneous and isotropic background in this class of theories is unmodified and is described by the usual Friedmann equations. The theory of cosmological perturbations is modified and the relevant deformation parameter has the dimension of length. Gravitational perturbations of the scalar type can be described by a certain relativistic potential related to the matter perturbations just as in general relativity. A system of differential equations describing the evolution of this potential and of the stress-energymore » density perturbations is obtained. We find that the evolution of scalar perturbations proceeds with a modified effective time-dependent speed of sound, which, contrary to the case of general relativity, does not vanish even at the matter-dominated stage. In a broad range of values of the length parameter controlling the deformation, a specific transition from the regime of modified gravity to the regime of general relativity in the evolution of scalar perturbations takes place during the radiation domination. In this case, the resulting power spectrum of perturbations in radiation and dark matter is suppressed on the comoving spatial scales that enter the Hubble radius before this transition. We estimate the bounds on the deformation parameter for which this suppression does not lead to observable consequences. Evolution of scalar perturbations at the inflationary stage is modified but very slightly and the primordial spectrum generated during inflation is not noticeably different from the one obtained in general relativity.« less

  6. Modified rubisco large subunit n-methyltransferase useful for targeting molecules to the active-site vicinity of ribulose-1,5-bisphosphate

    DOEpatents

    Houtz, Robert L [Lexington, KY

    2012-03-20

    The present invention generally relates to a modified Rubisco large subunit .sup..epsilon.N-Methyltransferase (Rubisco LSMT, or RLSMT). The present invention also relates to a modified RLSMT-carbonic anhydrase (RLSMT-CA). This modified RLSMT-CA improves the efficiency of the reduction of CO.sub.2 during photosynthesis, which may increase plant growth rates. The present invention also relates to nucleic acids encoding the modified RLSMT-CA or modified RLSMT. Also, the present invention relates to cells including the modified RLSMT-CA or modified RLSMT, plants containing the modified RLSMT-CA or modified RLSMT, and methods using compositions of the present invention. In addition, the present invention relates to antibodies conjugated to CA which may bind to Rubisco, and antibodies which bind a modified RLSMT-CA. The invention also relates to modified forms of the LS and SS of Rubisco where the modified forms are fusions with CA or biologically active fragments thereof. The present invention provides methods of altering Rubisco carboxylase activity and altering plant growth.

  7. Generalized energy measurements and modified transient quantum fluctuation theorems

    NASA Astrophysics Data System (ADS)

    Watanabe, Gentaro; Venkatesh, B. Prasanna; Talkner, Peter

    2014-05-01

    Determining the work which is supplied to a system by an external agent provides a crucial step in any experimental realization of transient fluctuation relations. This, however, poses a problem for quantum systems, where the standard procedure requires the projective measurement of energy at the beginning and the end of the protocol. Unfortunately, projective measurements, which are preferable from the point of view of theory, seem to be difficult to implement experimentally. We demonstrate that, when using a particular type of generalized energy measurements, the resulting work statistics is simply related to that of projective measurements. This relation between the two work statistics entails the existence of modified transient fluctuation relations. The modifications are exclusively determined by the errors incurred in the generalized energy measurements. They are universal in the sense that they do not depend on the force protocol. Particularly simple expressions for the modified Crooks relation and Jarzynski equality are found for Gaussian energy measurements. These can be obtained by a sequence of sufficiently many generalized measurements which need not be Gaussian. In accordance with the central limit theorem, this leads to an effective error reduction in the individual measurements and even yields a projective measurement in the limit of infinite repetitions.

  8. FNF Construction, Inc. Coverage under General Air Quality Permit for New or Modified Minor Source Hot Mix Asphalt Plants in Indian Country

    EPA Pesticide Factsheets

    Documents related to the FNF Construction, Inc. Request for Coverage under the General Air Quality Permit for New or Modified Minor Source Hot Mix Asphalt Plants in Indian Country to be Located near Ganado, Arizona on the Navajo Nation.

  9. Testing general relativity with compact-body orbits: a modified Einstein–Infeld–Hoffmann framework

    NASA Astrophysics Data System (ADS)

    Will, Clifford M.

    2018-04-01

    We describe a general framework for analyzing orbits of systems containing compact objects (neutron stars or black holes) in a class of Lagrangian-based alternative theories of gravity that also admit a global preferred reference frame. The framework is based on a modified Einstein–Infeld–Hoffmann (EIH) formalism developed by Eardley and by Will, generalized to include the possibility of Lorentz-violating, preferred-frame effects. It uses a post-Newtonian N-body Lagrangian with arbitrary parameters that depend on the theory of gravity and on ‘sensitivities’ that encode the effects of the bodies’ internal structure on their motion. We determine the modified EIH parameters for the Einstein-Æther and Khronometric vector-tensor theories of gravity. We find the effects of motion relative to a preferred universal frame on the orbital parameters of binary systems containing neutron stars, such as a class of ultra-circular pulsar-white dwarf binaries; the amplitudes of the effects depend upon ‘strong-field’ preferred-frame parameters \\hatα1 and \\hatα2 , which we relate to the fundamental modified EIH parameters. We also determine the amplitude of the ‘Nordtvedt effect’ in a triple system containing the pulsar J0337+1715 in terms of the modified EIH parameters.

  10. The effect of finite Larmor radius corrections on Jeans instability of quantum plasma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sharma, Prerana; Chhajlani, R. K.

    2013-09-15

    The influence of finite Larmor radius (FLR) effects on the Jeans instability of infinitely conducting homogeneous quantum plasma is investigated. The quantum magnetohydrodynamic (QMHD) model is used to formulate the problem. The contribution of FLR is incorporated to the QMHD set of equations in the present analysis. The general dispersion relation is obtained analytically using the normal mode analysis technique which is modified due to the contribution of FLR corrections. From general dispersion relation, the condition of instability is obtained and it is found that Jeans condition is modified due to quantum effect. The general dispersion relation is reduced formore » both transverse and longitudinal mode of propagations. The condition of gravitational instability is modified due to the presence of both FLR and quantum corrections in the transverse mode of propagation. In longitudinal case, it is found to be unaffected by the FLR effects but modified due to the quantum corrections. The growth rate of Jeans instability is discussed numerically for various values of quantum and FLR corrections of the medium. It is found that the quantum parameter and FLR effects have stabilizing influence on the growth rate of instability of the system.« less

  11. Fisher Sand & Gravel New Mexico, Inc. General Air Quality Permit: Related Documents

    EPA Pesticide Factsheets

    Documents related to the Fisher Sand & Gravel – New Mexico, Inc., Grey Mesa Gravel Pit General Air Quality Permit for New or Modified Minor Source Stone Quarrying, Crushing, and Screening Facilities in Indian Country.

  12. General Relativity solutions in modified gravity

    NASA Astrophysics Data System (ADS)

    Motohashi, Hayato; Minamitsuji, Masato

    2018-06-01

    Recent gravitational wave observations of binary black hole mergers and a binary neutron star merger by LIGO and Virgo Collaborations associated with its optical counterpart constrain deviation from General Relativity (GR) both on strong-field regime and cosmological scales with high accuracy, and further strong constraints are expected by near-future observations. Thus, it is important to identify theories of modified gravity that intrinsically possess the same solutions as in GR among a huge number of theories. We clarify the three conditions for theories of modified gravity to allow GR solutions, i.e., solutions with the metric satisfying the Einstein equations in GR and the constant profile of the scalar fields. Our analysis is quite general, as it applies a wide class of single-/multi-field scalar-tensor theories of modified gravity in the presence of matter component, and any spacetime geometry including cosmological background as well as spacetime around black hole and neutron star, for the latter of which these conditions provide a necessary condition for no-hair theorem. The three conditions will be useful for further constraints on modified gravity theories as they classify general theories of modified gravity into three classes, each of which possesses i) unique GR solutions (i.e., no-hair cases), ii) only hairy solutions (except the cases that GR solutions are realized by cancellation between singular coupling functions in the Euler-Lagrange equations), and iii) both GR and hairy solutions, for the last of which one of the two solutions may be selected dynamically.

  13. Chern-Simons Modified Gravity

    NASA Astrophysics Data System (ADS)

    Efstratiou, P.

    2013-09-01

    This presentation will be based on my, undergraduate, thesis at Aristotle University of Thessoliniki with the same subject, supervised by Professor Demetrios Papadopoulos. I will first present the general mathematical formulation of the Chern-Simons (CS) modified gravity, which is split in a dynamical and a non-dynamical context, and the different physical theories which suggest this modification. Then proceed by examing the possibility that the CS theory shares solutions with General Relativity in both contexts. In the non-dynamical context I will present a new, undocumented solution as well as all the other possible solutions found to date. I will conclude by arguing that General Relativity and CS Theory share any solutions in the dynamical context.

  14. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Song, Yong-Seon; Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX; Zhao Gongbo

    We explore the complementarity of weak lensing and galaxy peculiar velocity measurements to better constrain modifications to General Relativity. We find no evidence for deviations from General Relativity on cosmological scales from a combination of peculiar velocity measurements (for Luminous Red Galaxies in the Sloan Digital Sky Survey) with weak lensing measurements (from the Canadian France Hawaii Telescope Legacy Survey). We provide a Fisher error forecast for a Euclid-like space-based survey including both lensing and peculiar velocity measurements and show that the expected constraints on modified gravity will be at least an order of magnitude better than with present data,more » i.e. we will obtain {approx_equal}5% errors on the modified gravity parametrization described here. We also present a model-independent method for constraining modified gravity parameters using tomographic peculiar velocity information, and apply this methodology to the present data set.« less

  15. Dark stars in Starobinsky's model

    NASA Astrophysics Data System (ADS)

    Panotopoulos, Grigoris; Lopes, Ilídio

    2018-01-01

    In the present work we study non-rotating dark stars in f (R ) modified theory of gravity. In particular, we have considered bosonic self-interacting dark matter modeled inside the star as a Bose-Einstein condensate, while as far as the modified theory of gravity is concerned we have assumed Starobinsky's model R +a R2. We solve the generalized structure equations numerically, and we obtain the mass-to-ratio relation for several different values of the parameter a , and for two different dark matter equation-of-states. Our results show that the dark matter stars become more compact in the R-squared gravity compared to general relativity, while at the same time the highest star mass is slightly increased in the modified gravitational theory. The numerical value of the highest star mass for each case has been reported.

  16. Confirmation of general relativity on large scales from weak lensing and galaxy velocities.

    PubMed

    Reyes, Reinabelle; Mandelbaum, Rachel; Seljak, Uros; Baldauf, Tobias; Gunn, James E; Lombriser, Lucas; Smith, Robert E

    2010-03-11

    Although general relativity underlies modern cosmology, its applicability on cosmological length scales has yet to be stringently tested. Such a test has recently been proposed, using a quantity, E(G), that combines measures of large-scale gravitational lensing, galaxy clustering and structure growth rate. The combination is insensitive to 'galaxy bias' (the difference between the clustering of visible galaxies and invisible dark matter) and is thus robust to the uncertainty in this parameter. Modified theories of gravity generally predict values of E(G) different from the general relativistic prediction because, in these theories, the 'gravitational slip' (the difference between the two potentials that describe perturbations in the gravitational metric) is non-zero, which leads to changes in the growth of structure and the strength of the gravitational lensing effect. Here we report that E(G) = 0.39 +/- 0.06 on length scales of tens of megaparsecs, in agreement with the general relativistic prediction of E(G) approximately 0.4. The measured value excludes a model within the tensor-vector-scalar gravity theory, which modifies both Newtonian and Einstein gravity. However, the relatively large uncertainty still permits models within f(R) theory, which is an extension of general relativity. A fivefold decrease in uncertainty is needed to rule out these models.

  17. Confirmation of general relativity on large scales from weak lensing and galaxy velocities

    NASA Astrophysics Data System (ADS)

    Reyes, Reinabelle; Mandelbaum, Rachel; Seljak, Uros; Baldauf, Tobias; Gunn, James E.; Lombriser, Lucas; Smith, Robert E.

    2010-03-01

    Although general relativity underlies modern cosmology, its applicability on cosmological length scales has yet to be stringently tested. Such a test has recently been proposed, using a quantity, EG, that combines measures of large-scale gravitational lensing, galaxy clustering and structure growth rate. The combination is insensitive to `galaxy bias' (the difference between the clustering of visible galaxies and invisible dark matter) and is thus robust to the uncertainty in this parameter. Modified theories of gravity generally predict values of EG different from the general relativistic prediction because, in these theories, the `gravitational slip' (the difference between the two potentials that describe perturbations in the gravitational metric) is non-zero, which leads to changes in the growth of structure and the strength of the gravitational lensing effect. Here we report that EG = 0.39+/-0.06 on length scales of tens of megaparsecs, in agreement with the general relativistic prediction of EG~0.4. The measured value excludes a model within the tensor-vector-scalar gravity theory, which modifies both Newtonian and Einstein gravity. However, the relatively large uncertainty still permits models within f() theory, which is an extension of general relativity. A fivefold decrease in uncertainty is needed to rule out these models.

  18. Cosmic Tsunamis in Modified Gravity: Disruption of Screening Mechanisms from Scalar Waves.

    PubMed

    Hagala, R; Llinares, C; Mota, D F

    2017-03-10

    Extending general relativity by adding extra degrees of freedom is a popular approach for explaining the accelerated expansion of the Universe and to build high energy completions of the theory of gravity. The presence of such new degrees of freedom is, however, tightly constrained from several observations and experiments that aim to test general relativity in a wide range of scales. The viability of a given modified theory of gravity, therefore, strongly depends on the existence of a screening mechanism that suppresses the extra degrees of freedom. We perform simulations, and find that waves propagating in the new degrees of freedom can significantly impact the efficiency of some screening mechanisms, thereby threatening the viability of these modified gravity theories. Specifically, we show that the waves produced in the symmetron model can increase the amplitude of the fifth force and the parametrized post Newtonian parameters by several orders of magnitude.

  19. Cosmic Tsunamis in Modified Gravity: Disruption of Screening Mechanisms from Scalar Waves

    NASA Astrophysics Data System (ADS)

    Hagala, R.; Llinares, C.; Mota, D. F.

    2017-03-01

    Extending general relativity by adding extra degrees of freedom is a popular approach for explaining the accelerated expansion of the Universe and to build high energy completions of the theory of gravity. The presence of such new degrees of freedom is, however, tightly constrained from several observations and experiments that aim to test general relativity in a wide range of scales. The viability of a given modified theory of gravity, therefore, strongly depends on the existence of a screening mechanism that suppresses the extra degrees of freedom. We perform simulations, and find that waves propagating in the new degrees of freedom can significantly impact the efficiency of some screening mechanisms, thereby threatening the viability of these modified gravity theories. Specifically, we show that the waves produced in the symmetron model can increase the amplitude of the fifth force and the parametrized post Newtonian parameters by several orders of magnitude.

  20. Quantifying cardiometabolic risk using modifiable non-self-reported risk factors.

    PubMed

    Marino, Miguel; Li, Yi; Pencina, Michael J; D'Agostino, Ralph B; Berkman, Lisa F; Buxton, Orfeu M

    2014-08-01

    Sensitive general cardiometabolic risk assessment tools of modifiable risk factors would be helpful and practical in a range of primary prevention interventions or for preventive health maintenance. To develop and validate a cumulative general cardiometabolic risk score that focuses on non-self-reported modifiable risk factors such as glycosylated hemoglobin (HbA1c) and BMI so as to be sensitive to small changes across a span of major modifiable risk factors, which may not individually cross clinical cut-off points for risk categories. We prospectively followed 2,359 cardiovascular disease (CVD)-free subjects from the Framingham offspring cohort over a 14-year follow-up. Baseline (fifth offspring examination cycle) included HbA1c and cholesterol measurements. Gender-specific Cox proportional hazards models were considered to evaluate the effects of non-self-reported modifiable risk factors (blood pressure, total cholesterol, high-density lipoprotein cholesterol, smoking, BMI, and HbA1c) on general CVD risk. We constructed 10-year general cardiometabolic risk score functions and evaluated its predictive performance in 2012-2013. HbA1c was significantly related to general CVD risk. The proposed cardiometabolic general CVD risk model showed good predictive performance as determined by cross-validated discrimination (male C-index=0.703, 95% CI=0.668, 0.734; female C-index=0.762, 95% CI=0.726, 0.801) and calibration (lack-of-fit chi-square=9.05 [p=0.338] and 12.54 [p=0.128] for men and women, respectively). This study presents a risk factor algorithm that provides a convenient and informative way to quantify cardiometabolic risk on the basis of modifiable risk factors that can motivate an individual's commitment to prevention and intervention. Copyright © 2014 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  1. Quantifying Cardiometabolic Risk Using Modifiable Non–Self-Reported Risk Factors

    PubMed Central

    Marino, Miguel; Li, Yi; Pencina, Michael J.; D’Agostino, Ralph B.; Berkman, Lisa F.; Buxton, Orfeu M.

    2014-01-01

    Background Sensitive general cardiometabolic risk assessment tools of modifiable risk factors would be helpful and practical in a range of primary prevention interventions or for preventive health maintenance. Purpose To develop and validate a cumulative general cardiometabolic risk score that focuses on non–self-reported modifiable risk factors such as glycosylated hemoglobin (HbA1c) and BMI so as to be sensitive to small changes across a span of major modifiable risk factors, which may not individually cross clinical cut off points for risk categories. Methods We prospectively followed 2,359 cardiovascular disease (CVD)-free subjects from the Framingham offspring cohort over a 14–year follow-up. Baseline (fifth offspring examination cycle) included HbA1c and cholesterol measurements. Gender–specific Cox proportional hazards models were considered to evaluate the effects of non–self-reported modifiable risk factors (blood pressure, total cholesterol, high–density lipoprotein cholesterol, smoking, BMI, and HbA1c) on general CVD risk. We constructed 10–year general cardiometabolic risk score functions and evaluated its predictive performance in 2012–2013. Results HbA1c was significantly related to general CVD risk. The proposed cardiometabolic general CVD risk model showed good predictive performance as determined by cross-validated discrimination (male C-index=0.703, 95% CI=0.668, 0.734; female C-index=0.762, 95% CI=0.726, 0.801) and calibration (lack-of-fit χ2=9.05 [p=0.338] and 12.54 [p=0.128] for men and women, respectively). Conclusions This study presents a risk factor algorithm that provides a convenient and informative way to quantify cardiometabolic risk based on modifiable risk factors that can motivate an individual’s commitment to prevention and intervention. PMID:24951039

  2. Dark Energy, or Worse

    ScienceCinema

    Carroll, Sean

    2018-01-09

    General relativity is inconsistent with cosmological observations unless we invoke components of dark matter and dark energy that dominate the universe. While it seems likely that these exotic substances really do exist, the alternative is worth considering: that Einstein's general relativity breaks down on cosmological scales. I will discuss models of modified gravity, tests in the solar system and elsewhere, and consequences for cosmology.

  3. General very special relativity in Finsler cosmology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kouretsis, A. P.; Stathakopoulos, M.; Stavrinos, P. C.

    2009-05-15

    General very special relativity (GVSR) is the curved space-time of very special relativity (VSR) proposed by Cohen and Glashow. The geometry of general very special relativity possesses a line element of Finsler geometry introduced by Bogoslovsky. We calculate the Einstein field equations and derive a modified Friedmann-Robertson-Walker cosmology for an osculating Riemannian space. The Friedmann equation of motion leads to an explanation of the cosmological acceleration in terms of an alternative non-Lorentz invariant theory. A first order approach for a primordial-spurionic vector field introduced into the metric gives back an estimation of the energy evolution and inflation.

  4. Nonlocal Gravity and Structure in the Universe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dodelson, Scott; Park, Sohyun

    2014-08-26

    The observed acceleration of the Universe can be explained by modifying general relativity. One such attempt is the nonlocal model of Deser and Woodard. Here we fix the background cosmology using results from the Planck satellite and examine the predictions of nonlocal gravity for the evolution of structure in the universe, confronting the model with three tests: gravitational lensing, redshift space distortions, and the estimator of gravitymore » $$E_G$$. Current data favor general relativity (GR) over nonlocal gravity: fixing primordial cosmology with the best fit parameters from Planck leads to weak lensing results favoring GR by 5.9 sigma; redshift space distortions measurements of the growth rate preferring GR by 7.8 sigma; and the single measurement of $$E_G$$ favoring GR, but by less than 1-sigma. The significance holds up even after the parameters are allowed to vary within Planck limits. The larger lesson is that a successful modified gravity model will likely have to suppress the growth of structure compared to general relativity.« less

  5. Nonlinear analysis of generalized cross-field current instability

    NASA Technical Reports Server (NTRS)

    Yoon, Peter H.; Lui, Anthony T. Y.

    1993-01-01

    Analysis of the generalized cross-field current instability is carried out in which cross-field drift of both the ions and electrons and their temperatures are permitted to vary in time. The unstable mode under consideration is the electromagnetic generalization of the classical modified-two-stream instability. The generalized instability is made of the modified-two-stream and ion-Weibel modes. The relative importance of the features associated with the ion-Weibel mode and those of the modified-two-stream mode is assessed. Specific applications are made to the Earth's neutral sheet prior to substorm onset and to the Earth's bow shock. The numerical solution indicates that the ion-Weibel mode dominates in the Earth's neutral sheet environment. In contrast, the situation for the bow shock is dominated by the modified-two-stream mode. Notable differences are found between the present calculation and previous results on ion-Weibel mode which restrict the analysis to only parallel propagating waves. However, in the case of Earth's bow shock for which the ion-Weibel mode plays no important role, the inclusion of the electromagnetic ion response is found to differ little from the previous results which treats ions responding only to the electrostatic component of the excited waves.

  6. Rainbows without unicorns: metric structures in theories with modified dispersion relations

    NASA Astrophysics Data System (ADS)

    Lobo, Iarley P.; Loret, Niccoló; Nettel, Francisco

    2017-07-01

    Rainbow metrics are a widely used approach to the metric formalism for theories with modified dispersion relations. They have had a huge success in the quantum gravity phenomenology literature, since they allow one to introduce momentum-dependent space-time metrics into the description of systems with a modified dispersion relation. In this paper, we introduce the reader to some realizations of this general idea: the original rainbow metrics proposal, the momentum-space-inspired metric and a Finsler geometry approach. As the main result of this work we also present an alternative definition of a four-velocity dependent metric which allows one to handle the massless limit. This paper aims to highlight some of their properties and how to properly describe their relativistic realizations.

  7. New classes of modified teleparallel gravity models

    NASA Astrophysics Data System (ADS)

    Bahamonde, Sebastian; Böhmer, Christian G.; Krššák, Martin

    2017-12-01

    New classes of modified teleparallel theories of gravity are introduced. The action of this theory is constructed to be a function of the irreducible parts of torsion f (Tax ,Tten ,Tvec), where Tax ,Tten and Tvec are squares of the axial, tensor and vector components of torsion, respectively. This is the most general (well-motivated) second order teleparallel theory of gravity that can be constructed from the torsion tensor. Different particular second order theories can be recovered from this theory such as new general relativity, conformal teleparallel gravity or f (T) gravity. Additionally, the boundary term B which connects the Ricci scalar with the torsion scalar via R = - T + B can also be incorporated into the action. By performing a conformal transformation, it is shown that the two unique theories which have an Einstein frame are either the teleparallel equivalent of general relativity or f (- T + B) = f (R) gravity, as expected.

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hearin, Andrew P.; Zentner, Andrew R., E-mail: aph15@pitt.edu, E-mail: zentner@pitt.edu

    Forthcoming projects such as the Dark Energy Survey, Joint Dark Energy Mission, and the Large Synoptic Survey Telescope, aim to measure weak lensing shear correlations with unprecedented accuracy. Weak lensing observables are sensitive to both the distance-redshift relation and the growth of structure in the Universe. If the cause of accelerated cosmic expansion is dark energy within general relativity, both cosmic distances and structure growth are governed by the properties of dark energy. Consequently, one may use lensing to check for this consistency and test general relativity. After reviewing the phenomenology of such tests, we address a major challenge tomore » such a program. The evolution of the baryonic component of the Universe is highly uncertain and can influence lensing observables, manifesting as modified structure growth for a fixed cosmic distance scale. Using two proposed methods, we show that one could be led to reject the null hypothesis of general relativity when it is the true theory if this uncertainty in baryonic processes is neglected. Recent simulations suggest that we can correct for baryonic effects using a parameterized model in which the halo mass-concentration relation is modified. The correction suffices to render biases small compared to statistical uncertainties. We study the ability of future weak lensing surveys to constrain the internal structures of halos and test the null hypothesis of general relativity simultaneously. Compared to alternative methods which null information from small-scales to mitigate sensitivity to baryonic physics, this internal calibration program should provide limits on deviations from general relativity that are several times more constraining. Specifically, we find that limits on general relativity in the case of internal calibration are degraded by only {approx} 30% or less compared to the case of perfect knowledge of nonlinear structure.« less

  9. General virial theorem for modified-gravity MOND

    NASA Astrophysics Data System (ADS)

    Milgrom, Mordehai

    2014-01-01

    An important and useful relation is known to hold in two specific MOND theories. It pertains to low-acceleration, isolated systems of pointlike masses, mp, at positions rp, subject to gravitational forces Fp. It reads ∑prp·Fp=-(2/3)(Ga0)1/2 [(∑pmp)3/2-∑p mp3/2]; a0 is the MOND acceleration constant. Here I show that this relation holds in the nonrelativistic limit of any modified-gravity MOND theory. It follows from only the basic tenets of MOND, which include departure from standard dynamics at accelerations below a0, and space-time scale invariance in the nonrelativistic, low-acceleration limit. This implies space-dilatation invariance of the static, gravitational-field equations, which, in turn, leads to the above point-mass virial relation. Thus, the various MOND predictions and tests based on this relation hold in any modified-gravity MOND theory. Since we do not know that any of the existing MOND theories point in the right direction, it is important to identify such predictions that hold in a much larger class of theories. Among these predictions are the MOND two-body force for arbitrary masses, and a general mass-velocity-dispersion relation of the form σ2=(2/3)(MGa0)1/2[1-∑p(mp/M)3/2], where M = ∑p mp.

  10. A Behavior Analytically Modified Implicit Association Test for Measuring Sexual Categorization of Children

    ERIC Educational Resources Information Center

    Gavin, Amanda; Roche, Bryan; Ruiz, Maria R.; Hogan, Maria; O'Reilly, Anthony

    2012-01-01

    The current study assessed the sexual categorization of children among a random sample of adults from the general population. Twenty-seven males and 27 females (N = 54) were exposed to a categorization task that assessed their ability to discriminate adult- from child-related words and sexual from non-sexual words. Then, in a modified Implicit…

  11. Effects of Hall current and electrical resistivity on the stability of gravitating anisotropic quantum plasma

    NASA Astrophysics Data System (ADS)

    Bhakta, S.; Prajapati, R. P.

    2018-02-01

    The effects of Hall current and finite electrical resistivity are studied on the stability of uniformly rotating and self-gravitating anisotropic quantum plasma. The generalized Ohm's law modified by Hall current and electrical resistivity is used along with the quantum magnetohydrodynamic fluid equations. The general dispersion relation is derived using normal mode analysis and discussed in the parallel and perpendicular propagations. In the parallel propagation, the Jeans instability criterion, expression of critical Jeans wavenumber, and Jeans length are found to be independent of non-ideal effects and uniform rotation but in perpendicular propagation only rotation affects the Jeans instability criterion. The unstable gravitating mode modified by Bohm potential and the stable Alfven mode modified by non-ideal effects are obtained separately. The criterion of firehose instability remains unaffected due to the presence of non-ideal effects. In the perpendicular propagation, finite electrical resistivity and quantum pressure anisotropy modify the dispersion relation, whereas no effect of Hall current was observed in the dispersion characteristics. The Hall current, finite electrical resistivity, rotation, and quantum corrections stabilize the growth rate. The stability of the dynamical system is analyzed using the Routh-Hurwitz criterion.

  12. Testing modified gravity with globular clusters: the case of NGC 2419

    NASA Astrophysics Data System (ADS)

    Llinares, Claudio

    2018-05-01

    The dynamics of globular clusters has been studied in great detail in the context of general relativity as well as with modifications of gravity that strongly depart from the standard paradigm such as Modified Newtonian Dynamics. However, at present there are no studies that aim to test the impact that less extreme modifications of gravity (e.g. models constructed as alternatives to dark energy) have on the behaviour of globular clusters. This Letter presents fits to the velocity dispersion profile of the cluster NGC 2419 under the symmetron-modified gravity model. The data show an increase in the velocity dispersion towards the centre of the cluster which could be difficult to explain within general relativity. By finding the best-fitting solution associated with the symmetron model, we show that this tension does not exist in modified gravity. However, the best-fitting parameters give a model that is inconsistent with the dynamics of the Solar system. Exploration of different screening mechanisms should give us the chance to understand if it is possible to maintain the appealing properties of the symmetron model when it comes to globular clusters and at the same time recover the Solar system dynamics properly.

  13. Equivalent off-diagonal cosmological models and ekpyrotic scenarios in -modified, massive, and einstein gravity

    NASA Astrophysics Data System (ADS)

    Vacaru, Sergiu I.

    2015-04-01

    We reinvestigate how generic off-diagonal cosmological solutions depending, in general, on all spacetime coordinates can be constructed in massive and -modified gravity using the anholonomic frame deformation method. New classes of locally anisotropic and (in-) homogeneous cosmological metrics are constructed with open and closed spatial geometries. By resorting to such solutions, we show that they describe the late time acceleration due to effective cosmological terms induced by nonlinear off-diagonal interactions, possible modifications of the gravitational action and graviton mass. The cosmological metrics and related Stückelberg fields are constructed in explicit form up to nonholonomic frame transforms of the Friedmann-Lamaître-Robertson-Walker (FLRW) coordinates. The solutions include matter, graviton mass, and other effective sources modeling nonlinear gravitational and matter field interactions with polarization of physical constants and deformations of metrics, which may explain dark energy and dark matter effects. However, we argue that it is not always necessary to modify gravity if we consider the effective generalized Einstein equations with nontrivial vacuum and/or non-minimal coupling with matter. Indeed, we state certain conditions when such configurations mimic interesting solutions in general relativity and modifications, for instance, when we can extract the general Painlevé-Gullstrand and FLRW metrics. In a more general context, we elaborate on a reconstruction procedure for off-diagonal cosmological solutions which describe cyclic and ekpyrotic universes. Finally, open issues and further perspectives are discussed.

  14. Axial quasinormal modes of static neutron stars in the nonminimal derivative coupling sector of Horndeski gravity: Spectrum and universal relations for realistic equations of state

    NASA Astrophysics Data System (ADS)

    Blázquez-Salcedo, Jose Luis; Eickhoff, Kevin

    2018-05-01

    We study axial quasinormal modes of static neutron stars in the nonminimal derivative coupling sector of Horndeski theory. We focus on the fundamental curvature mode, which we analyze for 10 different equations of state with different matter content. A comparison with the results obtained in pure general relativity reveals that, apart from modifying the spectrum of the frequencies and the damping times of the stars, this theory modifies several universal relations between the modes and physical parameters of the stars that are otherwise matter independent.

  15. Nonlinear effective theory of dark energy

    NASA Astrophysics Data System (ADS)

    Cusin, Giulia; Lewandowski, Matthew; Vernizzi, Filippo

    2018-04-01

    We develop an approach to parametrize cosmological perturbations beyond linear order for general dark energy and modified gravity models characterized by a single scalar degree of freedom. We derive the full nonlinear action, focusing on Horndeski theories. In the quasi-static, non-relativistic limit, there are a total of six independent relevant operators, three of which start at nonlinear order. The new nonlinear couplings modify, beyond linear order, the generalized Poisson equation relating the Newtonian potential to the matter density contrast. We derive this equation up to cubic order in perturbations and, in a companion article [1], we apply it to compute the one-loop matter power spectrum. Within this approach, we also discuss the Vainshtein regime around spherical sources and the relation between the Vainshtein scale and the nonlinear scale for structure formation.

  16. Effect of ten quaternary ammonium cations on tetrachloromethane sorption to clay from water

    USGS Publications Warehouse

    Smith, J.A.

    1990-01-01

    The mineral surface of Wyoming bentonite (clay) was modified by replacing inorganic ions by each of 10 quaternary ammonium compounds, and tetrachloromethane sorption to the modified sorbents from water was studied. Tetrachloromethane sorption from solution to clay modified with tetramethyl-, tetraethyl-, benzyltrimethyl-, or benzyltriethylammonium cations generally is characterized by relatively high solute uptake, isotherm nonlinearity, and competitive sorption (with trichloroethene as the competing sorbate). For these sorbents, the ethyl functional groups yield reduced sorptive capacity relative to methyl groups, whereas the benzyl group appears to have a similar effect on sorbent capacity as the methyl group. Sorption of tetrachloromethane to clay modified with dodecyldimethyl(2-phenoxyethyl)-, dodecyltrimethyl-, tetradecyltrimethyl-, hexadecyltrimethyl-, or benzyldimethylhexadecylammonium bromide is characterized by relatively low solute uptake, isotherm linearity, and noncompetitive sorption. For these sorbents, an increase in the size of the nonpolar functional group(s) causes an increase in the organic carbon normalized sorption coefficient (Koc). No measurable uptake of tetrachloromethane sorption by the unmodified clay or clay modified by ammonium bromide was observed. ?? 1990 American Chemical Society.

  17. S2 like Star Orbits near the Galactic Center in Rn and Yukawa Gravity

    NASA Astrophysics Data System (ADS)

    Borka, Dusko; Jovanović, Predrag; Jovanović Vesna Borka; Zakharov, Alexander F.

    2015-01-01

    In this chapter we investigate the possibility to provide theoretical explanation for the observed deviations of S2 star orbit around the Galactic Center using gravitational potentials derived from extended gravity models, but in absence of dark matter. Extended Theories of Gravity are alternative theories of gravitational interaction developed from the exact starting points investigated first by Einstein and Hilbert and aimed from one side to extend the positive results of General Relativity and, on the other hand, to cure its shortcomings. One of the aims of these theories is to explain galactic and extragalactic dynamics without introduction of dark matter. They are based on straightforward generalizations of the Einstein theory where the gravitational action (the Hilbert-Einstein action) is assumed to be linear in the Ricci curvature scalar R. The f(R) gravity is a type of modified gravity which generalizes Einstein's General Relativity, i.e. the simplest case is just the General Relativity. It is actually a family of models, each one defined by a different function of the Ricci scalar. Here, we consider Rn (power-law fourth-order theories of gravity) and Yukawa-like modified gravities in the weak field limit and discuss the constrains on these theories. For that purpose we simulate the orbit of S2 star around the Galactic Center in Rn and Yukawa-like gravity potentials and compare it with New Technology Telescope/Very Large Telescope (NTT/VLT) as well as by Keck telescope observations. Our simulations result in strong constraints on the range of gravity interaction and showed that both Rn and Yukawa gravity could satisfactorily explain the observed orbits of S2 star. However, we concluded that parameters of Rn and Yukawa gravity theories must be very close to those corresponding to the Newtonian limit of the theory. Besides, in contrast to Newtonian gravity, these two modified theories induce orbital precession, even in the case of point-like central mass. The approach we are proposing seems to be sufficiently reliable to constrain the modified gravity models from stellar orbits around Galactic Center.

  18. Constraining modified gravitational theories by weak lensing with Euclid

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Martinelli, Matteo; Calabrese, Erminia; De Bernardis, Francesco

    2011-01-15

    Future proposed satellite missions such as Euclid can offer the opportunity to test general relativity on cosmic scales through mapping of the galaxy weak-lensing signal. In this paper we forecast the ability of these experiments to constrain modified gravity scenarios such as those predicted by scalar-tensor and f(R) theories. We find that Euclid will improve constraints expected from the Planck satellite on these modified theories of gravity by 2 orders of magnitude. We discuss parameter degeneracies and the possible biases introduced by modifications to gravity.

  19. Teleparallel equivalent of Lovelock gravity

    NASA Astrophysics Data System (ADS)

    González, P. A.; Vásquez, Yerko

    2015-12-01

    There is a growing interest in modified gravity theories based on torsion, as these theories exhibit interesting cosmological implications. In this work inspired by the teleparallel formulation of general relativity, we present its extension to Lovelock gravity known as the most natural extension of general relativity in higher-dimensional space-times. First, we review the teleparallel equivalent of general relativity and Gauss-Bonnet gravity, and then we construct the teleparallel equivalent of Lovelock gravity. In order to achieve this goal, we use the vielbein and the connection without imposing the Weitzenböck connection. Then, we extract the teleparallel formulation of the theory by setting the curvature to null.

  20. Sex and gender differences in the causes of dementia: a narrative review.

    PubMed

    Rocca, Walter A; Mielke, Michelle M; Vemuri, Prashanthi; Miller, Virginia M

    2014-10-01

    This is a narrative review of new ideas and concepts related to differences between men and women in their risk of developing dementia or Alzheimer's disease (AD). We introduce the concept of dimorphic neurology and the distinction between sex and gender. We then provide three examples of risk factors related to sex and gender from the literature. Apolipoprotein E genotype is equally common in men and women but has a stronger effect in women. Apolipoprotein E genotype is a biological factor that cannot be modified but interacts with sex or gender related factors that can be modified. Low education has a similar harmful effect in men and women but has been historically more common in women. Education is a social factor related to gender that can be modified. Finally, bilateral oophorectomy is a factor restricted to women. Bilateral oophorectomy is a surgical practice related to sex that can be modified. Consideration of risk and protective factors in men and women separately may accelerate etiologic research for neurological diseases in general, and for dementia and AD in particular. Similarly, future preventive interventions for dementia should be tailored to men and women separately. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Operant Conditioning and Learning: Examples, Sources, Technology.

    ERIC Educational Resources Information Center

    Pedrini, Bonnie C.; Pedrini, D. T.

    The purpose of this paper is to relate psychology to teaching generally, and to relate behavior shaping to curriculum, specifically. Focusing on operant conditioning and learning, many studies are cited which illustrate some of the work being done toward effectively shaping or modifying student behavior whether in terms of subject matter or…

  2. Does food store access modify associations between intrapersonal factors and fruit and vegetable consumption?

    PubMed

    Thornton, L E; Lamb, K E; Tseng, M; Crawford, D A; Ball, K

    2015-08-01

    Existing theoretical frameworks suggest that healthy eating is facilitated by an individual's ability, motivation and environmental opportunities. It is plausible, although largely untested, that the importance of factors related to ability and motivation differ under varied environmental conditions. This study aimed to determine whether the magnitude of associations between fruit and vegetable consumption and intrapersonal factors (ability and motivation) were modified by differences in access to stores selling these items (environmental opportunities). Cross-sectional analysis of 4335 women from socioeconomically disadvantaged neighbourhoods in the state of Victoria, Australia. Self-reported fruit and vegetable consumption was assessed against a number of ability- and motivation-related factors. To examine whether associations were modified by store access, interactions with access to supermarkets and greengrocers within 2 km of participants' households were tested. Of the two factors related to ability and seven factors related to motivation, almost all were associated with fruit and vegetable consumption. In general, associations were not modified by store access suggesting that these factors were not tempered by environmental opportunities. This study provides little support for the hypothesis that the importance of intra-personal factors to fruit and vegetable consumption is modified by food store access. Further research on this topic is required to inform behaviour change interventions.

  3. COLA with scale-dependent growth: applications to screened modified gravity models

    NASA Astrophysics Data System (ADS)

    Winther, Hans A.; Koyama, Kazuya; Manera, Marc; Wright, Bill S.; Zhao, Gong-Bo

    2017-08-01

    We present a general parallelized and easy-to-use code to perform numerical simulations of structure formation using the COLA (COmoving Lagrangian Acceleration) method for cosmological models that exhibit scale-dependent growth at the level of first and second order Lagrangian perturbation theory. For modified gravity theories we also include screening using a fast approximate method that covers all the main examples of screening mechanisms in the literature. We test the code by comparing it to full simulations of two popular modified gravity models, namely f(R) gravity and nDGP, and find good agreement in the modified gravity boost-factors relative to ΛCDM even when using a fairly small number of COLA time steps.

  4. Palatini wormholes and energy conditions from the prism of general relativity.

    PubMed

    Bejarano, Cecilia; Lobo, Francisco S N; Olmo, Gonzalo J; Rubiera-Garcia, Diego

    2017-01-01

    Wormholes are hypothetical shortcuts in spacetime that in general relativity unavoidably violate all of the pointwise energy conditions. In this paper, we consider several wormhole spacetimes that, as opposed to the standard designer procedure frequently employed in the literature, arise directly from gravitational actions including additional terms resulting from contractions of the Ricci tensor with the metric, and which are formulated assuming independence between metric and connection (Palatini approach). We reinterpret such wormhole solutions under the prism of General Relativity and study the matter sources that thread them. We discuss the size of violation of the energy conditions in different cases and how this is related to the same spacetimes when viewed from the modified gravity side.

  5. Estimation of global radiation for Sri Lanka

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Samuel, T.D.M.A.

    1991-01-01

    There are several formulae that relate global radiation to other climatological parameters such as sunshine hours, relative humidity, maximum temperature, and average temperature. In this paper a generally accepted modified form of the formula first introduced by Angstrom is used. It relates global radiation to hours of sunshine that have been measured for several years in many of the meteorological stations in Sri Lanka. The annual average of the ratio of the hours of sunshine to the length of the day, i.e., annual average of (S/Z), is found to vary considerably and to lie in the range 0.42-0.66. Fre're etmore » al., have found, using data from many parts of the world, a general graphical representation for the variation of a and b with annual average (S/Z) lying in the range 0.28 to 0.75. This variation of a and b can be expressed as quadratic functions are modified and used to determine a and b values for stations in Sri Lanka.« less

  6. Is Cosmic Acceleration Telling Us Something About Gravity?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Trodden, Mark

    2006-03-02

    Among the possible explanations for the observed acceleration of the universe, perhaps the boldest is the idea that new gravitational physics might be the culprit. In this colloquium I will discuss some of the challenges of constructing a sensible phenomenological extension of General Relativity, give examples of some candidate models of modified gravity and survey existing observational constraints on this approach. I will conclude by discussing how we might hope to distinguish between modifications of General Relativity and dark energy as competing hypotheses to explain cosmic acceleration.

  7. Is Cosmic Acceleration Telling Us Something About Gravity?

    ScienceCinema

    Trodden, Mark

    2018-05-11

    Among the possible explanations for the observed acceleration of the universe, perhaps the boldest is the idea that new gravitational physics might be the culprit. In this colloquium I will discuss some of the challenges of constructing a sensible phenomenological extension of General Relativity, give examples of some candidate models of modified gravity and survey existing observational constraints on this approach. I will conclude by discussing how we might hope to distinguish between modifications of General Relativity and dark energy as competing hypotheses to explain cosmic acceleration.

  8. Relativistic stars in vector-tensor theories

    NASA Astrophysics Data System (ADS)

    Kase, Ryotaro; Minamitsuji, Masato; Tsujikawa, Shinji

    2018-04-01

    We study relativistic star solutions in second-order generalized Proca theories characterized by a U (1 )-breaking vector field with derivative couplings. In the models with cubic and quartic derivative coupling, the mass and radius of stars become larger than those in general relativity for negative derivative coupling constants. This phenomenon is mostly attributed to the increase of star radius induced by a slower decrease of the matter pressure compared to general relativity. There is a tendency that the relativistic star with a smaller mass is not gravitationally bound for a low central density and hence is dynamically unstable, but that with a larger mass is gravitationally bound. On the other hand, we show that the intrinsic vector-mode couplings give rise to general relativistic solutions with a trivial field profile, so the mass and radius are not modified from those in general relativity.

  9. New Probe of Departures from General Relativity Using Minkowski Functionals.

    PubMed

    Fang, Wenjuan; Li, Baojiu; Zhao, Gong-Bo

    2017-05-05

    The morphological properties of the large scale structure of the Universe can be fully described by four Minkowski functionals (MFs), which provide important complementary information to other statistical observables such as the widely used 2-point statistics in configuration and Fourier spaces. In this work, for the first time, we present the differences in the morphology of the large scale structure caused by modifications to general relativity (to address the cosmic acceleration problem), by measuring the MFs from N-body simulations of modified gravity and general relativity. We find strong statistical power when using the MFs to constrain modified theories of gravity: with a galaxy survey that has survey volume ∼0.125(h^{-1}  Gpc)^{3} and galaxy number density ∼1/(h^{-1}  Mpc)^{3}, the two normal-branch Dvali-Gabadadze-Porrati models and the F5 f(R) model that we simulated can be discriminated from the ΛCDM model at a significance level ≳5σ with an individual MF measurement. Therefore, the MF of the large scale structure is potentially a powerful probe of gravity, and its application to real data deserves active exploration.

  10. A modified Lorentz theory as a test theory of special relativity

    NASA Technical Reports Server (NTRS)

    Chang, T.; Torr, D. G.; Gagnon, D. R.

    1988-01-01

    Attention has been given recently to a modified Lorentz theory (MLT) that is based on the generalized Galilean transformation. Some explicit formulas within the framework of MLT, dealing with the one-way velocity of light, slow-clock transport, and the Doppler effect are derived. A number of typical experiments are analyzed on this basis. Results indicate that the empirical equivalence between MLT and special relativity is still maintained to second order terms. The results of previous works that predict that the MLT might be distinguished from special relativity at the third order by Doppler centrifuge tests capable of a fractional frequency detection threshold of 10 to the -15th are confirmed.

  11. New Class of Quasinormal Modes of Neutron Stars in Scalar-Tensor Gravity

    NASA Astrophysics Data System (ADS)

    Mendes, Raissa F. P.; Ortiz, Néstor

    2018-05-01

    Detection of the characteristic spectrum of pulsating neutron stars can be a powerful tool not only to probe the nuclear equation of state but also to test modifications to general relativity. However, the shift in the oscillation spectrum induced by modified theories of gravity is often small and degenerate with our ignorance of the equation of state. In this Letter, we show that the coupling to additional degrees of freedom present in modified theories of gravity can give rise to new families of modes, with no counterpart in general relativity, which could be sufficiently well resolved in frequency space to allow for clear detection. We present a realization of this idea by performing a thorough study of radial oscillations of neutron stars in massless scalar-tensor theories of gravity. We anticipate astrophysical scenarios where the presence of this class of quasinormal modes could be probed with electromagnetic and gravitational wave measurements.

  12. General self-efficacy and the effect of hospital workplace violence on doctors' stress and job satisfaction in China.

    PubMed

    Yao, Yongcheng; Wang, Wei; Wang, Faxuan; Yao, Wu

    2014-06-01

    This study aims at exploring associations of general self-efficacy (GSE), workplace violence and doctors' work-related attitudes. In this study a cross-sectional survey design was applied. Questionnaires were administrated to 758 doctors working in 9 hospitals of Zhengzhou, Henan province, China, between June and October 2010. General information on age, gender, and years of working was collected, and the doctors' experience and witnessing workplace violence, job satisfaction, job initiative, occupational stress as well as GSE were measured. General linear regression analysis was performed in association analyses. Both experiencing and witnessing workplace violence were significantly positively correlated with the level of occupational stress but significantly negatively correlated with job satisfaction, job initiative, and GSE. General self-efficacy significantly modified relationships between both experiencing and witnessing workplace violence with occupational stress (β = 0.49 for experiencing violence; β = 0.43 for witnessing violence; p < 0.001) and with job satisfaction (β = -0.35 and -0.34, respectively; p < 0.05). However, it did not modify the relationships between both experiencing and witnessing workplace violence with job initiative (p > 0.05). The levels of occupational stress declined significantly with the increase of GSE, while job satisfaction increased significantly along with its increase. The effects of GSE on occupational stress and job satisfaction weakened as the frequency of violence increased. The findings suggest that GSE can modify effects of workplace violence on health care workers' stress and job satisfaction. Enhancing GSE in combination with stress reduction may lead to facilitating health care workers' recovery from workplace violence, and thereby improving their work-related attitudes.

  13. Probing hybrid modified gravity by stellar motion around Galactic Center

    NASA Astrophysics Data System (ADS)

    Borka, D.; Capozziello, S.; Jovanović, P.; Borka Jovanović, V.

    2016-06-01

    We consider possible signatures for the so called hybrid gravity within the Galactic Central Parsec. This modified theory of gravity consists of a superposition of the metric Einstein-Hilbert Lagrangian with an f(R) term constructed à la Palatiniand can be easily reduced to an equivalent scalar-tensor theory. Such an approach is introduced in order to cure the shortcomings related to f(R) gravity, in general formulated either in metric or in metric-affine frameworks. Hybrid gravity allows to disentangle the further gravitational degrees of freedom with respect to those of standard General Relativity. The present analysis is based on the S2 star orbital precession around the massive compact dark object at the Galactic Center where the simulated orbits in hybrid modified gravity are compared with astronomical observations. These simulations result with constraints on the range of hybrid gravity interaction parameter ϕ0, showing that in the case of S2 star it is between -0.0009 and -0.0002. At the same time, we are also able to obtain the constraints on the effective mass parameter mϕ, and found that it is between -0.0034 and -0.0025 AU-1 for S2 star. Furthermore, the hybrid gravity potential induces precession of S2 star orbit in the same direction as General Relativity. In previous papers, we considered other types of extended gravities, like metric power law f(R)∝Rn gravity, inducing Yukawa and Sanders-like gravitational potentials, but it seems that hybrid gravity is the best among these models to explain different gravitational phenomena at different astronomical scales.

  14. f(T) gravity and energy distribution in Landau-Lifshitz prescription

    NASA Astrophysics Data System (ADS)

    Ganiou, M. G.; Houndjo, M. J. S.; Tossa, J.

    We investigate in this paper the Landau-Lifshitz energy distribution in the framework of f(T) theory view as a modified version of Teleparallel theory. From some important Teleparallel theory results on the localization of energy, our investigations generalize the Landau-Lifshitz prescription from the computation of the energy-momentum complex to the framework of f(T) gravity as it is done in the modified versions of General Relativity. We compute the energy density in the first step for three plane-symmetric metrics in vacuum. We find for the second metric that the energy density vanishes independently of f(T) models. We find that the Teleparallel Landau-Lifshitz energy-momentum complex formulations for these metrics are different from those obtained in General Relativity for the same metrics. Second, the calculations are performed for the cosmic string spacetime metric. It results that the energy distribution depends on the mass M and the radius r of cosmic string and it is strongly affected by the parameter of the considered quadratic and cubic f(T) models. Our investigation with this metric induces interesting results susceptible to be tested with some astrophysics hypothesis.

  15. Unified cosmic history in modified gravity: From F(R) theory to Lorentz non-invariant models

    NASA Astrophysics Data System (ADS)

    Nojiri, Shin'Ichi; Odintsov, Sergei D.

    2011-08-01

    The classical generalization of general relativity is considered as the gravitational alternative for a unified description of the early-time inflation with late-time cosmic acceleration. The structure and cosmological properties of a number of modified theories, including traditional F(R) and Hořava-Lifshitz F(R) gravity, scalar-tensor theory, string-inspired and Gauss-Bonnet theory, non-local gravity, non-minimally coupled models, and power-counting renormalizable covariant gravity are discussed. Different representations of and relations between such theories are investigated. It is shown that some versions of the above theories may be consistent with local tests and may provide a qualitatively reasonable unified description of inflation with the dark energy epoch. The cosmological reconstruction of different modified gravities is provided in great detail. It is demonstrated that eventually any given universe evolution may be reconstructed for the theories under consideration, and the explicit reconstruction is applied to an accelerating spatially flat Friedmann-Robertson-Walker (FRW) universe. Special attention is paid to Lagrange multiplier constrained and conventional F(R) gravities, for latter F(R) theory, the effective ΛCDM era and phantom divide crossing acceleration are obtained. The occurrences of the Big Rip and other finite-time future singularities in modified gravity are reviewed along with their solutions via the addition of higher-derivative gravitational invariants.

  16. Canonical structure of general relativity with a limiting curvature and its relation to loop quantum gravity

    NASA Astrophysics Data System (ADS)

    Bodendorfer, N.; Schäfer, A.; Schliemann, J.

    2018-04-01

    Chamseddine and Mukhanov recently proposed a modified version of general relativity that implements the idea of a limiting curvature. In the spatially flat, homogeneous, and isotropic sector, their theory turns out to agree with the effective dynamics of the simplest version of loop quantum gravity if one identifies their limiting curvature with a multiple of the Planck curvature. At the same time, it extends to full general relativity without any symmetry assumptions and thus provides an ideal toy model for full loop quantum gravity in the form of a generally covariant effective action known to all orders. In this paper, we study the canonical structure of this theory and point out some interesting lessons for loop quantum gravity. We also highlight in detail how the two theories are connected in the spatially flat, homogeneous, and isotropic sector.

  17. Modeling Population and Ecosystem Response to Sublethal Toxicant Exposure

    DTIC Science & Technology

    2001-09-30

    mutualism utilized modified Lotka - Volterra (L-V) competition equations in which the sign of the interspecific interaction term was changed from...within complex communities and ecosystems. Prior to the current award, the PIs formulated and tested general dynamic energy budget models...Nisbet, 1998; chapter 7) make a convincing case that ecosystems do truly have dynamics that can be described by relatively simple, general , models

  18. Moments of inertia of relativistic magnetized stars

    NASA Astrophysics Data System (ADS)

    Konno, K.

    2001-06-01

    We consider principal moments of inertia of axisymmetric, magnetically deformed stars in the context of general relativity. The general expression for the moment of inertia with respect to the symmetric axis is obtained. The numerical estimates are derived for several polytropic stellar models. We find that the values of the principal moments of inertia are modified by a factor of 2 at most from Newtonian estimates.

  19. Non-singular and cyclic universe from the modified GUP

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Salah, Maha; Hammad, Fayçal; Faizal, Mir

    In this paper, we investigate the effects of a new version of the generalized uncertainty principle (modified GUP) on the dynamics of the Universe. As the modified GUP will modify the relation between the entropy and area of the apparent horizon, it will also deform the Friedmann equations within Jacobson's approach. We explicitly find these deformed Friedmann equations governing the modified GUP-corrected dynamics of such a Universe. It is shown that the modified GUP-deformed Jacobson's approach implies an upper bound for the density of such a Universe. The Big Bang singularity can therefore also be avoided using the modified GUP-correctionsmore » to horizons' thermodynamics. In fact, we are able to analyze the pre Big Bang state of the Universe. Furthermore, the equations imply that the expansion of the Universe will come to a halt and then will immediately be followed by a contracting phase. When the equations are extrapolated beyond the maximum rate of contraction, a cyclic Universe scenario emerges.« less

  20. Non-singular and cyclic universe from the modified GUP

    NASA Astrophysics Data System (ADS)

    Salah, Maha; Hammad, Fayçal; Faizal, Mir; Farag Ali, Ahmed

    2017-02-01

    In this paper, we investigate the effects of a new version of the generalized uncertainty principle (modified GUP) on the dynamics of the Universe. As the modified GUP will modify the relation between the entropy and area of the apparent horizon, it will also deform the Friedmann equations within Jacobson's approach. We explicitly find these deformed Friedmann equations governing the modified GUP-corrected dynamics of such a Universe. It is shown that the modified GUP-deformed Jacobson's approach implies an upper bound for the density of such a Universe. The Big Bang singularity can therefore also be avoided using the modified GUP-corrections to horizons' thermodynamics. In fact, we are able to analyze the pre Big Bang state of the Universe. Furthermore, the equations imply that the expansion of the Universe will come to a halt and then will immediately be followed by a contracting phase. When the equations are extrapolated beyond the maximum rate of contraction, a cyclic Universe scenario emerges.

  1. Testing for genetic association taking into account phenotypic information of relatives.

    PubMed

    Uh, Hae-Won; Wijk, Henk Jan van der; Houwing-Duistermaat, Jeanine J

    2009-12-15

    We investigated efficient case-control association analysis using family data. The outcome of interest was coronary heart disease. We employed existing and new methods that take into account the correlations among related individuals to obtain the proper type I error rates. The methods considered for autosomal single-nucleotide polymorphisms were: 1) generalized estimating equations-based methods, 2) variance-modified Cochran-Armitage (MCA) trend test incorporating kinship coefficients, and 3) genotypic modified quasi-likelihood score test. Additionally, for X-linked single-nucleotide polymorphisms we proposed a two-degrees-of-freedom test. Performance of these methods was tested using Framingham Heart Study 500 k array data.

  2. Giant pulsar glitches in full general relativity

    NASA Astrophysics Data System (ADS)

    Sourie, A.; Chamel, N.; Novak, J.; Oertel, M.

    2017-12-01

    We present recent numerical simulations of giant pulsar glitches, as observed in the emblematic Vela pulsar, based on a two-fluid model, including for the first time all general-relativistic effects and realistic equations of state. In particular, we focus on modelling the vortex-mediated transfer of angular momentum that takes place during the spin-up stage from the neutron superfluid to the charged particles through dissipative mutual friction forces. Taking general relativity into account does not only modify the structure of the star but also leads to a new coupling between the fluids arising from frame-dragging effects. As a consequence, general relativity can strongly affect the global dynamics of pulsar glitches : the errors on the value of the characteristic rise time incurred by using Newtonian gravity are thus found to be as large as ˜ 40 % for the models considered.

  3. Estimating ice particle scattering properties using a modified Rayleigh-Gans approximation

    NASA Astrophysics Data System (ADS)

    Lu, Yinghui; Clothiaux, Eugene E.; Aydin, Kültegin; Verlinde, Johannes

    2014-09-01

    A modification to the Rayleigh-Gans approximation is made that includes self-interactions between different parts of an ice crystal, which both improves the accuracy of the Rayleigh-Gans approximation and extends its applicability to polarization-dependent parameters. This modified Rayleigh-Gans approximation is both efficient and reasonably accurate for particles with at least one dimension much smaller than the wavelength (e.g., dendrites at millimeter or longer wavelengths) or particles with sparse structures (e.g., low-density aggregates). Relative to the Generalized Multiparticle Mie method, backscattering reflectivities at horizontal transmit and receive polarization (HH) (ZHH) computed with this modified Rayleigh-Gans approach are about 3 dB more accurate than with the traditional Rayleigh-Gans approximation. For realistic particle size distributions and pristine ice crystals the modified Rayleigh-Gans approach agrees with the Generalized Multiparticle Mie method to within 0.5 dB for ZHH whereas for the polarimetric radar observables differential reflectivity (ZDR) and specific differential phase (KDP) agreement is generally within 0.7 dB and 13%, respectively. Compared to the A-DDA code, the modified Rayleigh-Gans approximation is several to tens of times faster if scattering properties for different incident angles and particle orientations are calculated. These accuracies and computational efficiencies are sufficient to make this modified Rayleigh-Gans approach a viable alternative to the Rayleigh-Gans approximation in some applications such as millimeter to centimeter wavelength radars and to other methods that assume simpler, less accurate shapes for ice crystals. This method should not be used on materials with dielectric properties much different from ice and on compact particles much larger than the wavelength.

  4. Fixing extensions to general relativity in the nonlinear regime

    NASA Astrophysics Data System (ADS)

    Cayuso, Juan; Ortiz, Néstor; Lehner, Luis

    2017-10-01

    The question of what gravitational theory could supersede General Relativity has been central in theoretical physics for decades. Many disparate alternatives have been proposed motivated by cosmology, quantum gravity and phenomenological angles, and have been subjected to tests derived from cosmological, solar system and pulsar observations typically restricted to linearized regimes. Gravitational waves from compact binaries provide new opportunities to probe these theories in the strongly gravitating/highly dynamical regimes. To this end however, a reliable understanding of the dynamics in such a regime is required. Unfortunately, most of these theories fail to define well posed initial value problems, which prevents at face value from meeting such challenge. In this work, we introduce a consistent program able to remedy this situation. This program is inspired in the approach to "fixing" viscous relativistic hydrodynamics introduced by Israel and Stewart in the late 70's. We illustrate how to implement this approach to control undesirable effects of higher order derivatives in gravity theories and argue how the modified system still captures the true dynamics of the putative underlying theories in 3 +1 dimensions. We sketch the implementation of this idea in a couple of effective theories of gravity, one in the context of Noncommutative Geometry, and one in the context of Chern-Simons modified General Relativity.

  5. Experimental study on mean overtopping of sloping seawall under oblique irregular waves

    NASA Astrophysics Data System (ADS)

    Wang, Deng-ting; Ju, Lie-hong; Zhu, Jia-ling; Wang, Zhen; Sun, Tian-ting; Chen, Wei-qiu

    2017-06-01

    In this paper, domestic and abroad research progresses and related calculation formulae of the mean overtopping discharge are summarized. Through integral physical model experiments, the relation between the wave direction and the overtopping discharge on the top of the sloping dike is focused on and put into analysis and discussion; and a modified formula for mean overtopping discharges under oblique irregular waves is proposed. The study shows that the mean overtopping discharge generally goes down as the relative wave obliquity β increases for a fixed measurement point and the mean overtopping discharge generally increases as the wave steepness H/L decreases (the cycle increases) for a fixed relative wave obliquity.

  6. Owner attitudes and self reported behavior towards modified work after occupational injury absence in small enterprises: a qualitative study.

    PubMed

    Andersen, Lars Peter; Kines, Pete; Hasle, Peter

    2007-03-01

    Opportunities for modified work after an occupational injury are thought to be limited in small enterprises. This paper explores owner attitudes and self reported behavior towards modified work after injury-absence in small enterprises. Twenty-two owners of small construction and metal-processing enterprises were interviewed. Opportunities for modified work were possible in spite of some owners' general objections. Owners found their own solutions here-and-now without help from external stakeholders, and had little knowledge of possibilities for financial or practical support for early return-to-work initiatives. Initiatives formalizing modified work must be arranged in a way that supports the close social relations in small enterprises. Information to support the return to work process must be given when it is needed, i.e. at the onset of the prospect of lengthy work absence. The actual form of modified work should mainly be left up to the employer and the injured worker.

  7. Testing Modified Gravity Theories via Wide Binaries and GAIA

    NASA Astrophysics Data System (ADS)

    Pittordis, Charalambos; Sutherland, Will

    2018-06-01

    The standard ΛCDM model based on General Relativity (GR) including cold dark matter (CDM) is very successful at fitting cosmological observations, but recent non-detections of candidate dark matter (DM) particles mean that various modified-gravity theories remain of significant interest. The latter generally involve modifications to GR below a critical acceleration scale ˜10-10 m s-2. Wide-binary (WB) star systems with separations ≳ 5 kAU provide an interesting test for modified gravity, due to being in or near the low-acceleration regime and presumably containing negligible DM. Here, we explore the prospects for new observations pending from the GAIA spacecraft to provide tests of GR against MOND or TeVes-like theories in a regime only partially explored to date. In particular, we find that a histogram of (3D) binary relative velocities, relative to equilibrium circular velocity predicted from the (2D) projected separation predicts a rather sharp feature in this distribution for standard gravity, with an 80th (90th) percentile value close to 1.025 (1.14) with rather weak dependence on the eccentricity distribution. However, MOND/TeVeS theories produce a shifted distribution, with a significant increase in these upper percentiles. In MOND-like theories without an external field effect, there are large shifts of order unity. With the external field effect included, the shifts are considerably reduced to ˜0.04 - 0.08, but are still potentially detectable statistically given reasonably large samples and good control of contaminants. In principle, followup of GAIA-selected wide binaries with ground-based radial velocities accurate to ≲ 0.03 { km s^{-1}} should be able to produce an interesting new constraint on modified-gravity theories.

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Winther, Hans A.; Koyama, Kazuya; Wright, Bill S.

    We present a general parallelized and easy-to-use code to perform numerical simulations of structure formation using the COLA (COmoving Lagrangian Acceleration) method for cosmological models that exhibit scale-dependent growth at the level of first and second order Lagrangian perturbation theory. For modified gravity theories we also include screening using a fast approximate method that covers all the main examples of screening mechanisms in the literature. We test the code by comparing it to full simulations of two popular modified gravity models, namely f ( R ) gravity and nDGP, and find good agreement in the modified gravity boost-factors relative tomore » ΛCDM even when using a fairly small number of COLA time steps.« less

  9. Modified transverse phonon-helicon interaction in colloids laden semiconductor plasmas due to Bohm potential and Fermi degenerate pressure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sharma, Aartee, E-mail: aartee.sharma08@gmail.com; Yadav, N.; Ghosh, S.

    2015-07-31

    A detailed study of the quantum modification of acousto-helicon wave spectra due to Bohm potential and Fermi degenerate pressure in colloids laden semiconductor plasma has been presented. We have used quantum hydrodynamic model of plasmas to arrive at most general dispersion relation in presence of magnetic field. This dispersion relation has been analyzed in three different velocity regimes and the expressions for gain constants have been obtained. From the present study it has been concluded that the quantum effect and the magnetic field significantly modify the wave characteristics particularly in high doping regime in semiconductor plasma medium in presence ofmore » colloids in it.« less

  10. 46 CFR 53.12-1 - General (modifies HG-600 through HG-640).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false General (modifies HG-600 through HG-640). 53.12-1 Section 53.12-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING HEATING BOILERS Instruments, Fittings, and Controls (Article 6) § 53.12-1 General (modifies HG-600 through HG-640). (a) The instruments, fittings and...

  11. 46 CFR 52.15-1 - General (modifies PWT-1 through PWT-15).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false General (modifies PWT-1 through PWT-15). 52.15-1 Section 52.15-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Watertube Boilers § 52.15-1 General (modifies PWT-1 through PWT-15). Watertube boilers and parts thereof shall be as...

  12. 46 CFR 52.15-1 - General (modifies PWT-1 through PWT-15).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false General (modifies PWT-1 through PWT-15). 52.15-1 Section 52.15-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Watertube Boilers § 52.15-1 General (modifies PWT-1 through PWT-15). Watertube boilers and parts thereof shall be as...

  13. 46 CFR 52.15-1 - General (modifies PWT-1 through PWT-15).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false General (modifies PWT-1 through PWT-15). 52.15-1 Section 52.15-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Watertube Boilers § 52.15-1 General (modifies PWT-1 through PWT-15). Watertube boilers and parts thereof shall be as...

  14. 46 CFR 52.15-1 - General (modifies PWT-1 through PWT-15).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false General (modifies PWT-1 through PWT-15). 52.15-1 Section 52.15-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Watertube Boilers § 52.15-1 General (modifies PWT-1 through PWT-15). Watertube boilers and parts thereof shall be as...

  15. 46 CFR 53.12-1 - General (modifies HG-600 through HG-640).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false General (modifies HG-600 through HG-640). 53.12-1 Section 53.12-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING HEATING BOILERS Instruments, Fittings, and Controls (Article 6) § 53.12-1 General (modifies HG-600 through HG-640). (a) The instruments, fittings and...

  16. 46 CFR 53.12-1 - General (modifies HG-600 through HG-640).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false General (modifies HG-600 through HG-640). 53.12-1 Section 53.12-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING HEATING BOILERS Instruments, Fittings, and Controls (Article 6) § 53.12-1 General (modifies HG-600 through HG-640). (a) The instruments, fittings and...

  17. 46 CFR 53.12-1 - General (modifies HG-600 through HG-640).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false General (modifies HG-600 through HG-640). 53.12-1 Section 53.12-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING HEATING BOILERS Instruments, Fittings, and Controls (Article 6) § 53.12-1 General (modifies HG-600 through HG-640). (a) The instruments, fittings and...

  18. 46 CFR 53.12-1 - General (modifies HG-600 through HG-640).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false General (modifies HG-600 through HG-640). 53.12-1 Section 53.12-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING HEATING BOILERS Instruments, Fittings, and Controls (Article 6) § 53.12-1 General (modifies HG-600 through HG-640). (a) The instruments, fittings and...

  19. 46 CFR 52.15-1 - General (modifies PWT-1 through PWT-15).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false General (modifies PWT-1 through PWT-15). 52.15-1 Section 52.15-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Watertube Boilers § 52.15-1 General (modifies PWT-1 through PWT-15). Watertube boilers and parts thereof shall be as...

  20. A survey of general practitioners' views on autopsy reports.

    PubMed Central

    Karunaratne, S; Benbow, E W

    1997-01-01

    AIMS: To study the views of general practitioners on the quality and utility of autopsy reports, and on autopsies in general. METHODS: For a period of six months, a questionnaire was enclosed with each autopsy report sent to a general practitioner from the mortuary at Manchester Royal Infirmary. RESULTS: Most (93.3%) general practitioners found the autopsy report useful, and many (66.7%) thought the bereaved relatives would do so too. However, only a minority (25.2%) would discuss the report with the relatives. A considerable proportion (20.0%) found the cause of death surprising, and a significant number (10.4%) felt the report would modify their future clinical practice. There was approval of autopsies in general, with most (88.6%) agreeing that autopsies reveal lesions not detected in life, and many (74.4%) indicating that loss of the autopsy would impair severely the monitoring of clinical standards. CONCLUSIONS: General practitioners appreciate autopsy reports, which may have a significant impact on clinical practice. Autopsy reports provide both case audit and information for relatives. PMID:9306932

  1. Quasinormal modes as a distinguisher between general relativity and f (R ) gravity

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Soham; Shankaranarayanan, S.

    2017-09-01

    Quasinormal modes (QNMs) or the ringdown phase of gravitational waves provide critical information about the structure of compact objects like black holes. Thus, QNMs can be a tool to test general relativity (GR) and possible deviations from it. In the case of GR, it has been known for a long time that a relation between two types of black hole perturbations—scalar (Zerilli) and vector (Regge-Wheeler)—leads to an equal share of emitted gravitational energy. With the direct detection of gravitational waves, it is now natural to ask whether the same relation (between scalar and vector perturbations) holds for modified gravity theories, and if not, whether one can use this as a way to probe deviations from general relativity. As a first step, we show explicitly that the above relation between Regge-Wheeler and Zerilli perturbations breaks down for a general f (R ) model and hence the two perturbations do not share equal amounts of emitted gravitational energy. We discuss the implication of this imbalance for observations and the no-hair conjecture.

  2. Integrable multi-component generalization of a modified short pulse equation

    NASA Astrophysics Data System (ADS)

    Matsuno, Yoshimasa

    2016-11-01

    We propose a multi-component generalization of the modified short pulse (SP) equation which was derived recently as a reduction of Feng's two-component SP equation. Above all, we address the two-component system in depth. We obtain the Lax pair, an infinite number of conservation laws and multisoliton solutions for the system, demonstrating its integrability. Subsequently, we show that the two-component system exhibits cusp solitons and breathers for which the detailed analysis is performed. Specifically, we explore the interaction process of two cusp solitons and derive the formula for the phase shift. While cusp solitons are singular solutions, smooth breather solutions are shown to exist, provided that the parameters characterizing the solutions satisfy certain conditions. Last, we discuss the relation between the proposed system and existing two-component SP equations.

  3. PREFACE: X Mexican School on Gravitation and Mathematical Physics: ''Reaching a Century: Classical and Modified General Relativity's Attempts to explain de evolution of the Universe''

    NASA Astrophysics Data System (ADS)

    Bárcenas, R. B.; Hernández, H. H. H.; Sabido, M.

    2015-11-01

    The collection of papers in this volume was presented during the X Mexican School on Gravitation and Mathematical Physics, which was held in Playa del Carmen, Quintana Roo, México, December 1-5, 2014. The Mexican School on Gravitation and Mathematical Physics is a series of conferences sponsored by the Mexican Physical Society that started in 1994 with the purposes of discussing and exchanging current ideas in gravitational physics. Each Mexican School has been devoted to a particular subject, and these have included supergravity, branes, black holes, the early Universe, observational cosmology, quantum gravity and numerical relativity. In this ocasion the theme of the school was Reaching a Century: Classical and Modified General Relativity's Attempts to explain the evolution of the Universe, which focused on the discussion of classical and modified aspects of general relativity. Following our previous Schools, world leaders in the field were invited to give courses and plenary lectures. More specialized talks were also presented in parallel sessions, and some of them have been included in these proceedings. The contributions in this volume have been reviewed and represent some of the courses, plenary talks and contributed talks presented during our X School. We are indebted to the contributors of these proceedings as well as to the rest of the participants in our Mexican School all for making of it a complete success. As for financial support we should mention the Mexican National Science and Technology Council (CONACyT), the Royal Society of London (UK), the Mexican Physical Society (SMF), as well as several Institutions including: Centro de Investigación y Estudios Avanzados (CINVESTAV), Universidad Autónoma Metropolitana Iztapalapa (UAM-I), Universidad de Guanajuato (UG), and Universidad Nacional Autónoma de México (UNAM).

  4. Separating Dark Physics from Physical Darkness: Minimalist Modified Gravity vs. Dark Energy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huterer, Dragan; Linder, Eric V.

    The acceleration of the cosmic expansion may be due to a new component of physical energy density or a modification of physics itself. Mapping the expansion of cosmic scales and the growth of large scale structure in tandem can provide insights to distinguish between the two origins. Using Minimal Modified Gravity (MMG) - a single parameter gravitational growth index formalism to parameterize modified gravity theories - we examine the constraints that cosmological data can place on the nature of the new physics. For next generation measurements combining weak lensing, supernovae distances, and the cosmic microwave background we can extend themore » reach of physics to allow for fitting gravity simultaneously with the expansion equation of state, diluting the equation of state estimation by less than 25percent relative to when general relativity is assumed, and determining the growth index to 8percent. For weak lensing we examine the level of understanding needed of quasi- and nonlinear structure formation in modified gravity theories, and the trade off between stronger precision but greater susceptibility to bias as progressively more nonlinear information is used.« less

  5. Separating dark physics from physical darkness: Minimalist modified gravity versus dark energy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huterer, Dragan; Linder, Eric V.

    The acceleration of the cosmic expansion may be due to a new component of physical energy density or a modification of physics itself. Mapping the expansion of cosmic scales and the growth of large scale structure in tandem can provide insights to distinguish between the two origins. Using Minimal Modified Gravity (MMG) - a single parameter gravitational growth index formalism to parametrize modified gravity theories - we examine the constraints that cosmological data can place on the nature of the new physics. For next generation measurements combining weak lensing, supernovae distances, and the cosmic microwave background we can extend themore » reach of physics to allow for fitting gravity simultaneously with the expansion equation of state, diluting the equation of state estimation by less than 25% relative to when general relativity is assumed, and determining the growth index to 8%. For weak lensing we examine the level of understanding needed of quasi- and nonlinear structure formation in modified gravity theories, and the trade off between stronger precision but greater susceptibility to bias as progressively more nonlinear information is used.« less

  6. Analysis of Jeans instability of optically thick quantum plasma under the effect of modified Ohms law

    NASA Astrophysics Data System (ADS)

    Pensia, R. K.; Sutar, D. L.; Sharma, S.

    2018-05-01

    The Jeans instability of self-gravitating optically thick quantum plasma is reanalyzed in the framework of viscosity, black body radiation and modify ohms law. The usual magnetohydrodynamic (MHD) equation is used for the present configuration with black body radiation, viscosity, electrical resistivity and quantum corrections. A general dispersion relation is obtained with the help of linearized perturbation equations. It is found that the quantum correction has stabilizing effect on the system. The instability of system is discussed for various cases as our interest.

  7. 46 CFR 52.20-1 - General (modifies PFT-1 through PFT-49).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false General (modifies PFT-1 through PFT-49). 52.20-1 Section 52.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Firetube Boilers § 52.20-1 General (modifies PFT-1 through PFT-49). Firetube boilers and parts thereof shall be as indicated...

  8. 46 CFR 52.20-1 - General (modifies PFT-1 through PFT-49).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false General (modifies PFT-1 through PFT-49). 52.20-1 Section 52.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Firetube Boilers § 52.20-1 General (modifies PFT-1 through PFT-49). Firetube boilers and parts thereof shall be as indicated...

  9. 46 CFR 52.20-1 - General (modifies PFT-1 through PFT-49).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false General (modifies PFT-1 through PFT-49). 52.20-1 Section 52.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Firetube Boilers § 52.20-1 General (modifies PFT-1 through PFT-49). Firetube boilers and parts thereof shall be as indicated...

  10. 46 CFR 52.20-1 - General (modifies PFT-1 through PFT-49).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false General (modifies PFT-1 through PFT-49). 52.20-1 Section 52.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Firetube Boilers § 52.20-1 General (modifies PFT-1 through PFT-49). Firetube boilers and parts thereof shall be as indicated...

  11. 46 CFR 52.20-1 - General (modifies PFT-1 through PFT-49).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false General (modifies PFT-1 through PFT-49). 52.20-1 Section 52.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Firetube Boilers § 52.20-1 General (modifies PFT-1 through PFT-49). Firetube boilers and parts thereof shall be as indicated...

  12. Systematic Desensitization as a Method of Teaching a General Anxiety-Reducing Skill

    ERIC Educational Resources Information Center

    Zemore, Robert

    1975-01-01

    College students were treated with either a standard or modified version of systematic desensitization. Relative to a no-treatment control group, both treatment methods produced significant reductions in both the treated and untreated fears. The implications these findings have for two alternative conceptions of systematic desensitization are…

  13. 76 FR 61070 - Disaster Assistance; Hazard Mitigation Grant Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... systems from the list of eligible project types; and modified language relating to general, allowable open... types of projects. The project-type listing is not all-inclusive. FEMA published a Notice of Proposed... mitigation project types can be difficult to show using FEMA's conventional benefit/cost calculation...

  14. Teaching Personal Finance Mathematical Problem Solving to Individuals with Moderate Intellectual Disability

    ERIC Educational Resources Information Center

    Root, Jenny; Saunders, Alicia; Spooner, Fred; Brosh, Chelsi

    2017-01-01

    The ability to solve mathematical problems related to purchasing and personal finance is important in promoting skill generalization and increasing independence for individuals with moderate intellectual disabilities (IDs). Using a multiple probe across participant design, this study investigated the effects of modified schema-based instruction…

  15. 75 FR 38905 - To Modify Duty-Free Treatment Under the Generalized System of Preferences

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-06

    ... Part III The President Proclamation 8539--To Modify Duty-Free Treatment Under the Generalized... Duty-Free Treatment Under the Generalized System of Preferences By the President of the United States... eligible for preferential tariff treatment under the Generalized System of Preferences (GSP). 2. Pursuant...

  16. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gomes, C.; Bertolami, O.; Rosa, J.G., E-mail: claudio.gomes@fc.up.pt, E-mail: joao.rosa@ua.pt, E-mail: orfeu.bertolami@fc.up.pt

    We study inflationary scenarios driven by a scalar field in the presence of a non-minimal coupling between matter and curvature. We show that the Friedmann equation can be significantly modified when the energy density during inflation exceeds a critical value determined by the non-minimal coupling, which in turn may considerably modify the spectrum of primordial perturbations and the inflationary dynamics. In particular, we show that these models are characterised by a consistency relation between the tensor-to-scalar ratio and the tensor spectral index that can differ significantly from the predictions of general relativity. We also give examples of observational predictions formore » some of the most commonly considered potentials and use the results of the Planck collaboration to set limits on the scale of the non-minimal coupling.« less

  17. Clinical factors related to schizophrenia relapse.

    PubMed

    Porcelli, Stefano; Bianchini, Oriana; De Girolamo, Giovanni; Aguglia, Eugenio; Crea, Luciana; Serretti, Alessandro

    2016-01-01

    Relapses represent one of the main problems of schizophrenia management. This article reviews the clinical factors associated with schizophrenia relapse. A research of the last 22 years of literature data was performed. Two-hundred nineteen studies have been included. Three main groups of factors are related to relapse: factors associated with pharmacological treatment, add-on psychotherapeutic treatments and general risk factors. Overall, the absence of a maintenance therapy and treatment with first generation antipsychotics has been associated with higher risk of relapse. Further, psychotherapy add-on, particularly with cognitive behaviour therapy and psycho-education for both patients and relatives, has shown a good efficacy for reducing the relapse rate. Among general risk factors, some could be modified, such as the duration of untreated psychosis or the substance misuse, while others could not be modified as male gender or low pre-morbid level of functioning. Several classes of risk factors have been proved to be relevant in the risk of relapse. Thus, a careful assessment of the risk factors here identified should be performed in daily clinical practice in order to individualise the relapse risk for each patient and to provide a targeted treatment in high-risk subjects.

  18. [Safety assessment of foods derived from genetically modified plants].

    PubMed

    Pöting, A; Schauzu, M

    2010-06-01

    The placing of genetically modified plants and derived food on the market falls under Regulation (EC) No. 1829/2003. According to this regulation, applicants need to perform a safety assessment according to the Guidance Document of the Scientific Panel on Genetically Modified Organisms of the European Food Safety Authority (EFSA), which is based on internationally agreed recommendations. This article gives an overview of the underlying legislation as well as the strategy and scientific criteria for the safety assessment, which should generally be based on the concept of substantial equivalence and carried out in relation to an unmodified conventional counterpart. Besides the intended genetic modification, potential unintended changes also have to be assessed with regard to potential adverse effects for the consumer. All genetically modified plants and derived food products, which have been evaluated by EFSA so far, were considered to be as safe as products derived from the respective conventional plants.

  19. Searching for modified growth patterns with tomographic surveys

    NASA Astrophysics Data System (ADS)

    Zhao, Gong-Bo; Pogosian, Levon; Silvestri, Alessandra; Zylberberg, Joel

    2009-04-01

    In alternative theories of gravity, designed to produce cosmic acceleration at the current epoch, the growth of large scale structure can be modified. We study the potential of upcoming and future tomographic surveys such as Dark Energy Survey (DES) and Large Synoptic Survey Telescope (LSST), with the aid of cosmic microwave background (CMB) and supernovae data, to detect departures from the growth of cosmic structure expected within general relativity. We employ parametric forms to quantify the potential time- and scale-dependent variation of the effective gravitational constant and the differences between the two Newtonian potentials. We then apply the Fisher matrix technique to forecast the errors on the modified growth parameters from galaxy clustering, weak lensing, CMB, and their cross correlations across multiple photometric redshift bins. We find that even with conservative assumptions about the data, DES will produce nontrivial constraints on modified growth and that LSST will do significantly better.

  20. The mass-zero spin-two field and gravitational theory.

    NASA Technical Reports Server (NTRS)

    Coulter, C. A.

    1972-01-01

    Demonstration that the conventional theory of the mass-zero spin-two field with sources introduces extraneous nonspin-two field components in source regions and fails to be covariant under the full or restricted conformal group. A modified theory is given, expressed in terms of the physical components of mass-zero spin-two field rather than in terms of 'potentials,' which has no extraneous components inside or outside sources, and which is covariant under the full conformal group. For a proper choice of source term, this modified theory has the correct Newtonian limit and automatically implies that a symmetric second-rank source tensor has zero divergence. It is shown that possibly a generally covariant form of the spin-two theory derived here can be constructed to agree with general relativity in all currently accessible experimental situations.

  1. A parametrisation of modified gravity on nonlinear cosmological scales

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lombriser, Lucas, E-mail: llo@roe.ac.uk

    2016-11-01

    Viable modifications of gravity on cosmological scales predominantly rely on screening mechanisms to recover Einstein's Theory of General Relativity in the Solar System, where it has been well tested. A parametrisation of the effects of such modifications in the spherical collapse model is presented here for the use of modelling the modified nonlinear cosmological structure. The formalism allows an embedding of the different screening mechanisms operating in scalar-tensor theories through large values of the gravitational potential or its first or second derivatives as well as of linear suppression effects or more general transitions between modified and Einstein gravity limits. Eachmore » screening or suppression mechanism is parametrised by a time, mass, and environment dependent screening scale, an effective modified gravitational coupling in the fully unscreened limit that can be matched to linear theory, the exponent of a power-law radial profile of the screened coupling, determined by derivatives, symmetries, and potentials in the scalar field equation, and an interpolation rate between the screened and unscreened limits. Along with generalised perturbative methods, the parametrisation may be used to formulate a nonlinear extension to the linear parametrised post-Friedmannian framework to enable generalised tests of gravity with the wealth of observations from the nonlinear cosmological regime.« less

  2. Effect of fine dust particles and finite electron inertia of rotating magnetized plasma

    NASA Astrophysics Data System (ADS)

    Kumar, V.; Sutar, D. L.; Pensia, R. K.; Sharma, S.

    2018-05-01

    A theoretical investigation has been made of the effect of fine dust particles, viscosity and electron inertia on Jeans instability in a self-gravitating magnetized rotating plasma. The MHD model is used to formulate the problem in which a general dispersion relation. A general dispersion relation is obtained from the linearized perturbation equations using the normal mode analysis method. The analytical expressions of the growth rate of Jeans instability are obtained for the longitudinal and transverse mode of propagation. The present result shows that the Jeans criterion of instability is modified due to the presence of viscosity, rotation, and magnetic field.

  3. A Modified Double Multiple Nonlinear Regression Constitutive Equation for Modeling and Prediction of High Temperature Flow Behavior of BFe10-1-2 Alloy

    NASA Astrophysics Data System (ADS)

    Cai, Jun; Wang, Kuaishe; Shi, Jiamin; Wang, Wen; Liu, Yingying

    2018-01-01

    Constitutive analysis for hot working of BFe10-1-2 alloy was carried out by using experimental stress-strain data from isothermal hot compression tests, in a wide range of temperature of 1,023 1,273 K, and strain rate range of 0.001 10 s-1. A constitutive equation based on modified double multiple nonlinear regression was proposed considering the independent effects of strain, strain rate, temperature and their interrelation. The predicted flow stress data calculated from the developed equation was compared with the experimental data. Correlation coefficient (R), average absolute relative error (AARE) and relative errors were introduced to verify the validity of the developed constitutive equation. Subsequently, a comparative study was made on the capability of strain-compensated Arrhenius-type constitutive model. The results showed that the developed constitutive equation based on modified double multiple nonlinear regression could predict flow stress of BFe10-1-2 alloy with good correlation and generalization.

  4. Generalized spherical and simplicial coordinates

    NASA Astrophysics Data System (ADS)

    Richter, Wolf-Dieter

    2007-12-01

    Elementary trigonometric quantities are defined in l2,p analogously to that in l2,2, the sine and cosine functions are generalized for each p>0 as functions sinp and cosp such that they satisfy the basic equation cosp([phi])p+sinp([phi])p=1. The p-generalized radius coordinate of a point [xi][set membership, variant]Rn is defined for each p>0 as . On combining these quantities, ln,p-spherical coordinates are defined. It is shown that these coordinates are nearly related to ln,p-simplicial coordinates. The Jacobians of these generalized coordinate transformations are derived. Applications and interpretations from analysis deal especially with the definition of a generalized surface content on ln,p-spheres which is nearly related to a modified co-area formula and an extension of Cavalieri's and Torricelli's indivisibeln method, and with differential equations. Applications from probability theory deal especially with a geometric interpretation of the uniform probability distribution on the ln,p-sphere and with the derivation of certain generalized statistical distributions.

  5. Nucleic acids encoding modified human immunodeficiency virus type 1 (HIV-1) group M consensus envelope glycoproteins

    DOEpatents

    Haynes, Barton F [Durham, NC; Gao, Feng [Durham, NC; Korber, Bette T [Los Alamos, NM; Hahn, Beatrice H [Birmingham, AL; Shaw, George M [Birmingham, AL; Kothe, Denise [Birmingham, AL; Li, Ying Ying [Hoover, AL; Decker, Julie [Alabaster, AL; Liao, Hua-Xin [Chapel Hill, NC

    2011-12-06

    The present invention relates, in general, to an immunogen and, in particular, to an immunogen for inducing antibodies that neutralizes a wide spectrum of HIV primary isolates and/or to an immunogen that induces a T cell immune response. The invention also relates to a method of inducing anti-HIV antibodies, and/or to a method of inducing a T cell immune response, using such an immunogen. The invention further relates to nucleic acid sequences encoding the present immunogens.

  6. Regular black holes in Einstein-Gauss-Bonnet gravity

    NASA Astrophysics Data System (ADS)

    Ghosh, Sushant G.; Singh, Dharm Veer; Maharaj, Sunil D.

    2018-05-01

    Einstein-Gauss-Bonnet theory, a natural generalization of general relativity to a higher dimension, admits a static spherically symmetric black hole which was obtained by Boulware and Deser. This black hole is similar to its general relativity counterpart with a curvature singularity at r =0 . We present an exact 5D regular black hole metric, with parameter (k >0 ), that interpolates between the Boulware-Deser black hole (k =0 ) and the Wiltshire charged black hole (r ≫k ). Owing to the appearance of the exponential correction factor (e-k /r2), responsible for regularizing the metric, the thermodynamical quantities are modified, and it is demonstrated that the Hawking-Page phase transition is achievable. The heat capacity diverges at a critical radius r =rC, where incidentally the temperature is maximum. Thus, we have a regular black hole with Cauchy and event horizons, and evaporation leads to a thermodynamically stable double-horizon black hole remnant with vanishing temperature. The entropy does not satisfy the usual exact horizon area result of general relativity.

  7. Off-diagonal ekpyrotic scenarios and equivalence of modified, massive and/or Einstein gravity

    NASA Astrophysics Data System (ADS)

    Vacaru, Sergiu I.

    2016-01-01

    Using our anholonomic frame deformation method, we show how generic off-diagonal cosmological solutions depending, in general, on all spacetime coordinates and undergoing a phase of ultra-slow contraction can be constructed in massive gravity. In this paper, there are found and studied new classes of locally anisotropic and (in)homogeneous cosmological metrics with open and closed spatial geometries. The late time acceleration is present due to effective cosmological terms induced by nonlinear off-diagonal interactions and graviton mass. The off-diagonal cosmological metrics and related Stückelberg fields are constructed in explicit form up to nonholonomic frame transforms of the Friedmann-Lamaître-Robertson-Walker (FLRW) coordinates. We show that the solutions include matter, graviton mass and other effective sources modeling nonlinear gravitational and matter fields interactions in modified and/or massive gravity, with polarization of physical constants and deformations of metrics, which may explain certain dark energy and dark matter effects. There are stated and analyzed the conditions when such configurations mimic interesting solutions in general relativity and modifications and recast the general Painlevé-Gullstrand and FLRW metrics. Finally, we elaborate on a reconstruction procedure for a subclass of off-diagonal cosmological solutions which describe cyclic and ekpyrotic universes, with an emphasis on open issues and observable signatures.

  8. Anamorphic quasiperiodic universes in modified and Einstein gravity with loop quantum gravity corrections

    NASA Astrophysics Data System (ADS)

    Amaral, Marcelo M.; Aschheim, Raymond; Bubuianu, Laurenţiu; Irwin, Klee; Vacaru, Sergiu I.; Woolridge, Daniel

    2017-09-01

    The goal of this work is to elaborate on new geometric methods of constructing exact and parametric quasiperiodic solutions for anamorphic cosmology models in modified gravity theories, MGTs, and general relativity, GR. There exist previously studied generic off-diagonal and diagonalizable cosmological metrics encoding gravitational and matter fields with quasicrystal like structures, QC, and holonomy corrections from loop quantum gravity, LQG. We apply the anholonomic frame deformation method, AFDM, in order to decouple the (modified) gravitational and matter field equations in general form. This allows us to find integral varieties of cosmological solutions determined by generating functions, effective sources, integration functions and constants. The coefficients of metrics and connections for such cosmological configurations depend, in general, on all spacetime coordinates and can be chosen to generate observable (quasi)-periodic/aperiodic/fractal/stochastic/(super) cluster/filament/polymer like (continuous, stochastic, fractal and/or discrete structures) in MGTs and/or GR. In this work, we study new classes of solutions for anamorphic cosmology with LQG holonomy corrections. Such solutions are characterized by nonlinear symmetries of generating functions for generic off-diagonal cosmological metrics and generalized connections, with possible nonholonomic constraints to Levi-Civita configurations and diagonalizable metrics depending only on a time like coordinate. We argue that anamorphic quasiperiodic cosmological models integrate the concept of quantum discrete spacetime, with certain gravitational QC-like vacuum and nonvacuum structures. And, that of a contracting universe that homogenizes, isotropizes and flattens without introducing initial conditions or multiverse problems.

  9. 12 CFR 332.16 - Protection of Fair Credit Reporting Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Protection of Fair Credit Reporting Act. 332.16... GENERAL POLICY PRIVACY OF CONSUMER FINANCIAL INFORMATION Relation to Other Laws; Effective Date § 332.16 Protection of Fair Credit Reporting Act. Nothing in this part shall be construed to modify, limit, or...

  10. Mysterious Anti-Gravity and Dark-Essence

    NASA Astrophysics Data System (ADS)

    Gu, Je-An

    2013-12-01

    The need of anti-gravity and dark-essence in cosmology is the greatest scientific mystery in the 21st century. This paper presents a personal view of several relevant issues, including the long-standing cosmological constant problem, the newly emerging dark radiation issue, and the basic stability issue of the general-relativity limit in modified gravity.

  11. Mysterious Anti-Gravity and Dark-Essence

    NASA Astrophysics Data System (ADS)

    Gu, Je-An

    2013-01-01

    The need of anti-gravity and dark-essence in cosmology is the greatest scientific mystery in the 21st century. This paper presents a personal view of several relevant issues, including the long-standing cosmological constant problem, the newly emerging dark radiation issue, and the basic stability issue of the general-relativity limit in modified gravity.

  12. Invisible Ink Revealed: Concept, Context, and Chemical Principles of "Cold War" Writing

    ERIC Educational Resources Information Center

    Macrakis, Kristie; Bell, Elizabeth K.; Perry, Dale L.; Sweeder, Ryan D.

    2012-01-01

    By modifying secret writing formulas uncovered from the archives of the East German Ministry of State Security (MfS or Stasi), a novel general chemistry secret writing laboratory was developed. The laboratory combines science and history that highlights several fundamental chemical principles related to the writing. These include catalysis, redox…

  13. Lensing convergence in galaxy clustering in ΛCDM and beyond

    NASA Astrophysics Data System (ADS)

    Villa, Eleonora; Di Dio, Enea; Lepori, Francesca

    2018-04-01

    We study the impact of neglecting lensing magnification in galaxy clustering analyses for future galaxy surveys, considering the ΛCDM model and two extensions: massive neutrinos and modifications of General Relativity. Our study focuses on the biases on the constraints and on the estimation of the cosmological parameters. We perform a comprehensive investigation of these two effects for the upcoming photometric and spectroscopic galaxy surveys Euclid and SKA for different redshift binning configurations. We also provide a fitting formula for the magnification bias of SKA. Our results show that the information present in the lensing contribution does improve the constraints on the modified gravity parameters whereas the lensing constraining power is negligible for the ΛCDM parameters. For photometric surveys the estimation is biased for all the parameters if lensing is not taken into account. This effect is particularly significant for the modified gravity parameters. Conversely for spectroscopic surveys the bias is below one sigma for all the parameters. Our findings show the importance of including lensing in galaxy clustering analyses for testing General Relativity and to constrain the parameters which describe its modifications.

  14. On a modified form of navier-stokes equations for three-dimensional flows.

    PubMed

    Venetis, J

    2015-01-01

    A rephrased form of Navier-Stokes equations is performed for incompressible, three-dimensional, unsteady flows according to Eulerian formalism for the fluid motion. In particular, we propose a geometrical method for the elimination of the nonlinear terms of these fundamental equations, which are expressed in true vector form, and finally arrive at an equivalent system of three semilinear first order PDEs, which hold for a three-dimensional rectangular Cartesian coordinate system. Next, we present the related variational formulation of these modified equations as well as a general type of weak solutions which mainly concern Sobolev spaces.

  15. On a Modified Form of Navier-Stokes Equations for Three-Dimensional Flows

    PubMed Central

    Venetis, J.

    2015-01-01

    A rephrased form of Navier-Stokes equations is performed for incompressible, three-dimensional, unsteady flows according to Eulerian formalism for the fluid motion. In particular, we propose a geometrical method for the elimination of the nonlinear terms of these fundamental equations, which are expressed in true vector form, and finally arrive at an equivalent system of three semilinear first order PDEs, which hold for a three-dimensional rectangular Cartesian coordinate system. Next, we present the related variational formulation of these modified equations as well as a general type of weak solutions which mainly concern Sobolev spaces. PMID:25918743

  16. Local tests of gravitation with Gaia observations of Solar System Objects

    NASA Astrophysics Data System (ADS)

    Hees, Aurélien; Le Poncin-Lafitte, Christophe; Hestroffer, Daniel; David, Pedro

    2018-04-01

    In this proceeding, we show how observations of Solar System Objects with Gaia can be used to test General Relativity and to constrain modified gravitational theories. The high number of Solar System objects observed and the variety of their orbital parameters associated with the impressive astrometric accuracy will allow us to perform local tests of General Relativity. In this communication, we present a preliminary sensitivity study of the Gaia observations on dynamical parameters such as the Sun quadrupolar moment and on various extensions to general relativity such as the parametrized post-Newtonian parameters, the fifth force formalism and a violation of Lorentz symmetry parametrized by the Standard-Model extension framework. We take into account the time sequences and the geometry of the observations that are particular to Gaia for its nominal mission (5 years) and for an extended mission (10 years).

  17. Metric Theories of Gravity: Perturbations and Conservation Laws

    NASA Astrophysics Data System (ADS)

    Petrov, Alexander N.; Kopeikin, Sergei M.; Lompay, Robert R.; Tekin, Bayram

    2017-04-01

    By focusing on the mostly used variational methods, this monograph aspires to give a unified description and comparison of various ways of constructing conserved quantities for perturbations and to study symmetries in general relativity and modified theories of gravity. The main emphasis lies on the field-theoretical covariant formulation of perturbations, the canonical Noether approach and the Belinfante procedure of symmetrisation. The general formalism is applied to build the gauge-invariant cosmological perturbation theory, conserved currents and superpotentials to describe physically important solutions of gravity theories. Meticulous attention is given to the construction of conserved quantities in asymptotically-flat spacetimes as well as in asymptotically constant curvature spacetimes such as the Anti-de Sitter space. Significant part of the book can be used in graduate courses on conservation laws in general relativity.

  18. The application of generalized, cyclic, and modified numerical integration algorithms to problems of satellite orbit computation

    NASA Technical Reports Server (NTRS)

    Chesler, L.; Pierce, S.

    1971-01-01

    Generalized, cyclic, and modified multistep numerical integration methods are developed and evaluated for application to problems of satellite orbit computation. Generalized methods are compared with the presently utilized Cowell methods; new cyclic methods are developed for special second-order differential equations; and several modified methods are developed and applied to orbit computation problems. Special computer programs were written to generate coefficients for these methods, and subroutines were written which allow use of these methods with NASA's GEOSTAR computer program.

  19. The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: constraining modified gravity

    NASA Astrophysics Data System (ADS)

    Mueller, Eva-Maria; Percival, Will; Linder, Eric; Alam, Shadab; Zhao, Gong-Bo; Sánchez, Ariel G.; Beutler, Florian; Brinkmann, Jon

    2018-04-01

    We use baryon acoustic oscillation and redshift space distortion from the completed Baryon Oscillation Spectroscopic Survey, corresponding to Data Release 12 of the Sloan Digital Sky Survey, combined sample analysis in combination with cosmic microwave background, supernova, and redshift space distortion measurements from additional spectroscopic surveys to test deviations from general relativity. We present constraints on several phenomenological models of modified gravity: First, we parametrize the growth of structure using the growth index γ, finding γ = 0.566 ± 0.058 (68 per cent C.L.). Secondly, we modify the relation of the two Newtonian potentials by introducing two additional parameters, GM and GL. In this approach, GM refers to modifications of the growth of structure whereas GL to modification of the lensing potential. We consider a power law to model the redshift dependence of GM and GL as well as binning in redshift space, introducing four additional degrees of freedom, GM(z < 0.5), GM(z > 0.5), GL(z < 0.5), and GL(z > 0.5). At 68 per cent C.L., we measure GM = 0.980 ± 0.096 and GL = 1.082 ± 0.060 for a linear model, GM = 1.01 ± 0.36 and GL = 1.31 ± 0.19 for a cubic model as well as GM(z < 0.5) = 1.26 ± 0.32, GM(z > 0.5) = 0.986 ± 0.022, GL(z < 0.5) = 1.067 ± 0.058, and GL(z > 0.5) = 1.037 ± 0.029. Thirdly, we investigate general scalar tensor theories of gravity, finding the model to be mostly unconstrained by current data. Assuming a one-parameter f(R) model, we can constrain B0 < 7.7 × 10-5 (95 per cent C.L). For all models we considered, we find good agreement with general relativity.

  20. Studies into the nature of cosmic acceleration: Dark energy or a modification to gravity on cosmological scales

    NASA Astrophysics Data System (ADS)

    Dossett, Jason Nicholas

    Since its discovery more than a decade ago, the problem of cosmic acceleration has become one of the largest in cosmology and physics as a whole. An unknown dark energy component of the universe is often invoked to explain this observation. Mathematically, this works because inserting a cosmic fluid with a negative equation of state into Einstein's equations provides an accelerated expansion. There are, however, alternative explanations for the observed cosmic acceleration. Perhaps the most promising of the alternatives is that, on the very largest cosmological scales, general relativity needs to be extended or a new, modified gravity theory must be used. Indeed, many modified gravity models are not only able to replicate the observed accelerated expansion without dark energy, but are also more compatible with a unified theory of physics. Thus it is the goal of this dissertation to develop and study robust tests that will be able to distinguish between these alternative theories of gravity and the need for a dark energy component of the universe. We will study multiple approaches using the growth history of large-scale structure in the universe as a way to accomplish this task. These approaches include studying what is known as the growth index parameter, a parameter that describes the logarithmic growth rate of structure in the universe, which describes the rate of formation of clusters and superclusters of galaxies over the entire age of the universe. We will explore the effectiveness of this parameter to distinguish between general relativity and modifications to gravity physics given realistic expectations of results from future experiments. Next, we will explore the modified growth formalism wherein deviations from the growth expected in general relativity are parameterized via changes to the growth equations, i.e. the perturbed Einstein's equations. We will also explore the impact of spatial curvature on these tests. Finally, we will study how dark energy with some unusual properties will affect the conclusiveness of these tests.

  1. A new smoothing modified three-term conjugate gradient method for [Formula: see text]-norm minimization problem.

    PubMed

    Du, Shouqiang; Chen, Miao

    2018-01-01

    We consider a kind of nonsmooth optimization problems with [Formula: see text]-norm minimization, which has many applications in compressed sensing, signal reconstruction, and the related engineering problems. Using smoothing approximate techniques, this kind of nonsmooth optimization problem can be transformed into a general unconstrained optimization problem, which can be solved by the proposed smoothing modified three-term conjugate gradient method. The smoothing modified three-term conjugate gradient method is based on Polak-Ribière-Polyak conjugate gradient method. For the Polak-Ribière-Polyak conjugate gradient method has good numerical properties, the proposed method possesses the sufficient descent property without any line searches, and it is also proved to be globally convergent. Finally, the numerical experiments show the efficiency of the proposed method.

  2. Out-of-time-order fluctuation-dissipation theorem

    NASA Astrophysics Data System (ADS)

    Tsuji, Naoto; Shitara, Tomohiro; Ueda, Masahito

    2018-01-01

    We prove a generalized fluctuation-dissipation theorem for a certain class of out-of-time-ordered correlators (OTOCs) with a modified statistical average, which we call bipartite OTOCs, for general quantum systems in thermal equilibrium. The difference between the bipartite and physical OTOCs defined by the usual statistical average is quantified by a measure of quantum fluctuations known as the Wigner-Yanase skew information. Within this difference, the theorem describes a universal relation between chaotic behavior in quantum systems and a nonlinear-response function that involves a time-reversed process. We show that the theorem can be generalized to higher-order n -partite OTOCs as well as in the form of generalized covariance.

  3. Dark matter (energy) may be indistinguishable from modified gravity (MOND)

    NASA Astrophysics Data System (ADS)

    Sivaram, C.

    For Newtonian dynamics to hold over galactic scales, large amounts of dark matter (DM) are required which would dominate cosmic structures. Accounting for the strong observational evidence that the universe is accelerating requires the presence of an unknown dark energy (DE) component constituting about 70% of the matter. Several ingenious ongoing experiments to detect the DM particles have so far led to negative results. Moreover, the comparable proportions of the DM and DE at the present epoch appear unnatural and not predicted by any theory. For these reasons, alternative ideas like MOND and modification of gravity or general relativity over cosmic scales have been proposed. It is shown in this paper that these alternate ideas may not be easily distinguishable from the usual DM or DE hypotheses. Specific examples are given to illustrate this point that the modified theories are special cases of a generalized DM paradigm.

  4. Large-scale 3D galaxy correlation function and non-Gaussianity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Raccanelli, Alvise; Doré, Olivier; Bertacca, Daniele

    We investigate the properties of the 2-point galaxy correlation function at very large scales, including all geometric and local relativistic effects --- wide-angle effects, redshift space distortions, Doppler terms and Sachs-Wolfe type terms in the gravitational potentials. The general three-dimensional correlation function has a nonzero dipole and octupole, in addition to the even multipoles of the flat-sky limit. We study how corrections due to primordial non-Gaussianity and General Relativity affect the multipolar expansion, and we show that they are of similar magnitude (when f{sub NL} is small), so that a relativistic approach is needed. Furthermore, we look at how large-scalemore » corrections depend on the model for the growth rate in the context of modified gravity, and we discuss how a modified growth can affect the non-Gaussian signal in the multipoles.« less

  5. Consumers' acceptance and preferences for nutrition-modified and functional dairy products: A systematic review.

    PubMed

    Bimbo, Francesco; Bonanno, Alessandro; Nocella, Giuseppe; Viscecchia, Rosaria; Nardone, Gianluca; De Devitiis, Biagia; Carlucci, Domenico

    2017-06-01

    This systematic literature review collects and summarizes research on consumer acceptance and preferences for nutrition-modified and functional dairy products, to reconcile, and expand upon, the findings of previous studies. We find that female consumers show high acceptance for some functional dairy products, such as yogurt enriched with calcium, fiber and probiotics. Acceptance for functional dairy products increases among consumers with higher diet/health related knowledge, as well as with aging. General interest in health, food-neophobia and perceived self-efficacy seem also to contribute shaping the acceptance for functional dairy products. Furthermore, products with "natural" matches between carriers and ingredients have the highest level of acceptance among consumers. Last, we find that brand familiarity drives consumers with low interest in health to increase their acceptance and preference for health-enhanced dairy products, such as probiotic yogurts, or those with a general function claim. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Reconstruction of cosmological matter perturbations in modified gravity

    NASA Astrophysics Data System (ADS)

    Gonzalez, J. E.

    2017-12-01

    The analysis of perturbative quantities is a powerful tool to distinguish between different dark energy models and gravity theories degenerated at the background level. In this work, we generalize the integral solution of the matter density contrast for general relativity gravity [V. Sahni and A. Starobinsky, Int. J. Mod. Phys. D 15, 2105 (2006)., 10.1142/S0218271806009704, U. Alam, V. Sahni, and A. A. Starobinsky, Astrophys. J. 704, 1086 (2009)., 10.1088/0004-637X/704/2/1086] to a wide class of modified gravity (MG) theories. To calculate this solution, it is necessary to have prior knowledge of the Hubble rate, the density parameter at the present epoch (Ωm 0), and the functional form of the effective Newton's constant that characterizes the gravity theory. We estimate in a model-independent way the Hubble expansion rate by applying a nonparametric reconstruction method to model-independent cosmic chronometer data and high-z quasar data. In order to compare our generalized solution of the matter density contrast, using the nonparametric reconstruction of H (z ) from observational data, with a purely theoretical one, we choose a parametrization of the screened modified gravity and the Ωm 0 from WMAP-9 Collaborations. Finally, we calculate the growth index for the analyzed cases, finding very good agreement between theoretical values and the obtained ones using the approach presented in this work.

  7. General PFG signal attenuation expressions for anisotropic anomalous diffusion by modified-Bloch equations

    NASA Astrophysics Data System (ADS)

    Lin, Guoxing

    2018-05-01

    Anomalous diffusion exists widely in polymer and biological systems. Pulsed-field gradient (PFG) anomalous diffusion is complicated, especially in the anisotropic case where limited research has been reported. A general PFG signal attenuation expression, including the finite gradient pulse (FGPW) effect for free general anisotropic fractional diffusion { 0 < α , β ≤ 2 } based on the fractional derivative, has not been obtained, where α and β are time and space derivative orders. It is essential to derive a general PFG signal attenuation expression including the FGPW effect for PFG anisotropic anomalous diffusion research. In this paper, two recently developed modified-Bloch equations, the fractal differential modified-Bloch equation and the fractional integral modified-Bloch equation, were extended to obtain general PFG signal attenuation expressions for anisotropic anomalous diffusion. Various cases of PFG anisotropic anomalous diffusion were investigated, including coupled and uncoupled anisotropic anomalous diffusion. The continuous-time random walk (CTRW) simulation was also carried out to support the theoretical results. The theory and the CTRW simulation agree with each other. The obtained signal attenuation expressions and the three-dimensional fractional modified-Bloch equations are important for analyzing PFG anisotropic anomalous diffusion in NMR and MRI.

  8. Doing Dissections Differently: A Structured, Peer-Assisted Learning Approach to Maximizing Learning in Dissections

    ERIC Educational Resources Information Center

    Hall, Emma R.; Davis, Rachel C.; Weller, Renate; Powney, Sonya; Williams, Sarah B.

    2013-01-01

    Areas of difficulty faced by our veterinary medicine students, with respect to their learning in dissection classes, were identified. These challenges were both general adult-learning related and specific to the discipline of anatomy. Our aim was to design, implement, and evaluate a modified reciprocal peer-assisted/team-based learning…

  9. On the validity of the modified equation approach to the stability analysis of finite-difference methods

    NASA Technical Reports Server (NTRS)

    Chang, Sin-Chung

    1987-01-01

    The validity of the modified equation stability analysis introduced by Warming and Hyett was investigated. It is shown that the procedure used in the derivation of the modified equation is flawed and generally leads to invalid results. Moreover, the interpretation of the modified equation as the exact partial differential equation solved by a finite-difference method generally cannot be justified even if spatial periodicity is assumed. For a two-level scheme, due to a series of mathematical quirks, the connection between the modified equation approach and the von Neuman method established by Warming and Hyett turns out to be correct despite its questionable original derivation. However, this connection is only partially valid for a scheme involving more than two time levels. In the von Neumann analysis, the complex error multiplication factor associated with a wave number generally has (L-1) roots for an L-level scheme. It is shown that the modified equation provides information about only one of these roots.

  10. Constraining the noncommutative spectral action via astrophysical observations.

    PubMed

    Nelson, William; Ochoa, Joseph; Sakellariadou, Mairi

    2010-09-03

    The noncommutative spectral action extends our familiar notion of commutative spaces, using the data encoded in a spectral triple on an almost commutative space. Varying a rather simple action, one can derive all of the standard model of particle physics in this setting, in addition to a modified version of Einstein-Hilbert gravity. In this Letter we use observations of pulsar timings, assuming that no deviation from general relativity has been observed, to constrain the gravitational sector of this theory. While the bounds on the coupling constants remain rather weak, they are comparable to existing bounds on deviations from general relativity in other settings and are likely to be further constrained by future observations.

  11. The AIROPA software package: milestones for testing general relativity in the strong gravity regime with AO

    NASA Astrophysics Data System (ADS)

    Witzel, Gunther; Lu, Jessica R.; Ghez, Andrea M.; Martinez, Gregory D.; Fitzgerald, Michael P.; Britton, Matthew; Sitarski, Breann N.; Do, Tuan; Campbell, Randall D.; Service, Maxwell; Matthews, Keith; Morris, Mark R.; Becklin, E. E.; Wizinowich, Peter L.; Ragland, Sam; Doppmann, Greg; Neyman, Chris; Lyke, James; Kassis, Marc; Rizzi, Luca; Lilley, Scott; Rampy, Rachel

    2016-07-01

    General relativity can be tested in the strong gravity regime by monitoring stars orbiting the supermassive black hole at the Galactic Center with adaptive optics. However, the limiting source of uncertainty is the spatial PSF variability due to atmospheric anisoplanatism and instrumental aberrations. The Galactic Center Group at UCLA has completed a project developing algorithms to predict PSF variability for Keck AO images. We have created a new software package (AIROPA), based on modified versions of StarFinder and Arroyo, that takes atmospheric turbulence profiles, instrumental aberration maps, and images as inputs and delivers improved photometry and astrometry on crowded fields. This software package will be made publicly available soon.

  12. Gravitational waves in modified teleparallel theories of gravity.

    PubMed

    Abedi, Habib; Capozziello, Salvatore

    2018-01-01

    Teleparallel theory of gravity and its modifications have been studied extensively in literature. However, gravitational waves has not been studied enough in the framework of teleparallelism. In the present study, we discuss gravitational waves in general theories of teleparallel gravity containing the torsion scalar T , the boundary term B and a scalar field ϕ . The goal is to classify possible new polarizations generalizing results presented in Bamba et al. (Phys Lett B 727:194-198, arXiv:1309.2698, 2013). We show that, if the boundary term is minimally coupled to the torsion scalar and the scalar field, gravitational waves have the same polarization modes of General Relativity.

  13. Gravitational waves in modified teleparallel theories of gravity

    NASA Astrophysics Data System (ADS)

    Abedi, Habib; Capozziello, Salvatore

    2018-06-01

    Teleparallel theory of gravity and its modifications have been studied extensively in literature. However, gravitational waves has not been studied enough in the framework of teleparallelism. In the present study, we discuss gravitational waves in general theories of teleparallel gravity containing the torsion scalar T, the boundary term B and a scalar field φ . The goal is to classify possible new polarizations generalizing results presented in Bamba et al. (Phys Lett B 727:194-198, arXiv:1309.2698, 2013). We show that, if the boundary term is minimally coupled to the torsion scalar and the scalar field, gravitational waves have the same polarization modes of General Relativity.

  14. Weighted density fields as improved probes of modified gravity models

    NASA Astrophysics Data System (ADS)

    Llinares, Claudio; McCullagh, Nuala

    2017-11-01

    When it comes to searches for extensions to general relativity, large efforts are being dedicated to accurate predictions for the power spectrum of density perturbations. While this observable is known to be sensitive to the gravitational theory, its efficiency as a diagnostic for gravity is significantly reduced when Solar system constraints are strictly adhered to. We show that this problem can be overcome by studying weighted density fields. We propose a transformation of the density field for which the impact of modified gravity on the power spectrum can be increased by more than a factor of three. The signal is not only amplified, but the modified gravity features are shifted to larger scales that are less affected by baryonic physics. Furthermore, the overall signal-to-noise ratio increases, which in principle makes identifying signatures of modified gravity with future galaxy surveys more feasible. While our analysis is focused on modified gravity, the technique can be applied to other problems in cosmology, such as the detection of neutrinos, the effects of baryons or baryon acoustic oscillations.

  15. Generalized uncertainty principle and quantum gravity phenomenology

    NASA Astrophysics Data System (ADS)

    Bosso, Pasquale

    The fundamental physical description of Nature is based on two mutually incompatible theories: Quantum Mechanics and General Relativity. Their unification in a theory of Quantum Gravity (QG) remains one of the main challenges of theoretical physics. Quantum Gravity Phenomenology (QGP) studies QG effects in low-energy systems. The basis of one such phenomenological model is the Generalized Uncertainty Principle (GUP), which is a modified Heisenberg uncertainty relation and predicts a deformed canonical commutator. In this thesis, we compute Planck-scale corrections to angular momentum eigenvalues, the hydrogen atom spectrum, the Stern-Gerlach experiment, and the Clebsch-Gordan coefficients. We then rigorously analyze the GUP-perturbed harmonic oscillator and study new coherent and squeezed states. Furthermore, we introduce a scheme for increasing the sensitivity of optomechanical experiments for testing QG effects. Finally, we suggest future projects that may potentially test QG effects in the laboratory.

  16. Frame-dragging effect in the field of non rotating body due to unit gravimagnetic moment

    NASA Astrophysics Data System (ADS)

    Deriglazov, Alexei A.; Ramírez, Walberto Guzmán

    2018-04-01

    Nonminimal spin-gravity interaction through unit gravimagnetic moment leads to modified Mathisson-Papapetrou-Tulczyjew-Dixon equations with improved behavior in the ultrarelativistic limit. We present exact Hamiltonian of the resulting theory and compute an effective 1/c2-Hamiltonian and leading post-Newtonian corrections to the trajectory and spin. Gravimagnetic moment causes the same precession of spin S as a fictitious rotation of the central body with angular momentum J = M/m S. So the modified equations imply a number of qualitatively new effects, that could be used to test experimentally, whether a rotating body in general relativity has null or unit gravimagnetic moment.

  17. Modified Lagrange invariants and their role in determining transverse and axial imaging resolutions of self-interference incoherent holographic systems.

    PubMed

    Rosen, Joseph; Kelner, Roy

    2014-11-17

    The Lagrange invariant is a well-known law for optical imaging systems formulated in the frame of ray optics. In this study, we reformulate this law in terms of wave optics and relate it to the resolution limits of various imaging systems. Furthermore, this modified Lagrange invariant is generalized for imaging along the z axis, resulting with the axial Lagrange invariant which can be used to analyze the axial resolution of various imaging systems. To demonstrate the effectiveness of the theory, analysis of the lateral and the axial imaging resolutions is provided for Fresnel incoherent correlation holography (FINCH) systems.

  18. Comparison between modified Misgav-Ladach and Pfannenstiel-Kerr techniques for Cesarean section: review of literature

    PubMed Central

    Vitale, Salvatore Giovanni; Marilli, Ilaria; Cignini, Pietro; Padula, Francesco; D’Emidio, Laura; Mangiafico, Lucia; Rapisarda, Agnese Maria Chiara; Gulino, Ferdinando Antonio; Cianci, Stefano; Biondi, Antonio; Giorlandino, Claudio

    2014-01-01

    In the last decades cesarean section rates increased in many countries becoming the most performed intraperitoneal surgical procedure. Despite its worldwide spread, a general consensus on the most appropriate technique to use has not yet been reached. The operative technique performed is made chiefly on the basis of the individual experience and preference of operators, the characteristics of patients, timing and urgency of intervention. We compared the two most known and used techniques, modified Misgav-Ladach and traditional Pfannenstiel-Kerr, and analyzed their impact on primary, short- and long-term outcomes and outcome related to health service use. PMID:26265999

  19. Comparison between modified Misgav-Ladach and Pfannenstiel-Kerr techniques for Cesarean section: review of literature.

    PubMed

    Vitale, Salvatore Giovanni; Marilli, Ilaria; Cignini, Pietro; Padula, Francesco; D'Emidio, Laura; Mangiafico, Lucia; Rapisarda, Agnese Maria Chiara; Gulino, Ferdinando Antonio; Cianci, Stefano; Biondi, Antonio; Giorlandino, Claudio

    2014-01-01

    In the last decades cesarean section rates increased in many countries becoming the most performed intraperitoneal surgical procedure. Despite its worldwide spread, a general consensus on the most appropriate technique to use has not yet been reached. The operative technique performed is made chiefly on the basis of the individual experience and preference of operators, the characteristics of patients, timing and urgency of intervention. We compared the two most known and used techniques, modified Misgav-Ladach and traditional Pfannenstiel-Kerr, and analyzed their impact on primary, short- and long-term outcomes and outcome related to health service use.

  20. Goal-setting in clinical medicine.

    PubMed

    Bradley, E H; Bogardus, S T; Tinetti, M E; Inouye, S K

    1999-07-01

    The process of setting goals for medical care in the context of chronic disease has received little attention in the medical literature, despite the importance of goal-setting in the achievement of desired outcomes. Using qualitative research methods, this paper develops a theory of goal-setting in the care of patients with dementia. The theory posits several propositions. First, goals are generated from embedded values but are distinct from values. Goals vary based on specific circumstances and alternatives whereas values are person-specific and relatively stable in the face of changing circumstances. Second, goals are hierarchical in nature, with complex mappings between general and specific goals. Third, there are a number of factors that modify the goal-setting process, by affecting the generation of goals from values or the translation of general goals to specific goals. Modifying factors related to individuals include their degree of risk-taking, perceived self-efficacy, and acceptance of the disease. Disease factors that modify the goal-setting process include the urgency and irreversibility of the medical condition. Pertinent characteristics of the patient-family-clinician interaction include the level of participation, control, and trust among patients, family members, and clinicians. The research suggests that the goal-setting process in clinical medicine is complex, and the potential for disagreements regarding goals substantial. The nature of the goal-setting process suggests that explicit discussion of goals for care may be necessary to promote effective patient-family-clinician communication and adequate care planning.

  1. Testing gravity with EG: mapping theory onto observations

    NASA Astrophysics Data System (ADS)

    Leonard, C. Danielle; Ferreira, Pedro G.; Heymans, Catherine

    2015-12-01

    We present a complete derivation of the observationally motivated definition of the modified gravity statistic EG. Using this expression, we investigate how variations to theory and survey parameters may introduce uncertainty in the general relativistic prediction of EG. We forecast errors on EG for measurements using two combinations of upcoming surveys, and find that theoretical uncertainties may dominate for a futuristic measurement. Finally, we compute predictions of EG under modifications to general relativity in the quasistatic regime, and comment on the pros and cons of using EG to test gravity with future surveys.

  2. Importance and management of micronutrient deficiencies in patients with Alzheimer’s disease

    PubMed Central

    Cardoso, Bárbara Rita; Cominetti, Cristiane; Cozzolino, Silvia Maria Franciscato

    2013-01-01

    Alzheimer’s disease (AD) is the most common form of dementia, and it generally affects the elderly. It has been suggested that diet is an intensively modifiable lifestyle factor that might reduce the risk of AD. Because epidemiological studies generally report the potential neuronal protective effects of various micronutrients, the aim of this study was to perform a literature review on the major nutrients that are related to AD, including selenium, vitamins C and E, transition metals, vitamin D, B-complex vitamins, and omega-3 fatty acids. PMID:23696698

  3. Selfish genes, pleiotropy and the origin of recombination.

    PubMed Central

    Hey, J

    1998-01-01

    If multiple linked polymorphisms are under natural selection, then conflicts arise and the efficiency of natural selection is hindered relative to the case of no linkage. This simple interaction between linkage and natural selection creates an opportunity for mutations that raise the level of recombination to increase in frequency and have an enhanced chance of fixation. This important finding by S. Otto and N. Barton means that mutations that raise the recombination rate, but are otherwise neutral, will be selectively favored under fairly general circumstances of multilocus selection and linkage. The effect described by Otto and Barton, which was limited to neutral modifiers, can also be extended to include all modifiers of recombination, both beneficial and deleterious. Computer simulations show that beneficial mutations that also increase recombination have an increased chance of fixation. Similarly, deleterious mutations that also decrease recombination have an increased chance of fixation. The results suggest that a simple model of recombination modifiers, including both neutral and pleiotropic modifiers, is a necessary explanation for the evolutionary origin of recombination. PMID:9691060

  4. Clear and Measurable Signature of Modified Gravity in the Galaxy Velocity Field

    NASA Astrophysics Data System (ADS)

    Hellwing, Wojciech A.; Barreira, Alexandre; Frenk, Carlos S.; Li, Baojiu; Cole, Shaun

    2014-06-01

    The velocity field of dark matter and galaxies reflects the continued action of gravity throughout cosmic history. We show that the low-order moments of the pairwise velocity distribution v12 are a powerful diagnostic of the laws of gravity on cosmological scales. In particular, the projected line-of-sight galaxy pairwise velocity dispersion σ12(r) is very sensitive to the presence of modified gravity. Using a set of high-resolution N-body simulations, we compute the pairwise velocity distribution and its projected line-of-sight dispersion for a class of modified gravity theories: the chameleon f(R) gravity and Galileon gravity (cubic and quartic). The velocities of dark matter halos with a wide range of masses would exhibit deviations from general relativity at the (5-10)σ level. We examine strategies for detecting these deviations in galaxy redshift and peculiar velocity surveys. If detected, this signature would be a "smoking gun" for modified gravity.

  5. 78 FR 39947 - To Modify Duty-Free Treatment Under the Generalized System of Preferences and for Other Purposes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... Treatment Under the Generalized System of Preferences and for Other Purposes #0; #0; #0; Presidential... Modify Duty-Free Treatment Under the Generalized System of Preferences and for Other Purposes By the... competitive need limitations on the preferential treatment afforded under the GSP to eligible articles. 4...

  6. Generalization of the quasi-geostrophic Eliassen-Palm flux to include eddy forcing of condensation heating

    NASA Technical Reports Server (NTRS)

    Stone, P. H.; Salustri, G.

    1984-01-01

    A modified Eulerian form of the Eliassen-Palm flux which includes the effect of eddy forcing on condensation heating is defined. With the two-dimensional vector flux in the meridional plane which is a function of the zonal mean eddy fluxes replaced by the modified flux, both the Eliassen-Palm theorem and a modified but more general form of the nonacceleration theorem for quasi-geostrophic motion still hold. Calculations of the divergence of the modified flux and of the eddy forcing of the moisture field are presented.

  7. The association of health and voluntary early retirement pension and the modifying effect of quality of supervision: Results from a Danish register-based follow-up study.

    PubMed

    Wind, Astrid de; Burr, Hermann; Pohrt, Anne; Hasselhorn, Hans Martin; Van der Beek, Allard Johan; Rugulies, Reiner

    2017-07-01

    The aims of this article are to (1) determine whether and to what extent general perceived health and quality of supervision predict voluntary early retirement pension (VERP) and (2) assess whether quality of supervision modifies the association between general perceived health and VERP. Employees aged 49-64 years who participated in the Danish Work Environment Cohort Study in 2000 were selected. Their questionnaire data about health and work were linked to register data on social transfer payments, among others VERP, from 2001 to 2012 in the Danish Register for Evaluation of Marginalization ( N=1167). Cox proportional hazards analyses were performed to identify the prospective association of general perceived health and quality of supervision on VERP. Relative excess risks due to interaction (RERIs) were calculated to assess whether quality of supervision modified the association between health and VERP. Employees with poor health at baseline had an increased risk of VERP during follow-up (hazard ratio [HR]=1.23; 95% confidence interval [CI] 1.02-1.49). Quality of supervision at baseline was not associated to VERP during follow-up (HR=1.04; 95% CI 0.90-1.21). There was no statistically significant interaction of poor health and poor quality of supervision with regard to risk of VERP (RERI=-0.33; 95% CI -1.79 to 1.14). This study did not support the notion that quality of supervision buffers the association between poor health and VERP. Future research is needed to determine whether other aspects of supervision, for example supervisors' opportunities to effectuate workplace adjustments, may modify the association of poor health and VERP.

  8. The association of health and voluntary early retirement pension and the modifying effect of quality of supervision: Results from a Danish register-based follow-up study

    PubMed Central

    de Wind, Astrid; Burr, Hermann; Pohrt, Anne; Hasselhorn, Hans Martin; Van der Beek, Allard Johan; Rugulies, Reiner

    2017-01-01

    Objectives: The aims of this article are to (1) determine whether and to what extent general perceived health and quality of supervision predict voluntary early retirement pension (VERP) and (2) assess whether quality of supervision modifies the association between general perceived health and VERP. Methods: Employees aged 49–64 years who participated in the Danish Work Environment Cohort Study in 2000 were selected. Their questionnaire data about health and work were linked to register data on social transfer payments, among others VERP, from 2001 to 2012 in the Danish Register for Evaluation of Marginalization (N=1167). Cox proportional hazards analyses were performed to identify the prospective association of general perceived health and quality of supervision on VERP. Relative excess risks due to interaction (RERIs) were calculated to assess whether quality of supervision modified the association between health and VERP. Results: Employees with poor health at baseline had an increased risk of VERP during follow-up (hazard ratio [HR]=1.23; 95% confidence interval [CI] 1.02–1.49). Quality of supervision at baseline was not associated to VERP during follow-up (HR=1.04; 95% CI 0.90–1.21). There was no statistically significant interaction of poor health and poor quality of supervision with regard to risk of VERP (RERI=−0.33; 95% CI −1.79 to 1.14). Conclusions: This study did not support the notion that quality of supervision buffers the association between poor health and VERP. Future research is needed to determine whether other aspects of supervision, for example supervisors’ opportunities to effectuate workplace adjustments, may modify the association of poor health and VERP. PMID:28381121

  9. Comparison of microfacet BRDF model to modified Beckmann-Kirchhoff BRDF model for rough and smooth surfaces.

    PubMed

    Butler, Samuel D; Nauyoks, Stephen E; Marciniak, Michael A

    2015-11-02

    A popular class of BRDF models is the microfacet models, where geometric optics is assumed. In contrast, more complex physical optics models may more accurately predict the BRDF, but the calculation is more resource intensive. These seemingly disparate approaches are compared in detail for the rough and smooth surface approximations of the modified Beckmann-Kirchhoff BRDF model, assuming Gaussian surface statistics. An approximation relating standard Fresnel reflection with the semi-rough surface polarization term, Q, is presented for unpolarized light. For rough surfaces, the angular dependence of direction cosine space is shown to be identical to the angular dependence in the microfacet distribution function. For polished surfaces, the same comparison shows a breakdown in the microfacet models. Similarities and differences between microfacet BRDF models and the modified Beckmann-Kirchhoff model are identified. The rationale for the original Beckmann-Kirchhoff F(bk)(2) geometric term relative to both microfacet models and generalized Harvey-Shack model is presented. A modification to the geometric F(bk)(2) term in original Beckmann-Kirchhoff BRDF theory is proposed.

  10. A cosmological Slavnov-Taylor identity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Collins, Hael; Holman, R.; Vardanyan, Tereza, E-mail: hcollins@andrew.cmu.edu, E-mail: rh4a@andrew.cmu.edu, E-mail: tvardany@andrew.cmu.edu

    We develop a method for treating the consistency relations of inflation that includes the full time-evolution of the state. This approach relies only on the symmetries of the inflationary setting, in particular a residual conformal symmetry in the spatial part of the metric, along with general properties which hold for any quantum field theory. As a result, the consistency relations that emerge, which are essentially the Slavnov-Taylor identities associated with this residual conformal symmetry, apply very generally: they are true of the full Green's functions, hold largely independently of the particular inflationary model, and can be used for arbitrary states.more » We illustrate these techniques by showing the form assumed by the standard consistency relation between the two and three-point functions for the primordial scalar fluctuations when they are in a Bunch-Davies state. But because we have included the full evolution of the state, this approach works for a general initial state as well and does not need to have assumed that inflation began in the Bunch-Davies state. We explain how the Slavnov-Taylor identity is modified for these more general states.« less

  11. Perceptions of teachers' general and informational feedback and intrinsic motivation in physical education: two-year effects.

    PubMed

    Koka, Andre; Hein, Vello

    2006-10-01

    Relative change or stability of perceived positive general feedback and perceived informational feedback and their influence on students' intrinsic motivation in physical education over two years were examined. 302 students, ages 11 to 15 years, responded to the Perception of Teacher's Feedback questionnaire. Two years later, these students filled out the questionnaire again, along with a modified version of the Sport Motivation Scale. Analysis showed that both types of perceived feedback exhibited moderate stability over the two years. Perceived positive general feedback demonstrated a significant direct effect on students' intrinsic motivation measured concurrently in physical education. Further, fixing to zero the effect of perceived positive general feedback on intrinsic motivation measured concurrently, an effect emerged over the two years.

  12. Generalized Kramers-Kronig relations in nonlinear optical- and THz-spectroscopy

    NASA Astrophysics Data System (ADS)

    Peiponen, K.-E.; Saarinen, J. J.

    2009-05-01

    Kramers-Kronig (K-K) relations have constituted one of the principal tools in the optical spectroscopy for the assessment of the optical properties of media from measured spectra. The underlying principle for the existence of the K-K relations is causality. Thanks to the K-K relations we have achieved a better understanding of both macroscopic and microscopic properties of media. Recently, various kinds of modified K-K relations have been presented in the literature. Such relations have been applied, e.g. to the nonlinear optical properties of polymers. A typical advantage of these generalized K-K relations is that the measured data do not need to be manipulated as in the case of the traditional K-K relations. Hence, the accuracy of the inverted data on linear or nonlinear optical properties of media becomes higher. A novel way to utilize generalized K-K relations is related to the measurement and correction of terahertz spectra in the time-domain reflection spectroscopy. Terahertz spectroscopy is nowadays one of the most rapidly developing fields in modern physics with applications being related to, e.g. security at the airports or inspection of pharmaceutical tablets. While recording THz spectra it is also possible to perform a chemical mapping of species. Therefore, correctness of the spectrum is of crucial importance for the identification of different species. This is possible by the generalized K-K relations. In this review paper we consider advances of K-K relations both in nonlinear optical and THz spectroscopy.

  13. 46 CFR 52.05-1 - General (modifies PW-1 through PW-54).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... BOILERS Requirements for Boilers Fabricated by Welding § 52.05-1 General (modifies PW-1 through PW-54). (a) Boilers and component parts, including piping, that are fabricated by welding shall be as indicated in PW...

  14. 46 CFR 52.05-1 - General (modifies PW-1 through PW-54).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... BOILERS Requirements for Boilers Fabricated by Welding § 52.05-1 General (modifies PW-1 through PW-54). (a) Boilers and component parts, including piping, that are fabricated by welding shall be as indicated in PW...

  15. 46 CFR 52.05-1 - General (modifies PW-1 through PW-54).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... BOILERS Requirements for Boilers Fabricated by Welding § 52.05-1 General (modifies PW-1 through PW-54). (a) Boilers and component parts, including piping, that are fabricated by welding shall be as indicated in PW...

  16. 46 CFR 52.05-1 - General (modifies PW-1 through PW-54).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... BOILERS Requirements for Boilers Fabricated by Welding § 52.05-1 General (modifies PW-1 through PW-54). (a) Boilers and component parts, including piping, that are fabricated by welding shall be as indicated in PW...

  17. 46 CFR 52.05-1 - General (modifies PW-1 through PW-54).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... BOILERS Requirements for Boilers Fabricated by Welding § 52.05-1 General (modifies PW-1 through PW-54). (a) Boilers and component parts, including piping, that are fabricated by welding shall be as indicated in PW...

  18. Relationship among Students' Attitudes, Intentions and Behaviors towards the Inclusion of Peers with Disabilities, in Mainstream Physical Education Classes

    ERIC Educational Resources Information Center

    Bebetsos, Evangelos; Zafeiriadis, Stratos; Derri, Vassiliki; Kyrgiridis, Pavlos

    2013-01-01

    Students' attitudes, intentions and behaviours towards their peers with disabilities are important to their mutual co-existence and development. The aim of this study was to investigate a) whether students' attitudes and intentions towards their schoolmates with disabilities are related to their general and modified behavior in mainstream physical…

  19. Combined Electrical Stimulation and Exercise for Swallow Rehabilitation Post-Stroke: A Pilot Randomized Control Trial

    ERIC Educational Resources Information Center

    Sproson, Lise; Pownall, Sue; Enderby, Pam; Freeman, Jenny

    2018-01-01

    Background: Dysphagia is common after stroke, affecting up to 50% of patients initially. It can lead to post-stroke pneumonia, which causes 30% of stroke-related deaths, a longer hospital stay and poorer health outcomes. Dysphagia care post-stroke generally focuses on the management of symptoms, via modified oral intake textures and adapted…

  20. Jeans instability of rotating magnetized quantum plasma: Influence of radiation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Joshi, H., E-mail: hjoshi8525@yahoo.com; Pensia, R. K.

    2015-07-31

    The effect of radiative heat-loss function and rotation on the Jeans instability of quantum plasma is investigated. The basic set of equations for this problem is constructed by considering quantum magnetohydrodynamic (QMHD) model. Using normal mode analysis, the general dispersion relation is obtained. This dispersion relation is studied in both, longitudinal and transverse direction of propagations. In both case of longitudinal and transverse direction of propagation, the Jeans instability criterion is modified due to presence of radiative heat-loss function and quantum correction.

  1. Casimir effect in the rainbow Einstein's universe

    NASA Astrophysics Data System (ADS)

    Bezerra, V. B.; Mota, H. F.; Muniz, C. R.

    2017-10-01

    In the present paper we investigate the effects caused by the modification of the dispersion relation obtained by solving the Klein-Gordon equation in the closed Einstein's universe in the context of rainbow's gravity models. Thus, we analyse how the quantum vacuum fluctuations of the scalar field are modified when compared with the results obtained in the usual General Relativity scenario. The regularization, and consequently the renormalization, of the vacuum energy is performed adopting the Epstein-Hurwitz and Riemann's zeta functions.

  2. Deforming black hole and cosmological solutions by quasiperiodic and/or pattern forming structures in modified and Einstein gravity

    NASA Astrophysics Data System (ADS)

    Bubuianu, Laurenţiu; Vacaru, Sergiu I.

    2018-05-01

    We elaborate on the anholonomic frame deformation method, AFDM, for constructing exact solutions with quasiperiodic structure in modified gravity theories, MGTs, and general relativity, GR. Such solutions are described by generic off-diagonal metrics, nonlinear and linear connections and (effective) matter sources with coefficients depending on all spacetime coordinates via corresponding classes of generation and integration functions and (effective) matter sources. There are studied effective free energy functionals and nonlinear evolution equations for generating off-diagonal quasiperiodic deformations of black hole and/or homogeneous cosmological metrics. The physical data for such functionals are stated by different values of constants and prescribed symmetries for defining quasiperiodic structures at cosmological scales, or astrophysical objects in nontrivial gravitational backgrounds some similar forms as in condensed matter physics. It is shown how quasiperiodic structures determined by general nonlinear, or additive, functionals for generating functions and (effective) sources may transform black hole like configurations into cosmological metrics and inversely. We speculate on possible implications of quasiperiodic solutions in dark energy and dark matter physics. Finally, it is concluded that geometric methods for constructing exact solutions consist an important alternative tool to numerical relativity for investigating nonlinear effects in astrophysics and cosmology.

  3. Towards a framework for testing general relativity with extreme-mass-ratio-inspiral observations

    NASA Astrophysics Data System (ADS)

    Chua, A. J. K.; Hee, S.; Handley, W. J.; Higson, E.; Moore, C. J.; Gair, J. R.; Hobson, M. P.; Lasenby, A. N.

    2018-07-01

    Extreme-mass-ratio-inspiral observations from future space-based gravitational-wave detectors such as LISA will enable strong-field tests of general relativity with unprecedented precision, but at prohibitive computational cost if existing statistical techniques are used. In one such test that is currently employed for LIGO black hole binary mergers, generic deviations from relativity are represented by N deformation parameters in a generalized waveform model; the Bayesian evidence for each of its 2N combinatorial submodels is then combined into a posterior odds ratio for modified gravity over relativity in a null-hypothesis test. We adapt and apply this test to a generalized model for extreme-mass-ratio inspirals constructed on deformed black hole spacetimes, and focus our investigation on how computational efficiency can be increased through an evidence-free method of model selection. This method is akin to the algorithm known as product-space Markov chain Monte Carlo, but uses nested sampling and improved error estimates from a rethreading technique. We perform benchmarking and robustness checks for the method, and find order-of-magnitude computational gains over regular nested sampling in the case of synthetic data generated from the null model.

  4. PM2.5, oxidant defence and cardiorespiratory health: a review.

    PubMed

    Weichenthal, Scott A; Godri-Pollitt, Krystal; Villeneuve, Paul J

    2013-05-04

    Airborne fine particle mass concentrations (PM2.5) are used for ambient air quality management worldwide based in part on known cardiorespiratory health effects. While oxidative stress is generally thought to be an important mechanism in determining these effects, relatively few studies have specifically examined how oxidant defence may impact susceptibility to particulate air pollution. Here we review studies that explore the impact of polymorphisms in anti-oxidant related genes or anti-oxidant supplementation on PM2.5-induced cardiorespiratory outcomes in an effort to summarize existing evidence related to oxidative stress defence and the health effects of PM2.5. Recent studies of PM-oxidative burden were also examined. In total, nine studies were identified and reviewed and existing evidence generally suggests that oxidant defence may modify the impact of PM2.5 exposure on various health outcomes, particularly heart rate variability (a measure of autonomic function) which was the most common outcome examined in the studies reviewed. Few studies examined interactions between PM2.5 and oxidant defence for respiratory outcomes, and in general studies focused primarily on acute health effects. Therefore, further evaluation of the potential modifying role of oxidant defence in PM2.5-induced health effects is required, particularly for chronic outcomes. Similarly, while an exposure metric that captures the ability of PM2.5 to cause oxidative stress may offer advantages over traditional mass concentration measurements, little epidemiological evidence is currently available to evaluate the potential benefits of such an approach. Therefore, further evaluation is required to determine how this metric may be incorporated in ambient air quality management.

  5. Characteristics of Disorder-Related Autobiographical Memory in Acute Anorexia Nervosa Patients.

    PubMed

    Huber, Julia; Salatsch, Carmen; Ingenerf, Katrin; Schmid, Carolin; Maatouk, Imad; Weisbrod, Matthias; Herzog, Wolfgang; Friederich, Hans-Christoph; Nikendei, Christoph

    2015-09-01

    First studies revealed overgeneral autobiographical memories in anorexia nervosa (AN) patients. The aim of the present study was to investigate frequency, generalization and valence of autobiographical memories in AN patients in response to eating disorder-related cue words. Autobiographical memory was examined in 21 AN patients and 21 healthy controls (HC) using a modified version of the Autobiographical Memory Test, incorporating body-related, food-related, perfectionism-related, depression-related and neutral cues. Anorexia nervosa patients recalled fewer and more general autobiographical memories compared with HC. For eating disorder-related cues as against neutral ones, AN patients compared with HC showed fewer memories for food-related and body-related cues, an elevated overgeneralization for food-related cues, while the valence of the retrieved memories was more negative in response to body-related cues. This study detects disorder-related autobiographical memory alterations in AN, which are intensified in response to symptom-related cues. The findings are discussed with regard to their maladaptive function in emotion regulation. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

  6. Beyond δ : Tailoring marked statistics to reveal modified gravity

    NASA Astrophysics Data System (ADS)

    Valogiannis, Georgios; Bean, Rachel

    2018-01-01

    Models that seek to explain cosmic acceleration through modifications to general relativity (GR) evade stringent Solar System constraints through a restoring, screening mechanism. Down-weighting the high-density, screened regions in favor of the low density, unscreened ones offers the potential to enhance the amount of information carried in such modified gravity models. In this work, we assess the performance of a new "marked" transformation and perform a systematic comparison with the clipping and logarithmic transformations, in the context of Λ CDM and the symmetron and f (R ) modified gravity models. Performance is measured in terms of the fractional boost in the Fisher information and the signal-to-noise ratio (SNR) for these models relative to the statistics derived from the standard density distribution. We find that all three statistics provide improved Fisher boosts over the basic density statistics. The model parameters for the marked and clipped transformation that best enhance signals and the Fisher boosts are determined. We also show that the mark is useful both as a Fourier and real-space transformation; a marked correlation function also enhances the SNR relative to the standard correlation function, and can on mildly nonlinear scales show a significant difference between the Λ CDM and the modified gravity models. Our results demonstrate how a series of simple analytical transformations could dramatically increase the predicted information extracted on deviations from GR, from large-scale surveys, and give the prospect for a much more feasible potential detection.

  7. Generalized design of a zero-geometric-loss, astigmatism-free, modified four-objective multipass matrix system.

    PubMed

    Guo, Yin; Sun, LiQun; Yang, Zheng; Liu, Zilong

    2016-02-20

    During this study we constructed a generalized parametric modified four-objective multipass matrix system (MMS). We used an optical system comprising four asymmetrical spherical mirrors to improve the alignment process. The use of a paraxial equation for the design of the front transfer optics yielded the initial condition for modeling our MMS. We performed a ray tracing simulation to calculate the significant aberration of the system (astigmatism). Based on the calculated meridional and sagittal focus positions, the complementary focusing mirror was easily designed to provide an output beam free of astigmatism. We have presented an example of a 108-transit multipass system (5×7 matrix arrangement) with a relatively larger numerical aperture source (xenon light source). The whole system exhibits zero theoretical geometrical loss when simulated with Zemax software. The MMS construction strategy described in this study provides an anastigmatic output beam and the generalized approach to design a controllable matrix spot pattern on the field mirrors. Asymmetrical reflective mirrors aid in aligning the whole system with high efficiency. With the generalized design strategy in terms of optics configuration and asymmetrical fabrication method in this paper, other kinds of multipass matrix system coupled with different sources and detector systems also can be achieved.

  8. General Deficit in Inhibitory Control of Excessive Smartphone Users: Evidence from an Event-Related Potential Study

    PubMed Central

    Chen, Jingwei; Liang, Yunsi; Mai, Chunmiao; Zhong, Xiyun; Qu, Chen

    2016-01-01

    With the popularity of smartphones, the problem of excessive use has drawn increasing attention. However, it is not clear whether there is an inhibitory deficit in excessive smartphone users. Using a modified Go/NoGo task with three types of context (blank, neutral, and smartphone-related), the present study combined measures of behavior and electrophysiology [event-related potentials (ERPs)] to examine general and specific inhibitory control in an excessive smartphone use group and a normal use group. Results showed that participants in both groups had larger amplitude of N2 and P3 on NoGo trials than Go trials. NoGo N2, an ERP component associated with inhibitory control, was more negative in the excessive smartphone use group than the normal use group. These results suggest that in the early stage of inhibition processing, excessive smartphone users experience more conflicts and show a general deficit that does not depend on smartphone-related cues. Moreover, the study provides further neuroscience evidence of the physiological correlates of excessive smartphone use. PMID:27148120

  9. Born-Infeld inspired modifications of gravity

    NASA Astrophysics Data System (ADS)

    Beltrán Jiménez, Jose; Heisenberg, Lavinia; Olmo, Gonzalo J.; Rubiera-Garcia, Diego

    2018-01-01

    General Relativity has shown an outstanding observational success in the scales where it has been directly tested. However, modifications have been intensively explored in the regimes where it seems either incomplete or signals its own limit of validity. In particular, the breakdown of unitarity near the Planck scale strongly suggests that General Relativity needs to be modified at high energies and quantum gravity effects are expected to be important. This is related to the existence of spacetime singularities when the solutions of General Relativity are extrapolated to regimes where curvatures are large. In this sense, Born-Infeld inspired modifications of gravity have shown an extraordinary ability to regularise the gravitational dynamics, leading to non-singular cosmologies and regular black hole spacetimes in a very robust manner and without resorting to quantum gravity effects. This has boosted the interest in these theories in applications to stellar structure, compact objects, inflationary scenarios, cosmological singularities, and black hole and wormhole physics, among others. We review the motivations, various formulations, and main results achieved within these theories, including their observational viability, and provide an overview of current open problems and future research opportunities.

  10. Universal binding energy relation for cleaved and structurally relaxed surfaces.

    PubMed

    Srirangarajan, Aarti; Datta, Aditi; Gandi, Appala Naidu; Ramamurty, U; Waghmare, U V

    2014-02-05

    The universal binding energy relation (UBER), derived earlier to describe the cohesion between two rigid atomic planes, does not accurately capture the cohesive properties when the cleaved surfaces are allowed to relax. We suggest a modified functional form of UBER that is analytical and at the same time accurately models the properties of surfaces relaxed during cleavage. We demonstrate the generality as well as the validity of this modified UBER through first-principles density functional theory calculations of cleavage in a number of crystal systems. Our results show that the total energies of all the relaxed surfaces lie on a single (universal) energy surface, that is given by the proposed functional form which contains an additional length-scale associated with structural relaxation. This functional form could be used in modelling the cohesive zones in crack growth simulation studies. We find that the cohesive law (stress-displacement relation) differs significantly in the case where cracked surfaces are allowed to relax, with lower peak stresses occurring at higher displacements.

  11. New sets of eigenvalues in inverse scattering for inhomogeneous media and their determination from scattering data

    NASA Astrophysics Data System (ADS)

    Audibert, Lorenzo; Cakoni, Fioralba; Haddar, Houssem

    2017-12-01

    In this paper we develop a general mathematical framework to determine interior eigenvalues from a knowledge of the modified far field operator associated with an unknown (anisotropic) inhomogeneity. The modified far field operator is obtained by subtracting from the measured far field operator the computed far field operator corresponding to a well-posed scattering problem depending on one (possibly complex) parameter. Injectivity of this modified far field operator is related to an appropriate eigenvalue problem whose eigenvalues can be determined from the scattering data, and thus can be used to obtain information about material properties of the unknown inhomogeneity. We discuss here two examples of such modification leading to a Steklov eigenvalue problem, and a new type of the transmission eigenvalue problem. We present some numerical examples demonstrating the viability of our method for determining the interior eigenvalues form far field data.

  12. Socio-ecological implications of modifying rotation lengths in forestry.

    PubMed

    Roberge, Jean-Michel; Laudon, Hjalmar; Björkman, Christer; Ranius, Thomas; Sandström, Camilla; Felton, Adam; Sténs, Anna; Nordin, Annika; Granström, Anders; Widemo, Fredrik; Bergh, Johan; Sonesson, Johan; Stenlid, Jan; Lundmark, Tomas

    2016-02-01

    The rotation length is a key component of even-aged forest management systems. Using Fennoscandian forestry as a case, we review the socio-ecological implications of modifying rotation lengths relative to current practice by evaluating effects on a range of ecosystem services and on biodiversity conservation. The effects of shortening rotations on provisioning services are expected to be mostly negative to neutral (e.g. production of wood, bilberries, reindeer forage), while those of extending rotations would be more varied. Shortening rotations may help limit damage by some of today's major damaging agents (e.g. root rot, cambium-feeding insects), but may also increase other damage types (e.g. regeneration pests) and impede climate mitigation. Supporting (water, soil nutrients) and cultural (aesthetics, cultural heritage) ecosystem services would generally be affected negatively by shortened rotations and positively by extended rotations, as would most biodiversity indicators. Several effect modifiers, such as changes to thinning regimes, could alter these patterns.

  13. Looking for empty topological wormhole spacetimes in F(R)-modified gravity

    NASA Astrophysics Data System (ADS)

    Di Criscienzo, R.; Myrzakulov, R.; Sebastiani, L.

    2013-12-01

    Much attention has been recently devoted to modified theories of gravity, the simplest models of which overcome General Relativity simply by replacing R with F(R) in the Einstein-Hilbert action. Unfortunately, such models typically lack most of the beautiful solutions discovered in Einstein’s gravity. Nonetheless, in F(R) gravity, it has been possible to get at least few black holes, but still we do not know any empty wormhole-like spacetime solution. This paper aims to explain why it is so hard to get such solutions (given that they exist!). Few solutions are derived in the simplest cases, while only an implicit form has been obtained in the non-trivial case.

  14. Probing Modified Gravity with Double Pulsars

    NASA Astrophysics Data System (ADS)

    Deng, Xue-Mei; Xie, Yi; Huang, Tian-Yi

    2015-01-01

    Although Einstein's general relativity has passed all the tests so far, alternative theories are still required for deeper understanding of the nature of gravity. Double pulsars provide us a significant opportunity to test them. In order to probe some modified gravities which try to explain some astrophysical phenomena without dark matter, we use periastron advance dot ω of four binary pulsars (PSR B1913+16, PSR B1534+12, PSR J0737-3039 and PSR B2127+11C) to constrain their Yukawa parameters: λ = (3.97 ± 0.01) × 108m and α = (2.40 ± 0.02) × 10-8. It might help us to distinguish different gravity theories and get closer to the new physics.

  15. Coherent light squeezing states within a modified microring system

    NASA Astrophysics Data System (ADS)

    Ali, J.; Pornsuwancharoen, N.; Youplao, P.; Aziz, M. S.; Amiri, I. S.; Chaiwong, K.; Chiangga, S.; Singh, G.; Yupapin, P.

    2018-06-01

    We have proposed the simple method of the squeezed light generation in the modified microring resonator, which is known as the microring conjugate mirror (MCM). When the monochromatic light is input into the MCM, the general form of the squeezed coherent states for a quantum harmonic oscillator can be generated by controlling the additional two side rings, which are the phase modulators. By using the graphical method called the Optiwave program, the coherent squeezed states of coherent light within an MCM can be obtained and interpreted as the amplitude, phase, quadrature and photon number-squeezed states. This method has shown potentials for microring related device design, which can be used before practical applications.

  16. On Gauge Invariant Cosmological Perturbations in UV-modified Hořava Gravity: A Brief Introduction

    NASA Astrophysics Data System (ADS)

    Park, Mu-In

    2018-01-01

    We revisit gauge invariant cosmological perturbations in UV-modified, z = 3 Hořava gravity with one scalar matter field, which has been proposed as a renormalizable gravity theory without the ghost problem in four dimensions. We confirm that there is no extra graviton modes and general relativity is recovered in IR, which achieves the consistency of the model. From the UV-modification terms which break the detailed balance condition in UV, we obtain scale-invariant power spectrums for non-inflationary backgrounds, like the power-law expansions, without knowing the details of early expansion history of Universe. This could provide a new framework for the Big Bang cosmology.

  17. Psychological Factors Associated with Chronic Migraine and Severe Migraine-Related Disability: an Observational Study in a Tertiary Headache Center

    PubMed Central

    Seng, Elizabeth K.; Buse, Dawn C.; Klepper, Jaclyn E.; Mayson, Sarah Jo; Grinberg, Amy S.; Grosberg, Brian M.; Pavlovic, Jelena M.; Robbins, Matthew S.; Vollbracht, Sarah E.; Lipton, Richard B.

    2016-01-01

    Objective To evaluate relationships among modifiable psychological factors and chronic migraine and severe migraine-related disability in a clinic-based sample of persons with migraine. Background Evidence evaluating relationships between modifiable psychological factors and chronic migraine and severe migraine-related disability is lacking in people with migraine presenting for routine clinical care. Methods Adults with migraine completed surveys during routinely scheduled visits to a tertiary headache center. Participants completed surveys assessing chronic migraine (meeting criteria for migraine with ≥15 headache days in the past month), severe migraine disability (Migraine Disability Assessment Scale score ≥ 21), and modifiable psychological factors [depressive symptoms (Patient Health Questionnaire-9), anxious symptoms (Generalized Anxiety Disorder-7), Pain Catastrophizing Scale and Headache Specific Locus of Control]. Logistic regression evaluated relationships between modifiable psychological factors and chronic migraine and severe migraine disability. Results Among 90 eligible participants the mean age was 45.0 (SD = 12.4); 84.8% were women. One-third (36.0%) met study criteria for chronic migraine; half of participants (51.5%) reported severe migraine-related disability. Higher depressive symptoms (OR = 1.99, 95% CI = 1,11, 3.55) and chance HSLC (OR = 1.85, 95% CI = 1.13, 1.43) were associated with chronic migraine. Higher depressive symptoms (OR = 3.54, 95%CI = 1.49, 8.41), anxiety symptoms (OR = 3.65, 95% CI = 1.65, 8.06), and pain catastrophizing (OR = 1.95, 95% CI = 1.14, 3.35), were associated with severe migraine-related disability. Conclusions Psychiatric symptoms and pain catastrophizing were strongly associated with severe migraine-related disability. Depression and chance locus of control were associated with chronic migraine. This study supports the need for longitudinal observational studies to evaluate relationships among naturalistic variation in psychological factors, migraine-related disability and migraine chronification. PMID:28139000

  18. Affine connection form of Regge calculus

    NASA Astrophysics Data System (ADS)

    Khatsymovsky, V. M.

    2016-12-01

    Regge action is represented analogously to how the Palatini action for general relativity (GR) as some functional of the metric and a general connection as independent variables represents the Einstein-Hilbert action. The piecewise flat (or simplicial) spacetime of Regge calculus is equipped with some world coordinates and some piecewise affine metric which is completely defined by the set of edge lengths and the world coordinates of the vertices. The conjugate variables are the general nondegenerate matrices on the three-simplices which play the role of a general discrete connection. Our previous result on some representation of the Regge calculus action in terms of the local Euclidean (Minkowsky) frame vectors and orthogonal connection matrices as independent variables is somewhat modified for the considered case of the general linear group GL(4, R) of the connection matrices. As a result, we have some action invariant w.r.t. arbitrary change of coordinates of the vertices (and related GL(4, R) transformations in the four-simplices). Excluding GL(4, R) connection from this action via the equations of motion we have exactly the Regge action for the considered spacetime.

  19. Generalization of a Modified Food Preference.

    ERIC Educational Resources Information Center

    Birch, Leann Lipps

    1981-01-01

    Assesses preschool children's preferences for eight snack foods and tests procedures to modify preferences for certain foods by having children sort foods according to self-determined categories. Enhanced preferences for target foods generalized to other foods in the same category only for children using semantic sorting categories. (Author/DB)

  20. 26 CFR 1.954-8 - Foreign base company oil related income.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... generally under the principles of §§ 1.861-1 to 1.863-5. See § 1.863-6. Thus, income from the performance of... section 832(a) and as modified by the principles of § 1.953-4 (other than as the section is applied to... that country and will apply regardless of the country of sale of the primary product. (2) Marketing...

  1. The Influence of Task Dynamics on Inductive Generalizations: How Sequential and Simultaneous Presentation of Evidence Impacts the Strength and Scope of Property Projections

    ERIC Educational Resources Information Center

    Lawson, Chris A.

    2017-01-01

    Young children are remarkably flexible reasoners insofar as they modify their inferences to accommodate the conceptual information or perceptual relations represented in an inductive problem. Children's inductive reasoning is highly sensitive to what evidence is presented to them. Four experiments with 115 preschoolers (M[subscript age] = 4;8) and…

  2. Questioning the preparatory function of counterfactual thinking.

    PubMed

    Mercier, Hugo; Rolison, Jonathan J; Stragà, Marta; Ferrante, Donatella; Walsh, Clare R; Girotto, Vittorio

    2017-02-01

    Why do individuals mentally modify reality (e.g., "If it hadn't rained, we would have won the game")? According to the dominant view, counterfactuals primarily serve to prepare future performance. In fact, individuals who have just failed a task tend to modify the uncontrollable features of their attempt (e.g., "If the rules of the game were different, I would have won it"), generating counterfactuals that are unlikely to play any preparatory role. By contrast, they generate prefactuals that focus on the controllable features of their ensuing behavior (e.g., "If I concentrate more, I will win the next game"). Here, we test whether this tendency is robust and general. Studies 1a and 1b replicate this tendency and show that it occurs regardless of whether individuals think about their failures or their successes. Study 2 shows that individuals generate relatively few controllable counterfactuals, unless explicitly prompted to do so. These results raise some questions regarding the generality of the dominant view according to which counterfactuals mainly serve a preparatory function.

  3. Gender-related stress among Japanese working women.

    PubMed

    Ogiwara, Chikako; Tsuda, Hitoshi; Akiyama, Tsuyoshi; Sakai, Yoshie

    2008-09-01

    This article addresses gender-related stresses of working women in Japan. We conducted a study of 399 employees in Japan using the National Institute for Occupational Safety and Health General Job Stress questionnaire. The results suggest that for women the most significant factor related to depression is interpersonal conflict, whereas for men, it is professional matters. In addition, we conducted interviews with Japanese female employees about their occupational stress. Our interviews indicated that for the occupational mental health of working women, the establishment of modified and supportive interpersonal relations within workplace environments may be required because of the gender roles expected of women in a male-dominant socioculture.

  4. Corrected black hole thermodynamics in Damour-Ruffini’s method with generalized uncertainty principle

    NASA Astrophysics Data System (ADS)

    Zhou, Shiwei; Chen, Ge-Rui

    Recently, some approaches to quantum gravity indicate that a minimal measurable length lp ˜ 10-35 should be considered, a direct implication of the minimal measurable length is the generalized uncertainty principle (GUP). Taking the effect of GUP into account, Hawking radiation of massless scalar particles from a Schwarzschild black hole is investigated by the use of Damour-Ruffini’s method. The original Klein-Gordon equation is modified. It is obtained that the corrected Hawking temperature is related to the energy of emitting particles. Some discussions appear in the last section.

  5. Simple solutions for relativistic generalizations of the Child-Langmuir law and the Langmuir-Blodgett law

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang Yongpeng; Northwest Institute of Nuclear Technology, P.O. Box 69-13, Xi'an 710024; Liu Guozhi

    In this paper, the Child-Langmuir law and Langmuir-Blodgett law are generalized to the relativistic regime by a simple method. Two classical laws suitable for the nonrelativistic regime are modified to simple approximate expressions applicable for calculating the space-charge-limited currents of one-dimensional steady-state planar diodes and coaxial diodes under the relativistic regime. The simple approximate expressions, extending the Child-Langmuir law and Langmuir-Blodgett law to fit the full range of voltage, have small relative errors less than 1% for one-dimensional planar diodes and less than 5% for coaxial diodes.

  6. Planck constant as spectral parameter in integrable systems and KZB equations

    NASA Astrophysics Data System (ADS)

    Levin, A.; Olshanetsky, M.; Zotov, A.

    2014-10-01

    We construct special rational gl N Knizhnik-Zamolodchikov-Bernard (KZB) equations with Ñ punctures by deformation of the corresponding quantum gl N rational R-matrix. They have two parameters. The limit of the first one brings the model to the ordinary rational KZ equation. Another one is τ. At the level of classical mechanics the deformation parameter τ allows to extend the previously obtained modified Gaudin models to the modified Schlesinger systems. Next, we notice that the identities underlying generic (elliptic) KZB equations follow from some additional relations for the properly normalized R-matrices. The relations are noncommutative analogues of identities for (scalar) elliptic functions. The simplest one is the unitarity condition. The quadratic (in R matrices) relations are generated by noncommutative Fay identities. In particular, one can derive the quantum Yang-Baxter equations from the Fay identities. The cubic relations provide identities for the KZB equations as well as quadratic relations for the classical r-matrices which can be treated as halves of the classical Yang-Baxter equation. At last we discuss the R-matrix valued linear problems which provide gl Ñ CM models and Painlevé equations via the above mentioned identities. The role of the spectral parameter plays the Planck constant of the quantum R-matrix. When the quantum gl N R-matrix is scalar ( N = 1) the linear problem reproduces the Krichever's ansatz for the Lax matrices with spectral parameter for the gl Ñ CM models. The linear problems for the quantum CM models generalize the KZ equations in the same way as the Lax pairs with spectral parameter generalize those without it.

  7. Lipids and lipid changes with synthetic and biologic disease-modifying antirheumatic drug therapy in rheumatoid arthritis: implications for cardiovascular risk.

    PubMed

    Myasoedova, Elena

    2017-05-01

    To highlight recently published studies addressing lipid changes with disease-modifying antirheumatic drug use and outline implications on cardiovascular outcomes in rheumatoid arthritis (RA). Growing evidence suggests lower lipid levels are present in patients with active RA vs. general population, and significant modifications of lipid profile with inflammation suppression. Increase in lipid levels in patients with RA on synthetic and biological disease-modifying antirheumatic drugs may be accompanied by antiatherogenic changes in lipid composition and function. The impact of lipid changes on cardiovascular outcomes in RA is a subject of active research. The role of lipids in cardiovascular risk in RA may be overpowered by the benefits of inflammation suppression with antirheumatic medication use. Recommendations on lipid management in RA are evolving but uncertainty exists regarding frequency of lipid testing and goals of treatment. Knowledge about quantitative and qualitative lipid changes in RA is expanding. The relative role of lipids in cardiovascular risk in the context of systemic inflammation and antirheumatic therapy remains uncertain, delaying development of effective strategies for cardiovascular risk management in RA. Studies are underway to address these knowledge gaps and may be expected to inform cardiovascular risk management in RA and the general population.

  8. Cardio-respiratory outcomes associated with exposure to wildfire smoke are modified by measures of community health

    PubMed Central

    2012-01-01

    Background Characterizing factors which determine susceptibility to air pollution is an important step in understanding the distribution of risk in a population and is critical for setting appropriate policies. We evaluate general and specific measures of community health as modifiers of risk for asthma and congestive heart failure following an episode of acute exposure to wildfire smoke. Methods A population-based study of emergency department visits and daily concentrations of fine particulate matter during a wildfire in North Carolina was performed. Determinants of community health defined by County Health Rankings were evaluated as modifiers of the relative risk. A total of 40 mostly rural counties were included in the study. These rankings measure factors influencing health: health behaviors, access and quality of clinical care, social and economic factors, and physical environment, as well as, the outcomes of health: premature mortality and morbidity. Pollutant concentrations were obtained from a mathematically modeled smoke forecasting system. Estimates of relative risk for emergency department visits were based on Poisson mixed effects regression models applied to daily visit counts. Results For asthma, the strongest association was observed at lag day 0 with excess relative risk of 66%(28,117). For congestive heart failure the excess relative risk was 42%(5,93). The largest difference in risk was observed after stratifying on the basis of Socio-Economic Factors. Difference in risk between bottom and top ranked counties by Socio-Economic Factors was 85% and 124% for asthma and congestive heart failure respectively. Conclusions The results indicate that Socio-Economic Factors should be considered as modifying risk factors in air pollution studies and be evaluated in the assessment of air pollution impacts. PMID:23006928

  9. Cardio-respiratory outcomes associated with exposure to wildfire smoke are modified by measures of community health.

    PubMed

    Rappold, Ana G; Cascio, Wayne E; Kilaru, Vasu J; Stone, Susan L; Neas, Lucas M; Devlin, Robert B; Diaz-Sanchez, David

    2012-09-24

    Characterizing factors which determine susceptibility to air pollution is an important step in understanding the distribution of risk in a population and is critical for setting appropriate policies. We evaluate general and specific measures of community health as modifiers of risk for asthma and congestive heart failure following an episode of acute exposure to wildfire smoke. A population-based study of emergency department visits and daily concentrations of fine particulate matter during a wildfire in North Carolina was performed. Determinants of community health defined by County Health Rankings were evaluated as modifiers of the relative risk. A total of 40 mostly rural counties were included in the study. These rankings measure factors influencing health: health behaviors, access and quality of clinical care, social and economic factors, and physical environment, as well as, the outcomes of health: premature mortality and morbidity. Pollutant concentrations were obtained from a mathematically modeled smoke forecasting system. Estimates of relative risk for emergency department visits were based on Poisson mixed effects regression models applied to daily visit counts. For asthma, the strongest association was observed at lag day 0 with excess relative risk of 66% (28,117). For congestive heart failure the excess relative risk was 42% (5,93). The largest difference in risk was observed after stratifying on the basis of Socio-Economic Factors. Difference in risk between bottom and top ranked counties by Socio-Economic Factors was 85% and 124% for asthma and congestive heart failure respectively. The results indicate that Socio-Economic Factors should be considered as modifying risk factors in air pollution studies and be evaluated in the assessment of air pollution impacts.

  10. Using Rasch-models to compare the 30-, 20-, and 12-items version of the general health questionnaire taking four recoding schemes into account.

    PubMed

    Alexandrowicz, Rainer W; Friedrich, Fabian; Jahn, Rebecca; Soulier, Nathalie

    2015-01-01

    The present study compares the 30-, 20-, and 12-items versions of the General Health Questionnaire (GHQ) in the original coding and four different recoding schemes (Bimodal, Chronic, Modified Likert and a newly proposed Modified Chronic) with respect to their psychometric qualities. The dichotomized versions (i.e. Bimodal, Chronic and Modified Chronic) were evaluated with the Rasch-Model and the polytomous original version and the Modified Likert version were evaluated with the Partial Credit Model. In general, the versions under consideration showed agreement with the model assumption. However, the recoded versions exhibited some deficits with respect to the Outfit index. Because of the item deficits and for theoretical reasons we argue in favor of using the any of the three length versions with the original four-categorical coding scheme. Nevertheless, any of the versions appears apt for clinical use from a psychometric perspective.

  11. Modifiable worker risk factors contributing to workplace absence: a stakeholder-centred best-evidence synthesis of systematic reviews.

    PubMed

    Wagner, Shannon; White, Marc; Schultz, Izabela; Murray, Eleanor; Bradley, Susan M; Hsu, Vernita; McGuire, Lisa; Schulz, Werner

    2014-01-01

    A challenge facing stakeholders is the identification and translation of relevant high quality research to inform policy and practice. This study engaged academic and community stakeholders in conducting a best evidence-synthesis to identify modifiable risk and protective worker factors across health conditions impacting work-related absence. To identify modifiable worker disability risk and protective factors across common health conditions impacting work-related absence. We searched Medline, Embase, CINHAL, The Cochrane Library, PsycINFO, BusinessSourceComplete, and ABI/Inform from 2000 to 2011. Quantitative, qualitative, or mixed methods systematic reviews of work-focused population were considered for inclusion. Two or more reviewers independently reviewed articles for inclusion and methodological screening. The search strategy, expert input and grey literature identified 2,467 unique records. One hundred and forty-two full text articles underwent comprehensive review. Twenty-four systematic reviews met eligibility criteria. Modifiable worker factors found to have consistent evidence across two or more health conditions included emotional distress, negative enduring psychology/personality factors, negative health and disability perception, decreased physical activity, lack of family support, poor general health, increased functional disability, increased pain, increased fatigue and lack of motivation to return to work. Systematic reviews are limited by availability of high quality studies, lack of consistency of methodological screening and reporting, and variability of outcome measures used.

  12. MS overline -on-shell quark mass relation up to four loops in QCD and a general SU (N ) gauge group

    NASA Astrophysics Data System (ADS)

    Marquard, Peter; Smirnov, Alexander V.; Smirnov, Vladimir A.; Steinhauser, Matthias; Wellmann, David

    2016-10-01

    We compute the relation between heavy quark masses defined in the modified minimal subtraction and the on-shell schemes. Detailed results are presented for all coefficients of the SU (Nc) color factors. The reduction of the four-loop on-shell integrals is performed for a general QCD gauge parameter. Altogether there are about 380 master integrals. Some of them are computed analytically, others with high numerical precision using Mellin-Barnes representations, and the rest numerically with the help of FIESTA. We discuss in detail the precise numerical evaluation of the four-loop master integrals. Updated relations between various short-distance masses and the MS ¯ quark mass to next-to-next-to-next-to-leading order accuracy are provided for the charm, bottom and top quarks. We discuss the dependence on the renormalization and factorization scale.

  13. Social safety, self-rated general health and physical activity: changes in area crime, area safety feelings and the role of social cohesion.

    PubMed

    Ruijsbroek, Annemarie; Droomers, Mariël; Groenewegen, Peter P; Hardyns, Wim; Stronks, Karien

    2015-01-01

    The aim of this study was to examine whether changes over time in reported area crime and perceived area safety were related to self-rated general health and physical activity (PA), in order to provide support for a causal relationship between social safety and health. Additionally, we investigated whether social cohesion protects the residents against the negative impact of unsafe areas on health and PA. Multilevel logistic regression analyses were performed on Dutch survey data, including 47,926 respondents living in 2974 areas. An increase in area level unsafety feelings between 2009 and 2011 was associated with more people reporting poor general health in 2012 in that area, but was not related to PA. Changes in reported area crime were not related to either poor general health or PA. The social cohesion in the area did not modify the effect of changes in social safety on health and PA. The results suggest that tackling feelings of unsafety in an area might contribute to the better general health of the residents. Because changes in area social safety were not associated with PA, we found no leads that such health benefits were achieved through an increase in physical activity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. A review of the generalized uncertainty principle.

    PubMed

    Tawfik, Abdel Nasser; Diab, Abdel Magied

    2015-12-01

    Based on string theory, black hole physics, doubly special relativity and some 'thought' experiments, minimal distance and/or maximum momentum are proposed. As alternatives to the generalized uncertainty principle (GUP), the modified dispersion relation, the space noncommutativity, the Lorentz invariance violation, and the quantum-gravity-induced birefringence effects are summarized. The origin of minimal measurable quantities and the different GUP approaches are reviewed and the corresponding observations are analysed. Bounds on the GUP parameter are discussed and implemented in the understanding of recent PLANCK observations of cosmic inflation. The higher-order GUP approaches predict minimal length uncertainty with and without maximum momenta. Possible arguments against the GUP are discussed; for instance, the concern about its compatibility with the equivalence principles, the universality of gravitational redshift and the free fall and law of reciprocal action are addressed.

  15. A Bootstrap Generalization of Modified Parallel Analysis for IRT Dimensionality Assessment

    ERIC Educational Resources Information Center

    Finch, Holmes; Monahan, Patrick

    2008-01-01

    This article introduces a bootstrap generalization to the Modified Parallel Analysis (MPA) method of test dimensionality assessment using factor analysis. This methodology, based on the use of Marginal Maximum Likelihood nonlinear factor analysis, provides for the calculation of a test statistic based on a parametric bootstrap using the MPA…

  16. Psychobiological Protective Factors Modifying the Association Between Age and Sexual Health in Men: Findings From the Men’s Health 40+ Study

    PubMed Central

    Walther, Andreas; Mahler, Fiona; Debelak, Rudolf; Ehlert, Ulrike

    2017-01-01

    Sexual health severely decreases with age. For males older than 40 years, erectile dysfunction (ED) is the most common sexual disorder. Although physical and psychological risk factors for ED have been identified, protective factors are yet to be determined. To date, no study has examined endocrine and psychosocial factors in parallel with regard to their modifying effect on the age-related increase in ED. Two hundred and seventy-one self-reporting healthy men aged between 40 and 75 years provided both psychometric data on sexual function and a set of potential psychosocial protective factors, and saliva samples for the analysis of steroid hormones and proinflammatory cytokines. Around 35% of the participants reported at least a mild form of ED. Direct associations with ED were identified for perceived general health, emotional support, relationship quality, intimacy motivation but not for steroid hormones or proinflammatory markers. Moderation analyses for the association between age and ED revealed positive effects for testosterone (T), dehydroepiandrosterone (DHEA), perceived general health, emotional support, intimacy motivation, and a negative effect for interleukin-6 (all p < .05; f2 > .17). Group differences between older men with and without ED emerged for T, DHEA, and psychometric measures such as perceived general health, emotional support, satisfaction with life, and intimacy motivation (all p < .05; d > .3). Both psychosocial and endocrine parameters moderated the association between age and sexual health. Perceived general health, emotional support, intimacy motivation, and relationship quality emerged as psychosocial protective factors against ED. Higher T and DHEA and lower interleukin-6 levels also buffered against an age-related increase in ED. PMID:28413941

  17. Minimally modified theories of gravity: a playground for testing the uniqueness of general relativity

    NASA Astrophysics Data System (ADS)

    Carballo-Rubio, Ra{úl; Di Filippo, Francesco; Liberati, Stefano

    2018-06-01

    In a recent paper [1], it was introduced a new class of gravitational theories with two local degrees of freedom. The existence of these theories apparently challenges the distinctive role of general relativity as the unique non-linear theory of massless spin-2 particles. Here we perform a comprehensive analysis of these theories with the aim of (i) understanding whether or not these are actually equivalent to general relativity, and (ii) finding the root of the variance in case these are not. We have found that a broad set of seemingly different theories actually pass all the possible tests of equivalence to general relativity (in vacuum) that we were able to devise, including the analysis of scattering amplitudes using on-shell techniques. These results are complemented with the observation that the only examples which are manifestly not equivalent to general relativity either do not contain gravitons in their spectrum, or are not guaranteed to include only two local degrees of freedom once radiative corrections are taken into account. Coupling to matter is also considered: we show that coupling these theories to matter in a consistent way is not as straightforward as one could expect. Minimal coupling, as well as the most straightforward non-minimal couplings, cannot be used. Therefore, before being able to address any issues in the presence of matter, it would be necessary to find a consistent (and in any case rather peculiar) coupling scheme.

  18. Modifications to the Water Vapor Continuum in the Microwave Suggested by Ground-Based 150-GHz Observations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Turner, D. D.; Cadeddu, M. P.; Lohnert, U.

    2009-10-01

    Abstract—Ground-based observations from two different radiometers are used to evaluate commonly used microwave/ millimeter-wave propagation models at 150 GHz. This frequency has strong sensitivity to changes in precipitable water vapor (PWV) and cloud liquid water. The observations were collected near Hesselbach, Germany, as part of the Atmospheric Radiation Measurement program’s support of the General Observing Period and the Convective and Orographic Precipitation Study. The observations from the two radiometers agree well with each other, with a slope of 0.993 and a mean bias of 0.12 K. The observations demonstrate that the relative sensitivity of the different absorption models to PWVmore » in clear-sky conditions at 150 GHz is significant and that four models differ significantly from the observed brightness temperature. These models were modified to get agreement with the 150-GHz observations, where the PWV ranged from 0.35 to 2.88 cm. The models were modified by adjusting the strength of the foreign- and self-broadened water vapor continuum coefficients, where the magnitude was model dependent. In all cases, the adjustment to the two components of the water vapor continuum was in opposite directions (i.e., increasing the contribution from the foreign-broadened component while decreasing contribution from the self-broadened component or vice versa). While the original models had significant disagreements relative to each other, the resulting modified models show much better agreement relative to each other throughout the microwave spectrum. The modified models were evaluated using independent observations at 31.4 GHz.« less

  19. Why do children think they get discomfort related to daily activities?

    PubMed

    Coleman, Jemma; Straker, Leon; Ciccarelli, Marina

    2009-01-01

    Children commonly report musculoskeletal discomfort related to different activities such as computer use, playing electronic games, watching TV, reading, and performing physical and hand intensive activities. Discomfort can result in disability and is a strong predictor of future discomfort in adulthood. Adult beliefs regarding discomfort can affect the level of disability and are modifiable. Children's beliefs regarding discomfort could potentially be modified to minimise disability related to musculoskeletal disorders. The aim of this study was to describe children's beliefs about why they experience musculoskeletal discomfort, both in general and related to specific activities. Eighty eight school children completed questionnaires on frequency and usual duration of nine activities, whether they had felt discomfort and what they believed was the cause of any discomfort in relation to those activities. The most common activity was TV watching, and most activities were performed for 1 hour or shorter. Bad posture and doing too much of a certain activity were the most common beliefs regarding reasons for discomfort. This study shows that children are developing beliefs that tend to reflect scientific knowledge about risk factors. These beliefs could be incorporated into preventative health interventions.

  20. Is the firewall consistent? Gedanken experiments on black hole complementarity and firewall proposal

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hwang, Dong-il; Lee, Bum-Hoon; Yeom, Dong-han, E-mail: dongil.j.hwang@gmail.com, E-mail: bhl@sogang.ac.kr, E-mail: innocent.yeom@gmail.com

    2013-01-01

    In this paper, we discuss the black hole complementarity and the firewall proposal at length. Black hole complementarity is inevitable if we assume the following five things: unitarity, entropy-area formula, existence of an information observer, semi-classical quantum field theory for an asymptotic observer, and the general relativity for an in-falling observer. However, large N rescaling and the AMPS argument show that black hole complementarity is inconsistent. To salvage the basic philosophy of the black hole complementarity, AMPS introduced a firewall around the horizon. According to large N rescaling, the firewall should be located close to the apparent horizon. We investigatemore » the consistency of the firewall with the two critical conditions: the firewall should be near the time-like apparent horizon and it should not affect the future infinity. Concerning this, we have introduced a gravitational collapse with a false vacuum lump which can generate a spacetime structure with disconnected apparent horizons. This reveals a situation that there is a firewall outside of the event horizon, while the apparent horizon is absent. Therefore, the firewall, if it exists, not only does modify the general relativity for an in-falling observer, but also modify the semi-classical quantum field theory for an asymptotic observer.« less

  1. Linearization instability for generic gravity in AdS spacetime

    NASA Astrophysics Data System (ADS)

    Altas, Emel; Tekin, Bayram

    2018-01-01

    In general relativity, perturbation theory about a background solution fails if the background spacetime has a Killing symmetry and a compact spacelike Cauchy surface. This failure, dubbed as linearization instability, shows itself as non-integrability of the perturbative infinitesimal deformation to a finite deformation of the background. Namely, the linearized field equations have spurious solutions which cannot be obtained from the linearization of exact solutions. In practice, one can show the failure of the linear perturbation theory by showing that a certain quadratic (integral) constraint on the linearized solutions is not satisfied. For non-compact Cauchy surfaces, the situation is different and for example, Minkowski space having a non-compact Cauchy surface, is linearization stable. Here we study, the linearization instability in generic metric theories of gravity where Einstein's theory is modified with additional curvature terms. We show that, unlike the case of general relativity, for modified theories even in the non-compact Cauchy surface cases, there are some theories which show linearization instability about their anti-de Sitter backgrounds. Recent D dimensional critical and three dimensional chiral gravity theories are two such examples. This observation sheds light on the paradoxical behavior of vanishing conserved charges (mass, angular momenta) for non-vacuum solutions, such as black holes, in these theories.

  2. Is the firewall consistent? Gedanken experiments on black hole complementarity and firewall proposal

    NASA Astrophysics Data System (ADS)

    Hwang, Dong-il; Lee, Bum-Hoon; Yeom, Dong-han

    2013-01-01

    In this paper, we discuss the black hole complementarity and the firewall proposal at length. Black hole complementarity is inevitable if we assume the following five things: unitarity, entropy-area formula, existence of an information observer, semi-classical quantum field theory for an asymptotic observer, and the general relativity for an in-falling observer. However, large N rescaling and the AMPS argument show that black hole complementarity is inconsistent. To salvage the basic philosophy of the black hole complementarity, AMPS introduced a firewall around the horizon. According to large N rescaling, the firewall should be located close to the apparent horizon. We investigate the consistency of the firewall with the two critical conditions: the firewall should be near the time-like apparent horizon and it should not affect the future infinity. Concerning this, we have introduced a gravitational collapse with a false vacuum lump which can generate a spacetime structure with disconnected apparent horizons. This reveals a situation that there is a firewall outside of the event horizon, while the apparent horizon is absent. Therefore, the firewall, if it exists, not only does modify the general relativity for an in-falling observer, but also modify the semi-classical quantum field theory for an asymptotic observer.

  3. The generalized second law of thermodynamics in Hořava-Lifshitz cosmology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jamil, Mubasher; Saridakis, Emmanuel N.; Setare, M.R., E-mail: mjamil@camp.nust.edu.pk, E-mail: msaridak@phys.uoa.gr, E-mail: rezakord@ipm.ir

    2010-11-01

    We investigate the validity of the generalized second law of thermodynamics in a universe governed by Hořava-Lifshitz gravity. Under the equilibrium assumption, that is in the late-time cosmological regime, we calculate separately the entropy time-variation for the matter fluid and, using the modified entropy relation, that of the apparent horizon itself. We find that under detailed balance the generalized second law is generally valid for flat and closed geometry and it is conditionally valid for an open universe, while beyond detailed balance it is only conditionally valid for all curvatures. Furthermore, we also follow the effective approach showing that itmore » can lead to misleading results. The non-complete validity of the generalized second law could either provide a suggestion for its different application, or act as an additional problematic feature of Hořava-Lifshitz gravity.« less

  4. Antigravity Acts on Photons

    NASA Astrophysics Data System (ADS)

    Brynjolfsson, Ari

    2002-04-01

    Einstein's general theory of relativity assumes that photons don't change frequency as they move from Sun to Earth. This assumption is correct in classical physics. All experiments proving the general relativity are in the domain of classical physics. This include the tests by Pound et al. of the gravitational redshift of 14.4 keV photons; the rocket experiments by Vessot et al.; the Galileo solar redshift experiments by Krisher et al.; the gravitational deflection of light experiments by Riveros and Vucetich; and delay of echoes of radar signals passing close to Sun as observed by Shapiro et al. Bohr's correspondence principle assures that quantum mechanical theory of general relativity agrees with Einstein's classical theory when frequency and gravitational field gradient approach zero, or when photons cannot interact with the gravitational field. When we treat photons as quantum mechanical particles; we find that gravitational force on photons is reversed (antigravity). This modified theory contradicts the equivalence principle, but is consistent with all experiments. Solar lines and distant stars are redshifted in accordance with author's plasma redshift theory. These changes result in a beautiful consistent cosmology.

  5. Heating up relations between cold fish: competition modifies responses to climate change.

    PubMed

    Urban, Mark C; Holt, Robert D; Gilman, Sarah E; Tewksbury, Joshua

    2011-05-01

    Most predictions about species responses to climate change ignore species interactions. Helland and colleagues (2011) test whether this assumption is valid by evaluating whether ice cover affects competition between brown trout [Salmo trutta (L.)] and Arctic charr [Salvelinus alpines (L.)]. They show that increasing ice cover correlates with lower trout biomass when Arctic charr co-occur, but not in charr's absence. In experiments, charr grew better in the cold, dark environments that typify ice-covered lakes. Decreasing ice cover with warmer winters could mean more trout and fewer charr. More generally, their results provide an excellent example, suggesting that species interactions can strongly modify responses to climate change. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

  6. Finsler-type modification of the Coulomb law

    NASA Astrophysics Data System (ADS)

    Itin, Yakov; Lämmerzahl, Claus; Perlick, Volker

    2014-12-01

    Finsler geometry is a natural generalization of pseudo-Riemannian geometry. It can be motivated e.g. by a modified version of the Ehlers-Pirani-Schild axiomatic approach to space-time theory. Also, some scenarios of quantum gravity suggest a modified dispersion relation which could be phrased in terms of Finsler geometry. On a Finslerian space-time, the universality of free fall is still satisfied but local Lorentz invariance is violated in a way not covered by standard Lorentz invariance violation schemes. In this paper we consider a Finslerian modification of Maxwell's equations. The corrections to the Coulomb potential and to the hydrogen energy levels are computed. We find that the Finsler metric corrections yield a splitting of the energy levels. Experimental data provide bounds for the Finsler parameters.

  7. Towards thermodynamics of universal horizons in Einstein-æther theory.

    PubMed

    Berglund, Per; Bhattacharyya, Jishnu; Mattingly, David

    2013-02-15

    Holography grew out of black hole thermodynamics, which relies on the causal structure and general covariance of general relativity. In Einstein-æther theory, a generally covariant theory with a dynamical timelike unit vector, every solution breaks local Lorentz invariance, thereby grossly modifying the causal structure of gravity. However, there are still absolute causal boundaries, called "universal horizons," which are not Killing horizons yet obey a first law of black hole mechanics and must have an entropy if they do not violate a generalized second law. We couple a scalar field to the timelike vector and show via the tunneling approach that the universal horizon radiates as a blackbody at a fixed temperature, even if the scalar field equations also violate local Lorentz invariance. This suggests that the class of holographic theories may be much broader than currently assumed.

  8. The Fock-Schwinger gauge in the BFV formalism

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Barcelos-Neto, J.; Galvao, C.A.P.; Gaete, P.

    1991-06-07

    The authors consider the implementation of a properly modified form of the Fock-Schwinger gauge condition in a general non-Abelian gauge theory in the context of the BFV formalism. In this paper arguments are presented to justify the necessity of modifying the original Fock-Schwinger condition. The free field propagator and the general Ward identity are also calculated.

  9. FNF Construction Inc. Window Rock Airport Project: Coverage Under General Air Quality Permit for New or Modified Minor Source Cement Batch Plants in Indian Country

    EPA Pesticide Factsheets

    Approved Request for Coverage under General Air Quality Permit for New or Modified Minor Source Cement Batch Plants in Indian Country for FNF Construction Inc. Window Rock Airport Soil Cement Mixing Plant Project, Beacon Road, Window Rock, Arizona 86515.

  10. Common attributes of high/low performing general surgery programs as they relate to QE/CE pass rates.

    PubMed

    Bankhead-Kendall, Brittany; Slama, Eliza; Truitt, Michael S

    2016-12-01

    This comparative study aims to identify the differences between high and low performing programs as defined by their ABS board pass rates. We identified programs in the top 5% (TP) and lower 5% (LP) for 1st time QE/CE pass rates during the study period with resident and program related variables. All data was pooled and analyzed. TP had more U.S. graduates, higher average USMLE Step 1/2 scores, and all residents took the exam within a year of graduation. TP were more likely to rotate at a Level 1 trauma center, spent more time with simulation, and had numerous fellowship programs. They ascribed their success to mock oral exams, mature curricula, and group educational activities. Graduates of TP chose general surgery twice as often (40% vs 19%). Program related factors (Level 1 trauma, excellent didactics, higher number of fellowships, increased group educational activities, higher percentage of graduates into general surgery) are associated with TP. Our data suggests there may be modifiable program related variables that positively impact QE/CE pass rates. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Production and stability of mechanochemically exfoliated graphene in water and culture media

    NASA Astrophysics Data System (ADS)

    León, V.; González-Domínguez, J. M.; Fierro, J. L. G.; Prato, M.; Vázquez, E.

    2016-07-01

    The preparation of graphene suspensions in water, without detergents or any other additives is achieved using freeze-dried graphene powders, produced by mechanochemical exfoliation of graphite. These powders of graphene can be safely stored or shipped, and promptly dissolved in aqueous media. The suspensions are relatively stable in terms of time, with a maximum loss of ~25% of the initial concentration at 2 h. This work provides an easy and general access to aqueous graphene suspensions of chemically non-modified graphene samples, an otherwise (almost) impossible task to achieve by other means. A detailed study of the stability of the relative dispersions is also reported.The preparation of graphene suspensions in water, without detergents or any other additives is achieved using freeze-dried graphene powders, produced by mechanochemical exfoliation of graphite. These powders of graphene can be safely stored or shipped, and promptly dissolved in aqueous media. The suspensions are relatively stable in terms of time, with a maximum loss of ~25% of the initial concentration at 2 h. This work provides an easy and general access to aqueous graphene suspensions of chemically non-modified graphene samples, an otherwise (almost) impossible task to achieve by other means. A detailed study of the stability of the relative dispersions is also reported. Electronic supplementary information (ESI) available: A video showing the dispersion process, the N 1s XPS spectrum of BMG, image of the graphite test in CCM, and the characterization of the GO employed. See DOI: 10.1039/c6nr03246j

  12. Symptom load and general function among patients with erythema migrans: a prospective study with a 1-year follow-up after antibiotic treatment in Norwegian general practice.

    PubMed

    Eliassen, Knut Eirik; Hjetland, Reidar; Reiso, Harald; Lindbæk, Morten; Tschudi-Madsen, Hedda

    2017-03-01

    Promptly treated erythema migrans (EM) has good prognosis. However, some patients report persistent symptoms. Do patients with EM have more symptoms than the general population? We describe individual symptoms and general function in EM-patients at time of diagnosis and one year after treatment. Prospective study with 1-year follow up after treatment. Questionnaires included a modified version of the Subjective Health Complaints Inventory, comprising three additional Lyme borreliosis (LB) related symptoms. General function was assessed using a five-point scale modified from the COOP/WONCA charts. Norwegian general practice. A total of 188 patients were included in a randomized controlled trial comparing three antibiotic regimens for EM, of whom 139 had complete data for this study. Individual symptoms, symptom load and general function. Mild symptoms were common, reported by 84.9% at baseline and by 85.6% at follow-up. At baseline, patients reported a mean of 5.4 symptoms, compared with 6.2 after one year. Severely bothersome symptoms and severely impaired general function were rare. Tiredness was the most reported symptom both at baseline and at follow-up. Palsy (other than facial) was the least reported symptom, but the only one with a significant increase. However, this was not associated to the EM. The symptom load was comparable to that reported in the general population. We found an increase in symptom load at follow-up that did not significantly affect general function. Monitoring patients' symptom loads prior to treatment reduce the probability of attributing follow-up symptoms to LB. Key points Erythema migrans has a good prognosis.Patients treated for erythema migrans have a slight increase in symptom load one year after treatment. This increase does not affect general function. The levels of subjective health complaints in patients treated for erythema migrans are comparable to the background population.

  13. 47 CFR 1.550 - Requests for new or modified call sign assignments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Requests for new or modified call sign assignments. 1.550 Section 1.550 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND... modified call sign assignments. See § 73.3550. ...

  14. Testing gravity with E{sub G}: mapping theory onto observations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Leonard, C. Danielle; Ferreira, Pedro G.; Heymans, Catherine, E-mail: danielle.leonard@physics.ox.ac.uk, E-mail: p.ferreira1@physics.ox.ac.uk, E-mail: heymans@roe.ac.uk

    We present a complete derivation of the observationally motivated definition of the modified gravity statistic E{sub G}. Using this expression, we investigate how variations to theory and survey parameters may introduce uncertainty in the general relativistic prediction of E{sub G}. We forecast errors on E{sub G} for measurements using two combinations of upcoming surveys, and find that theoretical uncertainties may dominate for a futuristic measurement. Finally, we compute predictions of E{sub G} under modifications to general relativity in the quasistatic regime, and comment on the pros and cons of using E{sub G} to test gravity with future surveys.

  15. Action growth for black holes in modified gravity

    NASA Astrophysics Data System (ADS)

    Sebastiani, Lorenzo; Vanzo, Luciano; Zerbini, Sergio

    2018-02-01

    The general form of the action growth for a large class of static black hole solutions in modified gravity which includes F (R ) -gravity models is computed. The cases of black hole solutions with nonconstant Ricci scalar are also considered, generalizing the results previously found and valid only for black holes with constant Ricci scalar. An argument is put forward to provide a physical interpretation of the results, which seem tightly connected with the generalized second law of black hole thermodynamics.

  16. Specificity and modifiability of cognitive biases in hypochondriasis.

    PubMed

    Gropalis, Maria; Bleichhardt, Gaby; Hiller, Wolfgang; Witthöft, Michael

    2013-06-01

    According to cognitive-behavioral models of hypochondriasis (HYP), biased attentional and memory processes related to health threat stimuli are crucial for the development and maintenance of severe health anxiety. Little is known about the specificity, temporal stability, and modifiability of these biases via psychotherapy. In an emotional Stroop and subsequent recognition task, the authors compared attention and memory processes for health-related words (illnesses, bodily complaints, and panic-related words) in patients with HYP (n = 32), other somatoform disorders (SFD; n = 27), and panic disorder (PD; n = 25). A control group consisted of 31 healthy participants (CG). All patients were reexamined after 4 months of cognitive-behavioral therapy (CBT). Patients with HYP showed a significant attentional bias toward all 3 target word categories. Evidence for a specific bias was found only for the PD group. General recognition performance for health threat and neutral words was best in the HYP group. After therapy, attentional bias had clearly decreased in the HYP and SFD patients. Patients with HYP can be characterized by attentional bias and more elaborate verbal processing. These irregularities tend to disappear after psychotherapy.

  17. On the generalized wormhole in the Eddington-inspired Born-Infeld gravity

    NASA Astrophysics Data System (ADS)

    Tamang, Amarjit; Potapov, Alexander A.; Lukmanova, Regina; Izmailov, Ramil; Nandi, Kamal K.

    2015-12-01

    In this paper, we wish to investigate certain observable effects in the recently obtained wormhole solution of the Eddington-inspired Born-Infeld (EiBI) theory, which generalizes the zero-mass Ellis-Bronnikov wormhole of general relativity. The solutions of EiBI theory contain an extra parameter κ having the inverse dimension of the cosmological constant Λ, and which is expected to modify various general relativistic observables such as the masses of wormhole mouths, tidal forces and light deflection. A remarkable result is that a non-zero κ could prevent the tidal forces in the geodesic orthonormal frame from becoming arbitrarily large near a small throat radius ({r}0˜ 0) contrary to what happens near a small Schwarzschild horizon radius (M˜ 0). The role of κ in the flare-out and energy conditions is also analyzed, which reveals that the energy conditions are violated. We show that the exotic matter in the EiBI wormhole cannot be interpreted as a phantom (ω =\\frac{{p}{{r}}}{ρ }\\lt -1) or ghost field ϕ of general relativity due to the fact that both ρ and p r are negative for all κ.

  18. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Antolin, J.; Instituto Carlos I de Fisica Teorica y Computacional, Universidad de Granada, ES-18071 Granada; Bouvrie, P. A.

    An alternative one-parameter measure of divergence is proposed, quantifying the discrepancy among general probability densities. Its main mathematical properties include (i) comparison among an arbitrary number of functions, (ii) the possibility of assigning different weights to each function according to its relevance on the comparative procedure, and (iii) ability to modify the relative contribution of different regions within the domain. Applications to the study of atomic density functions, in both conjugated spaces, show the versatility and universality of this divergence.

  19. Chimeras with multiple coherent regions

    NASA Astrophysics Data System (ADS)

    Ujjwal, Sangeeta Rani; Ramaswamy, Ramakrishna

    2013-09-01

    We study chimeric states in a coupled phase oscillator system with piecewise linear nonlocal coupling. By modifying the details of the coupling, it is possible to obtain multiple chimeric states with a specified number of coherent regions and with specified phase relationships. The case of a two-component chimera is illustrated and the generalization to arbitrary chimeric configurations is discussed. The phase relations between the two clusters of phase oscillators is described in some detail.

  20. Determination of linear short chain aliphatic aldehyde and ketone vapors in air using a polystyrene-coated quartz crystal nanobalance sensor.

    PubMed

    Mirmohseni, Abdolreza; Olad, Ali

    2010-01-01

    A polystyrene coated quartz crystal nanobalance (QCN) sensor was developed for use in the determination of a number of linear short-chain aliphatic aldehyde and ketone vapors contained in air. The quartz crystal was modified by a thin-layer coating of a commercial grade general purpose polystyrene (GPPS) from Tabriz petrochemical company using a solution casting method. Determination was based on frequency shifts of the modified quartz crystal due to the adsorption of analytes at the surface of modified electrode in exposure to various concentrations of analytes. The frequency shift was found to have a linear relation to the concentration of analytes. Linear calibration curves were obtained for 7-70 mg l(-1) of analytes with correlation coefficients in the range of 0.9935-0.9989 and sensitivity factors in the range of 2.07-6.74 Hz/mg l(-1). A storage period of over three months showed no loss in the sensitivity and performance of the sensor.

  1. Niche construction, sources of selection and trait coevolution.

    PubMed

    Laland, Kevin; Odling-Smee, John; Endler, John

    2017-10-06

    Organisms modify and choose components of their local environments. This 'niche construction' can alter ecological processes, modify natural selection and contribute to inheritance through ecological legacies. Here, we propose that niche construction initiates and modifies the selection directly affecting the constructor, and on other species, in an orderly, directed and sustained manner. By dependably generating specific environmental states, niche construction co-directs adaptive evolution by imposing a consistent statistical bias on selection. We illustrate how niche construction can generate this evolutionary bias by comparing it with artificial selection. We suggest that it occupies the middle ground between artificial and natural selection. We show how the perspective leads to testable predictions related to: (i) reduced variance in measures of responses to natural selection in the wild; (ii) multiple trait coevolution, including the evolution of sequences of traits and patterns of parallel evolution; and (iii) a positive association between niche construction and biodiversity. More generally, we submit that evolutionary biology would benefit from greater attention to the diverse properties of all sources of selection.

  2. Honeycomb-like Porous Carbon-Cobalt Oxide Nanocomposite for High-Performance Enzymeless Glucose Sensor and Supercapacitor Applications.

    PubMed

    Madhu, Rajesh; Veeramani, Vediyappan; Chen, Shen-Ming; Manikandan, Arumugam; Lo, An-Ya; Chueh, Yu-Lun

    2015-07-29

    Herein, we report the preparation of Pongam seed shells-derived activated carbon and cobalt oxide (∼2-10 nm) nanocomposite (PSAC/Co3O4) by using a general and facile synthesis strategy. The as-synthesized PSAC/Co3O4 samples were characterized by a variety of physicochemical techniques. The PSAC/Co3O4-modified electrode is employed in two different applications such as high performance nonenzymatic glucose sensor and supercapacitor. Remarkably, the fabricated glucose sensor is exhibited an ultrahigh sensitivity of 34.2 mA mM(-1) cm(-2) with a very low detection limit (21 nM) and long-term durability. The PSAC/Co3O4 modified stainless steel electrode possesses an appreciable specific capacitance and remarkable long-term cycling stability. The obtained results suggest the as-synthesized PSAC/Co3O4 is more suitable for the nonenzymatic glucose sensor and supercapacitor applications outperforming the related carbon based modified electrodes, rendering practical industrial applications.

  3. Strange stars in f( R) theories of gravity in the Palatini formalism

    NASA Astrophysics Data System (ADS)

    Panotopoulos, Grigoris

    2017-05-01

    In the present work we study strange stars in f( R) theories of gravity in the Palatini formalism. We consider two concrete well-known cases, namely the R+R^2/(6 M^2) model as well as the R-μ ^4/R model for two different values of the mass parameter M or μ . We integrate the modified Tolman-Oppenheimer-Volkoff equations numerically, and we show the mass-radius diagram for each model separately. The standard case corresponding to the General Relativity is also shown in the same figure for comparison. Our numerical results show that the interior solution can be vastly different depending on the model and/or the value of the parameter of each model. In addition, our findings imply that (i) for the cosmologically interesting values of the mass scales M,μ the effect of modified gravity on strange stars is negligible, while (ii) for the values predicting an observable effect, the modified gravity models discussed here would be ruled out by their cosmological effects.

  4. Ray-tracing in pseudo-complex General Relativity

    NASA Astrophysics Data System (ADS)

    Schönenbach, T.; Caspar, G.; Hess, P. O.; Boller, T.; Müller, A.; Schäfer, M.; Greiner, W.

    2014-07-01

    Motivated by possible observations of the black hole candidate in the centre of our Galaxy and the galaxy M87, ray-tracing methods are applied to both standard General Relativity (GR) and a recently proposed extension, the pseudo-complex GR (pc-GR). The correction terms due to the investigated pc-GR model lead to slower orbital motions close to massive objects. Also the concept of an innermost stable circular orbit is modified for the pc-GR model, allowing particles to get closer to the central object for most values of the spin parameter a than in GR. Thus, the accretion disc, surrounding a massive object, is brighter in pc-GR than in GR. Iron Kα emission-line profiles are also calculated as those are good observables for regions of strong gravity. Differences between the two theories are pointed out.

  5. General pulsed-field gradient signal attenuation expression based on a fractional integral modified-Bloch equation

    NASA Astrophysics Data System (ADS)

    Lin, Guoxing

    2018-10-01

    Anomalous diffusion has been investigated in many polymer and biological systems. The analysis of PFG anomalous diffusion relies on the ability to obtain the signal attenuation expression. However, the general analytical PFG signal attenuation expression based on the fractional derivative has not been previously reported. Additionally, the reported modified-Bloch equations for PFG anomalous diffusion in the literature yielded different results due to their different forms. Here, a new integral type modified-Bloch equation based on the fractional derivative for PFG anomalous diffusion is proposed, which is significantly different from the conventional differential type modified-Bloch equation. The merit of the integral type modified-Bloch equation is that the original properties of the contributions from linear or nonlinear processes remain unchanged at the instant of the combination. From the modified-Bloch equation, the general solutions are derived, which includes the finite gradient pulse width (FGPW) effect. The numerical evaluation of these PFG signal attenuation expressions can be obtained either by the Adomian decomposition, or a direct integration method that is fast and practicable. The theoretical results agree with the continuous-time random walk (CTRW) simulations performed in this paper. Additionally, the relaxation effect in PFG anomalous diffusion is found to be different from that in PFG normal diffusion. The new modified-Bloch equations and their solutions provide a fundamental tool to analyze PFG anomalous diffusion in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI).

  6. I-Love-Q relations for neutron stars in dynamical Chern Simons gravity

    NASA Astrophysics Data System (ADS)

    Gupta, Toral; Majumder, Barun; Yagi, Kent; Yunes, Nicolás

    2018-01-01

    Neutron stars are ideal to probe, not only nuclear physics, but also strong-field gravity. Approximate universal relations insensitive to the star’s internal structure exist among certain observables and are useful in testing general relativity, as they project out the uncertainties in the equation of state. One such set of universal relations between the moment of inertia (I), the tidal Love number and the quadrupole moment (Q) has been studied both in general relativity and in modified theories. In this paper, we study the relations in dynamical Chern–Simons gravity, a well-motivated, parity-violating effective field theory, extending previous work in various ways. First, we study how projected constraints on the theory using the I-Love relation depend on the measurement accuracy of I with radio observations and that of the Love number with gravitational-wave observations. Provided these quantities can be measured with future observations, we find that the latter could place bounds on dynamical Chern–Simons gravity that are six orders of magnitude stronger than current bounds. Second, we study the I–Q and Q-Love relations in this theory by constructing slowly-rotating neutron star solutions to quadratic order in spin. We find that the approximate universality continues to hold in dynamical Chern–Simons gravity, and in fact, it becomes stronger than in general relativity, although its existence depends on the normalization of the dimensional coupling constant of the theory. Finally, we study the variation of the eccentricity of isodensity contours inside a star and its relation to the degree of universality. We find that, in most cases, the eccentricity variation is smaller in dynamical Chern–Simons gravity than in general relativity, providing further support to the idea that the approximate self-similarity of isodensity contours is responsible for universality.

  7. Considering the Use of General and Modified Assessment Items in Computerized Adaptive Testing

    ERIC Educational Resources Information Center

    Wyse, Adam E.; Albano, Anthony D.

    2015-01-01

    This article used several data sets from a large-scale state testing program to examine the feasibility of combining general and modified assessment items in computerized adaptive testing (CAT) for different groups of students. Results suggested that several of the assumptions made when employing this type of mixed-item CAT may not be met for…

  8. Parametrizing growth in dark energy and modified gravity models

    NASA Astrophysics Data System (ADS)

    Resco, Miguel Aparicio; Maroto, Antonio L.

    2018-02-01

    It is well known that an extremely accurate parametrization of the growth function of matter density perturbations in Λ CDM cosmology, with errors below 0.25%, is given by f (a )=Ωmγ(a ) with γ ≃0.55 . In this work, we show that a simple modification of this expression also provides a good description of growth in modified gravity theories. We consider the model-independent approach to modified gravity in terms of an effective Newton constant written as μ (a ,k )=Geff/G and show that f (a )=β (a )Ωmγ(a ) provides fits to the numerical solutions with similar accuracy to that of Λ CDM . In the time-independent case with μ =μ (k ), simple analytic expressions for β (μ ) and γ (μ ) are presented. In the time-dependent (but scale-independent) case μ =μ (a ), we show that β (a ) has the same time dependence as μ (a ). As an example, explicit formulas are provided in the Dvali-Gabadadze-Porrati (DGP) model. In the general case, for theories with μ (a ,k ), we obtain a perturbative expansion for β (μ ) around the general relativity case μ =1 which, for f (R ) theories, reaches an accuracy below 1%. Finally, as an example we apply the obtained fitting functions in order to forecast the precision with which future galaxy surveys will be able to measure the μ parameter.

  9. Infrared modified gravity with propagating torsion: Instability of torsionfull de Sitter-like solutions

    NASA Astrophysics Data System (ADS)

    Nikiforova, Vasilisa; Damour, Thibault

    2018-06-01

    We continue the exploration of the consistency of a modified-gravity theory that generalizes general relativity by including a dynamical torsion in addition to the dynamical metric. The six-parameter theory we consider was found to be consistent around arbitrary torsionless Einstein backgrounds, in spite of its containing a (notoriously delicate) massive spin-2 excitation. At zero bare cosmological constant, this theory was found to admit a self-accelerating solution whose exponential expansion is sustained by a nonzero torsion background. The scalar-type perturbations of the latter torsionfull self-accelerating solution were recently studied and were found to preserve the number of propagating scalar degrees of freedom, but to exhibit, for some values of the torsion background, some exponential instabilities (of a rather mild type). Here, we study the tensor-type and vector-type perturbations of the torsionfull self-accelerating solution, and of its deformation by a nonzero bare cosmological constant. We find strong, "gradient" instabilities in the vector sector. No tuning of the parameters of the theory can kill these instabilities without creating instabilities in the other sectors. Further work is needed to see whether generic torsionfull backgrounds are prone to containing gradient instabilities, or if the instabilities we found are mainly due to the (generalized) self-accelerating nature of the special de Sitter backgrounds we considered.

  10. On gauge invariant cosmological perturbations in UV-modified Hořava gravity

    NASA Astrophysics Data System (ADS)

    Shin, Sunyoung; Park, Mu-In

    2017-12-01

    We consider gauge invariant cosmological perturbations in UV-modified, z = 3 (non-projectable) Hořava gravity with one scalar matter field, which has been proposed as a renormalizable gravity theory without the ghost problem in four dimensions. In order to exhibit its dynamical degrees of freedom, we consider the Hamiltonian reduction method and find that, by solving all the constraint equations, the degrees of freedom are the same as those of Einstein gravity: one scalar and two tensor (graviton) modes when a scalar matter field presents. However, we confirm that there is no extra graviton modes and general relativity is recovered in IR, which achieves the consistency of the model. From the UV-modification terms which break the detailed balance condition in UV, we obtain scale-invariant power spectrums for non-inflationary backgrounds, like the power-law expansions, without knowing the details of early expansion history of Universe. This could provide a new framework for the Big Bang cosmology. Moreover, we find that tensor and scalar fluctuations travel differently in UV, generally. We present also some clarifying remarks about confusing points in the literatures.

  11. Soy Intake Modifies the Relation Between Urinary Bisphenol A Concentrations and Pregnancy Outcomes Among Women Undergoing Assisted Reproduction.

    PubMed

    Chavarro, Jorge E; Mínguez-Alarcón, Lidia; Chiu, Yu-Han; Gaskins, Audrey J; Souter, Irene; Williams, Paige L; Calafat, Antonia M; Hauser, Russ

    2016-03-01

    Experimental data in rodents suggest that the adverse reproductive health effects of bisphenol A (BPA) can be modified by intake of soy phytoestrogens. Whether the same is true in humans is not known. The purpose of this study was to evaluate whether soy consumption modifies the relation between urinary BPA levels and infertility treatment outcomes among women undergoing assisted reproduction. The study was conducted in a fertility center in a teaching hospital. We evaluated 239 women enrolled between 2007 and 2012 in the Environment and Reproductive Health (EARTH) Study, a prospective cohort study, who underwent 347 in vitro fertilization (IVF) cycles. Participants completed a baseline questionnaire and provided up to 2 urine samples in each treatment cycle before oocyte retrieval. IVF outcomes were abstracted from electronic medical records. We used generalized linear mixed models with interaction terms to evaluate whether the association between urinary BPA concentrations and IVF outcomes was modified by soy intake. Live birth rates per initiated treatment cycle were measured. Soy food consumption modified the association of urinary BPA concentration with live birth rates (P for interaction = .01). Among women who did not consume soy foods, the adjusted live birth rates per initiated cycle in increasing quartiles of cycle-specific urinary BPA concentrations were 54%, 35%, 31%, and 17% (P for trend = .03). The corresponding live birth rates among women reporting pretreatment consumption of soy foods were 38%, 42%, 47%, and 49% (P for trend = 0.35). A similar pattern was found for implantation (P for interaction = .02) and clinical pregnancy rates (P for interaction = .03) per initiated cycle, where urinary BPA was inversely related to these outcomes among women not consuming soy foods but unrelated to them among soy consumers. Soy food intake may protect against the adverse reproductive effects of BPA. As these findings represent the first report suggesting a potential interaction between soy and BPA in humans, they should be further evaluated in other populations.

  12. Hierarchies of Manakov-Santini Type by Means of Rota-Baxter and Other Identities

    NASA Astrophysics Data System (ADS)

    Szablikowski, Błażej

    2016-02-01

    The Lax-Sato approach to the hierarchies of Manakov-Santini type is formalized in order to extend it to a more general class of integrable systems. For this purpose some linear operators are introduced, which must satisfy some integrability conditions, one of them is the Rota-Baxter identity. The theory is illustrated by means of the algebra of Laurent series, the related hierarchies are classified and examples, also new, of Manakov-Santini type systems are constructed, including those that are related to the dispersionless modified Kadomtsev-Petviashvili equation and so called dispersionless r-th systems.

  13. Cosmic growth and expansion conjoined

    NASA Astrophysics Data System (ADS)

    Linder, Eric V.

    2017-01-01

    Cosmological measurements of both the expansion history and growth history have matured, and the two together provide an important test of general relativity. We consider their joint evolutionary track, showing that this has advantages in distinguishing cosmologies relative to considering them individually or at isolated redshifts. In particular, the joint comparison relaxes the shape degeneracy that makes fσ8(z) curves difficult to separate from the overall growth amplitude. The conjoined method further helps visualization of which combinations of redshift ranges provide the clearest discrimination. We examine standard dark energy cosmologies, modified gravity, and "stuttering" growth, each showing distinct signatures.

  14. Relating transverse-momentum-dependent and collinear factorization theorems in a generalized formalism

    NASA Astrophysics Data System (ADS)

    Collins, J.; Gamberg, L.; Prokudin, A.; Rogers, T. C.; Sato, N.; Wang, B.

    2016-08-01

    We construct an improved implementation for combining transverse-momentum-dependent (TMD) factorization and collinear factorization. TMD factorization is suitable for low transverse momentum physics, while collinear factorization is suitable for high transverse momenta and for a cross section integrated over transverse momentum. The result is a modified version of the standard W +Y prescription traditionally used in the Collins-Soper-Sterman (CSS) formalism and related approaches. We further argue that questions regarding the shape and Q dependence of the cross sections at lower Q are largely governed by the matching to the Y term.

  15. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Salzano, Vincenzo; Da̧browski, Mariusz P.; Mota, David F.

    Modified gravity theories with a screening mechanism have acquired much interest recently in the quest for a viable alternative to General Relativity on cosmological scales, given their intrinsic property of being able to pass Solar System scale tests and, at the same time, to possibly drive universe acceleration on much larger scales. Here, we explore the possibility that the same screening mechanism, or its breaking at a certain astrophysical scale, might be responsible of those gravitational effects which, in the context of general relativity, are generally attributed to Dark Matter. We consider a recently proposed extension of covariant Galileon modelsmore » in the so-called ''beyond Horndeski'' scenario, where a breaking of the Vainshtein mechanism is possible and, thus, some peculiar observational signatures should be detectable and make it distinguishable from general relativity. We apply this model to a sample of clusters of galaxies observed under the CLASH survey, using both new data from gravitational lensing events and archival data from X-ray intra-cluster hot gas observations. In particular, we use the latter to model the gas density, and then use it as the only ingredient in the matter clusters' budget to calculate the expected lensing convergence map. Results show that, in the context of this extended Galileon, the assumption of having only gas and no Dark Matter at all in the clusters is able to match observations. We also obtain narrow and very interesting bounds on the parameters which characterize this model. In particular, we find that, at least for one of them, the general relativity limit is excluded at 2σ confidence level, thus making this model clearly statistically different and competitive with respect to general relativity.« less

  16. No need for dark matter in galaxy clusters within Galileon theory

    NASA Astrophysics Data System (ADS)

    Salzano, Vincenzo; Mota, David F.; Dabrowski, Mariusz P.; Capozziello, Salvatore

    2016-10-01

    Modified gravity theories with a screening mechanism have acquired much interest recently in the quest for a viable alternative to General Relativity on cosmological scales, given their intrinsic property of being able to pass Solar System scale tests and, at the same time, to possibly drive universe acceleration on much larger scales. Here, we explore the possibility that the same screening mechanism, or its breaking at a certain astrophysical scale, might be responsible of those gravitational effects which, in the context of general relativity, are generally attributed to Dark Matter. We consider a recently proposed extension of covariant Galileon models in the so-called ``beyond Horndeski'' scenario, where a breaking of the Vainshtein mechanism is possible and, thus, some peculiar observational signatures should be detectable and make it distinguishable from general relativity. We apply this model to a sample of clusters of galaxies observed under the CLASH survey, using both new data from gravitational lensing events and archival data from X-ray intra-cluster hot gas observations. In particular, we use the latter to model the gas density, and then use it as the only ingredient in the matter clusters' budget to calculate the expected lensing convergence map. Results show that, in the context of this extended Galileon, the assumption of having only gas and no Dark Matter at all in the clusters is able to match observations. We also obtain narrow and very interesting bounds on the parameters which characterize this model. In particular, we find that, at least for one of them, the general relativity limit is excluded at 2σ confidence level, thus making this model clearly statistically different and competitive with respect to general relativity.

  17. Fate of Large-Scale Structure in Modified Gravity After GW170817 and GRB170817A

    NASA Astrophysics Data System (ADS)

    Amendola, Luca; Kunz, Martin; Saltas, Ippocratis D.; Sawicki, Ignacy

    2018-03-01

    The coincident detection of gravitational waves (GW) and a gamma-ray burst from a merger of neutron stars has placed an extremely stringent bound on the speed of GWs. We showed previously that the presence of gravitational slip (η ) in cosmology is intimately tied to modifications of GW propagation. This new constraint implies that the only remaining viable source of gravitational slip is a conformal coupling to gravity in scalar-tensor theories, while viable vector-tensor theories cannot now generate gravitational slip at all. We discuss structure formation in the remaining viable models, demonstrating that (i) the dark-matter growth rate must now be at least as fast as in general relativity (GR), with the possible exception of that beyond the Horndeski model, and (ii) if there is any scale dependence at all in the slip parameter, it is such that it takes the GR value at large scales. We show a consistency relation that must be violated if gravity is modified.

  18. Iontophoretic transport of oligonucleotides across human epidermal membrane: a study of the Nernst-Planck model.

    PubMed

    Li, S K; Ghanem, A H; Teng, C L; Hardee, G E; Higuchi, W I

    2001-07-01

    The objective of this study was to investigate the transport behavior of a series of oligonucleotides with human epidermal membrane (HEM) and to examine the applicability of the modified NERNST-PLANCK model to transdermal iontophoresis of these macromolecules. Iontophoretic transport experiments were first carried out in a synthetic model membrane system (Nuclepore membranes) with a four-electrode potentiostat to examine the baseline modified NERNST-PLANCK model. The modified NERNST-PLANCK model derived from the Einstein relation and the Stokes-Einstein equation taken from previous work did not hold for the oligonucleotides. Results obtained in the Nuclepore studies were, however, consistent with predictions of the modified NERNST-PLANCK model using the experimentally determined electromobilities and diffusion coefficients. The electromobilities of the oligonucleotides (determined by capillary electrophoresis) were found to be more than a factor of two smaller than expected from the Einstein relation between electromobilities and diffusion coefficients (the latter determined in diffusion cell experiments). A correlation between these electromobilities and the theoretical electromobilities estimated by considering the effects of counterion binding and the effects of mobility reduction according to colloid theory was also observed. These results suggest that the modified NERNST-PLANCK model predictions are satisfactory only when the electromobilities and the effective molecular size of the oligonucleotides are known and are used directly to predict the iontophoretically enhanced transport. Results with the HEM experiments generally agreed with model predictions based on the experimental electromobilities. The oligonucleotide HEM flux data also suggest the existence of pores with effective pore radii greater than the effective radii estimated in previous studies with small molecular weight model permeants.

  19. 76 FR 39256 - Airworthiness Directives; Dassault Aviation Model FALCON 7X Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... include modifying the applicable wiring and layout, a general visual inspection for absence of marks of... March 3, 2010. (2) Modify the applicable wiring and layout, in accordance with the Accomplishment... modifying the applicable wiring and layout, in accordance with Dassault Mandatory Service Bulletin 7X- 006...

  20. GR 20 parallel session A3: modified gravity

    NASA Astrophysics Data System (ADS)

    Hořava, Petr; Mohd, Arif; Melby-Thompson, Charles M.; Shawhan, Peter

    2014-05-01

    The parallel session (A3), on "Modified Gravity", enjoyed one on the largest number of abstract submissions (over 80), resulting in the selection of 24 oral presentations. The three short papers presented in the following sections are based on the session talks by Arif Mohd on thermodynamics of universal horizons in Einstein-Æther theory, Conformal anomalies in Hořava-Lifshitz gravity by Charles Melby-Thompson and detectability of scalar gravitational waves by LIGO and Virgo by Peter Shawhan. They have been selected as a representative sample, to illustrate some of the best in the remarkable and encouraging variety of topics discussed in the session—ranging from highly theoretical, to phenomenological, observational, and experimental—with all these areas playing an integral part in our quest to understand the limits of standard general relativity.

  1. Rock Fracture Toughness Under Mode II Loading: A Theoretical Model Based on Local Strain Energy Density

    NASA Astrophysics Data System (ADS)

    Rashidi Moghaddam, M.; Ayatollahi, M. R.; Berto, F.

    2018-01-01

    The values of mode II fracture toughness reported in the literature for several rocks are studied theoretically by using a modified criterion based on strain energy density averaged over a control volume around the crack tip. The modified criterion takes into account the effect of T-stress in addition to the singular terms of stresses/strains. The experimental results are related to mode II fracture tests performed on the semicircular bend and Brazilian disk specimens. There are good agreements between theoretical predictions using the generalized averaged strain energy density criterion and the experimental results. The theoretical results reveal that the value of mode II fracture toughness is affected by the size of control volume around the crack tip and also the magnitude and sign of T-stress.

  2. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vanderveld, R. Ali; Flanagan, Eanna E.; Wasserman, Ira

    Recently, there have been suggestions that the Type Ia supernova data can be explained using only general relativity and cold dark matter with no dark energy. In 'Swiss cheese' models of the Universe, the standard Friedmann-Robertson-Walker picture is modified by the introduction of mass-compensating spherical inhomogeneities, typically described by the Lemaitre-Tolman-Bondi metric. If these inhomogeneities correspond to underdense cores surrounded by mass-compensating overdense shells, then they can modify the luminosity distance-redshift relation in a way that can mimic accelerated expansion. It has been argued that this effect could be large enough to explain the supernova data without introducing dark energymore » or modified gravity. We show that the large apparent acceleration seen in some models can be explained in terms of standard weak field gravitational lensing together with insufficient randomization of void locations. The underdense regions focus the light less than the homogeneous background, thus dimming supernovae in a way that can mimic the effects of acceleration. With insufficient randomization of the spatial location of the voids and of the lines of sight, coherent defocusing can lead to anomalously large demagnification effects. We show that a proper randomization of the voids and lines of sight reduces the effect to the point that it can no longer explain the supernova data.« less

  3. Mars Pathfinder Landing Site: Evidence for a Change in Wind Regime from Lander and Orbiter Data

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Kraft, Michael D.; Kuzmin, Ruslan O.; Bridges, Nathan T.

    2000-01-01

    Surface features related to the wind are observed in the vicinity of the Mars Pathfinder (MPR landing site data from the lander and in data from orbit by the Viking Orbiter and Mars Global Surveyor missions. Features seen from the surface include wind tails associated with small rocks, barchanoid duneforms, ripplelike patterns, and ventifact flutes cut into some rocks. Features seen from orbit include wind tails associated with impact craters, ridges inferred to be duneforms, and modified crater rims interpreted to have been eroded and mantled by windblown material. The orientations of these features show two prevailing directions. One is inferred to represent winds from the northeast, which is consistent with strongest winds predicted by a general circulation model to occur during the Martian northern winter under current conditions. A second wind blowing from the ESE was responsible for modifying the crater rims and cutting some of the ventifacts. The two wind regimes could reflect a change in climate related to Mars' obliquity or some other, unknown factor. Regardless of the cause, the MPF area has been subjected to a complex pattern of winds and supply of small particles, and the original surface formed by sedimentary processes from Tiu and Ares Vallis flooding events has been modified by repeated burial and exhumation.

  4. Constraints on deviations from ΛCDM within Horndeski gravity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bellini, Emilio; Cuesta, Antonio J.; Jimenez, Raul

    2016-02-01

    Recent anomalies found in cosmological datasets such as the low multipoles of the Cosmic Microwave Background or the low redshift amplitude and growth of clustering measured by e.g., abundance of galaxy clusters and redshift space distortions in galaxy surveys, have motivated explorations of models beyond standard ΛCDM. Of particular interest are models where general relativity (GR) is modified on large cosmological scales. Here we consider deviations from ΛCDM+GR within the context of Horndeski gravity, which is the most general theory of gravity with second derivatives in the equations of motion. We adopt a parametrization in which the four additional Horndeskimore » functions of time α{sub i}(t) are proportional to the cosmological density of dark energy Ω{sub DE}(t). Constraints on this extended parameter space using a suite of state-of-the art cosmological observations are presented for the first time. Although the theory is able to accommodate the low multipoles of the Cosmic Microwave Background and the low amplitude of fluctuations from redshift space distortions, we find no significant tension with ΛCDM+GR when performing a global fit to recent cosmological data and thus there is no evidence against ΛCDM+GR from an analysis of the value of the Bayesian evidence ratio of the modified gravity models with respect to ΛCDM, despite introducing extra parameters. The posterior distribution of these extra parameters that we derive return strong constraints on any possible deviations from ΛCDM+GR in the context of Horndeski gravity. We illustrate how our results can be applied to a more general frameworks of modified gravity models.« less

  5. Selective processing of smoking-related cues in smokers: manipulation of deprivation level and comparison of three measures of processing bias.

    PubMed

    Mogg, Karin; Bradley, Brendan P

    2002-12-01

    Recent theories of addiction suggest that an attentional bias for drug-related cues plays an important role in maintaining drug-taking behaviours. A key feature of the present study is that it used three different measures of processing bias for linguistic and pictorial smoking-related cues: masked and unmasked conditions of the modified Stroop task, and a pictorial version of the visual probe task. Participants were smokers (n = 27), who were tested twice, with deprivation level manipulated as a within-subjects variable. They were asked to abstain from smoking for 12 h before one session, and to smoke normally before the other. Results were consistent with an attentional bias for smoking-related pictures on the visual probe task, and for smoking-related words in the unmasked condition of the modified Stroop task. The latter bias was most strongly predicted by self-reported urge to smoke, rather than by the deprivation manipulation. There was no evidence of a preconscious bias for smoking cues. The three measures of cognitive bias (from masked and unmasked Stroop and visual probe tasks) were not significantly correlated with each other, which suggests they may tap different underlying mechanisms. We discuss the results with respect to conceptualizations of selective attention, addiction and motivational states in general.

  6. Targeting allosteric disulphide bonds in cancer.

    PubMed

    Hogg, Philip J

    2013-06-01

    Protein action in nature is generally controlled by the amount of protein produced and by chemical modification of the protein, and both are often perturbed in cancer. The amino acid side chains and the peptide and disulphide bonds that bind the polypeptide backbone can be post-translationally modified. Post-translational cleavage or the formation of disulphide bonds are now being identified in cancer-related proteins and it is timely to consider how these allosteric bonds could be targeted for new therapies.

  7. Application of propagation predictions to Earth/space telecommunications system design

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The corresponding between a given propagation phenomenon and system performance is considered. Propagation data are related to system performance parameters, allowing the systems engineer to perform the analyses determining how well requirements are met by a given system design, and enabling the systems engineer to modify that design if necessary. The various ways of specifying performance criteria for different kinds of systems are discussed, and a general procedure for system design is presented and demonstrated.

  8. Correlation Between Symptom Severity and Health-Related Life Quality of a Population With Gastroesophageal Reflux Disease.

    PubMed

    Lee, Shou-Wu; Lee, Teng-Yu; Lien, Han-Chung; Peng, Yen-Chun; Yeh, Hong-Jeh; Chang, Chi-Sen

    2017-04-01

    Gastroesophageal reflux disease (GERD) is a chronic disease with a negative impact on the quality of life. The aim of this study was to investigate the reflux symptoms and the health-related quality of life in a population with GERD. Data from patients with GERD, according to the Montreal definition, were collected between January and December 2009. The enrolled patients were classified by different reflux symptoms according to the modified Chinese GERDQ. The general demographic data, the modified GERD impact scores and the SF-36 questionnaire scores of these groups of patients were analyzed. A total of 173 patients were enrolled, and the general data, endoscopic findings and lifestyle habits of the participants with different severity of heartburn or regurgitation were all similar. The patients with moderate severity of reflux symptoms had significant lower SF-36 scores than those with mild severity. The cases with advanced heartburn severity owned the lowest scores among all cases. The impact on the daily activity of each affected individual had a positive association with the stronger severity of reflux symptom. The life quality of a population with GERD achieved the meaningful declination in participants with the moderate severity of heartburn or regurgitation. The severity of the reflux symptoms had a greater impact on the normal daily activity of the patients with GERD. The cases with advanced severity of heartburn had the worst well-being.

  9. The relevance of gene transfer to the safety of food and feed derived from genetically modified (GM) plants.

    PubMed

    van den Eede, G; Aarts, H; Buhk, H-J; Corthier, G; Flint, H J; Hammes, W; Jacobsen, B; Midtvedt, T; van der Vossen, J; von Wright, A; Wackernagel, W; Wilcks, A

    2004-07-01

    In 2000, the thematic network ENTRANSFOOD was launched to assess four different topics that are all related to the testing or assessment of food containing or produced from genetically modified organisms (GMOs). Each of the topics was linked to a European Commission (EC)-funded large shared cost action (see http://www.entransfood.com). Since the exchange of genetic information through horizontal (lateral) gene transfer (HGT) might play a more important role, in quantity and quality, than hitherto imagined, a working group dealing with HGT in the context of food and feed safety was established. This working group was linked to the GMOBILITY project (GMOBILITY, 2003) and the results of the deliberations are laid down in this review paper. HGT is reviewed in relation to the potential risks of consuming food or feed derived from transgenic crops. First, the mechanisms for obtaining transgenic crops are described. Next, HGT mechanisms and its possible evolutionary role are described. The use of marker genes is presented in detail as a special case for genes that may pose a risk. Furthermore, the exposure to GMOs and in particular to genetically modified (GM) deoxyribonucleic acid (DNA) is discussed as part of the total risk assessment. The review finishes off with a number of conclusions related to GM food and feed safety. The aim of this paper is to provide a comprehensive overview to assist risk assessors as well as regulators and the general public in understanding the safety issues related to these mechanisms. Copryright 2004 Elsevier Ltd.

  10. SWITCH: rationale, design, and implementation of a community, school, and family-based intervention to modify behaviors related to childhood obesity

    PubMed Central

    Eisenmann, Joey C; Gentile, Douglas A; Welk, Gregory J; Callahan, Randi; Strickland, Sarah; Walsh, Monica; Walsh, David A

    2008-01-01

    Background Although several previous projects have attempted to address the issue of child obesity through school-based interventions, the overall effectiveness of school-based programs on health-related outcomes in youth has been poor. Thus, it has been suggested that multi-level interventions that aim to influence healthy lifestyle behaviors at the community, school and family levels may prove more successful in the prevention of childhood obesity. Methods/Design This paper describes the rationale, design, and implementation of a community-, school-, and family-based intervention aimed at modifying key behaviors (physical activity, screen time (Internet, television, video games), and nutrition) related to childhood obesity among third through fifth graders in two mid-western cities. The intervention involves a randomized study of 10 schools (5 intervention and 5 control schools). The intervention is being conducted during the duration of the academic year – approximately 9 months – and includes baseline and post-intervention measurements of physical activity, dietary intake, screen time and body composition. Discussion We hope this report will be useful to researchers, public health professionals, and school administrators and health professionals (nurses and physical/health educators) seeking to develop similar prevention programs. It is obvious that more collaborative, inter-disciplinary, multi-level work is needed before a proven, effective intervention package to modify behaviors related to childhood obesity can be generally recommended. It is our hope that SWITCH is a step in that direction. Trial Registration ClinicalTrials.gov NCT00685555 PMID:18588706

  11. Spontaneous scalarization with an extremely massive field and heavy neutron stars

    NASA Astrophysics Data System (ADS)

    Morisaki, Soichiro; Suyama, Teruaki

    2017-10-01

    We investigate the internal structure and the mass-radius relation of neutron stars in a recently proposed scalar-tensor theory dubbed asymmetron in which a massive scalar field undergoes spontaneous scalarization inside neutron stars. We focus on the case where the Compton wavelength is shorter than 10 km, which has not been investigated in the literature. By solving the modified Einstein equations, either purely numerically or by partially using a semianalytic method, we find that not only the weakening of gravity by spontaneous scalarization but also the scalar force affect the internal structure significantly in the massive case. We also find that the maximum mass of neutron stars is larger for certain parameter sets than that in general relativity and reaches 2 M⊙ even if the effect of strange hadrons is taken into account. There is even a range of parameters where the maximum mass of neutron stars largely exceeds the threshold that violates the causality bound in general relativity.

  12. Flow interaction with a flexible viscoelastic sheet

    NASA Astrophysics Data System (ADS)

    Shoele, Kourosh

    2017-11-01

    Many new engineered materials and almost all soft biological tissues are made up of heterogeneous multi-scale components with complex viscoelastic behavior. This implies that their macro constitutive relations cannot be modeled sufficiently with a typical integer-order viscoelastic relation and a more general mode is required. Here, we study the flow-induced vibration of a viscoelastic sheet where a generalized fractional constitutive model is employed to represent the relation between the bending stress and the temporal response of the structure. A new method is proposed for the calculation of the convolution integral inside the fractal model and its computational benefits will be discussed. Using a coupled fluid-structure interaction (FSI) methodology based on the immersed boundary technique, dynamic fluttering modes of the structure as a result of the fluid force will be presented and the role of fractal viscoelasticity on the dynamic of the structure will be shown. Finally, it will be argued how the stress relaxation modifies the flow-induced oscillatory responses of this benchmark problem.

  13. Generalization of the Bogoliubov-Zubarev Theorem for Dynamic Pressure to the Case of Compressibility

    NASA Astrophysics Data System (ADS)

    Rudoi, Yu. G.

    2018-01-01

    We present the motivation, formulation, and modified proof of the Bogoliubov-Zubarev theorem connecting the pressure of a dynamical object with its energy within the framework of a classical description and obtain a generalization of this theorem to the case of dynamical compressibility. In both cases, we introduce the volume of the object into consideration using a singular addition to the Hamiltonian function of the physical object, which allows using the concept of the Bogoliubov quasiaverage explicitly already on a dynamical level of description. We also discuss the relation to the same result known as the Hellmann-Feynman theorem in the framework of the quantum description of a physical object.

  14. Parameterised post-Newtonian expansion in screened regions

    NASA Astrophysics Data System (ADS)

    McManus, Ryan; Lombriser, Lucas; Peñarrubia, Jorge

    2017-12-01

    The parameterised post-Newtonian (PPN) formalism has enabled stringent tests of static weak-field gravity in a theory-independent manner. Here we incorporate screening mechanisms of modified gravity theories into the framework by introducing an effective gravitational coupling and defining the PPN parameters as functions of position. To determine these functions we develop a general method for efficiently performing the post-Newtonian expansion in screened regimes. For illustration, we derive all the PPN functions for a cubic galileon and a chameleon model. We also analyse the Shapiro time delay effect for these two models and find no deviations from General Relativity insofar as the signal path and the perturbing mass reside in a screened region of space.

  15. One gravitational potential or two? Forecasts and tests.

    PubMed

    Bertschinger, Edmund

    2011-12-28

    The metric of a perturbed Robertson-Walker space-time is characterized by three functions: a scale-factor giving the expansion history and two potentials that generalize the single potential of Newtonian gravity. The Newtonian potential induces peculiar velocities and, from these, the growth of matter fluctuations. Massless particles respond equally to the Newtonian potential and to a curvature potential. The difference of the two potentials, called the gravitational slip, is predicted to be very small in general relativity, but can be substantial in modified gravity theories. The two potentials can be measured, and gravity tested on cosmological scales, by combining weak gravitational lensing or the integrated Sachs-Wolfe effect with galaxy peculiar velocities or clustering.

  16. Post-Newtonian parameter γ in generalized non-local gravity

    NASA Astrophysics Data System (ADS)

    Zhang, Xue; Wu, YaBo; Yang, WeiQiang; Zhang, ChengYuan; Chen, BoHai; Zhang, Nan

    2017-10-01

    We investigate the post-Newtonian parameter γ and derive its formalism in generalized non-local (GNL) gravity, which is the modified theory of general relativity (GR) obtained by adding a term m 2 n-2 R☐-n R to the Einstein-Hilbert action. Concretely, based on parametrizing the generalized non-local action in which gravity is described by a series of dynamical scalar fields ϕ i in addition to the metric tensor g μν, the post-Newtonian limit is computed, and the effective gravitational constant as well as the post-Newtonian parameters are directly obtained from the generalized non-local gravity. Moreover, by discussing the values of the parametrized post-Newtonian parameters γ, we can compare our expressions and results with those in Hohmann and Järv et al. (2016), as well as current observational constraints on the values of γ in Will (2006). Hence, we draw restrictions on the nonminimal coupling terms F̅ around their background values.

  17. 46 CFR 54.01-25 - Miscellaneous pressure components (modifies UG-11).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Miscellaneous pressure components (modifies UG-11). 54.01-25 Section 54.01-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS General Requirements § 54.01-25 Miscellaneous pressure components (modifies UG-11). (a) Pressure components for pressure...

  18. 46 CFR 54.01-25 - Miscellaneous pressure components (modifies UG-11).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Miscellaneous pressure components (modifies UG-11). 54.01-25 Section 54.01-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS General Requirements § 54.01-25 Miscellaneous pressure components (modifies UG-11). (a) Pressure components for pressure...

  19. 46 CFR 54.01-25 - Miscellaneous pressure components (modifies UG-11).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Miscellaneous pressure components (modifies UG-11). 54.01-25 Section 54.01-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS General Requirements § 54.01-25 Miscellaneous pressure components (modifies UG-11). (a) Pressure components for pressure...

  20. 46 CFR 54.01-25 - Miscellaneous pressure components (modifies UG-11).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Miscellaneous pressure components (modifies UG-11). 54.01-25 Section 54.01-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS General Requirements § 54.01-25 Miscellaneous pressure components (modifies UG-11). (a) Pressure components for pressure...

  1. 46 CFR 54.01-25 - Miscellaneous pressure components (modifies UG-11).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Miscellaneous pressure components (modifies UG-11). 54.01-25 Section 54.01-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS General Requirements § 54.01-25 Miscellaneous pressure components (modifies UG-11). (a) Pressure components for pressure...

  2. Noncommutative geometry inspired Einstein–Gauss–Bonnet black holes

    NASA Astrophysics Data System (ADS)

    Ghosh, Sushant G.

    2018-04-01

    Low energy limits of a string theory suggests that the gravity action should include quadratic and higher-order curvature terms, in the form of dimensionally continued Gauss–Bonnet densities. Einstein–Gauss–Bonnet is a natural extension of the general relativity to higher dimensions in which the first and second-order terms correspond, respectively, to general relativity and Einstein–Gauss–Bonnet gravity. We obtain five-dimensional (5D) black hole solutions, inspired by a noncommutative geometry, with a static spherically symmetric, Gaussian mass distribution as a source both in the general relativity and Einstein–Gauss–Bonnet gravity cases, and we also analyzes their thermodynamical properties. Owing the noncommutative corrected black hole, the thermodynamic quantities have also been modified, and phase transition is shown to be achievable. The phase transitions for the thermodynamic stability, in both the theories, are characterized by a discontinuity in the specific heat at r_+=rC , with the stable (unstable) branch for r < (>) rC . The metric of the noncommutative inspired black holes smoothly goes over to the Boulware–Deser solution at large distance. The paper has been appended with a calculation of black hole mass using holographic renormalization.

  3. Modified Bloch equations and spectral hole burning in solids

    NASA Astrophysics Data System (ADS)

    Asadullina, N. Ya; Asadullin, T. Ya; Asadullin, Ya Ya

    2001-06-01

    On the grounds of Bloch equations modified by taking into account the power dependence of the dispersion and damping parameters, we give general expressions for hole shapes burnt in the absorption and polarization spectra of the two-level systems. The general expressions are used for detailed numerical calculations of the hole shapes and hole widths in a concrete paramagnetic system (quartz with [AlO4]0 centres). This system earlier was studied experimentally and theoretically through the transient nutation and free induction decay methods. The results on the hole width in our modified-Bloch-equations model are in good qualitative agreement with the FID data.

  4. Moment of inertia of neutron star crust in alternative and modified theories of gravity

    NASA Astrophysics Data System (ADS)

    Staykov, Kalin V.; Ekşi, K. Yavuz; Yazadjiev, Stoytcho S.; Türkoǧlu, M. Metehan; Arapoǧlu, A. Savaş

    2016-07-01

    The glitch activity of young pulsars arises from the exchange of angular momentum between the crust and the interior of the star. Recently, it was inferred that the moment of inertia of the crust of a neutron star is not sufficient to explain the observed glitches. Such estimates are presumed in Einstein's general relativity in describing the hydrostatic equilibrium of neutron stars. The crust of the neutron star has a spacetime curvature of 14 orders of magnitude larger than that probed in solar system tests. This makes gravity the weakest constrained physics input in the crust-related processes. We calculate the ratio of the crustal to the total moment of inertia of neutron stars in the scalar-tensor theory of gravity and the nonperturbative f (R )=R +a R2 gravity. We find for the former that the crust-to-core ratio of the moment of inertia does not change significantly from what is inferred in general relativity. For the latter, we find that the ratio increases significantly from what is inferred in general relativity in the case of high mass objects. Our results suggest that the glitch activity of pulsars may be used to probe gravity models, although the gravity models explored in this work are not appropriate candidates.

  5. Stringy Gravity: Solving the Dark Problems at `short' distance

    NASA Astrophysics Data System (ADS)

    Park, Jeong-Hyuck

    2018-01-01

    Dictated by Symmetry Principle, string theory predicts not General Relativity but its own gravity which assumes the entire closed string massless sector to be geometric and thus gravitational. In terms of R/(MG), i.e. the dimensionless radial variable normalized by mass, Stringy Gravity agrees with General Relativity toward infinity, but modifies it at short distance. At far short distance, gravitational force can be even repulsive. These may solve the dark matter and energy problems, as they arise essentially from small R/(MG) observations: long distance divided by much heavier mass. We address the pertinent differential geometry for Stringy Gravity, stringy Equivalence Principle, stringy geodesics and the minimal coupling to the Standard Model. We highlight the notion of `doubled-yet-gauged' coordinate system, in which a gauge orbit corresponds to a single physical point and proper distance is defined between two gauge orbits by a path integral.

  6. Tectonic escape in the evolution of the continental crust

    NASA Technical Reports Server (NTRS)

    Burke, K.; Sengor, C.

    1986-01-01

    The continental crust originated by processes similar to those operating today and continents consist of material most of which originated long ago in arc-systems that have later been modified, especially at Andean margins and in continental collisions where crustal thickening is common. Collision-related strike-slip motion is a general process in continental evolution. Because buoyant continental (or arc) material generally moves during collision toward a nearby oceanic margin where less buoyant lithosphere crops out, the process of major strike-slip dominated motion toward a 'free-face' is called 'tectonic escape'. Tectonic escape is and has been an element in continental evolution throughout recorded earth-history. It promotes: (1) rifting and the formation of rift-basins with thinning of thickened crust; (2) pervasive strike-slip faulting late in orogenic history which breaks up mountain belts across strike and may juxtapose unrelated sectors in cross-section; (3) localized compressional mountains and related foreland-trough basins.

  7. Thin-shell wormholes in rainbow gravity

    NASA Astrophysics Data System (ADS)

    Amirabi, Z.; Halilsoy, M.; Mazharimousavi, S. Habib

    2018-03-01

    At the Planck scale of length ˜10‑35 m where the energy is comparable with the Planck energy, the quantum gravity corrections to the classical background spacetime results in gravity’s rainbow or rainbow gravity. In this modified theory of gravity, geometry depends on the energy of the test particle used to probe the spacetime, such that in the low energy limit, it yields the standard general relativity. In this work, we study the thin-shell wormholes in the spherically symmetric rainbow gravity. We find the corresponding properties in terms of the rainbow functions which are essential in the rainbow gravity and the stability of such thin-shell wormholes are investigated. Particularly, it will be shown that there are exact solutions in which high energy particles crossing the throat will encounter less amount of total exotic matter. This may be used as an advantage over general relativity to reduce the amount of exotic matter.

  8. Barriers to diagnosing and managing hypertension - a qualitative study in Australian general practice.

    PubMed

    Howes, Faline; Hansen, Emily; Williams, Danielle; Nelson, Mark

    2010-07-01

    Elevated blood pressure (BP) is a major modifiable risk factor. However hypertension still remains underdiagnosed, untreated or suboptimally treated. This study aimed to identify and explore barriers to initiating medication and treating elevated BP to target levels in the general practice setting. Six focus groups involving 30 clinicians were audio recorded, transcribed in full and analysed for common emerging themes using an iterative thematic analysis. After making the decision to commence treatment, medication initiation was relatively straightforward. Clinical uncertainty about true underlying BP, distrust of measurement technology, and distrust of the evidence underpinning hypertension management were expressed. Patient age, gender and comorbidity influenced treatment strategy. Related themes included perceived patient attitude, clinical inertia, and patient centred care. Systems issues included lack of resources and lack of time. The management of an asymptomatic chronic disease within a patient centred, encounter based primary care context can be challenging.

  9. From density to interface fluctuations: The origin of wavelength dependence in surface tension

    NASA Astrophysics Data System (ADS)

    Hiester, Thorsten

    2008-12-01

    The height-height correlation function for a fluctuating interface between two coexisting bulk phases is derived by means of general equilibrium properties of the corresponding density-density correlation function. A wavelength-dependent surface tension γ(q) can be defined and expressed in terms of the direct correlation function c(r,r') , the equilibrium density profile ρ0(r) , and an operator which relates density to surface configurations. Neither the concept of an effective interface Hamiltonian nor the difference in pressure is needed to determine the general structure of the height-height correlations or γ(q) , respectively. This result generalizes the Mecke-Dietrich surface tension γMD(q) [Phys. Rev. E 59, 6766 (1999)] and modifies recently published criticism concerning γMD(q) [Tarazona, Checa, and Chacón, Phys. Rev. Lett. 99, 196101 (2007)].

  10. Method and apparatus for large motor control

    DOEpatents

    Rose, Chris R [Santa Fe, NM; Nelson, Ronald O [White Rock, NM

    2003-08-12

    Apparatus and method for providing digital signal processing method for controlling the speed and phase of a motor involves inputting a reference signal having a frequency and relative phase indicative of a time based signal; modifying the reference signal to introduce a slew-rate limited portion of each cycle of the reference signal; inputting a feedback signal having a frequency and relative phase indicative of the operation of said motor; modifying the feedback signal to introduce a slew-rate limited portion of each cycle of the feedback signal; analyzing the modified reference signal and the modified feedback signal to determine the frequency of the modified reference signal and of the modified feedback signal and said relative phase between said modified reference signal and said modified feedback signal; and outputting control signals to the motor for adjusting said speed and phase of the motor based on the frequency determination and determination of the relative phase.

  11. Hope as a Psychological Factor Affecting Quality of Life in Patients With Psoriasis.

    PubMed

    Szramka-Pawlak, Beata; Hornowska, Elżbieta; Walkowiak, Hanna; Zaba, Ryszard

    2014-01-01

    Clinical observations and medical reports indicate that psoriasis has a tremendous impact on patients' lives, lowering their quality in many important areas. However, the vast majority of research deals only with health-related issues. This study aimed to compare the general quality of life of psoriasis patients and healthy volunteers by examining psychological variables thought to modify the quality of life. 42 patients with psoriasis and 42 healthy volunteers matched for gender, age and education level were tested. Flanagan Quality of Life Scale was used to evaluate general quality of life. Basic hope level was assessed with Basic Hope Inventory. Trait hope was estimated using Trait Hope Scale. Psoriasis Area Severity Index was used to assess the severity of the disease. Psoriasis patients have a significantly lower overall quality of life ( p  = 0.05), modified by Physical and Material Well-being ( p  = 0.01), Personal Development and Fulfillment ( p  = 0.03), and Recreation ( p  = 0.04). They also have lower levels of trait hope ( p  = 0.04) and its agency component ( p  = 0.01). There were moderate, negative significant correlations with basic hope and such components of quality of life as Physical and Material Well-being ( p  = 0.03, r  = - 0.34) and Relations with other People ( p  = 0.02, r  = - 0.35). These results support the hypothesis of a reduced general quality of life and trait hope in psoriatics. Thus, psychological help for people suffering from dermatological disorders might be as important as medical intervention. Basic hope can be treated as a resource in coping with these disorders and trait hope as a resource conducive to well-being.

  12. Evolution of the equations of dynamics of the Universe: From Friedmann to the present day

    NASA Astrophysics Data System (ADS)

    Soloviev, V. O.

    2017-05-01

    Celebrating the centenary of general relativity theory, we must recall that Friedmann's discovery of the equations of evolution of the Universe became the strongest prediction of this theory. These equations currently remain the foundation of modern cosmology. Nevertheless, data from new observations stimulate a search for modified theories of gravitation. We discuss cosmological aspects of theories with two dynamical metrics and theories of massive gravity, one of which was developed by Logunov and his coworkers.

  13. Foam, Foam-resin composite and method of making a foam-resin composite

    NASA Technical Reports Server (NTRS)

    MacArthur, Doug E. (Inventor); Cranston, John A. (Inventor)

    1995-01-01

    This invention relates to a foam, a foam-resin composite and a method of making foam-resin composites. The foam set forth in this invention comprises a urethane modified polyisocyanurate derived from an aromatic amino polyol and a polyether polyol. In addition to the polyisocyanurate foam, the composite of this invention further contains a resin layer, wherein the resin may be epoxy, bismaleimide, or phenolic resin. Such resins generally require cure or post-cure temperatures of at least 350.degree. F.

  14. JWFront: Wavefronts and Light Cones for Kerr Spacetimes

    NASA Astrophysics Data System (ADS)

    Frutos Alfaro, Francisco; Grave, Frank; Müller, Thomas; Adis, Daria

    2015-04-01

    JWFront visualizes wavefronts and light cones in general relativity. The interactive front-end allows users to enter the initial position values and choose the values for mass and angular momentum per unit mass. The wavefront animations are available in 2D and 3D; the light cones are visualized using the coordinate systems (t, x, y) or (t, z, x). JWFront can be easily modified to simulate wavefronts and light cones for other spacetime by providing the Christoffel symbols in the program.

  15. Jeans instability of rotating magnetized dusty plasma

    NASA Astrophysics Data System (ADS)

    Sharma, S.; Sutar, D. L.; Kumar, V.; Pensia, R. K.

    2018-05-01

    It has been shown that rotation has to play a predominant important role in the formation of many astrophysical objects and the stability of molecular clouds. In this paper the theoretical investigation of the presence of rotation in the magnetized dusty plasma. The general dispersion relation is obtained normal mode analysis technique, and we found the Alfven mode is modified due to the presence of rotation and magnetic field. The graphical presentation shows that rotation and Alfven wave velocity have a stabilizing in the system.

  16. Resolving the issue of branched Hamiltonian in modified Lanczos-Lovelock gravity

    NASA Astrophysics Data System (ADS)

    Ruz, Soumendranath; Mandal, Ranajit; Debnath, Subhra; Sanyal, Abhik Kumar

    2016-07-01

    The Hamiltonian constraint H_c = N{H} = 0, defines a diffeomorphic structure on spatial manifolds by the lapse function N in general theory of relativity. However, it is not manifest in Lanczos-Lovelock gravity, since the expression for velocity in terms of the momentum is multivalued. Thus the Hamiltonian is a branch function of momentum. Here we propose an extended theory of Lanczos-Lovelock gravity to construct a unique Hamiltonian in its minisuperspace version, which results in manifest diffeomorphic invariance and canonical quantization.

  17. Role of relativity in electron impact ionization

    NASA Astrophysics Data System (ADS)

    Saha, Bidhan C.; Basak, Arun K.; Alfaz Uddin, M.

    2006-03-01

    The recently modified MBELL parameters[1] are generalized in terms of nl quantum numbers and applied to few selective systems. We intend to describe the procedure and to report the excellent predictive role of this simple procedure[2]. [1] A. K. F. Haque, M. A. Uddin, A.K. Basak, K. R. Karim and B. C. Saha, Phys. Rev. A 76 (in press) [2] A. K. F. Haque, M. A. Uddin, A.K. Basak, K. R. Karim, B. C. Saha, and F. B. Malik, Phys. Rev. Lett (under consideration)

  18. Wormhole solutions in f(R) gravity satisfying energy conditions

    NASA Astrophysics Data System (ADS)

    Mazharimousavi, S. Habib; Halilsoy, M.

    2016-10-01

    Without reference to exotic sources construction of viable wormholes in Einstein’s general relativity remained ever a myth. With the advent of modified theories, however, specifically the f(R) theory, new hopes arose for the possibility of such objects. From this token, we construct traversable wormholes in f(R) theory supported by a fluid source which respects at least the weak energy conditions. We provide an example (Example 1) of asymptotically flat wormhole in f(R) gravity without ghosts.

  19. 46 CFR 52.01-50 - Fusible plugs (modifies A-19 through A-21).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Fusible plugs (modifies A-19 through A-21). 52.01-50 Section 52.01-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-50 Fusible plugs (modifies A-19 through A-21). (a) All...

  20. 46 CFR 52.01-50 - Fusible plugs (modifies A-19 through A-21).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Fusible plugs (modifies A-19 through A-21). 52.01-50 Section 52.01-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-50 Fusible plugs (modifies A-19 through A-21). (a) All...

  1. 46 CFR 52.01-50 - Fusible plugs (modifies A-19 through A-21).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Fusible plugs (modifies A-19 through A-21). 52.01-50 Section 52.01-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-50 Fusible plugs (modifies A-19 through A-21). (a) All...

  2. 46 CFR 52.01-50 - Fusible plugs (modifies A-19 through A-21).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Fusible plugs (modifies A-19 through A-21). 52.01-50 Section 52.01-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-50 Fusible plugs (modifies A-19 through A-21). (a) All...

  3. Chemical modification of wood

    Treesearch

    Roger M. Rowell

    2005-01-01

    The properties of any resource are, in general, a result of the chemistry of the components of that resource. In the case of wood, the cell wall polymers (cellulose, hemicelluloses, and lignin) are the components that, if modified, would change the properties of the resource. If the properties of the wood are modified, the performance of the modified wood would be...

  4. 47 CFR 1.113 - Action modified or set aside by person, panel, or board.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the action may modify or set it aside on its own motion. (b) Within 60 days after notice of any... 47 Telecommunication 1 2011-10-01 2011-10-01 false Action modified or set aside by person, panel... AND PROCEDURE General Rules of Practice and Procedure Reconsideration and Review of Actions Taken by...

  5. 47 CFR 1.113 - Action modified or set aside by person, panel, or board.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the action may modify or set it aside on its own motion. (b) Within 60 days after notice of any... 47 Telecommunication 1 2010-10-01 2010-10-01 false Action modified or set aside by person, panel... AND PROCEDURE General Rules of Practice and Procedure Reconsideration and Review of Actions Taken by...

  6. 46 CFR 54.01-10 - Steam-generating pressure vessels (modifies U-1(g)).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Steam-generating pressure vessels (modifies U-1(g)). 54... ENGINEERING PRESSURE VESSELS General Requirements § 54.01-10 Steam-generating pressure vessels (modifies U-1(g)). (a) Pressure vessels in which steam is generated are classed as “Unfired Steam Boilers” except as...

  7. Health effects after firing small arms comparing leaded and unleaded ammunition.

    PubMed

    Voie, Øyvind; Borander, Anne-Katrine; Sikkeland, Liv Ingunn Bjoner; Grahnstedt, Svein; Johnsen, Arnt; Danielsen, Tor Erik; Longva, Kjetil; Kongerud, Johny

    2014-12-01

    A number of Norwegian soldiers have reported health problems after live-fire training using the HK416 rifle. The objective of this study was to characterize gaseous and particulate emissions from three different types of ammunition, and record the health effects after exposure to emissions from live-firing. Fifty-five healthy, non-smoking men (mean age 40 years) were recruited and divided randomly into three groups, one for each type of ammunition. All subjects fired the HK416 rifle in a semi-airtight tent for 60 min using leaded ammunition, unleaded ammunition and modified unleaded ammunition. Gaseous and particulate emissions were monitored within the tent. The symptoms experienced by the subjects were recorded immediately after and the day after firing using a standardized questionnaire. The concentrations of particulate matter and copper exceeded their respective occupational exposure limits (eight hours per day, five days a week) by a factor of 3 and 27, respectively. Of the 55 subjects, 54 reported general and respiratory symptoms. The total number of symptoms reported was significantly higher among shooters using unleaded ammunition as compared with the use of leaded and modified unleaded ammunition. Copper was the substance that had the highest concentration relative to its toxicity. Although the general symptoms were found to be consistent with the development of metal fume fever, the respiratory symptoms indicated an irritant effect of the airways different from that seen in metal fume fever. More symptoms were reported when unleaded ammunition was used compared with leaded and modified unleaded ammunition.

  8. Cognitive modifiability of children with developmental disabilities: a multicentre study using Feuerstein's Instrumental Enrichment--Basic program.

    PubMed

    Kozulin, A; Lebeer, J; Madella-Noja, A; Gonzalez, F; Jeffrey, I; Rosenthal, N; Koslowsky, M

    2010-01-01

    The study aimed at exploring the effectiveness of cognitive intervention with the new "Instrumental Enrichment Basic" program (IE-basic), based on Feuerstein's theory of structural cognitive modifiability that contends that a child's cognitive functioning can be significantly modified through mediated learning intervention. The IE-basic progam is aimed at enhancing domain-general cognitive functioning in a number of areas (systematic perception, self-regulation abilities, conceptual vocabulary, planning, decoding emotions and social relations) as well as transferring learnt principles to daily life domains. Participants were children with DCD, CP, intellectual impairment of genetic origin, autistic spectrum disorder, ADHD or other learning disorders, with a mental age of 5-7 years, from Canada, Chile, Belgium, Italy and Israel. Children in the experimental groups (N=104) received 27-90 h of the program during 30-45 weeks; the comparison groups (N=72) received general occupational and sensory-motor therapy. Analysis of the pre- to post-test gain scores demonstrated significant (p<0.05) advantage of experimental over comparison groups in three WISC-R subtests ("Similarities", "Picture Completion", "Picture Arrangement") and Raven Coloured Matrices. Effect sizes ranged from 0.3 to 0.52. Results suggest that it is possible to improve cognitive functioning of children with developmental disability. No advantage was found for children with specific aetiology. Greater cognitive gains were demonstrated by children who received the program in an educational context where all teachers were committed to the principles of mediated learning. Copyright 2009 Elsevier Ltd. All rights reserved.

  9. Gravitational instability in isotropic MHD plasma waves

    NASA Astrophysics Data System (ADS)

    Cherkos, Alemayehu Mengesha

    2018-04-01

    The effect of compressive viscosity, thermal conductivity and radiative heat-loss functions on the gravitational instability of infinitely extended homogeneous MHD plasma has been investigated. By taking in account these parameters we developed the six-order dispersion relation for magnetohydrodynamic (MHD) waves propagating in a homogeneous and isotropic plasma. The general dispersion relation has been developed from set of linearized basic equations and solved analytically to analyse the conditions of instability and instability of self-gravitating plasma embedded in a constant magnetic field. Our result shows that the presence of viscosity and thermal conductivity in a strong magnetic field substantially modifies the fundamental Jeans criterion of gravitational instability.

  10. Relating transverse-momentum-dependent and collinear factorization theorems in a generalized formalism

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Collins, J.; Gamberg, L.; Prokudin, A.

    We construct an improved implementation for combining TMD factorization transverse- momentum-dependent (TMD) factorization and collinear factorization. TMD factorization is suit- able for low transverse momentum physics, while collinear factorization is suitable for high transverse momenta and for a cross section integrated over transverse momentum. The result is a modified version of the standard W + Y prescription traditionally used in the Collins-Soper-Sterman (CSS) formalism and related approaches. As a result, we further argue that questions regarding the shape and Q- dependence of the cross sections at lower Q are largely governed by the matching to the Y -term.

  11. Relating transverse-momentum-dependent and collinear factorization theorems in a generalized formalism

    DOE PAGES

    Collins, J.; Gamberg, L.; Prokudin, A.; ...

    2016-08-08

    We construct an improved implementation for combining TMD factorization transverse- momentum-dependent (TMD) factorization and collinear factorization. TMD factorization is suit- able for low transverse momentum physics, while collinear factorization is suitable for high transverse momenta and for a cross section integrated over transverse momentum. The result is a modified version of the standard W + Y prescription traditionally used in the Collins-Soper-Sterman (CSS) formalism and related approaches. As a result, we further argue that questions regarding the shape and Q- dependence of the cross sections at lower Q are largely governed by the matching to the Y -term.

  12. Statistical aspects of the Klein-Gordon oscillator in the frame work of GUP

    NASA Astrophysics Data System (ADS)

    Khosropour, B.

    2018-01-01

    Investigation in perturbative string theory and quantum gravity suggest that there is a measurable minimal length in nature. In this work, according to generalized uncertainty principle, we study the statistical characteristics of Klein-Gordon Oscillator (KLO). The modified energy spectrum of the KLO are obtained. The generalized thermodynamical quantities of the KLO such as partition function, mean energy and entropy are calculated by using the modified energy spectrum.

  13. School and community relations in North America: Creative tensions

    NASA Astrophysics Data System (ADS)

    Loughran, E.; Reed, H. B.

    1980-09-01

    School and community relations in North America reflect creative tensions between the conserving forces of schooling and the changing forces of community. During crisis periods community development needs may modify the school's focus on individual learner growth, but generally schools use the community to extend and enrich the traditional modes. School and community interactions are chiefly characterized by such settings as community schools, community education, adult education, home and school (PTA) associations, work-study programs, curriculum-community resource programs. Recent social forces are creating heightened tensions: cultural pluralism, reduced resources, Third World influences, international conflicts, personal alienation, population concerns, energy problems, community power issues. These forces are gradually shifting school and community concepts towards ones of education and community. Education goes well beyond schooling, including all agencies having an organized influence on community development: libraries, voluntary groups, unions, business, human service agencies, government units, as well as schools. This shift requires research to develop nonformal concepts and practices, along with formal pedagogy, to increase the positive impacts of educational networks on community, as well as individual, development. These new directions have not yet significantly modified the traditional meaning of school and community relations.

  14. Music mixing preferences of cochlear implant recipients: a pilot study.

    PubMed

    Buyens, Wim; van Dijk, Bas; Moonen, Marc; Wouters, Jan

    2014-05-01

    Music perception and appraisal are generally poor in cochlear implant recipients. Simple musical structures, lyrics that are easy to follow, and clear rhythm/beat have been reported among the top factors to enhance music enjoyment. The present study investigated the preference for modified relative instrument levels in music with normal-hearing and cochlear implant subjects. In experiment 1, test subjects were given a mixing console and multi-track recordings to determine their most enjoyable audio mix. In experiment 2, a preference rating experiment based on the preferred relative level settings in experiment 1 was performed. Experiment 1 was performed with four postlingually deafened cochlear implant subjects, experiment 2 with ten normal-hearing and ten cochlear implant subjects. A significant difference in preference rating was found between normal-hearing and cochlear implant subjects. The latter preferred an audio mix with larger vocals-to-instruments ratio. In addition, given an audio mix with clear vocals and attenuated instruments, cochlear implant subjects preferred the bass/drum track to be louder than the other instrument tracks. The original audio mix in real-world music might not be suitable for cochlear implant recipients. Modifying the relative instrument level settings potentially improves music enjoyment.

  15. Benefits and risks of ovarian function and reproduction for cancer development and prevention.

    PubMed

    Schindler, Adolf E

    2011-12-01

    Ovarian function and menstrual cycle disturbances, pregnancy, and reproductive medicine procedures can either increase gynecological cancer risk or prevent cancer development. For ovarian cancer development, there are two hypotheses, which are connected with ovulation and gonadotropin secretion. Most of the ovarian cancers seem to be derived from displaced ovarian surfice epithelial cells. One year of ovulatory cycles increases the ovarian cancer risk by 6%. Ovulation between 22 and 29 years of age causes the highest risk increase per year. In contrast, progesterone or progestins appear to create protection. Lifestyle can affect or modify ovarian cancer risk. Breast cancer risk is very much related to age of menarche and menopause, pregnancy, and breast feeding. All of which are related to ovarian function and progestogenic impact that translates either into breast cancer risk increase or decrease. This is modified by body mass index, physical activity, and lifestyle in general. The risk of endometrial cancer is most closely related to endogenous progesterone during the menstrual cycle and pregnancy or by exogenous progestogens as in oral contraceptives. These effects are progestogen dose and time dependent. Endometrial cancer risk can also be increased by estrogen-producing tumors or long-term estrogen treatment.

  16. Beyond δ: Tailoring marked statistics to reveal modified gravity

    NASA Astrophysics Data System (ADS)

    Valogiannis, Georgios; Bean, Rachel

    2018-01-01

    Models which attempt to explain the accelerated expansion of the universe through large-scale modifications to General Relativity (GR), must satisfy the stringent experimental constraints of GR in the solar system. Viable candidates invoke a “screening” mechanism, that dynamically suppresses deviations in high density environments, making their overall detection challenging even for ambitious future large-scale structure surveys. We present methods to efficiently simulate the non-linear properties of such theories, and consider how a series of statistics that reweight the density field to accentuate deviations from GR can be applied to enhance the overall signal-to-noise ratio in differentiating the models from GR. Our results demonstrate that the cosmic density field can yield additional, invaluable cosmological information, beyond the simple density power spectrum, that will enable surveys to more confidently discriminate between modified gravity models and ΛCDM.

  17. Causal properties of nonlinear gravitational waves in modified gravity

    NASA Astrophysics Data System (ADS)

    Suvorov, Arthur George; Melatos, Andrew

    2017-09-01

    Some exact, nonlinear, vacuum gravitational wave solutions are derived for certain polynomial f (R ) gravities. We show that the boundaries of the gravitational domain of dependence, associated with events in polynomial f (R ) gravity, are not null as they are in general relativity. The implication is that electromagnetic and gravitational causality separate into distinct notions in modified gravity, which may have observable astrophysical consequences. The linear theory predicts that tachyonic instabilities occur, when the quadratic coefficient a2 of the Taylor expansion of f (R ) is negative, while the exact, nonlinear, cylindrical wave solutions presented here can be superluminal for all values of a2. Anisotropic solutions are found, whose wave fronts trace out time- or spacelike hypersurfaces with complicated geometric properties. We show that the solutions exist in f (R ) theories that are consistent with Solar System and pulsar timing experiments.

  18. De Sitter and scaling solutions in a higher-order modified teleparallel theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Paliathanasis, Andronikos, E-mail: anpaliat@phys.uoa.gr

    The existence and the stability conditions for some exact relativistic solutions of special interest are studied in a higher-order modified teleparallel gravitational theory. The theory with the use of a Lagrange multiplier is equivalent with that of General Relativity with a minimally coupled noncanonical field. The conditions for the existence of de Sitter solutions and ideal gas solutions in the case of vacuum are studied as also the stability criteria. Furthermore, in the presence of matter the behaviour of scaling solutions is given. Finally, we discuss the degrees of freedom of the field equations and we reduce the field equationsmore » in an algebraic equation, where in order to demonstrate our result we show how this noncanonical scalar field can reproduce the Hubble function of Λ-cosmology.« less

  19. Empirical Investigation of a Model of Sexual Minority Specific and General Risk Factors for Intimate Partner Violence among Lesbian Women.

    PubMed

    Lewis, Robin J; Mason, Tyler B; Winstead, Barbara A; Kelley, Michelle L

    2017-01-01

    This study proposed and tested the first conceptual model of sexual minority specific (discrimination, internalized homophobia) and more general risk factors (perpetrator and partner alcohol use, anger, relationship satisfaction) for intimate partner violence among partnered lesbian women. Self-identified lesbian women ( N =1048) were recruited from online market research panels. Participants completed an online survey that included measures of minority stress, anger, alcohol use and alcohol-related problems, relationship satisfaction, psychological aggression, and physical violence. The model demonstrated good fit and significant links from sexual minority discrimination to internalized homophobia and anger, from internalized homophobia to anger and alcohol problems, and from alcohol problems to intimate partner violence. Partner alcohol use predicted partner physical violence. Relationship dissatisfaction was associated with physical violence via psychological aggression. Physical violence was bidirectional. Minority stress, anger, alcohol use and alcohol-related problems play an important role in perpetration of psychological aggression and physical violence in lesbian women's intimate partner relationships. The results of this study provide evidence of potentially modifiable sexual minority specific and more general risk factors for lesbian women's partner violence.

  20. Task-specific modulation of adult humans' tool preferences: number of choices and size of the problem.

    PubMed

    Silva, Kathleen M; Gross, Thomas J; Silva, Francisco J

    2015-03-01

    In two experiments, we examined the effect of modifications to the features of a stick-and-tube problem on the stick lengths that adult humans used to solve the problem. In Experiment 1, we examined whether people's tool preferences for retrieving an out-of-reach object in a tube might more closely resemble those reported with laboratory crows if people could modify a single stick to an ideal length to solve the problem. Contrary to when adult humans have selected a tool from a set of ten sticks, asking people to modify a single stick to retrieve an object did not generally result in a stick whose length was related to the object's distance. Consistent with the prior research, though, the working length of the stick was related to the object's distance. In Experiment 2, we examined the effect of increasing the scale of the stick-and-tube problem on people's tool preferences. Increasing the scale of the task influenced people to select relatively shorter tools than had selected in previous studies. Although the causal structures of the tasks used in the two experiments were identical, their results were not. This underscores the necessity of studying physical cognition in relation to a particular causal structure by using a variety of tasks and methods.

  1. Determination of the diagnostic value of the Modified Mallampati Score, Upper Lip Bite Test and Facial Angle in predicting difficult intubation: A prospective descriptive study.

    PubMed

    Mahmoodpoor, Ata; Soleimanpour, Hassan; Golzari, Samad Ej; Nejabatian, Arezoo; Pourlak, Tannaz; Amani, Masoumeh; Hajmohammadi, Saeed; Hosseinzadeh, Hamzeh; Esfanjani, Robab Mehdizadeh

    2017-02-01

    Difficult intubation is a significant cause of mortality and morbidity related to anesthesia. We decided to evaluate the value of Modified Mallampati Score, Upper Lip Bite Test and Facial Angle in the prediction of difficult intubation. In a prospective descriptive study, data from 132 patients who were candidates for elective maxillofacial surgeries under general anesthesia were gathered. Facial Angles were measured by a maxillofacial surgeon according to cephalometry. The Modified Mallampati Score and Upper Lip Bite Test were first measured by an anesthesiologist and then another anesthesiologist was assigned to record the Cormack and Lehane score during the intubation. Grades 3 and 4 were considered as difficult intubation. Sensitivity, specificity, positive predictive value, negative predictive value and Youden index were calculated for all tests. Difficult intubation was reported in 12% of the patients. Facial Angle≤82.5° can predict difficult intubation with 87.5% sensitivity and 88.8% specificity. Among the three tests, a high Modified Mallampati Score had the highest specificity (94.5%) and a high Modified Mallampati Score and Facial Angle (FA≤82.5°) had the highest sensitivity (87.5%). The highest NPV, sensitivity and Youden index were observed when using Facial Angle with the Modified Mallampati Score or with Upper Lip Bite Test. Facial Angle has a high sensitivity, NPV and Youden index for the prediction of difficult intubation, but the best result is achieved when Facial Angle is used in combination with either the Modified Mallampati Score or Upper Lip Bit Test. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Improving access for patients – a practice manager questionnaire

    PubMed Central

    Meade, James G; Brown, James S

    2006-01-01

    Background The administrative and professional consequences of access targets for general practices, as detailed in the new GMS contract, are unknown. This study researched the effect of implementing the access targets of the new GP contract on general practice appointment systems, and practice manager satisfaction in a UK primary health care setting. Methods A four-part postal questionnaire was administered. The questionnaire was modified from previously validated questionnaires and the findings compared with data obtained from the Western Health and Social Services Board (WHSSB) in N Ireland. Practice managers from the 59 general practices in the WHSSB responded to the questionnaire. Results There was a 94.9% response rate. Practice managers were generally satisfied with the introduction of access targets for patients. Some 57.1% of responding practices, most in deprived areas (Odds ratio 3.13 -95% CI 1.01 – 9.80, p = 0.0256) had modified their appointment systems. Less booking flexibility was reported among group practices (p = 0.006), urban practices (p < 0.001) and those with above average patient list sizes (p < 0.001). Receptionists had not received training in patient appointment management in a quarter of practices. Practices with smaller list sizes were more likely than larger ones to utilise nurses in seeing extra patients (p = 0.007) or to undertake triage procedures (p = 0.062). Conclusion The findings demonstrated the ability of general practices within the WHSSB to adjust to a demanding component of the new GP contract. Issues relating to the flexibility of patient appointment booking systems, receptionists' training and the development of the primary care nursing role were highlighted by the study. PMID:16784530

  3. Modeling zero-modified count and semicontinuous data in health services research Part 1: background and overview.

    PubMed

    Neelon, Brian; O'Malley, A James; Smith, Valerie A

    2016-11-30

    Health services data often contain a high proportion of zeros. In studies examining patient hospitalization rates, for instance, many patients will have no hospitalizations, resulting in a count of zero. When the number of zeros is greater or less than expected under a standard count model, the data are said to be zero modified relative to the standard model. A similar phenomenon arises with semicontinuous data, which are characterized by a spike at zero followed by a continuous distribution with positive support. When analyzing zero-modified count and semicontinuous data, flexible mixture distributions are often needed to accommodate both the excess zeros and the typically skewed distribution of nonzero values. Various models have been introduced over the past three decades to accommodate such data, including hurdle models, zero-inflated models, and two-part semicontinuous models. This tutorial describes recent modeling strategies for zero-modified count and semicontinuous data and highlights their role in health services research studies. Part 1 of the tutorial, presented here, provides a general overview of the topic. Part 2, appearing as a companion piece in this issue of Statistics in Medicine, discusses three case studies illustrating applications of the methods to health services research. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  4. Temperature rise in ion-leachable cements during setting reaction.

    PubMed

    Kanchanavasita, W; Pearson, G J; Anstice, H M

    1995-11-01

    Resin-modified ion-leachable cements have been developed for use as aesthetic restorative materials. Their apparent improved physical and handling properties can make them more attractive for use than conventional glass-ionomers. However, they contain monomers which are known to contract on polymerization and produce a polymerization exotherm. This study evaluated the temperature rise during setting and the rate of dimensional change of several ion-leachable materials. The resin-modified ion-leachable cements demonstrated greater temperature rises and higher rates of contraction than conventional materials. Generally, the behaviour of these resin-modified materials was similar to that of composite resins. However, some resin-modified cements produced a temperature rise of up to 20 degrees C during polymerization which was greater than that of the composite resin. This temperature rise must be taken into account when using the materials in direct contact with dentine in deep cavities without pulp protection. Longer irradiation time than the recommended 20 s did not significantly increase the maximum temperature rise but slightly extended the time before the temperature started to decline. The temperature of the environment had a significant effect on the rate of dimensional change in some materials. The rate of polymerization contraction of light-activated cements was directly related to the observed temperature rise.

  5. Generalized wave operators, weighted Killing fields, and perturbations of higher dimensional spacetimes

    NASA Astrophysics Data System (ADS)

    Araneda, Bernardo

    2018-04-01

    We present weighted covariant derivatives and wave operators for perturbations of certain algebraically special Einstein spacetimes in arbitrary dimensions, under which the Teukolsky and related equations become weighted wave equations. We show that the higher dimensional generalization of the principal null directions are weighted conformal Killing vectors with respect to the modified covariant derivative. We also introduce a modified Laplace–de Rham-like operator acting on tensor-valued differential forms, and show that the wave-like equations are, at the linear level, appropriate projections off shell of this operator acting on the curvature tensor; the projection tensors being made out of weighted conformal Killing–Yano tensors. We give off shell operator identities that map the Einstein and Maxwell equations into weighted scalar equations, and using adjoint operators we construct solutions of the original field equations in a compact form from solutions of the wave-like equations. We study the extreme and zero boost weight cases; extreme boost corresponding to perturbations of Kundt spacetimes (which includes near horizon geometries of extreme black holes), and zero boost to static black holes in arbitrary dimensions. In 4D our results apply to Einstein spacetimes of Petrov type D and make use of weighted Killing spinors.

  6. Symptoms in Response to Controlled Diesel Exhaust More Closely Reflect Exposure Perception Than True Exposure

    PubMed Central

    Carlsten, Chris; Oron, Assaf P.; Curtiss, Heidi; Jarvis, Sara; Daniell, William; Kaufman, Joel D.

    2013-01-01

    Background Diesel exhaust (DE) exposures are very common, yet exposure-related symptoms haven’t been rigorously examined. Objective Describe symptomatic responses to freshly generated and diluted DE and filtered air (FA) in a controlled human exposure setting; assess whether such responses are altered by perception of exposure. Methods 43 subjects participated within three double-blind crossover experiments to order-randomized DE exposure levels (FA and DE calibrated at 100 and/or 200 micrograms/m3 particulate matter of diameter less than 2.5 microns), and completed questionnaires regarding symptoms and dose perception. Results For a given symptom cluster, the majority of those exposed to moderate concentrations of diesel exhaust do not report such symptoms. The most commonly reported symptom cluster was of the nose (29%). Blinding to exposure is generally effective. Perceived exposure, rather than true exposure, is the dominant modifier of symptom reporting. Conclusion Controlled human exposure to moderate-dose diesel exhaust is associated with a range of mild symptoms, though the majority of individuals will not experience any given symptom. Blinding to DE exposure is generally effective. Perceived DE exposure, rather than true DE exposure, is the dominant modifier of symptom reporting. PMID:24358296

  7. 46 CFR 53.01-5 - Scope (modifies HG-100).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Scope (modifies HG-100). 53.01-5 Section 53.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING HEATING BOILERS General Requirements § 53.01-5 Scope (modifies HG-100). (a) The regulations in this part apply to steam heating boilers, hot water boilers (which include...

  8. 46 CFR 52.01-115 - Feedwater supply (modifies PG-61).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Feedwater supply (modifies PG-61). 52.01-115 Section 52.01-115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-115 Feedwater supply (modifies PG-61). Boiler feedwater supply must meet the requirements of PG-61 of section I of...

  9. 46 CFR 53.01-5 - Scope (modifies HG-100).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Scope (modifies HG-100). 53.01-5 Section 53.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING HEATING BOILERS General Requirements § 53.01-5 Scope (modifies HG-100). (a) The regulations in this part apply to steam heating boilers, hot water boilers (which include...

  10. 46 CFR 54.01-30 - Loadings (modifies UG-22).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Loadings (modifies UG-22). 54.01-30 Section 54.01-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS General Requirements § 54.01-30 Loadings (modifies UG-22). (a) The loadings for pressure vessels shall be as required by UG-22 of section VIII of the...

  11. 46 CFR 54.01-30 - Loadings (modifies UG-22).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Loadings (modifies UG-22). 54.01-30 Section 54.01-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS General Requirements § 54.01-30 Loadings (modifies UG-22). (a) The loadings for pressure vessels shall be as required by UG-22 of section VIII of the...

  12. 46 CFR 53.01-5 - Scope (modifies HG-100).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Scope (modifies HG-100). 53.01-5 Section 53.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING HEATING BOILERS General Requirements § 53.01-5 Scope (modifies HG-100). (a) The regulations in this part apply to steam heating boilers, hot water boilers (which include...

  13. 46 CFR 52.01-115 - Feedwater supply (modifies PG-61).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Feedwater supply (modifies PG-61). 52.01-115 Section 52.01-115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-115 Feedwater supply (modifies PG-61). Boiler feedwater supply must meet the requirements of PG-61 of section I of...

  14. 46 CFR 53.01-5 - Scope (modifies HG-100).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Scope (modifies HG-100). 53.01-5 Section 53.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING HEATING BOILERS General Requirements § 53.01-5 Scope (modifies HG-100). (a) The regulations in this part apply to steam heating boilers, hot water boilers (which include...

  15. 46 CFR 52.01-115 - Feedwater supply (modifies PG-61).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Feedwater supply (modifies PG-61). 52.01-115 Section 52.01-115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-115 Feedwater supply (modifies PG-61). Boiler feedwater supply must meet the requirements of PG-61 of section I of...

  16. 46 CFR 54.01-30 - Loadings (modifies UG-22).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Loadings (modifies UG-22). 54.01-30 Section 54.01-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS General Requirements § 54.01-30 Loadings (modifies UG-22). (a) The loadings for pressure vessels shall be as required by UG-22 of section VIII of the...

  17. 46 CFR 52.01-115 - Feedwater supply (modifies PG-61).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Feedwater supply (modifies PG-61). 52.01-115 Section 52.01-115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-115 Feedwater supply (modifies PG-61). Boiler feedwater supply must meet the requirements of PG-61 of section I of...

  18. 46 CFR 54.01-30 - Loadings (modifies UG-22).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Loadings (modifies UG-22). 54.01-30 Section 54.01-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS General Requirements § 54.01-30 Loadings (modifies UG-22). (a) The loadings for pressure vessels shall be as required by UG-22 of section VIII of the...

  19. 46 CFR 52.01-115 - Feedwater supply (modifies PG-61).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Feedwater supply (modifies PG-61). 52.01-115 Section 52.01-115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-115 Feedwater supply (modifies PG-61). Boiler feedwater supply must meet the requirements of PG-61 of section I of...

  20. 46 CFR 54.01-30 - Loadings (modifies UG-22).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Loadings (modifies UG-22). 54.01-30 Section 54.01-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS General Requirements § 54.01-30 Loadings (modifies UG-22). (a) The loadings for pressure vessels shall be as required by UG-22 of section VIII of the...

  1. 46 CFR 53.01-5 - Scope (modifies HG-100).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Scope (modifies HG-100). 53.01-5 Section 53.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING HEATING BOILERS General Requirements § 53.01-5 Scope (modifies HG-100). (a) The regulations in this part apply to steam heating boilers, hot water boilers (which include...

  2. 46 CFR 54.15-13 - Rupture disks (modifies UG-127).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...: (1) Comply with the general provisions of § 54.15-5 except as noted otherwise in this section; (2... 46 Shipping 2 2011-10-01 2011-10-01 false Rupture disks (modifies UG-127). 54.15-13 Section 54.15... VESSELS Pressure-Relief Devices § 54.15-13 Rupture disks (modifies UG-127). (a) Paragraph UG-127 of...

  3. 46 CFR 54.15-13 - Rupture disks (modifies UG-127).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: (1) Comply with the general provisions of § 54.15-5 except as noted otherwise in this section; (2... 46 Shipping 2 2010-10-01 2010-10-01 false Rupture disks (modifies UG-127). 54.15-13 Section 54.15... VESSELS Pressure-Relief Devices § 54.15-13 Rupture disks (modifies UG-127). (a) Paragraph UG-127 of...

  4. 46 CFR 54.15-13 - Rupture disks (modifies UG-127).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...: (1) Comply with the general provisions of § 54.15-5 except as noted otherwise in this section; (2... 46 Shipping 2 2013-10-01 2013-10-01 false Rupture disks (modifies UG-127). 54.15-13 Section 54.15... VESSELS Pressure-Relief Devices § 54.15-13 Rupture disks (modifies UG-127). (a) Paragraph UG-127 of...

  5. 46 CFR 54.15-13 - Rupture disks (modifies UG-127).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...: (1) Comply with the general provisions of § 54.15-5 except as noted otherwise in this section; (2... 46 Shipping 2 2014-10-01 2014-10-01 false Rupture disks (modifies UG-127). 54.15-13 Section 54.15... VESSELS Pressure-Relief Devices § 54.15-13 Rupture disks (modifies UG-127). (a) Paragraph UG-127 of...

  6. 46 CFR 54.15-13 - Rupture disks (modifies UG-127).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...: (1) Comply with the general provisions of § 54.15-5 except as noted otherwise in this section; (2... 46 Shipping 2 2012-10-01 2012-10-01 false Rupture disks (modifies UG-127). 54.15-13 Section 54.15... VESSELS Pressure-Relief Devices § 54.15-13 Rupture disks (modifies UG-127). (a) Paragraph UG-127 of...

  7. JRC GMO-Amplicons: a collection of nucleic acid sequences related to genetically modified organisms

    PubMed Central

    Petrillo, Mauro; Angers-Loustau, Alexandre; Henriksson, Peter; Bonfini, Laura; Patak, Alex; Kreysa, Joachim

    2015-01-01

    The DNA target sequence is the key element in designing detection methods for genetically modified organisms (GMOs). Unfortunately this information is frequently lacking, especially for unauthorized GMOs. In addition, patent sequences are generally poorly annotated, buried in complex and extensive documentation and hard to link to the corresponding GM event. Here, we present the JRC GMO-Amplicons, a database of amplicons collected by screening public nucleotide sequence databanks by in silico determination of PCR amplification with reference methods for GMO analysis. The European Union Reference Laboratory for Genetically Modified Food and Feed (EU-RL GMFF) provides these methods in the GMOMETHODS database to support enforcement of EU legislation and GM food/feed control. The JRC GMO-Amplicons database is composed of more than 240 000 amplicons, which can be easily accessed and screened through a web interface. To our knowledge, this is the first attempt at pooling and collecting publicly available sequences related to GMOs in food and feed. The JRC GMO-Amplicons supports control laboratories in the design and assessment of GMO methods, providing inter-alia in silico prediction of primers specificity and GM targets coverage. The new tool can assist the laboratories in the analysis of complex issues, such as the detection and identification of unauthorized GMOs. Notably, the JRC GMO-Amplicons database allows the retrieval and characterization of GMO-related sequences included in patents documentation. Finally, it can help annotating poorly described GM sequences and identifying new relevant GMO-related sequences in public databases. The JRC GMO-Amplicons is freely accessible through a web-based portal that is hosted on the EU-RL GMFF website. Database URL: http://gmo-crl.jrc.ec.europa.eu/jrcgmoamplicons/ PMID:26424080

  8. JRC GMO-Amplicons: a collection of nucleic acid sequences related to genetically modified organisms.

    PubMed

    Petrillo, Mauro; Angers-Loustau, Alexandre; Henriksson, Peter; Bonfini, Laura; Patak, Alex; Kreysa, Joachim

    2015-01-01

    The DNA target sequence is the key element in designing detection methods for genetically modified organisms (GMOs). Unfortunately this information is frequently lacking, especially for unauthorized GMOs. In addition, patent sequences are generally poorly annotated, buried in complex and extensive documentation and hard to link to the corresponding GM event. Here, we present the JRC GMO-Amplicons, a database of amplicons collected by screening public nucleotide sequence databanks by in silico determination of PCR amplification with reference methods for GMO analysis. The European Union Reference Laboratory for Genetically Modified Food and Feed (EU-RL GMFF) provides these methods in the GMOMETHODS database to support enforcement of EU legislation and GM food/feed control. The JRC GMO-Amplicons database is composed of more than 240 000 amplicons, which can be easily accessed and screened through a web interface. To our knowledge, this is the first attempt at pooling and collecting publicly available sequences related to GMOs in food and feed. The JRC GMO-Amplicons supports control laboratories in the design and assessment of GMO methods, providing inter-alia in silico prediction of primers specificity and GM targets coverage. The new tool can assist the laboratories in the analysis of complex issues, such as the detection and identification of unauthorized GMOs. Notably, the JRC GMO-Amplicons database allows the retrieval and characterization of GMO-related sequences included in patents documentation. Finally, it can help annotating poorly described GM sequences and identifying new relevant GMO-related sequences in public databases. The JRC GMO-Amplicons is freely accessible through a web-based portal that is hosted on the EU-RL GMFF website. Database URL: http://gmo-crl.jrc.ec.europa.eu/jrcgmoamplicons/. © The Author(s) 2015. Published by Oxford University Press.

  9. Higher Intelligence Is Associated with Less Task-Related Brain Network Reconfiguration

    PubMed Central

    Cole, Michael W.

    2016-01-01

    The human brain is able to exceed modern computers on multiple computational demands (e.g., language, planning) using a small fraction of the energy. The mystery of how the brain can be so efficient is compounded by recent evidence that all brain regions are constantly active as they interact in so-called resting-state networks (RSNs). To investigate the brain's ability to process complex cognitive demands efficiently, we compared functional connectivity (FC) during rest and multiple highly distinct tasks. We found previously that RSNs are present during a wide variety of tasks and that tasks only minimally modify FC patterns throughout the brain. Here, we tested the hypothesis that, although subtle, these task-evoked FC updates from rest nonetheless contribute strongly to behavioral performance. One might expect that larger changes in FC reflect optimization of networks for the task at hand, improving behavioral performance. Alternatively, smaller changes in FC could reflect optimization for efficient (i.e., small) network updates, reducing processing demands to improve behavioral performance. We found across three task domains that high-performing individuals exhibited more efficient brain connectivity updates in the form of smaller changes in functional network architecture between rest and task. These smaller changes suggest that individuals with an optimized intrinsic network configuration for domain-general task performance experience more efficient network updates generally. Confirming this, network update efficiency correlated with general intelligence. The brain's reconfiguration efficiency therefore appears to be a key feature contributing to both its network dynamics and general cognitive ability. SIGNIFICANCE STATEMENT The brain's network configuration varies based on current task demands. For example, functional brain connections are organized in one way when one is resting quietly but in another way if one is asked to make a decision. We found that the efficiency of these updates in brain network organization is positively related to general intelligence, the ability to perform a wide variety of cognitively challenging tasks well. Specifically, we found that brain network configuration at rest was already closer to a wide variety of task configurations in intelligent individuals. This suggests that the ability to modify network connectivity efficiently when task demands change is a hallmark of high intelligence. PMID:27535904

  10. Mars Pathfinder Landing Site: Evidence for a Change in Wind Regime and Climate from Lander and Orbiter Data

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Kraft, M. D.; Kuzmin, R. O.; Bridges, N. T.

    1999-01-01

    Surface features related to the wind are observed in data from the Mars Pathfinder lander and from orbit by the Viking Orbiter and Mars Global Surveyor missions. Features seen from the surface include wind tails associated with small rocks, barchanoid duneforms, ripplelike patterns, and ventifact flutes cut into some rocks. Features seen from orbit include wind tails associated with impact craters, ridges inferred to be duneforms, and modified crater rims interpreted to have been eroded and mantled by windblown material. The orientations of these features show two prevailing directions, one inferred to represent winds from the northeast which is consistent with strongest winds predicted by a general circulation model to occur during the Martian northern winter under current conditions, and a second wind pattern oriented approx. 90 degrees to the first. This latter wind could be from the W-NW or from the E-SE and was responsible for cutting the ventifacts and modifying the crater rims. The two wind regimes could reflect a change in climate related to Mars' obliquity or some other, unknown factor. Regardless of the cause, the MPF area has been subjected to a complex pattern of winds and supply of small particles, in which the original surface formed by sedimentary processes from Tiu and Ares Vallis events has been modified by repeated burial and exhumation.

  11. Matter bispectrum beyond Horndeski theories

    NASA Astrophysics Data System (ADS)

    Hirano, Shin'ichi; Kobayashi, Tsutomu; Tashiro, Hiroyuki; Yokoyama, Shuichiro

    2018-05-01

    The Horndeski scalar-tensor theory and its recent extensions allow nonlinear derivative interactions of the scalar degree of freedom. We study the matter bispectrum of large scale structure as a probe of these modified gravity theories, focusing in particular on the effect of the terms that newly appear in the so-called "beyond Horndeski" theories. We derive the second-order solution for the matter density perturbations and find that the interactions beyond Horndeski lead to a new time-dependent coefficient in the second-order kernel which differs in general from the standard value of general relativity and the Horndeski theory. This can deform the matter bispectrum at the folded triangle configurations (k1+k2=k3 ), while it is never possible within the Horndeski theory.

  12. Generalizing on best practices in image processing: a model for promoting research integrity: Commentary on: Avoiding twisted pixels: ethical guidelines for the appropriate use and manipulation of scientific digital images.

    PubMed

    Benos, Dale J; Vollmer, Sara H

    2010-12-01

    Modifying images for scientific publication is now quick and easy due to changes in technology. This has created a need for new image processing guidelines and attitudes, such as those offered to the research community by Doug Cromey (Cromey 2010). We suggest that related changes in technology have simplified the task of detecting misconduct for journal editors as well as researchers, and that this simplification has caused a shift in the responsibility for reporting misconduct. We also argue that the concept of best practices in image processing can serve as a general model for education in best practices in research.

  13. Contemporary research on parenting: conceptual, methodological, and translational issues.

    PubMed

    Power, Thomas G; Sleddens, Ester F C; Berge, Jerica; Connell, Lauren; Govig, Bert; Hennessy, Erin; Liggett, Leanne; Mallan, Kimberley; Santa Maria, Diane; Odoms-Young, Angela; St George, Sara M

    2013-08-01

    Researchers over the last decade have documented the association between general parenting style and numerous factors related to childhood obesity (e.g., children's eating behaviors, physical activity, and weight status). Many recent childhood obesity prevention programs are family focused and designed to modify parenting behaviors thought to contribute to childhood obesity risk. This article presents a brief consideration of conceptual, methodological, and translational issues that can inform future research on the role of parenting in childhood obesity. They include: (1) General versus domain specific parenting styles and practices; (2) the role of ethnicity and culture; (3) assessing bidirectional influences; (4) broadening assessments beyond the immediate family; (5) novel approaches to parenting measurement; and (6) designing effective interventions. Numerous directions for future research are offered.

  14. Modified relativistic dynamics

    NASA Astrophysics Data System (ADS)

    Qadir, Asghar; Lee, Hyung Won; Kim, Kyoung Yee

    One of the major problems in Cosmology is the fact that there is no good candidate of dark matter in the Standard Model of Particle Physics or any experimentally supported modifications of it. At the same time, one of the major problems of General Relativity is that it cannot be unified with Quantum Theory. Here, we present a program to see if there is not a common source of both problems. The idea is that an interaction term between matter fields and the gravitational field in the total Lagrangian, analogous to that for Electromagnetism, could possibly provide the dynamical effect for which the dark matter is postulated, on the one hand and a Quantum-Field Theory (QFT) incorporating Gravity, that does not have unmanageable divergences, on the other. One could first check that the modified relativistic dynamics, if fitted for the dark matter in individual galaxies fits also for systems and clusters of galaxies, at all scales. If there is no problem with the explanation of the dynamics usually explained by dark matter at all scales, we could check if it leads to a workable QFT of Relativity.

  15. Physical and psychosocial prerequisites of functioning in relation to work ability and general subjective well-being among office workers.

    PubMed

    Sjögren-Rönkä, Tuulikki; Ojanen, Markku T; Leskinen, Esko K; Tmustalampi, Sirpa; Mälkiä, Esko A

    2002-06-01

    The purpose of the study was to investigate the physical and psychological prerequisites of functioning, as well as the social environment at work and personal factors, in relation to work ability and general subjective well-being in a group of office workers. The study was a descriptive cross-sectional investigation, using path analysis, of office workers. The subjects comprised 88 volunteers, 24 men and 64 women, from the same workplace [mean age 45.7 (SD 8.6) years]. The independent variables were measured using psychosocial and physical questionnaires and physical measurements. The first dependent variable, work ability, was measured by a work ability index. The second dependent variable, general subjective well-being, was assessed by life satisfaction and meaning of life. The variables were structured according to a modified version of the International Classification of Functioning, Disability and Health. Forward flexion of the spine, intensity of musculoskeletal symptoms, self-confidence, and mental stress at work explained 58% of work ability and had indirect effects on general subjective well-being. Self-confidence, mood, and work ability had a direct effect on general subjective well-being. The model developed explained 68% of general subjective well-being. Age played a significant role in this study population. The prerequisites of physical functioning are important in maintaining work ability, particularly among aging workers, and psychological prerequisites of functioning are of even greater importance in maintaining general subjective well-being.

  16. The effect of spin induced magnetization on Jeans instability of viscous and resistive quantum plasma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sharma, Prerana, E-mail: preranaiitd@rediffmail.com; Chhajlani, R. K.

    2014-03-15

    The effect of spin induced magnetization and electrical resistivity incorporating the viscosity of the medium is examined on the Jeans instability of quantum magnetoplasma. Formulation of the system is done by using the quantum magnetohydrodynamic model. The analysis of the problem is carried out by normal mode analysis theory. The general dispersion relation is derived from set of perturbed equations to analyse the growth rate and condition of self-gravitational Jeans instability. To discuss the influence of resistivity, magnetization, and viscosity parameters on Jeans instability, the general dispersion relation is reduced for both transverse and longitudinal mode of propagations. In themore » case of transverse propagation, the gravitating mode is found to be affected by the viscosity, magnetization, resistivity, and magnetic field strength whereas Jeans criterion of instability is modified by the magnetization and quantum parameter. In the longitudinal mode of propagation, the gravitating mode is found to be modified due to the viscosity and quantum correction in which the Jeans condition of instability is influenced only by quantum parameter. The other non-gravitating Alfven mode in this direction is affected by finite electrical resistivity, spin induced magnetization, and viscosity. The numerical study for the growth rate of Jeans instability is carried out for both in the transverse and longitudinal direction of propagation to the magnetic field. The effect of various parameters on the growth rate of Jeans instability in quantum plasma is analysed.« less

  17. Permeability estimations and frictional flow features passing through porous media comprised of structured microbeads

    NASA Astrophysics Data System (ADS)

    Shin, C.

    2017-12-01

    Permeability estimation has been extensively researched in diverse fields; however, methods that suitably consider varying geometries and changes within the flow region, for example, hydraulic fracture closing for several years, are yet to be developed. Therefore, in the present study a new permeability estimation method is presented based on the generalized Darcy's friction flow relation, in particular, by examining frictional flow parameters and characteristics of their variations. For this examination, computational fluid dynamics (CFD) simulations of simple hydraulic fractures filled with five layers of structured microbeads and accompanied by geometry changes and flow transitions are performed. Consequently, it was checked whether the main structures and shapes of each flow path are preserved, even for geometry variations within porous media. However, the scarcity and discontinuity of streamlines increase dramatically in the transient- and turbulent-flow regions. The quantitative and analytic examinations of the frictional flow features were also performed. Accordingly, the modified frictional flow parameters were successfully presented as similarity parameters of porous flows. In conclusion, the generalized Darcy's friction flow relation and friction equivalent permeability (FEP) equation were both modified using the similarity parameters. For verification, the FEP values of the other aperture models were estimated and then it was checked whether they agreed well with the original permeability values. Ultimately, the proposed and verified method is expected to efficiently estimate permeability variations in porous media with changing geometric factors and flow regions, including such instances as hydraulic fracture closings.

  18. Soy Intake Modifies the Relation Between Urinary Bisphenol A Concentrations and Pregnancy Outcomes Among Women Undergoing Assisted Reproduction

    PubMed Central

    Mínguez-Alarcón, Lidia; Chiu, Yu-Han; Gaskins, Audrey J.; Souter, Irene; Williams, Paige L.; Calafat, Antonia M.; Hauser, Russ

    2016-01-01

    Context: Experimental data in rodents suggest that the adverse reproductive health effects of bisphenol A (BPA) can be modified by intake of soy phytoestrogens. Whether the same is true in humans is not known. Objective: The purpose of this study was to evaluate whether soy consumption modifies the relation between urinary BPA levels and infertility treatment outcomes among women undergoing assisted reproduction. Setting: The study was conducted in a fertility center in a teaching hospital. Design: We evaluated 239 women enrolled between 2007 and 2012 in the Environment and Reproductive Health (EARTH) Study, a prospective cohort study, who underwent 347 in vitro fertilization (IVF) cycles. Participants completed a baseline questionnaire and provided up to 2 urine samples in each treatment cycle before oocyte retrieval. IVF outcomes were abstracted from electronic medical records. We used generalized linear mixed models with interaction terms to evaluate whether the association between urinary BPA concentrations and IVF outcomes was modified by soy intake. Main Outcome Measure: Live birth rates per initiated treatment cycle were measured. Results: Soy food consumption modified the association of urinary BPA concentration with live birth rates (P for interaction = .01). Among women who did not consume soy foods, the adjusted live birth rates per initiated cycle in increasing quartiles of cycle-specific urinary BPA concentrations were 54%, 35%, 31%, and 17% (P for trend = .03). The corresponding live birth rates among women reporting pretreatment consumption of soy foods were 38%, 42%, 47%, and 49% (P for trend = 0.35). A similar pattern was found for implantation (P for interaction = .02) and clinical pregnancy rates (P for interaction = .03) per initiated cycle, where urinary BPA was inversely related to these outcomes among women not consuming soy foods but unrelated to them among soy consumers. Conclusion: Soy food intake may protect against the adverse reproductive effects of BPA. As these findings represent the first report suggesting a potential interaction between soy and BPA in humans, they should be further evaluated in other populations. PMID:26815879

  19. Pain and emotional distress among substance-use patients beginning treatment relative to a representative comparison group

    PubMed Central

    Wiest, Katharina L.; Colditz, Jason B.; Carr, Kathryn; Asphaug, Victoria J.; McCarty, Dennis; Pilkonis, Paul A.

    2014-01-01

    Objectives: A secondary analysis assessed health-related quality of life characteristics (i.e. anxiety, depression, fatigue, and types of pain) among patients entering substance-use treatment, and identified characteristics specific to treatment modalities relative to a representative comparison group. Methods: As part of a larger alcohol bank assessment, substance-use patients (n=406) beginning methadone treatment (n=170) or other outpatient treatment (n=236) and a comparison group representative of the general population (n=1000) completed a survey measuring anxiety, depression, fatigue, pain interference, and pain in the last 7 days. Previous studies lacked comparable and concurrent assessments across these three groups. Results: Patients entering substance-use treatment had relatively high levels of emotional distress and poorer health-related quality of life relative to the general population. Among treatment modalities, patients beginning methadone treatment reported the highest levels of pain interference and pain behavior and the poorest physical functioning. Prior to the potentially modifying effects of methadone maintenance, patients beginning agonist therapy reported the greatest levels of compromised quality of life. Conclusion: These data present the magnitude of differences in health-related quality of life characteristics between treatment and comparison groups using the same assessment rubric and may help inform the design and timing of treatment modalities, thereby enhancing treatment efficacy for patients. PMID:25275876

  20. A Generalized National Planning Approach for Admission Capacity in Higher Education: A Nonlinear Integer Goal Programming Model with a Novel Differential Evolution Algorithm

    PubMed Central

    El-Qulity, Said Ali; Mohamed, Ali Wagdy

    2016-01-01

    This paper proposes a nonlinear integer goal programming model (NIGPM) for solving the general problem of admission capacity planning in a country as a whole. The work aims to satisfy most of the required key objectives of a country related to the enrollment problem for higher education. The system general outlines are developed along with the solution methodology for application to the time horizon in a given plan. The up-to-date data for Saudi Arabia is used as a case study and a novel evolutionary algorithm based on modified differential evolution (DE) algorithm is used to solve the complexity of the NIGPM generated for different goal priorities. The experimental results presented in this paper show their effectiveness in solving the admission capacity for higher education in terms of final solution quality and robustness. PMID:26819583

  1. A Generalized National Planning Approach for Admission Capacity in Higher Education: A Nonlinear Integer Goal Programming Model with a Novel Differential Evolution Algorithm.

    PubMed

    El-Qulity, Said Ali; Mohamed, Ali Wagdy

    2016-01-01

    This paper proposes a nonlinear integer goal programming model (NIGPM) for solving the general problem of admission capacity planning in a country as a whole. The work aims to satisfy most of the required key objectives of a country related to the enrollment problem for higher education. The system general outlines are developed along with the solution methodology for application to the time horizon in a given plan. The up-to-date data for Saudi Arabia is used as a case study and a novel evolutionary algorithm based on modified differential evolution (DE) algorithm is used to solve the complexity of the NIGPM generated for different goal priorities. The experimental results presented in this paper show their effectiveness in solving the admission capacity for higher education in terms of final solution quality and robustness.

  2. The SMM Model as a Boundary Value Problem Using the Discrete Diffusion Equation

    NASA Technical Reports Server (NTRS)

    Campbell, Joel

    2007-01-01

    A generalized single step stepwise mutation model (SMM) is developed that takes into account an arbitrary initial state to a certain partial difference equation. This is solved in both the approximate continuum limit and the more exact discrete form. A time evolution model is developed for Y DNA or mtDNA that takes into account the reflective boundary modeling minimum microsatellite length and the original difference equation. A comparison is made between the more widely known continuum Gaussian model and a discrete model, which is based on modified Bessel functions of the first kind. A correction is made to the SMM model for the probability that two individuals are related that takes into account a reflecting boundary modeling minimum microsatellite length. This method is generalized to take into account the general n-step model and exact solutions are found. A new model is proposed for the step distribution.

  3. The SMM model as a boundary value problem using the discrete diffusion equation.

    PubMed

    Campbell, Joel

    2007-12-01

    A generalized single-step stepwise mutation model (SMM) is developed that takes into account an arbitrary initial state to a certain partial difference equation. This is solved in both the approximate continuum limit and the more exact discrete form. A time evolution model is developed for Y DNA or mtDNA that takes into account the reflective boundary modeling minimum microsatellite length and the original difference equation. A comparison is made between the more widely known continuum Gaussian model and a discrete model, which is based on modified Bessel functions of the first kind. A correction is made to the SMM model for the probability that two individuals are related that takes into account a reflecting boundary modeling minimum microsatellite length. This method is generalized to take into account the general n-step model and exact solutions are found. A new model is proposed for the step distribution.

  4. Prevalence of modifiable cardiovascular risk factors among tea garden and general population in Dibrugarh, Assam, India.

    PubMed

    Mahanta, Tulika G; Joshi, Rajnish; Mahanta, Bhupendra N; Xavier, Denis

    2013-09-01

    Risk factors for cardiovascular disease (CVD) are multifactorial. Previous research has reported a high prevalence of CVD risk factors in tea-garden workers. This study was conducted to assess prevalence and level of modifiable cardiovascular risk factors among tea-garden and general population in Dibrugarh, Assam. A community-based cross-sectional study using the World Health Organization's (WHO) Stepwise methodology was conducted in Dibrugarh District of Assam. A multistep random sampling was done to include adults aged 35 years and above, with an intended equal sampling from tea-garden and general population. INTERHEART modifiable non-laboratory based risk score was estimated. Salt consumption was estimated using questionnaire-based methods in both subgroups. A total of 2826 individuals participated in the study (1231 [43.6%] tea-garden workers; 1595 [56.4%] general population). Tobacco consumption was higher in tea-garden workers as compared with general population (85.2% vs. 41.7% (p < 0.0001). Mean daily per-capita salt consumption was also significantly higher among tea-garden workers (29.60 vs. 22.89 g, p = 0.0001). Overall prevalence of hypertension was similar (44.4% vs. 45.2%), but among those who had hypertension, prevalence of undiagnosed hypertension was higher in tea-garden workers (82.8% vs. 74.4%, p < 0.0001). Tea-garden workers had lower BMI, were more physically active, and had a lower prevalence of diabetes mellitus and metabolic syndrome. Their INTERHEART modifiable risk score was also lower (1.44 [2.5] vs. 1.79 [2.8], p = 0.001). High prevalence of modifiable risk factors like tobacco consumption, high salt intake and high prevalence of hypertension indicates the need for early implementation of preventive actions in this population. Copyright © 2013 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

  5. Which modifiable health risks are associated with changes in productivity costs?

    PubMed

    Kirkham, Heather S; Clark, Bobby L; Bolas, Cheryl A; Lewis, Geraint Hywel; Jackson, Allison S; Fisher, Don; Duncan, Ian

    2015-02-01

    The purpose of this retrospective, longitudinal study was to assess longitudinal associations between modifiable health risks and workplace absenteeism and presenteeism and to estimate lost productivity costs. Across the 4-year study period (2007-2010), 17,089 unique employees from a large US computer manufacturer with a highly technical workforce completed at least 1 health risk assessment. Generalized estimating equation models were used to estimate the mean population-level absenteeism and presenteeism for 11 modifiable health risks and adjust for 9 sociodemographic and employment-related factors. Because patient age was highly correlated with several other variables, the analysis was stratified by age (<45 vs. ≥45 years). For all ages, poor emotional health, inadequate exercise, tobacco use, and having a body mass index (BMI) greater than 35 (all P<.05) were consistently associated with both absenteeism and presenteeism. Having a BMI over 35 and poor emotional health were associated with the largest impact in absenteeism (0.46 days) and presenteeism (4.03 days), respectively. Younger and older workers had similar associations between health risks and presenteeism; however, hypertension, blood sugar, inadequate exercise, and alcohol were associated (P⋜.01) with greater absenteeism among older but not younger workers. The results suggest that productivity loss is strongly related to emotional health and obesity-related health risks (eg, BMI, exercise) but differs by age. These findings could help prioritize preventive health programs offered by employers at their worksite health centers. Given the aging of the US workforce, keeping older workers healthy and productive will be crucial to remaining competitive in the global economy. (Population Health Management 2015;18:30-38).

  6. On entropic uncertainty relations in the presence of a minimal length

    NASA Astrophysics Data System (ADS)

    Rastegin, Alexey E.

    2017-07-01

    Entropic uncertainty relations for the position and momentum within the generalized uncertainty principle are examined. Studies of this principle are motivated by the existence of a minimal observable length. Then the position and momentum operators satisfy the modified commutation relation, for which more than one algebraic representation is known. One of them is described by auxiliary momentum so that the momentum and coordinate wave functions are connected by the Fourier transform. However, the probability density functions of the physically true and auxiliary momenta are different. As the corresponding entropies differ, known entropic uncertainty relations are changed. Using differential Shannon entropies, we give a state-dependent formulation with correction term. State-independent uncertainty relations are obtained in terms of the Rényi entropies and the Tsallis entropies with binning. Such relations allow one to take into account a finiteness of measurement resolution.

  7. Selective attention in anxiety: distraction and enhancement in visual search.

    PubMed

    Rinck, Mike; Becker, Eni S; Kellermann, Jana; Roth, Walton T

    2003-01-01

    According to cognitive models of anxiety, anxiety patients exhibit an attentional bias towards threat, manifested as greater distractibility by threat stimuli and enhanced detection of them. Both phenomena were studied in two experiments, using a modified visual search task, in which participants were asked to find single target words (GAD-related, speech-related, neutral, or positive) hidden in matrices made up of distractor words (also GAD-related, speech-related, neutral, or positive). Generalized anxiety disorder (GAD) patients, social phobia (SP) patients afraid of giving speeches, and healthy controls participated in the visual search task. GAD patients were slowed by GAD-related distractor words but did not show statistically reliable evidence of enhanced detection of GAD-related target words. SP patients showed neither distraction nor enhancement effects. These results extend previous findings of attentional biases observed with other experimental paradigms. Copyright 2003 Wiley-Liss, Inc.

  8. 46 CFR 52.01-135 - Inspection and tests (modifies PG-90 through PG-100).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Inspection and tests (modifies PG-90 through PG-100). 52.01-135 Section 52.01-135 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-135 Inspection and tests (modifies PG-90 through PG-100). (a) Requirements. Inspection and test...

  9. 46 CFR 52.01-105 - Piping, valves and fittings (modifies PG-58 and PG-59).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Piping, valves and fittings (modifies PG-58 and PG-59). 52.01-105 Section 52.01-105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-105 Piping, valves and fittings (modifies PG-58 and PG-59). (a) Boiler external piping within...

  10. 46 CFR 52.01-140 - Certification by stamping (modifies PG-104 through PG-113).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Certification by stamping (modifies PG-104 through PG-113). 52.01-140 Section 52.01-140 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-140 Certification by stamping (modifies PG-104 through PG-113). (a) All boilers built in...

  11. 46 CFR 52.01-135 - Inspection and tests (modifies PG-90 through PG-100).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Inspection and tests (modifies PG-90 through PG-100). 52.01-135 Section 52.01-135 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-135 Inspection and tests (modifies PG-90 through PG-100). (a) Requirements. Inspection and test...

  12. 46 CFR 52.01-140 - Certification by stamping (modifies PG-104 through PG-113).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Certification by stamping (modifies PG-104 through PG-113). 52.01-140 Section 52.01-140 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-140 Certification by stamping (modifies PG-104 through PG-113). (a) All boilers built in...

  13. 46 CFR 52.01-145 - Manufacturers' data report forms (modifies PG-112 and PG-113).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Manufacturers' data report forms (modifies PG-112 and PG-113). 52.01-145 Section 52.01-145 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-145 Manufacturers' data report forms (modifies PG-112 and PG-113). The manufacturers'...

  14. 46 CFR 52.01-145 - Manufacturers' data report forms (modifies PG-112 and PG-113).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Manufacturers' data report forms (modifies PG-112 and PG-113). 52.01-145 Section 52.01-145 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-145 Manufacturers' data report forms (modifies PG-112 and PG-113). The manufacturers'...

  15. 46 CFR 52.01-145 - Manufacturers' data report forms (modifies PG-112 and PG-113).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Manufacturers' data report forms (modifies PG-112 and PG-113). 52.01-145 Section 52.01-145 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-145 Manufacturers' data report forms (modifies PG-112 and PG-113). The manufacturers'...

  16. 46 CFR 52.01-105 - Piping, valves and fittings (modifies PG-58 and PG-59).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Piping, valves and fittings (modifies PG-58 and PG-59). 52.01-105 Section 52.01-105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-105 Piping, valves and fittings (modifies PG-58 and PG-59). (a) Boiler external piping within...

  17. 46 CFR 52.01-140 - Certification by stamping (modifies PG-104 through PG-113).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Certification by stamping (modifies PG-104 through PG-113). 52.01-140 Section 52.01-140 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-140 Certification by stamping (modifies PG-104 through PG-113). (a) All boilers built in...

  18. 46 CFR 52.01-140 - Certification by stamping (modifies PG-104 through PG-113).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Certification by stamping (modifies PG-104 through PG-113). 52.01-140 Section 52.01-140 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-140 Certification by stamping (modifies PG-104 through PG-113). (a) All boilers built in...

  19. 46 CFR 52.01-135 - Inspection and tests (modifies PG-90 through PG-100).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Inspection and tests (modifies PG-90 through PG-100). 52.01-135 Section 52.01-135 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-135 Inspection and tests (modifies PG-90 through PG-100). (a) Requirements. Inspection and test...

  20. 46 CFR 52.01-145 - Manufacturers' data report forms (modifies PG-112 and PG-113).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Manufacturers' data report forms (modifies PG-112 and PG-113). 52.01-145 Section 52.01-145 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-145 Manufacturers' data report forms (modifies PG-112 and PG-113). The manufacturers'...

  1. 46 CFR 52.01-105 - Piping, valves and fittings (modifies PG-58 and PG-59).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Piping, valves and fittings (modifies PG-58 and PG-59). 52.01-105 Section 52.01-105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-105 Piping, valves and fittings (modifies PG-58 and PG-59). (a) Boiler external piping within...

  2. 46 CFR 52.01-90 - Materials (modifies PG-5 through PG-13).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Materials (modifies PG-5 through PG-13). 52.01-90 Section 52.01-90 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-90 Materials (modifies PG-5 through PG-13). (a) Material subject to stress due to pressure must conform to...

  3. 46 CFR 52.01-90 - Materials (modifies PG-5 through PG-13).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Materials (modifies PG-5 through PG-13). 52.01-90 Section 52.01-90 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-90 Materials (modifies PG-5 through PG-13). (a) Material subject to stress due to pressure must conform to...

  4. 46 CFR 52.01-140 - Certification by stamping (modifies PG-104 through PG-113).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Certification by stamping (modifies PG-104 through PG-113). 52.01-140 Section 52.01-140 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-140 Certification by stamping (modifies PG-104 through PG-113). (a) All boilers built in...

  5. 46 CFR 52.01-135 - Inspection and tests (modifies PG-90 through PG-100).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Inspection and tests (modifies PG-90 through PG-100). 52.01-135 Section 52.01-135 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-135 Inspection and tests (modifies PG-90 through PG-100). (a) Requirements. Inspection and test...

  6. 46 CFR 52.01-145 - Manufacturers' data report forms (modifies PG-112 and PG-113).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Manufacturers' data report forms (modifies PG-112 and PG-113). 52.01-145 Section 52.01-145 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-145 Manufacturers' data report forms (modifies PG-112 and PG-113). The manufacturers'...

  7. 46 CFR 52.01-90 - Materials (modifies PG-5 through PG-13).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Materials (modifies PG-5 through PG-13). 52.01-90 Section 52.01-90 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-90 Materials (modifies PG-5 through PG-13). (a) Material subject to stress due to pressure must conform to...

  8. Association of risk factors with temporomandibular disorders in the Northern Finland Birth Cohort 1966.

    PubMed

    Jussila, Päivi; Knuutila, Jarno; Salmela, Sampo; Näpänkangas, Ritva; Päkkilä, Jari; Pirttiniemi, Pertti; Raustia, Aune

    2018-06-19

    To investigate the association between risk factors and pain-related symptoms and clinical signs of temporomandibular disorders (TMD) in Northern Finland Birth Cohort (NFBC) 1966. A total of 1962 subjects (1050 women, 912 men) attended the follow-up study. The questionnaires included the subjects' background information concerning living conditions and general health, socioeconomic factors, and dental health. The clinical examination was performed using the modified protocol of Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) presented at the International Association for Dental Research (IADR) Conference in 2010. Cross-tabulation, a chi-square test and Fisher's exact test were used to analyze differences between groups. Female gender showed statistically significant association with symptoms and signs of TMD, while marital status, living conditions, and socioeconomic group showed no association. A strong association was found between self-reported health condition as well as general health problems [i.e. depression, migraine, fibromyalgia (FM), gastrointestinal diseases] and TMD pain-related symptoms and pain on palpation in the masticatory muscles and TMJs. In conclusion, general health problems and female gender had a strong association with pain-related symptoms and clinical signs of TMD. These findings are important to take into account when diagnosing and treating TMD patients. Conversely to earlier presented results, no statistically significant association was shown here between marital status, living conditions or socioeconomic group and pain-related symptoms and clinical signs of TMD.

  9. Einstein's Theory Fights off Challengers

    NASA Astrophysics Data System (ADS)

    2010-04-01

    Two new and independent studies have put Einstein's General Theory of Relativity to the test like never before. These results, made using NASA's Chandra X-ray Observatory, show Einstein's theory is still the best game in town. Each team of scientists took advantage of extensive Chandra observations of galaxy clusters, the largest objects in the Universe bound together by gravity. One result undercuts a rival gravity model to General Relativity, while the other shows that Einstein's theory works over a vast range of times and distances across the cosmos. The first finding significantly weakens a competitor to General Relativity known as "f(R) gravity". "If General Relativity were the heavyweight boxing champion, this other theory was hoping to be the upstart contender," said Fabian Schmidt of the California Institute of Technology in Pasadena, who led the study. "Our work shows that the chances of its upsetting the champ are very slim." In recent years, physicists have turned their attention to competing theories to General Relativity as a possible explanation for the accelerated expansion of the universe. Currently, the most popular explanation for the acceleration is the so-called cosmological constant, which can be understood as energy that exists in empty space. This energy is referred to as dark energy to emphasize that it cannot be directly detected. In the f(R) theory, the cosmic acceleration comes not from an exotic form of energy but from a modification of the gravitational force. The modified force also affects the rate at which small enhancements of matter can grow over the eons to become massive clusters of galaxies, opening up the possibility of a sensitive test of the theory. Schmidt and colleagues used mass estimates of 49 galaxy clusters in the local universe from Chandra observations, and compared them with theoretical model predictions and studies of supernovas, the cosmic microwave background, and the large-scale distribution of galaxies. They found no evidence that gravity is different from General Relativity on scales larger than 130 million light years. This limit corresponds to a hundred-fold improvement on the bounds of the modified gravitational force's range that can be set without using the cluster data. "This is the strongest ever constraint set on an alternative to General Relativity on such large distance scales," said Schmidt. "Our results show that we can probe gravity stringently on cosmological scales by using observations of galaxy clusters." The reason for this dramatic improvement in constraints can be traced to the greatly enhanced gravitational forces acting in clusters as opposed to the universal background expansion of the universe. The cluster-growth technique also promises to be a good probe of other modified gravity scenarios, such as models motivated by higher-dimensional theories and string theory. A second, independent study also bolsters General Relativity by directly testing it across cosmological distances and times. Up until now, General Relativity had been verified only using experiments from laboratory to Solar System scales, leaving the door open to the possibility that General Relativity breaks down on much larger scales. To probe this question, a group at Stanford University compared Chandra observations of how rapidly galaxy clusters have grown over time to the predictions of General Relativity. The result is nearly complete agreement between observation and theory. "Einstein's theory succeeds again, this time in calculating how many massive clusters have formed under gravity's pull over the last five billion years," said David Rapetti of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) at Stanford University and SLAC National Accelerator Laboratory, who led the new study. "Excitingly and reassuringly, our results are the most robust consistency test of General Relativity yet carried out on cosmological scales." Rapetti and his colleagues based their results on a sample of 238 clusters detected across the whole sky by the now-defunct ROSAT X-ray telescope. These data were enhanced by detailed mass measurements for 71 distant clusters using Chandra, and 23 relatively nearby clusters using ROSAT, and combined with studies of supernovas, the cosmic microwave background, the distribution of galaxies and distance estimates to galaxy clusters. Galaxy clusters are important objects in the quest to understand the Universe as a whole. Because the observations of the masses of galaxy clusters are directly sensitive to the properties of gravity, they provide crucial information. Other techniques such as observations of supernovas or the distribution of galaxies measure cosmic distances, which depend only on the expansion rate of the universe. In contrast, the cluster technique used by Rapetti and his colleagues measure in addition the growth rate of the cosmic structure, as driven by gravity. "Cosmic acceleration represents a great challenge to our modern understanding of physics," said Rapetti's co-author Adam Mantz of NASA's Goddard Space Flight Center in Maryland. "Measurements of acceleration have highlighted how little we know about gravity at cosmic scales, but we're now starting to push back our ignorance." The paper by Fabian Schmidt was published in Physics Review D, Volume 80 in October 2009 and is co-authored by Alexey Vikhlinin of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and Wayne Hu of the University of Chicago, Illinois. The paper by David Rapetti was recently accepted for publication in the Monthly Notices of the Royal Astronomical Society and is co-authored by Mantz, Steve Allen of KIPAC at Stanford and Harald Ebeling of the Institute for Astronomy in Hawaii. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. More information, including images and other multimedia, can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

  10. Overview of latex modified concrete overlays : final report.

    DOT National Transportation Integrated Search

    1984-01-01

    Twelve bridges with latex modified concrete (LMC) overlays ranging in age from new to 13 years were studied and their general condition found to be good. The half-cell and chloride data were inconclusive because background data were not available for...

  11. Gaseous modification of MCrAlY coatings

    DOEpatents

    Vance, Steven J.; Goedjen, John G.; Sabol, Stephen M.; Sloan, Kelly M.

    2000-01-01

    The present invention generally describes methods for modifying MCrAlY coatings by using gaseous carburization, gaseous nitriding or gaseous carbonitriding. The modified MCrAlY coatings are useful in thermal barrier coating systems, which may be used in gas turbine engines.

  12. Extrasolar planets as a probe of modified gravity

    NASA Astrophysics Data System (ADS)

    Vargas dos Santos, Marcelo; Mota, David F.

    2017-06-01

    We propose a new method to test modified gravity theories, taking advantage of the available data on extrasolar planets. We computed the deviations from the Kepler third law and use that to constrain gravity theories beyond General Relativity. We investigate gravity models which incorporate three screening mechanisms: the Chameleon, the Symmetron and the Vainshtein. We find that data from exoplanets orbits are very sensitive to the screening mechanisms putting strong constraints in the parameter space for the Chameleon models and the Symmetron, complementary and competitive to other methods, like interferometers and solar system. With the constraints on Vainshtein we are able to work beyond the hypothesis that the crossover scale is of the same order of magnitude than the Hubble radius rc ∼ H0-1, which makes the screening work automatically, testing how strong this hypothesis is and the viability of other scales.

  13. Improving the crashworthiness of general aviation aircraft by crash injury investigations.

    PubMed

    Kirkham, W R

    1982-04-01

    An aircraft accident investigation program correlates injuries to occupants with the severity of impacts and structural changes in the crash. Findings brought to the attention of aircraft manufacturers have led to specific aircraft being made more crash-worthy. The finding of a failure in a shoulder harness attachment led to the strengthening of the attachment brace. The way a shoulder harness was joined to a lapbelt was modified following a noted failure. The finding of fractures of lapbelt and shoulder harness cable tiedowns led to the use of stronger cables and modification of the installation. Other findings resulted in a shoulder strap guide being placed on an inertia reel and a side-mounted seat being modified. Described also are three seat-related features which, although meeting FAA standards, during the dynamics of a crash may lack desirable energy attenuation. These findings illustrate the value of aircraft crash injury correlations.

  14. Modified circular velocity law

    NASA Astrophysics Data System (ADS)

    Djeghloul, Nazim

    2018-05-01

    A modified circular velocity law is presented for a test body orbiting around a spherically symmetric mass. This law exhibits a distance scale parameter and allows to recover both usual Newtonian behaviour for lower distances and a constant velocity limit at large scale. Application to the Galaxy predicts the known behaviour and also leads to a galactic mass in accordance with the measured visible stellar mass so that additional dark matter inside the Galaxy can be avoided. It is also shown that this circular velocity law can be embedded in a geometrical description of spacetime within the standard general relativity framework upon relaxing the usual asymptotic flatness condition. This formulation allows to redefine the introduced Newtonian scale limit in term of the central mass exclusively. Moreover, a satisfactory answer to the galactic escape speed problem can be provided indicating the possibility that one can also get rid of dark matter halo outside the Galaxy.

  15. Remote tropical and sub-tropical responses to Amazon deforestation

    NASA Astrophysics Data System (ADS)

    Badger, Andrew M.; Dirmeyer, Paul A.

    2016-05-01

    Replacing natural vegetation with realistic tropical crops over the Amazon region in a global Earth system model impacts vertical transport of heat and moisture, modifying the interaction between the atmospheric boundary layer and the free atmosphere. Vertical velocity is decreased over a majority of the Amazon region, shifting the ascending branch and modifying the seasonality of the Hadley circulation over the Atlantic and eastern Pacific oceans. Using a simple model that relates circulation changes to heating anomalies and generalizing the upper-atmosphere temperature response to deforestation, agreement is found between the response in the fully-coupled model and the simple solution. These changes to the large-scale dynamics significantly impact precipitation in several remote regions, namely sub-Saharan Africa, Mexico, the southwestern United States and extratropical South America, suggesting non-local climate repercussions for large-scale land use changes in the tropics are possible.

  16. Stefan-Maxwell Relations and Heat Flux with Anisotropic Transport Coefficients for Ionized Gases in a Magnetic Field with Application to the Problem of Ambipolar Diffusion

    NASA Astrophysics Data System (ADS)

    Kolesnichenko, A. V.; Marov, M. Ya.

    2018-01-01

    The defining relations for the thermodynamic diffusion and heat fluxes in a multicomponent, partially ionized gas mixture in an external electromagnetic field have been obtained by the methods of the kinetic theory. Generalized Stefan-Maxwell relations and algebraic equations for anisotropic transport coefficients (the multicomponent diffusion, thermal diffusion, electric and thermoelectric conductivity coefficients as well as the thermal diffusion ratios) associated with diffusion-thermal processes have been derived. The defining second-order equations are derived by the Chapman-Enskog procedure using Sonine polynomial expansions. The modified Stefan-Maxwell relations are used for the description of ambipolar diffusion in the Earth's ionospheric plasma (in the F region) composed of electrons, ions of many species, and neutral particles in a strong electromagnetic field.

  17. Quantum fluctuation theorems and generalized measurements during the force protocol.

    PubMed

    Watanabe, Gentaro; Venkatesh, B Prasanna; Talkner, Peter; Campisi, Michele; Hänggi, Peter

    2014-03-01

    Generalized measurements of an observable performed on a quantum system during a force protocol are investigated and conditions that guarantee the validity of the Jarzynski equality and the Crooks relation are formulated. In agreement with previous studies by M. Campisi, P. Talkner, and P. Hänggi [Phys. Rev. Lett. 105, 140601 (2010); Phys. Rev. E 83, 041114 (2011)], we find that these fluctuation relations are satisfied for projective measurements; however, for generalized measurements special conditions on the operators determining the measurements need to be met. For the Jarzynski equality to hold, the measurement operators of the forward protocol must be normalized in a particular way. The Crooks relation additionally entails that the backward and forward measurement operators depend on each other. Yet, quite some freedom is left as to how the two sets of operators are interrelated. This ambiguity is removed if one considers selective measurements, which are specified by a joint probability density function of work and measurement results of the considered observable. We find that the respective forward and backward joint probabilities satisfy the Crooks relation only if the measurement operators of the forward and backward protocols are the time-reversed adjoints of each other. In this case, the work probability density function conditioned on the measurement result satisfies a modified Crooks relation. The modification appears as a protocol-dependent factor that can be expressed by the information gained by the measurements during the forward and backward protocols. Finally, detailed fluctuation theorems with an arbitrary number of intervening measurements are obtained.

  18. Nonsingular rainbow universes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Awad, Adel; Ali, Ahmed Farag; Majumder, Barun, E-mail: aawad@zewailcity.edu.eg, E-mail: ahmed.ali@fsc.bu.edu.eg, E-mail: barunbasanta@iitgn.ac.in

    2013-10-01

    In this work, we study FRW cosmologies in the context of gravity rainbow. We discuss the general conditions for having a nonsingular FRW cosmology in gravity rainbow. We propose that gravity rainbow functions can be fixed using two known modified dispersion relation (MDR), which have been proposed in literature. The first MDR was introduced by Amelino-Camelia, et el. in [9] and the second was introduced by Magueijo and Smolin in [24]. Studying these FRW-like cosmologies, after fixing the gravity rainbow functions, leads to nonsingular solutions which can be expressed in exact forms.

  19. Happiness and job satisfaction in a casino-dominated economy.

    PubMed

    Zeng, Zhonglu; Forrest, David; McHale, Ian G

    2013-09-01

    Proposals for casinos usually focus on numbers of jobs without considering their quality. We surveyed 1,506 Macau residents, modelling happiness and job satisfaction. Being employed is shown to be important for 'happiness'. But job attributes also matter, confirming the work domain as influential on wellbeing. Casino employees report similar happiness as others. However, despite relatively high pay, they report low overall job satisfaction. The particular aspects of their jobs that they rated generally negatively tended to be those inherent in casino employment rather than easily modifiable by managerial action.

  20. Jeans instability of magnetized quantum plasma: Effect of viscosity, rotation and finite Larmor radius corrections

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jain, Shweta, E-mail: jshweta09@gmail.com; Sharma, Prerana; Chhajlani, R. K.

    2015-07-31

    The Jeans instability of self-gravitating quantum plasma is examined considering the effects of viscosity, finite Larmor radius (FLR) corrections and rotation. The analysis is done by normal mode analysis theory with the help of relevant linearized perturbation equations of the problem. The general dispersion relation is obtained using the quantum magneto hydrodynamic model. The modified condition of Jeans instability is obtained and the numerical calculations have been performed to show the effects of various parameters on the growth rate of Jeans instability.

  1. Supertrace formulae for nonlinearly realized supersymmetry

    NASA Astrophysics Data System (ADS)

    Murli, Divyanshu; Yamada, Yusuke

    2018-04-01

    We derive the general supertrace formula for a system with N chiral superfields and one nilpotent chiral superfield in global and local supersymmetry. The nilpotent multiplet is realized by taking the scalar-decoupling limit of a chiral superfield breaking supersymmetry spontaneously. As we show, however, the modified formula is not simply related to the scalar-decoupling limit of the supertrace in linearly-realized supersymmetry. We also show that the supertrace formula reduces to that of a linearly realized supersymmetric theory with a decoupled sGoldstino if the Goldstino is the fermion in the nilpotent multiplet.

  2. Sources Approved for Coverage under the SQCS General Permit in Region 8

    EPA Pesticide Factsheets

    The sources on Indian country reservation lands that the Region 8 has approved for coverage under the General Air Quality Permit for New and Modified Minor Source Stone Quarrying, Crushing, and Screening Facilities in Indian Country (SQCS General Permit).

  3. Environmental Strategies of Affect Regulation and Their Associations With Subjective Well-Being

    PubMed Central

    Korpela, Kalevi M.; Pasanen, Tytti; Repo, Veera; Hartig, Terry; Staats, Henk; Mason, Michael; Alves, Susana; Fornara, Ferdinando; Marks, Tony; Saini, Sunil; Scopelliti, Massimiliano; Soares, Ana L.; Stigsdotter, Ulrika K.; Ward Thompson, Catharine

    2018-01-01

    Environmental strategies of affect regulation refer to the use of natural and urban socio-physical settings in the service of regulation. We investigated the perceived use and efficacy of environmental strategies for regulation of general affect and sadness, considering them in relation to other affect regulation strategies and to subjective well-being. Participants from Australia, Finland, Germany, Great Britain, Italy, India, the Netherlands, Portugal, and Sweden (N = 507) evaluated the frequency of use and perceived efficacy of affect regulation strategies using a modified version of the Measure of Affect Regulation Styles (MARS). The internet survey also included the Satisfaction with Life Scale (SWLS), emotional well-being items from the RAND 36-Item Health Survey, and a single-item measure of perceived general health. Environmental regulation formed a separate factor of affect regulation in the exploratory structural equation models (ESEM). Although no relations of environmental strategies with emotional well-being were found, both the perceived frequency of use and efficacy of environmental strategies were positively related to perceived health. Moreover, the perceived efficacy of environmental strategies was positively related to life satisfaction in regulating sadness. The results encourage more explicit treatment of environmental strategies in research on affect regulation. PMID:29720955

  4. The role of airborne mineral dusts in human disease

    USGS Publications Warehouse

    Morman, Suzette A.; Plumlee, Geoffrey S.

    2013-01-01

    Exposure to fine particulate matter (PM) is generally acknowledged to increase risk for human morbidity and mortality. However, particulate matter (PM) research has generally examined anthropogenic (industry and combustion by-products) sources with few studies considering contributions from geogenic PM (produced from the Earth by natural processes, e.g., volcanic ash, windborne ash from wildfires, and mineral dusts) or geoanthropogenic PM (produced from natural sources by processes that are modified or enhanced by human activities, e.g., dusts from lakebeds dried by human removal of water, dusts produced from areas that have undergone desertification as a result of human practices). Globally, public health concerns are mounting, related to potential increases in dust emission from climate related changes such as desertification and the associated long range as well as local health effects. Recent epidemiological studies have identified associations between far-traveled dusts from primary sources and increased morbidity and mortality in Europe and Asia. This paper provides an outline of public health research and history as it relates to naturally occurring inorganic mineral dusts. We summarize results of current public health research and describe some of the many challenges related to understanding health effects from exposures to dust aerosols.

  5. Towards a framework for testing general relativity with extreme-mass-ratio-inspiral observations

    NASA Astrophysics Data System (ADS)

    Chua, A. J. K.; Hee, S.; Handley, W. J.; Higson, E.; Moore, C. J.; Gair, J. R.; Hobson, M. P.; Lasenby, A. N.

    2018-04-01

    Extreme-mass-ratio-inspiral observations from future space-based gravitational-wave detectors such as LISA will enable strong-field tests of general relativity with unprecedented precision, but at prohibitive computational cost if existing statistical techniques are used. In one such test that is currently employed for LIGO black-hole binary mergers, generic deviations from relativity are represented by N deformation parameters in a generalised waveform model; the Bayesian evidence for each of its 2N combinatorial submodels is then combined into a posterior odds ratio for modified gravity over relativity in a null-hypothesis test. We adapt and apply this test to a generalised model for extreme-mass-ratio inspirals constructed on deformed black-hole spacetimes, and focus our investigation on how computational efficiency can be increased through an evidence-free method of model selection. This method is akin to the algorithm known as product-space Markov chain Monte Carlo, but uses nested sampling and improved error estimates from a rethreading technique. We perform benchmarking and robustness checks for the method, and find order-of-magnitude computational gains over regular nested sampling in the case of synthetic data generated from the null model.

  6. 46 CFR 52.01-100 - Openings and compensation (modifies PG-32 through PG-39, PG-42 through PG-55).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Openings and compensation (modifies PG-32 through PG-39, PG-42 through PG-55). 52.01-100 Section 52.01-100 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-100 Openings and compensation (modifies PG-32 through PG-39, PG-42...

  7. 46 CFR 52.01-95 - Design (modifies PG-16 through PG-31 and PG-100).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Design (modifies PG-16 through PG-31 and PG-100). 52.01-95 Section 52.01-95 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-95 Design (modifies PG-16 through PG-31 and PG-100). (a) Requirements. Boilers required to be designe...

  8. 46 CFR 52.01-100 - Openings and compensation (modifies PG-32 through PG-39, PG-42 through PG-55).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Openings and compensation (modifies PG-32 through PG-39, PG-42 through PG-55). 52.01-100 Section 52.01-100 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-100 Openings and compensation (modifies PG-32 through PG-39, PG-42...

  9. 46 CFR 52.01-100 - Openings and compensation (modifies PG-32 through PG-39, PG-42 through PG-55).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Openings and compensation (modifies PG-32 through PG-39, PG-42 through PG-55). 52.01-100 Section 52.01-100 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-100 Openings and compensation (modifies PG-32 through PG-39, PG-42...

  10. 46 CFR 52.01-120 - Safety valves and safety relief valves (modifies PG-67 through PG-73).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Safety valves and safety relief valves (modifies PG-67 through PG-73). 52.01-120 Section 52.01-120 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-120 Safety valves and safety relief valves (modifies PG-67 through PG-73). (a)...

  11. 46 CFR 52.01-120 - Safety valves and safety relief valves (modifies PG-67 through PG-73).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Safety valves and safety relief valves (modifies PG-67 through PG-73). 52.01-120 Section 52.01-120 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-120 Safety valves and safety relief valves (modifies PG-67 through PG-73). (a)...

  12. 46 CFR 52.01-100 - Openings and compensation (modifies PG-32 through PG-39, PG-42 through PG-55).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Openings and compensation (modifies PG-32 through PG-39, PG-42 through PG-55). 52.01-100 Section 52.01-100 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-100 Openings and compensation (modifies PG-32 through PG-39, PG-42...

  13. 46 CFR 52.01-120 - Safety valves and safety relief valves (modifies PG-67 through PG-73).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Safety valves and safety relief valves (modifies PG-67 through PG-73). 52.01-120 Section 52.01-120 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-120 Safety valves and safety relief valves (modifies PG-67 through PG-73). (a)...

  14. 46 CFR 52.01-120 - Safety valves and safety relief valves (modifies PG-67 through PG-73).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Safety valves and safety relief valves (modifies PG-67 through PG-73). 52.01-120 Section 52.01-120 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-120 Safety valves and safety relief valves (modifies PG-67 through PG-73). (a)...

  15. 46 CFR 52.01-100 - Openings and compensation (modifies PG-32 through PG-39, PG-42 through PG-55).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Openings and compensation (modifies PG-32 through PG-39, PG-42 through PG-55). 52.01-100 Section 52.01-100 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-100 Openings and compensation (modifies PG-32 through PG-39, PG-42...

  16. 46 CFR 52.01-95 - Design (modifies PG-16 through PG-31 and PG-100).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Design (modifies PG-16 through PG-31 and PG-100). 52.01-95 Section 52.01-95 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-95 Design (modifies PG-16 through PG-31 and PG-100). (a) Requirements. Boilers required to be designe...

  17. 46 CFR 52.01-120 - Safety valves and safety relief valves (modifies PG-67 through PG-73).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Safety valves and safety relief valves (modifies PG-67 through PG-73). 52.01-120 Section 52.01-120 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-120 Safety valves and safety relief valves (modifies PG-67 through PG-73). (a)...

  18. Middle Pliocene vegetation: Reconstructions, paleoclimatic inferences, and boundary conditions for climate modeling

    USGS Publications Warehouse

    Thompson, R.S.; Fleming, R.F.

    1996-01-01

    The general characteristics of global vegetation during the middle Pliocene warm period can be reconstructed from fossil pollen and plant megafossil data. The largest differences between Pliocene vegetation and that of today occurred at high latitudes in both hemispheres, where warming was pronounced relative to today. In the Northern Hemisphere coniferous forests lived in the modern tundra and polar desert regions, whereas in the Southern Hemisphere southern beech apparently grew in coastal areas of Antarctica. Pliocene middle latitude vegetation differed less, although moister-than-modern conditions supported forest and woodland growth in some regions now covered by steppe or grassland. Pliocene tropical vegetation reflects essentially modern conditions in some regions and slightly cooler-than-or warmer-than- modern climates in other areas. Changes in topography induced by tectonics may be responsible for many of the climatic changes since the Pliocene in both middle and lower latitudes. However, the overall latitudinal progression of climatic conditions on land parallels that seen in the reconstruction of middle Pliocene sea-surface temperatures. Pliocene paleovegetational data was employed to construct a 2????2?? global grid of estimated mid-Pliocene vegetational cover for use as boundary conditions for numerical General Circulation Model simulations of middle Pliocene climates. Continental outlines and topography were first modified to represent the Pliocene landscape on the 2????2?? grid. A modern 1????1?? vegetation grid was simplified and mapped on this Pliocene grid, and then modified following general geographic trends evident in the Pliocene paleovegetation data set.

  19. Face processing in adolescents with positive and negative threat bias.

    PubMed

    Sylvester, C M; Petersen, S E; Luby, J L; Barch, D M

    2017-04-01

    Individuals with anxiety disorders exhibit a 'vigilance-avoidance' pattern of attention to threatening stimuli when threatening and neutral stimuli are presented simultaneously, a phenomenon referred to as 'threat bias'. Modifying threat bias through cognitive retraining during adolescence reduces symptoms of anxiety, and so elucidating neural mechanisms of threat bias during adolescence is of high importance. We explored neural mechanisms by testing whether threat bias in adolescents is associated with generalized or threat-specific differences in the neural processing of faces. Subjects were categorized into those with (n = 25) and without (n = 27) threat avoidance based on a dot-probe task at average age 12.9 years. Threat avoidance in this cohort has previously been shown to index threat bias. Brain response to individually presented angry and neutral faces was assessed in a separate session using functional magnetic resonance imaging. Adolescents with threat avoidance exhibited lower activity for both angry and neutral faces relative to controls in several regions in the occipital, parietal, and temporal lobes involved in early visual and facial processing. Results generalized to happy, sad, and fearful faces. Adolescents with a prior history of depression and/or an anxiety disorder had lower activity for all faces in these same regions. A subset of results replicated in an independent dataset. Threat bias is associated with generalized, rather than threat-specific, differences in the neural processing of faces in adolescents. Findings may aid in the development of novel treatments for anxiety disorders that use attention training to modify threat bias.

  20. Astrophysical applications of the post-Tolman-Oppenheimer-Volkoff formalism

    NASA Astrophysics Data System (ADS)

    Glampedakis, Kostas; Pappas, George; Silva, Hector O.; Berti, Emanuele

    2016-08-01

    The bulk properties of spherically symmetric stars in general relativity can be obtained by integrating the Tolman-Oppenheimer-Volkoff (TOV) equations. In previous work [K. Glampedakis, G. Pappas, H. O. Silva, and E. Berti, Phys. Rev. D 92, 024056 (2015)], we developed a "post-TOV" formalism—inspired by parametrized post-Newtonian theory—which allows us to classify in a parametrized, phenomenological form all possible perturbative deviations from the structure of compact stars in general relativity that may be induced by modified gravity at second post-Newtonian order. In this paper we extend the formalism to deal with the stellar exterior, and we compute several potential astrophysical observables within the post-TOV formalism: the surface redshift zs, the apparent radius Rapp, the Eddington luminosity at infinity LE∞ and the orbital frequencies. We show that, at leading order, all of these quantities depend on just two post-TOV parameters μ1 and χ , and we discuss the possibility to measure (or set upper bounds on) these parameters.

  1. Male sexual strategies modify ratings of female models with specific waist-to-hip ratios.

    PubMed

    Brase, Gary L; Walker, Gary

    2004-06-01

    Female waist-to-hip ratio (WHR) has generally been an important general predictor of ratings of physical attractiveness and related characteristics. Individual differences in ratings do exist, however, and may be related to differences in the reproductive tactics of the male raters such as pursuit of short-term or long-term relationships and adjustments based on perceptions of one's own quality as a mate. Forty males, categorized according to sociosexual orientation and physical qualities (WHR, Body Mass Index, and self-rated desirability), rated female models on both attractiveness and likelihood they would approach them. Sociosexually restricted males were less likely to approach females rated as most attractive (with 0.68-0.72 WHR), as compared with unrestricted males. Males with lower scores in terms of physical qualities gave ratings indicating more favorable evaluations of female models with lower WHR. The results indicate that attractiveness and willingness to approach are overlapping but distinguishable constructs, both of which are influenced by variations in characteristics of the raters.

  2. Quality of life, job satisfaction and their related factors among nurses working in king Abdulaziz University Hospital, Jeddah, Saudi Arabia.

    PubMed

    Ibrahim, Nahla Khamis; Alzahrani, Nujood Abdulwahed; Batwie, Afnan Ateeg; Abushal, Razan Abdulaziz; Almogati, Ghazwa Ghazzay; Sattam, Munirah Abdulrahman; Hussin, Bodour Khalid

    2016-08-01

    To assess Quality of Life, job satisfaction and their related factors among nurses working in King Abdulaziz University Hospital, Jeddah, Saudi Arabia. A cross-sectional survey was conducted among 268 nurses, 2014/2015. A validated, confidential data collection sheet was utilized. It contained the World Health Organization Quality of Life-BREF (WHOQOL-BREF), and Job Descriptive Index/Job in General (JDI/JIG) scales. The majority of nurses (83.5%) perceived their general QOL as very good and good. Age, marital status, having children, nationality, income, education, residence, working experience, department and shift time were associated with QOL domains (p < 0.05). Similarly, working experience, income, shifts, working in inpatient and surgical departments were associated with job satisfaction. Positive correlations were found between job satisfaction and different QOL domains, and between different JDI/JIG subscales together. Improvement of the modifiable factors as nurses' income and shift time is needed for better QOL and job satisfaction.

  3. Reassessment of Resuspension Factor Following Radionuclide Dispersal: Toward a General-purpose Rate Constant

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Marshall, Shaun; Potter, Charles; Medich, David

    A recent analysis of historical radionuclide resuspension datasets con rmed the general applicability of the Anspaugh and modified Anspaugh models of resuspension factors following both controlled and disastrous releases. The observations appear to increase in variance earlier in time, however all points were equally weighted in statistical fit calculations, inducing a positive skewing of resuspension coeffcients. Such data are extracted from the available deposition experiments spanning 2900 days. Measurements within a 3-day window are grouped into singular sample sets to construct standard deviations. A refitting is performed using a relative instrumental weighting of the observations. The resulting best-fit equations producesmore » tamer exponentials which give decreased integrated resuspension factor values relative to those reported by Anspaugh. As expected, the fits attenuate greater error amongst the data at earlier time. The reevaluation provides a sharper contrast between the empirical models, and reafirms their deficiencies in the short-lived timeframe wherein the dynamics of particulate dispersion dominate the resuspension process.« less

  4. Gravitational-Wave Tests of General Relativity with Ground-Based Detectors and Pulsar-Timing Arrays.

    PubMed

    Yunes, Nicolás; Siemens, Xavier

    2013-01-01

    This review is focused on tests of Einstein's theory of general relativity with gravitational waves that are detectable by ground-based interferometers and pulsar-timing experiments. Einstein's theory has been greatly constrained in the quasi-linear, quasi-stationary regime, where gravity is weak and velocities are small. Gravitational waves will allow us to probe a complimentary, yet previously unexplored regime: the non-linear and dynamical strong-field regime . Such a regime is, for example, applicable to compact binaries coalescing, where characteristic velocities can reach fifty percent the speed of light and gravitational fields are large and dynamical. This review begins with the theoretical basis and the predicted gravitational-wave observables of modified gravity theories. The review continues with a brief description of the detectors, including both gravitational-wave interferometers and pulsar-timing arrays, leading to a discussion of the data analysis formalism that is applicable for such tests. The review ends with a discussion of gravitational-wave tests for compact binary systems.

  5. User's manual for CNVUFAC, the general dynamics heat-transfer radiation view factor program

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wong, R. L.

    CNVUFAC, the General Dynamics heat-transfer radiation veiw factor program, has been adapted for use on the LLL CDC 7600 computer system. The input and output have been modified, and a node incrementing logic was included to make the code compatible with the TRUMP thermal analyzer and related codes. The program performs the multiple integration necessary to evaluate the geometric black-body radiaton node to node view factors. Card image output that contains node number and view factor information is generated for input into the related program GRAY. Program GRAY is then used to include the effects of gray-body emissivities and multiplemore » reflections, generating the effective gray-body view factors usable in TRUMP. CNVUFAC uses an elemental area summation scheme to evaluate the multiple integrals. The program permits shadowing and self-shadowing. The basic configuration shapes that can be considered are cylinders, cones, spheres, ellipsoids, flat plates, disks, toroids, and polynomials of revolution. Portions of these shapes can also be considered.« less

  6. Robust Adaptive Modified Newton Algorithm for Generalized Eigendecomposition and Its Application

    NASA Astrophysics Data System (ADS)

    Yang, Jian; Yang, Feng; Xi, Hong-Sheng; Guo, Wei; Sheng, Yanmin

    2007-12-01

    We propose a robust adaptive algorithm for generalized eigendecomposition problems that arise in modern signal processing applications. To that extent, the generalized eigendecomposition problem is reinterpreted as an unconstrained nonlinear optimization problem. Starting from the proposed cost function and making use of an approximation of the Hessian matrix, a robust modified Newton algorithm is derived. A rigorous analysis of its convergence properties is presented by using stochastic approximation theory. We also apply this theory to solve the signal reception problem of multicarrier DS-CDMA to illustrate its practical application. The simulation results show that the proposed algorithm has fast convergence and excellent tracking capability, which are important in a practical time-varying communication environment.

  7. Evaluation of certain food additives.

    PubMed

    2015-01-01

    This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives, including flavouring agents, and to prepare specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of and assessment of dietary exposure to food additives, including flavouring agents. A summary follows of the Committee's evaluations of technical, toxicological and dietary exposure data for eight food additives (Benzoe tonkinensis; carrageenan; citric and fatty acid esters of glycerol; gardenia yellow; lutein esters from Tagetes erecta; octenyl succinic acid-modified gum arabic; octenyl succinic acid-modified starch; paprika extract; and pectin) and eight groups of flavouring agents (aliphatic and alicyclic hydrocarbons; aliphatic and aromatic ethers; ionones and structurally related substances; miscellaneous nitrogen-containing substances; monocyclic and bicyclic secondary alcohols, ketones and related esters; phenol and phenol derivatives; phenyl-substituted aliphatic alcohols and related aldehydes and esters; and sulfur-containing heterocyclic compounds). Specifications for the following food additives were revised: citric acid; gellan gum; polyoxyethylene (20) sorbitan monostearate; potassium aluminium silicate; and Quillaia extract (Type 2). Annexed to the report are tables summarizing the Committee's recommendations for dietary exposures to and toxicological evaluations of all of the food additives and flavouring agents considered at this meeting.

  8. Latex modified Portland cement overlays : an analysis of samples removed from a bridge deck.

    DOT National Transportation Integrated Search

    1975-01-01

    This report describes an evaluation of the latex modified mortar overlay the Route 85 (NBL) bridge over the Roanoke River. While the performance of the overlay has been generally satisfactory, corings and chloride analyses indicate the possibility of...

  9. Contemporary Research on Parenting: Conceptual, Methodological, and Translational Issues

    PubMed Central

    Sleddens, Ester F. C.; Berge, Jerica; Connell, Lauren; Govig, Bert; Hennessy, Erin; Liggett, Leanne; Mallan, Kimberley; Santa Maria, Diane; Odoms-Young, Angela; St. George, Sara M.

    2013-01-01

    Abstract Researchers over the last decade have documented the association between general parenting style and numerous factors related to childhood obesity (e.g., children's eating behaviors, physical activity, and weight status). Many recent childhood obesity prevention programs are family focused and designed to modify parenting behaviors thought to contribute to childhood obesity risk. This article presents a brief consideration of conceptual, methodological, and translational issues that can inform future research on the role of parenting in childhood obesity. They include: (1) General versus domain specific parenting styles and practices; (2) the role of ethnicity and culture; (3) assessing bidirectional influences; (4) broadening assessments beyond the immediate family; (5) novel approaches to parenting measurement; and (6) designing effective interventions. Numerous directions for future research are offered. PMID:23944927

  10. Space Trajectories Error Analysis (STEAP) Programs. Volume 1: Analytic manual, update

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Manual revisions are presented for the modified and expanded STEAP series. The STEAP 2 is composed of three independent but related programs: NOMAL for the generation of n-body nominal trajectories performing a number of deterministic guidance events; ERRAN for the linear error analysis and generalized covariance analysis along specific targeted trajectories; and SIMUL for testing the mathematical models used in the navigation and guidance process. The analytic manual provides general problem description, formulation, and solution and the detailed analysis of subroutines. The programmers' manual gives descriptions of the overall structure of the programs as well as the computational flow and analysis of the individual subroutines. The user's manual provides information on the input and output quantities of the programs. These are updates to N69-36472 and N69-36473.

  11. Spacelab Life Sciences 1, development towards successive life sciences flights

    NASA Technical Reports Server (NTRS)

    Dalton, B. P.; Jahns, G.; Hogan, R.

    1992-01-01

    A general review is presented of flight data and related hardware developments for Spacelab Life Sciences (SLS) 1 with an eye toward applying this knowledge to projected flight planning. Specific attention is given to the Research Animal Holding Facility (RAHF), the General Purpose Work Station (GPWS), the Small Mass Measuring Instrument (SMMI), and the Animal Enclosure Module (AEM). Preflight and in-flight testing methods are detailed including biocompatibility tests, parametric engineering sensitivity analyses, measurements of environmental parameters, and studies of operational interfaces. Particulate containment is demonstrated for some of the equipment, and successful use of the GPWS, RAHF, AEM, and SMMI are reported. The in-flight data are useful for developing more advanced hardware such as the AEM for SLS flight 2 and the modified RAHF for SLS flight 3.

  12. Characteristics of sediment transport at selected sites along the Missouri River, 2011–12

    USGS Publications Warehouse

    Rus, David L.; Galloway, Joel M.; Alexander, Jason S.

    2015-10-22

    The Modified-Einstein Procedure tended to predict greater total-sediment loads when compared to measured values. These differences may be the result of sediment deficits in the Missouri River that lead to an overprediction by the Modified-Einstein Procedure, the unsampled zone above the streambed that leads to an underprediction by the suspended sampler, or general uncertainty in the sampling approach. The differences between total-sediment load obtained through measurements and that estimated from applied theoretical procedures such as the Modified-Einstein Procedure pose a challenge for reliably characterizing total-sediment transport. Though it is not clear which of the two techniques is more accurate, the general tendency of the two to be within an order of magnitude of one another may be adequate for many sediment studies.

  13. Atheroprotective immunization with malondialdehyde-modified LDL is hapten specific and dependent on advanced MDA adducts: implications for development of an atheroprotective vaccine1[S

    PubMed Central

    Gonen, Ayelet; Hansen, Lotte F.; Turner, William W.; Montano, Erica N.; Que, Xuchu; Rafia, Apaїs; Chou, Meng-Yun; Wiesner, Philipp; Tsiantoulas, Dimitrios; Corr, Maripat; VanNieuwenhze, Michael S.; Tsimikas, Sotirios; Binder, Christoph J.; Witztum, Joseph L.; Hartvigsen, Karsten

    2014-01-01

    Immunization with homologous malondialdehyde (MDA)-modified LDL (MDA-LDL) leads to atheroprotection in experimental models supporting the concept that a vaccine to oxidation-specific epitopes (OSEs) of oxidized LDL could limit atherogenesis. However, modification of human LDL with OSE to use as an immunogen would be impractical for generalized use. Furthermore, when MDA is used to modify LDL, a wide variety of related MDA adducts are formed, both simple and more complex. To define the relevant epitopes that would reproduce the atheroprotective effects of immunization with MDA-LDL, we sought to determine the responsible immunodominant and atheroprotective adducts. We now demonstrate that fluorescent adducts of MDA involving the condensation of two or more MDA molecules with lysine to form malondialdehyde-acetaldehyde (MAA)-type adducts generate immunodominant epitopes that lead to atheroprotective responses. We further demonstrate that a T helper (Th) 2-biased hapten-specific humoral and cellular response is sufficient, and thus, MAA-modified homologous albumin is an equally effective immunogen. We further show that such Th2-biased humoral responses per se are not atheroprotective if they do not target relevant antigens. These data demonstrate the feasibility of development of a small-molecule immunogen that could stimulate MAA-specific immune responses, which could be used to develop a vaccine approach to retard or prevent atherogenesis. PMID:25143462

  14. The Validity of the Modified Sit-and-Reach Test in College-Age Students.

    ERIC Educational Resources Information Center

    Minkler, Sharin; Patterson, Patricia

    1994-01-01

    Reports a study that examined the criterion-related validity of the modified sit-and-reach test against criterion measures of hamstring and low back flexibility in college students. Results indicated the modified sit-and-reach test moderately related to hamstring flexibility, but its relation to low back flexibility was low. (SM)

  15. Geometric Lagrangian approach to the physical degree of freedom count in field theory

    NASA Astrophysics Data System (ADS)

    Díaz, Bogar; Montesinos, Merced

    2018-05-01

    To circumvent some technical difficulties faced by the geometric Lagrangian approach to the physical degree of freedom count presented in the work of Díaz, Higuita, and Montesinos [J. Math. Phys. 55, 122901 (2014)] that prevent its direct implementation to field theory, in this paper, we slightly modify the geometric Lagrangian approach in such a way that its resulting version works perfectly for field theory (and for particle systems, of course). As in previous work, the current approach also allows us to directly get the Lagrangian constraints, a new Lagrangian formula for the counting of the number of physical degrees of freedom, the gauge transformations, and the number of first- and second-class constraints for any action principle based on a Lagrangian depending on the fields and their first derivatives without performing any Dirac's canonical analysis. An advantage of this approach over the previous work is that it also allows us to handle the reducibility of the constraints and to get the off-shell gauge transformations. The theoretical framework is illustrated in 3-dimensional generalized general relativity (Palatini and Witten's exotic actions), Chern-Simons theory, 4-dimensional BF theory, and 4-dimensional general relativity given by Palatini's action with a cosmological constant.

  16. Empirical Investigation of a Model of Sexual Minority Specific and General Risk Factors for Intimate Partner Violence among Lesbian Women

    PubMed Central

    Lewis, Robin J.; Mason, Tyler B.; Winstead, Barbara A.; Kelley, Michelle L.

    2015-01-01

    Objective This study proposed and tested the first conceptual model of sexual minority specific (discrimination, internalized homophobia) and more general risk factors (perpetrator and partner alcohol use, anger, relationship satisfaction) for intimate partner violence among partnered lesbian women. Method Self-identified lesbian women (N=1048) were recruited from online market research panels. Participants completed an online survey that included measures of minority stress, anger, alcohol use and alcohol-related problems, relationship satisfaction, psychological aggression, and physical violence. Results The model demonstrated good fit and significant links from sexual minority discrimination to internalized homophobia and anger, from internalized homophobia to anger and alcohol problems, and from alcohol problems to intimate partner violence. Partner alcohol use predicted partner physical violence. Relationship dissatisfaction was associated with physical violence via psychological aggression. Physical violence was bidirectional. Conclusions Minority stress, anger, alcohol use and alcohol-related problems play an important role in perpetration of psychological aggression and physical violence in lesbian women's intimate partner relationships. The results of this study provide evidence of potentially modifiable sexual minority specific and more general risk factors for lesbian women's partner violence. PMID:28239508

  17. Modifiable Midlife Risk Factors for Late-Life Cognitive Impairment and Dementia

    PubMed Central

    Hughes, Tiffany F.; Ganguli, Mary

    2009-01-01

    The baby boom generation is approaching the age of greatest risk for cognitive impairment and dementia. There is growing interest in strategies to modify the environment in midlife to increase the probability of maintaining cognitive health in late life. Several potentially modifiable risk factors have been studied in relation to cognitive impairment and dementia in late life, but methodological limitations of observational research have resulted in some inconsistencies across studies. The most promising strategies are maintaining cardiovascular health, engagement in mental, physical, and social activities, using alcohol in moderation, abstaining from tobacco use, and following a heart-healthy diet. Other factors that may influence cognitive health are occupational attainment, depression, personality, exposure to general anesthesia, head injury, postmenopausal hormone therapy, non-steroidal anti-inflammatory medications, and nutritional supplements such as antioxidants. Some long-term observational studies initiated in midlife or earlier, and some randomized controlled trials, have examined the effects of specific cognitive health promotion behaviors in midlife on the risk of cognitive impairment in late life. Overall, these studies provide limited support for risk reduction at this time. Recommendations and challenges for developing effective strategies to reduce the burden of cognitive impairment and dementia in the future are discussed. PMID:19946443

  18. High-performance computational fluid dynamics: a custom-code approach

    NASA Astrophysics Data System (ADS)

    Fannon, James; Loiseau, Jean-Christophe; Valluri, Prashant; Bethune, Iain; Náraigh, Lennon Ó.

    2016-07-01

    We introduce a modified and simplified version of the pre-existing fully parallelized three-dimensional Navier-Stokes flow solver known as TPLS. We demonstrate how the simplified version can be used as a pedagogical tool for the study of computational fluid dynamics (CFDs) and parallel computing. TPLS is at its heart a two-phase flow solver, and uses calls to a range of external libraries to accelerate its performance. However, in the present context we narrow the focus of the study to basic hydrodynamics and parallel computing techniques, and the code is therefore simplified and modified to simulate pressure-driven single-phase flow in a channel, using only relatively simple Fortran 90 code with MPI parallelization, but no calls to any other external libraries. The modified code is analysed in order to both validate its accuracy and investigate its scalability up to 1000 CPU cores. Simulations are performed for several benchmark cases in pressure-driven channel flow, including a turbulent simulation, wherein the turbulence is incorporated via the large-eddy simulation technique. The work may be of use to advanced undergraduate and graduate students as an introductory study in CFDs, while also providing insight for those interested in more general aspects of high-performance computing.

  19. Unscreening Modified Gravity in the Matter Power Spectrum.

    PubMed

    Lombriser, Lucas; Simpson, Fergus; Mead, Alexander

    2015-06-26

    Viable modifications of gravity that may produce cosmic acceleration need to be screened in high-density regions such as the Solar System, where general relativity is well tested. Screening mechanisms also prevent strong anomalies in the large-scale structure and limit the constraints that can be inferred on these gravity models from cosmology. We find that by suppressing the contribution of the screened high-density regions in the matter power spectrum, allowing a greater contribution of unscreened low densities, modified gravity models can be more readily discriminated from the concordance cosmology. Moreover, by variation of density thresholds, degeneracies with other effects may be dealt with more adequately. Specializing to chameleon gravity as a worked example for screening in modified gravity, employing N-body simulations of f(R) models and the halo model of chameleon theories, we demonstrate the effectiveness of this method. We find that a percent-level measurement of the clipped power at k<0.3h/Mpc can yield constraints on chameleon models that are more stringent than what is inferred from Solar System tests or distance indicators in unscreened dwarf galaxies. Finally, we verify that our method is also applicable to the Vainshtein mechanism.

  20. Comparison of modified atmosphere packaging and vacuum packaging for long period storage of dry-cured ham: effects on colour, texture and microbiological quality.

    PubMed

    García-Esteban, Marta; Ansorena, Diana; Astiasarán, Iciar

    2004-05-01

    Slices of dry-cured hams (Biceps femoris muscle) were stored during 8 weeks under vacuum and modified atmospheres (100% N(2) and a mixture of 20% CO(2) and 80% N(2)) in order to study the modifications on colour, texture and microbial counts during that period. Lightness was found to be more stable when samples were stored with 20% CO(2) and 80% N(2) without statistical differences between vacuum and 100% N(2). A slight whiteness was observed in the vacuum packed samples. Yellowness increased during time in vacuum packed samples, although no differences were found among the three conditions at the end of the study. Redness values were not affected by time or by the packaging system. With regard to texture, values found for all samples were within the normal range for this type of products, although it was observed that modified atmosphere packaging preserved samples better from hardening than vacuum packaging. No safety problems were detected in relation to the microbial quality in any case. In general, no clear differences were found among the three packaging systems for colour, texture and microbial quality in the storage conditions studied.

  1. Genetically Modified Food: Knowledge and Attitude of Teachers and Students

    NASA Astrophysics Data System (ADS)

    Mohapatra, Animesh K.; Priyadarshini, Deepika; Biswas, Antara

    2010-10-01

    The concepts behind the technology of genetic modification of organisms and its applications are complex. A diverse range of opinions, public concern and considerable media interest accompanies the subject. This study explores the knowledge and attitudes of science teachers and senior secondary biology students about the application of a rapidly expanding technology, genetic engineering, to food production. The results indicated significant difference in understanding of concepts related with genetically engineered food stuffs between teachers and students. The most common ideas about genetically modified food were that cross bred plants and genetically modified plants are not same, GM organisms are produced by inserting a foreign gene into a plant or animal and are high yielding. More teachers thought that genetically engineered food stuffs were unsafe for the environment. Both teachers and students showed number of misconceptions, for example, the pesticidal proteins produced by GM organisms have indirect effects through bioaccumulation, induces production of allergic proteins, genetic engineering is production of new genes, GM plants are leaky sieves and that transgenes are more likely to introgress into wild species than mutated species. In general, more students saw benefits while teachers were cautious about the advantages of genetically engineered food stuffs.

  2. Pancreatic ductal adenocarcinoma: Risk factors, screening, and early detection

    PubMed Central

    Becker, Andrew E; Hernandez, Yasmin G; Frucht, Harold; Lucas, Aimee L

    2014-01-01

    Pancreatic cancer is the fourth most common cause of cancer-related deaths in the United States, with over 38000 deaths in 2013. The opportunity to detect pancreatic cancer while it is still curable is dependent on our ability to identify and screen high-risk populations before their symptoms arise. Risk factors for developing pancreatic cancer include multiple genetic syndromes as well as modifiable risk factors. Genetic conditions include hereditary breast and ovarian cancer syndrome, Lynch Syndrome, familial adenomatous polyposis, Peutz-Jeghers Syndrome, familial atypical multiple mole melanoma syndrome, hereditary pancreatitis, cystic fibrosis, and ataxia-telangiectasia; having a genetic predisposition can raise the risk of developing pancreatic cancer up to 132-fold over the general population. Modifiable risk factors, which include tobacco exposure, alcohol use, chronic pancreatitis, diet, obesity, diabetes mellitus, as well as certain abdominal surgeries and infections, have also been shown to increase the risk of pancreatic cancer development. Several large-volume centers have initiated such screening protocols, and consensus-based guidelines for screening high-risk groups have recently been published. The focus of this review will be both the genetic and modifiable risk factors implicated in pancreatic cancer, as well as a review of screening strategies and their diagnostic yields. PMID:25170203

  3. A comparison of the stability of beverage cloud emulsions formulated with different gum acacia- and starch-based emulsifiers.

    PubMed

    Reiner, S J; Reineccius, G A; Peppard, T L

    2010-06-01

    The performance of several hydrocolloids (3 gum acacias, 1 modified gum acacia, and 3 modified starches) in stabilizing beverage emulsions and corresponding model beverages was investigated employing different core materials, emulsifier usage levels, and storage temperatures. Concentrated emulsions were prepared using orange terpenes or Miglyol 812 (comprising medium-chain triglycerides, MCT) weighted 1:1 with ester gum, stored at 25 or 35 degrees C, and analyzed on days 0, 1, and 3. On day 3, model beverages were made from each emulsion, stored at both temperatures, and analyzed weekly for 4 wk. Stability of concentrated emulsions was assessed by measuring mean particle size and by visual observations of ringing; beverage stability was judged similarly and also by loss of turbidity. Particle size measurements showed concentrated emulsions containing gum acacia or modified gum acacia with either core material were stable over 3 d storage at both temperatures whereas those made with modified starches were not, destabilization being faster at 35 degrees C. Beverages based on orange terpenes, in contrast to Miglyol, yielded smaller mean particle sizes, both on manufacture and during storage, regardless of hydrocolloid used. Visual observations of ringing generally supported this finding. Modified gum acacia was evaluated at both recommended and higher usage levels, stability increasing in the latter case. In general, all gum acacia and modified gum acacia emulsifiers were superior in stability to those based on modified starches, at either temperature, for orange terpene-based beverages. In Miglyol-based beverages, similar results were seen, except 1 modified starch performed as well as the gum acacia products.

  4. Dispersive solitary wave solutions of Kadomtsev-Petviashvili and modified Kadomtsev-Petviashvili dynamical equations in unmagnetized dust plasma

    NASA Astrophysics Data System (ADS)

    Seadawy, A. R.; El-Rashidy, K.

    2018-03-01

    The Kadomtsev-Petviashvili (KP) and modified KP equations are two of the most universal models in nonlinear wave theory, which arises as a reduction of system with quadratic nonlinearity which admit weakly dispersive waves. The generalized extended tanh method and the F-expansion method are used to derive exact solitary waves solutions of KP and modified KP equations. The region of solutions are displayed graphically.

  5. CUA Annual Meeting Abstracts addition.

    PubMed

    2012-08-01

    : Foley catheters are assumed to drain the bladder to completion. We have previously shown that dependent loops along the drainage tubing create air-locks, which obstruct antegrade urine flow and result in un-drained residual bladder urine. We hypothesized that drainage characteristics of Foley catheters remain poorly understood by urologists and general surgeons. We conducted a nationwide survey of general surgery and urology training program faculty and residents, to assess perceptions of Foley catheter drainage. We designed a novel catheter drainage tube/bag that eliminates air-locks. : An anonymous illustrated questionnaire assessing Foley catheter use patterns and perception was sent to general surgery and urology residency programs (N=108) nationwide. A modified catheter drainage tube/bag unit was designed and tested. An ex vivo catheterized bladder model was designed to measure and compare urine drainage rates with the standard drainage system, versus with our novel design. : A total of 307 responses were collected from residents (55%) and faculty (45%); responses were similar among both groups (p<0.05). The majority reported that at their centers Foley catheter drainage tubes are generally positioned with a dependent loop (94.1%), and, that positioning with a dependent loop, versus without (78.1%) promoted optimal drainage. Antegrade drainage does not occur with a traditional drainage system when a >5.5 inch dependent loop in place. With our proposed design, which eliminates dependent loops, the bladder model emptied to completion consistently. : Traditional Foley catheter drainage systems, as commonly used, evacuate the bladder sub- optimally. More reliable and complete bladder drainage may decrease the incidence of catheter related UTI. The novel modified Foley catheter drainage tube/bag design presented here eliminates dependent loops, to optimize antegrade drainage.

  6. Numerical artifacts in the Generalized Porous Medium Equation: Why harmonic averaging itself is not to blame

    NASA Astrophysics Data System (ADS)

    Maddix, Danielle C.; Sampaio, Luiz; Gerritsen, Margot

    2018-05-01

    The degenerate parabolic Generalized Porous Medium Equation (GPME) poses numerical challenges due to self-sharpening and its sharp corner solutions. For these problems, we show results for two subclasses of the GPME with differentiable k (p) with respect to p, namely the Porous Medium Equation (PME) and the superslow diffusion equation. Spurious temporal oscillations, and nonphysical locking and lagging have been reported in the literature. These issues have been attributed to harmonic averaging of the coefficient k (p) for small p, and arithmetic averaging has been suggested as an alternative. We show that harmonic averaging is not solely responsible and that an improved discretization can mitigate these issues. Here, we investigate the causes of these numerical artifacts using modified equation analysis. The modified equation framework can be used for any type of discretization. We show results for the second order finite volume method. The observed problems with harmonic averaging can be traced to two leading error terms in its modified equation. This is also illustrated numerically through a Modified Harmonic Method (MHM) that can locally modify the critical terms to remove the aforementioned numerical artifacts.

  7. The "New Oxford English Dictionary" Project.

    ERIC Educational Resources Information Center

    Fawcett, Heather

    1993-01-01

    Describes the conversion of the 22,000-page Oxford English Dictionary to an electronic version incorporating a modified Standard Generalized Markup Language (SGML) syntax. Explains that the database designers chose structured markup because it supports users' data searching needs, allows textual components to be extracted or modified, and allows…

  8. Receptor Activity-modifying Protein-directed G Protein Signaling Specificity for the Calcitonin Gene-related Peptide Family of Receptors.

    PubMed

    Weston, Cathryn; Winfield, Ian; Harris, Matthew; Hodgson, Rose; Shah, Archna; Dowell, Simon J; Mobarec, Juan Carlos; Woodlock, David A; Reynolds, Christopher A; Poyner, David R; Watkins, Harriet A; Ladds, Graham

    2016-10-14

    The calcitonin gene-related peptide (CGRP) family of G protein-coupled receptors (GPCRs) is formed through the association of the calcitonin receptor-like receptor (CLR) and one of three receptor activity-modifying proteins (RAMPs). Binding of one of the three peptide ligands, CGRP, adrenomedullin (AM), and intermedin/adrenomedullin 2 (AM2), is well known to result in a Gα s -mediated increase in cAMP. Here we used modified yeast strains that couple receptor activation to cell growth, via chimeric yeast/Gα subunits, and HEK-293 cells to characterize the effect of different RAMP and ligand combinations on this pathway. We not only demonstrate functional couplings to both Gα s and Gα q but also identify a Gα i component to CLR signaling in both yeast and HEK-293 cells, which is absent in HEK-293S cells. We show that the CGRP family of receptors displays both ligand- and RAMP-dependent signaling bias among the Gα s , Gα i , and Gα q/11 pathways. The results are discussed in the context of RAMP interactions probed through molecular modeling and molecular dynamics simulations of the RAMP-GPCR-G protein complexes. This study further highlights the importance of RAMPs to CLR pharmacology and to bias in general, as well as identifying the importance of choosing an appropriate model system for the study of GPCR pharmacology. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Tinker-OpenMM: Absolute and relative alchemical free energies using AMOEBA on GPUs.

    PubMed

    Harger, Matthew; Li, Daniel; Wang, Zhi; Dalby, Kevin; Lagardère, Louis; Piquemal, Jean-Philip; Ponder, Jay; Ren, Pengyu

    2017-09-05

    The capabilities of the polarizable force fields for alchemical free energy calculations have been limited by the high computational cost and complexity of the underlying potential energy functions. In this work, we present a GPU-based general alchemical free energy simulation platform for polarizable potential AMOEBA. Tinker-OpenMM, the OpenMM implementation of the AMOEBA simulation engine has been modified to enable both absolute and relative alchemical simulations on GPUs, which leads to a ∼200-fold improvement in simulation speed over a single CPU core. We show that free energy values calculated using this platform agree with the results of Tinker simulations for the hydration of organic compounds and binding of host-guest systems within the statistical errors. In addition to absolute binding, we designed a relative alchemical approach for computing relative binding affinities of ligands to the same host, where a special path was applied to avoid numerical instability due to polarization between the different ligands that bind to the same site. This scheme is general and does not require ligands to have similar scaffolds. We show that relative hydration and binding free energy calculated using this approach match those computed from the absolute free energy approach. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  10. 28 CFR 35.136 - Service animals.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Service animals. 35.136 Section 35.136... LOCAL GOVERNMENT SERVICES General Requirements § 35.136 Service animals. (a) General. Generally, a public entity shall modify its policies, practices, or procedures to permit the use of a service animal...

  11. 28 CFR 35.136 - Service animals.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Service animals. 35.136 Section 35.136... LOCAL GOVERNMENT SERVICES General Requirements § 35.136 Service animals. (a) General. Generally, a public entity shall modify its policies, practices, or procedures to permit the use of a service animal...

  12. 28 CFR 35.136 - Service animals.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Service animals. 35.136 Section 35.136... LOCAL GOVERNMENT SERVICES General Requirements § 35.136 Service animals. (a) General. Generally, a public entity shall modify its policies, practices, or procedures to permit the use of a service animal...

  13. 28 CFR 35.136 - Service animals.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Service animals. 35.136 Section 35.136... LOCAL GOVERNMENT SERVICES General Requirements § 35.136 Service animals. (a) General. Generally, a public entity shall modify its policies, practices, or procedures to permit the use of a service animal...

  14. Finding Horndeski theories with Einstein gravity limits

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McManus, Ryan; Lombriser, Lucas; Peñarrubia, Jorge, E-mail: ryanm@roe.ac.uk, E-mail: llo@roe.ac.uk, E-mail: jorpega@roe.ac.uk

    The Horndeski action is the most general scalar-tensor theory with at most second-order derivatives in the equations of motion, thus evading Ostrogradsky instabilities and making it of interest when modifying gravity at large scales. To pass local tests of gravity, these modifications predominantly rely on nonlinear screening mechanisms that recover Einstein's Theory of General Relativity in regions of high density. We derive a set of conditions on the four free functions of the Horndeski action that examine whether a specific model embedded in the action possesses an Einstein gravity limit or not. For this purpose, we develop a new andmore » surprisingly simple scaling method that identifies dominant terms in the equations of motion by considering formal limits of the couplings that enter through the new terms in the modified action. This enables us to find regimes where nonlinear terms dominate and Einstein's field equations are recovered to leading order. Together with an efficient approximation of the scalar field profile, one can then further evaluate whether these limits can be attributed to a genuine screening effect. For illustration, we apply the analysis to both a cubic galileon and a chameleon model as well as to Brans-Dicke theory. Finally, we emphasise that the scaling method also provides a natural approach for performing post-Newtonian expansions in screened regimes.« less

  15. General and Direct Method for Preparing Oligonucleotide-Functionalized Metal-Organic Framework Nanoparticles.

    PubMed

    Wang, Shunzhi; McGuirk, C Michael; Ross, Michael B; Wang, Shuya; Chen, Pengcheng; Xing, Hang; Liu, Yuan; Mirkin, Chad A

    2017-07-26

    Metal-organic frameworks (MOFs) are a class of modular, crystalline, and porous materials that hold promise for storage and transport of chemical cargoes. Though MOFs have been studied in bulk forms, ways of deliberately manipulating the external surface functionality of MOF nanoparticles are less developed. A generalizable approach to modify their surfaces would allow one to impart chemical functionality onto the particle surface that is independent of the bulk MOF structure. Moreover, the use of a chemically programmable ligand, such as DNA, would allow for the manipulation of interparticle interactions. Herein, we report a coordination chemistry-based strategy for the surface functionalization of the external metal nodes of MOF nanoparticles with terminal phosphate-modified oligonucleotides. The external surfaces of nine distinct archetypical MOF particles containing four different metal species (Zr, Cr, Fe, and Al) were successfully functionalized with oligonucleotides, illustrating the generality of this strategy. By taking advantage of the programmable and specific interactions of DNA, 11 distinct MOF particle-inorganic particle core-satellite clusters were synthesized. In these hybrid nanoclusters, the relative stoichiometry, size, shape, and composition of the building blocks can all be independently controlled. This work provides access to a new set of nucleic acid-nanoparticle conjugates, which may be useful as programmable material building blocks and as probes for measuring and manipulating intracellular processes.

  16. Rational design of p53, an intrinsically unstructured protein, for the fabrication of novel molecular sensors.

    PubMed

    Geddie, Melissa L; O'Loughlin, Taryn L; Woods, Kristen K; Matsumura, Ichiro

    2005-10-21

    The dominant paradigm of protein engineering is structure-based site-directed mutagenesis. This rational approach is generally more effective for the engineering of local properties, such as substrate specificity, than global ones such as allostery. Previous workers have modified normally unregulated reporter enzymes, including beta-galactosidase, alkaline phosphatase, and beta-lactamase, so that the engineered versions are activated (up to 4-fold) by monoclonal antibodies. A reporter that could easily be "reprogrammed" for the facile detection of novel effectors (binding or modifying activities) would be useful in high throughput screens for directed evolution or drug discovery. Here we describe a straightforward and general solution to this potentially difficult design problem. The transcription factor p53 is normally regulated by a variety of post-translational modifications. The insertion of peptides into intrinsically unstructured domains of p53 generated variants that were activated up to 100-fold by novel effectors (proteases or antibodies). An engineered p53 was incorporated into an existing high throughput screen for the detection of human immunodeficiency virus protease, an arbitrarily chosen novel effector. These results suggest that the molecular recognition properties of intrinsically unstructured proteins are relatively easy to engineer and that the absence of crystal structures should not deter the rational engineering of this class of proteins.

  17. Preventing a Mass Disease: The Case of Gallstones Disease: Role and Competence for Family Physicians.

    PubMed

    Portincasa, Piero; Di Ciaula, Agostino; Grattagliano, Ignazio

    2016-07-01

    Gallstone formation is the result of a complex interaction between genetic and nongenetic factors. We searched and reviewed the available literature to define how the primary prevention of gallstones (cholesterol gallstones in particular) could be applied in general practice. Electronic bibliographical databases were searched. Prospective and retrospective cohort studies and case-controlled studies were analyzed and graded for evidence quality. The epidemiological data confirmed that genetic factors are estimated to account for only approximately 25% of the overall risk of gallstones, while metabolic/environmental factors are at least partially modifiable in stone-free risk groups, and are thus modifiable by primary prevention measures related to diet, lifestyle, and environmental factors (i.e., rapid weight loss, bariatric surgery, somatostatin or analogues therapy, transient gallbladder stasis, and hormone therapy). There is no specific recommendation for the secondary prevention of recurrent gallstones. Family physicians can contribute to preventing gallstones due to their capability to identify and effectively manage several risk factors discussed in this study. Although further studies are needed to better elucidate the involvement of epigenetic factors that may regulate the effect of environment and lifestyle on gene expression in the primary prevention of gallstone formation, preventive interventions are feasible and advisable in the general practice setting.

  18. Getting super-excited with modified dispersion relations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ashoorioon, Amjad; Casadio, Roberto; Geshnizjani, Ghazal

    We demonstrate that in some regions of parameter space, modified dispersion relations can lead to highly populated excited states, which we dub as 'super-excited' states. In order to prepare such super-excited states, we invoke dispersion relations that have negative slope in an interim sub-horizon phase at high momenta. This behaviour of quantum fluctuations can lead to large corrections relative to the Bunch-Davies power spectrum, which mimics highly excited initial conditions. We identify the Bogolyubov coefficients that can yield these power spectra. In the course of this computation, we also point out the shortcomings of the gluing method for evaluating themore » power spectrum and the Bogolyubov coefficients. As we discuss, there are other regions of parameter space, where the power spectrum does not get modified. Therefore, modified dispersion relations can also lead to so-called 'calm excited states'. We conclude by commenting on the possibility of obtaining these modified dispersion relations within the Effective Field Theory of Inflation.« less

  19. Mallampati test as a predictor of laryngoscopic view.

    PubMed

    Adamus, Milan; Fritscherova, Sarka; Hrabalek, Lumir; Gabrhelik, Tomas; Zapletalova, Jana; Janout, Vladimir

    2010-12-01

    To determine the accuracy of the modified Mallampati test for predicting difficult tracheal intubation. A cross-sectional, clinical, observational, non-blinded study. A quality analysis of anesthetic care. Operating theatres and department of anesthesiology in a university hospital. Following the local ethics committee approval and patients' informed consent to anesthesia, all adult patients (> 18 yrs) presenting for any type of non-emergency surgical procedures under general anesthesia requiring endotracheal intubation were enrolled. Prior to anesthesia, Samsoon and Young's modification of the Mallampati test (modified Mallampati test) was performed. Following induction, the anesthesiologist described the laryngoscopic view using the Cormack-Lehane scale. Classes 3 or 4 of the modified Mallampati test were considered a predictor of difficult intubation. Grades 3 or 4 of the Cormack-Lehane classification of the laryngoscopic view were defined as impaired glottic exposure. The sensitivity, specificity, positive and negative predictive value, relative risk, likelihood ratio and accuracy of the modified Mallampati test were calculated on 2x2 contingency tables. Of the total 1,518 patients enrolled, 48 had difficult intubation (3.2%). We failed to detect as many as 35.4% patients in whom glottis exposure during direct laryngoscopy was inadequate (sensitivity 0.646). Compared to the original article by Mallampati, we found lower specificity (0.824 vs. 0.995), lower positive predictive value (0.107 vs. 0.933), higher negative predictive value (0.986 vs. 0.928), lower likelihood ratio (3.68 vs. 91.0) and accuracy (0.819 vs. 0.929). When used as a single examination, the modified Mallampati test is of limited value in predicting difficult intubation.

  20. 49 CFR 1155.28 - Appellate procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Applications for a Land-Use-Exemption Permit § 1155.28 Appellate procedures. General rule. Petitions to modify, amend, or revoke land-use-exemption permits shall be decided in accordance with the Board's normal... amendment. (b) The Board will approve or deny petitions to modify, amend, or revoke a land-use-exemption...

  1. Developing and Improving Modified Achievement Level Descriptors: Rationale, Procedures, and Tools

    ERIC Educational Resources Information Center

    Quenemoen, Rachel; Albus, Debra; Rogers, Chris; Lazarus, Sheryl

    2010-01-01

    Some states are developing alternate assessments based on modified achievement standards (AA-MAS) to measure the academic achievement of some students with disabilities (Albus, Lazarus, Thurlow, & Cormier, 2009; Lazarus, Thurlow, Christensen, & Cormier, 2007). These assessments measure the same content as the general assessment for a given…

  2. Engineered microorganisms capable of producing target compounds under anaerobic conditions

    DOEpatents

    Buelter, Thomas [Denver, CO; Meinhold, Peter [Denver, CO; Feldman, Reid M. Renny [San Francisco, CA; Hawkins, Andrew C [Parker, CO; Urano, Jun [Irvine, CA; Bastian, Sabine [Pasadena, CA; Arnold, Frances [La Canada, CA

    2012-01-17

    The present invention is generally provides recombinant microorganisms comprising engineered metabolic pathways capable of producing C3-C5 alcohols under aerobic and anaerobic conditions. The invention further provides ketol-acid reductoisomerase enzymes which have been mutated or modified to increase their NADH-dependent activity or to switch the cofactor preference from NADPH to NADH and are expressed in the modified microorganisms. In addition, the invention provides isobutyraldehyde dehydrogenase enzymes expressed in modified microorganisms. Also provided are methods of producing beneficial metabolites under aerobic and anaerobic conditions by contacting a suitable substrate with the modified microorganisms of the present invention.

  3. Optic neuritis following aseptic meningitis associated with modified measles: a case report.

    PubMed

    Nakajima, Nobuhito; Ueda, Masayuki; Yamazaki, Mineo; Takahashi, Toshiyuki; Katayama, Yasuo

    2013-01-01

    In this study, we report the case of a 35-year-old woman with modified measles complicated by aseptic meningitis and subsequent optic neuritis. Although her initial manifestations were only flu-like symptoms without any Koplik's spots or skin rashes, virological testing confirmed an acute measles infection. Subsequently, right optic neuritis appeared after aseptic meningitis and was completely resolved following steroid pulse therapy. In general, modified measles is believed to be associated with mild symptoms and few neurological complications; however, our present observations demonstrated that modified measles can cause rapid neurological complications.

  4. Evaluation of a modified team based learning method for teaching general embryology to 1st year medical graduate students.

    PubMed

    Shankar, Nachiket; Roopa, R

    2009-01-01

    To encourage student participation in the learning process, the authors introduced a modified team based learning (TBL) method to cover two general embryology topics in the 1st year MBBS curriculum. The aim of this study was to evaluate students' perception of this method vis-à-vis the lecture method of teaching. A questionnaire was used to survey and evaluate the perceptions of 1st year MBBS students at the Department of Anatomy at our medical college in India. A total of eight classes were allotted to cover General Embryology. Six of these classes were conducted using the traditional didactic lecture method. Two topics were covered using the modified TBL method. Five teams of students were constituted, and each team was given handouts which contained basic factual material, four clinical case histories, and previous university exam questions from the topic. On the day of the session, these were discussed in the presence of the faculty facilitator. Students evaluated these sessions through a questionnaire. A majority of students felt that the modified TBL sessions were better at fulfilling learning objectives (46 students, 85%), enabled better understanding (43 students, 79%), were more interesting (43 students, 81%), ensured greater student participation (51 students, 94%) and involved greater effort on the part of students (53 students, 98%), as compared to traditional teaching methods. Most of the students (43 students, 79%) opined that more such sessions should be organized in the future. Responses from students show that the modified TBL classes could be utilized judiciously along with the traditional didactic lectures for teaching embryology.

  5. New general pore size distribution model by classical thermodynamics application: Activated carbon

    USGS Publications Warehouse

    Lordgooei, M.; Rood, M.J.; Rostam-Abadi, M.

    2001-01-01

    A model is developed using classical thermodynamics to characterize pore size distributions (PSDs) of materials containing micropores and mesopores. The thermal equation of equilibrium adsorption (TEEA) is used to provide thermodynamic properties and relate the relative pore filling pressure of vapors to the characteristic pore energies of the adsorbent/adsorbate system for micropore sizes. Pore characteristic energies are calculated by averaging of interaction energies between adsorbate molecules and adsorbent pore walls as well as considering adsorbate-adsorbate interactions. A modified Kelvin equation is used to characterize mesopore sizes by considering variation of the adsorbate surface tension and by excluding the adsorbed film layer for the pore size. The modified-Kelvin equation provides similar pore filling pressures as predicted by density functional theory. Combination of these models provides a complete PSD of the adsorbent for the micropores and mesopores. The resulting PSD is compared with the PSDs from Jaroniec and Choma and Horvath and Kawazoe models as well as a first-order approximation model using Polanyi theory. The major importance of this model is its basis on classical thermodynamic properties, less simplifying assumptions in its derivation compared to other methods, and ease of use.

  6. Expression, Localization of SUMO-1, and Analyses of Potential SUMOylated Proteins in Bubalus bubalis Spermatozoa

    PubMed Central

    Brohi, Rahim Dad; Wang, Li; Hassine, Najla Ben; Cao, Jing; Talpur, Hira Sajjad; Wu, Di; Huang, Chun-Jie; Rehman, Zia-Ur; Bhattarai, Dinesh; Huo, Li-Jun

    2017-01-01

    Mature spermatozoa have highly condensed DNA that is essentially silent both transcriptionally and translationally. Therefore, post translational modifications are very important for regulating sperm motility, morphology, and for male fertility in general. Protein sumoylation was recently demonstrated in human and rodent spermatozoa, with potential consequences for sperm motility and DNA integrity. We examined the expression and localization of small ubiquitin-related modifier-1 (SUMO-1) in the sperm of water buffalo (Bubalus bubalis) using immunofluorescence analysis. We confirmed the expression of SUMO-1 in the acrosome. We further found that SUMO-1 was lost if the acrosome reaction was induced by calcium ionophore A23187. Proteins modified or conjugated by SUMO-1 in water buffalo sperm were pulled down and analyzed by mass spectrometry. Sixty proteins were identified, including proteins important for sperm morphology and motility, such as relaxin receptors and cytoskeletal proteins, including tubulin chains, actins, and dyneins. Forty-six proteins were predicted as potential sumoylation targets. The expression of SUMO-1 in the acrosome region of water buffalo sperm and the identification of potentially SUMOylated proteins important for sperm function implicates sumoylation as a crucial PTM related to sperm function. PMID:28659810

  7. DNA Analyses in Food Safety and Quality: Current Status and Expectations

    NASA Astrophysics Data System (ADS)

    Marchelli, Rosangela; Tedeschi, Tullia; Tonelli, Alessandro

    Food safety and quality are very important issues receiving a lot of attention in most countries by producers, consumers and regulatory and control authorities. In particular, DNA analysis in food is becoming popular not only in relation to genetically modified products (GMOs), in which DNA modification is the "clue" of the novelty, but also in other fields like microbiology and pathogen detection, which require long times for the cultivation and specially in cases in which the microorganisms are not cultivable like some viruses, as well as for authenticity and allergen detection. A new topic concerning "nutrigenetics and nutrigenomics" has also been mentioned, very important but still in its infancy, which could lead in the future to a personalized diet. In this chapter we have described the main areas of food research and fields of application where DNA analysis is being performed and the relative methods of detection, which are generally based on PCR. The possibility/opportunity to detect DNA without previous amplification (PCR-free) will be discussed. We have examined the following areas: (1) genetically modified foods (GMOs); (2) food allergens; (3) microbiological contaminations; (4) food authenticity; (5) nutrigenetics/nutrigenomics.

  8. Disease-modifying antirheumatic drugs other than methotrexate in rheumatoid arthritis and seronegative arthritis.

    PubMed

    Nandi, Pradip; Kingsley, Gabrielle H; Scott, David L

    2008-05-01

    To outline recent research findings with nonmethotrexate disease-modifying antirheumatic drugs in rheumatoid arthritis and seronegative arthritis spanning systematic reviews, randomized controlled trials, observational clinical practice trials and assessments of adverse effects. Systematic reviews show no important differences between methotrexate, leflunomide and sulfasalazine monotherapies; early disease-modifying antirheumatic drug therapy reduces erosive progression. Observational studies show that nonmethotrexate disease-modifying antirheumatic drugs are widely prescribed; their usage has increased in the biologic era. A systemic review also showed patients who failed monotherapy benefited from disease-modifying antirheumatic drug combinations without excess toxicity. Randomized controlled trials of intensive initial disease-modifying antirheumatic drug combinations showed they reduce synovitis and erosive damage, especially when used with steroids. The subsequent sequence of disease-modifying antirheumatic drugs and the value of changing disease-modifying antirheumatic drug monotherapies or stepping-up to combination disease-modifying antirheumatic drugs are, however, unresolved. The adverse risks of nonmethotrexate disease-modifying antirheumatic drugs have been evaluated, including infections and lung disease; patient-related risks seem more important than drug-related risks, though several disease-modifying antirheumatic drugs increase both types of adverse reactions. Two limitations of nonmethotrexate disease-modifying antirheumatic drugs are reduced impact on comorbidities like cardiovascular disease and reduced patient and clinician preferences for these treatments. Nonmethotrexate disease-modifying antirheumatic drugs are effective, relatively well tolerated and widely used. Their role in intensive treatment strategies in early rheumatoid arthritis appears of crucial importance.

  9. Marfan Database (second edition): software and database for the analysis of mutations in the human FBN1 gene.

    PubMed Central

    Collod-Béroud, G; Béroud, C; Adès, L; Black, C; Boxer, M; Brock, D J; Godfrey, M; Hayward, C; Karttunen, L; Milewicz, D; Peltonen, L; Richards, R I; Wang, M; Junien, C; Boileau, C

    1997-01-01

    Fibrillin is the major component of extracellular microfibrils. Mutations in the fibrillin gene on chromosome 15 (FBN1) were described at first in the heritable connective tissue disorder, Marfan syndrome (MFS). More recently, FBN1 has also been shown to harbor mutations related to a spectrum of conditions phenotypically related to MFS. These mutations are private, essentially missense, generally non-recurrent and widely distributed throughout the gene. To date no clear genotype/phenotype relationship has been observed excepted for the localization of neonatal mutations in a cluster between exons 24 and 32. The second version of the computerized Marfan database contains 89 entries. The software has been modified to accomodate new functions and routines. PMID:9016526

  10. Ethnic Variation in Depressive Symptoms in a Community Sample in Hawai‘i

    PubMed Central

    Kanazawa, Asako; White, Patricia M.; Hampson, Sarah E.

    2008-01-01

    A modified CES-D was administered to a community sample of 176 European Americans (EA), 209 Native Hawaiians (NH), and 357 Japanese Americans (JA), yielding measures of depression, positive affect, depressed affect, somatic disturbance and disturbed interpersonal relations. Positive affect was lower in JA relative to EA, consistent with findings among Native Japanese, a pattern attributed to cultural variation in emotion regulation. NH reported lower positive affect than EA, accompanied by elevated negative affect and somatic disturbance, suggesting generally higher levels of depressive symptoms. The three ethnic groups varied in mental healthcare usage with differing associations between depressive symptoms and experiences of stressful life events. Taken together, these results suggest ethnic variation in depressive symptoms may arise from differing cultural beliefs. PMID:17227175

  11. Generalized sidelobe canceller beamforming method for ultrasound imaging.

    PubMed

    Wang, Ping; Li, Na; Luo, Han-Wu; Zhu, Yong-Kun; Cui, Shi-Gang

    2017-03-01

    A modified generalized sidelobe canceller (IGSC) algorithm is proposed to enhance the resolution and robustness against the noise of the traditional generalized sidelobe canceller (GSC) and coherence factor combined method (GSC-CF). In the GSC algorithm, weighting vector is divided into adaptive and non-adaptive parts, while the non-adaptive part does not block all the desired signal. A modified steer vector of the IGSC algorithm is generated by the projection of the non-adaptive vector on the signal space constructed by the covariance matrix of received data. The blocking matrix is generated based on the orthogonal complementary space of the modified steer vector and the weighting vector is updated subsequently. The performance of IGSC was investigated by simulations and experiments. Through simulations, IGSC outperformed GSC-CF in terms of spatial resolution by 0.1 mm regardless there is noise or not, as well as the contrast ratio respect. The proposed IGSC can be further improved by combining with CF. The experimental results also validated the effectiveness of the proposed algorithm with dataset provided by the University of Michigan.

  12. Chemically modified carbonic anhydrases useful in carbon capture systems

    DOEpatents

    Novick, Scott; Alvizo, Oscar

    2013-01-15

    The present disclosure relates to chemically modified carbonic anhydrase polypeptides and soluble compositions, homogenous liquid formulations comprising them. The chemically modified carbonic anhydrase polypeptides have improved properties relative to the same carbonic anhydrase polypeptide that is not chemically modified including the improved properties of increased activity and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides methods of preparing the chemically modified polypeptides and methods of using the chemically modified polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering.

  13. Chemically modified carbonic anhydrases useful in carbon capture systems

    DOEpatents

    Novick, Scott J; Alvizo, Oscar

    2013-10-29

    The present disclosure relates to chemically modified carbonic anhydrase polypeptides and soluble compositions, homogenous liquid formulations comprising them. The chemically modified carbonic anhydrase polypeptides have improved properties relative to the same carbonic anhydrase polypeptide that is not chemically modified including the improved properties of increased activity and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides methods of preparing the chemically modified polypeptides and methods of using the chemically modified polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering.

  14. Quantum fluctuation theorems and generalized measurements during the force protocol

    NASA Astrophysics Data System (ADS)

    Watanabe, Gentaro; Venkatesh, B. Prasanna; Talkner, Peter; Campisi, Michele; Hänggi, Peter

    2014-03-01

    Generalized measurements of an observable performed on a quantum system during a force protocol are investigated and conditions that guarantee the validity of the Jarzynski equality and the Crooks relation are formulated. In agreement with previous studies by M. Campisi, P. Talkner, and P. Hänggi [Phys. Rev. Lett. 105, 140601 (2010), 10.1103/PhysRevLett.105.140601; Phys. Rev. E 83, 041114 (2011), 10.1103/PhysRevE.83.041114], we find that these fluctuation relations are satisfied for projective measurements; however, for generalized measurements special conditions on the operators determining the measurements need to be met. For the Jarzynski equality to hold, the measurement operators of the forward protocol must be normalized in a particular way. The Crooks relation additionally entails that the backward and forward measurement operators depend on each other. Yet, quite some freedom is left as to how the two sets of operators are interrelated. This ambiguity is removed if one considers selective measurements, which are specified by a joint probability density function of work and measurement results of the considered observable. We find that the respective forward and backward joint probabilities satisfy the Crooks relation only if the measurement operators of the forward and backward protocols are the time-reversed adjoints of each other. In this case, the work probability density function conditioned on the measurement result satisfies a modified Crooks relation. The modification appears as a protocol-dependent factor that can be expressed by the information gained by the measurements during the forward and backward protocols. Finally, detailed fluctuation theorems with an arbitrary number of intervening measurements are obtained.

  15. Improving ECG Classification Accuracy Using an Ensemble of Neural Network Modules

    PubMed Central

    Javadi, Mehrdad; Ebrahimpour, Reza; Sajedin, Atena; Faridi, Soheil; Zakernejad, Shokoufeh

    2011-01-01

    This paper illustrates the use of a combined neural network model based on Stacked Generalization method for classification of electrocardiogram (ECG) beats. In conventional Stacked Generalization method, the combiner learns to map the base classifiers' outputs to the target data. We claim adding the input pattern to the base classifiers' outputs helps the combiner to obtain knowledge about the input space and as the result, performs better on the same task. Experimental results support our claim that the additional knowledge according to the input space, improves the performance of the proposed method which is called Modified Stacked Generalization. In particular, for classification of 14966 ECG beats that were not previously seen during training phase, the Modified Stacked Generalization method reduced the error rate for 12.41% in comparison with the best of ten popular classifier fusion methods including Max, Min, Average, Product, Majority Voting, Borda Count, Decision Templates, Weighted Averaging based on Particle Swarm Optimization and Stacked Generalization. PMID:22046232

  16. Longitudinal study of accelerated long-term forgetting in children with genetic generalized epilepsy: Evidence of ongoing deficits.

    PubMed

    Grayson-Collins, Jasmin; Gascoigne, Michael B; Barton, Belinda; Webster, Richard; Gill, Deepak; Lah, Suncica

    2017-09-15

    Accelerated long-term forgetting (ALF) is a recently described memory disorder characterised by adequate recall after short, but not long delays. Currently, the prevailing conceptualisation of ALF is of a seizure related phenomenon. The main aim of this study was to assess whether ALF subsides as epilepsy severity and seizures abate in children with genetic generalized epilepsy (GGE). Eighteen children with GGE were compared over time to 29 healthy controls on a range of cognitive measures. The primary outcome was a modified version of the California Verbal Learning Test for Children with a long delay (seven day) recall component. At approximately two years follow up, ALF was apparent, although epilepsy severity subsided and seizures resolved in many children. This result contrasts with the dominant conceptualisation of ALF being a seizure related phenomenon. Moreover, at follow-up, worse recall at the long delay was related to greater epilepsy severity at baseline and earlier age of seizure onset, but not to being seizure free at follow-up. While at follow-up worse recall at the long delay related to the worse baseline recall at the long delay, this recall did not relate to scores obtained on standardised memory tests at baseline. Our study suggests that ALF may not be seizure related and identifies factors associated with risk of ALF in children with GGE. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. A modified two-layer iteration via a boundary point approach to generalized multivalued pseudomonotone mixed variational inequalities.

    PubMed

    Saddeek, Ali Mohamed

    2017-01-01

    Most mathematical models arising in stationary filtration processes as well as in the theory of soft shells can be described by single-valued or generalized multivalued pseudomonotone mixed variational inequalities with proper convex nondifferentiable functionals. Therefore, for finding the minimum norm solution of such inequalities, the current paper attempts to introduce a modified two-layer iteration via a boundary point approach and to prove its strong convergence. The results here improve and extend the corresponding recent results announced by Badriev, Zadvornov and Saddeek (Differ. Equ. 37:934-942, 2001).

  18. Intermediate boundary conditions for LOD, ADI and approximate factorization methods

    NASA Technical Reports Server (NTRS)

    Leveque, R. J.

    1985-01-01

    A general approach to determining the correct intermediate boundary conditions for dimensional splitting methods is presented. The intermediate solution U is viewed as a second order accurate approximation to a modified equation. Deriving the modified equation and using the relationship between this equation and the original equation allows us to determine the correct boundary conditions for U*. This technique is illustrated by applying it to locally one dimensional (LOD) and alternating direction implicit (ADI) methods for the heat equation in two and three space dimensions. The approximate factorization method is considered in slightly more generality.

  19. Model-independent cosmological constraints from growth and expansion

    NASA Astrophysics Data System (ADS)

    L'Huillier, Benjamin; Shafieloo, Arman; Kim, Hyungjin

    2018-05-01

    Reconstructing the expansion history of the Universe from Type Ia supernovae data, we fit the growth rate measurements and put model-independent constraints on some key cosmological parameters, namely, Ωm, γ, and σ8. The constraints are consistent with those from the concordance model within the framework of general relativity, but the current quality of the data is not sufficient to rule out modified gravity models. Adding the condition that dark energy density should be positive at all redshifts, independently of its equation of state, further constrains the parameters and interestingly supports the concordance model.

  20. Radioprotection by Biological Response Modifiers Alone and in Combination with WR-2721

    DTIC Science & Technology

    1989-01-01

    reasons related to cancer therapy rather 247 CH2 OH CH 2OH CH 2 0H H H H OH H OH H OH H OH FI(; . Chemical structure of glucan . a polgl~can consisting...2. GLUCAN : BACKGROUND AND GENERAL IMMUNOLOGIC AND HEMOPOIETIC EFFECTS Glucan (Fig. 1) is a beta -l,3-polyglucose isolated from the inner cell wall of...Adju’an, Therapy. pp. 183- 194. CH iiGOS. M. A led ) Ra%.en Press. New York Ciop. J. K. and AtSTiN. K. F 11985) A beta - glucan inhibitable receptor on human

  1. New post-Newtonian parameter to test Chern-Simons gravity.

    PubMed

    Alexander, Stephon; Yunes, Nicolas

    2007-12-14

    We study Chern-Simons (CS) gravity in the parametrized post-Newtonian (PPN) framework through a weak-field solution of the modified field equations. We find that CS gravity possesses the same PPN parameters as general relativity, except for the inclusion of a new term, proportional to the CS coupling and the curl of the PPN vector potential. This new term leads to a modification of frame dragging and gyroscopic precession and we provide an estimate of its size. This correction might be used in experiments, such as Gravity Probe B, to bound CS gravity and test string theory.

  2. Topological photonic crystal with equifrequency Weyl points

    NASA Astrophysics Data System (ADS)

    Wang, Luyang; Jian, Shao-Kai; Yao, Hong

    2016-06-01

    Weyl points in three-dimensional photonic crystals behave as monopoles of Berry flux in momentum space. Here, based on general symmetry analysis, we show that a minimal number of four symmetry-related (consequently equifrequency) Weyl points can be realized in time-reversal invariant photonic crystals. We further propose an experimentally feasible way to modify double-gyroid photonic crystals to realize four equifrequency Weyl points, which is explicitly confirmed by our first-principle photonic band-structure calculations. Remarkably, photonic crystals with equifrequency Weyl points are qualitatively advantageous in applications including angular selectivity, frequency selectivity, invisibility cloaking, and three-dimensional imaging.

  3. The parameterization of the planetary boundary layer in the UCLA general circulation model - Formulation and results

    NASA Technical Reports Server (NTRS)

    Suarez, M. J.; Arakawa, A.; Randall, D. A.

    1983-01-01

    A planetary boundary layer (PBL) parameterization for general circulation models (GCMs) is presented. It uses a mixed-layer approach in which the PBL is assumed to be capped by discontinuities in the mean vertical profiles. Both clear and cloud-topped boundary layers are parameterized. Particular emphasis is placed on the formulation of the coupling between the PBL and both the free atmosphere and cumulus convection. For this purpose a modified sigma-coordinate is introduced in which the PBL top and the lower boundary are both coordinate surfaces. The use of a bulk PBL formulation with this coordinate is extensively discussed. Results are presented from a July simulation produced by the UCLA GCM. PBL-related variables are shown, to illustrate the various regimes the parameterization is capable of simulating.

  4. Electric fields and field-aligned currents in polar regions of the solar corona: 3-D MHD consideration

    NASA Technical Reports Server (NTRS)

    Pisanko, Yu. V.

    1995-01-01

    The calculation of the solar rotation electro-dynamical effects in the near-the-Sun solar wind seems more convenient from the non-inertial corotating reference frame. This implies some modification of the 3-D MHD equations generally on the base of the General Theory of Relativity. The paper deals with the search of stationary (in corotating non-inertial reference frame) solutions of the modified 3-D MHD equations for the in near-the-Sun high latitude sub-alfvenic solar wind. The solution is obtained requiring electric fields and field-aligned electric currents in the high latitude near-the-Sun solar wind. Various scenario are explored self-consistently via a number of numerical experiments. The analogy with the high latitude Earth's magnetosphere is used for the interpretation of the results. Possible observational manifestations are discussed.

  5. 29 CFR 553.3 - Coverage-general.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... definitions already in the Act were modified by the 1974 Amendments. The definition of the term “employer” was... public agencies. The definition of “enterprise” contained in section 3(r) of the Act was modified to... engaged in commerce or in the production of goods for commerce” defined in section 3(s) of the Act was...

  6. 78 FR 28671 - Self-Regulatory Organizations; Chicago Stock Exchange, Inc.; Notice of Filing and Immediate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-15

    ... Exchange also proposes to make corresponding grammatical amendments and technical amendments to improve... categories, as proposed paragraphs (a)-(g): (a) General Order Types; (b) Order Execution Modifiers; (c) Order... grammatical amendments. The purpose of this amendment is to clarify that an order execution modifier is not a...

  7. 47 CFR 97.21 - Application for a modified or renewed license grant.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE General Provisions § 97.21 Application for a modified or... name, club name, license trustee name, or license custodian name in accordance with § 1.913 of this chapter. For a club or military recreation station license grant, the application must be presented in...

  8. 47 CFR 97.21 - Application for a modified or renewed license grant.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE General Provisions § 97.21 Application for a modified or... name, club name, license trustee name, or license custodian name in accordance with § 1.913 of this chapter. For a club or military recreation station license grant, the application must be presented in...

  9. 47 CFR 97.21 - Application for a modified or renewed license grant.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE General Provisions § 97.21 Application for a modified or... name, club name, license trustee name, or license custodian name in accordance with § 1.913 of this chapter. For a club or military recreation station license grant, the application must be presented in...

  10. 47 CFR 97.21 - Application for a modified or renewed license grant.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE General Provisions § 97.21 Application for a modified or... name, club name, license trustee name or license custodian name in accordance with § 1.913 of this chapter. For a club, military recreation or RACES station license grant, it must be presented in document...

  11. 47 CFR 97.21 - Application for a modified or renewed license grant.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE General Provisions § 97.21 Application for a modified or... name, club name, license trustee name, or license custodian name in accordance with § 1.913 of this chapter. For a club or military recreation station license grant, the application must be presented in...

  12. Production of Jet Fuels from Coal Derived Liquids. Volume 1. Market Assessment for Liquid By-Products from the Great Plains Gasification Plant.

    DTIC Science & Technology

    1987-08-01

    synthesis gas from the gasification plant. This scheme was modified by changing the hydrogen generation step. Instead of the cryogenic separation it...Affairs ASD/PA) and is releasable to the National Technical Information Service NTIS). At NTIS, it will be available to the general public, including...58 Modified El Paso By-Products Schem 158 59 Modified El Paso Economics 158 60 Non-Hydrotreating El Paso Scheme 162 61 Non-Hydrotreating El Paso

  13. Overland flow connectivity on planar patchy hillslopes - modified percolation theory approaches and combinatorial model of urns

    NASA Astrophysics Data System (ADS)

    Nezlobin, David; Pariente, Sarah; Lavee, Hanoch; Sachs, Eyal

    2017-04-01

    Source-sink systems are very common in hydrology; in particular, some land cover types often generate runoff (e.g. embedded rocks, bare soil) , while other obstruct it (e.g. vegetation, cracked soil). Surface runoff coefficients of patchy slopes/plots covered by runoff generating and obstructing covers (e.g., bare soil and vegetation) depend critically on the percentage cover (i.e. sources/sinks abundance) and decrease strongly with observation scale. The classic mathematical percolation theory provides a powerful apparatus for describing the runoff connectivity on patchy hillslopes, but it ignores strong effect of the overland flow directionality. To overcome this and other difficulties, modified percolation theory approaches can be considered, such as straight percolation (for the planar slopes), quasi-straight percolation and models with limited obstruction. These approaches may explain both the observed critical dependence of runoff coefficients on percentage cover and their scale decrease in systems with strong flow directionality (e.g. planar slopes). The contributing area increases sharply when the runoff generating percentage cover approaches the straight percolation threshold. This explains the strong increase of the surface runoff and erosion for relatively low values (normally less than 35%) of the obstructing cover (e.g., vegetation). Combinatorial models of urns with restricted occupancy can be applied for the analytic evaluation of meaningful straight percolation quantities, such as NOGA's (Non-Obstructed Generating Area) expected value and straight percolation probability. It is shown that the nature of the cover-related runoff scale decrease is combinatorial - the probability for the generated runoff to avoid obstruction in unit area decreases with scale for the non-trivial percentage cover values. The magnitude of the scale effect is found to be a skewed non-monotonous function of the percentage cover. It is shown that the cover-related scale effect becomes less prominent if the obstructing capacity decreases, as generally occurs during heavy rainfalls. The plot width have a moderate positive statistical effect on runoff and erosion coefficients, since wider patchy plots have, on average, a greater normalized contributing area and a higher probability to have runoff of a certain length. The effect of plot width depends by itself on the percentage cover, plot length, and compared width scales. The contributing area uncertainty brought about by cover spatial arrangement is examined, including its dependence on the percentage cover and scale. In general, modified percolation theory approaches and combinatorial models of urns with restricted occupancy may link between critical dependence of runoff on percentage cover, cover-related scale effect, and statistical uncertainty of the observed quantities.

  14. Current stress and poor oral health.

    PubMed

    Vasiliou, A; Shankardass, K; Nisenbaum, R; Quiñonez, C

    2016-09-02

    Psychological stress appears to contribute to poor oral health systemically in combination with other chronic diseases. Few studies directly examine this relationship. Data from a cross-sectional study of 2,412 participants between the ages of 25-64 years old living in the City of Toronto between 2009 and 2012 were used to examine the relationship between current stress and two self-rated oral health outcomes (general oral health and oral pain). Dental care utilization and access to dental insurance were examined as effect modifiers. A positive relationship between current stress and poor oral health was observed for both outcomes (oral pain coefficient 0.32, 95 % CI 0.26-0.38; general oral health coefficient 0.28, 95 % CI 0.19-0.36). Effects on oral pain were stronger for the uninsured, while effects on general oral health were stronger with decreasing socioeconomic position. Our findings suggest that individuals with greater perceived stress also report poorer oral health, and that this relationship is modified by dental insurance and socioeconomic position. These findings warrant a greater focus on the role of psychological stress in the development of oral disease, including how perceived stress contributes to health inequities in self-reported oral health status. Patients experiencing stressful lives may differentially require closer monitoring and more vigilant maintenance of their oral health, above and beyond that which is needed to achieve a state of health in the oral environment of less stressed individuals. There may be health promoting effects of addressing psychosocial concerns related to dental care - particularly for the poor and uninsured.

  15. Neutron star mass-radius relation with gravitational field shielding by a scalar field

    NASA Astrophysics Data System (ADS)

    Zhang, Bo-Jun; Zhang, Tian-Xi; Guggilla, Padmaja; Dokhanian, Mostafa

    2013-05-01

    The currently well-developed models for equations of state (EoSs) have been severely impacted by recent measurements of neutron stars with a small radius and/or large mass. To explain these measurements, the theory of gravitational field shielding by a scalar field is applied. This theory was recently developed in accordance with the five-dimensional (5D) fully covariant Kaluza-Klein (KK) theory that has successfully unified Einstein's general relativity and Maxwell's electromagnetic theory. It is shown that a massive, compact neutron star can generate a strong scalar field, which can significantly shield or reduce its gravitational field, thus making it more massive and more compact. The mass-radius relation developed under this type of modified gravity can be consistent with these recent measurements of neutron stars. In addition, the effect of gravitational field shielding helps explain why the supernova explosions of some very massive stars (e.g., 40 Msolar as measured recently) actually formed neutron stars rather than black holes as expected. The EoS models, ruled out by measurements of small radius and/or large mass neutron stars according to the theory of general relativity, can still work well in terms of the 5D fully covariant KK theory with a scalar field.

  16. On the hyperbolicity and stability of 3+1 formulations of metric f( R) gravity

    NASA Astrophysics Data System (ADS)

    Mongwane, Bishop

    2016-11-01

    3+1 formulations of the Einstein field equations have become an invaluable tool in Numerical relativity, having been used successfully in modeling spacetimes of black hole collisions, stellar collapse and other complex systems. It is plausible that similar considerations could prove fruitful for modified gravity theories. In this article, we pursue from a numerical relativistic viewpoint the 3+1 formulation of metric f( R) gravity as it arises from the fourth order equations of motion, without invoking the dynamical equivalence with Brans-Dicke theories. We present the resulting system of evolution and constraint equations for a generic function f( R), subject to the usual viability conditions. We confirm that the time propagation of the f( R) Hamiltonian and Momentum constraints take the same Mathematical form as in general relativity, irrespective of the f( R) model. We further recast the 3+1 system in a form akin to the BSSNOK formulation of numerical relativity. Without assuming any specific model, we show that the ADM version of f( R) is weakly hyperbolic and is plagued by similar zero speed modes as in the general relativity case. On the other hand the BSSNOK version is strongly hyperbolic and hence a promising formulation for numerical simulations in metric f( R) theories.

  17. Parents' assessment of circadian preference in elementary school-aged children: Validity and relations to educational outcomes.

    PubMed

    Scherrer, Vsevolod; Roberts, Richard; Preckel, Franzis

    2016-01-01

    Meta-analyses suggest that morning-oriented students obtain better school grades than evening-oriented students. This finding has generally been found for students in high school using self-report data for the assessment of circadian preference. Two studies (N = 2718/192) investigated whether these findings generalize across samples (i.e. elementary school-aged students) and methods (i.e. parent reports). These studies also explored whether the relation between circadian preference and school achievement could be explained within an expectancy-value framework. To this end, the Lark-Owl Chronotype Indicator (LOCI) was modified to obtain parents' evaluations of their children's circadian preference, while students completed a battery of assessments designed to explore the test-criterion evidence. Structural equation modeling and correlational analyses revealed: (1) morning and evening orientation were two separable factors of children's circadian preference; (2) correlations with behavioral (e.g. sleep and eating times) and psychological (e.g. cognitive ability) data supported the test-criterion validity of both factors; (3) morning orientation was positively related to school achievement and (4) consistent with an expectancy-value framework this relation was mediated by children's academic self-concept (ASC). These findings have important research and policy implications for considering circadian preference in the schooling of elementary students.

  18. Hoarding and emotional reactivity: the link between negative emotional reactions and hoarding symptomatology.

    PubMed

    Shaw, A M; Timpano, K R; Steketee, G; Tolin, D F; Frost, R O

    2015-04-01

    Hoarding disorder (HD) is characterized by difficulty discarding, clutter, and frequently excessive acquiring. Theories have pointed to intense negative emotional reactions (e.g., sadness) as one factor that may play a critical role in HD's etiology. Preliminary work with an analogue sample indicated that more intense negative emotions following emotional films were linked with greater hoarding symptoms. Symptom provocation imaging studies with HD patients have also found evidence for excessive activation in brain regions implicated in processing emotions. The current study utilized a sample with self-reported serious hoarding difficulties to examine how hoarding symptoms related to both general and hoarding-related emotional reactivity, taking into account the specificity of these relationships. We also examined how two cognitive factors, fear of decision-making and confidence in memory, modified this relationship. 628 participants with self-identified hoarding difficulties completed questionnaires about general emotional reactivity, depression, anxiety, decision-making, and confidence in memory. To assess hoarding-related emotional reactivity, participants reported their emotional reactions when imagining discarding various items. Heightened general emotional reactivity and more intense emotional reactions to imagined discarding were associated with both difficulty discarding and acquisition, but not clutter, controlling for age, gender, and co-occurring mood and anxiety symptoms. Fear of decision-making and confidence in memory interacted with general emotional reactivity to predict hoarding symptoms. These findings provide support for cognitive-behavioral models of hoarding. Experimental research should be conducted to discover whether emotional reactivity increases vulnerability for HD. Future work should also examine whether emotional reactivity should be targeted in interventions for hoarding. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Hoarding and emotional reactivity: The link between negative emotional reactions and hoarding symptomatology

    PubMed Central

    Shaw, A.M.; Timpano, K.R.; Steketee, G.; Tolin, D. F.; Frost, R.O.

    2015-01-01

    Hoarding disorder (HD) is characterized by difficulty discarding, clutter, and frequently excessive acquiring. Theories have pointed to intense negative emotional reactions (e.g., sadness) as one factor that may play a critical role in HD’s etiology. Preliminary work with an analogue sample indicated that more intense negative emotions following emotional films were linked with greater hoarding symptoms. Symptom provocation imaging studies with HD patients have also found evidence for excessive activation in brain regions implicated in processing emotions. The current study utilized a sample with self-reported serious hoarding difficulties to examine how hoarding symptoms related to both general and hoarding-related emotional reactivity, taking into account the specificity of these relationships. We also examined how two cognitive factors, fear of decision-making and confidence in memory, modified this relationship. 628 participants with self-identified hoarding difficulties completed questionnaires about general emotional reactivity, depression, anxiety, decision-making, and confidence in memory. To assess hoarding-related emotional reactivity, participants reported their emotional reactions when imagining discarding various items. Heightened general emotional reactivity and more intense emotional reactions to imagined discarding were associated with both difficulty discarding and acquisition, but not clutter, controlling for age, gender, and co-occurring mood and anxiety symptoms. Fear of decision-making and confidence in memory interacted with general emotional reactivity to predict hoarding symptoms. These findings provide support for cognitive-behavioral models of hoarding. Experimental research should be conducted to discover whether emotional reactivity increases vulnerability for HD. Future work should also examine whether emotional reactivity should be targeted in interventions for hoarding. PMID:25732668

  20. Modifying gravity: you cannot always get what you want.

    PubMed

    Starkman, Glenn D

    2011-12-28

    The combination of general relativity (GR) and the Standard Model of particle physics disagrees with numerous observations on scales from our Solar System up. In the canonical concordance model of Lambda cold dark matter (ΛCDM) cosmology, many of these contradictions between theory and data are removed or alleviated by the introduction of three completely independent new components of stress energy--the inflaton, dark matter and dark energy. Each of these in its turn is meant to have dominated (or to currently dominate) the dynamics of the Universe. There is, until now, no non-gravitational evidence for any of these dark sectors, nor is there evidence (though there may be motivation) for the required extension of the Standard Model. An alternative is to imagine that it is GR that must be modified to account for some or all of these disagreements. Certain coincidences of scale even suggest that one might expect not to make independent modifications of the theory to replace each of the three dark sectors. Because they must address the most different types of data, attempts to replace dark matter with modified gravity are the most controversial. A phenomenological model (or family of models), modified Newtonian dynamics, has, over the last few years, seen several covariant realizations. We discuss a number of challenges that any model that seeks to replace dark matter with modified gravity must face: the loss of Birkhoff's theorem, and the calculational simplifications it implies; the failure to explain clusters, whether static or interacting, and the consequent need to introduce dark matter of some form, whether hot dark matter neutrinos or dark fields that arise in new sectors of the modified gravity theory; the intrusion of cosmological expansion into the modified force law, which arises precisely because of the coincidence in scale between the centripetal acceleration at which Newtonian gravity fails in galaxies and the cosmic acceleration. We conclude with the observation that, although modified gravity may indeed manage to replace dark matter, it is likely to do so by becoming or at least incorporating a dark matter theory itself.

  1. Structural and dynamic properties of liquid tin from a new modified embedded-atom method force field

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vella, Joseph R.; Chen, Mohan; Stillinger, Frank H.

    We developed a new modified embedded-atom method (MEAM) force field for liquid tin. Starting from the Ravelo and Baskes force field [Phys. Rev. Lett. 79, 2482 (1997)], the parameters are adjusted using a simulated annealing optimization procedure in order to obtain better agreement with liquid-phase data. The predictive capabilities of the new model and the Ravelo and Baskes force field are evaluated using molecular dynamics by comparing to a wide range of first-principles and experimental data. The quantities studied include crystal properties (cohesive energy, bulk modulus, equilibrium density, and lattice constant of various crystal structures), melting temperature, liquid structure, liquidmore » density, self-diffusivity, viscosity, and vapor-liquid surface tension. We show that although the Ravelo and Baskes force field generally gives better agreement with the properties related to the solid phases of tin, the new MEAM force field gives better agreement with liquid tin properties.« less

  2. Acquisition of a visual discrimination and reversal learning task by Labrador retrievers.

    PubMed

    Lazarowski, Lucia; Foster, Melanie L; Gruen, Margaret E; Sherman, Barbara L; Case, Beth C; Fish, Richard E; Milgram, Norton W; Dorman, David C

    2014-05-01

    Optimal cognitive ability is likely important for military working dogs (MWD) trained to detect explosives. An assessment of a dog's ability to rapidly learn discriminations might be useful in the MWD selection process. In this study, visual discrimination and reversal tasks were used to assess cognitive performance in Labrador retrievers selected for an explosives detection program using a modified version of the Toronto General Testing Apparatus (TGTA), a system developed for assessing performance in a battery of neuropsychological tests in canines. The results of the current study revealed that, as previously found with beagles tested using the TGTA, Labrador retrievers (N = 16) readily acquired both tasks and learned the discrimination task significantly faster than the reversal task. The present study confirmed that the modified TGTA system is suitable for cognitive evaluations in Labrador retriever MWDs and can be used to further explore effects of sex, phenotype, age, and other factors in relation to canine cognition and learning, and may provide an additional screening tool for MWD selection.

  3. Bouncing cosmologies via modified gravity in the ADM formalism: Application to loop quantum cosmology

    NASA Astrophysics Data System (ADS)

    de Haro, Jaume; Amorós, Jaume

    2018-03-01

    We consider the Arnowitt-Deser-Misner formalism as a tool to build bouncing cosmologies. In this approach, the foliation of the spacetime has to be fixed in order to go beyond general relativity modifying the gravitational sector. Once a preferred slicing, which we choose based on the matter content of the Universe following the spirit of Weyl's postulate, has been fixed, f theories depending on the extrinsic and intrinsic curvature of the slicing are covariant for all the reference frames preserving the foliation; i.e., the constraint and dynamical equations have the same form for all these observers. Moreover, choosing multivalued f functions, bouncing backgrounds emerge in a natural way. In fact, the simplest is the one corresponding to holonomy corrected loop quantum cosmology. The final goal of this work is to provide the equations of perturbations which, unlike the full equations, become gauge invariant in this theory, and apply them to the so-called matter bounce scenario.

  4. Changes in mood status and neurotic levels during a 20-day bed rest

    NASA Astrophysics Data System (ADS)

    Ishizaki, Yuko; Ishizaki, Tatsuro; Fukuoka, Hideoki; Kim, Chang-Sun; Fujita, Masayo; Maegawa, Yuko; Fujioka, Hiroshi; Katsura, Taisaku; Suzuki, Yoji; Gunji, Atsuaki

    2002-04-01

    This study evaluated changes of mood status and depressive and neurotic levels in nine young male subjects during a 20-day 6° head-down tilting bed rest and examined whether exercise training modified these changes. Participants were asked to complete psychometrical inventories on before, during, and after the bed rest experiment. Depressive and neurotic levels were enhanced during bed rest period according to the Japanese version of Zung's Self-rating Depression Scale and the Japanese version of the General Health Questionnaire. Mood state "vigor" was impaired and "confusion" was increased during bed rest and recumbent control periods compared to pre-bed rest and ambulatory control periods according to the Japanese version of Profiles of Mood State, whereas the mood "tension-anxiety", "depression-dejection", "anger-hostility" and "fatigue" were relatively stable during experiment. Isometric exercise training did not modify these results. Microgravity, along with confinement to bed and isolation from familiar environments, induced impairment of mental status.

  5. Structural and dynamic properties of liquid tin from a new modified embedded-atom method force field

    NASA Astrophysics Data System (ADS)

    Vella, Joseph R.; Chen, Mohan; Stillinger, Frank H.; Carter, Emily A.; Debenedetti, Pablo G.; Panagiotopoulos, Athanassios Z.

    2017-02-01

    A new modified embedded-atom method (MEAM) force field is developed for liquid tin. Starting from the Ravelo and Baskes force field [Phys. Rev. Lett. 79, 2482 (1997), 10.1103/PhysRevLett.79.2482], the parameters are adjusted using a simulated annealing optimization procedure in order to obtain better agreement with liquid-phase data. The predictive capabilities of the new model and the Ravelo and Baskes force field are evaluated using molecular dynamics by comparing to a wide range of first-principles and experimental data. The quantities studied include crystal properties (cohesive energy, bulk modulus, equilibrium density, and lattice constant of various crystal structures), melting temperature, liquid structure, liquid density, self-diffusivity, viscosity, and vapor-liquid surface tension. It is shown that although the Ravelo and Baskes force field generally gives better agreement with the properties related to the solid phases of tin, the new MEAM force field gives better agreement with liquid tin properties.

  6. Toward Realistic Simulation of low-Level Clouds Using a Multiscale Modeling Framework With a Third-Order Turbulence Closure in its Cloud-Resolving Model Component

    NASA Technical Reports Server (NTRS)

    Xu, Kuan-Man; Cheng, Anning

    2010-01-01

    This study presents preliminary results from a multiscale modeling framework (MMF) with an advanced third-order turbulence closure in its cloud-resolving model (CRM) component. In the original MMF, the Community Atmosphere Model (CAM3.5) is used as the host general circulation model (GCM), and the System for Atmospheric Modeling with a first-order turbulence closure is used as the CRM for representing cloud processes in each grid box of the GCM. The results of annual and seasonal means and diurnal variability are compared between the modified and original MMFs and the CAM3.5. The global distributions of low-level cloud amounts and precipitation and the amounts of low-level clouds in the subtropics and middle-level clouds in mid-latitude storm track regions in the modified MMF show substantial improvement relative to the original MMF when both are compared to observations. Some improvements can also be seen in the diurnal variability of precipitation.

  7. The Role of Social Connectedness and Sexual Orientation in the Prevention of Youth Suicide Ideation and Attempts Among Sexually Active Adolescents.

    PubMed

    Stone, Deborah M; Luo, Feijun; Lippy, Caroline; McIntosh, Wendy LiKamWa

    2015-08-01

    The impact of types of social connectedness-family, other adult, and school-on suicide ideation and attempts among all youth, the relative impact of each type, and effect modification by sexual orientation was assessed. Data were from the 2007-2009 Milwaukee Youth Risk Behavior Surveys. Multivariable logistic regression analyses calculated the risk of suicide ideation and attempts by sexual orientation, types of social connectedness, and their interaction. Among all youth, each type of connectedness modeled singly conferred protective effects for suicide ideation. Family and other adult connectedness protected against suicide attempts. When modeled simultaneously, family connectedness protected against ideation and attempts. Sexual orientation modified the association between other adult connectedness and suicide ideation. Findings suggest that family connectedness confers the most consistent protection among all youth and sexual orientation does not generally modify the association between connectedness and suicidal behavior. © Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  8. Customizing laboratory mice by modifying gut microbiota and host immunity in an early "window of opportunity".

    PubMed

    Hansen, Camilla H F; Metzdorff, Stine B; Hansen, Axel K

    2013-01-01

    We recently investigated how post-natal microbial gut colonization is important for the development of the immune system, especially in the systemic compartments. This addendum presents additional data which in accordance with our previous findings show that early life microbial colonization is critical for a fine-tuned immune homeostasis to develop also in the intestinal environment. A generalized reduction in the expression of immune signaling related genes in the small intestine may explain previously shown increased systemic adaptive immune reactivity, if the regulatory cross-talk between intra- and extra-intestinal immune cells is immature following a neonatal germ-free period. These findings are furthermore discussed in the context of recently published results on how lack of microbial exposure in the neonatal life modifies disease expression in rodents used as models mimicking human inflammatory diseases. In particular, with a focus on how these interesting findings could be used to optimize the use of rodent models.

  9. Structural and dynamic properties of liquid tin from a new modified embedded-atom method force field

    DOE PAGES

    Vella, Joseph R.; Chen, Mohan; Stillinger, Frank H.; ...

    2017-02-01

    We developed a new modified embedded-atom method (MEAM) force field for liquid tin. Starting from the Ravelo and Baskes force field [Phys. Rev. Lett. 79, 2482 (1997)], the parameters are adjusted using a simulated annealing optimization procedure in order to obtain better agreement with liquid-phase data. The predictive capabilities of the new model and the Ravelo and Baskes force field are evaluated using molecular dynamics by comparing to a wide range of first-principles and experimental data. The quantities studied include crystal properties (cohesive energy, bulk modulus, equilibrium density, and lattice constant of various crystal structures), melting temperature, liquid structure, liquidmore » density, self-diffusivity, viscosity, and vapor-liquid surface tension. We show that although the Ravelo and Baskes force field generally gives better agreement with the properties related to the solid phases of tin, the new MEAM force field gives better agreement with liquid tin properties.« less

  10. Emergent cosmology revisited

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bag, Satadru; Sahni, Varun; Shtanov, Yuri

    We explore the possibility of emergent cosmology using the effective potential formalism. We discover new models of emergent cosmology which satisfy the constraints posed by the cosmic microwave background (CMB). We demonstrate that, within the framework of modified gravity, the emergent scenario can arise in a universe which is spatially open/closed. By contrast, in general relativity (GR) emergent cosmology arises from a spatially closed past-eternal Einstein Static Universe (ESU). In GR the ESU is unstable, which creates fine tuning problems for emergent cosmology. However, modified gravity models including Braneworld models, Loop Quantum Cosmology (LQC) and Asymptotically Free Gravity result inmore » a stable ESU. Consequently, in these models emergent cosmology arises from a larger class of initial conditions including those in which the universe eternally oscillates about the ESU fixed point. We demonstrate that such an oscillating universe is necessarily accompanied by graviton production. For a large region in parameter space graviton production is enhanced through a parametric resonance, casting serious doubts as to whether this emergent scenario can be past-eternal.« less

  11. An exact solution for a rotating black hole in modified gravity

    NASA Astrophysics Data System (ADS)

    Filippini, Francesco; Tasinato, Gianmassimo

    2018-01-01

    Exact solutions describing rotating black holes can offer important tests for alternative theories of gravity, motivated by the dark energy and dark matter problems. We present an analytic rotating black hole solution for a class of vector-tensor theories of modified gravity, valid for arbitrary values of the rotation parameter. The new configuration is characterised by parametrically large deviations from the Kerr-Newman geometry, controlled by non-minimal couplings between vectors and gravity. It has an oblate horizon in Boyer-Lindquist coordinates, and it can rotate more rapidly and have a larger ergosphere than black holes in General Relativity (GR) with the same asymptotic properties. We analytically investigate the features of the innermost stable circular orbits for massive objects on the equatorial plane, and show that stable orbits lie further away from the black hole horizon with respect to rotating black holes in GR. We also comment on possible applications of our findings for the extraction of rotational energy from the black hole.

  12. A marked correlation function for constraining modified gravity models

    NASA Astrophysics Data System (ADS)

    White, Martin

    2016-11-01

    Future large scale structure surveys will provide increasingly tight constraints on our cosmological model. These surveys will report results on the distance scale and growth rate of perturbations through measurements of Baryon Acoustic Oscillations and Redshift-Space Distortions. It is interesting to ask: what further analyses should become routine, so as to test as-yet-unknown models of cosmic acceleration? Models which aim to explain the accelerated expansion rate of the Universe by modifications to General Relativity often invoke screening mechanisms which can imprint a non-standard density dependence on their predictions. This suggests density-dependent clustering as a `generic' constraint. This paper argues that a density-marked correlation function provides a density-dependent statistic which is easy to compute and report and requires minimal additional infrastructure beyond what is routinely available to such survey analyses. We give one realization of this idea and study it using low order perturbation theory. We encourage groups developing modified gravity theories to see whether such statistics provide discriminatory power for their models.

  13. Children and genetically engineered food: potentials and problems.

    PubMed

    Perr, Hilary A

    2002-10-01

    Changes in food production and dietary practices are occurring faster than our understanding of their potential impact on children's health. Traditionally, pediatric gastroenterologists have studied food with respect to its nutritive value and digestibility, its influence on metabolism, its growth-promoting characteristics, and its relationship to risk and severity of disease. Biotechnology is now expanding the science of food to include disease prevention and treatment, as well as the feeding of children on a global scale. Bioengineered ("genetically modified", or "transgenic") plants were initially developed to enhance the food supply by increasing crop yields. Such previously developed transgenic plants are now prevalent worldwide and appear in many processed food products. The implementation of the technology of genetic modulation of food plants has led to considerable fear, controversy, and confusion as the understanding of the technology is poor in the general population. This review presents an overview of genetically modified food crops and their potential unique benefits and risks to children's health. Political, economical, and ecological issues related to transgenic crops are not discussed.

  14. Analysis and design of a six-degree-of-freedom Stewart platform-based robotic wrist

    NASA Technical Reports Server (NTRS)

    Nguyen, Charles C.; Antrazi, Sami; Zhou, Zhen-Lei

    1991-01-01

    The kinematic analysis and implementation of a six degree of freedom robotic wrist which is mounted to a general open-kinetic chain manipulator to serve as a restbed for studying precision robotic assembly in space is discussed. The wrist design is based on the Stewart Platform mechanism and consists mainly of two platforms and six linear actuators driven by DC motors. Position feedback is achieved by linear displacement transducers mounted along the actuators and force feedback is obtained by a 6 degree of freedom force sensor mounted between the gripper and the payload platform. The robot wrist inverse kinematics which computes the required actuator lengths corresponding to Cartesian variables has a closed-form solution. The forward kinematics is solved iteratively using the Newton-Ralphson method which simultaneously provides a modified Jacobian Matrix which relates length velocities to Cartesian translational velocities and time rates of change of roll-pitch-yaw angles. Results of computer simulation conducted to evaluate the efficiency of the forward kinematics and Modified Jacobian Matrix are discussed.

  15. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kaothekar, Sachin, E-mail: sackaothekar@gmail.com

    I have studied the effects of finite electron inertia, finite ion Larmor radius (FLR) corrections, and radiative heat-loss function on the thermal instability of an infinite homogeneous, viscous plasma incorporating the effect of thermal conductivity for star formation in interstellar medium (ISM). A general dispersion relation is derived using the normal mode analysis method with the help of relevant linearized perturbation equations of the problem. The wave propagation is discussed for longitudinal and transverse directions to the external magnetic field and the conditions of modified thermal instabilities and stabilities are discussed in different cases. We find that the thermal instabilitymore » criterion is get modified into radiative instability criterion by inclusion of radiative heat-loss functions with thermal conductivity. The viscosity of medium removes the effect of FLR corrections from the condition of radiative instability. Numerical calculation shows stabilizing effect of heat-loss function, viscosity and FLR corrections, and destabilizing effect of finite electron inertia on the thermal instability. Results carried out in this paper shows that stars are formed in interstellar medium mainly due to thermal instability.« less

  16. Generalized Galileons: instabilities of bouncing and Genesis cosmologies and modified Genesis

    NASA Astrophysics Data System (ADS)

    Libanov, M.; Mironov, S.; Rubakov, V.

    2016-08-01

    We study spatially flat bouncing cosmologies and models with the early-time Genesis epoch in a popular class of generalized Galileon theories. We ask whether there exist solutions of these types which are free of gradient and ghost instabilities. We find that irrespectively of the forms of the Lagrangian functions, the bouncing models either are plagued with these instabilities or have singularities. The same result holds for the original Genesis model and its variants in which the scale factor tends to a constant as t → -∞. The result remains valid in theories with additional matter that obeys the Null Energy Condition and interacts with the Galileon only gravitationally. We propose a modified Genesis model which evades our no-go argument and give an explicit example of healthy cosmology that connects the modified Genesis epoch with kination (the epoch still driven by the Galileon field, which is a conventional massless scalar field at that stage).

  17. Velocity boundary conditions for vorticity formulations of the incompressible Navier-Stokes equations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kempka, S.N.; Strickland, J.H.; Glass, M.W.

    1995-04-01

    formulation to satisfy velocity boundary conditions for the vorticity form of the incompressible, viscous fluid momentum equations is presented. The tangential and normal components of the velocity boundary condition are satisfied simultaneously by creating vorticity adjacent to boundaries. The newly created vorticity is determined using a kinematical formulation which is a generalization of Helmholtz` decomposition of a vector field. Though it has not been generally recognized, these formulations resolve the over-specification issue associated with creating voracity to satisfy velocity boundary conditions. The generalized decomposition has not been widely used, apparently due to a lack of a useful physical interpretation. Anmore » analysis is presented which shows that the generalized decomposition has a relatively simple physical interpretation which facilitates its numerical implementation. The implementation of the generalized decomposition is discussed in detail. As an example the flow in a two-dimensional lid-driven cavity is simulated. The solution technique is based on a Lagrangian transport algorithm in the hydrocode ALEGRA. ALEGRA`s Lagrangian transport algorithm has been modified to solve the vorticity transport equation and the generalized decomposition, thus providing a new, accurate method to simulate incompressible flows. This numerical implementation and the new boundary condition formulation allow vorticity-based formulations to be used in a wider range of engineering problems.« less

  18. A general solution strategy of modified power method for higher mode solutions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Peng; Lee, Hyunsuk; Lee, Deokjung, E-mail: deokjung@unist.ac.kr

    2016-01-15

    A general solution strategy of the modified power iteration method for calculating higher eigenmodes has been developed and applied in continuous energy Monte Carlo simulation. The new approach adopts four features: 1) the eigen decomposition of transfer matrix, 2) weight cancellation for higher modes, 3) population control with higher mode weights, and 4) stabilization technique of statistical fluctuations using multi-cycle accumulations. The numerical tests of neutron transport eigenvalue problems successfully demonstrate that the new strategy can significantly accelerate the fission source convergence with stable convergence behavior while obtaining multiple higher eigenmodes at the same time. The advantages of the newmore » strategy can be summarized as 1) the replacement of the cumbersome solution step of high order polynomial equations required by Booth's original method with the simple matrix eigen decomposition, 2) faster fission source convergence in inactive cycles, 3) more stable behaviors in both inactive and active cycles, and 4) smaller variances in active cycles. Advantages 3 and 4 can be attributed to the lower sensitivity of the new strategy to statistical fluctuations due to the multi-cycle accumulations. The application of the modified power method to continuous energy Monte Carlo simulation and the higher eigenmodes up to 4th order are reported for the first time in this paper. -- Graphical abstract: -- Highlights: •Modified power method is applied to continuous energy Monte Carlo simulation. •Transfer matrix is introduced to generalize the modified power method. •All mode based population control is applied to get the higher eigenmodes. •Statistic fluctuation can be greatly reduced using accumulated tally results. •Fission source convergence is accelerated with higher mode solutions.« less

  19. Dietary Protein Modifies the Effect of the MC4R Genotype on 2-Year Changes in Appetite and Food Craving: The POUNDS Lost Trial123

    PubMed Central

    Huang, Tao; Zheng, Yan; Hruby, Adela; Williamson, Donald A; Bray, George A; Shen, Yiru; Sacks, Frank M; Qi, Lu

    2017-01-01

    Background: The melanocortin-4 receptor (MC4R) plays a pivotal role in the regulation of appetite and eating behavior. Variants in the MC4R gene have been related to appetite and obesity. Objective: We aimed to examine whether weight-loss diets modified the effect of the “obesity-predisposing” MC4R genotype on appetite-related measures in a randomized controlled trial. Methods: A total of 811 overweight and obese subjects [25 ≤ body mass index (BMI; kg/m2) ≤ 40] aged 30–70 y were included in the 2-y POUNDS Lost (Preventing Overweight Using Novel Dietary Strategies) trial. We genotyped MC4R rs7227255 in 735 overweight adults and assessed appetite-related characteristics, including craving, fullness, hunger, and prospective consumption, as well as a composite appetite score. We examined the effects of the genotype-by-weight-loss diet intervention interaction on appetite variables by using general linear models in both the whole population and in white participants only. Results: We found that dietary protein intake (low compared with high: 15% of energy compared with 25% of energy, respectively) significantly modified MC4R genetic effects on changes in appetite score and craving (P-interaction = 0.03 and 0.02, respectively) at 2 y, after adjustment for age, sex, ethnicity, baseline BMI, weight change, and baseline perspective phenotype. The obesity-predisposing A allele was associated with a greater increase in overall appetite score (β = 0.10, P = 0.05) and craving (β = 0.13, P = 0.008) compared with the non-A allele among participants who consumed a high-protein diet. MC4R genotype did not modify the effects of fat or carbohydrate intakes on appetite measures. Similar interaction patterns were observed in whites. Conclusion: Our data suggest that individuals with the MC4R rs7227255 A allele rather than the non-A allele might experience greater increases in appetite and food craving when consuming a high-protein weight-loss diet. This trial was registered at clinicaltrials.gov as NCT00072995. PMID:28148682

  20. Dietary Protein Modifies the Effect of the MC4R Genotype on 2-Year Changes in Appetite and Food Craving: The POUNDS Lost Trial.

    PubMed

    Huang, Tao; Zheng, Yan; Hruby, Adela; Williamson, Donald A; Bray, George A; Shen, Yiru; Sacks, Frank M; Qi, Lu

    2017-03-01

    Background: The melanocortin-4 receptor (MC4R) plays a pivotal role in the regulation of appetite and eating behavior. Variants in the MC4R gene have been related to appetite and obesity. Objective: We aimed to examine whether weight-loss diets modified the effect of the "obesity-predisposing" MC4R genotype on appetite-related measures in a randomized controlled trial. Methods: A total of 811 overweight and obese subjects [25 ≤ body mass index (BMI; kg/m 2 ) ≤ 40] aged 30-70 y were included in the 2-y POUNDS Lost (Preventing Overweight Using Novel Dietary Strategies) trial. We genotyped MC4R rs7227255 in 735 overweight adults and assessed appetite-related characteristics, including craving, fullness, hunger, and prospective consumption, as well as a composite appetite score. We examined the effects of the genotype-by-weight-loss diet intervention interaction on appetite variables by using general linear models in both the whole population and in white participants only. Results: We found that dietary protein intake (low compared with high: 15% of energy compared with 25% of energy, respectively) significantly modified MC4R genetic effects on changes in appetite score and craving ( P -interaction = 0.03 and 0.02, respectively) at 2 y, after adjustment for age, sex, ethnicity, baseline BMI, weight change, and baseline perspective phenotype. The obesity-predisposing A allele was associated with a greater increase in overall appetite score (β = 0.10, P = 0.05) and craving (β = 0.13, P = 0.008) compared with the non-A allele among participants who consumed a high-protein diet. MC4R genotype did not modify the effects of fat or carbohydrate intakes on appetite measures. Similar interaction patterns were observed in whites. Conclusion: Our data suggest that individuals with the MC4R rs7227255 A allele rather than the non-A allele might experience greater increases in appetite and food craving when consuming a high-protein weight-loss diet. This trial was registered at clinicaltrials.gov as NCT00072995. © 2017 American Society for Nutrition.

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