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Search Results: 1 - 10 of 13078 matches for " Ted Christopher "
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The Heritability Challenge to Evolution and Materialism: An Opening for Religious Perspectives  [PDF]
Ted Christopher
Open Journal of Philosophy (OJPP) , 2018, DOI: 10.4236/ojpp.2018.84025
Abstract: There are under-appreciated, serious behavioral challenges to science’s understanding of life and its evolution. The general challenge to that understanding, though, has unfolded in the form of pervasive failures in the search for the DNA origins of many heritable characteristics. Science has placed enormous faith in the presumed workings of DNA, including of course as a foundation for evolution. The stunning inability to identify the DNA bases for many heritable characteristics amongst humans—sometimes termed the missing heritability problem—is a big challenge to the largely unquestioned, biological vision. This situation is discussed herein along with its possible implications for religious perspectives.
Oligopsony, Information Technology, and Systems Integration: The Case of the Healthcare Supply Industry
Christopher Brown,Ted Lee
International Journal of Business and Management , 2009,
Abstract: This article examines the importance of oligopsony power in stimulating the diffusion of cost saving information technology throughout the healthcare supply chain. We present evidence to support the hypothesis that the optimal structure of the distribution stage of healthcare supply industry is (from the standpoint of cost minimization and reliability) highly concentrated. The hypothesis is predicated on two factors: (1) host-integrated electronic data interchange (EDI) is subject to substantial economies of scale; and (2) the oligopsony power possessed by giant distributors can be leveraged to force upstream suppliers into compliance with technical standards for EDI and automated data capture.
Static post-Newtonian equivalence of GR and gravity with a dynamical preferred frame
Christopher Eling,Ted Jacobson
Physics , 2003, DOI: 10.1103/PhysRevD.69.064005
Abstract: A generally covariant extension of general relativity (GR) in which a dynamical unit timelike vector field is coupled to the metric is studied in the asymptotic weak field limit of spherically symmetric static solutions. The two post-Newtonian parameters known as the Eddington-Robertson-Schiff parameters are found to be identical to those in the case of pure GR, except for some non-generic values of the coefficients in the Lagrangian.
Black Holes in Einstein-Aether Theory
Christopher Eling,Ted Jacobson
Physics , 2006, DOI: 10.1088/0264-9381/27/4/049802
Abstract: We study black hole solutions in general relativity coupled to a unit timelike vector field dubbed the "aether". To be causally isolated a black hole interior must trap matter fields as well as all aether and metric modes. The theory possesses spin-0, spin-1, and spin-2 modes whose speeds depend on four coupling coefficients. We find that the full three-parameter family of local spherically symmetric static solutions is always regular at a metric horizon, but only a two-parameter subset is regular at a spin-0 horizon. Asymptotic flatness imposes another condition, leaving a one-parameter family of regular black holes. These solutions are compared to the Schwarzschild solution using numerical integration for a special class of coupling coefficients. They are very close to Schwarzschild outside the horizon for a wide range of couplings, and have a spacelike singularity inside, but differ inside quantitatively. Some quantities constructed from the metric and aether oscillate in the interior as the singularity is approached. The aether is at rest at spatial infinity and flows into the black hole, but differs significantly from the the 4-velocity of freely-falling geodesics.
Two-dimensional gravity with a dynamical aether
Christopher Eling,Ted Jacobson
Physics , 2006, DOI: 10.1103/PhysRevD.74.084027
Abstract: We investigate the two-dimensional behavior of gravity coupled to a dynamical unit timelike vector field, i.e. "Einstein-aether theory". The classical solutions of this theory in two dimensions depend on one coupling constant. When this coupling is positive the only solutions are (i) flat spacetime with constant aether, (ii) de Sitter or anti-de Sitter spacetimes with a uniformly accelerated unit vector invariant under a two-dimensional subgroup of SO(2,1) generated by a boost and a null rotation, and (iii) a non-constant curvature spacetime that has no Killing symmetries and contains singularities. In this case the sign of the curvature is determined by whether the coupling is less or greater than one. When instead the coupling is negative only solutions (i) and (iii) are present. This classical study of the behavior of Einstein-aether theory in 1+1 dimensions may provide a starting point for further investigations into semiclassical and fully quantum toy models of quantum gravity with a dynamical preferred frame.
Spherical Solutions in Einstein-Aether Theory: Static Aether and Stars
Christopher Eling,Ted Jacobson
Physics , 2006, DOI: 10.1088/0264-9381/27/4/049801
Abstract: The time independent spherically symmetric solutions of General Relativity (GR) coupled to a dynamical unit timelike vector are studied. We find there is a three-parameter family of solutions with this symmetry. Imposing asymptotic flatness restricts to two parameters, and requiring that the aether be aligned with the timelike Killing field further restricts to one parameter, the total mass. These "static aether" solutions are given analytically up to solution of a transcendental equation. The positive mass solutions have spatial geometry with a minimal area 2-sphere, inside of which the area diverges at a curvature singularity occurring at an extremal Killing horizon that lies at a finite affine parameter along a radial null geodesic. Regular perfect fluid star solutions are shown to exist with static aether exteriors, and the range of stability for constant density stars is identified.
Neutron stars in Einstein-aether theory
Christopher Eling,Ted Jacobson,M. Coleman Miller
Physics , 2007, DOI: 10.1103/PhysRevD.80.129906
Abstract: As current and future experiments probe strong gravitational regimes around neutron stars and black holes, it is desirable to have theoretically sound alternatives to general relativity against which to test observations. Here we study the consequences of one such generalization, Einstein-aether theory, for the properties of non-rotating neutron stars. This theory has a parameter range that satisfies all current weak-field tests. We find that within this range it leads to lower maximum neutron star masses, as well as larger surface redshifts at a particular mass, for a given nuclear equation of state. For non-rotating black holes and neutron stars, the innermost stable circular orbit is only slightly modified in this theory.
Non-equilibrium Thermodynamics of Spacetime
Christopher Eling,Raf Guedens,Ted Jacobson
Physics , 2006, DOI: 10.1103/PhysRevLett.96.121301
Abstract: It has previously been shown that the Einstein equation can be derived from the requirement that the Clausius relation dS = dQ/T hold for all local acceleration horizons through each spacetime point, where dS is one quarter the horizon area change in Planck units, and dQ and T are the energy flux across the horizon and Unruh temperature seen by an accelerating observer just inside the horizon. Here we show that a curvature correction to the entropy that is polynomial in the Ricci scalar requires a non-equilibrium treatment. The corresponding field equation is derived from the entropy balance relation dS =dQ/T+dS_i, where dS_i is a bulk viscosity entropy production term that we determine by imposing energy-momentum conservation. Entropy production can also be included in pure Einstein theory by allowing for shear viscosity of the horizon.
Numerical simulations of gravitational collapse in Einstein-aether theory
David Garfinkle,Christopher Eling,Ted Jacobson
Physics , 2007, DOI: 10.1103/PhysRevD.76.024003
Abstract: We study gravitational collapse of a spherically symmetric scalar field in Einstein-aether theory (general relativity coupled to a dynamical unit timelike vector field). The initial value formulation is developed, and numerical simulations are performed. The collapse produces regular, stationary black holes, as long as the aether coupling constants are not too large. For larger couplings a finite area singularity occurs. These results are shown to be consistent with the stationary solutions found previously.
Minocycline and doxycycline therapy in community patients with rheumatoid arthritis: prescribing patterns, patient-level determinants of use, and patient-reported side effects
Christopher J Smith, Harlan Sayles, Ted R Mikuls, Kaleb Michaud
Arthritis Research & Therapy , 2011, DOI: 10.1186/ar3491
Abstract: We studied 15,716 patients with RA observed between 1998 and 2009 while participating in a long-term US observational study.Minocycline or doxycycline was prescribed by 18% of rheumatologists (interquartile range one to two patients per physician) to 9% of RA patients. Significant differences between minocycline-treated and doxycycline-treated patients and nontreated patients included age (58.4 years vs. 59.8 years), RA duration (14.8 years vs. 13.7 years), Caucasian race (93.7% vs. 89.7%), lifetime DMARDs and biologics (3.3 vs. 2.5), prednisone use (40.1% vs. 35.3%), and Medical Outcomes Study 36-Item Short Form Survey physical component summary score (35.0 vs. 36.4). In multivariable Cox regression, patients initiating minocycline or doxycycline had increased disease activity, more comorbidities, and a greater number of prior nonbiologic DMARDs. Side effects were reported by 17.8% of minocycline users and 11.8% of doxycycline users. Skin complaints accounted for 54% of minocycline patient-reported side effects. The most commonly effected organ systems for doxycycline were gastrointestinal (35.4%) and skin (33.7%). Approximately 75% of side effects were of mild or moderate severity.Rheumatologists have not embraced minocycline or doxycycline as primary treatment options for RA and reserve their use primarily in patients with long-standing, refractory disease. These drugs are generally well tolerated, with skin complaints, nausea, and dizziness being the most common patient-reported side effects.Minocycline and doxycycline are semi-synthetic tetracycline antibiotics with anti-inflammatory properties that are used to treat multiple inflammatory diseases, including rheumatoid arthritis (RA) [1,2]. Tetracyclines exhibit multiple anti-inflammatory properties, including the inhibition of T-cell activation and chemotaxis, the downregulation of proinflammatory cytokines, including TNFα and IL-1β [1-3], and the inhibition of matrix metalloproteinases [4-6].Minocycline has p
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