749 research outputs found
Testing Cosmological General Relativity against high redshift observations
Several key relations are derived for Cosmological General Relativity which
are used in standard observational cosmology. These include the luminosity
distance, angular size, surface brightness and matter density. These relations
are used to fit type Ia supernova (SNe Ia) data, giving consistent, well
behaved fits over a broad range of redshift . The best fit to the
data for the local density parameter is .
Because is within the baryonic budget there is no need for any
dark matter to account for the SNe Ia redshift luminosity data. From this local
density it is determined that the redshift where the universe expansion
transitions from deceleration to acceleration is . Because the fitted data covers the range of the
predicted transition redshift , there is no need for any dark energy to
account for the expansion rate transition. We conclude that the expansion is
now accelerating and that the transition from a closed to an open universe
occurred about ago.Comment: Rewritten, improved and revised the discussion. This is now a
combined paper of the former version and the Addendu
Customers driving a firm's responsible innovation response for grand challenges : A co-active issue-selling perspective
Grand challenges vary across industries and call for firms to craft a responsible innovation response to effectively address them. However, key questions concerning why firms embrace responsible innovation and the process by which they respond to grand challenges have yet to be fully answered. We integrate an issue-selling theoretical lens and the customer role from an innovation perspective to theorize about the different influencing motives that customers exert on their corresponding supplying firm to craft a more responsible innovation response to grand challenges. Based on qualitative data collected in almost a 10-year period from multiple respondents across eight customer firms and two supplying firms, we identify three core motives—regulatory, business opportunity, and socio-environmental motives—that propel customers to influence supplying firms to craft different forms of responsible innovation responses. Our research also reveals three vital socio-human capital pathways—human capital, socio-behavioral, and relationship—which, in turn, foster a co-active engagement in addressing grand challenges innovatively and responsibly. In so doing, this research advances novel theorizing on co-active engagement in responsible innovation where the customer acts as the primary champion and the supplier as the implementer. We discuss the important implications for customers and other stakeholders.© 2023 The Authors. Journal of Product Innovation Management published by Wiley Periodicals LLC on behalf of Product Development & Management Association. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.fi=vertaisarvioitu|en=peerReviewed
Tetrads in SU(3) X SU(2) X U(1) Yang-Mills geometrodynamics
The relationship between gauge and gravity amounts to understanding
underlying new geometrical local structures. These structures are new tetrads
specially devised for Yang-Mills theories, Abelian and Non-Abelian in
four-dimensional Lorentzian spacetimes. In the present manuscript a new tetrad
is introduced for the Yang-Mills SU(3) X SU(2) X U(1) formulation. These new
tetrads establish a link between local groups of gauge transformations and
local groups of spacetime transformations. New theorems are proved regarding
isomorphisms between local internal SU(3) X SU(2) X U(1) groups and local
tensor products of spacetime LB1 and LB2 groups of transformations. The new
tetrads and the stress-energy tensor allow for the introduction of three new
local gauge invariant objects. Using these new gauge invariant objects and in
addition a new general local duality transformation, a new algorithm for the
gauge invariant diagonalization of the Yang-Mills stress-energy tensor is
developed.Comment: There is a new appendix. The unitary transformations by local SU(2)
subgroup elements of a local group coset representative is proved to be a new
local group coset representative. This proof is relevant to the study of the
memory of the local tetrad SU(3) generated gauge transformations. Therefore,
it is also relevant to the group theorems proved in the paper. arXiv admin
note: substantial text overlap with arXiv:gr-qc/060204
Spiral galaxy rotation curves determined from Carmelian general relativity
Equations of motion, in cylindrical co-ordinates, for the observed rotation
of gases within the gravitational potential of spiral galaxies have been
derived from Carmeli's Cosmological General Relativity theory. A Tully-Fisher
type relation results and rotation curves are reproduced without the need for
non-baryonic halo dark matter. Two acceleration regimes are discovered that are
separated by a critical accleration .
For accelerations larger than the critical value the Newtonian force law
applies, but for accelerations less than the critical value the Carmelian
regime applies. In the Newtonian regime the accelerations fall off as ,
but in the Carmelian regime the accelerations fall off as . This is new
physics but is exactly what is suggested by Migrom's phenomenological MOND
theory.Comment: 9 pages, 10 figures, Int. J. Theor. Phys, corrected typo
Far-field e-beam detection of hybrid cavity-plasmonic modes in gold micro-holes
Manipulation of light-beams with subwavelenth metallic devices has motivated
intensive studies, following the discovery of extraordinary transmission of
electromagnetic waves through sub-wavelength apertures in thin noble-metal
films. The propagation of light in these holes can be investigated at greately
improved spatial resolution by means of focused electron-beams. Here we
demonstrate direct e-beam excitation of radiative cavity modes well below the
surface plasmon (SP) frequency, of isolated rectangular holes in gold films,
illuminating the hotly debated phenomenon of the extraordinary optical
transmission through subwavelength holes. The exceptionally long range e-beam
interaction with the metal through the vacuum, involving electromagnetic
excitations within the light cone, is allowed by momentum conservation
breakdown along the e-beam axis. Two types of lowlying excited modes are
revealed: radiative cavity modes which are nearly unaffected by SPs, and SP
polariton modes with waveguide character in the near field region of the slit
walls, which in spite of the strong hybridization preserve the waveguide cutoff
frequencies and symmetry characteristics.Comment: 16 pages, 4 figures, 1 tabl
General covariance violation and the gravitational dark matter. I. Scalar graviton
The violation of the general covariance is proposed as a resource of the
gravitational dark matter. The minimal violation of the covariance to the
unimodular one is associated with the massive scalar graviton as the simplest
representative of such a matter. The Lagrangian formalism for the continuous
medium, the perfect fluid in particular, in the scalar graviton environment is
developed. The implications for cosmology are shortly indicated.Comment: 11 pages; minor correction
Ceftazidime-avibactam or best available therapy in patients with ceftazidime-resistant Enterobacteriaceae and Pseudomonas aeruginosa complicated urinary tract infections or complicated intra-abdominal infections (REPRISE): a randomised, pathogen-directed, phase 3 study
Background
Carbapenems are frequently the last line of defence in serious infections due to multidrug-resistant Gram-negative bacteria, but their use is threatened by the growing prevalence of carbapenemase-producing pathogens. Ceftazidime-avibactam is a potential new agent for use in such infections. We aimed to assess the efficacy, safety, and tolerability of ceftazidime-avibactam compared with best available therapy in patients with complicated urinary tract infection or complicated intra-abdominal infection due to ceftazidime-resistant Gram-negative pathogens.
Methods
REPRISE was a pathogen-directed, international, randomised, open-label, phase 3 trial that recruited patients from hospitals across 16 countries worldwide. Eligible patients were aged 18–90 years with complicated urinary tract infection or complicated intra-abdominal infection caused by ceftazidime-resistant Enterobacteriaceae or Pseudomonas aeruginosa. Patients were randomised (1:1) to 5–21 days of treatment with either ceftazidime-avibactam (a combination of 2000 mg ceftazidime plus 500 mg avibactam, administered via a 2-h intravenous infusion every 8 h) or best available therapy. The primary endpoint was clinical response at the test-of-cure visit, 7–10 days after last infusion of study therapy, analysed in all patients who had at least one ceftazidime-resistant Gram-negative pathogen, as confirmed by the central laboratory, and who received at least one dose of study drug. Safety endpoints were assessed in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT01644643.
Findings
Between Jan 7, 2013, and Aug 29, 2014, 333 patients were randomly assigned, 165 to ceftazidime-avibactam and 168 to best available therapy. Of these, 154 assigned to ceftazidime-avibactam (144 with complicated urinary tract infection and ten with complicated intra-abdominal infection) and 148 assigned to best available therapy (137 with complicated urinary tract infection and 11 with complicated intra-abdominal infection) were analysed for the primary outcome. 163 (97%) of 168 patients in the best available therapy group received a carbapenem, 161 (96%) as monotherapy. The overall proportions of patients with a clinical cure at the test-of-cure visit were similar with ceftazidime-avibactam (140 [91%; 95% CI 85·6–94·7] of 154 patients) and best available therapy (135 [91%; 85·9–95·0] of 148 patients). 51 (31%) of 164 patients in the ceftazidime-avibactam group and 66 (39%) of 168 in the best available therapy group had an adverse event, most of which were mild or moderate in intensity. Gastrointestinal disorders were the most frequently reported treatment-emergent adverse events with both ceftazidime-avibactam (21 [13%] of 164 patients) and best available therapy (30 [18%] of 168 patients). No new safety concerns were identified for ceftazidime-avibactam.
Interpretation
These results provide evidence of the efficacy of ceftazidime-avibactam as a potential alternative to carbapenems in patients with ceftazidime-resistant Enterobacteriaceae and P aeruginosa.
Funding
AstraZeneca
The most general axially symmetric electrovac spacetime adimitting separable equations of motion
We obtain the most general solution of the Einstein electro - vacuum equation
for the stationary axially symmetric spacetime in which the Hamilton-Jacobi and
Klein - Gordon equations are separable. The most remarkable feature of the
solution is its invariance under the duality transformation involving mass and
NUT parameter, and the radial and angle coordinates. It is the general solution
for a rotating (gravitational dyon) particle which is endowed with both
gravoelectric and gravomagnetic charges, and there exists a duality
transformation from one to the other. It also happens to be a transform of the
Kerr - NUT solution. Like the Kerr family, it is also possible to make this
solution radiating which asymptotically conforms to the Vaidya null radiation.Comment: 9 pages, RevTex, Accepted by Class. Quantum Grav. Title, Abstract and
some expressions have been modified, typos corrected. The solution and main
result remain unaltere
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