347 research outputs found
Founding quantum theory on the basis of consciousness
In the present work, quantum theory is founded on the framework of
consciousness, in contrast to earlier suggestions that consciousness might be
understood starting from quantum theory. The notion of streams of
consciousness, usually restricted to conscious beings, is extended to the
notion of a Universal/Global stream of conscious flow of ordered events. The
streams of conscious events which we experience constitute sub-streams of the
Universal stream. Our postulated ontological character of consciousness also
consists of an operator which acts on a state of potential consciousness to
create or modify the likelihoods for later events to occur and become part of
the Universal conscious flow. A generalized process of measurement-perception
is introduced, where the operation of consciousness brings into existence, from
a state of potentiality, the event in consciousness. This is mathematically
represented by (a) an operator acting on the state of potential-consciousness
before an actual event arises in consciousness and (b) the reflecting of the
result of this operation back onto the state of potential-consciousness for
comparison in order for the event to arise in consciousness. Beginning from our
postulated ontology that consciousness is primary and from the most elementary
conscious contents, such as perception of periodic change and motion, quantum
theory follows naturally as the description of the conscious experience.Comment: 41 pages, 3 figures. To be published in Foundations of Physics, Vol
36 (6) (June 2006), published online at
http://dx.doi.org/10.1007/s10701-006-9049-
The Possibilist Transactional Interpretation and Relativity
A recent ontological variant of Cramer's Transactional Interpretation, called
"Possibilist Transactional Interpretation" or PTI, is extended to the
relativistic domain. The present interpretation clarifies the concept of
'absorption,' which plays a crucial role in TI (and in PTI). In particular, in
the relativistic domain, coupling amplitudes between fields are interpreted as
amplitudes for the generation of confirmation waves (CW) by a potential
absorber in response to offer waves (OW), whereas in the nonrelativistic
context CW are taken as generated with certainty. It is pointed out that
solving the measurement problem requires venturing into the relativistic domain
in which emissions and absorptions take place; nonrelativistic quantum
mechanics only applies to quanta considered as 'already in existence' (i.e.,
'free quanta'), and therefore cannot fully account for the phenomenon of
measurement, in which quanta are tied to sources and sinks.Comment: Final version with some minor corrections as published in Foundations
of Physics. This paper has significant overlap with Chapter 6 of my book on
the Transactional Interpretation, forthcoming from Cambridge University
Press:
http://www.cambridge.org/us/knowledge/isbn/item6860644/?site_locale=en_US
(Additional preview material is available at rekastner.wordpress.com)
Comments welcom
SN 2005cg: Explosion physics and circumstellar interaction of a normal type la supernova in a low-luminosity host
We present the spectral evolution, light curve, and corresponding interpretation for the "normal-bright" Type la supernova 2005cg discovered by ROTSE-IIIc. The host is a low-luminosity (Mr = -16.75) blue galaxy with strong indications of active star formation and an environment similar to that expected for SNe la at high redshifts. Earlytime (t ̃ -10 days) optical spectra obtained with the HET reveal an asymmetric, triangular-shaped Si II absorption feature at about 6100 Å with a sharp transition to the continuum at a blueshift of about 24,000 km s-1. By 4 days before maximum, the Si n absorption feature becomes symmetric with smoothly curved sides. Similar Si n profile evolution has previously been observed in other supemovae and is predicted by some explosion models, but its significance has not been fully recognized. Although the spectra predicted by pure deflagration and delayed detonation models are similar near maximum light, they predict qualitatively different chemical abundances in the outer layers and thus give qualitatively different spectra at the earliest phases. The Si line observed in SN 2005cg at early times requires the presence of burning products at high velocities, and the triangular shape is likely to be formed in an extended region of slowly declining Si abundance that characterizes delayed detonation models. The spectra show a high-velocity Ca n IR feature that coincides in velocity space with the Si n cutoff. This supports the interpretation that the Ca n is formed when the outer layers of the SN ejecta sweep up about 5 × 10-3 M, of material within the progenitor system. We compare our results with other "Branch-normal" SNe la with early-time spectra, namely, SN 2003du, 1999ee, and 1994D. Although the expansion velocities based on their Si n absorption minima differ, all show triangular-shaped profiles and velocity cutoffs between 23,000 and 25,000 km s-1, which are consistent with the Doppler shifts of their respective high-velocity Ca II IR features. SN 1990N-like objects, however, showed distinctly different behavior, which may suggest separate progenitor subclasses
Development and validation of a 5-year mortality prediction model using regularized regression and Medicare data
Purpose: De-implementation of low-value services among patients with limited life expectancy is challenging. Robust mortality prediction models using routinely collected health care data can enhance health care stakeholders' ability to identify populations with limited life expectancy. We developed and validated a claims-based prediction model for 5-year mortality using regularized regression methods. Methods: Medicare beneficiaries age 66 or older with an office visit and at least 12 months of pre-visit continuous Medicare A/B enrollment were identified in 2008. Five-year mortality was assessed through 2013. Secondary outcomes included 30-, 90-, and 180-day and 1-year mortality. Claims-based predictors, including comorbidities and indicators of disability, frailty, and functional impairment, were selected using regularized logistic regression, applying the least absolute shrinkage and selection operator (LASSO) in a random 80% training sample. Model performance was assessed and compared with the Gagne comorbidity score in the 20% validation sample. Results: Overall, 183 204 (24%) individuals died. In addition to demographics, 161 indicators of comorbidity and function were included in the final model. In the validation sample, the c-statistic was 0.825 (0.823-0.828). Median-predicted probability of 5-year mortality was 14%; almost 4% of the cohort had a predicted probability greater than 80%. Compared with the Gagne score, the LASSO model led to improved 5-year mortality classification (net reclassification index = 9.9%; integrated discrimination index = 5.2%). Conclusions: Our claims-based model predicting 5-year mortality showed excellent discrimination and calibration, similar to the Gagne score model, but resulted in improved mortality classification. Regularized regression is a feasible approach for developing prediction tools that could enhance health care research and evaluation of care quality
Cardiovascular genetic risk testing for targeting statin therapy in the primary prevention of atherosclerotic cardiovascular disease
Background: It is unclear whether testing for novel risk factors, such as a cardiovascular genetic risk score (cGRS), improves clinical decision making or health outcomes when used for targeting statin initiation in the primary prevention of atherosclerotic cardiovascular disease (ASCVD). Our objective was to estimate the cost-effectiveness of cGRS testing to inform clinical decision making about statin initiation in individuals with low-to-intermediate (2.5%-7.5%) 10-year predicted risk of ASCVD. Methods and Results: We evaluated the cost-effectiveness of testing for a 27-single-nucleotide polymorphism cGRS comparing 4 test/treat strategies: Treat all, treat none, test/treat if cGRS is high, and test/treat if cGRS is intermediate or high. We tested a set of clinical scenarios of men and women, aged 45 to 65 years, with 10-year ASCVD risks between 2.5% and 7.5%. Our primary outcome measure was cost per quality-adjusted life-year gained. Under base case assumptions for statin disutility and cost, the preferred strategy is to treat all patients with ASCVD risk >2.5% without cGRS testing. For certain clinical scenarios, such as a 57-year-old man with a 10-year ASCVD risk of 7.5%, cGRS testing can be cost-effective under a limited set of assumptions; for example, when statins cost 50 000 per quality-adjusted life-year gained) is to test and treat if cGRS is intermediate or high. Overall, the results were not sensitive to assumptions about statin efficacy and harms. Conclusions: Testing for a 27-single-nucleotide polymorphism cGRS is generally not a cost-effective approach for targeting statin therapy in the primary prevention of ASCVD for low- to intermediate-risk patients
Effects of dietary supplementation of conjugated linoleic acids and their inclusion in semen extenders on bovine sperm quality
Isomers of conjugated linoleic acid (CLA) enhances circulating insulin-like growth factor I
(IGF-I) levels. Furthermore, fertility rate of breeding bulls is positively correlated to seminal plasma
IGF-I concentration. Our objective was to evaluate the effect of dietary CLA supplementation and
inclusion to the semen extender on bovine semen quality and freezability. Fourteen bulls, randomly
assigned to control (CTL) and CLA (50 g/day) groups, were supplemented for 10 weeks. Samples
were collected at Weeks −2 (before supplementation), 0, 4, 6 (during supplementation), 10, and 11
(after supplementation). Blood and seminal plasma were analyzed for IGF-I; the ejaculates were
frozen in the following subgroups: CTL (no addition to semen extender), CLA c9, t11 (50 µM), CLA
c9, t11 (100 µM), CLA t10, c12 (50 µM), CLA t10, c12 (100 µM), and CLA mix (50 µM each of CLA c9,
t11 and CLA t10, c12). Sperm motility, morphology, viability, mitochondrial membrane potential, and
reactive oxidative species were assessed. CLA supplementation decreased ejaculates’ total volume,
increased sperm concentration, beat cross frequency, and decreased oxidative stress; it also increased
plasma and seminal plasma IGF-I levels compared to the CTL. The inclusion of CLA c9, t11 100 µM
and CLA mixture in the extender increased live spermatozoa percentage post-thawing compared
to other groups. Our results show a beneficial effect of CLA supplementation on semen quality;
however, further studies evaluating fertilization rates are necessary to corroborate the results.The National Research Foundation South Africa/ Research and Innovation Support and Advancement and the Research and Technology fund.http://www.mdpi.com/journal/animalspm2021Production Animal Studie
Effects of dietary supplementation of conjugated linoleic acids and their inclusion in semen extenders on bovine sperm quality
Isomers of conjugated linoleic acid (CLA) enhances circulating insulin-like growth factor I
(IGF-I) levels. Furthermore, fertility rate of breeding bulls is positively correlated to seminal plasma
IGF-I concentration. Our objective was to evaluate the effect of dietary CLA supplementation and
inclusion to the semen extender on bovine semen quality and freezability. Fourteen bulls, randomly
assigned to control (CTL) and CLA (50 g/day) groups, were supplemented for 10 weeks. Samples
were collected at Weeks −2 (before supplementation), 0, 4, 6 (during supplementation), 10, and 11
(after supplementation). Blood and seminal plasma were analyzed for IGF-I; the ejaculates were
frozen in the following subgroups: CTL (no addition to semen extender), CLA c9, t11 (50 µM), CLA
c9, t11 (100 µM), CLA t10, c12 (50 µM), CLA t10, c12 (100 µM), and CLA mix (50 µM each of CLA c9,
t11 and CLA t10, c12). Sperm motility, morphology, viability, mitochondrial membrane potential, and
reactive oxidative species were assessed. CLA supplementation decreased ejaculates’ total volume,
increased sperm concentration, beat cross frequency, and decreased oxidative stress; it also increased
plasma and seminal plasma IGF-I levels compared to the CTL. The inclusion of CLA c9, t11 100 µM
and CLA mixture in the extender increased live spermatozoa percentage post-thawing compared
to other groups. Our results show a beneficial effect of CLA supplementation on semen quality;
however, further studies evaluating fertilization rates are necessary to corroborate the results.The National Research Foundation South Africa/ Research and Innovation Support and Advancement and the Research and Technology fund.http://www.mdpi.com/journal/animalspm2021Production Animal Studie
Gravitational radiation from gamma-ray bursts as observational opportunities for LIGO and VIRGO
Gamma-ray bursts are believed to originate in core-collapse of massive stars.
This produces an active nucleus containing a rapidly rotating Kerr black hole
surrounded by a uniformly magnetized torus represented by two counter-oriented
current rings. We quantify black hole spin-interactions with the torus and
charged particles along open magnetic flux-tubes subtended by the event
horizon. A major output of Egw=4e53 erg is radiated in gravitational waves of
frequency fgw=500 Hz by a quadrupole mass-moment in the torus. Consistent with
GRB-SNe, we find (i) Ts=90s (tens of s, Kouveliotou et al. 1993), (ii)
aspherical SNe of kinetic energy Esn=2e51 erg (2e51 erg in SN1998bw, Hoeflich
et al. 1999) and (iii) GRB-energies Egamma=2e50 erg (3e50erg in Frail et al.
2001). GRB-SNe occur perhaps about once a year within D=100Mpc. Correlating
LIGO/Virgo detectors enables searches for nearby events and their spectral
closure density 6e-9 around 250Hz in the stochastic background radiation in
gravitational waves. At current sensitivity, LIGO-Hanford may place an upper
bound around 150MSolar in GRB030329. Detection of Egw thus provides a method
for identifying Kerr black holes by calorimetry.Comment: to appear in PRD, 49
Fabrication of Nickel Nanostructure Arrays Via a Modified Nanosphere Lithography
In this paper, we present a modified nanosphere lithographic scheme that is based on the self-assembly and electroforming techniques. The scheme was demonstrated to fabricate a nickel template of ordered nanobowl arrays together with a nickel nanostructure array-patterned glass substrate. The hemispherical nanobowls exhibit uniform sizes and smooth interior surfaces, and the shallow nanobowls with a flat bottom on the glass substrate are interconnected as a net structure with uniform thickness. A multiphysics model based on the level set method (LSM) was built up to understand this fabricating process by tracking the interface between the growing nickel and the electrolyte. The fabricated nickel nanobowl template can be used as a mold of long lifetime in soft lithography due to the high strength of nickel. The nanostructure–patterned glass substrate can be used in optical and magnetic devices due to their shape effects. This fabrication scheme can also be extended to a wide range of metals and alloys
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