1,292 research outputs found
Description of Friedmann Observables in Quantum Universe
The solution of the problem of describing the Friedmann observables (the
Hubble law, the red shift, etc.) in quantum cosmology is proposed on the basis
of the method of gaugeless Hamiltonian reduction in which the gravitational
part of the energy constraint is considered as a new momentum. We show that the
conjugate variable corresponding to the new momentum plays a role of the
invariant time parameter of evolution of dynamical variables in the sector of
the Dirac observables of the general Hamiltonian approach. Relations between
these Dirac observables and the Friedmann observables of the expanding Universe
are established for the standard Friedmann cosmological model with dust and
radiation. The presented reduction removes an infinite factor from the
functional integral, provides the normalizability of the wave function of the
Universe and distinguishes the conformal frame of reference where the Hubble
law is caused by the alteration of the conformal dust mass.Comment: 10 pages, LaTe
A fully coupled 3D transport model in SPH for multi-species reaction-diffusion systems
In this paper we present a fully generalized transport model for multiple species in complex two and three-dimensional geometries. Based on previous work [1] we have extended our interfacial reaction-diffusion model to handle arbitrary numbers of species allowing for coupled reaction models. Each species is tracked independently and we consider different physics of a species with respect to the bulk phases in contact. We
use our SPH model to simulate the reaction-diffusion problem on a pore-scale level of a solid oxide fuel cell (SOFC) with special emphasize on the effect of surface diffusion
Cameos of compassion: exploring compassionate care using secondary analysis of digital patients’ stories.
Patient stories have been identified as a powerful tool to improve quality of care. Healthtalk.org is a digital resource (specific health-related website) presenting patients’ experiences of illness and healthcare through trigger films, videos and articles. Data have been generated from narrative interviews conducted by experienced researchers, based at the Health Experiences Research Group (HERG), University of Oxford. Our project explored the potential use of secondary analysis of digital sources as a methodological innovation to develop as a tool for teaching compassion to nursing students. For that, a purposive sample of transcripts from the HERG archive were selected for secondary analysis. Patients expressed both positive and negative experiences of care. Positive themes included: continuity of care and attentiveness to the fundamentals of care. Negative themes were related to poor quality of care; ignoring patient and family needs; and not being available for patients and family when needed. We concluded that secondary analysis of narrative interviews provides a powerful resource for identifying positive and negative patient experiences for learning and teaching. These can be designed into a digital toolkit and used as a learning and teaching resource to develop staff and students’ reflexivity in relation to the values and leadership behaviours associated with compassionate care and positive practice
Visual Interest Prediction with Attentive Multi-Task Transfer Learning
Visual interest & affect prediction is a very interesting area of research in
the area of computer vision. In this paper, we propose a transfer learning and
attention mechanism based neural network model to predict visual interest &
affective dimensions in digital photos. Learning the multi-dimensional affects
is addressed through a multi-task learning framework. With various experiments
we show the effectiveness of the proposed approach. Evaluation of our model on
the benchmark dataset shows large improvement over current state-of-the-art
systems
Towards a formalism for mapping the spacetimes of massive compact objects: Bumpy black holes and their orbits
Observations have established that extremely compact, massive objects are
common in the universe. It is generally accepted that these objects are black
holes. As observations improve, it becomes possible to test this hypothesis in
ever greater detail. In particular, it is or will be possible to measure the
properties of orbits deep in the strong field of a black hole candidate (using
x-ray timing or with gravitational-waves) and to test whether they have the
characteristics of black hole orbits in general relativity. Such measurements
can be used to map the spacetime of a massive compact object, testing whether
the object's multipoles satisfy the strict constraints of the black hole
hypothesis. Such a test requires that we compare against objects with the
``wrong'' multipole structure. In this paper, we present tools for constructing
bumpy black holes: objects that are almost black holes, but that have some
multipoles with the wrong value. The spacetimes which we present are good deep
into the strong field of the object -- we do not use a large r expansion,
except to make contact with weak field intuition. Also, our spacetimes reduce
to the black hole spacetimes of general relativity when the ``bumpiness'' is
set to zero. We propose bumpy black holes as the foundation for a null
experiment: if black hole candidates are the black holes of general relativity,
their bumpiness should be zero. By comparing orbits in a bumpy spacetime with
those of an astrophysical source, observations should be able to test this
hypothesis, stringently testing whether they are the black holes of general
relativity. (Abridged)Comment: 16 pages + 2 appendices + 3 figures. Submitted to PR
Despite NAIS concerns electronic identification use by cow-calf producers is increasing
The proposed U.S. National Animal Identification System has generated concerns
among producers relative to implementation
of the system. Many of these concerns stem
from the USDA’s Bovine Identification Working
Group’s recommendations to use electronic
Identification Plan Bovine Working Group has recommended radio frequency identification as the technology to individually identify cattle. Understanding and implementing an electronic identification system for cow-calf producers
is believed to be one of the greatest
challenges of implementing the National
Animal Identification System
Ovarian structures and uterine environment are associated with phenotypic and genetic merit for performance in lactating dairy cows
peer-reviewedThe objective of this study was to estimate the association between detailed reproductive phenotypes for cows categorized as divergent for phenotypic and genetic performance. The hypothesis was that higher yielding animals, either phenotypically or genetically, would have compromised ovarian and uterine reproductive performance. Detailed reproductive traits including multiple ovulations, cystic ovarian structures, corpus luteum (CL) presence, and uterine environment were available on 9675 ultrasound records from 8174 dairy lactating cows, calved between 10 and 70 days. Cows were categorized, within parity, into low, average, or high for each of the performance traits. There was a greater likelihood of multiple ovulations in cows with greater phenotypic yields (odds ratio: 1.53–1.81) and greater genetic merit for yield (odds ratio: 1.31–1.59) relative to lower performing contemporaries. After adjustment for genetic merit, a similar trend of increased odds (odds ratio: 1.29–1.87) of multiple ovulations in higher yielding cows was observed compared with the lowest yielding category. There was no association between either phenotypic milk composition or genetic merit for milk composition with the likelihood of multiple ovulations. The likelihood of cystic ovarian structures was highest in cows with greatest phenotypic milk yields (odds ratio: 2.75–3.24), greater genetic merit for milk yield (odds ratio: 1.30–1.51), and even after adjustment for genetic merit there was a greater likelihood of cystic ovarian structures in cows with the highest milk yields (odds ratio: 2.71–2.95), compared with cows in the lowest category for each of the milk traits. Cows with average phenotypic milk yields were more likely to have a CL, compared with the lowest yielding category (odds ratio: 1.20–1.23), and these associations remained after adjustment for genetic merit of the trait. The likelihood of CL presence was highest in cows with the lowest genetic merit for milk. Lower fat:protein ratio was associated with an increased likelihood of CL presence compared with cows with greater fat:protein ratio and cows with the highest phenotypic milk composition were more likely to have a CL compared with cows in the lowest composition category. Genetic predisposition to higher somatic cell score was associated with a reduced risk of multiple ovulations (odds ratio: 0.69; 95% CI: 0.55–0.87) but an increased likelihood of CL presence (odds ratio: 2.66; 95% CI: 2.09–3.37) and poorer uterine health score (odds ratio: 1.36; 95% CI: 1.20–1.55). There was a lower likelihood of multiple ovulations, cystic ovarian structures, and poorer uterine health and an increased likelihood of CL presence in cows with superior genetic merit for reproductive performance and survival
Elementary Professional Development within a ‘Practical’ Action Research Effort to Improve Student Literacy
The purpose of this inquiry was to support and augment the action research efforts of elementary teachers who were attempting to enhance literacy outcomes in their respective classrooms. Included are elementary teacher insights, university-based facilitator views, and principal perspectives that together complete a picture of our professional development efforts. Together the data provide an overview of an action research effort, wherein praxis was noted as a necessary element to assume ‘practical’ investigative roles. Praxis herein is the deliberate, informed, planned, and systematic action which is the critical underpinning of all action research efforts. The action in this case was directed towards improvement and implementation of an instructional initiative. This outcome brings with it an immense level of significance in that all educators seek to improve educational outcomes personally, professionally, and politically; therefore a report such as this may be viewed as an essential tool to refine educational practice
Health-Related Quality of Life and All-Cause Mortality among Older Healthy Individuals in Australia and the United States:A Prospective Cohort Study
Published online: 3 January 2021PURPOSE: Previous research has demonstrated that lower health-related quality of life (HRQoL) is associated with higher morbidity and mortality, especially in-patient groups. The association of HRQoL with all-cause mortality in community samples requires further investigation. This study aimed to examine whether HRQoL predicts all-cause mortality in older healthy community-dwelling people from Australia and the United States (U.S.) enrolled in the Aspirin in Reducing Events in the Elderly (ASPREE) trial. We also explored whether this association varies by gender or country. METHOD: A prospective cohort of 19,106 individuals aged 65-98 years, who were without a dementia diagnosis or a known major life-limiting disease, and completed the 12-item short-form-HRQoL at recruitment (2010-2014). They were followed until June 2017. Cox proportional-hazard models were used to determine the association between the physical (PCS) and mental component scores (MCS) of HRQoL and all-cause mortality, adjusting for sociodemographic factors, health-related behaviours and clinical measures. Hazards ratios were estimated for every 10-unit increase in PCS or MCS. RESULTS: There were 1052 deaths over a median 4.7-years (interquartile range 3.6-5.7) of follow-up, with 11.9 events per 1000 person-years. Higher PCS was associated with lower all-cause mortality (HR 0.83, 95% CI 0.77, 0.89) in the entire sample, while higher MCS was associated with lower mortality among U.S. participants only (HR 0.78, 95% CI 0.63, 0.95). Gender differences in the association of either PCS or MCS with mortality were not observed. CONCLUSION: Our large study provides evidence that HRQoL is inversely associated with all-cause mortality among initially healthy older people.Aung Zaw Zaw Phyo, Joanne Ryan, David A. Gonzalez-Chica, Robyn L. Woods, Christopher M. Reid, Mark R. Nelson ... et al
Did Galaxy Assembly and Supermassive Black-Hole Growth go hand-in-hand?
In this paper, we address whether the growth of supermassive black-holes has
kept pace with the process of galaxy assembly. For this purpose, we first
searched the Hubble Ultra Deep Field (HUDF) for "tadpole galaxies", which have
a knot at one end and an extended tail. They appear dynamically unrelaxed --
presumably early-stage mergers -- and make up ~6% of the field galaxy
population. Their redshift distribution follows that of field galaxies,
indicating that -- if tadpole galaxies are indeed dynamically young -- the
process of galaxy assembly generally kept up with the reservoir of field
galaxies as a function of epoch. Next, we present a search for HUDF objects
with point-source components that are optically variable (at the >~3.0 sigma
level) on timescales of weeks--months. Among 4644 objects to i_AB=28.0 mag (10
sigma), 45 have variable point-like components, which are likely weak AGN.
About 1% of all field objects show variability for 0.1 < z < 4.5, and their
redshift distribution is similar to that of field galaxies. Hence supermassive
black-hole growth in weak AGN likely also kept up with the process of galaxy
assembly. However, the faint AGN sample has almost no overlap with the tadpole
sample, which was predicted by recent hydrodynamical numerical simulations.
This suggests that tadpole galaxies are early-stage mergers, which likely
preceded the ``turn-on'' of the AGN component and the onset of visible
point-source variability by >~1 Gyr.Comment: 9 pages, Latex2e requires 'elsart' and 'elsart3' (included), 10
postscript figures. To appear in the Proceedings of the Leiden Workshop on
"QSO Host Galaxies: Evolution and Environment", eds. P.D. Barthel & D.B.
Sanders (New Astron. Rev., 2006
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