949 research outputs found
E864: Experimental Results on Exotic Nuclei and Rare Probes
Experiment 864 at the BNL-AGS was designed to search for exotic states of
strange quark matter and other rare composite particles. The experiment was
commissioned in 1994 and completed its final run in 1998. Here, we present an
overview of the experimental results for the production of light nuclei up to
A=7, antiprotons and antideuterons, hypernuclei and production limits on new
states of quark matter.Comment: 6 pages, 6 figures, quark matter 1999 conference proceeding
Translating solid state organic synthesis from a mixer mill to a continuous twin screw extruder
YesA study on the translation of a solid-state synthetic reaction from a mechanochemical mixer-mill to a continuous twin-screw extruder is discussed herein. The study highlights some considerations to be made and parameters to be tested in the context of a model fluorination reaction, which is the first organic fluorination to be attempted using extrusion. Upon optimization, which features the first use of grinding auxiliary solids to enable effective synthetic extrusion, the difluorination reaction was successfully translated to the extruder, leading to a 100-fold improvement in Space Time Yield (STY); 29 kg m−3 day−1 in a mixer mill to 3395 kg m−3 day−1 in a twin screw extruder.D. L. B is grateful to the EPSRC for a First Grant (D. L. B. EP/P002951/1), CRD for a studentship award to J. L. H., Queen’s University Belfast for a Visiting Research Fellowship and the School of Chemistry at Cardiff University for generous support. S. L. J. is grateful to EPSRC for support (EP/L019655/1)
The impact of age, gender and severity of overactive bladder wet on quality of life, productivity, treatment patterns and satisfaction
Objective:
The objective of this article is to determine the impact of idiopathic overactive bladder wet (OAB wet) severity, age and gender on health-related quality of life (HRQoL), productivity, treatment patterns and treatment satisfaction.
Materials and methods:
A prospective, cross-sectional online survey of adults in the United Kingdom was performed to screen for self-reported symptoms of OAB wet. Respondents completed the King’s Health Questionnaire or the Incontinence Quality of Life, as well as the Euroqol 5D, and the Work Productivity and Activity Impairment Specific Health Problem questionnaire, and questions pertaining to distress, treatment and treatment satisfaction.
Results:
A total of 249 of 1126 respondents (22.1%) met the criteria for OAB wet. Respondents with moderate/severe OAB wet and all women experienced significantly worse HRQoL and work productivity than those with mild symptoms and all men, respectively. Among all OAB wet responders, 62.7% were receiving treatment for their condition, predominantly pads (40.2%); only 1.6% were receiving specialised treatment. Nearly one-half (44.6%) were somewhat or completely dissatisfied with their current treatment.
Conclusion:
In individuals with OAB wet, severity and gender negatively impact HRQoL and work productivity. A substantial proportion of OAB wet individuals were untreated, and low treatment satisfaction was reported in those receiving treatment. Treatment was generally conservative
Variance of transmitted power in multichannel dissipative ergodic structures invariant under time reversal
We use random matrix theory (RMT) to study the first two moments of the wave
power transmitted in time reversal invariant systems having ergodic motion.
Dissipation is modeled by a number of loss channels of variable coupling
strength. To make a connection with ultrasonic experiments on ergodic
elastodynamic billiards, the channels injecting and collecting the waves are
assumed to be negligibly coupled to the medium, and to contribute essentially
no dissipation. Within the RMT model we calculate the quantities of interest
exactly, employing the supersymmetry technique. This approach is found to be
more accurate than another method based on simplifying naive assumptions for
the statistics of the eigenfrequencies and the eigenfunctions. The results of
the supersymmetric method are confirmed by Monte Carlo numerical simulation and
are used to reveal a possible source of the disagreement between the
predictions of the naive theory and ultrasonic measurements.Comment: 10 pages, 2 figure
Virtual Reality in Palliative Care: A Systematic Review
Background: Virtual reality (VR) using head-mounted displays (HMDs) has demonstrated to be an effective tool for treating various somatic and psychological symptoms. Technological advances and increased affordability of VR technology provide an interesting option for delivering psychological interventions to patients in palliative care. The primary aim of this systematic review was to synthesise the available research on the use of VR for enhancing psychological and somatic outcomes for palliative care patients. Secondary aims included assessing general satisfaction and overall usability. Method: A pre-registered systematic literature search was conducted according to PRISMA guidelines using OVID Emcare, Cochrane Library, Embase, Medline, PsycINFO, and PubMed Care Search: Palliative Care Knowledge Network. Peer-reviewed experimental, quasiexperimental, observational, case, and feasibility studies consisting of single or multiple VR sessions using HMDs that reported psychological and/or somatic outcomes were included. Results: Eight studies published between 2019 and 2021 were included, representing 138 patients. While the reported quantitative psychological and somatic outcomes were ambiguous, the qualitative outcomes were largely positive. Participants were generally satisfied with VR, and most studies reported the VR interventions as usable, feasible, and acceptable. Conclusions: VR shows promise in palliative care and generally addresses a range of symptoms with few adverse effects. Future research should consist of adequately powered RCTs evaluating dosage and focusing on providing meaningful activities to enhance outcomes further.Jessica L. Martin, Dimitrios Saredakis, Amanda D. Hutchinson, Gregory B. Crawford, and Tobias Loetsche
Optical Spectra of SNR Candidates in NGC 300
We present moderate-resolution (<5A) long-slit optical spectra of 51 nebular
objects in the nearby Sculptor Group galaxy NGC 300 obtained with the 2.3 meter
Advanced Technology Telescope at Siding Spring Observatory, Australia. Adopting
the criterion of [SII]/Ha>=0.4 to confirm supernova remnants (SNRs) from
optical spectra, we find that of 28 objects previously proposed as SNRs from
optical observations, 22 meet this criterion with six showing [SII]/Ha of less
than 0.4. Of 27 objects suggested as SNRs from radio data, four are associated
with the 28 previously proposed SNRs. Of these four, three (included in the 22
above) meet the criterion. In all, 22 of the 51 nebular objects meet the
[SII]/Ha criterion as SNRs while the nature of the remaining 29 objects remains
undetermined by these observations.Comment: Accepted for publication in Astrophysics & Space Scienc
Radio-Continuum study of the Nearby Sculptor Group Galaxies. Part 1: NGC 300 at lambda = 20 cm
A series of new radio-continuum (lambda=20 cm) mosaic images focused on the
NGC 300 galactic system were produced using archived observational data from
the VLA and/or ATCA. These new images are both very sensitive (rms=60 microJy)
and feature high angular resolution (<10"). The most prominent new feature is
the galaxy's extended radio-continuum emission, which does not match its
optical appearance. Using these newly created images a number of previously
unidentified discrete sources have been discovered. Furthermore, we demonstrate
that a joint deconvolution approach to imaging this complete data-set is
inferior when compared to an immerge approach.Comment: 13 pages, 12 figures, accepted to APSS, new version to correct the
missing reference
Approach to equilibrium for a class of random quantum models of infinite range
We consider random generalizations of a quantum model of infinite range
introduced by Emch and Radin. The generalization allows a neat extension from
the class of absolutely summable lattice potentials to the optimal class
of square summable potentials first considered by Khanin and Sinai and
generalised by van Enter and van Hemmen. The approach to equilibrium in the
case of a Gaussian distribution is proved to be faster than for a Bernoulli
distribution for both short-range and long-range lattice potentials. While
exponential decay to equilibrium is excluded in the nonrandom case, it is
proved to occur for both short and long range potentials for Gaussian
distributions, and for potentials of class in the Bernoulli case. Open
problems are discussed.Comment: 10 pages, no figures. This last version, to appear in J. Stat. Phys.,
corrects some minor errors and includes additional references and comments on
the relation to experiment
The Magnetic Field of the Solar Corona from Pulsar Observations
We present a novel experiment with the capacity to independently measure both
the electron density and the magnetic field of the solar corona. We achieve
this through measurement of the excess Faraday rotation due to propagation of
the polarised emission from a number of pulsars through the magnetic field of
the solar corona. This method yields independent measures of the integrated
electron density, via dispersion of the pulsed signal and the magnetic field,
via the amount of Faraday rotation. In principle this allows the determination
of the integrated magnetic field through the solar corona along many lines of
sight without any assumptions regarding the electron density distribution. We
present a detection of an increase in the rotation measure of the pulsar
J18012304 of approximately 160 \rad at an elongation of 0.95 from
the centre of the solar disk. This corresponds to a lower limit of the magnetic
field strength along this line of sight of . The lack of
precision in the integrated electron density measurement restricts this result
to a limit, but application of coronal plasma models can further constrain this
to approximately 20mG, along a path passing 2.5 solar radii from the solar
limb. Which is consistent with predictions obtained using extensions to the
Source Surface models published by Wilcox Solar ObservatoryComment: 16 pages, 4 figures (1 colour): Submitted to Solar Physic
Self-optimization, community stability, and fluctuations in two individual-based models of biological coevolution
We compare and contrast the long-time dynamical properties of two
individual-based models of biological coevolution. Selection occurs via
multispecies, stochastic population dynamics with reproduction probabilities
that depend nonlinearly on the population densities of all species resident in
the community. New species are introduced through mutation. Both models are
amenable to exact linear stability analysis, and we compare the analytic
results with large-scale kinetic Monte Carlo simulations, obtaining the
population size as a function of an average interspecies interaction strength.
Over time, the models self-optimize through mutation and selection to
approximately maximize a community fitness function, subject only to
constraints internal to the particular model. If the interspecies interactions
are randomly distributed on an interval including positive values, the system
evolves toward self-sustaining, mutualistic communities. In contrast, for the
predator-prey case the matrix of interactions is antisymmetric, and a nonzero
population size must be sustained by an external resource. Time series of the
diversity and population size for both models show approximate 1/f noise and
power-law distributions for the lifetimes of communities and species. For the
mutualistic model, these two lifetime distributions have the same exponent,
while their exponents are different for the predator-prey model. The difference
is probably due to greater resilience toward mass extinctions in the food-web
like communities produced by the predator-prey model.Comment: 26 pages, 12 figures. Discussion of early-time dynamics added. J.
Math. Biol., in pres
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