5,067 research outputs found
Quality of Life in a Mixed Ethnic Population after Myocardial Infarction
Background: Although South Asian people are a significant ethnic group at increased risk of coronary heart disease and high mortality rates and experience greater delays with respect to diagnosis, referral and treatment, comparatively little is known about their quality of life during recovery from a myocardial infarction.Objectives: We sought to determine and compare the impact of ethnicity on quality of life after myocardial infarction (MI) in a mixed ethnic population (South Asian and white people) in the UK.Methods: A 2x2 mixed-group design with repeated measures on the second factor. The independent variables were ethnic group (white/South Asian) and time since MI (2 weeks/3 months). The dependent variables were the subscale scores on the Short-Form 36-item health survey (SF-36) and the Hospital Anxiety and Depression Scale (HADS).Results: At 2 weeks, significant differences were observed between groups on 5 of the 8 SF-36 subscale domain scores, with the white group reporting higher quality of life. Significant improvement in reported quality of life occurred in both groups over time on all domains of the SF-36, except bodily pain. There was a significantly greater improvement in favour of the white group for the role-physical domain. There was no significant difference between groups in terms of anxiety or depression at 2 weeks. Both groups showed a significant reduction in anxiety and depression by 3 months, but the degree of reduction was not significantly different between them. At 3 months, there was no significant difference between groups in terms of anxiety scores, but the South Asian group scored significantly higher on the depression scale.Conclusions: South Asian people have significantly poorer quality of life than white people after MI. While both groups showed improvement over time, South Asian people reported significantly less improvement in physical role function and were more depressed at 3 months. Identifying the factors accounting for such differences is important to develop models of care for delivering the most effective and culturally-sensitive interventions to this group
Optical fibre digital pulse-position-modulation assuming a Gaussian received pulse shape
The abundance in bandwidth available in the best monomode fibres may be exchanged for improved receiver sensitivity by employing digital PPM. The paper presents a performance and optimisation analysis for a digital PPM coding scheme operating over a fibre channel employing a PIN-BJT receiver and assuming a Gaussian received pulse shape. The authors present original results for a 50 Mbit/s, 1.3 μm wavelength digital PPM system and conclude that, provided the fibre bandwidth is several times that of the data rate, digital PPM can outperform commercially available PIN-BJT binary PCM system
Quantum dot emission from site-controlled ngan/gan micropyramid arrays
InxGa1−xN quantum dots have been fabricated by the selective growth of GaN micropyramid arrays topped with InGaN/GaN quantum wells. The spatially, spectrally, and time-resolved emission properties of these structures were measured using cathodoluminescence hyperspectral imaging and low-temperature microphotoluminescence spectroscopy. The presence of InGaN quantum dots was confirmed directly by the observation of sharp peaks in the emission spectrum at the pyramid apices. These luminescence peaks exhibit decay lifetimes of approximately 0.5 ns, with linewidths down to 650 me
Protease inhibitor (Pi) locus, fertility and twinning
In a sample of 160 Dutch twin pairs and their parents, we found that mothers of dizygotic twins had frequencies of the S and Z alleles at the protease inhibitor (Pi) locus that were 3 times higher than a control sample. Mothers of identical twins also had a higher frequency of S than controls. The S allele may thus both increase ovulation rate and enhance the success of multiple pregnancies. There was also an increased frequency of the S allele in fathers of dizygotic twins; however, this may be a secondary effect of assortative mating for family size (indicating by the number of siblings of the parents), for which a correlation of 0.2 was observed. Parents of dizygotic twins came from larger families than parents of monozygotic twins, but no effect of Pi type on family size was seen. © 1992 Springer-Verlag
The data cyclotron query processing scheme
Distributed database systems exploit static workload characteristics to steer data fragmentation and data allocation schemes. However, the grand challenge of distributed query processing is to come up with a self-organizing architecture, which exploits all resources to manage the hot data set, minimize query response time, and maximize throughput without global co-ordination.
In this paper, we introduce the Data Cyclotron architecture which addresses the challenges using turbulent data movement through a storage ring built from distributed main memory capitalizing modern remote-DMA facilities. Queries assigned to individual nodes interact with the Data Cyclotron by picking up data fragments continuously flowing around, i.e., the hot set.
Each data fragment carries a level of interest (LOI) metric, which represents the cumulative query interest as the fragment passes around the ring multiple times. A fragment with a LOI below a given threshold, inversely proportional to the ring load, is pulled o
Minke whales change their swimming behavior with respect to their calling behavior, nearby conspecifics, and the environment in the central North Pacific
This research was supported by the Office of Naval Research (Code 322, Award Number N0001422WX01263), Commander, U.S. Pacific Fleet (Code N465JR, Award Number N0007023WR0EP8F), and tool development necessary for this analysis was supported by the U.S. Navy’s Living Marine Resources Program (Award Number N0002520WR0141R). AcknowledgmentsBehavioral responses to sonar have been observed in a number of baleen whales, including minke whales (Balaenoptera acutorostrata). Previous studies used acoustic minke whale boing detections to localize and track individual whales on the U.S. Pacific Missile Range Facility (PMRF) in Kaua ‘i, Hawai‘i before, during, and after Navy training activities. These analyses showed significant changes in central North Pacific minke whale distribution and swimming behavior during Navy sonar events. For the purposes of contextualizing changes in animal movement relative to Navy sonar, we expanded on this research to examine the natural variation in minke whale movement when Navy sonar was not present. This study included 2,245 acoustically derived minke whale tracks spanning the years 2012–2017 over all months that minke whales were detected (October–May). Minke whale movement was examined relative to calling season, day of the year, hour of day, wind speed, calling state (nominal or rapid), and distance to the nearest calling conspecific. Hidden Markov models were used to identify two kinematic states (slower, less directional movement and faster, more directional movement). The findings indicate that minke whales were more likely to travel in a faster and more directional state when they were calling rapidly, when other vocalizing minke whales were nearby, during certain times of the day and calling seasons, and in windier conditions, but these changes in movement were less intense than the changes observed during exposure to Navy sonar, when swim speeds were the fastest. These results start to put behavioral responses to Navy sonar into an environmental context to understand the severity of responses relative to natural changes in behavior.Publisher PDFPeer reviewe
Probing crystallisation of a fluoro-apatite - mullite system using neutron diffraction
Real-time small angle neutron scattering and wide angle neutron scattering studies were undertaken concurrently on a glass ionomer of nominal composition 4.5(SiO2)-3(Al2O3)-1.5(P2O5)-3(CaO)-2(CaF2). Neutron studies were conducted as a function of temperature to investigate the crystallisation process. No amorphous phase separation was observed at room temperature and the onset of crystallisation was found to occur at 650°C, which is 90°C lower than previously reported. The first crystalline phase observed corresponded to fluorapatite; it was only upon further heating was the mullite phase became present. The crystallite size at 650°C was found to be ~115Å and the result was consistent across all measurements
Positive solutions of Schr\"odinger equations and fine regularity of boundary points
Given a Lipschitz domain in and a nonnegative
potential in such that is bounded
in we study the fine regularity of boundary points with respect to
the Schr\"odinger operator in . Using potential
theoretic methods, several conditions equivalent to the fine regularity of are established. The main result is a simple (explicit if
is smooth) necessary and sufficient condition involving the size of
for to be finely regular. An essential intermediate result consists in
a majorization of for
positive harmonic in and . Conditions for
almost everywhere regularity in a subset of are also
given as well as an extension of the main results to a notion of fine
-regularity, if , being two potentials, with and a second order elliptic operator.Comment: version 1. 23 pages version 3. 28 pages. Mainly a typo in Theorem 1.1
is correcte
Semi-spheroidal Quantum Harmonic Oscillator
A new single-particle shell model is derived by solving the Schr\"odinger
equation for a semi-spheroidal potential well. Only the negative parity states
of the component of the wave function are allowed, so that new magic
numbers are obtained for oblate semi-spheroids, semi-sphere and prolate
semi-spheroids. The semi-spherical magic numbers are identical with those
obtained at the oblate spheroidal superdeformed shape: 2, 6, 14, 26, 44, 68,
100, 140, ... The superdeformed prolate magic numbers of the semi-spheroidal
shape are identical with those obtained at the spherical shape of the
spheroidal harmonic oscillator: 2, 8, 20, 40, 70, 112, 168 ...Comment: 4 pages, 3 figures, 1 tabl
Peak Performance – Remote Memory Revisited
Many database systems share a need for large amounts of
fast storage. However, economies of scale limit the utility
of extending a single machine with an arbitrary amount
of memory. The recent broad availability of the zero-copy
data transfer protocol RDMA over low-latency and high
throughput network connections such as InfiniBand prompts
us to revisit the long-proposed usage of memory provided
by remote machines. In this paper, we present a solution
to make use of remote memory without manipulation of the
operating system, and investigate the impact on database
performance
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