2,917 research outputs found
Toward a Neutrino Mass Matrix
One may identify the general properties of the neutrino mass matrix by
generating many random mass matrices and testing them against the results of
the neutrino experiments.Comment: 3 pages, 1 figure, talk at DPF200
Filtering and scalability in the ECO distributed event model
Event-based communication is useful in many application domains, ranging from small, centralised applications to large, distributed systems. Many different event models have been developed to address the requirements of different application domains. One such model is the ECO model which was designed to support distributed virtual world applications. Like many other event models, ECO has event filtering capabilities meant to improve scalability by decreasing network traffic in a distributed implementation. Our recent work in event-based systems has included building a fully distributed version of the ECO model, including event filtering capabilities. This paper describes the results of our evaluation of filters as a means of achieving increased scalability in the ECO model. The evaluation is empirical and real data gathered from an actual event-based system is used
The Origin of the Boson Peak and the Thermal Conductivity Plateau in Low Temperature Glasses
We argue that the intrinsic glassy degrees of freedom in amorphous solids
giving rise to the thermal conductivity plateau and the ``boson peak'' in the
heat capacity at moderately low temperatures are directly connected to those
motions giving rise to the two-level like excitations seen at still lower
temperatures. These degrees of freedom can be thought of as strongly anharmonic
transitions between the local minima of the glassy energy landscape that are
accompanied by ripplon-like domain wall motions of the glassy mosaic structure
predicted to occur at by the random first order transition theory. The
energy spectrum of the vibrations of the mosaic depends on the glass transition
temperature, the Debye frequency and the molecular length scale. The resulting
spectrum reproduces the experimental low temperature Boson peak. The
``non-universality'' of the thermal conductivity plateau depends on and arises from calculable interactions with the phonons.Comment: 4 pages, submitted to PR
A mixed methods evaluation of an individualised yoga therapy intervention for rheumatoid arthritis: Pilot study
Objectives: to explore patientsā experiences of an individualised yoga therapy intervention for rheumatoid arthritis (RA), specifically in terms of its acceptability and impact on patient-reported outcomes.
Design: Ten patients took part in a 16 week yoga therapy intervention in a hospital setting, consisting of 10 one-to-one consultations with a yoga therapist followed by two group review sessions. Changes in health (EQ-5D, HADS) were assessed pre- and post-intervention and at 12-month follow-up. In-depth interviews were conducted post-intervention and analysed using thematic analysis.
Results: Attendance of the 1-to-1 sessions was high (98%) and all participants reported strong commitment to their personalised home practice. There were significant improvements in measures of depression, anxiety, pain, quality of life and general health at post-intervention and 12-months (p<0.05). In interviews, all but one participant reported positive changes to their symptoms and several reported reductions in their medication and broader benefits such as improved sleep, mood and energy, enabling re-engagement with life. The personally tailored nature of the practice and perceived benefits were key motivational factors. Particular value was placed on the therapeutic function of the consultation and provision of tools to manage stress and build resilience.
Conclusion: This yoga therapy intervention was positively received by patients with RA, with high levels of adherence to both the treatments and tailored home practice. The findings suggest that yoga therapy has potential as an adjunct therapy to improve RA symptoms, increase self-care behaviours and manage stress and negative affect such as anxiety. A larger multi-centre study is therefore warranted
Gathering experience in trust-based interactions
As advances in mobile and embedded technologies coupled with progress in adhoc networking fuel the shift towards ubiquitous computing systems it is becoming increasingly clear that security is a major concern. While this is true of all computing paradigms, the characteristics of ubiquitous systems amplify this concern by promoting spontaneous interaction between diverse heterogeneous entities across administrative boundaries [5]. Entities cannot therefore rely on a specific control authority and will have no global view of the state of the system. To facilitate collaboration with unfamiliar counterparts therefore requires that an entity takes a proactive approach to self-protection. We conjecture that trust management is the best way to provide support for such self-protection measures
Studies on growth rates in pigs and the effect of birth weight
End of project reportThe purpose of this study was to assess some environmental and management factors that affect growth performance on commercial pig units. In experiment 1, a survey was carried out on 22 pig units of known growth performance in south-west Ireland to compare management factors between those showing poor and good growth rates. Low growth rate appears to be due to the cumulative effect of a combination of factors. Experiment 2 was conducted to determine the effects of providing an
additional feeder on performance of weaned piglets. No benefits were
recorded. Feed consumed from the additional feeder was a replacement for
feed that otherwise would have been consumed from the control hopper
feeder.
Experiment 3 was designed to determine if pig performance and efficiency of
growth were affected by weight at birth and at weaning. Lightweight pigs
showed inferior growth performance up to the finisher period. Although they
compensated some of the inferior growth towards the time of slaughter, they
never reached the weights of the heavy birth-weight animals. Males were
either significantly heavier or tended to be heavier than females throughout.
There was no significant difference between the sexes in the number of days
to slaughter. Light and heavy pigs did not differ in the levels of IGF-1 in their
blood plasma; however lightweight pigs had significantly lower IgG preweaning.
Experiment 4 aimed to determine whether piglet birth weight influenced
growth performance, plasma IGF-1 concentrations and muscle fibre
characteristics at day 42 of life. At slaughter (Day 42) light birth weight pigs
were significantly (P < 0.001) lighter. Plasma IGF-1 concentration was lower
by 28% (P=0.06) in light pigs. Muscle fibre cross sectional area and total fibre
number were not significantly different between groups. This study should be
repeated with bigger numbers
Interaction of Arabidopsis Thaliana with Plasmodiophora Brassicae
Plasmodiophora brassicae is a protistan pathogen that attacks roots of brassicaceous plant species causing devastating disease. Resistance is characterised by restriction of the pathogen and susceptibility by the development of severely malformed roots (‘clubroots’) and stunting of the plant that is associated with alterations in the synthesis of cytokinin and auxin hormones. We are examining the susceptible response in Arabidopsis and whether suppression of key resistance factors by the pathogen contributes to susceptibility. The interaction is being studied using a number of approaches including microscopy of the infection process and development of the pathogen within roots and host gene expression analysis. Quantitative PCR was used to confirm the timing of infection of roots and showed that infection occurred at day four and colonisation increased thereafter to high levels by 23 days after inoculation by which time roots were showing systemic abnormalities. To investigate the basis of this compatible interaction we have conducted a time course experiment following infection of a susceptible ecotype of Arabidopsis (Col-0) to examine whole genome geneexpression changes in the host. Differential gene expression analysis of inoculated versus control roots showed that a higher number of genes had altered expression levels at day four compared to that at day seven and at day ten. At day four the expression levels of several genes known to be important for recognition and signal transduction in resistant interactions and genes involved in the biosynthesis of lignin, phenylpropanoids and ethylene were suppressed. Suppression by P. brassicae of specific plant defence responses appears to be a key component of susceptibility in this system.<br /
On the Analytic Structure of the Quark Self-Energy in Nambu-Jona- Lasinio Models
The self-energy of quarks is investigated for various models which are
inspired by the Nambu--Jona-Lasinio (NJL) model. Including, beyond the
Hartree-Fock approximation, terms up to second-order in the quark interaction,
the real and imaginary parts of scalar and vector components of the self-energy
are discussed. The second-order contributions depend on the energy and momentum
of the quark under consideration. This leads to solutions of the Dirac equation
which are significantly different from those of a free quark or a quark with
constant effective mass, as obtained in the Hartree-Fock approximation.Comment: 15 pages LaTeX, 6 figures can be obtained from author
Can a Logarithmically Running Coupling Mimic a String Tension?
It is shown that a Coulomb potential using a running coupling slightly
modified from the perturbative form can produce an interquark potential that
appears nearly linear over a large distance range. Recent high-statistics SU(2)
lattice gauge theory data fit well to this potential without the need for a
linear string-tension term. This calls into question the accuracy of string
tension measurements which are based on the assumption of a constant
coefficient for the Coulomb term. It also opens up the possibility of obtaining
an effectively confining potential from gluon exchange alone.Comment: 13 pages, LaTeX, two figures not included, available from author.
revision - Line lengths fixed so it will tex properl
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