1,571 research outputs found
Mutual information for examining correlations in DNA
This paper examines two methods for finding whether long-range correlations
exist in DNA: a fractal measure and a mutual information technique. We evaluate
the performance and implications of these methods in detail. In particular we
explore their use comparing DNA sequences from a variety of sources. Using
software for performing in silico mutations, we also consider evolutionary
events leading to long range correlations and analyse these correlations using
the techniques presented. Comparisons are made between these virtual sequences,
randomly generated sequences, and real sequences. We also explore correlations
in chromosomes from different species.Comment: 8 pages, 3 figure
Widths of Hypernuclear States
The and neutron decay widths of hypernuclear states, based on
calculated \Xi N \to \lala mixing amplitudes, are estimated. The widths which
result from using the Nijmegen Model D interaction are sufficiently small, of
order 1.5 MeV, that experiments to observe hypernuclear states using the
reaction may be feasible.Comment: 20 pages, LaTex with one postscript figure in accompanying file, to
appear in Progress of Theoretical Physics Supplement No. 11
SIMP (Strongly Interacting Massive Particle) Search
We consider laboratory experiments that can detect stable, neutral strongly
interacting massive particles (SIMPs). We explore the SIMP annihilation cross
section from its minimum value (restricted by cosmological bounds) to the barn
range, and vary the mass values from a GeV to a TeV. We also consider the
prospects and problems of detecting such particles at the Tevatron.Comment: Latex. 7 pages, 1 eps figure. Proceedings to the 4th UCLA Symposium
on Dark Matter DM2000, Marina del Rey, CA, USA, Feb. 23-25, 200
The influence of strength of hyperon-hyperon interactions on neutron star properties
An equation of state of neutron star matter with strange baryons has been
obtained. The effects of the strength of hyperon-hyperon interactions on the
equations of state constructed for the chosen parameter sets have been
analyzed. Numerous neutron star models show that the appearance of hyperons is
connected with the increasing density in neutron star interiors. The performed
calculations have indicated that the change of the hyperon-hyperon coupling
constants affects the chemical composition of a neutron star. The obtained
numerical hyperon star models exclude large population of strange baryons in
the star interior.Comment: 18 pages, 22 figures, accepted to be published in Journal of Physics
G: Nuclear and Particle Physic
Chiral SU(3) Symmetry and Strangeness
In this talk we review recent progress on the systematic evaluation of the
kaon and antikaon spectral functions in dense nuclear matter based on a chiral
SU(3) description of the low-energy pion-, kaon- and antikaon-nucleon
scattering data.Comment: 9 pages, 4 figures, invited talk given by M.F.M.L. at the SQM2001
conferenc
Biophysical models of persistent connectivity and barriers on the northern Mid-Atlantic Ridge
A precautionary approach to protecting biodiversity on mid-ocean ridges, while permitting seabed mining, is to
design and implement a network of areas protected from the effects of mining. Such a network should capture
representative populations of vent endemic fauna within regions of connectivity and across persistent barriers,
but determining where such connectivity and barriers exist is challenging. A promising approach is to use biophysical modeling to infer the spatial scale of dispersal and the positions where breaks in hydrographic connectivity occur. We use results from a deep-sea biophysical model driven by data from the global array of Argo
probes for depths of 1000 m to estimate biophysical connectivity among fragmented hydrothermal vent habitats
along the Mid-Atlantic Ridge, from the equator northward to the Portuguese Exclusive Economic Zone surrounding the Azores. The spatial scale of dispersal varies along the ridge axis, with median dispersal distances for
planktonic larval durations (PLDs) of 75 d ranging from 67 km to 304 km. This scale of dispersal leads to
considerable opportunities for connectivity through mid-water dispersal. A stable pattern of five regions of
biophysical connectivity was obtained for PLDs of 100 d or more. Connectivity barriers between these regions
can persist even when planktonic larval duration extends beyond 200 d. For a 50 d PLD, one connectivity barrier
coincides with the region of the genetic hybrid zone for northern and southern vent mussel species at the Broken
Spur vent field. Additional barriers suggest potential for genetic differentiation that so far has not been detected
for any taxon. The locations of persistent zones of connectivity and barriers to dispersal suggest that there may be
multiple biogeographic subunits along the northern Mid-Atlantic Ridge that should be taken into account in
planning for effective environmental management of human activities
Microscopic approach to pion-nucleus dynamics
Elastic scattering of pions from finite nuclei is investigated utilizing a
contemporary, momentum--space first--order optical potential combined with
microscopic estimates of second--order corrections. The calculation of the
first--order potential includes:\ \ (1)~full Fermi--averaging integration
including both the delta propagation and the intrinsic nonlocalities in the
- amplitude, (2)~fully covariant kinematics, (3)~use of invariant
amplitudes which do not contain kinematic singularities, and (4)~a
finite--range off--shell pion--nucleon model which contains the nucleon pole
term. The effect of the delta--nucleus interaction is included via the mean
spectral--energy approximation. It is demonstrated that this produces a
convergent perturbation theory in which the Pauli corrections (here treated as
a second--order term) cancel remarkably against the pion true absorption terms.
Parameter--free results, including the delta--nucleus shell--model potential,
Pauli corrections, pion true absorption, and short--range correlations are
presented. (2 figures available from authors)Comment: 13 page
Safety of Log Transportation After Regulation and Training in the State of Georgia, USA
Mechanical failure rates observed in highway accidents involving logging tractor-trailers have fallen significantly since Georgia subjected these vehicles to random roadside inspections. This improvement is attributed to both the regulation and the training efforts aimed at the log trucking community immediately before and after the implementation of the rules
Alternatives to mental health admissions for children and adolescents experiencing mental health crises: A systematic review of the literature
Background: Many children and young people (CYP) presenting with mental health crises are admitted to hospital due to concerns around illness severity and risk. Whilst inpatient admissions have an important role for such children, there are a number of burdens associated with them, and safe avoidance of admissions is favourable. We systematically reviewed the literature for studies of interventions reported as alternatives to a hospital admission in CYP presenting with mental health crises, in any inpatient setting. Methods: Three databases (PsychInfo, PubMed and Web of Science) were searched for peer-reviewed papers in October 2020, with an updated search in May 2021. Results: We identified 19 papers of interventions delivered in the emergency department, the home, outside of home but outside of clinics and in hospital clinics. The quality of most included studies was low, with less than half being randomised controlled trials and only half of these at low risk of bias. The best quality studies and greatest evidence for efficacy came from in-home interventions, in particular multisystemic therapy, which improved psychological outcomes, and though a large number of CYP still ended up being admitted, there appeared to be decreased length of stay. Conclusions: Overall, we could not recommend a particular intervention as an alternative to inpatient admission; however, our review describes benefits across a range of types of interventions that might be considered in multi-modal treatments. We also provide recommendations for future research, in particular the evaluation of new interventions as they emerge
Does the advent of modern implant systems and the refinement of free flap technique negate the effect of radiotherapy in oral cancer dental implant based oral rehabilitation
Aim: The aim of this study was to see whether the advent of modern implant systems, and the refinement of free flap techniques, negate the effect of radiotherapy in patients with oral cancer who undergo dental implantâbased oral rehabilitation.
Materials and method: A retrospective study was performed to look at the success rates of implants placed in all patients, in a 3 year period at the Queen Elizabeth Hospital, Birmingham. Survival rates in irradiated patients were compared with success rates in patients who did receive radiotherapy.
Results and conclusions: The rate of failure is comparable in the no radiotherapy group (1.12%) and post-radiotherapy group (1.76%). Our study shows that there was no significant difference in survival when implants were placed in native, grafted bone or in free flap reconstructions in irradiated head and neck cancer patients. Ultimately, the current evidence is not strong enough to prove whether the advent of modern implants systems, and the refinement of free flap techniques,
does negate the effect of radiotherapy in patients with oral cancer undergoing dental implantâbased oral rehabilitation. There is a need to perform a prospective clinical trial to observe clinical outcomes in both patients who have received radiotherapy and those who have not received radiotherap
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