2,341 research outputs found
Radial basis functions for the sphere
In this paper we compute the ultraspherical series expansions for the more commonly used radial basis functions. In several special cases we provide asymptotic estimates for the decay rate of the coefficients involved. knowledge of the decay rate of these coefficients is useful because they enable error estimates for spherical interpolation
Integration of informal music technologies in secondary school music lessons
date-added: 2011-08-12 11:03:06 +0100 date-modified: 2011-08-12 11:03:38 +0100date-added: 2011-08-12 11:03:06 +0100 date-modified: 2011-08-12 11:03:38 +0100This project was supported by EPSRC grant EP/I001832/1, ‘Musicology for the masses’
Local service provision of Augmentative and Alternative Communication and communication aids in England
BACKGROUND: Provision of Augmentative and Alternative Communication (AAC) interventions have been acknowledged to be highly variable in England and elsewhere. OBJECTIVE: The aim of the project described in this paper was to provide data to inform service planning and delivery of services delivering AAC including communication aids. METHODS: A survey was developed by an expert group and administered by telephone interview to service managers of primary and secondary services providing AAC interventions at a local level in England and data were included from two hundred and twenty respondents. RESULTS: Services included had mean caseload sizes of 0.09% of the catchment population for AAC provision, with a mean of 0.017% of the catchment population for high tech communication aids. Significantly higher levels of caseload and spend were reported for services working with children and young people as compared to those working with adults. Mean levels of unmet need for AAC equating to approximately one in every eight individuals on services' caseloads were reported. CONCLUSIONS: Although these data should be treated with caution, they suggest a significant level of variation of provision of AAC by local services
Deep mitochondrial divergence within a Heliconius butterfly species is not explained by cryptic speciation or endosymbiotic bacteria.
BACKGROUND: Cryptic population structure can be an indicator of incipient speciation or historical processes. We investigated a previously documented deep break in the mitochondrial haplotypes of Heliconius erato chestertonii to explore the possibility of cryptic speciation, and also the possible presence of endosymbiont bacteria that might drive mitochondrial population structure. RESULTS: Among a sample of 315 individuals from 16 populations of western Colombia, two principal mtDNA clades were detected with 2.15% divergence and we confirmed this structure was weakly associated with geography. The first mtDNA clade included 87% of individuals from northern populations and was the sister group of H. erato members of Andes western, while the second clade contained most individuals from southern populations (78%), which shared haplotypes with an Ecuadorian race of H. erato. In contrast, analysis using AFLP markers showed H. e. chestertonii to be a genetically homogeneous species with no association between mitochondrial divergence and AFLP structure. The lack of congruence between molecular markers suggests that cryptic speciation is not a plausible explanation for the deep mitochondrial divergence in H. e chestertonii. We also carried out the first tests for the presence of endosymbiontic bacteria in Heliconius, and identified two distinct lineages of Wolbachia within H. e. chestertonii. However, neither of the principal mitochondrial clades of H. e. chestertonii was directly associated with the patterns of infection. CONCLUSIONS: We conclude that historical demographic processes are the most likely explanation for the high mitochondrial differentiation in H. e. chestertonii, perhaps due to gene flow between Cauca valley H. e. chestertonii and west Pacific slope populations of H. erato.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Absence of Phase Transition for Antiferromagnetic Potts Models via the Dobrushin Uniqueness Theorem
We prove that the -state Potts antiferromagnet on a lattice of maximum
coordination number exhibits exponential decay of correlations uniformly at
all temperatures (including zero temperature) whenever . We also prove
slightly better bounds for several two-dimensional lattices: square lattice
(exponential decay for ), triangular lattice (), hexagonal
lattice (), and Kagom\'e lattice (). The proofs are based on
the Dobrushin uniqueness theorem.Comment: 32 pages including 3 figures. Self-unpacking file containing the tex
file, the needed macros (epsf.sty, indent.sty, subeqnarray.sty, and
eqsection.sty) and the 3 ps file
The systemic and global dimension of business resilience in a socio-technical perspective
This paper proposes to augment the concept of a business resilience improving process by enlarging such a process with a dimension of external action that addresses the vaster frame of systemic resilience of our societies. To this aim, I propose to widen the concept of socio-technical system (STS) to human societies, based on the idea that the development and survival of human societies has necessary social and technical factors. I also propose a concept of resilience in terms of dealing with failures of STS. Two particular cases of very large failure avoidance are considered: nuclear war and civilizational collapse, and I propose that such cases should be present in the referred dimension of external action of any business resilience program. Because the action of public governments and their cooperation is crucial for advancing global systemic resilience, I suggest that businesses should analyze and model the decisions of governments in a wider context of naturally occurring cooperating and conflicting human groups.I would like to thank the two anonymous reviewers for criticisms that allowed me to sharpen the generalized concept of socio-technical system and to fuse a general concept of global resilience with business resilience. This paper was financially supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT-Fundacao para a Ciencia e Tecnologia within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio
Deep mitochondrial divergence within a Heliconius butterfly species is not explained by cryptic speciation or endosymbiotic bacteria
Background: Cryptic population structure can be an indicator of incipient speciation or historical processes. We investigated a previously documented deep break in the mitochondrial haplotypes of Heliconius erato chestertonii to explore the possibility of cryptic speciation, and also the possible presence of endosymbiont bacteria that might drive mitochondrial population structure. Results: Among a sample of 315 individuals from 16 populations of western Colombia, two principal mtDNA clades were detected with 2.15% divergence and we confirmed this structure was weakly associated with geography. The first mtDNA clade included 87% of individuals from northern populations and was the sister group of H. erato members of Andes western, while the second clade contained most individuals from southern populations (78%), which shared haplotypes with an Ecuadorian race of H. erato. In contrast, analysis using AFLP markers showed H. e. chestertonii to be a genetically homogeneous species with no association between mitochondrial divergence and AFLP structure. The lack of congruence between molecular markers suggests that cryptic speciation is not a plausible explanation for the deep mitochondrial divergence in H. e chestertonii. We also carried out the first tests for the presence of endosymbiontic bacteria in Heliconius, and identified two distinct lineages of Wolbachia within H. e. chestertonii. However, neither of the principal mitochondrial clades of H. e. chestertonii was directly associated with the patterns of infection. Conclusions: We conclude that historical demographic processes are the most likely explanation for the high mitochondrial differentiation in H. e. chestertonii, perhaps due to gene flow between Cauca valley H. e. chestertonii and west Pacific slope populations of H. erato. © 2011 Mũoz et al; licensee BioMed Central Ltd
Scottish leaders’ debates on Twitter: Sturgeon, Davidson, and ‘indyref2’ dominated proceedings
As the dust begins to settle on the 2017 General Election campaign, Graeme Baxter, Simon Burnett, John Isaacs, Iain MacLeod, Sarah Pedersen, and Elizabeth Tait reflect upon the Twitter response to the two televised Scottish leaders’ debates held in the lead-up to polling day
Interacting anyons in topological quantum liquids: The golden chain
We discuss generalizations of quantum spin Hamiltonians using anyonic degrees
of freedom. The simplest model for interacting anyons energetically favors
neighboring anyons to fuse into the trivial (`identity') channel, similar to
the quantum Heisenberg model favoring neighboring spins to form spin singlets.
Numerical simulations of a chain of Fibonacci anyons show that the model is
critical with a dynamical critical exponent z=1, and described by a
two-dimensional conformal field theory with central charge c=7/10. An exact
mapping of the anyonic chain onto the two-dimensional tricritical Ising model
is given using the restricted-solid-on-solid (RSOS) representation of the
Temperley-Lieb algebra. The gaplessness of the chain is shown to have
topological origin.Comment: 5 pages, 4 figure
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