978 research outputs found
Telephone multiline signaling using common signal pair
An operator can rapidly and automatically produce coded electrical signals by manipulating mechanical thumb wheel switches so as to instruct a service center to connect any number of telephone lines to the console thus enabling the operator to listen and/or talk over several lines simultaneously. The system includes an on-site console having several mechanically operated thumb wheel switches to which the desired lines to be connected can be dialed in. Electrical coded signals are fed to a number of banks of line AND gates representing units, tens and hundreds, a group of channel gates, and a command gate. These signals are gated out in a controlled manner to an encoder which generates tones that are transmitted over a single line to a communication service center
Ab initio calculation of the KRb dipole moments
The relativistic configuration interaction valence bond method has been used
to calculate permanent and transition electric dipole moments of the KRb
heteronuclear molecule as a function of internuclear separation. The permanent
dipole moment of the ground state potential is found to be
0.30(2) at the equilibrium internuclear separation with excess negative
charge on the potassium atom. For the potential the dipole moment
is an order of magnitude smaller (1 Cm) In addition, we
calculate transition dipole moments between the two ground-state and
excited-state potentials that dissociate to the K(4s)+Rb(5p) limits. Using this
data we propose a way to produce singlet KRb molecules by a
two-photon Raman process starting from an ultracold mixture of doubly
spin-polarized ground state K and Rb atoms. This Raman process is only allowed
due to relativistic spin-orbit couplings and the absence of gerade/ungerade
selection rules in heteronuclear dimers.Comment: 16 pages, 7 figure
A Combination Theorem for Metric Bundles
We define metric bundles/metric graph bundles which provide a purely
topological/coarse-geometric generalization of the notion of trees of metric
spaces a la Bestvina-Feighn in the special case that the inclusions of the edge
spaces into the vertex spaces are uniform coarsely surjective quasi-isometries.
We prove the existence of quasi-isometric sections in this generality. Then we
prove a combination theorem for metric (graph) bundles (including exact
sequences of groups) that establishes sufficient conditions, particularly
flaring, under which the metric bundles are hyperbolic. We use this to give
examples of surface bundles over hyperbolic disks, whose universal cover is
Gromov-hyperbolic. We also show that in typical situations, flaring is also a
necessary condition.Comment: v3: Major revision: 56 pages 5 figures. Many details added.
Characterization of convex cocompact subgroups of mapping class groups of
surfaces with punctures in terms of relative hyperbolicity given v4: Final
version incorporating referee comments: 63 pages 5 figures. To appear in
Geom. Funct. Ana
Calcisponges have a ParaHox gene and dynamic expression of dispersed NK homeobox genes
This study was funded by the Sars Centre core budget to M. Adamska. Sequencing was performed at the Norwegian High Throughput Sequencing Centre funded by the Norwegian Research Council. O.M.R. and D.E.K.F. acknowledge support from the BBSRC and the School of Biology, University of St Andrews.Sponges are simple animals with few cell types, but their genomes paradoxically contain a wide variety of developmental transcription factors1,2,3,4, including homeobox genes belonging to the Antennapedia (ANTP) class5,6, which in bilaterians encompass Hox, ParaHox and NK genes. In the genome of the demosponge Amphimedon queenslandica, no Hox or ParaHox genes are present, but NK genes are linked in a tight cluster similar to the NK clusters of bilaterians5. It has been proposed that Hox and ParaHox genes originated from NK cluster genes after divergence of sponges from the lineage leading to cnidarians and bilaterians5,7. On the other hand, synteny analysis lends support to the notion that the absence of Hox and ParaHox genes in Amphimedon is a result of secondary loss (the ghost locus hypothesis)8. Here we analysed complete suites of ANTP-class homeoboxes in two calcareous sponges, Sycon ciliatum and Leucosolenia complicata. Our phylogenetic analyses demonstrate that these calcisponges possess orthologues of bilaterian NK genes (Hex, Hmx and Msx), a varying number of additional NK genes and one ParaHox gene, Cdx. Despite the generation of scaffolds spanning multiple genes, we find no evidence of clustering of Sycon NK genes. All Sycon ANTP-class genes are developmentally expressed, with patterns suggesting their involvement in cell type specification in embryos and adults, metamorphosis and body plan patterning. These results demonstrate that ParaHox genes predate the origin of sponges, thus confirming the ghost locus hypothesis8, and highlight the need to analyse the genomes of multiple sponge lineages to obtain a complete picture of the ancestral composition of the first animal genome.PostprintPeer reviewe
Football and dementia: A qualitative investigation of a community based sports group for men with early onset dementia
This study investigates the impact of a weekly group providing sport and physical activities for men with early onset dementia established by Notts County Football in the Community (NCFC). There were three aims: investigate the effect of early onset dementia on individuals with the condition and their carers; examine perceptions of current levels of service provision for people with early onset dementia; and analyse the impact of the group. Men with dementia (n=5) attending the sessions, their carers (n=5), NCFC coaching staff (n=5) and people organising/facilitating the sessions (n=5), were interviewed. Semi-structured interviews explored the participants’ experiences of dementia, their opinions on current service provisions and on the sessions. Data were analysed using thematic analysis. Four main themes were found: loss related to the condition of dementia and its impact on relationships (‘Loss’); lack of age-appropriate services for people with early onset dementia (‘Lack of Resources’); enjoyment and positive anticipation related to the group for all involved (‘Enjoyment and Anticipation’); and ‘the Notts County Effect’ which attributed the success of the sessions to the strong brand of the football club, and to personalised service in a “dementia-free” environment. The NCFC sessions provided a safe low-cost intervention with positive effects upon quality of life for both people with early onset dementia, their carers and the staff involved. This suggests that the service may be valuable to a wider range of people living in different area
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