2,007 research outputs found
On homogeneous CR manifolds and their CR algebras
In this paper we show some results on homogeneous CR manifolds, proved by
introducing their associated CR algebras. In particular, we give different
notions of nondegeneracy (generalizing the usual notion for the Levi form)
which correspond to geometrical properties for the corresponding manifolds. We
also give distinguished equivariant CR fibrations for homogeneous CR manifolds.
In the second part of the paper we apply these results to minimal orbits for
the action of a real form of a semisimple Lie group \^G on a flag manifold
\^G/Q.Comment: 14 pages. AMS-LaTeX v2: minor revisio
Framework for better living with HIV in England
Duration: April 2007 - May 2009
Sigma Research was funded by Terrence Higgins Trust to co-ordinate the development of a framework to address the health, social care, support and information needs of people with diagnosed HIV in England. It has now been published as the Framework for better living with HIV in England.
The over-arching goal of the framework is that all people with diagnosed HIV in England "are enabled to have the maximum level of health, well-being, quality of life and social integration". In its explanation of how this should occur the document presents a road map for social care, support and information provision to people with diagnosed HIV in England. By establishing and communicating aims and objectives, the framework should build consensus and provide a means to establish how interventions could be prioritised and coordinated. The key drivers for the framework were clearly articulated ethical principles, agreed by all those who sign up to it, and an inclusive social development / health promotion approach.
Sigma Research worked on the framework with a range of other organisations who sent representatives to a Framework Development Group (see below for membership). The framework is evidence-based and seeks to:
Promote and protect the rights and well-being of all people with HIV in England.
Maximise the capacity of individuals and groups of people with HIV to care for, advocate and represent themselves effectively.
Improve and protect access to appropriate information, social support, social care and clinical services.
Minimise social, economic, governmental and judicial change detrimental to the health and well being of people with HIV.
Alongside the development of the framework, Sigma Research undertook a national needs assessment among people with diagnosed HIV across the UK called What do you need?. These two projects informed and supported each other.
Framework Development Group included:
African HV Policy Network
Black Health Agency
George House Trust
NAM
NAT (National AIDS Trust)
Positively Women
Terrence Higgins Trus
Partners in School: An Innovative Parent-Teacher Consultation Model for Children with Autism Spectrum Disorder
Little research examines the best ways to improve communication between parents and teachers of children with Autism Spectrum Disorder (ASD) and its effect on child outcomes. The present study tests an innovative parent-teacher consultation model, entitled Partners in School. The goal of Partners in School is to improve parent-teacher communication aboutevidence-based practices (EBPs), and subsequently, outcomes for children with ASD. Participants were 26 teachers and 49 parents of children with ASD from a large urban public school district. Parents and teachers completed measures of their communication and child outcomes prior to and after receiving consultation through Partners in School. Results indicated that parents and teachers perceived improvements in child outcomes after participation inPartners in School. Changes in parent- teacher communication also were associated with changes in some child outcomes. Discussionhighlights the important role of communication inconsultations targeting family-school partnerships for children with ASD
Wet chemical synthesis and characterisation of Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3 − δ proton conductor
M. N. Khan would like to thank University of Brunei Darussalam for a Graduate Research Scholarship. L.C. Lim and P. Hing thank UBD, and Government of Brunei Darussalam (S&T 17) for a generous research grant under the UBD Energy programme.Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3 − δ (BSCZGY) proton conducting electrolyte material for intermediate temperature solid oxide fuel cells (IT-SOFCs) has been synthesized by a sol-gel modified Pechini process and its sinterability, thermal expansion, microstructure, ionic conductivity and chemical stability have been investigated. Ionic conductivity at 700 °C was measured to be ~ 8 × 10− 3 S cm− 1 in wet 5 vol.% H2/Ar atmospheres. Chemical stability test in pure CO2 up to 1200 °C shows that the material is highly stable; better than the stability of BaZr0.3Ce0.5Y0.1Yb0.1O3 − δ.PostprintPeer reviewe
Louse- and flea-borne rickettsioses: biological and genomic analyses
In contrast to 15 or more validated and/or proposed tick-borne spotted fever group species, only three named medically important rickettsial species are associated with insects. These insect-borne rickettsiae are comprised of two highly pathogenic species, Rickettsia prowazekii (the agent of epidemic typhus) and R. typhi (the agent of murine typhus), as well as R. felis, a species with unconfirmed pathogenicity. Rickettsial association with obligate hematophagous insects such as the human body louse (R. prowazekii transmitted by Pediculus h. humanus) and several flea species (R. typhi and R. felis, as well as R. prowazekii in sylvatic form) provides rickettsiae the potential for further multiplications, longer transmission cycles and rapid spread among susceptible human populations. Both human body lice and fleas are intermittent feeders capable of multiple blood meals per generation, facilitating the efficient transmission of rickettsiae to several disparate hosts within urban/rural ecosystems. While taking into consideration the existing knowledge of rickettsial biology and genomic attributes, we have analyzed and summarized the interacting features that are unique to both the rickettsiae and their vector fleas and lice. Furthermore, factors that underlie rickettsial changing ecology, where native mammalian populations are involved in the maintenance of rickettsial cycle and transmission, are discussed
Psychological, social and biological correlates of body perception disturbance in complex regional pain syndrome
Body Perception Disturbance (BPD) in Complex Regional Pain Syndrome (CRPS) still represents a poorly understood phenomenon. Research has shown that knowledge about changes in body perception can yield relevant information for understanding and treating the disease. This study addressed possible connections between BPD and psychological and social factors, pain intensity, and disease duration. Sixty patients with chronic CRPS Type I of the hand were recruited. Body Perception Disturbance was assessed using the Galer and Jensen Neurobehavioral Questionnaire (GJ) and the BATH CRPS Body Perception Disturbance Scale (BATH). Depression, anxiety, stress, childhood trauma and other life events were assessed using standardized and validated questionnaires. This study found that BPD in CRPS was significantly correlated with measures of depression, anxiety, current stress, quality of life, and pain intensity, but not with stress experienced in the twelve months preceding onset of illness, childhood trauma, or duration of illness. Future research needs to identify which patients are most likely to develop these psychological conditions of CRPS, so that early, preventive intervention is possible. This study establishes a relationship between depression, anxiety, current stress, quality of life, pain intensity, and BPD severity. It also supports literature suggesting that preexisting stress, childhood trauma, and disease duration have no influence on BPD. The findings suggest that there is a bidirectional influence between brain alterations, psychological symptoms, and illness severity
Simplifying the mosaic description of DNA sequences
By using the Jensen-Shannon divergence, genomic DNA can be divided into
compositionally distinct domains through a standard recursive segmentation
procedure. Each domain, while significantly different from its neighbours, may
however share compositional similarity with one or more distant
(non--neighbouring) domains. We thus obtain a coarse--grained description of
the given DNA string in terms of a smaller set of distinct domain labels. This
yields a minimal domain description of a given DNA sequence, significantly
reducing its organizational complexity. This procedure gives a new means of
evaluating genomic complexity as one examines organisms ranging from bacteria
to human. The mosaic organization of DNA sequences could have originated from
the insertion of fragments of one genome (the parasite) inside another (the
host), and we present numerical experiments that are suggestive of this
scenario.Comment: 16 pages, 1 figure, Accepted for publication in Phys. Rev.
Structural and doping effects in the half-metallic double perovskite CrWO
he structural, transport, magnetic and optical properties of the double
perovskite CrWO with have been studied. By
varying the alkaline earth ion on the site, the influence of steric effects
on the Curie temperature and the saturation magnetization has been
determined. A maximum K was found for SrCrWO having an almost
undistorted perovskite structure with a tolerance factor . For
CaCrWO and BaCrWO structural changes result in a strong
reduction of . Our study strongly suggests that for the double perovskites
in general an optimum is achieved only for , that is, for an
undistorted perovskite structure. Electron doping in SrCrWO by a
partial substitution of Sr by La was found to reduce both
and the saturation magnetization . The reduction of could be
attributed both to band structure effects and the Cr/W antisites induced by
doping. Band structure calculations for SrCrWO predict an energy gap in
the spin-up band, but a finite density of states for the spin-down band. The
predictions of the band structure calculation are consistent with our optical
measurements. Our experimental results support the presence of a kinetic energy
driven mechanism in CrWO, where ferromagnetism is stabilized by a
hybridization of states of the nonmagnetic W-site positioned in between the
high spin Cr-sites.Comment: 14 pages, 10 figure
Surfactant protein D increases fusion of Mycobacterium tuberculosis- containing phagosomes with lysosomes in human macrophages
Lung surfactant protein D (SP-D) binds to Mycobacterium tuberculosis surface lipoarabinomannan and results in bacterial agglutination, reduced uptake, and inhibition of growth in human macrophages. Here we show that SP-D limits the intracellular growth of bacilli in macrophages by increasing phagosome-lysosome fusion but not by generating a respiratory burst
Identifying the favored mutation in a positive selective sweep.
Most approaches that capture signatures of selective sweeps in population genomics data do not identify the specific mutation favored by selection. We present iSAFE (for "integrated selection of allele favored by evolution"), a method that enables researchers to accurately pinpoint the favored mutation in a large region (∼5 Mbp) by using a statistic derived solely from population genetics signals. iSAFE does not require knowledge of demography, the phenotype under selection, or functional annotations of mutations
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