10,676 research outputs found
Direct photons in d+Au and p+p collisions
Results are presented from an ongoing analysis of direct photon production
with the STAR experiment at RHIC. The direct photon measurement in d+Au
collisions and the neutral pion spectrum in p+p collisions are found to be in
agreement with NLO pQCD calculations.Comment: 4 pages, 3 figures, proceedings of Quark Matter 200
The Cognitive Daisy – a novel method for recognising the cognitive status of older adults in residential care: Innovative practice
The Cognitive Daisy (COG-D) is an innovative assessment system created to provide
healthcare staff with an instant snapshot of the cognitive status of older adults in
residential care. The COG-D comprises a flower head consisting of 15 colour coded
petals depicting information about: visual-spatial perception, comprehension,
communication, memory and attention. This study confirmed the practicality of the
COG-D protocol for assessing cognition in a sample of 33 older adults living in
residential care and endorsed the use of the COG-D as a tool for recognising the
cognitive status of care home residents
Defect filtering for thermal expansion induced dislocations in III-V lasers on silicon
Epitaxially integrated III-V semiconductor lasers for silicon photonics have
the potential to dramatically transform information networks, but currently,
dislocations limit performance and reliability even in defect tolerant InAs
quantum dot (QD) based lasers. Despite being below critical thickness, QD
layers in these devices contain previously unexplained misfit dislocations,
which facilitate non-radiative recombination. We demonstrate here that these
misfit dislocations form during post-growth cooldown due to the combined
effects of (1) thermal-expansion mismatch between the III-V layers and silicon
and (2) precipitate and alloy hardening in the active region. By incorporating
an additional sub-critical thickness, indium-alloyed misfit dislocation
trapping layer, we leverage these mechanical hardening effects to our
advantage, successfully displacing 95% of misfit dislocations from the QD layer
in model structures. Unlike conventional dislocation mitigation strategies, the
trapping layer reduces neither the number of threading dislocations nor the
number of misfit dislocations. It simply shifts the position of misfit
dislocations away from the QD layer, reducing the defects' impact on
luminescence. In full lasers, adding a misfit dislocation trapping layer both
above and below the QD active region displaces misfit dislocations and
substantially improves performance: we measure a twofold reduction in lasing
threshold currents and a greater than threefold increase in output power. Our
results suggest that devices employing both traditional threading dislocation
reduction techniques and optimized misfit dislocation trapping layers may
finally lead to fully integrated, commercially viable silicon-based photonic
integrated circuits.Comment: 9 pages, 6 figure
Evaluation of early and late presentation of patients with ocular mucous membrane pemphigoid to two major tertiary referral hospitals in the United Kingdom
PURPOSE: Ocular mucous membrane pemphigoid (OcMMP) is a sight-threatening autoimmune disease in which referral to specialists units for further management is a common practise. This study aims to describe referral patterns, disease phenotype and management strategies in patients who present with either early or established disease to two large tertiary care hospitals in the United Kingdom.\ud
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PATIENTS AND METHODS: In all, 54 consecutive patients with a documented history of OcMMP were followed for 24 months. Two groups were defined: (i) early-onset disease (EOD:<3 years, n=26, 51 eyes) and (ii) established disease (EstD:>5 years, n=24, 48 eyes). Data were captured at first clinic visit, and at 12 and 24 months follow-up. Information regarding duration, activity and stage of disease, visual acuity (VA), therapeutic strategies and clinical outcome were analysed.\ud
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RESULTS: Patients with EOD were younger and had more severe conjunctival inflammation (76% of inflamed eyes) than the EstD group, who had poorer VA (26.7%=VA<3/60, P<0.01) and more advanced disease. Although 40% of patients were on existing immunosuppression, 48% required initiation or switch to more potent immunotherapy. In all, 28% (14) were referred back to the originating hospitals for continued care. Although inflammation had resolved in 78% (60/77) at 12 months, persistence of inflammation and progression did not differ between the two phenotypes. Importantly, 42% demonstrated disease progression in the absence of clinically detectable inflammation.\ud
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CONCLUSIONS: These data highlight that irrespective of OcMMP phenotype, initiation or escalation of potent immunosuppression is required at tertiary hospitals. Moreover, the conjunctival scarring progresses even when the eye remains clinically quiescent. Early referral to tertiary centres is recommended to optimise immunosuppression and limit long-term ocular damage.\ud
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A new procedure for determining the genetic basis of a physiological process in a non-model species, illustrated by cold induced angiogenesis in the carp
<p>Abstract</p> <p>Background</p> <p>Physiological processes occur in many species for which there is yet no sequenced genome and for which we would like to identify the genetic basis. For example, some species increase their vascular network to minimise the effects of reduced oxygen diffusion and increased blood viscosity associated with low temperatures. Since many angiogenic and endothelial genes have been discovered in man, functional homolog relationships between carp, zebrafish and human were used to predict the genetic basis of cold-induced angiogenesis in <it>Cyprinus Carpio </it>(carp). In this work, carp sequences were collected and built into contigs. Human-carp functional homolog relationships were derived via zebrafish using a new Conditional Stepped Reciprocal Best Hit (CSRBH) protocol. Data sources including publications, Gene Ontology and cDNA libraries were then used to predict the identity of known or potential angiogenic genes. Finally, re-analyses of cold carp microarray data identified carp genes up-regulated in response to low temperatures in heart and muscle.</p> <p>Results</p> <p>The CSRBH approach outperformed all other methods and attained 8,726 carp to human functional homolog relationships for 16,650 contiguous sequences. This represented 3,762 non-redundant genes and 908 of them were predicted to have a role in angiogenesis. The total number of up-regulated differentially expressed genes was 698 and 171 of them were putatively angiogenic. Of these, 5 genes representing the functional homologs NCL, RHOA, MMP9, GRN and MAPK1 are angiogenesis-related genes expressed in response to low temperature.</p> <p>Conclusion</p> <p>We show that CSRBH functional homologs relationships and re-analyses of gene expression data can be combined in a non-model species to predict genes of biological interest before a genome sequence is fully available. Programs to run these analyses locally are available from <url>http://www.cbrg.ox.ac.uk/~jherbert/</url>.</p
Noise auto-correlation spectroscopy with coherent Raman scattering
Ultrafast lasers have become one of the most powerful tools in coherent
nonlinear optical spectroscopy. Short pulses enable direct observation of fast
molecular dynamics, whereas broad spectral bandwidth offers ways of controlling
nonlinear optical processes by means of quantum interferences. Special care is
usually taken to preserve the coherence of laser pulses as it determines the
accuracy of a spectroscopic measurement. Here we present a new approach to
coherent Raman spectroscopy based on deliberately introduced noise, which
increases the spectral resolution, robustness and efficiency. We probe laser
induced molecular vibrations using a broadband laser pulse with intentionally
randomized amplitude and phase. The vibrational resonances result in and are
identified through the appearance of intensity correlations in the noisy
spectrum of coherently scattered photons. Spectral resolution is neither
limited by the pulse bandwidth, nor sensitive to the quality of the temporal
and spectral profile of the pulses. This is particularly attractive for the
applications in microscopy, biological imaging and remote sensing, where
dispersion and scattering properties of the medium often undermine the
applicability of ultrafast lasers. The proposed method combines the efficiency
and resolution of a coherent process with the robustness of incoherent light.
As we demonstrate here, it can be implemented by simply destroying the
coherence of a laser pulse, and without any elaborate temporal scanning or
spectral shaping commonly required by the frequency-resolved spectroscopic
methods with ultrashort pulses.Comment: To appear in Nature Physic
Patient-Specific Prosthetic Fingers by Remote Collaboration - A Case Study
The concealment of amputation through prosthesis usage can shield an amputee
from social stigma and help improve the emotional healing process especially at
the early stages of hand or finger loss. However, the traditional techniques in
prosthesis fabrication defy this as the patients need numerous visits to the
clinics for measurements, fitting and follow-ups. This paper presents a method
for constructing a prosthetic finger through online collaboration with the
designer. The main input from the amputee comes from the Computer Tomography
(CT) data in the region of the affected and the non-affected fingers. These
data are sent over the internet and the prosthesis is constructed using
visualization, computer-aided design and manufacturing tools. The finished
product is then shipped to the patient. A case study with a single patient
having an amputated ring finger at the proximal interphalangeal joint shows
that the proposed method has a potential to address the patient's psychosocial
concerns and minimize the exposure of the finger loss to the public.Comment: Open Access articl
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