2,901 research outputs found
Introduction to the issue on novel and specialty fibers
No full textThe fiber optical communication revolution has been fueled by well publicized and relentless improvements of transmission fiber. Since the demonstration of the first low-loss optical fiber in 1972, there has been a continual stream of technology improvements designed to reduce impairments due to propagation loss and pulse dispersion. This steam of fiber technology has led the industry from multimode fiber operated at 800 nm, to standard single-mode fiber used at 1310 nm, then on to transmission fibers that now have attributes tuned for particular applications such as terrestrial or submarine transmission. There is every reason to believe that advances in technology will continue at the accelerating pace we have seen in the past decade, adding to the family of available transmission fibers. The special issue is dedicated to the increasing family of specialty fibers, and includes exciting papers on fibers for gratings and a unique amplification fiber. Fibers for specialized transmission spanning a broad range of applications are also described in three important articles. As is appreciated by all optical scientists, progress can be made only as quickly as one can improve measurement capabilities, so the issue includes two excellent papers dealing with the important measurement of chromatic dispersion.We hope that you enjoy the papers of this issue as much as we the editors have enjoyed reading and reviewing them
Investigation of head repositioning accuracy as a measure of cervicocephalic kinaesthetic sensibility in patients with chronic neck pain
No full textThe majority of people can expect to experience neck pain in their lifetime and some will go on to
develop prolonged or repetitive episodes of neck pain or related symptoms. These persistent complaints
have become a major cause of disability around the world.
Although chronic ‘mechanical’ neck pain can be defined in clinical terms, the underlying pathology
remains unclear. Research has failed to demonstrate a consistent relationship between the presence of
neck pain and pathology such as degenerative changes. As such, there has been an increasing interest
in altered neuro-muscular-articular function in the pathogenesis of neck pain. Over the last 17 years, the
role of cervical proprioceptive (mechanoreceptive) dysfunction in the perpetuation of chronic neck pain
has received increasing attention from researchers and clinicians. This is commonly referred to as
cervicocephalic kinaesthetic sensibility (KS).
Cervicocephalic KS has generally been studied utilising head repositioning accuracy (HRA) tasks. At
the beginning of this study only seven reports had been published in the area. Following review of this
literature, several focused areas of interest were apparent for further study - 1) comparison of KS in
various patient subgroups (e.g., insidious onset vs ‘whiplash’); 2) development of more sophisticated
methods of measuring head movement and repositioning errors; 3) establishing the characteristics of the
tests such as method agreement and reliability; 4) comparison of the discriminative value of repositioning
tasks to both subjective ‘straight ahead’ (SSA) and to non-neutral set points within the cervical range of
motion (non-straight ahead or nSA).
Investigation 1 used a laser pointer method to study head repositioning errors in patients with chronic
neck pain of insidious onset. The results suggested that these patients with chronic neck pain show little
evidence of impaired cervicocephalic KS, when measured as HRA-SSA. The study also served to
highlight several difficulties with the laser pointer method of measurement and the relatively poor
knowledge of HRA in healthy subjects. Most previous studies used the mean of 10 repetitions for the
measurement but more recent studies utilised fewer repetitions. Although the laser pointer method is
simple, inexpensive and easy to use, the method involves a degree of experimenter bias and inaccuracy.
It also does not lend itself to concurrent evaluation of variables such as range of motion and speed of
head movement.
Investigations 2 & 3 focused on the development of the testing method and the introduction of the
Zebris CMS 70P ultrasound system for the recording of HRA-SSA, namely; method agreement between a
5 and 10 repetition measuring protocol; method agreement between the laser pointer and Zebris system;
the intra/inter-examiner reliability of measurement methods.
The Zebris system results suggested that the two methods of measurement agree sufficiently well for
the 5 repetition method to replace the 10 repetition method to obtain a mean HRA score and that both
could be used interchangeably. Further results suggested that the Zebris and laser pointer methods do
not agree sufficiently well to be used interchangeably. The test-retest reliability was comparable between
both methods suggesting that from this perspective, either could be used for measuring HRA-SSA. The
inter-rater test-retest reliability was comparable to the test-retest reliability suggesting that trained
examiners could be interchanged when carrying out repeated measurements.
Investigation 4, the final study in this thesis, investigated HRA with the Zebris system using the 5
repetition protocol in two groups of chronic neck pain patients; insidious onset and neck pain from a
‘whiplash’ injury. The results suggested that patients with chronic neck pain of both insidious onset and
from a ‘whiplash’ injury show little evidence of impaired cervicocephalic KS when measured using HRASSA
and nSA tests. These results conflict with previous studies
Despite numerous investigations over the last 17 years, a test that can be routinely applied in the
clinical setting for the purposes of diagnosis and treatment monitoring has not been established. Studies
to date suggest that an active HRA test to SSA/NHP that is established by the patient may have the
greatest discriminative value. Although HRA testing shows some promise in identifying deficits in
‘whiplash’ patients, it is unlikely that the KS tests identify specific subgroups of chronic neck pain patients.
There have been several contradictory studies which have shown considerable overlap between patient
and healthy groups. It is also unlikely that HRA tests represent a unique test of cervical proprioceptive
function (peripheral or central integration) and therefore provide a test exclusive to neck disorders
Paediatric neuro-oncology rehabilitation in the UK: care provider and service user perspectives
No full textObjective: The provision of rehabilitation services after childhood brain tumour has not been established, despite a recent parliamentary call for urgent action. This service evaluation aimed to determine what specialist paediatric neuro-oncology rehabilitation services were available across the UK at the time of the surveys, and whether the needs of patients and their families were being met.Design: Cross-sectional on-line surveys.Participants: Survey 1: Neuro-oncologist and nurse specialist members of the Children’s Cancer and Leukaemia Group (CCLG) at Children’s Principle Treatment Centres (PTCs) in the UK; Survey 2: Parents of paediatric neuro-oncology patients belonging to The Brain Tumour Charity (TBTC) Research Involvement Network (RIN). Results: 17 of the 20 (85%) PTCs in the UK and 2 teenagers and young adult cancer units responded to Survey 1, and 17 members of TBTC’s RIN responded to Survey 2. Access to inpatient and outpatient neuro-oncology rehabilitation services after treatment for a CNS tumour varied across regions in the UK. Service users in the RIN identified a need for an established neuro-oncology rehabilitation service for young people, a need for better communication across services and with families, and a need to fill gaps in multidisciplinary teams. Conclusions: The urgent need for specialist paediatric, teenage, and young adult neuro-oncology rehabilitation services in the UK is often unmet, particularly for outpatients. Where services are not provided for those children and young people disadvantaged by the diagnosis of a CNS tumour, in clear breach of current guidelines, remedial action needs to be taken to ensure appropriate and equal access
Poe's biopics : representations of the author in D.W. Griffith's Edgar Allen Poe and James Mcteigue's The raven
No full textLiterary biopics often reinforce romantic images regarding the creative process, emphasizing biographic and author-centered approaches to literature previously denounced by Roland Barthes (1977). Curiously, one of the most famous critics of such romantic conceptions, Edgar Allan Poe, has himself been a victim of this very same treatment, his literary production being taken as part and result of his controversial biography in a number of works. This article analyzes two biographical films, or biopics, about the renowned poet, D.W. Griffith’s Edgar Allen Poe (sic) (1909) and James McTeigue’s The Raven (2012). The analysis of these works indicates that both reinforce the merge of the artist’s life and oeuvre, as well as the blurring of borders between fact and fiction, author and character, high and mass culture, thus contributing to the characterization of the biopic as a fitting example of historiographic metafiction. (Hutcheon, 1988).Cinebiografias literárias frequentemente reforçam visões românticas quanto ao fazer artístico, reiterando a visão biografista e a centralidade do autor há muito denunciadas por Roland Barthes (1977). Curiosamente, um dos mais célebres críticos de tais concepções românticas, Edgar Allan Poe, viu-se vítima desse mesmo tratamento ao ter sua produção literária apropriada como parte e reflexo de sua controversa biografia em diversas obras. O presente artigo debruça-se sobre dois filmes biográficos, ou biopics, acerca do célebre poeta, Edgar Allen Poe (sic), de D.W. Griffith (1909), e O Corvo, de James McTeigue (2012). A análise das obras aponta que ambas reiteram a fusão entre vida e obrado artista, bem como o apagamento das fronteiras entre fato histórico e ficção, entre autor e personagem, alta cultura e cultura de massa, contribuindo para a caracterização do gênero biopic como um dos mais bem-acabados exemplos de metaficção historiográfica (Hutcheon, 1988)
Author Correction:A cattle graph genome incorporating global breed diversity
No full textThe original version of this Article omitted from the author list the 12th and 13th authors Dennis Muhanguzi and Wilson Amanyire, who are from the ‘School of Biosecurity, Biotechnology and Laboratory Sciences (SBLS), College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O Box 7062, Kampala, Uganda’. Consequently, the final sentence of the Author Contributions incorrectly read ‘D.W., P.T., E.A.J.C., C.E., E.T.O., E.R.A., A. Tijjani, K.M., A.F., B.R.F., A.Q., U.C. and P.W. provided samples and expertise for the studies’. This has been replaced with ‘D.W., P.T., W.A., D.M., E.A.J.C., C.E., E.T.O., E.R.A., A. Tijjani, K.M., A.F., B.R.F., A.Q., U.C. and P.W. provided samples and expertise for the studies’. This has been corrected in both the PDF and HTML versions of the Article
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
No full textIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
Analysis of ependymomas using comparative genomic hybridisation
No full textBackground and objectives Ependymomas are the third most common CNS tumours in childhood, and account for 9–12% of CNS neoplasms in all age groups. However, the prognosis for cases not completely excised is poor and the underlying biology of their development and progression is poorly understood. The few studies published to date have suggested that specific chromosomal abnormalities may be associated with the development of a significant proportion of these tumours. We setout to screen a large series of intracranial and spinal ependymomas for genetic imbalances, and to correlate these with histology and clinical behaviour.Methods Comparative genomic hybridisation (CGH) was used to detect chromosome imbalances on 86 ependymomas from 77 patients, of which 22 were children under 16, treated at one of three UK centres (Newcastle, Nottingham, Southampton). Cases were first analysed without reference to histology or clinical features, and were then divided up according to anatomical location, histology and age at presentation.Results Chromosomal imbalances were detected in tumours from 63/77 patients (82%). The majority involved entire chromosomes or chromosome arms, many showing patterns of gains suggestive of intermediate ploidy. Of previously reported abnormalities in ependymoma, the most frequent findings were gain of 1 q, seen in 13 cases (17%), and loss of 22 in 20 (26%). Whereas 1 q gain was seen mainly in posterior fossa tumours and was restricted to those with classic and anaplastic histology, loss of 22 was rarely observed in tumours from this location and their histology was predominantly classic or myxopapillary. In contrast to previous studies, loss of 6q was found in only 6 cases (8%) and in only one child. Out of 7 tumours biopsied at presentation and relapse, 4 revealed imbalances and 3 of these demonstrated progression of abnormalities at relapse.Conclusions Chromosomal imbalance is common in ependymoma and patterns of abnormality are emerging that are associated with histology or location. Further studies are needed to establish the prognostic significance of these abnormalities
Dynamic privilege management infrastructures utilising secure attribute exchange
No full textTechnologies which implement dynamic privilege management infrastructures will be crucial to the secure sharing of resources on the Grid, especially as the number of resources and participating sites increases. The DyVOSE project has successfully deployed Grid services secured with the PERMIS authorisation software implementing a static Privilege Management Infrastructure (PMI) model. The second stage of this project focuses on the extension of the current PERMIS infrastructure to include dynamic delegation of authority and cross-certification of institutional security policies. This paper describes the existing static PMI that has been used within the Grid Computing module as part of the advanced MSc at Glasgow University. We also outline an e-Science education use case that will be used to highlight how dynamic PMIs can be established using an extended version of PERMIS and utilising the Internet2 Shibboleth software to transfer user attributes and authentication tokens across institutional boundaries. This work addresses one of the key challenges in the Grid, supporting the dynamic establishment of secure Virtual Organisations (VOs)
- …
