2,748 research outputs found
Fibre optic sensors for high speed hypervelocity impact studies and low velocity drop tests
The initial aim of this project was to develop a non-contact fibre optic based displacement sensor to operate in the harsh environment of a 'Light Gas Gun' (LGG), which can 'fire' small particles at velocities ranging from 1-8.4 km/s. The LGG is used extensively for research in aerospace to analyze the effects of high speed impacts on materials. Ideally the measurement should be made close to the centre of the impact to minimise corruption of the data from edge effects and survive the impact. A further requirement is that it should operate at a stand-off distance of ~ 8cm. For these reasons we chose to develop a pseudo con-focal intensity sensor, which demonstrated resolution comparable with conventional PVDF sensors combined with high survivability and low cost. A second sensor was developed based on 'Fibre Bragg Gratings' (FBG) which although requiring contact with the target the low weight and very small contact area had minimal effect on the dynamics of the target. The FBG was mounted either on the surface of the target or tangentially between a fixed location. The output signals from the FBG were interrogated in time by a new method. Measurements were made on composite and aluminium plates in the LGG and on low speed drop tests. The particle momentum for the drop tests was chosen to be similar to that of the particles used in the LGG
Targeted anthelmintic treatment of parasitic gastroenteritis in first grazing season dairy calves using daily live weight gain as an indicator
Control of parasitic gastroenteritis in cattle is typically based on group treatments with anthelmintics, complemented by grazing management, where feasible. However, the almost inevitable evolution of resistance in parasitic nematodes to anthelmintics over time necessitates a reappraisal of their use in order to reduce selection pressure. One such approach is targeted selective treatment (TST), in which only individual animals that will most benefit are treated, rather than whole groups of at-risk cattle. This study was designed to assess the feasibility of implementing TST on three commercial farms, two of which were organic. A total of 104 first-grazing season (FGS), weaned dairy calves were enrolled in the study; each was weighed at monthly intervals from the start of the grazing season using scales or weigh-bands. At the same time dung and blood samples were collected in order to measure faecal egg counts (FEC) and plasma pepsinogen, respectively. A pre-determined threshhold weight gain of 0.75 kg/day was used to determine those animals that would be treated; the anthelmintic used was eprinomectin. No individual animal received more than one treatment during the grazing season and all treatments were given in July or August; five animals were not treated at all because their growth rates consistently exceeded the threshold. Mean daily live weight gain over the entire grazing season ranged between 0.69 and 0.82 kg/day on the three farms. Neither FEC nor pepsinogen values were significantly associated with live weight gain. Implementation of TST at farm level requires regular (monthly) handling of the animals and the use of weigh scales or tape, but can be integrated into farm management practices. This study has shown that acceptable growth rates can be achieved in FGS cattle with modest levels of treatment and correspondingly less exposure of their nematode populations to anthelmintics, which should mitigate selection pressure for resistance by increasing the size of the refugia in both hosts and pasture
Two Particle States and the -matrix Elements in Multi-channel Scattering
Using a quantum mechanical model, the exact energy eigenstates for
two-particle two-channel scattering are studied in a cubic box with periodic
boundary conditions in all three directions. A relation between the exact
energy eigenvalue in the box and the two-channel -matrix elements in the
continuum is obtained. This result can be viewed as a generalization of the
well-known L\"uscher's formula which establishes a similar relation in elastic
scattering.Comment: 18 pages, no figures. minor changes compared with previous versio
Multilateral inversion of A_r, C_r and D_r basic hypergeometric series
In [Electron. J. Combin. 10 (2003), #R10], the author presented a new basic
hypergeometric matrix inverse with applications to bilateral basic
hypergeometric series. This matrix inversion result was directly extracted from
an instance of Bailey's very-well-poised 6-psi-6 summation theorem, and
involves two infinite matrices which are not lower-triangular. The present
paper features three different multivariable generalizations of the above
result. These are extracted from Gustafson's A_r and C_r extensions and of the
author's recent A_r extension of Bailey's 6-psi-6 summation formula. By
combining these new multidimensional matrix inverses with A_r and D_r
extensions of Jackson's 8-phi-7 summation theorem three balanced
very-well-poised 8-psi-8 summation theorems associated with the root systems
A_r and C_r are derived.Comment: 24 page
Service Evaluation of 'Living Well with the Impact of Cancer' Courses
The aim of the Penny Brohn Cancer Care Living Well Service Evaluation was to measure the level of benefit that participants were receiving from the Penny Brohn Cancer Care(PBCC)Living Well course and to inform current and future service provision at PBCC.
The Penny Brohn Whole Person Approach model(PB-WPA model), which underpins the Living Well course, was designed to support the ‘whole person’ and the course was
intended to meet the needs of people with cancer, as identified by the National Cancer Survivorship Initiative (NCSI).
The combined qualitative and quantitative results of the Living Well Service Evaluation have demonstrated, very clearly at times, that participants were highly satisfied with the course. The immediate benefit of attending was measurable, in terms of improved health related quality of life (HRQoL) and improved MYCaW (Measure yourself Concerns and Wellbeing) concerns and wellbeing.
The evaluation results show that the Living Well course experience enabled the majority of participants to regain control over many aspects of their life, and to start
taking responsibility for their health. The following aspects of the course were identified as the most helpful:
-Specific units of ‘education and explanation’ about cancer and why healthy lifestyle changes to areas such as diet, exercise and relaxation are beneficial
-Advice and education from medical doctors
-The opportunity to share experiences with other participants
For some, this empowerment led to long-term changes in exercise, food consumption,use of self-help techniques and the ability to communicate more freely and openly with family, friends and medical professionals. These improvements were reflected in the 12 month outcome data, where a sustained improvement in HRQoL and MYCaW concerns
was reported by many clients.
Such patient reported outcome measures (PROMs) are limited in what they can measure, thus qualitative data were also collected to ensure that participants were able
to share their experiences (positive or negative) of the Living Well course, and their subsequent experiences of applying the education and techniques learnt on the
course.
A picture emerged that identified difficulties in sustaining lifestyle changes at around the 3-6 month follow-up. Participants who returned to PBCC within the 12 month follow-up period, however, were more likely to benefit by reporting a greater improvement in HRQoL and MYCaW scores, plus an improved understanding of how to
make and maintain healthy lifestyle changes to suit their individual circumstances.
In regards to the current NCSI priorities, it is hoped that the data reported in this evaluation go some way to informing the following:
-Information and support from the point of diagnosis
-Managing the consequences of treatment
-Promoting recovery
-Sustaining recovery
-Supporting people with active and advanced disease
-Improving survivorship intelligence
Finally, this report demonstrates how a patient-centred model of support can be effectively evaluated to provide relevant, practical and evidence-based information to
commissioners.
Participant satisfaction:
Participants were very satisfied with the course content, course delivery and resources provided which often exceeded their needs and expectations.
Participant outcomes:
The PB-WPA model successfully encompassed and supported all the types of concerns participants arrived with.
The most frequently reported participant concerns were psychological and emotional,about their wellbeing and about their physical health. On average, participants experienced statistically and clinically significant
improvements in their MYCaW concern and wellbeing scores, and total HRQoL scores,which remained improved over the 12 month follow-up. The aspects of HRQoL that were most likely to improve after attending the Living Well
course were spiritual, emotional and functional wellbeing. Supporters had their own profile of concerns, namely psychological and emotional,supporter specific concerns and practical concerns. Concerns were as severely rated as those from participants with a diagnosis of cancer and also showed statistically
significant average improvements throughout the 12 month follow-up.
The small group of participants with metastatic disease reported significant improvements in their MYCaW concern scores, in line with the whole evaluation group,and a significantly greater improvement in HRQoL over 12 months compared to participants with primary cancer.Participants who returned for more support from PBCC were in more need of support than those who did not return. They were more likely to have poorer HRQoL at baseline
and rate their concerns more severely.
Participants who returned to PBCC experienced more improvement in HRQoL that was likely to be clinically significant. These participants also had a greater degree of improvement in their MYCaW concerns, compared to non-returners. Over half of the participants experienced new concerns over the 12 month follow-up period. Concerns were most frequently associated with psychological and emotional
and physical issues. Furthermore, at 12 months, participants were still experiencing arange of health issues
The Responsiveness, Content Validity, and Convergent Validity of the Measure Yourself Concerns and Wellbeing (MYCaW) Patient-Reported Outcome Measure
Objective
Measure Yourself Concerns and Wellbeing (MYCaW) is a patient-centred questionnaire that allows cancer patients to identify and quantify the severity of their ‘Concerns’ and Wellbeing, as opposed to using a pre-determined list. MYCaW administration is brief and aids in prioritising treatment approaches. Our goal was to assess the convergent validity and responsiveness of MYCaW scores over time, the generalisability of the existing qualitative coding framework in different complementary and integrative healthcare settings and content validity.
Methods
Baseline and 6-week follow-up data (n=82) from MYCaW and FACIT-SpEx questionnaires were collected for a service evaluation of the ‘Living Well With The Impact of Cancer’ course at Penny Brohn Cancer Care. MYCaW construct validity was determined using Spearman's Rank Correlation test, and responsiveness indices assessed score changes over time. The existing qualitative coding framework was reviewed using a new dataset (n=158) and coverage of concern categories compared to items of existing outcome measures.
Results
Good correlation between MYCaW and FACIT-SpEx score changes were achieved (r= -0.57, p≥0.01). MYCaW Profile and Concern scores were highly responsive to change: SRM=1.02 and 1.08; effect size=1.26 and 1.22. MYCaW change scores showed the anticipated gradient of change according to clinically relevant degrees of change. Categories including ‘Spirituality’, ‘weight change’ and ‘practical concerns’ were added to the coding framework to improve generalisability.
Conclusions
MYCaW scores were highly responsive to change, allowing personalized patient outcomes to be quantified; the qualitative coding framework is generalisable across different oncology settings and has broader coverage of patient-identified concerns compared with existing cancer-related patient-reported outcome measures
Using a whole person approach to support people with cancer: a longitudinal, mixed methods service evaluation
Introduction: Improved models of care are needed to meet all the support needs of people with cancer, which encompass psychological, emotional, physical, spiritual, sexual, occupational, social and existential needs. The aim of this paper is to (1) evaluate short and long-term impacts of using a whole person approach to support people with cancer on the Living Well with the Impact of Cancer Course (LWC); (2) use these data to inform strategic decisions about future service provision at Penny Brohn UK.
Methods: Longitudinal mixed-methods service evaluation (n=135). Data collected included health related quality of life (HRQoL) (FACIT-SpEx); Concerns (types and severity - MYCaW); lifestyle behaviour (bespoke questionnaire) and participants’ experiences over 12 months post course.
Results: Statistically and clinically significant improvements from baseline - 12 months in severity of MYCaW Concerns (n=64; p<0.000) and mean total HRQoL (n=66; p<0.000). The majority of MYCaW concerns were ‘psychological and emotional’ and about participants’ wellbeing. Spiritual, emotional and functional wellbeing contributed most to HRQoL improvements at 12 months. Barriers to maintaining healthy lifestyle changes included lack of support from family and friends, time constraints, and returning to work. 3-6 months post-course was identified as the time when more support was most likely to be needed.
Conclusions: Using a whole person approach for the LWC enabled the needs of participants to be met, and statistically and clinically significant improvements in HRQoL and MYCaW Concerns were reported. Qualitative data analysis explored how experiencing whole person support enabled participants to make and sustain healthy lifestyle changes associated with improved survivorship. Barriers experienced to making health behaviour change were also identified. These data then informed wider and more person-centred clinical provision to increase the maintenance of positive long-term behaviour changes. Comparison of whole person approaches to cancer treatment and support and standard care are now urgently needed
A Nonlinear Force-Free Magnetic Field Approximation Suitable for Fast Forward-Fitting to Coronal Loops. I. Theory
We derive an analytical approximation of nonlinear force-free magnetic field
solutions (NLFFF) that can efficiently be used for fast forward-fitting to
solar magnetic data, constrained either by observed line-of-sight magnetograms
and stereoscopically triangulated coronal loops, or by 3D vector-magnetograph
data. The derived NLFFF solutions provide the magnetic field components
, , , the force-free parameter
, the electric current density , and are
accurate to second-order (of the nonlinear force-free -parameter). The
explicit expressions of a force-free field can easily be applied to modeling or
forward-fitting of many coronal phenomena.Comment: Solar Physics (in press), 26 pages, 11 figure
Transverse self-fields within an electron bunch moving in an arc of a circle
As a consequence of motions driven by external forces, self-fields (which are
different from the static case) originate within an electron bunch. In the case
of magnetic external forces acting on an ultrarelativistic beam, the
longitudinal self-interactions are responsible for CSR (Coherent Synchrotron
Radiation)-related phenomena, which have been studied extensively. On the other
hand, transverse self-interactions are present too. At the time being, existing
theoretical analysis of transverse self-forces deal with the case of a bunch
moving along a circular orbit only, without considering the situation of a
bending magnet with a finite length. In this paper we propose an
electrodynamical analysis of transverse self-fields which originate, at the
position of a test particle, from an ultrarelativistic electron bunch moving in
an arc of a circle. The problem will be first addressed within a two-particle
system. We then extend our consideration to a line bunch with a stepped density
distribution, a situation which can be easily generalized to the case of an
arbitrary density distribution. Our approach turns out to be also useful in
order to get a better insight in the physics involved in the case of simple
circular motion and in order to address the well known issue of the partial
compensation of transverse self-force.Comment: 23 pages, 14 figure
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