635 research outputs found
Bimaximal Neutrino Mixing in a Zee-type Model with Badly Broken Flavor Symmetry
A Zee-type neutrino mass matrix model with a badly broken horizontal symmetry
SU(3)_H is investigated. By putting a simple ansatz on the symmetry breaking
effects of SU(3)_H for transition matrix elements, it is demonstrated that the
model can give a nearly bimaximal neutrino mixing with the ratio ,
which are in excellent agreement with the observed data. In the near future,
the lepton-number violating decay will be observed.Comment: 10 pages, no figures, a comment adde
SDN next generation integrated architecture for HEP and global science
I describe a software-defined global system under development by Caltech and partner network teams in support of the LHC and other major science programs that coordinates workflows among hundreds of multi-petabyte data stores and petascale computing facilities interlinked by 100 Gbps networks, and the Exascale systems needed by the next decade
Changing from face-to-face to virtual meetings due to the COVID-19 pandemic: Protocol for a mixed-methods study exploring the impact on cancer multidisciplinary team (MDT) meetings
INTRODUCTION:
In the UK, the National Cancer Plan (2000) requires every cancer patient’s care to be reviewed by a multidisciplinary team (MDT). Since the introduction of these guidelines, MDTs have faced escalating demands with increasing numbers and complexity of cases. The COVID-19 pandemic has presented MDTs with the challenge of running MDT meetings virtually rather than face-to-face.
This study aims to explore how the change from face-to-face to virtual MDT meetings during the COVID-19 pandemic may have impacted the effectiveness of decision-making in cancer MDT meetings and to make recommendations to improve future cancer MDT working based on the findings.
METHODS AND ANALYSIS:
A mixed-methods study with three parallel phases:
Semistructured remote qualitative interviews with ≤40 cancer MDT members.
A national cross-sectional online survey of cancer MDT members in England, using a validated questionnaire with both multiple-choice and free-text questions.
Live observations of ≥6 virtual/hybrid cancer MDT meetings at four NHS Trusts.
Participants will be recruited from Cancer Alliances in England. Data collection tools have been developed in consultation with stakeholders, based on a conceptual framework devised from decision-making models and MDT guidelines. Quantitative data will be summarised descriptively, and χ2 tests run to explore associations. Qualitative data will be analysed using applied thematic analysis. Using a convergent design, mixed-methods data will be triangulated guided by the conceptual framework.
The study has been approved by NHS Research Ethics Committee (London—Hampstead) (22/HRA/0177). The results will be shared through peer-reviewed journals and academic conferences. A report summarising key findings will be used to develop a resource pack for MDTs to translate learnings from this study into improved effectiveness of virtual MDT meetings.
The study has been registered on the Open Science Framework (https://doi.org/10.17605/OSF.IO/D2NHW)
Broken R Parity Contributions to Flavor Changing Rates and CP Asymmetries in Fermion Pair Production at Leptonic Colliders
We examine the effects of the R parity odd renormalizable interactions on
flavor changing rates and CP violation asymmetries in the production of
fermion-antifermion pairs at leptonic colliders. The produced
fermions may be leptons, down-quarks or up-quarks, and the center of mass
energies may range from the Z-boson pole up to GeV. Off the Z-boson
pole, the flavor changing rates are controlled by tree level amplitudes and the
CP asymmetries by interference terms between tree and loop level amplitudes. At
the Z-boson pole, both observables involve loop amplitudes. The lepton number
violating interactions, associated with the coupling constants, \l_{ijk},
\l'_{ijk}, are only taken into account. The consideration of loop amplitudes
is restricted to the photon and Z-boson vertex corrections. We briefly review
flavor violation physics at colliders. We present numerical results using a
single, species and family independent, mass parameter, , for all the
scalar superpartners and considering simple assumptions for the family
dependence of the R parity odd coupling constants.Comment: Latex File. 23 pages. 4 postscript figures. 1 table. Revised version
with new results and several corrections in numerical result
Recommended from our members
Destabilisation and modification of Tollmien-Schlichting disturbances by a three-dimensional surface indentation
We consider the influence of a smooth three-dimensional (3-D) indentation on the instability of an incompressible boundary layer by linear and nonlinear analyses. The numerical work was complemented by an experimental study to investigate indentations of approximately δ99 and δ99 width at depths of 45%, 52% and 60% of δ99 where δ99 indicates 99% boundary layer thickness. For these indentations a separation bubble confined within the indentation arises. Upstream of the indentation, spanwise-uniform Tollmien-Schlichting (TS) waves are assumed to exist, with the objective to investigate how the 3-D surface indentation modifies the 2-D TS disturbance. Numerical corroboration against experimental data reveals good quantitative agreement. Comparing the structure of the 3-D separation bubble to that created by a purely 2-D indentation, there are a number of topological changes particularly in the case of the widest indentation; more rapid amplification and modification of the upstream TS waves along the symmetry plane of the indentation is observed. For the shortest indentations, beyond a certain depth there are then no distinct topological changes of the separation bubbles and hence on flow instability. The destabilising mechanism is found to be due to the confined separation bubble and is attributed to the inflectional instability of the separated shear layer. Finally for the widest width indentation investigated , results of the linear analysis are compared with direct numerical simulations. A comparison with the traditional criteria of using -factors to assess instability of properly 3-D disturbances reveals that a general indication of flow destabilisation and development of strongly nonlinear behaviour is indicated as values are attained. However -factors, based on linear models, can only be used to provide indications and severity of the destabilisation, since the process of disturbance breakdown to turbulence is inherently nonlinear and dependent on the magnitude and scope of the initial forcing
Potential of deep learning segmentation for the extraction of archaeological features from historical map series
Historical maps present a unique depiction of past landscapes, providing evidence for a wide range of information such as settlement distribution, past land use, natural resources, transport networks, toponymy and other natural and cultural data within an explicitly spatial context. Maps produced before the expansion of large‐scale mechanized agriculture reflect a landscape that is lost today. Of particular interest to us is the great quantity of archaeologically relevant information that these maps recorded, both deliberately and incidentally. Despite the importance of the information they contain, researchers have only recently begun to automatically digitize and extract data from such maps as coherent information, rather than manually examine a raster image. However, these new approaches have focused on specific types of information that cannot be used directly for archaeological or heritage purposes. This paper provides a proof of concept of the application of deep learning techniques to extract archaeological information from historical maps in an automated manner. Early twentieth century colonial map series have been chosen, as they provide enough time depth to avoid many recent large‐scale landscape modifications and cover very large areas (comprising several countries). The use of common symbology and conventions enhance the applicability of the method. The results show deep learning to be an efficient tool for the recovery of georeferenced, archaeologically relevant information that is represented as conventional signs, line‐drawings and text in historical maps. The method can provide excellent results when an adequate training dataset has been gathered and is therefore at its best when applied to the large map series that can supply such information. The deep learning approaches described here open up the possibility to map sites and features across entire map series much more quickly and coherently than other available methods, opening up the potential to reconstruct archaeological landscapes at continental scales
How to Cost the Implementation of Major System Change for Economic Evaluations: Case Study Using Reconfigurations of Specialist Cancer Surgery in Part of London, England.
BACKGROUND: Studies have been published regarding the impact of major system change (MSC) on care quality and outcomes, but few evaluate implementation costs or include them in cost-effectiveness analysis (CEA). This is despite large potential costs of MSC: change planning, purchasing or repurposing assets, and staff time. Implementation costs can influence implementation decisions. We describe our framework and principles for costing MSC implementation and illustrate them using a case study. METHODS: We outlined MSC implementation stages and identified components, using a framework conceived during our work on MSC in stroke services. We present a case study of MSC of specialist surgery services for prostate, bladder, renal and oesophagogastric cancers, focusing on North Central and North East London and West Essex. Health economists collaborated with qualitative researchers, clinicians and managers, identifying key reconfiguration stages and expenditures. Data sources (n = approximately 100) included meeting minutes, interviews, and business cases. National Health Service (NHS) finance and service managers and clinicians were consulted. Using bottom-up costing, items were identified, and unit costs based on salaries, asset costs and consultancy fees assigned. Itemised costs were adjusted and summed. RESULTS: Cost components included options appraisal, bidding process, external review; stakeholder engagement events; planning/monitoring boards/meetings; and making the change: new assets, facilities, posts. Other considerations included hospital tariff changes; costs to patients; patient population; and lifetime of changes. Using the framework facilitated data identification and collection. The total adjusted implementation cost was estimated at £7.2 million, broken down as replacing robots (£4.0 million), consultancy fees (£1.9 million), staff time costs (£1.1 million) and other costs (£0.2 million). CONCLUSIONS: These principles can be used by funders, service providers and commissioners planning MSC and researchers evaluating MSC. Health economists should be involved early, alongside qualitative and health-service colleagues, as retrospective capture risks information loss. These analyses are challenging; many cost factors are difficult to identify, access and measure, and assumptions regarding lifetime of the changes are important. Including implementation costs in CEA might make MSC appear less cost effective, influencing future decisions. Future work will incorporate this implementation cost into the full CEAs of the London Cancer MSC. TRIAL REGISTRATION: Not applicable
Securing recruitment and obtaining informed consent in minority ethnic groups in the UK
Background: Previous health research has often explicitly excluded individuals from minority
ethnic backgrounds due to perceived cultural and communication difficulties, including studies
where there might be language/literacy problems in obtaining informed consent. This study
addressed these difficulties by developing audio-recorded methods of obtaining informed consent
and recording data. This report outlines 1) our experiences with securing recruitment to a
qualitative study investigating alternative methods of data collection, and 2) the development of a
standardised process for obtaining informed consent from individuals from minority ethnic
backgrounds whose main language does not have an agreed written form.
Methods: Two researchers from South Asian backgrounds recruited adults with Type 2 diabetes
whose main language was spoken and not written, to attend a series of focus groups. A screening
tool was used at recruitment in order to assess literacy skills in potential participants. Informed
consent was obtained using audio-recordings of the patient information and recording patients'
verbal consent. Participants' perceptions of this method of obtaining consent were recorded.
Results: Recruitment rates were improved by using telephone compared to face-to-face methods.
The screening tool was found to be acceptable by all potential participants. Audio-recorded
methods of obtaining informed consent were easy to implement and accepted by all participants.
Attrition rates differed according to ethnic group. Snowballing techniques only partly improved
participation rates.
Conclusion: Audio-recorded methods of obtaining informed consent are an acceptable
alternative to written consent in study populations where literacy skills are variable. Further
exploration of issues relating to attrition is required, and a range of methods may be necessary in
order to maximise response and participation
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