1,095 research outputs found
The Probability Density of the Higgs Boson Mass
The LEP Collaborations have reported a small excess of events in their
combined Higgs boson analysis at center of mass energies up to about 208 GeV.
In this communication, I present the result of a calculation of the probability
distribution function of the Higgs boson mass which can be rigorously obtained
if the validity of the Standard Model is assumed. It arises from the
combination of the most recent set of precision electroweak data and the
current results of the Higgs searches at LEP 2.Comment: 3 pages, 2 figure
A simple formula for pooling knowledge about a quantum system
When various observers obtain information in an independent fashion about a
classical system, there is a simple rule which allows them to pool their
knowledge, and this requires only the states-of-knowledge of the respective
observers. Here we derive an equivalent quantum formula. While its realm of
applicability is necessarily more limited, it does apply to a large class of
measurements, and we show explicitly for a single qubit that it satisfies the
intuitive notions of what it means to pool knowledge about a quantum system.
This analysis also provides a physical interpretation for the trace of the
product of two density matrices.Comment: 5 pages, Revtex
The Golden Channel at a Neutrino Factory revisited: improved sensitivities from a Magnetised Iron Neutrino Detector
This paper describes the performance and sensitivity to neutrino mixing
parameters of a Magnetised Iron Neutrino Detector (MIND) at a Neutrino Factory
with a neutrino beam created from the decay of 10 GeV muons. Specifically, it
is concerned with the ability of such a detector to detect muons of the
opposite sign to those stored (wrong-sign muons) while suppressing
contamination of the signal from the interactions of other neutrino species in
the beam. A new more realistic simulation and analysis, which improves the
efficiency of this detector at low energies, has been developed using the GENIE
neutrino event generator and the GEANT4 simulation toolkit. Low energy neutrino
events down to 1 GeV were selected, while reducing backgrounds to the
level. Signal efficiency plateaus of ~60% for and ~70% for
events were achieved starting at ~5 GeV. Contamination from the
oscillation channel was studied for the first
time and was found to be at the level between 1% and 4%. Full response matrices
are supplied for all the signal and background channels from 1 GeV to 10 GeV.
The sensitivity of an experiment involving a MIND detector of 100 ktonnes at
2000 km from the Neutrino Factory is calculated for the case of . For this value of , the accuracy in the
measurement of the CP violating phase is estimated to be , depending on the value of ,
the CP coverage at is 85% and the mass hierarchy would be determined
with better than level for all values of
Toroidal magnetized iron neutrino detector for a neutrino factory
A neutrino factory has unparalleled physics reach for the discovery and measurement of CP violation in the neutrino sector. A far detector for a neutrino factory must have good charge identification with excellent background rejection and a large mass. An elegant solution is to construct a magnetized iron neutrino detector (MIND) along the lines of MINOS, where iron plates provide a toroidal magnetic field and scintillator planes provide 3D space points. In this paper, the current status of a simulation of a toroidal MIND for a neutrino factory is discussed in light of the recent measurements of large θ13. The response and performance using the 10 GeV neutrino factory configuration are presented. It is shown that this setup has equivalent δCP reach to a MIND with a dipole field and is sensitive to the discovery of CP violation over 85% of the values of δCP
Forward Flux Sampling-type schemes for simulating rare events: Efficiency analysis
We analyse the efficiency of several simulation methods which we have
recently proposed for calculating rate constants for rare events in stochastic
dynamical systems, in or out of equilibrium. We derive analytical expressions
for the computational cost of using these methods, and for the statistical
error in the final estimate of the rate constant, for a given computational
cost. These expressions can be used to determine which method to use for a
given problem, to optimize the choice of parameters, and to evaluate the
significance of the results obtained. We apply the expressions to the
two-dimensional non-equilibrium rare event problem proposed by Maier and Stein.
For this problem, our analysis gives accurate quantitative predictions for the
computational efficiency of the three methods.Comment: 19 pages, 13 figure
What is the healthcare utilisation and out-of-pocket expenditure associated with osteoarthritis? A cross-sectional study.
OBJECTIVE: To examine the use and out-of-pocket expenses resulting from consultations, products and practices across conventional, self-care, and complementary medicine (CM) treatments for osteoarthritis (OA) among Australian women. DESIGN, SETTING AND PARTICIPANTS: A cross-sectional survey of 800 women from the 45 and Up Study who had reported a clinical diagnosis of OA. OUTCOME MEASURES: Women's use of conventional, CM and self-prescribed treatments for OA and the associated out-of-pocket cost. RESULTS: Completed questionnaires were returned by 403 women (50.4%). Their average time since the first diagnosis of OA was 15.4 years, and self-rated severity of OA was 5.1 (out of 10) over the past 12 months. During the previous year, 67.0% of the women consulted a doctor, 39.2% consulted an allied health practitioner and 34.7% consulted a CM practitioner for their OA. Some women (19%) consulted with practitioner(s) from all three practitioner groups, 27% consulted with practitioner(s) from two of the three practitioner groups, while 6% consulted with a CM practitioner only. Women with a greater time since diagnosis had more consultations, as did women who rated their OA as more severe. Women's average combined out-of-pocket expenditure for OA-related healthcare consultations, prescription medications, products, and practices was 873 million per annum. CONCLUSIONS: Australian women with OA use a range of conventional and CM consultations, self-care, products and practices to manage their condition, incurring significant out-of-pocket expenses. Given the high individual and societal burden of OA, there is a need for further research into the concurrent use of different healthcare resources with a view to providing safe, cost-effective management of OA across the healthcare system and the wider community
Fitting in a complex chi^2 landscape using an optimized hypersurface sampling
Fitting a data set with a parametrized model can be seen geometrically as
finding the global minimum of the chi^2 hypersurface, depending on a set of
parameters {P_i}. This is usually done using the Levenberg-Marquardt algorithm.
The main drawback of this algorithm is that despite of its fast convergence, it
can get stuck if the parameters are not initialized close to the final
solution. We propose a modification of the Metropolis algorithm introducing a
parameter step tuning that optimizes the sampling of parameter space. The
ability of the parameter tuning algorithm together with simulated annealing to
find the global chi^2 hypersurface minimum, jumping across chi^2{P_i} barriers
when necessary, is demonstrated with synthetic functions and with real data
Potential role for clinical calibration to increase engagement with and application of home telemonitoring: a report from the HeartCycle programme
Aims: There is a need for alternative strategies that might avoid recurrent admissions in patients with heart failure. Home Telemonitoring (HTM) to monitor patientâs symptoms from a distance may be useful. This study attempts to assess changes in HTM vital signs in response to daily life activities (variations in medication, salt intake, exercise and stress) and to stablish which variations affect weight, blood pressure (BP) and heart rate (HR). Methods and results: We assessed 76 patients with heart failure (mean age 76 Âą 10.8 years, 75% male, mainly in NYHA class II/III and from ischaemic etiology cause). Patients were given a calendar of interventions scheduling activities approximately twice-a-week before measuring their vital signs. Eating salty food or a large meal were the activities that had a significant impact on weight gain (+0.3 kg; p<0.001 and p=0.006, respectively). Exercise and skipping a dose of medication other than diuretics increased heart rate (+3 bpm, p=0.001 and almost +2 bpm, p=0.016, respectively). Conclusions: Our HTM system was able to detect small changes in vital signs related to these activities. Further studies should assess if providing such a schedule of activities might be useful for patient education and could improve long-term adherence to recommended lifestyle changes
North-central Nigerian womenâs experiences of obstetric fistula risk factors and their perceived treatment services: An interpretive description
Background An obstetric fistula also known as vesico vaginal fistula (VVF), or recto-vaginal fistula (RVF) is an abnormal opening between the urogenital tract and intestinal tract caused by prolonged obstructed labour; when the head of the baby presses on the soft tissues in the pelvis leading to loss of blood flow to the womenâs bladder, vagina, and rectum. This can cause necrosis of the soft tissues resulting in debilitating fistula formations.
Aim This study aimed to uncover North-central Nigerian womenâs experiences of obstetric fistula and their perceived treatment services.
Design Qualitative, interpretive descriptive methodology underpinned by symbolic interactionism involving face-to-face semi-structured interviews was used to explore North-central Nigerian womenâs experiences of obstetric fistula and their perceived treatment services.
Sample A purposive sample of 15 women who had experienced obstetric fistula at a repair Centre in North-central Nigeria were eligible.
Results Four themes emerged from North-central Nigerian womenâs experiences of obstetric fistula and their perceived treatment services i) I was left alone in the room ii) Waiting for the one vehicle in the village iii) I never knew about labour until that very day iv) and We kept following the native doctors and sorcerers.
Conclusion The findings from this study highlighted the depth of womenâs experiences from the devastating complication of childbirth injury in North-central Nigeria. Analysis of insights from womenâs voices directly affected by obstetric fistula demonstrated that in their views and experiences the themes identified were majorly responsible for their fistula status. Thus women need to raise their collective voices to resist oppressive harmful traditions and demand empowerment opportunities that will improve their social status. Government should improve primary healthcare facilities, train more midwives and subsidise maternal care for antenatal education and birth services spending for childbirth women may result in improved childbirth experiences for women in rural and urban communities.
Tweetable Abstract Reproductive women call for increased accessibility to healthcare services and the provision of more midwives to mitigate obstetric fistula in North-central Nigerian communities
A mixed-method process evaluation of an East Midlands county summer 2021 holiday activities and food programme highlighting the views of programme co-ordinators, providers, and parents
BACKGROUND: The Holiday Activities and Food (HAF) Programme is a UK Government initiative created to alleviate food insecurity and promote health and well-being among children and their families, who are eligible for Free School Meals (FSM), during the school holidays. This process evaluation investigated factors that facilitated and acted as a barrier to the delivery of the HAF Programme from the perspectives of key stakeholders (Co-ordinators, Providers, and Parents) involved in the HAF Programme across an East Midlands county. METHODS: This evaluation utilized a mixed-methods approach, incorporating focus groups and online surveys to gain rich, multifaceted data. The focus groups were analyzed using a hybrid inductive-deductive thematic analysis and the online surveys were analyzed using mixed-methods approach due to the variation in question type (i.e., quantitative, Likert scale and open response) to align themes to the Government Aims and Standards of the HAF Programme. FINDINGS: The stakeholders highlighted several factors that facilitated and acted as a barrier to the delivery of the HAF Programme. Facilitating factors included existing and maintaining relationships between Co-ordinators, Providers, and facilities/schools/communities as this improved communication and attendance. Additionally, transport provision for those attending the Programme helped overcome barriers to attendance. The primary barrier of the Programme was the late awarding of the Programme contract as this limited the time available to prepare and organize the Programme. This in turn, had several âknock onâ effects that created more barriers and resulted in some of the Government Aims and Standards not being met such as, nutrition education for children and parents. Despite the challenges faced, Co-ordinators and Providers were able to deliver the Programme and positively impact upon the children and their families that attended the Programme. CONCLUSION: Following the facilitators and barriers that were highlighted in this evaluation, several recommendations have been made to enhance the delivery of the HAF Programme and ensure Government Aims and Standards, to improve children and family's health and well-being, are attained
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