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Models and tools to take into account evolutivity in learners profiles  [cached]
Stéphanie Jean-Daubias,Blandine Ginon,Marie Lefevre
STICEF , 2011,
Abstract: If the concept of learners profiles is now well known and treated in various ILE (Interactive Learning Environments), the taking into account of evolution in profiles do not benefit from the same advances. The subject of this paper is to define this notion and to show how it is taken into account en ILE researches. After a definition of the concept of progressive learners profiles illustrated with examples, we show how this concept changes the models of our project, notably PMDL profiles modeling language extended to PMDLe, to take into account the evolutivity of profiles.
Asking practical ethical questions about youth participation  [PDF]
Kim Knowles-Yanez
Les Ateliers de l’éthique , 2009,
Abstract: This paper is based on case study research conducted in an economically depressed, immigrant gateway neighborhood of Escondido, California. This study has been in progress since 2005 and involves working with children at the local middle school on rights-based community environmental action research projects in coordination with student facilitators in an upper-division uni- versity class titled “Children and the Environment.” This case study has suggested inquiry into the practical ethical dimensions of working with children, administrators, and university students on action research. Examples of the ethical questions which arose during this study include: how can continuity for the middle school children be achieved as different groups of university students move in and out of the project as they take and finish the “Children and the Environment” class, and is it ethical for the middle school children’s work to be facilitated by university students only freshly trained in the action research technique? This paper explores these and other ethical questions involving power, coercion, tension over expectations, and obligation and pro- vides direction for on-going ethical questions scholars should pursue in involving children in rights-based community environmental action research. Cet article se base sur une étude de cas menée dans un quartier immigrant défavorisé d’Escondido, Californie. Commencée en 2005, l’étude comporte le travail avec des enfants dans l’école secondaire locale autour des projets de recherche-action environnementale communautaire dans une approche de respect et de promotion des droits, avec la collaboration d’animateurs d’une université, inscrits dans le cours Les enfants et l’environnement . Cette étude de cas a soulevé des questions sur les dimensions éthiques du travail avec des enfants, le personnel scolaire et des étudiants universitaires dans la recherche-action. Comment peut-on atteindre une continuité pour l’enfant quand différents groupes d’étudiants universitaires rentrent et sortent du projet en prenant et en finissant le cours Les enfants et l’environnement ? Est-il éthique de charger l’animation des jeunes du secondaire aux étudiants universitaires qui n’ont été formés que très récemment à la recherche-action ? L’article explore ces questions et d’autres encore, concernant le pou- voir, la coercition, la tension au sujet des expectatives et l’obligation. Il offre un cadre pour les questions que les universitaires devraient se poser en travaillant avec des enfants dans la recherche-action environnementale communaut
Spallation Backgrounds in Super-Kamiokande Are Made in Muon-Induced Showers  [PDF]
Shirley Weishi Li,John F. Beacom
Physics , 2015,
Abstract: Crucial questions about solar and supernova neutrinos remain unanswered. Super-Kamiokande has the exposure needed for progress, but detector backgrounds are a limiting factor. A leading component is the beta decays of isotopes produced by cosmic-ray muons and their secondaries, which initiate nuclear spallation reactions. Cuts of events after and surrounding muon tracks reduce this spallation decay background by $\simeq 90\%$ (at a cost of $\simeq 20\%$ deadtime), but its rate at 6--18 MeV is still dominant. A better way to cut this background was suggested in a Super-Kamiokande paper [Bays {\it et al.}, Phys.~Rev.~D {\bf 85}, 052007 (2012)] on a search for the diffuse supernova neutrino background. They found that spallation decays above 16 MeV were preceded near the same location by a peak in the apparent Cherenkov light profile from the muon; a more aggressive cut was applied to a limited section of the muon track, leading to decreased background without increased deadtime. We put their empirical discovery on a firm theoretical foundation. We show that almost all spallation decay isotopes are produced by muon-induced showers and that these showers are rare enough and energetic enough to be identifiable. This is the first such demonstration for any detector. We detail how the physics of showers explains the peak in the muon Cherenkov light profile and other Super-K observations. Our results provide a physical basis for practical improvements in background rejection that will benefit multiple studies. For solar neutrinos, in particular, it should be possible to dramatically reduce backgrounds at energies as low as 6 MeV.
Cost Effectiveness Statistic: A Proposal To Take Into Account The Patient Stratification Factors  [PDF]
C. D'Urso
Statistics , 2013,
Abstract: The solution here proposed can be used to conduct economic analysis in randomized clinical trials. It is based on a statistical approach and aims at calculating a revised version of the incremental costeffective ratio (ICER) in order to take into account the key factors that can influence the choice of therapy causing confounding by indication. Let us take as an example a new therapy to treat cancer being compared to an existing therapy with effectiveness taken as time to death. A challenging problem is that the ICER is defined in terms of means over the entire treatment groups. It makes no provision for stratification by groups of patients with differing risk of death. For example, for a fair and unbiased analysis, one would desire to compare time to death in groups with similar life expectancy which would be impacted by factors such as age, gender, disease severity, etc. The method we decided to apply is borrowed by cluster analysis and aims at (i) discard any outliers in the set under analysis that may arise, (ii) identify groups (i.e. clusters) of patients with "similar" key factors.
MICE: The International Muon Ionization Cooling Experiment
Kaplan, D. M.;Long, K.
High Energy Physics - Phenomenology , 2007,
Abstract: Muon storage rings have been proposed for use as a source of high-energy neutrino beams (the Neutrino Factory) and as the basis for a high-energy lepton-antilepton collider (the Muon Collider). The Neutrino Factory is widely believed to be the machine of choice for the search for leptonic CP violation while the Muon Collider may prove to be the most practical route to multi-TeV lepton-antilepton collisions. The baseline conceptual designs for each of these facilities requires the phase-space compression (cooling) of the muon beams prior to acceleration. The short muon lifetime makes it impossible to employ traditional techniques to cool the beam while maintaining the muon-beam intensity. Ionization cooling, a process in which the muon beam is passed through a series of liquid-hydrogen absorbers followed by accelerating RF cavities, is the technique proposed to cool the muon beam. The international Muon Ionization Cooling Experiment (MICE) collaboration will carry out a systematic study of ionization cooling. The MICE experiment, which is under construction at the Rutherford Appleton Laboratory, will begin to take data late this year. The MICE cooling channel, the instrumentation and the implementation at the Rutherford Appleton Laboratory are described together with the predicted performance of the channel and the measurements that will be made.
MICE: The International Muon Ionization Cooling Experiment  [PDF]
D. M. Kaplan,K. Long
Physics , 2007,
Abstract: Muon storage rings have been proposed for use as a source of high-energy neutrino beams (the Neutrino Factory) and as the basis for a high-energy lepton-antilepton collider (the Muon Collider). The Neutrino Factory is widely believed to be the machine of choice for the search for leptonic CP violation while the Muon Collider may prove to be the most practical route to multi-TeV lepton-antilepton collisions. The baseline conceptual designs for each of these facilities requires the phase-space compression (cooling) of the muon beams prior to acceleration. The short muon lifetime makes it impossible to employ traditional techniques to cool the beam while maintaining the muon-beam intensity. Ionization cooling, a process in which the muon beam is passed through a series of liquid-hydrogen absorbers followed by accelerating RF cavities, is the technique proposed to cool the muon beam. The international Muon Ionization Cooling Experiment (MICE) collaboration will carry out a systematic study of ionization cooling. The MICE experiment, which is under construction at the Rutherford Appleton Laboratory, will begin to take data late this year. The MICE cooling channel, the instrumentation and the implementation at the Rutherford Appleton Laboratory are described together with the predicted performance of the channel and the measurements that will be made.
Bethe-Heitler cross-section for very high photon energies and large muon scattering angles  [PDF]
Gerhard Baur,Albrecht Leuschner
Physics , 1999, DOI: 10.1007/s100529900028
Abstract: The cross-section for the process $\gamma + A \to \mu^+ + \mu^- + X$ is studied where the photon energy is of the order of several hundreds of GeV and where one of the leptons is scattered to large angles. This is of practical importance for muon shielding calculations at future linear electron colliders. In addition to the photon pole contribution which was previously considered especially by Y.S.Tsai, we identify another component due to the muon pole (equivalent photon and equivalent muon approximation). This is discussed following the usual Bethe-Heitler formula. Then we give practically useful formulae for inclusive lepton (muon) production along with some numerical examples.
Some problems in plasma suppression of beam-beam interactions at muon colliders  [PDF]
Valery Telnov
Physics , 2000, DOI: 10.1063/1.1361691
Abstract: The idea of plasma suppression of beam-beam effects at muon colliders is discussed. It is shown that one should take into account collisions in the plasma that were ignored before. Rough estimates show that this effect leads to a fast ``recovery'' of the beam magnetic field. For beam parameters characteristic for muon colliders the suppression of the magnetic component of the beam field (1/2 of the total force) is almost absent. It is also shown that the presence of the dense plasma (Li jet) at the interaction point leads to enormous hadronic background (due to photo-nuclear reactions) in the detector, about 10^{7} particles per crossing at large angles which creates serious problems for experimentation.
Paying for the Orphan Drug System: break or bend? Is it time for a new evaluation system for payers in Europe to take account of new rare disease treatments?
Hughes-Wilson Wills,Palma Ana,Schuurman Ad,Simoens Steven
Orphanet Journal of Rare Diseases , 2012, DOI: 10.1186/1750-1172-7-74
Abstract: Since its enactment in 2000, the European Orphan Medicinal Products Regulation has allowed the review and approval of approaching 70 treatments for some 55 different conditions in Europe. Success does not come without a price, however. Many of these so-called “orphan drugs” have higher price points than treatments for more common diseases. This has been raising debate as to whether the treatments are worth it, which, in turn risks blocking patient access to treatment. To date, orphan drugs have only accounted for a small percentage of the overall drug budget. It would appear that, with increasing numbers of orphan drugs, governments are concerned about the future budget impact and their cost-effectiveness in comparison with other healthcare interventions. Orphan drugs are under the spotlight, something that is likely to continue as the economic crisis in Europe takes hold and governments respond with austerity measures that include cuts to healthcare expenditures. Formally and informally, governments are looking at how they are going to handle orphan drugs in the future. Collaborative proposals between EU governments to better understand the value of orphan drugs are under consideration. In recent years there has been increasing criticism of behaviours in the orphan drug field, mainly centring on two key perceptions of the system: the high prices of orphan drugs and their inability to meet standard cost-effectiveness thresholds; and the construct of the system itself, which allows companies to gain the benefits that accrue from being badged as an orphan drug. The authors hypothesise that, by examining these criticisms individually, one might be able to turn these different “behaviours” into criteria for the creation of a system to evaluate new orphan drugs coming onto the market. It has been acknowledged that standard methodologies for Health Technology Assessments (HTA) will need to be tailored to take into account the specificities of orphan drugs given that the higher price-points claimed by orphan drugs are unlikely to meet current cost-effectiveness thresholds. The authors propose the development of a new assessment system based on several evaluation criteria, which would serve as a tool for Member State governments to evaluate each new orphan drug at the time of pricing and reimbursement. These should include rarity, disease severity, the availability of other alternatives (level of unmet medical need), the level of impact on the condition that the new treatment offers, whether the product can be used in one or more indications, the level of resear
Medical Student Dissection of CadaversImproves Performance on Practical Exams, but not Dissection-Relevant Questions in the NBME Gross Anatomy and Embryology Final Exam  [cached]
Leslie Sargent Jones
Medical Education Online , 2001,
Abstract: We have examined whether cadaver dissection by first year medical students (MIs) affected their performance in two test measures: the NBME Gross Anatomy and Embryology Subject Exam (dissection-relevant questions only), and practical exams given at the end of each major section within the course. The dissections for the entire course were divided into 18 regional dissection units and each student was assigned to dissect one third of the regional units; the other two-thirds of the material was learned from the partner-prosected cadavers. Performance for each student on the exams was then assessed as a function of the regions those students actually dissected. While the results indicated a small performance advantage for MIs answering questions on material they had dissected on the NBME Subject Exam questions relevant to dissection (78-88% of total exam), the results were not statistically significant. However, a similar, small performance advantage on the course practical exams was highly significant.
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