1,678 research outputs found
The supersymmetric Higgs sector and B-Bbar mixing for large tan beta
We match the Higgs sector of the most general flavour breaking and CP
violating minimal supersymmetric standard model (MSSM) onto a generic
two-Higgs-doublet model, paying special attention to the definition of tan beta
in the effective theory. In particular no tan beta-enhanced loop corrections
appear in the relation to tan beta defined in the DRbar scheme in the MSSM. The
corrections to the Higgs-mediated flavour-changing amplitudes which result from
this matching are especially relevant for the B_d and B_s mass differences
dM_s,d for minimal flavour violation, where the superficially leading
contribution vanishes. We give a symmetry argument to explain this cancellation
and perform a systematic study of all Higgs-mediated effects, including Higgs
loops. The corrections to dM_s are at most 7% for mu>0 and M_A < 600 if
constraints from other observables are taken into account. For mu<0 they can be
larger, but are always less than about 20%. Contrary to recent claims we do not
find numerically large contributions here, nor do we find any tan beta-enhanced
contributions from loop corrections to the Higgs potential in B^+ -> tau^+ nu
or B -> X_s gamma. We further update supersymmetric loop corrections to the
Yukawa couplings, where we include all possible CP-violating phases and correct
errors in the literature. The possible presence of CP-violating phases
generated by Higgs exchange diagrams is briefly discussed as well. Finally we
provide improved values for the bag factors P^VLL_1, P^LR_2, and P^SLL_1 at the
electroweak scale.Comment: 61 page
JumpSat Thermal and Mechanical Analysis
In 2017, Swiss Space Systems (S3) is planned to operate unmanned suborbital space planes for launching small satellites. Within this scenario it was supposed to be launched JumpSat, a 3-Units CubeSat developed by ISAE-SUPAERO students, in collaboration with ONERA, CNES, and TELECOM Bretagne. JumpSat mission was proposed by ISAE in 2012. Their main objectives are both in-orbit technological demonstration and scientific research [1], through an elliptical Low Earth Orbit (LEO). The students are entirely involved in this mission, beyond both technological and scientific objectives, from the early stage to the disposal. ONERA, in Toulouse, is developing Dynagrad, a radiation sensor for trapped particles in the Earthâs magnetic belts, especially in the South Atlantic Anomaly (SAA), to improve the current models of radiation and their accuracy. Space qualification for a low-cost Star Tracker is under development at ISAE-SUPAERO. It will provide enough useful knowledge about system concept and software development for future small satellites missions. Another technological demonstration will accomplish a space qualification for the three-axis attitude control sub-system (AOCS) within the JumpSat mission. The acquired knowledge will help future CubeSatsAOCS sub-systems, while other components are COTS.Moreover, a consortium with Thales Alenia Space, LAAS and ISAE-SUPAERO designed NIPMH (Nanosatellite Investigate Microwave Photonic Hardware), an experimental payload based on opto-microwave technology. It would be embedded in a 3U CubeSat for testing different components sensitivity to radiations in space, especially the optical fiber doped with erbium. Furthermore,due to the similarities among both missions, it was analyzed the possibility of the combination of both projects: NIMPH as an additional payload to JumpSat mission. It increases the mission duration up to a minimum of two years, with respect to French law for Space Operations (maximal mission duration: 25 years). This paper will focus on mechanical and thermal aspects that were completely redesigned for JumpSat to comply with all requirements of both missions. From that point comes out the idea of building the first 6U CubeSat by ISAE-SUPAERO. As those studies are present in all design phases, they have important impact on the optimal architecture design within all the subsystems. Finally, temperatures gradients are such a great problem in space that it is even more important with strong radiation doses, like for this mission. Then, thermal analysis for worst cold and hot cases is critical for analyzing the impact of the new payload within the mission
Plant economy during the Neolithic in a mountain context: the case of "Le Chenet des Pierresâ in the French Alps (Bozel-Savoie, France)
The analyses of archaeobotanical assemblages recovered in recent excavations in the northern French Alps permit a better understanding of the way people managed plant resources in a mountain context during the Middle Neolithic (4500-3500cal b.c.). The aim of this paper is to shed new light on the question of crop cultivation as well as wood gathering and management from the results of the new archaeobotanical investigations at "Le Chenet des Pierresâ in Bozel (Savoie, France; 1,000m. a.s.l.). The study reveals the presence of cereals like einkorn (Triticum monococcum), emmer (T. dicoccum), naked wheat (T. aestivum/durum/turgidum) and barley (Hordeum vulgare/distichon). In addition wild fruits and nuts, probably gathered, such as hazelnuts (Corylus avellana), wild apples (Malus sylvestris), arolla pine kernels (Pinus cembra), sloes (Prunus spinosa) and raspberries (Rubus idaeus) were recorded. The anthracological analysis shows that the occupants exploited mostly a mixed oak forest, and the available woodland from the alluvial forest to the mountain areas. With the archaeobotanical study of "Le Chenet des Pierresâ we also want to raise the question of crop cultivation in a mountain context. Although present data show that cultivation at higher altitudes is common, it is still difficult to demonstrate the inhabitants cultivated plants near their settlement during the Neolithi
Research Brief No. 10 - Analyzing Canadian Women Working after Childbirth as Lifecourse Transition
This research focused on Canadian mothers who had a first child between 1970 and 1999, and the probability of these mothers working shortly after childbearing. Authors StĂ©phanie Gaudet, Martin Cooke and Joanna Jacob studied the change and underlying dynamics with two main questions. First, what are the characteristics that affect Canadian womenâs employment? And how have womenâs employment transitions after the birth of a first child changed over time? The investigators probed the effects of socioeconomic characteristics on labor force withdrawal using the 2001 General Social Survey, Cycle 15 on Family History. Employment transition was viewed through a type of lifecourse analysis for six cohorts of mothers over the 30-year span. Gaudet, Cooke and Jacob attempted to understand underlying inter-cohort differences through individual characteristics such as level of education, age at childbearing, employment before childbearing, and spousal income. The researchers concluded that since the mid-1980s, mothers with low educational attainment are largely excluded from the labor market during the two years following the birth of their first child
Mise sous assurance qualité d'un laboratoire en Nouvelle-Calédonie, selon la norme NF EN ISO/CEI 17025, dans un but d'accréditation
L'accréditation Cofrac offre une garantie de sérieux et de compétence technique dont les laboratoires peuvent difficilement se passer aujourd'hui face aux exigences de leurs clients qui ont besoin d'une reconnaissance mondiale des analyses effectuées sur leurs produits. Les prescriptions générales auxquelles les laboratoires doivent répondre pour pouvoir prétendre à une accréditation sont définies dans une norme, la NF EN ISO/CEI 17025, qui est en application depuis mai 2000 et ne remplacera la précédente que fin 2002. Dans ce travail l'auteur présente l'évolution des prescriptions générales entre la NF EN 45001 et la NF EN ISO/CEI 17025. Il évoque également les autres exigences auxquelles doivent répondre les laboratoires dans l'objectif d'une demande d'accréditation. Puis il présente les moyens mis en oeuvre par un laboratoire de Nouvelle-Calédonie dans le but d'obtenir l'accréditation pour deux programmes cofrac. Enfin le processus général d'accréditation par le Cofrac, depuis l'instruction du dossier d'inscription jusqu'au déroulement des audits, est abordé
Understanding and Decoding Imagined Speech using Electrocorticographic Recordings in Humans
Certain brain disorders, resulting from brainstem infarcts, traumatic brain injury, stroke and amyotrophic lateral sclerosis, limit verbal communication despite the patient being fully aware. People that cannot communicate due to neurological disorders would benefit from a system that can infer internal speech directly from brain signals. Investigating how the human cortex encodes imagined speech remains a difficult challenge, due to the lack of behavioral and observable measures. As a consequence, the fine temporal properties of speech cannot be synchronized precisely with brain signals during internal subjective experiences, like imagined speech. This thesis aims at understanding and decoding the neural correlates of imagined speech (also called internal speech or covert speech), for targeting speech neuroprostheses. In this exploratory work, various imagined speech features, such as acoustic sound features, phonetic representations, and individual words were investigated and decoded from electrocorticographic signals recorded in epileptic patients in three different studies. This recording technique provides high spatiotemporal resolution, via electrodes placed beneath the skull, but without penetrating the cortex In the first study, we reconstructed continuous spectrotemporal acoustic features from brain signals recorded during imagined speech using cross-condition linear regression. Using this technique, we showed that significant acoustic features of imagined speech could be reconstructed in seven patients. In the second study, we decoded continuous phoneme sequences from brain signals recorded during imagined speech using hidden Markov models. This technique allowed incorporating a language model that defined phoneme transitions probabilities. In this preliminary study, decoding accuracy was significant across eight phonemes in one patients. In the third study, we classified individual words from brain signals recorded during an imagined speech word repetition task, using support-vector machines. To account for temporal irregularities during speech production, we introduced a non-linear time alignment into the classification framework. Classification accuracy was significant across five patients. In order to compare speech representations across conditions and integrate imagined speech into the general speech network, we investigated imagined speech in parallel with overt speech production and/or speech perception. Results shared across the three studies showed partial overlapping between imagined speech and speech perception/production in speech areas, such as superior temporal lobe, anterior frontal gyrus and sensorimotor cortex. In an attempt to understanding higher-level cognitive processing of auditory processes, we also investigated the neural encoding of acoustic features during music imagery using linear regression. Despite this study was not directly related to speech representations, it provided a unique opportunity to quantitatively study features of inner subjective experiences, similar to speech imagery. These studies demonstrated the potential of using predictive models for basic decoding of speech features. Despite low performance, results show the feasibility for direct decoding of natural speech. In this respect, we highlighted numerous challenges that were encountered, and suggested new avenues to improve performances
PhysiothĂ©rapie et douleur lombo-pelvienne chez la femme enceinte : Un appel Ă lâaction
Travail d'intĂ©gration prĂ©sentĂ© Ă Isabelle Gagnon dans le cadre du cours PHT-6113.ProblĂ©matique : La douleur lombo-pelvienne est une plainte frĂ©quemment rencontrĂ©e chez la femme enceinte. Selon les Ă©tudes, lâincidence varie de 24% Ă 90%. Le mythe que la douleur lombo-pelvienne fait partie du processus normal de la grossesse et la croyance rĂ©pandue quâil nây a rien Ă faire pour limiter les symptĂŽmes font en sorte que cette clientĂšle est sous-traitĂ©e par les physiothĂ©rapeutes.
Objectifs : Les objectifs du projet Ă©taient 1) dâexplorer la pratique clinique actuelle en physiothĂ©rapie ainsi que lâattitude des physiothĂ©rapeutes face Ă la prise en charge de femmes enceintes souffrant de douleurs lombo-pelviennes, 2) dâidentifier la prise en charge optimale Ă prĂ©coniser et 3) dâĂ©laborer des stratĂ©gies de transfert des connaissances acquises.
MĂ©thodes : Un sondage a Ă©tĂ© effectuĂ© auprĂšs de physiothĂ©rapeutes afin de dĂ©terminer la pratique clinique actuelle et leur sentiment de compĂ©tence face Ă cette clientĂšle. De plus, une recension des Ă©crits concernant lâĂ©pidĂ©miologie, les changements physiologiques, lâĂ©valuation et le traitement en physiothĂ©rapie a Ă©tĂ© rĂ©alisĂ©e. Finalement, un site web visant les professionnels de la physiothĂ©rapie fut prĂ©parĂ©.
RĂ©sultats : Des incertitudes quant aux prĂ©cautions et contre-indications Ă prendre face Ă lâĂ©valuation (19,7%), au traitement (40,3%) et Ă la prescription dâentrainement musculaire (25,2%) et cardio-vasculaire (35,1%) persistent chez un nombre important de physiothĂ©rapeutes. Lors de lâĂ©valuation, il est particuliĂšrement important de diffĂ©rencier les douleurs dâorigine lombaire et pelvienne. Il semble y avoir des Ă©vidences sur lâefficacitĂ© des exercices en piscine ainsi que sur lâacuponcture pour traiter cette clientĂšle.
Conclusion : Lâinsuffisance dâĂ©vidences scientifiques ainsi que le manque de confiance des physiothĂ©rapeutes en ce qui concerne la pratique limitent la prise en charge optimale de cette clientĂšle
On the Development of a Computer-Based Tool for Formative Student Assessment: Epistemological, Methodological, and Practical Issues
Formative assessments in schools have the potential to improve studentsâ learning outcomes and self-regulation skills; they make learning visible and provide evidence-based guidelines for setting up and pursuing individual learning goals. With the recent introduction of the computer-based formative assessment systems for the educational contexts, there is much hope that such systems will provide teachers and students with valuable information to guide the learning process without taking much time from teaching and learning to spend on generating, evaluating and interpreting assessments. In this paper, we combine the theoretical and applied perspectives by addressing (a) the epistemological aspects of the formative assessment, with an emphasis on data collection, model building, and interpretation; (b) the methodological challenges of providing feedback in the context of instruction in the classroom; and (c) practical requirements for and related challenges of setting up and delivering the assessment system to a large number of students. In the epistemological section, we develop and explicate the interpretive argument of formative assessment and discuss the challenges of obtaining data with high validity. From the methodological perspective, we argue that computer-based formative assessment systems are generally superior to the traditional methods of providing feedback in the classroom, as they better allow supporting inferences of the interpretive argument. In the section on practical requirements, we first introduce an existing computer-based formative assessment system, as a case in point, for discussing related practical challenges. Topics covered in this section comprise the specifications of assessment content, the calibration and maintenance of the item bank, challenges concerning teachersâ and studentsâ assessment literacy, as well as ethical and data-protection requirements. We conclude with an outlook on possible future directions for computer-based formative assessment systems and the field in general
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