137 research outputs found
There is no "Theory of Everything" inside E8
We analyze certain subgroups of real and complex forms of the Lie group E8,
and deduce that any "Theory of Everything" obtained by embedding the gauge
groups of gravity and the Standard Model into a real or complex form of E8
lacks certain representation-theoretic properties required by physical reality.
The arguments themselves amount to representation theory of Lie algebras in the
spirit of Dynkin's classic papers and are written for mathematicians.Comment: Final version, to appear in Communications in Mathematical Physics.
The main difference, from the previous version, is the creation of a new
section, containing a response to Lisi's objections to our wor
Smartphone-Based Virtual Agents Can Help the General Population Concerned by Sleep Complaints: A Proof-of-Concept Study During COVID-19 Confinement
Background: The COVID-19 crisis induces psychosocial stress and sleep complaints that require early management. KANOPEE is a smartphone-based application, providing an interaction with a virtual agent dedicated to screen and deliver behavioral interventions to fight sleep disorders. This paper describes the feasibility study of this application, during the context of COVID-19 confinement in France. Method: 2,069 users of aged 18 years and over downloaded the app during the inclusion period (between 22 April and 5 May 2020). Users first answered a screening interview based on the insomnia severity index (ISI) that was conducted by the virtual agent. If participants were positive for insomniac complaints (ISI > 14), they could join a two-stage intervention program: a) complete an electronic sleep diary for one week, and b) follow personalized sleep recommendations for 10 days. Measures collected included socio-demographic information, ISI and sleep/wake schedules; and acceptance and trust of the agent.Bordeaux Region Aquitaine Initiative for NeurosciencePhénotypage humain et réalité virtuell
J Med Internet Res
Background: The COVID-19 crisis and consequent confinement restrictions have caused significant psychosocial stress and reports of sleep complaints, which require early management, have increased during recent months. To help individuals concerned about their sleep, we developed a smartphone-based app called KANOPEE that allows users to interact with a virtual agent dedicated to autonomous screening and delivering digital behavioral interventions. Objective: Our objective was to assess the feasibility of this app, in terms of inclusion rate, follow-up rate, perceived trust and acceptance of the virtual agent, and effects of the intervention program, in the context of COVID-19 confinement in France. Methods: The virtual agent is an artificial intelligence program using decision tree architecture and interacting through natural body motion and natural voice. A total of 2069 users aged 18 years and above downloaded the free app during the study period (April 22 to May 5, 2020). These users first completed a screening interview based on the Insomnia Severity Index (ISI) conducted by the virtual agent. If the users were positive for insomnia complaints (ISI score >14), they were eligible to join the 2-stage intervention program: (1) complete an electronic sleep diary for 1 week and (2) follow personalized sleep recommendations for 10 days. We collected and analyzed the following measures: sociodemographic information, ISI scores and sleep/wake schedules, and acceptance and trust of the agent. Results: Approximately 76% (1574/2069) of the app users completed the screening interview with the virtual agent. The virtual agent was well accepted by 27.4% (431/1574) of the users who answered the acceptance and trust questionnaires on its usability, satisfaction, benevolence, and credibility. Of the 773 screened users who reported sleep complaints (ISI score >14), 166 (21.5%) followed Step 1 of the intervention, and only 47 of those (28.3%) followed Step 2. Users who completed Step 1 found that their insomnia complaints (baseline mean ISI score 18.56, mean ISI score after Step 1 15.99; P21) did not respond to either intervention. Conclusions: These preliminary results suggest that the KANOPEE app is a promising solution to screen populations for sleep complaints and that it provides acceptable and practical behavioral advice for individuals reporting moderately severe insomnia.Bordeaux Region Aquitaine Initiative for NeurosciencePhénotypage humain et réalité virtuell
An Antiproton Decelerator in the CERN PS Complex
The present CERN PS low-energy antiproton complex involves 4 machines to collect, cool, decelerate and supply experiments with up to 1010 antiprotons per pulse and per hour of momenta ranging from 0.1 to 2 GeV/c. In view of a possible future physics programme requiring low energy antiprotons, mainly to carry out studies on antihydrogen, a simplified scheme providing at low cost antiprotons at 100 MeV/c has been studied. It requires only one machine, the present Antiproton Collector (AC) converted into a cooler and decelerator (Antiproton Decelerator, AD) and delivering beam to experiments in the hall of the present Antiproton Accumulator Complex (AAC) [1]. This paper describes the feasibility study of such a scheme [2]
The antiproton decelerator: AD
A simplified scheme for the provision of antiprotons at 100 MeV/c based on fast extraction is described. The scheme uses the existing production target area and the modified Antiproton Collector Ring in their current location. The physics programme is largely based on capturing and storing antiprotons in Penning traps for the production and spectroscopy of antihydrogen. The machine modifications necessary to deliver batches of 1 107 /min at 100 MeV/c are described. Details of the machine layout and the experimental area in the existing AAC Hall are given
COMPLIS experiments : COllaboration for spectroscopy Measurements using a Pulsed Laser Ion Source
Laser spectroscopy measurements have been carried out on very neutron-deficient isotopes of Au, Pt and Ir, produced as daughter elements from a Hg ISOLDE beam. For these transitional region nuclides, the hyperfine structure (HFS) and isotope shift (IS) were measured by Resonance Ionization Spectroscopy (RIS). Magnetic moments μ, spectroscopic quadrupole moments Qs and changes of the nuclear mean square charge radius δ〈rc 2〉along isotopic series have been extracted. For some results, a detailed comparison with theoretical predictions is presented. (Springer
The antiproton decelerator (AD), a simplified antiproton source (feasibility study)
In view of a possible future physics programme concerning antihydrogen a simplified scheme for the provision of antiprotons of a few MeV has been studied. It uses the present target area and the modified Antiproton Collector (AC) in its present location. In this report all the systems are reviewed and their modifications discussed
Grafted Human Embryonic Progenitors Expressing Neurogenin-2 Stimulate Axonal Sprouting and Improve Motor Recovery after Severe Spinal Cord Injury
7 p.Background: Spinal cord injury (SCI) is a widely spread pathology with currently no effective treatment for any symptom. Regenerative medicine through cell transplantation is a very attractive strategy and may be used in different non-exclusive ways to promote functional recovery. We investigated functional and structural outcomes after grafting human embryonic neural progenitors (hENPs) in spinal cord-lesioned rats.Methods and Principal Findings: With the objective of translation to clinics we have chosen a paradigm of delayed grafting, i.e., one week after lesion, in a severe model of spinal cord compression in adult rats. hENPs were either naive or engineered to express Neurogenin 2 (Ngn2). Moreover, we have compared integrating and non-integrating lentiviral vectors, since the latter present reduced risks of insertional mutagenesis. We show that transplantation of hENPs transduced to express Ngn2 fully restore weight support and improve functional motor recovery after severe spinal cord compression at thoracic level. This was correlated with partial restoration of serotonin innervations at lumbar level, and translocation of 5HT1A receptors to the plasma membrane of motoneurons. Since hENPs were not detectable 4 weeks after grafting, transitory expression of Ngn2 appears sufficient to achieve motor recovery and to permit axonal regeneration. Importantly, we also demonstrate that transplantation of naive hENPs is detrimental to functional recovery.Conclusions and Significance: Transplantation and short-term survival of Ngn2-expressing hENPs restore weight support after SCI and partially restore serotonin fibers density and 5HT1A receptor pattern caudal to the lesion. Moreover, grafting of naive-hENPs was found to worsen the outcome versus injured only animals, thus pointing to the possible detrimental effect of stem cell-based therapy per se in SCI. This is of major importance given the increasing number of clinical trials involving cell grafting developed for SCI patients.This study was supported by the European Union FP6 "RESCUE" STREP; the "Institut pour la Recherche sur la Moelle Epiniere"; the "Academie de Medecine"; the "Societe Francaise de Neurochirurgie"; "Verticale" and the "Association Demain Debout Aquitaine". The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Biodiversity of soils and farming innovations for improved resilience of European wheat agrosystems (BIOFAIR)
BIOFAIR holistically determines soil biodiversity under different farming practices and environmental stressors to anticipate negative impacts of climate change on belowground processes and provide adaptation strategies. The BIOFAIR project comprehensively addresses the diversity of soil organisms, from microbes to mites, and how they link to soil functioning in terms of disease suppression and carbon and nutrient cycling. On the crop site, a specific focus is given to grain quality parameters such as vitamin and mineral nutrient contents essential for many human body functions, and to technological bread making properties such as flour viscosity, to ensure the crops of the future have a high nutritious value and are suitable for food production.2. Zero hunger3. Good health and well-being12. Responsible consumption and production13. Climate action15. Life on land17. Partnerships for the goal
Biodiversity of soils and farming innovations for improved resilience of European wheat agrosystems (BIOFAIR)
IOFAIR holistically determines soil biodiversity under different farming practices and environmental stressors to anticipate negative impacts of climate change on belowground processes and provide adaptation strategies. The BIOFAIR project comprehensively addresses the diversity of soil organisms, from microbes to mites, and how they link to soil functioning in terms of disease suppression and carbon and nutrient cycling. On the crop site, a specific focus is given to grain quality parameters such as vitamin and mineral nutrient contents essential for many human body functions, and to technological bread making properties such as flour viscosity, to ensure the crops of the future have a high nutritious value and are suitable for food production
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