54 research outputs found
Dental treatment and risk of variant CJD - a case control study
Abstract
Objective: Knowledge of risk factors for variant CJD (vCJD) remains limited, but transmission of prion proteins via re-useable medical devices, including dental instruments, or enhanced susceptibility following trauma to the oral cavity is a concern. This study aimed to identify whether previous dental treatment is a risk factor for development of vCJD.
Design: Case control study
Methods: Risk factor questionnaires completed by interview with relatives of 130 vCJD patients and with relatives of 66 community and 53 hospital controls were examined by a dental surgeon. Responses regarding dental treatments were analysed.
Results: We did not find a statistically significant excess of risk of vCJD associated with dental treatments with the exception of extractions in an unmatched analysis of vCJD cases with community controls (p=0.02). However, this result may be explained by multiple testing.
Conclusions: This is the first published study to date to examine potential links between vCJD and dental treatment. There was no convincing evidence found of an increased risk of variant CJD associated with reported dental treatment. However, the power of the study is restricted by the number of vCJD cases to date and does not preclude the possibility that some cases have resulted from secondary transmission via dental procedures. Due to the limitations of the data available, more detailed analyses of dental records are required to fully exclude the possibility of transmission via dental treatment
Technology Contribution to Improve Autistic Children Life Quality
To review published literature on the use of technology and how it has improved autistic children life style. A systematic review of the English literature was performed using the PRISMA guideline. Papers indexed in WOS and Scopus databases were included, adjusted to a timeline between 2016 and 2020 and focused on mobile technology, interventions, improvement of social behavior and communication and autism, aimed to describe the most used mechanism to improve autistic life style. Thirty two (32) papers were included in the review. We obtained 14 papers on the Scopus database and 18 on the WOS database. The majority of studies evidenced the use of virtual reality, mobile devices, video modelling and robots as the most common applications for autism therapies. Technology has caused an improvement in autistic children life quality. The development of mobile applications, virtual reality applications and robots have showed a positive impact reflected in the performance of daily activities and a better understanding of how they feel, how to behave, how to express themselves and interact with others. Technology gives the opportunity to monitor children status; and offers adaptability, safety, and accuracy of the information
2023 Astrophotonics Roadmap: pathways to realizing multi-functional integrated astrophotonic instruments
This is the final version. Available on open access from IOP Publishing via the DOI in this recordData availability statement:
The data that support the findings of this study are available upon reasonable request from the authors.Photonic technologies offer numerous functionalities that can be used to realize astrophotonic instruments. The most spectacular example to date is the ESO Gravity instrument at the Very Large Telescope in Chile that combines the light-gathering power of four 8 m telescopes through a complex photonic interferometer. Fully integrated astrophotonic devices stand to offer critical advantages for instrument development, including extreme miniaturization when operating at the diffraction-limit, as well as integration, superior thermal and mechanical stabilization owing to the small footprint, and high replicability offering significant cost savings. Numerous astrophotonic technologies have been developed to address shortcomings of conventional instruments to date, including for example the development of photonic lanterns to convert from multimode inputs to single mode outputs, complex aperiodic fiber Bragg gratings to filter OH emission from the atmosphere, complex beam combiners to enable long baseline interferometry with for example, ESO Gravity, and laser frequency combs for high precision spectral calibration of spectrometers. Despite these successes, the facility implementation of photonic solutions in astronomical instrumentation is currently limited because of (1) low throughputs from coupling to fibers, coupling fibers to chips, propagation and bend losses, device losses, etc, (2) difficulties with scaling to large channel count devices needed for large bandwidths and high resolutions, and (3) efficient integration of photonics with detectors, to name a few. In this roadmap, we identify 24 key areas that need further development. We outline the challenges and advances needed across those areas covering design tools, simulation capabilities, fabrication processes, the need for entirely new components, integration and hybridization and the characterization of devices. To realize these advances the astrophotonics community will have to work cooperatively with industrial partners who have more advanced manufacturing capabilities. With the advances described herein, multi-functional integrated instruments will be realized leading to novel observing capabilities for both ground and space based platforms, enabling new scientific studies and discoveries.National Science Foundation (NSF)NAS
Mesure des aberrations thermiques dans un laser YVO en fonctionnement, pompé longitudinalement par diode
Nous avons étudié les distorsions thermiques dans un laser Nd :YVO continu. pompé par diode, en utilisant un faisceau sonde externe spatialement monomode. AprÚs une double traversée de ce faisceau sonde dans le milieu amplificateur, trois profils d'éclairement sont enregistrés le long de son axe de propagation. Le profil de phase distordu est alors reconstruit par un algorithme itératif de type Gerchberg-Saxton. La contribution de chaque type d'aberration est ensuite déterminée grùce à ofil de hase reconstruit sur la base des polynÎmes de Zernike
Effect of spectral sampling on the temporal coherence analysis of a broadband source in a SFG interferometer
International audienceIn the frame of sum frequency generation of a broadband infrared source, we aim to enlarge the converted bandwidth by using a pump frequency comb while keeping a high conversion efficiency. The nonlinear effects are simultaneously induced in the same nonlinear medium. In this paper, we investigate the spectral filtering effect on the temporal coherence behavior with a Mach-Zehnder interferometer using two pump lines. We show that joined effects of quasi-phase matching and spectral sampling lead to an original coherence behavior
Laser à trois miroirs applicable à la génération de microondes
Un laser à trois miroirs émettant un signal microonde par battement de deux fréquences optiques est étudié numériquement et expérimentalement. L'écart fréquentiel entre les deux modes émis est finement ajustable par modifications des longueurs des sous-cavités
Supercontinuum generation in air-silica microstructured fibers with nanosecond and femtosecond pulse pumping
International audienc
Observation of soliton emission and soliton reflection in engineered bulk PPLN structures at 1064 nm
International audienc
Comment lâutilisation de PPLN peut rĂ©volutionner lâastronomie moyen infrarouge
International audienceALOHA est un projet visant Ă utiliser les technologies de lâoptique non linĂ©aire et guidĂ©e dans le domaine de lâimagerie haute rĂ©solution en astronomie infrarouge. Notre dĂ©marche consiste Ă inclure un processus de conversion de frĂ©quence sur chaque bras de lâinterfĂ©romĂštre<br>pour transposer le signal infrarouge moyen vers le proche infrarouge. Cette mĂ©thode permet de relĂącher les contraintes sur le bruit thermique de lâinstrument et de disposer des composants matures de lâoptique guidĂ©e. Les premiers tests en laboratoire ont permis de rĂ©aliser des franges dâinterfĂ©rence avec un contraste supĂ©rieur Ă 95% avec 100 fW Ă lâentrĂ©e de chaque bras. Lâutilisation de PPLN ridge pourrait significativement amĂ©liorer ces rĂ©sultats
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