392 research outputs found
Soutenance M. Plard 06/12/12
No full textVieillissement et care dans les familles transnationales indiennes. Expériences de vie de brahmanes à Chennai et Coimbatore Composition du jury Raymonde Séchet, Professeure des universités, Rennes 2 Patrick Gonin, Professeur des universités, Poitiers Christophe Z. Guilmoto, Directeur de recherche, IRD Christian Pihet, Professeur des universités, Angers Sébastien Fleuret, Chargé de recherche, CNRS La thèse sera présentée et soutenue à l'université d'Angers, le jeudi 6 décembre à 14h à la MSH (..
Calibration of a Photometric Filter System with a 5-inch Telescope Subsystem of the MAGIC Telescopes
No full textIn this Bachelor thesis, the photometric calibration of the 5-inch MAGIC Atmosphere Minion (MAM) telescope on the Canary Island of La Palma, Spain, is presented. The telescope is supposed to measure the atmospheric transmission in real time and in pointing direction of the Major Atmospheric Gamma-Ray Imaging Cherenkov (MAGIC) telescopes, also situated on La Palma. Different concepts of photometry are discussed and their suitability is evaluated according to the special observing conditions in which MAM will be operating. These include possibly challenging weather conditions, very large zenith angle observations, and an automatic mode of operation. The task of MAM is motivated by the need to correct MAGIC data for the effect of atmospheric extinction. When a gamma ray enters Earth’s atmosphere it produces an electromagnetic air shower of secondary particles, which can be observed by MAGIC because of the Cherenkov radiation they emit. Knowledge about the amount of Cherenkov light surviving the way through the atmosphere is crucial for the correct reconstruction of the primary gamma-ray energy. MAM is equipped with two telescope tubes, a spectrograph, and several cameras for imaging. Only the 5-inch telescope and a CMOS camera were used for this Bachelor work. The calibration measurement was done remotely during good weather conditions. Five stars with a wide range of color indices were observed in the l, r, g, and b filter from the Baader company and at different zenith angles ranging from 28° to 80°. Existing software and some modules, especially written for the purpose of this thesis, were used for the control of the telescope. From the data, extinction coefficients in different bands of the visible spectrum at the site of the Roque de los Muchachos observatory were calculated and compared to other measurements. They were found to match the expectation and agree with the dependency on wavelength and color of the observed star. As a final result, color transformation relations between the Landolt photometric standard system and the MAM observational system were derived for the filters r, g and b. The results for filter r are found to be inconsistent and an attempt is made to explain this. Results for filter g and b are consistent and stable, but precision should be improved to enable more concrete statements. The main conclusion is that more stars are needed to reliably characterise the transformation relations and reduce uncertainties. A reevaluation of the photometric concepts shows that the concept based on an existing catalog of stars has potential for success, but is more complex and susceptible for systematic uncertainties arising from the transformation between photometric systems. The concept based on the MAM observational system is simpler and can give quicker first results with less effort
Folklore de France
No full textTitre uniforme : [L'Ajaccienne]Comprend : Fête de la bière à Schiltigheim : polka pour pistons / F. Linck ; Musique folklorique alsacienne Schnokelock dir. J. Mayer - Bergeronnette savoisienne : choeur XVème siècle / Choeur du Cercle Philharmonique de Chambéry dir. M. Lombard - Joyeuse Franche-Comté / A. Gossez ; Albert Gossez et ses Joyeux Franc-Comtois - Lo Gobatchouno : bourrée / M. Bernard et J. Vaissade ; Marcel Bernard, sa cabrette et son ensemble régional d'Auvergne - Le P'tit quinquin / Desrousseaux et Drugbert ; Marcel Wiedaghe et son Ensemble - Les Deux Lorraines : mazurkas pour deux clarinettes / G. Pihet ; Le Bal Champêtre lorrain dir. M. Antoine - L'Ajaccienne : Hymne napoléonien / J. F. Costa et F. X. Giacobini ; harmonis. et orch. de Fr. Menichetti ; Estudiantina Ajaccienne dir. Choeurs : M. Gillot - Bale Kastel Pol : marche de Saint-Pol de Léon / La Bagad Kastel Pol - Les Epouseux du Berry : bourrée / arrang. J. Vaissade ; Marcel Bernard, sa cabrette et son ensemble - Echo des Alpes : tyrolienne / F. Lacroix ; Gaby et Fernard Lacroix - Loa-Loa : Berceuse / Harm. Esnaola ; Chorale des Ballets Basques de Biarritz "Oldarra" - La Polka des cricris / folk. Arrang. P. Peau et J. Grossier ; Ménestrels de Gérardmer dir. J. GrossierBnF-Partenariats, Collection sonore - BelieveContient une table des matière
Conventional Methods for the Diagnosis of Dermatophytosis
No full textDermatophytes are keratinolytic fungi responsible for a large variety of diseases that can affect glabrous skin, nails and hair. In many cases, the diagnosis is not clinically obvious, and mycological analysis is required. This includes both direct microscopic examination and cultures. First of all, clinical specimens have to be sampled according to localization and characteristics of the lesions. Direct microscopic examination is usually performed using clearing reagents (KOH or Amman’s chloral-lactophenol), but its sensitivity may be greatly enhanced by the use of stains or fluorochromes such as Congo red or Calcofluor white. Histological analysis is an efficient method, but it is constraining for the patients and, as direct examination, it does not allow precise identification of the pathogen. Cultures are therefore needed, and specific culture media may be used to overcome the growth of rapidly growing contaminating moulds which may hamper the recovery of dermatophytes. Identification at the species level which may be useful to initiate an appropriate treatment or for setting prophylactic measures, relies on macroscopic and microscopic morphology. Subcultures on culture media which stimulate conidiation and, for some species, the production of pigments, are often necessary. Additionally, in case of atypical isolates, some biochemical or physiological tests may be performed such as the search for urease activity or the in vitro hair perforation test. However, their contribution to species identification is rather limited, and progress is still needed for the development of biochemical or immunological tests allowing an accurate identification at the species level, pending for the availability of molecular biology-based kits
Les dermatophytes : les difficultés du diagnostic mycologique
No full textRésuméLes dermatophytes sont des champignons filamenteux responsables de lésions variées de la peau et des phanères, dont le diagnostic n’est pas toujours évident cliniquement. Devant une lésion évoquant une dermatophytie, un examen mycologique s’impose donc le plus souvent. Cependant, bien que cette recherche soit d’usage courant dans les laboratoires d’analyses médicales, la mise en évidence d’une étiologie fongique n’est pas assurée pour autant. En effet, pour obtenir un résultat fiable, le biologiste doit surmonter plusieurs niveaux d’obstacles : 1. la réalisation du prélèvement selon le type de lésion, 2. l’examen direct des différents produits biologiques, ainsi que leur mise en culture, 3. l’identification des champignons isolés, 4. l’interprétation des résultats. Les difficultés susceptibles d’être rencontrées au cours des différentes étapes du diagnostic des dermatophyties reposent essentiellement sur l’absence de standardisation des prélèvements et des techniques mycologiques, ainsi que sur le manque de commercialisation de certains réactifs et milieux de culture. Les auteurs se proposent de passer en revue les principaux pièges à éviter
Les onychomycoses à moisissures
No full textOnychomycoses represent about 30% of superficial mycosis that are encountered in Dermatology consults. Fungi such as dermatophytes, which are mainly found on the feet nails, cause nearly 50% of these onychopathies. Yeasts are predominantly present on hands, whereas non-dermatophytic moulds are very seldom involved in both foot and hand nails infections. According to literature, these moulds are responsible for 2 to 17% of onychomycoses. Nevertheless, we have to differentiate between onychomycoses due to pseudodermatophytes such as Neoscytalidium (ex-Scytalidium) and Onychocola canadensis, which present a high affinity for keratin, and onychomycoses due to filamentous fungi such as Aspergillus, Fusarium, Scopulariopsis, Acremonium… These saprophytic moulds are indeed most of the time considered as colonizers rather than real pathogens agents. Mycology and histopathology laboratories play an important role. They allow to identify the species that is involved in nail infection, but also to confirm parasitism by the fungus in the infected nails. Indeed, before attributing any pathogenic role to non-dermatophytic moulds, it is essential to precisely evaluate their pathogenicity through samples and accurate mycological and/or histological analysis. The treatment of onychomycoses due to non-dermatophytic moulds is difficult, as there is today no consensus. The choice of an antifungal agent will first depend on the species that is involved in the infection, but also on the severity of nail lesions and on the patient himself. In most cases, the onychomycosis will be cured with chemical or mechanical removing of the infected tissues, followed by a local antifungal treatment. In some cases, a systemic therapy will be discussed
Diagnostic biologique des candidoses
No full textCandidiasis is the most common fungal infection in humans. Conventional techniques are usually sufficient for the diagnosis of superficial candidiasis. For deep-seated or systemic candidiasis, blood cultures still represent the “gold standard”, although their sensitivity can be overtaken. In recent decades, numerous alternative tests have been developed to overcome this lack of sensitivity. These techniques allow the detection of antibodies, antigens, metabolites or nucleic acids.
In most cases, serological results have to be interpretated according to the immune status of patients. Detection of antibodies alone is often poorly contributive to the diagnosis, except when this is associated with the detection of circulating antigens. Thus, the detection of circulating mannans is useful in the diagnosis of infections caused by the most frequent Candida species; the sensitivity of this test increases with the repetition of samplings and the joint detection of anti-mannan antibodies. Besides, detection of β(1.3)-D glucans, alone or in association with the detection of mannans, may be useful for early diagnosis of deep-seated candidiasis.
Molecular biology helps us to diagnose deep-seated candidiasis without referring to the patient\u27s immune status. With the newly commercialized kits, molecular detection of Candida should expand in laboratories. In the same way, proteomic analysis by MALDI-TOF allows to substantially shorten the time for identification of isolated yeasts.
Modern methods of molecular typing, which are based on the analysis of genome variability, replaced phenotypic techniques. Although insufficiently standardized, they represent a powerful tool to better understand the epidemiology of Candida infections
Méthodes de diagnostic d’une onychomycose
No full textOnychomycosis represents about 50% of ungueal pathology. Dermatophytes (especially Trichophyton rubrum and Trichophyton interdigitale) are the main species involved in tinea pedis. Yeasts of the Candida (Candida albicans, Candida parapsilosis,…) genus are predominant on hands and very often associated with ungueal disease and perionyxis. Fungi other than the classic dermatophytes and yeasts can be rarely isolated from nail diseases. Among them, species belonging to Scopulariopsis, Aspergillus and Fusarium genus are mainly found, but their involvement in the disease must be proved. Other fungi, presenting a special affinity to keratin (pseudodermatophytes), such as Neoscytalidium dimidiatum (ex Scytalidium dimidiatum) from tropical and subtropical areas and Onychocola canadensis from Northern America and Europe, are considered as real pathogens in nail diseases. A multidisciplinary approach, including clinicians and biologists, is required to confirm the mycosis. This comparative review emphasizes the importance of histological examination, as well as molecular approaches, which are very contributive to the diagnosis of onychomycosis. The role of the laboratory is to identify at the species level the fungus isolated from nail scrapings and to show its involvement in the ungueal lesions
Wavelength-shifting light traps for SWGO and other applications
No full textWavelength-shifting (WLS) materials contain molecules that absorb light and
reemit at longer wavelengths. They can be used for light detection because they
provide a large effective area for low cost and they are able to efficiently
trap and guide light because of total internal reflection processes. We are
currently developing such a WLS detector, considering two main designs: A
single-shift design with one wavelength shift (tile) and a double-shift design
with two wavelength shifts (tile and fiber). As photodetectors we use small
Silicon photomultipliers (SiPMs) with a high photon detection efficiency (PDE)
and single-photon sensitivity. The double-shift layout goes at the expense of
detection efficiency. In this design however, light is channeled to the two
ends of a fiber, thus requiring a reduced photosensitive area compared to the
single-shift layout. We will present the results of our measurements and show
that light traps and SiPMs together represent a promising alternative to PMTs
in case of a non-focused light beam. For the special case of SWGO, the
application of light traps is also motivated by a possible improvement of the
gamma/hadron separation, using a one-chamber tank with an array of
wavelength-shifting light traps instead of a (two-chamber) tank with PMTs.
Besides SWGO, new WLS detectors could also constitute useful and cheap
technology for other experiments and use cases. The contribution summarizes our
motivation and efforts to build a light trap detection module and to
characterize its properties in terms of costs, temporal performance and
detection efficiency.Comment: 8 pages, 9 figures, Presented at the 38th International Cosmic Ray
Conference (ICRC 2023), 202
- …
