872 research outputs found
Dissecting the phosphoproteome of the dag-dependent signaling pathway in reponse to antigen presentation
Comunicaciones a congreso
Validation d’une méthode de dénombrement de la concentration en cellules somatiques du lait de vache au moyen du Coulter Counter® modèle Z2
Depuis longtemps utilisé pour le suivi sanitaire et la gestion technique des troupeaux
laitiers, le résultat du comptage cellulaire de tank et donc indirectement du comptage
cellulaire individuel est devenu un critère officiel pour le paiement du lait et le contrôle laitier.
L’étude est consacrée à l’évaluation d’un compteur à particules : le Coulter Counter® modèle
Z2. Après calibrage primaire et étalonnage de l’appareil, une évaluation de ses performances
a été réalisée par la détermination de la justesse, de la fidélité et des critères d’appréciation
des analyses sur des échantillons de laits de quartiers.
Pour l’appréciation de la justesse, les échantillons de lait ont été dénombrés au préalable par
numération microscopique selon la méthode de Prescott et Breed (1910). Les résultats obtenus
ont révélé une bonne corrélation (CC = 0,94) avec un coefficient de variation de 3,17 %.
La fidélité, évaluée sur la base de la répétabilité (0,2 %) et de la reproductibilité (0,8 %) est
de 1 %. Ces valeurs sont nettement inférieures aux normes préconisées par la Fédération
Internationale de Laiterie (1995). La valeur diagnostique du matériel utilisé se trouve confirmée
par les valeurs de 0,96 et 0,87 % obtenues respectivement pour la sensibilité et la spécificité.
La confirmation de la qualité du matériel employé laisse entrevoir son utilisation possible Ã
large échelle dans la Wilaya de Blida. À ce titre il constitue un outil irremplaçable de contrôle
de la qualité et de valorisation du lait.Peer reviewe
Analysis of optical filtering in waveguides with a high index modulation using the extended coupled mode theory by hybridization of a matrix method
International audienceIn this paper the authors present an hybrid approach for the analysis of the optical filtering function in corrugated waveguide filters with a high index modulation. This approach is based on the hybridization of the extended couple mode theory (CMT) with the transfer matrix approach. The authors chose to treat the case of high index corrugation because in this case the theory elaborated before is not rigorously applicable. The proposed approach allows the calculation of the reflection coefficient and the full width at half maximum (FWHM) for any index modulation scheme. The hybridization of both methods mentioned above explains the impact and effects of opto-geometric parameters on the reflection coefficient and the bandwidth at mid-height. The theoretical results are verified by experimental measurements realized on Ti:LiNbO3 waveguides with a high index modulation experimentally implemented by engraving using Focused Ion Beam (FIB) process
Effective Dose and Size Specific Dose Estimation with and without Tube Current Modulation for Thoracic Computed Tomography Examinations: A Phantom Study
The purpose of this study is to reduce radiation dose for chest CT examination by including Tube Current Modulation (TCM) to a standard CT protocol. A scan of an anthropomorphic male Alderson phantom was performed on a 128-slice scanner. The estimation of effective dose (ED) in both scans with and without mAs modulation was done via multiplication of Dose Length Product (DLP) to a conversion factor. Results were compared to those measured with a CT-Expo software. The size specific dose estimation (SSDE) values were obtained by multiplication of the volume CT dose index (CTDIvol) with a conversion size factor related to the phantom’s effective diameter. Objective assessment of image quality was performed with Signal to Noise Ratio (SNR) measurements in phantom. SPSS software was used for data analysis. Results showed including CARE Dose 4D; ED was lowered by 48.35% and 51.51% using DLP and CT-expo, respectively. In addition, ED ranges between 7.01 mSv and 6.6 mSv in case of standard protocol, while it ranges between 3.62 mSv and 3.2 mSv with TCM. Similar results are found for SSDE; dose was higher without TCM of 16.25 mGy and was lower by 48.8% including TCM. The SNR values calculated were significantly different (p=0.03<0.05). The highest one is measured on images acquired with TCM and reconstructed with Filtered back projection (FBP). In conclusion, this study proves the potential of TCM technique in SSDE and ED reduction and in conserving image quality with high diagnostic reference level for thoracic CT examinations
Topological defects at smectic interfaces as a potential tool for the biosensing of living microorganisms
Characterizing the anchoring properties of smectic liquid crystals (LCs) in
contact with bacterial solutions is crucial for developing biosensing
platforms. In this study, we investigate the anchoring properties of a smectic
LC when exposed to Bacillus Subtilis and Escherichia coli bacterial solutions
using interfaces with known anchoring properties. By monitoring the optical
response of the smectic film, we successfully distinguish different types of
bacteria, leveraging the distinct changes in the LC's response. Through a
comprehensive analysis of the interactions between bacterial proteins and the
smectic interface, we elucidate the potential underlying mechanisms responsible
for these optical changes. Additionally, we introduce the utilization of
topological defects; the focal conic domains (FCDs), at the smectic interface
as an indicative measure of the bacterial concentration. Our findings
demonstrate the significant potential of smectic LCs and their defects for
biosensing applications and contribute to our understanding of bacteria- LC
interactions, paving the way for advancements in pathogen detection and
protein-based sensing
Manifestations Orl du Rgo chez l’enfant quelle attitude observer ?
Si les manifestations digestives ou respiratoires du reflux gastro-oesophagien sont connues depuis longtemps, la notion de pathologies ORL chroniques ou récidivantes liées au reflux est relativement récente et reste sujette à controverse. A travers une revue de la littérature récente, nous avons tenté de mettre en évidence un lien de causalité entre RGO et manifestations extra digestives, en particulier ORL, et d’en déduire une ligne de conduite thérapeutique.Mots Clés : RGO, Manifestations extra digestives, Pathologie ORL, Traitement médicamenteux, Traitement chirurgical, Traitement coelioscopique
Infection of Ixodes ricinus (Acari: Ixodidae) by Borrelia burgdorferi sensu lato in North Africa
Free-living adult Ixodes ricinus L. were collected in Amdoun, situated in the Kroumiry mountains in northwestern Tunisia (North Africa). Using direct fluorescence antibody assay, the infection rate of field-collected I. ricinus by Borrelia burgdorferi sensu lato was 30.5% (n = 72). No difference in infection rate was observed between male and female ticks. Spirochetes that had been isolated from I. ricinus from Ain Drahim (Kroumiry Mountains) in 1988 were identified as Borrelia lusitaniae (formerly genospecies PotiB2). This is the first identification of a genospecies of Borrelia burgdorferi sensu lato from the continent of Afric
Preliminary results of a paleoseismological analysis along the Sahel fault (Algeria): New evidence for historical seismic events
International audienceThe ∼60 km-long Sahel ridge west of Algiers (Tell Atlas, north Algeria) is considered as an ENE-WSW fault-propagation fold running along the Mediterranean coast and associated with a north-west dipping thrust. Its proximity with Algiers makes this structure a potential source of destructive earthquakes that could hit the capital city, as occurred in 1365 AD and 1716 AD. The first paleoseismologic investigation on the Sahel ridge was conducted in order to detect paleo-ruptures related to active faulting and to date them. From the first investigations in the area, a first trench was excavated across bending-moment normal faults induced by flexural slip folding in the hanging wall of the Sahel anticline thrust ramp. Paleoseismological analyses recognize eight rupture events affecting colluvial deposits. 14C dating indicates that these events are very young, six of them being younger than 778 AD. The first sedimentary record indicates two ruptures before 1211 AD, i.e. older than the first historical earthquake documented in the region. Three events have age ranges compatible with the 1365, 1673 and 1716 Algiers earthquakes, whereas three other ones depict very recent ages, i.e. younger than 1700 AD. Potential of these secondary extrados faults for determining paleoseismic events and thrust behaviour is discussed
Submersed Micropatterned Structures Control Active Nematic Flow, Topology and Concentration
Coupling between flows and material properties imbues rheological matter with
its wide-ranging applicability, hence the excitement for harnessing the
rheology of active fluids for which internal structure and continuous energy
injection lead to spontaneous flows and complex, out-of-equilibrium dynamics.
We propose and demonstrate a convenient, highly tuneable method for controlling
flow, topology and composition within active films. Our approach establishes
rheological coupling via the indirect presence of fully submersed
micropatterned structures within a thin, underlying oil layer. Simulations
reveal that micropatterned structures produce effective virtual boundaries
within the superjacent active nematic film due to differences in viscous
dissipation as a function of depth. This accessible method of applying
position-dependent, effective dissipation to the active films presents a
non-intrusive pathway for engineering active microfluidic systems.Comment: 13 pages; 5 main-text-figures; 3-supplemental-figure
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