369 research outputs found
Data reduction pipeline for MOF-based synoptic telescopes
There are strong scientific cases and practical reasons for building ground-based solar synoptic telescopes. Some issues, like the study of solar dynamics and the forecasting of solar flares, benefit from the 3D reconstruction of the Sun's atmosphere and magnetic field. Others, like the monitoring and prediction of space weather, require full disk observations, at the proper sampling rate, combining H-alpha images and Doppler velocity and magnetic field. The synoptic telescopes based on Magneto Optical Filters (MOF) using different lines are capable of measuring the line-of-sight Doppler velocity and magnetic field over the full solar disk at different ranges of height in the Sun's photosphere and low chromosphere. Instruments like the MOTH (Magneto-Optical filters at Two Heights), using a dual-channel based on MOFs operating at 589.0 nm (Na D2 line) and 769.9 nm (K D1 line), the VAMOS instrument (Velocity And Magnetic Observations of the Sun), operating at 769.9 nm (K D1 line), and the future TSST (Tor Vergata Synoptic Solar Telescope), using a dual-channel telescope operating at 656.28 nm (H-alpha line) and at 769.9 nm (K D1 line), allow to face both aspects, the scientific and the operative related to Space Weather applications. The MOTH, VAMOS and TSST data enable a wide variety of studies of the Sun, from seismic probing of the solar interior (sound speed, rotation, details of the tachocline, sub-surface structure of active regions), to the dynamics and magnetic evolution of the lower part of the solar atmosphere (heating of the solar atmosphere, identification of the signatures of solar eruptive events, atmospheric gravity waves, etc.), to the 3D reconstruction of the solar atmosphere and flare locations. However, the use of MOF filters requires special care in calibrating the data for scientific or operational use. This work presents a systematic pipeline that derives from the decennial use of MOF's technology. More in detail, the pipeline is based on data reduction procedures tested and validated on MOTH data acquired at Mees Solar Observatory of the University of Hawaii Haleakala Observatories and at South Pole Solar Observatory (SPSO), at the Amundsen-Scott South Pole Station in Antarctica, during Antarctica Summer Campaign 2016/17
Revisiting the B-cell compartment in mouse and humans: more than one B-cell subset exists in the marginal zone and beyond.
International audienceABSTRACT: The immunological roles of B-cells are being revealed as increasingly complex by functions that are largely beyond their commitment to differentiate into plasma cells and produce antibodies, the key molecular protagonists of innate immunity, and also by their compartmentalisation, a more recently acknowledged property of this immune cell category. For decades, B-cells have been recognised by their expression of an immunoglobulin that serves the function of an antigen receptor, which mediates intracellular signalling assisted by companion molecules. As such, B-cells were considered simple in their functioning compared to the other major type of immune cell, the T-lymphocytes, which comprise conventional T-lymphocyte subsets with seminal roles in homeostasis and pathology, and non-conventional T-lymphocyte subsets for which increasing knowledge is accumulating. Since the discovery that the B-cell family included two distinct categories - the non-conventional, or extrafollicular, B1 cells, that have mainly been characterised in the mouse; and the conventional, or lymph node type, B2 cells - plus the detailed description of the main B-cell regulator, FcγRIIb, and the function of CD40+ antigen presenting cells as committed/memory B-cells, progress in B-cell physiology has been slower than in other areas of immunology. Cellular and molecular tools have enabled the revival of innate immunity by allowing almost all aspects of cellular immunology to be re-visited. As such, B-cells were found to express "Pathogen Recognition Receptors" such as TLRs, and use them in concert with B-cell signalling during innate and adaptive immunity. An era of B-cell phenotypic and functional analysis thus began that encompassed the study of B-cell microanatomy principally in the lymph nodes, spleen and mucosae. The novel discovery of the differential localisation of B-cells with distinct phenotypes and functions revealed the compartmentalisation of B-cells. This review thus aims to describe novel findings regarding the B-cell compartments found in the mouse as a model organism, and in human physiology and pathology. It must be emphasised that some differences are noticeable between the mouse and human systems, thus increasing the complexity of B-cell compartmentalisation. Special attention will be given to the (lymph node and spleen) marginal zones, which represent major crossroads for B-cell types and functions and a challenge for understanding better the role of B-cell specificities in innate and adaptive immunology
Mesonic cloud contribution to the nucleon and delta masses
Pion-nucleon elastic scattering in the dominant channel is examined
in the model in which the interaction is of the form . New expressions are found for the elastic pion-nucleon
scattering amplitude which differ from existing formula both in the kinematics
and in the treatment of the renormalization of the nucleon mass and coupling
constant. Fitting the model to the phase shifts in the channel does
not uniquely fix the parameters of the model. The cutoff for the pion-nucleon
form factor is found to lie in the range MeV/c. The masses
of the nucleon and the which would arise if there were no coupling to
mesons are found to be MeV and MeV. The difference in these bare masses, a quantity which would
be accounted for by a residual gluon interaction, is found to be MeV.Comment: 26 pages, 9 figures, significant rewrit
Directional sideward emission from luminescent plasmonic nanostructures
Periodic arrays of metallic nanoparticles can be used to enhance the emission of light in certain directions. We fabricated hexagonal arrays of aluminium nanoparticles combined with thin layers of luminescent material and optimized period (275 nm) and thickness (1500 nm) to obtain sideward directional emission into glass for a wavelength band around 620 nm. The key physics is that the luminescent layer acts as a waveguide, from which light is emitted at preferential angles using diffractive effects. This phenomenon has applications in the field of solid-state lighting, where there is a desire for small, bright and directional sources
The Role of Inflammatory Mediators in the Pathogenesis of Otitis Media and Sequelae
This review deals with the characteristics of various inflammatory mediators identified in the middle ear during otitis media and in cholesteatoma. The role of each inflammatory mediator in the pathogenesis of otitis media and cholesteatoma has been discussed. Further, the relation of each inflammatory mediator to the pathophysiology of the middle and inner ear along with its mechanisms of pathological change has been described. The mechanisms of hearing loss including sensorineural hearing loss (SNHL) as a sequela of otitis media are also discussed. The passage of inflammatory mediators through the round window membrane into the scala tympani is indicated. In an experimental animal model, an application of cytokines and lipopolysaccharide (LPS), a bacterial toxin, on the round window membrane induced sensorineural hearing loss as identified through auditory brainstem response threshold shifts. An increase in permeability of the blood-labyrinth barrier (BLB) was observed following application of these inflammatory mediators and LPS. The leakage of the blood components into the lateral wall of the cochlea through an increase in BLB permeability appears to be related to the sensorineural hearing loss by hindering K+ recycling through the lateral wall disrupting the ion homeostasis of the endolymph. Further studies on the roles of various inflammatory mediators and bacterial toxins in inducing the sensorineumral hearing loss in otitis media should be pursued
Macroscopic description of the external and middle ear of paca (Cuniculus paca Linnaeus, 1766)
Abstract: Paca (Cuniculus paca), one of the largest rodents of the Brazilian fauna, has inherent characteristics of its species which can conribute as a new option for animal experimantation. As there is a growing demand for suitable experimental models in audiologic and otologic surgical research, the gross anatomy and ultrastructural ear of this rodent have been analyzed and described in detail. Fifteen adult pacas from the Wild Animals Sector herd of Faculdade de Ciências Agrárias e Veterinárias, Unesp-Jaboticabal, were used in this study. After anesthesia and euthanasia, we evaluated the entire composition of the external ear, registering and ddescribing the details; the temporal region was often dissected for a better view and detailing of the tympanic bulla which was removed and opened to expose the ear structures analyzed mascroscopically and ultrastructurally. The ear pinna has a triangular and concave shape with irregular ridges and sharp apex. The external auditory canal is winding in its path to the tympanic mebrane. The tympanic bulla is is on the back-bottom of the skull. The middle ear is formed by a cavity region filled with bone and membranous structures bounded by the tympanic membrane and the oval and round windows. The tympanic membrane is flat and seals the ear canal. The anatomy of the paca ear is similar to the guinea pig and from the viewpoint of experimental model has major advantages compared with the mouse ear
Design Rules for Charge-Transport Efficient Host Materials for Phosphorescent Organic Light-Emitting Diodes
Microbiology of Serous Otitis Media in Children: Correlation with Age and Length of Effusion
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