Sound localization and word discrimination in reverberant environment in children with developmental dyslexia

Objective Compare if localization of sounds and words discrimination in reverberant environment is different between children with dyslexia and controls. Method We studied 30 children with dyslexia and 30 controls. Sound and word localization and discrimination was studied in five angles from left to right auditory fields (-90o, -45o, 0o, +45o, +90o), under reverberant and no-reverberant conditions; correct answers were compared. Results Spatial location of words in no-reverberant test was deficient in children with dyslexia at 0º and +90o. Spatial location for reverberant test was altered in children with dyslexia at all angles, except -90o. Word discrimination in no-reverberant test in children with dyslexia had a poor performance at left angles. In reverberant test, children with dyslexia exhibited deficiencies at -45o, -90o, and +45o angles. Conclusion Children with dyslexia could had problems when have to locate sound, and discriminate words in extreme locations of the horizontal plane in classrooms with reverberation

The kinetics of antibody binding to Plasmodium falciparum VAR2CSA PfEMP1 antigen and modelling of PfEMP1 antigen packing on the membrane knobs

<p>Abstract</p> <p>Background</p> <p>Infected humans make protective antibody responses to the PfEMP1 adhesion antigens exported by <it>Plasmodium falciparum </it>parasites to the erythrocyte membrane, but little is known about the kinetics of this antibody-receptor binding reaction or how the topology of PfEMP1 on the parasitized erythrocyte membrane influences antibody association with, and dissociation from, its antigenic target.</p> <p>Methods</p> <p>A Quartz Crystal Microbalance biosensor was used to measure the association and dissociation kinetics of VAR2CSA PfEMP1 binding to human monoclonal antibodies. Immuno-fluorescence microscopy was used to visualize antibody-mediated adhesion between the surfaces of live infected erythrocytes and atomic force microscopy was used to obtain higher resolution images of the membrane knobs on the infected erythrocyte to estimate knob surface areas and model VAR2CSA packing density on the knob.</p> <p>Results</p> <p>Kinetic analysis indicates that antibody dissociation from the VAR2CSA PfEMP1 antigen is extremely slow when there is a high avidity interaction. High avidity binding to PfEMP1 antigens on the surface of <it>P. falciparum</it>-infected erythrocytes in turn requires bivalent cross-linking of epitopes positioned within the distance that can be bridged by antibody. Calculations of the surface area of the knobs and the possible densities of PfEMP1 packing on the knobs indicate that high-avidity cross-linking antibody reactions are constrained by the architecture of the knobs and the large size of PfEMP1 molecules.</p> <p>Conclusions</p> <p>High avidity is required to achieve the strongest binding to VAR2CSA PfEMP1, but the structures that display PfEMP1 also tend to inhibit cross-linking between PfEMP1 antigens, by holding many binding epitopes at distances beyond the 15-18 nm sweep radius of an antibody. The large size of PfEMP1 will also constrain intra-knob cross-linking interactions. This analysis indicates that effective vaccines targeting the parasite's vulnerable adhesion receptors should primarily induce strongly adhering, high avidity antibodies whose association rate constant is less important than their dissociation rate constant.</p

ExoClock Project. III. 450 New Exoplanet Ephemerides from Ground and Space Observations

The ExoClock project has been created to increase the efficiency of the Ariel mission. It will achieve this by continuously monitoring and updating the ephemerides of Ariel candidates, in order to produce a consistent catalog of reliable and precise ephemerides. This work presents a homogenous catalog of updated ephemerides for 450 planets, generated by the integration of ∼18,000 data points from multiple sources. These sources include observations from ground-based telescopes (the ExoClock network and the Exoplanet Transit Database), midtime values from the literature, and light curves from space telescopes (Kepler, K2, and TESS). With all the above, we manage to collect observations for half of the postdiscovery years (median), with data that have a median uncertainty less than 1 minute. In comparison with the literature, the ephemerides generated by the project are more precise and less biased. More than 40% of the initial literature ephemerides had to be updated to reach the goals of the project, as they were either of low precision or drifting. Moreover, the integrated approach of the project enables both the monitoring of the majority of the Ariel candidates (95%), and also the identification of missing data. These results highlight the need for continuous monitoring to increase the observing coverage of the candidate planets. Finally, the extended observing coverage of planets allows us to detect trends (transit-timing variations) for a sample of 19 planets. All the products, data, and codes used in this work are open and accessible to the wider scientific community

Monitoring Toxic Ionic Liquids in Zebrafish (Danio rerio) with Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI-MSI)

National Science and Engineering Research CouncilAmbient mass spectrometry imaging has become an increasingly powerful technique for the direct analysis of biological tissues in the open environment with minimal sample preparation and fast analysis times. In this study, we introduce desorption electrospray ionization mass spectrometry imaging (DESI-MSI) as a novel, rapid, and sensitive approach to localize the accumulation of a mildly toxic ionic liquid (IL), AMMOENG 130 in zebrafish (Danio rerio). The work demonstrates that DESI-MSI has the potential to rapidly monitor the accumulation of IL pollutants in aquatic organisms. AMMOENG 130 is a quaternary ammonium-based IL reported to be broadly used as a surfactant in commercialized detergents. It is known to exhibit acute toxicity to zebrafish causing extensive damage to gill secondary lamellae and increasing membrane permeability. Zebrafish were exposed to the IL in a static 96-h exposure study in concentrations near the LC50 of 1.25, 2.5, and 5.0 mg/L. DESI-MS analysis of zebrafish gills demonstrated the appearance of a dealkylated AMMOENG 130 metabolite in the lowest concentration of exposure identified by a high resolution hybrid LTQ-Orbitrap mass spectrometer as the trimethylstearylammonium ion, [C21H46N](+). With DESI-MSI, the accumulation of AMMOENG 130 and its dealkylated metabolite in zebrafish tissue was found in the nervous and respiratory systems. AMMOENG 130 and the metabolite were capable of penetrating the blood brain barrier of the fish with significant accumulation in the brain. Hence, we report for the first time the simultaneous characterization, distribution, and metabolism of a toxic IL in whole body zebrafish analyzed by DESI-MSI. This ambient mass spectrometry imaging technique shows great promise for the direct analysis of biological tissues to qualitatively monitor foreign, toxic, and persistent compounds in aquatic organisms from the environment