Search results for " Structure"
showing 10 items of 25475 documents
The Extracellular δ-Domain is Essential for the Formation of CD81 Tetraspanin Webs
2014
AbstractCD81 is a ubiquitously expressed member of the tetraspanin family. It forms large molecular platforms, so-called tetraspanin webs that play physiological roles in a variety of cellular functions and are involved in viral and parasite infections. We have investigated which part of the CD81 molecule is required for the formation of domains in the cell membranes of T-cells and hepatocytes. Surprisingly, we find that large CD81 platforms assemble via the short extracellular δ-domain, independent from a strong primary partner binding and from weak interactions mediated by palmitoylation. The δ-domain is also essential for the platforms to function during viral entry. We propose that, ins…
Estrabismo y visión binocular tras cirugía refractiva
2018
ANTECEDENTES: La cirugía refractiva ha demostrado ser segura y efectiva para la corrección de errores de refracción y estrabismos puramente acomodativos. Sin embargo, alteraciones sensoriomotoras como descompensación de estrabismos, aparición de diplopía y supresión son complicaciones también descritas tras la cirugía refractiva. OBJETIVOS: El objetivo principal fue evaluar los efectos en la alineación ocular y en la visión binocular, en términos de fusión y estereopsis, en pacientes sometidos a cirugía refractiva mediante técnicas tanto ablativas corneales como intraoculares. Los objetivos secundarios fueron determinar la prevalencia de alteraciones en la visión binocular y el alineamiento…
Anatomic and functional follow-up of patients with an idiopathic epiretinal membrane and a preserved visual acuity
2013
Purpose: To determine the anatomic and functional retinal modifications in patients with an idiopathic epiretinal membrane (ERM) and a preserved visual acuity (VA).Methods: Monocentric, prospective study in 24 eyes of 24 patients with an ERM and a VA better than 20/25. Recorded data were best corrected VA on ETDRS scale, retinal anatomic lesions on spectral-domain OCT, retinal sensitivities on microperimetry and macular and foveal thicknesses at 0 and 6 months.Results: At inclusion, mean VA was 84 ± 5 letters, mean macular sensitivity was 14.0 ± 1.4 decibels (dB) and mean foveal sensitivity was 14,4 ± 1,5 dB. Mean macular thickness was 351 ± 34 µm and mean foveal thickness was 348 ± 66 µm. …
Motion perception in early glaucoma
2013
Purpose: The aim of our study was to underline the changes in the movement perception for early glaucoma. Our working hypothesis consisted in inquiring if the impairment of the magnocellular pathway may modify the movement perception capabilities in the visual field, more particularly in its peripheral area.Methods: We included 14 healthy subjects and 14 patients with early primary open angle glaucoma. A moving target was presented on a semicircular screen (1.8 m diameter); participants were asked to localize the Ending Point (EP) of each movement. Each stimulus consisted in a white dot (0,72° of diameter) moving horizontally with the imposed velocity profile. Two different laws of motion w…
Event-related potentials to task-irrelevant changes in facial expressions
2009
Abstract Background Numerous previous experiments have used oddball paradigm to study change detection. This paradigm is applied here to study change detection of facial expressions in a context which demands abstraction of the emotional expression-related facial features among other changing facial features. Methods Event-related potentials (ERPs) were recorded in adult humans engaged in a demanding auditory task. In an oddball paradigm, repeated pictures of faces with a neutral expression ('standard', p = .9) were rarely replaced by pictures with a fearful ('fearful deviant', p = .05) or happy ('happy deviant', p = .05) expression. Importantly, facial identities changed from picture to pi…
Explicit behavioral detection of visual changes develops without their implicit neurophysiological detectability
2011
Change blindness is a failure of reporting major changes across consecutive images if separated, e.g., by a brief blank interval. Successful change detection across interrupts requires focal attention to the changes. However, findings of implicit detection of visual changes during change blindness have raised the question of whether the implicit mode is necessary for development of the explicit mode. To this end, we recorded the visual mismatch negativity (vMMN) of the event-related potentials (ERPs) of the brain, an index of implicit pre-attentive visual change detection, in adult humans performing an oddball-variant of change blindness flicker task. Images of 500 ms in duration were prese…
Long-term physical activity modifies automatic visual processing
2019
Electrophysiologically registered visual mismatch negativity (vMMN) is known to represent automatic visual processing in human visual cortex. Since physical activity (PA) is generally beneficial to cerebrovascular function, we wanted to find out if automatic visual processing is affected by PA. We investigated the connection between long-term leisure-time PA and precognitive visual processing in 32 healthy young males. Participants were divided into active (n = 16) and inactive (n = 16) group according to their leisure-time PA records from the past three years. vMMN was recorded with electroencephalogram using passive oddball paradigm with visual bars. Standard (90%) and deviant (10%) stimu…
Scleral Buckling: A Review of Clinical Aspects and Current Concepts
2021
Scleral buckling represents a valuable treatment option for rhegmatogenous retinal detachment repair. The surgery is based on two main principles: the closure of retinal breaks and the creation of a long-lasting chorioretinal adhesion. Buckles are placed onto the sclera with the purpose of sealing retinal breaks. Cryopexy is usually performed to ensure a long-lasting chorioretinal adhesion. Clinical outcomes of scleral buckling have been shown to be more favorable in phakic eyes with uncomplicated or medium complexity retinal detachment, yielding better anatomical and functional results compared with vitrectomy. Several complications have been described following scleral buckling surgery, s…
Emission of Bromine and Iodine from Mt. Etna volcano
2005
Constraining fluxes of volcanic bromine and iodine to the atmosphere is important given the significant role these species play in ozone depletion. However, very few such measurements have been made hitherto, such that global volcanic fluxes are poorly constrained. Here we extend the data set of volcanic Br and I degassing by reporting the first measurements of bromine and iodine emissions from Mount Etna. These data were obtained using filter packs and contemporaneous ultraviolet spectroscopic SO2 flux measurements, resulting in time-averaged emission rates of 0.7 kt yr(-1) and 0.01 kt yr(-1) for Br and I, respectively, from April to October 2004, from which we estimate global Br and I flu…
Seeing red? Colour biases of foraging birds are context dependent.
2020
Funder: Suomen Kulttuurirahasto; doi: http://dx.doi.org/10.13039/501100003125