60 research outputs found

    A right hemisphere advantage for processing blurred faces

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    Functional Magnetic Resonance Imaging

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    "Functional Magnetic Resonance Imaging - Advanced Neuroimaging Applications" is a concise book on applied methods of fMRI used in assessment of cognitive functions in brain and neuropsychological evaluation using motor-sensory activities, language, orthographic disabilities in children. The book will serve the purpose of applied neuropsychological evaluation methods in neuropsychological research projects, as well as relatively experienced psychologists and neuroscientists. Chapters are arranged in the order of basic concepts of fMRI and physiological basis of fMRI after event-related stimulus in first two chapters followed by new concepts of fMRI applied in constraint-induced movement therapy; reliability analysis; refractory SMA epilepsy; consciousness states; rule-guided behavioral analysis; orthographic frequency neighbor analysis for phonological activation; and quantitative multimodal spectroscopic fMRI to evaluate different neuropsychological states

    Pre-processing, classification and semantic querying of large-scale Earth observation spaceborne/airborne/terrestrial image databases: Process and product innovations.

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    By definition of Wikipedia, “big data is the term adopted for a collection of data sets so large and complex that it becomes difficult to process using on-hand database management tools or traditional data processing applications. The big data challenges typically include capture, curation, storage, search, sharing, transfer, analysis and visualization”. Proposed by the intergovernmental Group on Earth Observations (GEO), the visionary goal of the Global Earth Observation System of Systems (GEOSS) implementation plan for years 2005-2015 is systematic transformation of multisource Earth Observation (EO) “big data” into timely, comprehensive and operational EO value-adding products and services, submitted to the GEO Quality Assurance Framework for Earth Observation (QA4EO) calibration/validation (Cal/Val) requirements. To date the GEOSS mission cannot be considered fulfilled by the remote sensing (RS) community. This is tantamount to saying that past and existing EO image understanding systems (EO-IUSs) have been outpaced by the rate of collection of EO sensory big data, whose quality and quantity are ever-increasing. This true-fact is supported by several observations. For example, no European Space Agency (ESA) EO Level 2 product has ever been systematically generated at the ground segment. By definition, an ESA EO Level 2 product comprises a single-date multi-spectral (MS) image radiometrically calibrated into surface reflectance (SURF) values corrected for geometric, atmospheric, adjacency and topographic effects, stacked with its data-derived scene classification map (SCM), whose thematic legend is general-purpose, user- and application-independent and includes quality layers, such as cloud and cloud-shadow. Since no GEOSS exists to date, present EO content-based image retrieval (CBIR) systems lack EO image understanding capabilities. Hence, no semantic CBIR (SCBIR) system exists to date either, where semantic querying is synonym of semantics-enabled knowledge/information discovery in multi-source big image databases. In set theory, if set A is a strict superset of (or strictly includes) set B, then A B. This doctoral project moved from the working hypothesis that SCBIR computer vision (CV), where vision is synonym of scene-from-image reconstruction and understanding EO image understanding (EO-IU) in operating mode, synonym of GEOSS ESA EO Level 2 product human vision. Meaning that necessary not sufficient pre-condition for SCBIR is CV in operating mode, this working hypothesis has two corollaries. First, human visual perception, encompassing well-known visual illusions such as Mach bands illusion, acts as lower bound of CV within the multi-disciplinary domain of cognitive science, i.e., CV is conditioned to include a computational model of human vision. Second, a necessary not sufficient pre-condition for a yet-unfulfilled GEOSS development is systematic generation at the ground segment of ESA EO Level 2 product. Starting from this working hypothesis the overarching goal of this doctoral project was to contribute in research and technical development (R&D) toward filling an analytic and pragmatic information gap from EO big sensory data to EO value-adding information products and services. This R&D objective was conceived to be twofold. First, to develop an original EO-IUS in operating mode, synonym of GEOSS, capable of systematic ESA EO Level 2 product generation from multi-source EO imagery. EO imaging sources vary in terms of: (i) platform, either spaceborne, airborne or terrestrial, (ii) imaging sensor, either: (a) optical, encompassing radiometrically calibrated or uncalibrated images, panchromatic or color images, either true- or false color red-green-blue (RGB), multi-spectral (MS), super-spectral (SS) or hyper-spectral (HS) images, featuring spatial resolution from low (> 1km) to very high (< 1m), or (b) synthetic aperture radar (SAR), specifically, bi-temporal RGB SAR imagery. The second R&D objective was to design and develop a prototypical implementation of an integrated closed-loop EO-IU for semantic querying (EO-IU4SQ) system as a GEOSS proof-of-concept in support of SCBIR. The proposed closed-loop EO-IU4SQ system prototype consists of two subsystems for incremental learning. A primary (dominant, necessary not sufficient) hybrid (combined deductive/top-down/physical model-based and inductive/bottom-up/statistical model-based) feedback EO-IU subsystem in operating mode requires no human-machine interaction to automatically transform in linear time a single-date MS image into an ESA EO Level 2 product as initial condition. A secondary (dependent) hybrid feedback EO Semantic Querying (EO-SQ) subsystem is provided with a graphic user interface (GUI) to streamline human-machine interaction in support of spatiotemporal EO big data analytics and SCBIR operations. EO information products generated as output by the closed-loop EO-IU4SQ system monotonically increase their value-added with closed-loop iterations

    Aerospace Medicine and Biology: A continuing bibliography (supplement 249)

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    This bibliography lists 311 reports, articles and other documents introduced into the NASA scientific and technical information system in August 1983

    Glaucoma

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    This book addresses the basic and clinical science of glaucomas, a group of diseases that affect the optic nerve and visual fields and is usually accompanied by increased intraocular pressure. The book incorporates the latest development as well as future perspectives in glaucoma, since it has expedited publication. It is aimed for specialists in glaucoma, researchers, general ophthalmologists and trainees to increase knowledge and encourage further progress in understanding and managing these complicated diseases

    The development of a clinical trial protocol and functional biomarkers for age-related macular degeneration

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    Age-related macular degeneration (AMD) is the leading cause of blindness amongst older adults in the developed world. With the predicted rise in the ageing population over the next decades, the prevalence of this debilitating disease will simply continue to increase. The only treatments currently available are for advanced neovascular AMD. The retina is already severely compromised by this stage in disease development. Therefore, there is a pressing need to evaluate potential novel interventions that aim to prevent the development of advanced disease in people with early AMD, to prevent sight loss from occurring. Furthermore, it is necessary to develop tests that are sensitive to subtle changes in visual function in order to evaluate the efficacy of these emerging treatments. There is a growing body of evidence to suggest that hypoxia contributes to the development of AMD. Hypoxia is most acute at night when the retinal photoreceptors are most metabolically active, due to the demands of the rod dark current. Increasing the light levels at night will cause the oxygen demand, and hence the hypoxia, to be substantially diminished. This leads to the hypothesis that providing low level night time light therapy to people with early AMD may slow disease progression by reducing hypoxia. In order to evaluate the potential effectiveness of such an intervention, it is necessary to select appropriate outcome measures. The inherent variability of the standard test of visual function, visual acuity, renders it inappropriate for use as a primary outcome measure in proof of concept clinical trials. Therefore, the first aim of this thesis was to evaluate the diagnostic validity and repeatability of alternative functional tests that may be used as biomarkers for early macular disease. Dark adaptation was evaluated using three stimuli, a spot of 2o radius and annuli of 7o and 12o radii, in 21 healthy adults (on two occasions) and in 11 participants with early AMD. All stimuli were found to be highly diagnostic for early AMD. The spot of 2o radius provided the best separation between groups with respect to the time constant of cone recovery (area under the ROC curve 0.91). The repeatability of chromatic and flicker thresholds were also assessed in 30 healthy adults. The coefficient of repeatability, expressed as a percentage of the mean threshold, was 17.1% for red-green chromatic thresholds, 31.1% for blue-yellow, 53.4% for 14Hz flicker thresholds, and ranged between 36.4%-53.3% for parameters of dark adaptation. A small learning effect was found for both chromatic thresholds and the 14-Hz flicker test, indicating that a control group is needed in studies of new therapeutic interventions. The second aim of this thesis was to develop a protocol for a clinical trial that seeks to determine if low level night time light therapy can prevent the progression of early AMD. The level of retinal illuminance required to suppress the rod dark current, the maximum retinal illuminance which prevents substantial suppression of melatonin secretion, and the most appropriate means of delivering the dose of retinal illumination were evaluated. The final protocol employed an organic LED illuminated light mask, worn during hours of sleep, as the mode of intervention. In conclusion, this thesis has confirmed that cone dark adaptation is a sensitive functional biomarker for AMD, and that all three functional tests have a good inter-session repeatability. These biomarkers will be validated in the prospective clinical trial of low-level light therapy to confirm their prognostic and predictive capabilities. The proposed trial will also evaluate the effectiveness of the low level night time light therapy, delivered by means of an illuminated light mask, at slowing the progression of early AMD

    Problem space of modern society: philosophical-communicative and pedagogical interpretations. Part I

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    This collective monograph offers the description of philosophical bases of definition of communicative competence and pedagogical conditions for the formation of communication skills. The authors of individual chapters have chosen such point of view for the topic which they considered as the most important and specific for their field of study using the methods of logical and semantic analysis of concepts, the method of reflection, textual reconstruction and comparative analysis. The theoretical and applied problems of modern society are investigated in the context of philosophical, communicative and pedagogical interpretations

    RÎle de deux groupes de vésicules dans la transmission synaptique

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    Les synapses formĂ©es par les fibres moussues (FM) sur les cellules principales de la rĂ©gion CA3 (FM-CA3) jouent un rĂŽle crucial pour la formation de la mĂ©moire spatiale dans l’hippocampe. Une caractĂ©ristique des FM est la grande quantitĂ© de zinc localisĂ©e avec le glutamate dans les vĂ©sicules synaptiques recyclĂ©es par la voie d’endocytose dĂ©pendante de l’AP3. En combinant l’imagerie calcique et l’électrophysiologie, nous avons Ă©tudiĂ© le rĂŽle des vĂ©sicules contenant le zinc dans la neurotransmission aux synapses FM-CA3. Contrairement aux Ă©tudes prĂ©cĂ©dentes, nous n’avons pas observĂ© de rĂŽle pour le zinc dans l’induction des vagues calciques. Nos expĂ©riences ont rĂ©vĂ©lĂ© que les vagues calciques sont dĂ©pendantes de l’activation des rĂ©cepteurs mĂ©tabotropiques et ionotropiques du glutamate. D’autre part, nos donnĂ©es indiquent que les vĂ©sicules dĂ©rivĂ©es de la voie dĂ©pendante de l’AP3 forment un groupe de vĂ©sicules possĂ©dant des propriĂ©tĂ©s spĂ©cifiques. Elles contribuent principalement au relĂąchement asynchrone du glutamate. Ainsi, les cellules principales du CA3 de souris n’exprimant pas la protĂ©ine AP3 avaient une probabilitĂ© infĂ©rieure de dĂ©charge et une rĂ©duction de la synchronie des potentiels d’action lors de la stimulation Ă  frĂ©quences physiologiques. Cette diminution de la synchronie n’était pas associĂ©e avec un changement des paramĂštres quantiques ou de la taille des groupes de vĂ©sicules. Ces rĂ©sultats supportent l’hypothĂšse que deux groupes de vĂ©sicules sont prĂ©sents dans le mĂȘme bouton synaptique. Le premier groupe est composĂ© de vĂ©sicules recyclĂ©es par la voie d’endocytose utilisant la clathrine et participe au relĂąchement synchrone du glutamate. Le second groupe est constituĂ© de vĂ©sicules ayant Ă©tĂ© recyclĂ©es par la voie d’endocytose dĂ©pendante de l’AP3 et contribue au relĂąchement asynchrone du glutamate. Ces deux groupes de vĂ©sicules sont nĂ©cessaires pour l’encodage de l’information et pourraient ĂȘtre importants pour la formation de la mĂ©moire. Ainsi, les dĂ©charges de courte durĂ©e Ă  haute frĂ©quence observĂ©es lorsque les animaux pĂ©nĂštrent dans les places fields pourraient causer le relĂąchement asynchrone de glutamate. Finalement, les rĂ©sultats de mon projet de doctorat valident l’existence et l’importance de deux groupes de vĂ©sicules dans les MF qui sont recyclĂ©es par des voies d’endocytoses distinctes et relĂąchĂ©es durant diffĂ©rents types d’activitĂ©s.Mossy fiber-CA3 pyramidal cell synapses play a crucial role in the hippocampal formation of spatial memories. These synaptic connections possess a number of unique features substantial for its role in the information processing and coding. One of these features is presence of zinc co-localized with glutamate within a subpopulation of synaptic vesicles recycling through AP3-dependent bulk endocytosis. Using Ca2+ imaging and electrophysiological recordings we investigated role of these zinc containing vesicles in the neurotransmission. In contrast to previous reports, we did not observe any significant role of vesicular zinc in the induction of large postsynaptic Ca2+ waves triggered by burst stimulation. Moreover, our experiments revealed that Ca2+ waves mediated by Ca2+ release from internal stores are dependent not only on the activation of metabotropic, but also ionotropic glutamate receptors. Nevertheless, subsequent experiments unveiled that the vesicles derived via AP3-dependent endocytosis primary contribute to the asynchronous, but not synchronous mode of glutamate release. Futhermore, knockout mice lacking adaptor protein AP3 had a reduced synchronization of postsynaptic action potentials and impaired information transfer; this was not associated with any changes in the synchronous release quantal parameters and vesicle pool size. These findings strongly support the idea that within a single presynaptic bouton two heterogeneous pools of releasable vesicles are present. One pool of readily releasable vesicles forms via clathrin mediated endocytosis and mainly participates in the synchronous release; a second pool forms through bulk endocytosis and primarily supplies asynchronous release. The existence of two specialized pools is essential for the information coding and transfer within hippocampus. It also might be important for hippocampal memory formation. In contrast to low firing rates at rest, dentate gyrus granule cells tend to fire high frequency bursts once an animal enters a place field. These burst activities, embedded in the lower gamma frequency, should be especially efficient in the triggering of substantial asynchronous glutamate release. Therefore, the results of my PhD project for the first time provide strong evidence for the presence and physiological importance of two vesicle pools with heterogeneous release and recycling properties via separate endocytic pathways within the same mossy fiber bouton

    Timing and Time Perception: Procedures, Measures, and Applications

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    Timing and Time Perception: Procedures, Measures, and Applications is a one-of-a-kind, collective effort to present the most utilized and known methods on timing and time perception. Specifically, it covers methods and analysis on circadian timing, synchrony perception, reaction/response time, time estimation, and alternative methods for clinical/developmental research. The book includes experimental protocols, programming code, and sample results and the content ranges from very introductory to more advanced so as to cover the needs of both junior and senior researchers. We hope that this will be the first step in future efforts to document experimental methods and analysis both in a theoretical and in a practical manner
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