169,777 research outputs found
Alteracions neurofisiològiques en el processament complex auditiu subjacents a patologies del llenguatge: disfèmia verbal i dislèxia del desenvolupament
No full text[cat] La present tesi doctoral consta de tres estudis sobre les alteracions neurofisiològiques en el processament auditiu subjacents a dues patologies del llenguatge del desenvolupament: la disfèmia verbal i la dislèxia. Aquests estudis s'han portat a terme mitjançant el registre de potencials evocats cerebrals (PECs). El primer estudi investigà les possibles alteracions auditives en la disfèmia del desenvolupament persistent, utilitzant el potencial evocat de disparitat (Mismatch Negativity, MMN). Els resultats mostraren l'existència d'un dèficit de processament auditiu específic dels estímuls de la parla manifestat per diferències entre el grup de disfèmics i els controls en l'amplitud del generador supratemporal esquerre del PEC auditiu MMN. A més, es trobà una correlació negativa entre el grau de fluïdesa de la parla i l'amplitud del generador supratemporal esquerre de MMN. Amb tot, aquest estudi mostrà que els disfèmics del desenvolupament persistent presenten alteracions específiques en el processament auditiu dels estímuls de la parla. El segon estudi investigà les possibles alteracions auditives en la dislèxia del desenvolupament, utilitzant el potencial MMN. Els resultats d'aquest estudi mostraren una demora en la latència del potencial MMN davant de contrastos auditius simples i també davant d'estímuls de la parla, és a dir, fonemes. A més, els resultats van revelar en els dislèctics l'existència d'alteracions en la discriminació temporal dels estímuls, manifestat per les diferències d'amplitud en el component MMN i del subseqüent component P3a trobades entre grups davant contrastos auditius de durada. Així doncs, els resultats d'aquest estudi revelaren que els subjectes amb dislèxia del desenvolupament presenten un dèficit específic de processament de la informació temporal auditiva. El tercer estudi investigà les possibles alteracions atencionals auditives en la dislèxia del desenvolupament, utilitzant el potencial evocat P3a o novelty-P3. Aquest estudi es va dur a terme mitjançant la realització d'una tasca de distracció en la que els subjectes havien de discriminar estímuls visuals i ignorar sons distractors novedosos irrellevants. Els resultats mostraren l'existència d'un dèficit de processament auditiu primari en els subjectes dislèctics manifestat per un augment de l'amplitud i una demora dels components N1/MMN davant de tots els estímuls auditius, i alteracions en els processos atencionals dels dislèctics, mostrat per un pitjor rendiment i un augment del temps de reacció en la tasca conductual, i d'una disminució de l'amplitud i una demora del potencial P3a davant dels estímuls novedosos, especialment davant els estímuls novedosos familiars pel subjecte. Amb tot, aquest estudi demostrà alteracions atencionals auditives en els subjectes amb dislèxia del desenvolupament
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A ±25A Versatile Shunt-Based Current Sensor with 10kHz Bandwidth and ±0.25% Gain Error from -40°C to 85°C Using 2-Current Calibration
No full textAccurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is limited to a few tens of Hz, making them unsuitable for battery impedance or motor-current sensing. This paper presents a current sensor with a wide (10kHz) bandwidth and a tunable temperature compensation scheme (TCS), which allows it to be flexibly used with different types of shunts while maintaining high accuracy. A low-cost room-temperature calibration scheme is proposed to optimize gain flatness over temperature by exploiting the shunt's self-heating at large currents. Over the industrial temperature range and a ±25A current range, it achieves state-of-the-art gain error (±0.25%) with both low-cost PCB and stable metal-alloy shunts.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
An Article About Albertus C. Van Raalte, Author Unknown, Except for Parts Taken from an Article by Anna C. Post
No full textAn article about Albertus C. Van Raalte, author unknown, except for parts taken from an article by Anna C. Post. The author knew first generation persons in the Holland settlement and therefore, the article has some value.https://digitalcommons.hope.edu/vrp_1890s/1012/thumbnail.jp
Gating of Auditory Novelty Processing by Emotional Context / Augment de processament de novetat pel context emocional
No full text[eng] The present thesis encloses four studies that sought to asses the neural correlates, timing and modulatory effects of a negative emotional context on the processing of task-irrelevant novel sounds within the framework of auditory-visual oddball experimentation. Study I, II and III were conducted using event-related brain potentials (ERP) and Study IV used functional magnetic resonance imaging (fMRI). In Study I, fourteen healthy volunteers responded to a visual discrimination task, with either neutral or threatening sceneries, while a 64-channel electroencephalogram (EEG) was recorded. In Study II, fourteen healthy female volunteers responded to visual stimuli displaying either threatening or neutral sceneries, using an optimised version of the task, while a 64-channel electroencephalogram (EEG) was recorded. In Study III, fourteen female subjects and fourteen male subjects were recorded using a 64-channel electroencephalogram (EEG) while performing the same visual discrimination task as in Study II. In Study IV, seventeen healthy female volunteers responded to a visual colour discrimination task, with images of emotional facial expressions (angry, fearful or neutral), while neuroimaged in a 3Tesla scanner. In all experimental designs, single auditory stimuli, consisting of a majority of standard tones and infrequent novel environmental sounds, preceded the images and had to be ignored by the subjects. The main results in all four studies were pointing at comparable conclusions. Novel sounds elicited a distracting effect on subjects' performance, reflected by longer response times compared to those in standard trials. This effect was consistently magnified when preceding and following images were of a negative emotional load as compared to the neutral images. In Study III, women, but not men, showed this effect. Brain responses recorded with ERPs revealed, in Study I, an enhancement of late novelty-P3 responses to novel sounds in negative context, compared to the neutral one. Furthermore, Study II demonstrated that this modulatory effect can also occur in the early phase of this ERP component. Study III showed that the modulation of the early novelty-P3 was present only in women. Hemodynamic responses, in turn, showed that activation induced by novel sounds in superior temporal gyrus, comprising secondary cortex, planum temporale and primary auditory cortex, was enhanced when subjects responded to faces with a negative emotional expression compared to the neutral ones. The combination of results in the four studies show that the emotional context enhances excitability of auditory novelty cerebral regions at early stages of processing, making irrelevant sounds become more available in the attentional set under threatening conditions. Still, gender differences may be present in these effects, possibly due to differences in the evaluation of the emotional stimuli.[cat] La present tesi inclou quatre estudis que pretenen determinar els correlats neurals, temporalitat i efectes modulatoris d'un context emocional negatiu en el processament de sons novedosos irrellevants per la tasca en curs, en el marc de l'experimentació oddball auditivo- visual. L'Estudi I, II i III van ser duts a terme amb la tècnica de potencials evocats (PEs) i per l'Estudi IV es va utilitzar resonància magnètica funcional (RMf). A l'Estudi I, catorze voluntaris sans van respondre a una tasca de discriminació visual, amb escenes bé neutres, bé amenaçants, mentre s'enregistrava el seu electroencefalograma (EEG) de 64 canals. A l'Estudi II, catorze voluntàries sanes van respondre a estímuls visuals que representaven, bé escenes amenaçants o bé neutres, utilitzant una versió optimitzada de la tasca, mentre s'enregistrava el seu electroencefalograma (EEG) de 64 canals. A l'Estudi III, catorze dones i catorze homes van ser enregistrats utilitzant electroencefalograma (EEG) de 64 canals mentre realitzaven la mateixa tasca de discriminació visual que a l'Estudi II. A l'Estudi IV, disset voluntàries sanes van respondre a una tasca de discriminació de color, amb imatges d'expressions facials emocionals (d'amenaça, de por o neutra), mentre eren mesurades en un escàner de RMf de 3Tesla. En tots els dissenys experimentals, un estímul auditiu únic, que podia ser, bé en una majoria un to estàndard, o bé un so novedós ambiental infreqüent, precedia les imatges i havia d'ésser ignorat pels subjectes. Els principals resultats en tots quatre estudis apuntaren a conclusions comparables. Els sons novedosos produïren un efecte distractor en el rendiment dels subjectes, reflexat en temps de resposta més llargs comparats amb els assaigs amb sons estàndard. Aquest efecte va veure's consistentment magnificat quan les imatges precedents i següents tenien una càrrega emocional negativa en comparació a les imatges neutres. A l'Estudi III, les dones, però no els homes, van mostrar aquest efecte. Les respostes cerebrals enregistrades amb PEs revelaren, a l'Estudi I, un augment d'amplitud de la fase tardana del patró P3 de novetat davant de sons novedosos en context negatiu, en comparació amb el context neutre. A més, l'Estudi II va demostrar que aquest efecte modulatori pot ocórrer també en la fase primerenca d'aquest component de PE. L'Estudi III va mostrar que la modulació de la P3 de novetat era present només en dones. Les respostes hemodinàmiques, alhora, van mostrar que l'activació induïda pels sons novedosos al gir temporal superior, incloent escorça auditiva secundària, planum temporale i escorça auditiva primària, va ser augmentada quan els subjectes respongueren a cares amb una expressió emocional negativa en comparació amb les neutres. La combinació de resultats en els quatre estudis mostra que el context emocional augmenta l'excitabilitat de regions cerebrals en àrees primerenques de processament, fent que sons irrellevants es esdevinguin més disponibles en el set atencional en condicions d'amenaça. Tanmateix, és possible l'existència de diferències de gènere en aquests efectes, possiblement degut a diferències en l'avaluació dels estímuls emocionals. REFERENCES Alho, K., Winkler, I., Escera, C., Huotilainen, M., Virtanen, J., Jääskelainen, I.P., Pekkonen, E., Ilmoniemi, R.J. (1998). Processing of novel sounds and frequency changes in the human auditory cortex: magnetoencephalographic recordings. Psychophysiology, 35, 211-224. Bledowski, C., Prvulovic, D., Hoechstetter, K., Scherg, M., Wibral, M., Goebel, R., Linden, D.E.J. (2004). Localizing P300 generators in visual target and distractor processing: a combined event-related potential and functional magnetic resonance imaging study. The Journal of Neuroscience, 24(42), 9353-9360. Bradley, M.M., Codispoti, M., Lang, P.J. (2006). A multi-process account of startle modulation during affective perception. Psychophysiology, 43, 486-497. Clark, V.P., Fannon, S., Lai, S., Benson, R., Bauer, L. (2000). Responses to rare visual target and distractor stimuli using event-related fMRI. Journal of Neurophysiology, 83, 3133-3139. Cuthbert, B.N., Schupp, H.T., Bradley, M.M., McManis, M., Lang, P.J. (1998). Probing affective pictures: attended startle and tone probes. Psychophysiology, 35, 344-347. Escera, C., Alho, K., Winkler, I., Näätäänen, R. (1998). Neural mechanisms of involuntary attention to acoustic novelty and change. Journal of Cognitive Neuroscience, 10(5), 590-604. Escera, C., Alho, K., Schröger, E., Winkler, I. (2000). Involuntary attention and distractibility as evaluated with event-related brain potentials. Audiology and Neurootology, 5, 151-166
Archivist, Archaeologist, Author and the Tactile Window
No full textThe idea that the predominant way of engaging with architecture is through vision is not uncommon but also not always the most appropriate given that buildings are also experienced through tactile interventions. This consequence that emphasises visual aesthetics in order to appreciate and understand architecture probably has much to do with the assumed but rather vaguely defined role of the architect as designer in the practice of architectural design. A resulting misapprehension is that architects designing for visual appreciation think that they are actually designing physical space for embodied tactile engagement.
This prioritisation of vision in the way architects think about and approach design is questioned through the design project of the Tactile Window in which the position of the architect is redefined through inhabiting the roles of archivist, archaeologist and author during the design process.
A 16th century portrait of Queen Elizabeth I known as the Ditchley portrait, currently on display at the National Portrait Gallery is used as the source from which the design of the Tactile Window is derived from and refers back to. Questioning the validity of vision as the sole means of engaging with the work, information about the portrait and working methods gathered from the three carefully chosen positions mentioned above are drawn on and applied to the making of this Tactile Window that becomes an alternative Ditchley portrait. Through exploring the hidden historical and current narratives of and in the existing portrait, the presence of the portrait is alluded to on an alternative physical site. Key to this are the working methods of an invented archival system of design reasoning, the unearthing of archaeological texts and assuming of authorship within the individual frameworks of the roles of archivist, archaeologist and author.
The redefined role of the architect as archaeologist takes onboard the unearthing of associated drawings and writings as well as the methods of organising and applying the recovered information to the system set up by the archivist. This analysis of the graphic and text based information is used to formulate historical narratives that are woven into the design project. Whereas traditional archaeology stresses on the study of a site from a site with quantifiable limits to the physical context, the notion of archaeological sites in this instance refers to the places where the stored information is unearthed. Through the careful process of archiving and analysing this information, a new site that is located within both the physical and historical contexts of interest is discovered. The author then draws upon the elements in the archival system that includes the findings of the archaeologist to construct the alternative Ditchley portrait in this new site of the Echoing Cedar, the result of which bears no visual resemblance to the existing work.
The Tactile Window is a reading of the Ditchley portrait in which information about and in the painting is transformed into a design proposal for an inhabited structure. The intended method of interaction with this alternative portrait is not merely restricted to vision but relies on engagement with the other senses. This experience is enhanced by the interplay with certain site conditions such as wind and rain in order to allude to specific aspects of the Ditchley portrait that are not visually apparent in the existing work.
In the processes of excavating, finding and revealing the hidden information to create this alternative portrait, the effects of the visuals afforded by the existing portrait inadvertently begin to fade as the validity of a single means of visual expression is questioned
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