770 research outputs found
Formación y actualización de maestros: Una experiencia referida a la conceptualización de los fenómenos de la visión del color
In this work we present the results of a research done during a workshop with teachers of level EGBl.We investigated the conceptual constructions of vision and the perception of colour.</p
Egocentric and allocentric spatial reference frames in aging: A systematic review
Abstract Aging affects many aspects of everyday living, such as autonomy, security and quality of life. Among all, spatial memory and spatial navigation show a gradual but noticeable decline, as a result of both neurobiological changes and the general slowing down of cognitive functioning. We conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to identify studies that specifically investigated the role of allocentric and egocentric frames in healthy aging. Concerning spatial navigation, our results showed a preservation of egocentric strategies, along with specific impairments in the use of allocentric and switching abilities. Regarding spatial memory, instead, outcomes were more divergent and not frame-specific. With this perspective, spatial impairments were discussed considering the cognitive profile of mild cognitive impairment (MCI) and Alzheimer's Disease (AD)
Experiencia en el campo de la iluminación, la luz y la visión: crecimiento institucional a partir del trabajo en red y de la vinculación tecnológica
El Departamento de Luminotecnia, Luz y Visión (DLLyV) de la Facultad de Ciencias
Exactas y Tecnología de la Universidad Nacional de Tucumán y el Instituto de
Investigación en Luz, Ambiente y Visión de doble pertenencia (CONICET-UNT), han
logrado imponerse como una institución de punta en toda Latinoamérica en sus áreas de
injerencia. Ello se debió a un incipiente trabajo en red con instituciones complementarias
(Ecuador, Colombia, España, Brasil), y a una entusiasta vinculación con el sector
productivo (empresas), y gubernamentales (municipios, gobiernos provinciales). Fue el
Estado a través de instituciones de Ciencia y Tecnología uno de los propulsores
fundamentales de tales iniciativas, mediante múltiples líneas de financiamiento (ANPCyT,
MINCyT, CONICET, SPU, Secretaría de Ciencia y Técnica de la Universidad Nacional de
Tucumán, etc). Todo ello, deviniendo en aplicaciones concretas en la sociedad, actuales y
potenciales
Brightness reduction as a function of the angular position of a glare source
El efecto de difusión intraocular de luz generada por una fuente deslumbrante periférica se cuantifica mediante un modelo formulado empíricamente en términos de la luminancia de velo. Esta luminancia es directamente proporcional a la iluminancia generada en el ojo por dicha fuente e inversamente proporcional al cuadrado del ángulo de excentricidad subtendido por la fuente con el eje visual. En artículos previos se analiza el efecto de reducción de claridad en presencia de una fuente deslumbrante a 10º y se obtiene que el efecto aumenta al crecer la iluminancia generada por la fuente. En el presente trabajo se investiga la dependencia de la reducción de claridad con el ángulo de excentricidad de una fuente deslumbrante transitoria que genera 60lux en el ojo. Se usa un método de comparación de magnitudes en el que la claridad percibida de un estimulo de luminancia variable presentado sin deslumbramiento se compara con la de uno de referencia presentado en sincronía con el deslumbramiento. Para 5 adultos jóvenes emétropes resulta que, al disminuir el ángulo de 15º a 7.5º, la luminancia de igualación se reduce como lo predice el modelo de luminancia de velo. Esto indicaría que el fenómeno de reducción de claridad es fuertemente dependiente del velo producido por la fuente deslumbrante. Los resultados obtenidos se comparan con los de otros autores hallados bajo condiciones de deslumbramiento estable.The effect of intraocular scattering of light generated at a peripheral glare source is quantified using a model empirically formulated in terms of the veiling luminance. This luminance is directly proportional to the illuminance generated at the eye by this source and inversely proportional to the square of the eccentricity angle subtended by the source with the visual axis. In previous articles the effect of brightness reduction due to the presence of a glare source subtending 10º is analyzed and it results that this effect increases when the illuminance generated by the source increases. In the present paper the dependence of brightness reduction on the eccentricity angle of a transient glare source generating 60lux at the eye is investigated. A method of magnitudes comparison, consisting in comparing the perceived brightness of a stimulus of variable luminance presented without glare to that of a reference stimulus presented simultaneously with glare, is employed. For 5 emmetropic young adults it results that, when the angle decreases from 15º to 7.5º, the matching luminance decreases as predicted by the veiling luminance model. This would indicate that the brightness reduction phenomenon is strongly dependent on the veil produced by the glare source. The results obtained are compared to those of other authors found under stable glare conditions.Fil: Issolio, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; ArgentinaFil: Juliana Matranga. No especifica;Fil: Pablo Barrionuevo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; ArgentinaFil: Comastri, Silvia Ana Elva. No especifica;Fil: Gabriel Martin. No especifica;Fil: Colombo, Elisa Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; Argentin
Metodología para evaluar efectos del deslumbramiento en amétropes corregidos
Light originated at a glare source and entering the eye, produces a veiling luminance that causes contrast decrease in retinal images and this effect could differ if the subject wears lenses or not. In this work the glare effects in subjects wearing lenses is studied inducing ammetropies in emmetropes. Contrast thresholds of sinusoidal patterns of 2 cpd and 0.5 cd/m2 are evaluated without and with glare, the glare source being steady, at 12o and producing 60 lx at the cornea. To exemplify the use of this methodology, 2 emmetropes under 8 different conditions are considered: naked eye; 3 control conditions (wearing neutral lenses) and 4 ammetropic conditions, inducing low (2 D) and medium (5 D) myopia and hyperopia with positive and negative contact lenses and correcting them with adequate ophthalmic lenses. The contrast threshold differences between the naked eye and the other 7 conditions are statistically not significant without glare and significant (up to more than 100%) with glare, independently of lens power and probably due to ectopic scattering and multiple reflections. The method proposed enables the determination of the glare effects if lenses are worn though a greater population is required to attain conclusive data.La luz originada en una fuente deslumbrante que entra al ojo, produce una luminancia de velo que causa una disminución de contraste en las imágenes retinianas y este efecto podría diferir si el sujeto usa lentes o no. En este trabajo se estudian los efectos del deslumbramiento en sujetos que usan lentes induciendo ametropías en emétropes. Se evalúan contrastes umbrales de patrones sinusoidales de 2 cpd y 0.5 cd/m2 sin y con deslumbramiento, la fuente deslumbrante siendo estable, a 12º y produciendo 60 lx en la córnea. Para ejemplificar el uso de esta metodología, se consideran 2 emétropes en 8 condiciones diferentes: ojo desnudo; 3 condiciones de control (lentes neutras) y 4 condiciones ametrópicas, induciendo miopía e hipermetropía baja (±2 D) y media (±5 D) con lentes de contacto positivas y negativas y corrigiéndolas con adecuadas lentes oftálmicas. Las diferencias de contraste entre el ojo desnudo y las otras 7 condiciones son estadísticamente no significativas sin deslumbramiento y significativas (hasta más de 100%) con deslumbramiento, independientemente de la potencia de la lente y probablemente debido a scattering ectópico y reflexiones múltiples. El método propuesto permite determinar los efectos de deslumbramiento al usar lentes aunque, para tener datos contundentes, se requiere una mayor poblaciónFil: de Paul Camacho, Anibal Gabriel. Universidad Nacional de Tucuman. Facultad de Cs.exactas y Tecnologia. Departamento de Luminotecnia, Luz y Vision; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucuman. Instituto de Investigacion En Luz, Ambiente y Vision; ArgentinaFil: Colombo, Elisa Margarita. Universidad Nacional de Tucuman. Facultad de Cs.exactas y Tecnologia. Departamento de Luminotecnia, Luz y Vision; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucuman. Instituto de Investigacion En Luz, Ambiente y Vision; ArgentinaFil: Comastri, Silvia Ana Elva. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ingenieria. Departamento de Fisica; ArgentinaFil: Aparicio, Juan A.. Universidad de Valladolid. Facultad de Ciencias; EspañaFil: Menéndez, José Antonio. Universidad de Valladolid. Facultad de Ciencias; EspañaFil: Issolio, Luis Alberto. Universidad Nacional de Tucuman. Facultad de Cs.exactas y Tecnologia. Departamento de Luminotecnia, Luz y Vision; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucuman. Instituto de Investigacion En Luz, Ambiente y Vision; Argentin
Gulliver’s virtual travels: active embodiment in extreme body sizes for modulating our body representations
It is noted that the perceptual experience of body and space can be modulated by changing the action capabilities or by manipulating the perceived body dimensions through a multisensory stimulation. This study adds to pre-existing literature by investigating the alterations in bodily experience following embodiment to both enlarged and shrunked bodies, while participants actively navigated in a virtual environment. A normal-sized body served as a reference condition. After each embodied navigation, participants estimated the height and width of three different body parts. Results revealed that the embodiment over shrunked body induced a significant reduction in participants’ body image, while no changes were reported after the embodiment over the enlarged body. Findings were discussed in terms of previous literature exploring the constraints implicated in the ownership over different bodies
Assessment of Unilateral Spatial Neglect Using a Free Mobile Application for Italian Clinicians
Background: Unilateral Spatial Neglect (USN) is traditionally assessed with paper-and-pencil tests or computer-based tests. Thanks to the wide-spreading of mobile devices, and the extensive capabilities that they have in dealing complex elements, it is possible to provide clinicians with tools for cognitive assessment. Contemporary 3D engine is, in general generally, able to deploy complex 3D environments for iOS, Android and Windows mobile, i.e., most of the mobile phone and tablet operative systems.Results: This brand-new scenario and pressing requests from professionals, pushed us to build an application for the assessment of USN. Our first attempt was to replicate the classic cognitive tests, traditionally used at this purpose. Ecological assessment is difficult in real scenarios so we implemented virtual environments to assess patients’ abilities in realistic situations. At the moment, the application is available only for iPad and iPhone for free, from the Apple Store, under the name of “Neglect App.” The App contains traditional tests (e.g., barrage with and without distractors) and ecological tests (e.g., to distribute the tea in a table to close people). Scoring of each test is available to the clinicians through a database with the executed ecological tasks, that are stored locally.Conclusion: In conclusion, Neglect App is an advanced mobile platform for the assessment of Neglect
“Positive Bike” – An immersive biking experience for combined physical and cognitive training of elderly patients
Previous evidence shows that combined cognitive and physical exercises (dual-task intervention, (I-DT)) potentiates cognitive performance more than either type of single training alone (Lauenroth et al., 2015). Here, we describe the rationale, the design and the implementation of the “Positive Bike”, a fully-immersive virtual reality biking experience for implementing I-DT training protocols in older patients. The system consists of a cycle-ergometer positioned within a Cave Automatic Virtual Environment (CAVE). The system also features a cloud-based platform which allows the therapist to configure the exercise parameters (i.e, duration and load). Using the Positive Bike, the patient can take a virtual ride by physically pedalling at variable paces within a simulated scenario (i.e., a park). During the virtual ride, the patient can be presented with different interactive cognitive exercises (attentional, memory etc). In one of such exercises, for example, the patient has to recognize different animals appearing on the route sides and press a button if such animal has a name beginning with a specific letter. Potential applications of Positive Bike in geriatric wellness and rehabilitation are discussed
Emergent Ascomycetes in viticulture: an interdisciplinary overview
The reduction of pesticide usage is a current imperative and the implementation of sustainable viticulture is an urgent necessity. A potential solution, which is being increasingly adopted, is offered by the use of grapevine cultivars resistant to its main pathogenic threats. This, however, has contributed to changes in defense strategies resulting in the occurrence of secondary diseases, which were previously controlled. Concomitantly, the ongoing climate crisis is contributing to destabilizing the increasingly dynamic viticultural context. In this review, we explore the available knowledge on three Ascomycetes which are considered emergent and causal agents of powdery mildew, black rot and anthracnose. We also aim to provide a survey on methods for phenotyping disease symptoms in fields, greenhouse and lab conditions, and for disease control underlying the insurgence of pathogen resistance to fungicide. Thus, we discuss fungal genetic variability, highlighting the usage and development of molecular markers and barcoding, coupled with genome sequencing. Moreover, we extensively report on the current knowledge available on grapevine-ascomycete interactions, as well as the mechanisms developed by the host to counteract the attack. Indeed, to better understand these resistance mechanisms, it is relevant to identify pathogen effectors which are involved in the infection process and how grapevine resistance genes function and impact the downstream cascade. Dealing with such a wealth of information on both pathogens and the host, the horizon is now represented by multidisciplinary approaches, combining traditional and innovative methods of cultivation. This will support the translation from theory to practice, in an attempt to understand biology very deeply and manage the spread of these Ascomycetes
Myocardial infarction with non-obstructive coronary arteries (MINOCA. focus on coronary microvascular dysfunction and genetic susceptibility
Among the most common causes of death worldwide, ischemic heart disease (IHD) is recognized to rank first. Even if atherosclerotic disease of the epicardial arteries is known as the leading cause of IHD, the presence of myocardial infarction with non-obstructive coronary artery disease (MINOCA) is increasingly recognized. Notwithstanding the increasing interest, MINOCA remains a puzzling clinical entity that can be classified by distinguishing different underlying mechanisms, which can be divided into atherosclerotic and non-atherosclerotic. In particular, coronary microvascular dysfunction (CMD), classifiable in non-atherosclerotic mechanisms, is a leading factor for the pathophysiology and prognosis of patients with MINOCA. Genetic susceptibility may have a role in primum movens in CMD. However, few results have been obtained for understanding the genetic mechanisms underlying CMD. Future studies are essential in order to find a deeper understanding of the role of multiple genetic variants in the genesis of microcirculation dysfunction. Progress in research would allow early identification of high-risk patients and the development of pharmacological, patient-tailored strategies. The aim of this review is to revise the pathophysiology and underlying mechanisms of MINOCA, focusing on CMD and actual knowledge about genetic predisposition to it
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