620 research outputs found
Foveal avascular zone and choroidal thickness are decreased in subjects with hard drusen and without high genetic risk of developing Alzheimer’s disease
A family history (FH+) of Alzheimer’s disease (AD) and ɛ4 allele of the ApoE gene are the main genetic risk factors for developing AD, whereas ɛ4 allele plays a protective role in age-related macular degeneration. Ocular vascular changes have been reported in both pathologies. We analyzed the choroidal thickness using optical coherence tomography (OCT) and the foveal avascular zone (FAZ) using OCT-angiography and compared the results with ApoE gene expression, AD FH+, and the presence or absence of hard drusen (HD) in 184 cognitively healthy subjects. Choroidal thickness was statistically significantly different in the (FH−, ɛ4−, HD+) group compared with (i) both the (FH−, ɛ4−, HD−) and the (FH+, ɛ4+, HD+) groups in the superior and inferior points at 1500 μm, and (ii) the (FH+, ɛ4−, HD+) group in the superior point at 1500 μm. There were statistically significant differences in the superficial FAZ between the (FH+, ɛ4−, HD+) group and (i) the (FH+, ɛ4−, HD−) group and (ii) the (FH+, ɛ4+, HD−) group. In conclusion, ocular vascular changes are not yet evident in participants with a genetic risk of developing AD
Characterization of retinal drusen in subjects at high genetic risk of developing sporadic Alzheimer’s disease: An exploratory analysis
Having a family history (FH+) of Alzheimer’s disease (AD) and being a carrier of at least one ε4 allele of the ApoE gene are two of the main risk factors for the development of AD. AD and age-related macular degeneration (AMD) share one of the main risk factors, such as age, and characteristics including the presence of deposits (Aβ plaques in AD and drusen in AMD); however, the role of apolipoprotein E isoforms in both pathologies is controversial. We analyzed and characterized retinal drusen by optical coherence tomography (OCT) in subjects, classifying them by their AD FH (FH-or FH+) and their allelic characterization of ApoE ε4 (ApoE ε4-or ApoE ε4+) and considering cardiovascular risk factors (hypercholesterolemia, hypertension, and diabetes mellitus). In addition, we analyzed the choroidal thickness by OCT and the area of the foveal avascular zone with OCTA. We did not find a relationship between a family history of AD or any of the ApoE isoforms and the presence or absence of drusen. Subjects with drusen show choroidal thinning compared to patients without drusen, and thinning could trigger changes in choroidal perfusion that may give rise to the deposits that generate drusen
The Impact of the Eye in Dementia: The Eye and its Role in Diagnosis and Follow‐up
Over the last few decades, the importance of ophthalmic examination in neurodegenerative diseases of the CNS has reportedly increased. The retina is an extension of the CNS and thus should not be surprising to find abnormal results in both the test exploring visual processing and those examining the retina of patients with CNS degeneration. Current in vivo imaging techniques are allowing ophthalmologists to detect and quantify data consistent with the histopathological findings described in the retinas of Alzheimer’s disease (AD) patients and may help to reveal unsuspected retinal and optic‐nerve repercussions of other CNS diseases. In this chapter, we perform an analysis of the physiological changes in ocular and cerebral ageing. We analyse the ocular manifestations in CNS disorders such as stroke, AD and Parkinson’s disease. In addition, the pathophysiology of both the eye and the visual pathway in AD are described. The value of the visual psychophysical tests in AD diagnosis is reviewed as well as the main findings of the optical coherence tomography as a contribution to the diagnosis and monitoring of the disease. Finally, we examine the association of two neurodegenerative diseases, AD and glaucoma, as mere coincidence or possible role in the progression of the neurodegeneration
Selectividad animal en rastrojos de paisajes ganaderos de la Amazonia Colombiana
Esta investigación surge de la necesidad de información para reconocer los bienes y seruicios ofertados por unidades de los paisajes ganaderos en la Amazonia colombiana conformados por procesos de vegetación secundaria originados a partir de regeneración natural, localmente llamados rastrojos. A partir de pruebas de cafetería con bovinos, se identificaron especies de plantas con diferentes niveles de selectividad. Se generó un indicador de selectividad (lS) para cada especie consumida en los tres sitios de estudio, ubicados en los municipios de El Doncello, Florencia y Belén de los Andaquíes. El lS se calculó en función del consumo (número de bocados) y la abundancia de la especie consumida. Para la interpretación de los resultados se consideró que un valor de lS mayor de 1,3 indica que la especie estuvo siendo preferida sobre otras; siestaba en un rango entre 0,7 y 1,3 se consideró la especie como neutra y si el IS era menor de 0,7 se consideraba la especie como rechazada, es decir, esta especie no fue bien consumida por los animales. Las especies seleccionadas o preferidas se dividieron en dos categorías: las altamente preferidas cuando el lS fue mayor a2,5y las medianamente preferidas o de mantenimiento cuando el lS estuvo en un rango entre 2,49 y 1,31. En los tres sitios estudiados se encontraron 43 especies con diferentes niveles de consumo, de las cuales 22 plantas fueron catalogadas como altamente preferidas, 5 especies como medianamente preferidas, 5 especies neutras y 11 especies rechazadas. Las plantas con alto lS pertenecen a las familias Rutaceae, Lamiaceae, Euphorbiaceae y Asteraceae. De 34 especies reconocidas por los productores 9 son arbóreas, 9 arbustos y 16 son catalogadas como herbáceas. Los rastrojos estudiados presentaron una importante oferta de plantas con potencial forrajero y con posibilidad de inclusión en sistemas silvopastoriles desarrollados a partir de procesos de regeneración natural o rastrojos
Changes in retinal OCT and their correlations with neurological disability in early ALS patients, a follow-up study
Background: To compare early visual changes in amyotrophic lateral sclerosis (ALS) patients with healthy controls in a baseline exploration, to follow-up the patients after 6 months, and to correlate these visual changes with neurological disability. Methods: All patients underwent a comprehensive neurological and ophthalmological examination. A linear mixed analysis and Bonferroni p-value correction were performed, testing four comparisons as follows: Control baseline vs. control follow-up, control baseline vs. ALS baseline, control follow-up vs. ALS follow-up, and ALS baseline vs. ALS follow-up. Results: The mean time from the diagnosis was 10.80 +/- 5.5 months. The analysis of the optical coherence tomography (OCT) showed: (1) In ALS baseline vs. control baseline, a macular significantly increased thickness of the inner macular ring temporal and inferior areas; (2) in ALS follow-up vs. ALS baseline, a significant macular thinning in the inner and outer macular ring inferior areas; (3) in ALS follow-up vs. ALS baseline, a significant peripapillary retinal nerve fiber layer (pRNFL) thinning in the superior and inferior quadrants; and (4) ALS patients showed a moderate correlation between some OCT pRNFL parameters and Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) score. Conclusion: The OCT showed retinal changes in patients with motoneuron disease and could serve as a complementary tool for studying ALS
Anatomy of the Human Optic Nerve: Structure and Function
The optic nerve (ON) is constituted by the axons of the retinal ganglion cells (RGCs). These axons are distributed in an organized pattern from the soma of the RGC to the lateral geniculated nucleus (where most of the neurons synapse). The key points of the ON are the optic nerve head and chiasm. This chapter will include a detailed and updated review of the ON different parts: RGC axons, glial cells, connective tissue of the lamina cribrosa and the septum and the blood vessels derivate from the central retina artery and from the ciliary system. There will be an up-to-date description about the superficial nerve fibre layer, including their organization, and about prelaminar, laminar and retrolaminar regions, emphasizing the axoplasmic flow, glial barriers, biomechanics of the lamina cribrosa and the role of the macro- and microglia in their working
Identification keys for the fish of continental and insular waters of Costa Rica. Part I: Families
Introducción: El conocimiento sobre la composición taxonómica de la fauna de peces de agua dulce de Costa Rica ha cambiado sustancialmente en las últimas dos décadas. No solamente por la adición de nuevas especies y táxones supra-específicos, sino también por reordenamientos y cambios taxonómicos en los diferentes niveles jerárquicos. Las claves taxonómicas disponibles se publicaron hace más de 20 años y están desactualizadas. Objetivo: Brindar información actualizada, en lenguaje sencillo, para la identificación de todas las familias costarricenses de peces continentales e insulares. Métodos: Utilizamos literatura especializada, colecciones de museos y especímenes recolectados recientemente para actualizar las claves disponibles tomando como referencia una lista de familias del 2013. Resultados: La clave dicotómica ilustrada, que cubre 53 familias, se basa en características externas relativamente fáciles de identificar. También incluimos información sobre la composición de especies, distribución general y uso del hábitat. Conclusión: Esta clave permite la identificación de 274 especies de peces costarricenses a nivel de familia, como base para su identificación a categorías más bajasIntroduction: Knowledge about the taxonomic
composition of the Costa Rican freshwater fish fauna has
changed substantially in the last two decades. Not only
due to the addition of new species and supra-specific
taxa, but also due to rearrangements and taxonomic
changes at the different hierarchical levels. The available
taxonomic keys were published more than 20 years ago
and are outdated. Objective: To provide up-to-date
information, in a friendly language, for the identification
of all Costa Rican families of continental and insular
fishes. Methods: We used the literature, museum
collections and recently collected specimens to update a
2013 family list. Results: The key covers 53 families. The
illustrated dichotomous key is based on external
characters that are relatively “easy” to identify. We also
include information about species composition, general
distribution and habitat use. Conclusion: This key allows
the identification of 274 fish species to family level, as a
basis for further identification.Universidad de Costa Rica/[808-C1-125]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biodiversidad y Ecología Tropical (CIBET)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR
Soluciones Creativas de Intervención (LUGH)
En este texto se puede encontrar información sobre los antecedentes del proyecto LUGH ITESO Soluciones creativas de intervención, así como los objetivos del trabajo que incluyen la vinculación entre empresas socialmente responsables con escenarios, comunidades, organizaciones u otros esfuerzos de la sociedad por mejorar su entorno. De este modo la empresa obtiene un beneficio en términos de posicionamiento, a la vez que produce un beneficio social tangible. Durante el período primavera 2016, se desarrollaron estrategias y piezas de comunicación para las organizaciones Plenitud de vida, Concertando México, Juntos por los demás y Capeltic. En este informe se incluye también la descripción del método de trabajo que el proyecto propone para la realización de estrategias de comunicación e intervención social
Assessment of the Skill of Coupled Physical-Biogeochemical Models in the NW Mediterranean
18 pages, 13 figures, supplementary material https://www.frontiersin.org/articles/10.3389/fmars.2020.00497/full#supplementary-material.-- Publicly available datasets were analyzed in this study. This data can be found here: http://marine.copernicus.eu/services-portfolio/access-to-products/, http://www.ba.ieo.es/ibamar, http://thredds.socib.es/thredds/catalog.htmlNumerical modeling is a key tool to complement the current physical and biogeochemical observational datasets. It is essential for understanding the role of oceanographic processes on marine food webs and producing climate change projections of variables affecting key ecosystem functions. In this work, we evaluate the horizontal and vertical patterns of four state-of-the-art coupled physical–biogeochemical models, three of them already published. Two of the models include data assimilation, physical and/or biological, and two do not. Simulations are compared to the most exhaustive dataset of in situ observations in the North Western Mediterranean, built ad hoc for this work, comprising gliders and conventional CTD surveys and complemented with satellite observations. The analyses are performed both in the whole domain and in four subregions (Catalan Shelf, Ebro Delta, Mallorca Channel, and Ibiza Channel), characterized by a priori divergent primary production dynamics and driving mechanisms. Overall, existing models offer a reasonable representation of physical processes including stratification, surface temperature, and surface currents, but it is shown that relatively small differences among them can lead to large differences in the response of biogeochemical variables. Our results show that all models are able to reproduce the main seasonal patterns of primary production both at the upper layer and at the deep chlorophyll maximum (DCM), as well as the differential behavior of the four subregions. However, there are significant discrepancies in the local variability of the intensity of the winter mixing, phytoplankton blooms, or the intensity and depth of the DCM. All model runs show markedly contrasting patterns of interannual phytoplankton biomass in all four subregions. This lack of robustness should dissuade end users from using them to fill gaps in time series observations without assessing their appropriateness. Finally, we discuss the usability of these models for different applications in marine ecology, including fishery oceanographyThis work was supported by the European Union’s Horizon 2020 Research and Innovation Program under grant agreement no. 678193 (CERES, Climate Change and European Aquatic Resources). ER-R is grateful for the funding from “Govern de les Illes Balears-Conselleria d’Innovació, Recerca i Turisme, Programa Vicenç Mut.”With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)Peer reviewe
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