scholarly journals Gradual Increase in Environmental Light Intensity Induces Oxidative Stress and Inflammation and Accelerates Retinal Neurodegeneration

2020 ◽  
Vol 61 (10) ◽  
pp. 1
Author(s):  
Oksana Kutsyr ◽  
Xavier Sánchez-Sáez ◽  
Natalia Martínez-Gil ◽  
Emilio de Juan ◽  
Pedro Lax ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Light Intensity ◽  
Gradual Increase ◽  
Environmental Light ◽  
Retinal Neurodegeneration

Fine structure of the retina of the giant scallop, Placopecten magellanicus

1984 ◽  
Vol 42 ◽  
pp. 312-313
Author(s):  
C.V.L. Powell
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Light Intensity ◽  
Scanning Electron Microscope ◽  
Eye Development ◽  
Preliminary Observation ◽  
Columnar Epithelium ◽  
Placopecten Magellanicus ◽  
Environmental Light ◽  
Scanning Electron

The overall fine structure of the eye in Placopecten is similar to that of other scallops. The optic tentacle consists of an outer columnar epithelium which is modified into a pigmented iris and a cornea (Fig. 1). This capsule encloses the cellular lens, retina, reflecting argentea and the pigmented tapetum. The retina is divided into two parts (Fig. 2). The distal retina functions in the detection of movement and the proximal retina monitors environmental light intensity. The purpose of the present study is to describe the ultrastructure of the retina as a preliminary observation on eye development. This is also the first known presentation of scanning electron microscope studies of the eye of the scallop.

Changes in Levels of a-Tocopherol and Ascorbate in Spruce Needles at Three Low Mountain Sites Exposed to Mg2+-Deficiency and Ozone

1994 ◽  
Vol 49 (3-4) ◽  
pp. 171-180 ◽  
Author(s):  
U. Schmieden ◽  
A. Wild
Keyword(s):  
Oxidative Stress ◽  
Light Intensity ◽  
Chlorophyll A ◽  
Antioxidant Status ◽  
Photosynthetic Capacity ◽  
High Light Intensity ◽  
High Light ◽  
Absolute Level ◽  
Ozone Concentrations ◽  
Spruce Needles

The main objective of this study was the com parison of changes in levels of α-tocopherol and ascorbate in needles of spruce trees with various degrees of damage at three low mountain sites. The ascorbate content in needles of spruce trees with various degrees of dam age differs in the course of seasons as well as in the absolute level. The antioxidant status was affected mainly during summer. The content of ascorbate in needles of dam aged trees was significantly increased compared to that of undamaged trees. Despite seasonal and daily fluctuations, the level of ascorbate seems to be a good indicator for the degree of dam age in the case of symptoms described as montane yellowing. Together with an increasing content of α-tocopherol per chlorophyll, a rise of ascorbate content indicates enhanced oxidative stress in the needles of damaged trees, particularly in summer. Asc/αToc ratios were increased in needles of damaged trees. At the studied sites enhanced oxidative stress could be caused by the com bined action of Mg2+-deficiency, high ozone concentrations and high-light intensity, all inducing an increased production of radicals in combination with a reduced photosynthetic capacity

scholarly journals Eyes as Gateways for Environmental Light to the Substantia Nigra: Relevance in Parkinson’s Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Stefania Romeo ◽  
Daniela Di Camillo ◽  
Alessandra Splendiani ◽  
Marta Capannolo ◽  
Cristina Rocchi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Light Intensity ◽  
Substantia Nigra ◽  
Light Exposure ◽  
Bright Light ◽  
Human Head ◽  
Resonance Imaging ◽  
Environmental Light

Recent data indicates that prolonged bright light exposure of rats induces production of neuromelanin and reduction of tyrosine hydroxylase positive neurons in thesubstantia nigra. This effect was the result of direct light reaching thesubstantia nigraand not due to alteration of circadian rhythms. Here, we measured the spectrum of light reaching thesubstantia nigrain rats and analysed the pathway that light may take to reach this deep brain structure in humans. Wavelength range and light intensity, emitted from a fluorescent tube, were measured, using a stereotaxically implanted optical fibre in the rat mesencephalon. The hypothetical path of environmental light from the eye to thesubstantia nigrain humans was investigated by computed tomography and magnetic resonance imaging. Light with wavelengths greater than 600 nm reached the ratsubstantia nigra, with a peak at 709 nm. Eyes appear to be the gateway for light to the mesencephalon since covering the eyes with aluminum foil reduced light intensity by half. Using computed tomography and magnetic resonance imaging of a human head, we identified the eye and the superior orbital fissure as possible gateways for environmental light to reach the mesencephalon.

scholarly journals Production of Lutein-enriched Biomass by Growing Coccomyxa sp. (strain onubensis; Chlorophyta) under Spring Outdoor Conditions of Southwest Spain

2016 ◽  
Vol 6 (1) ◽  
pp. 828-834 ◽  
Author(s):  
Isabel Vaquero ◽  
M. Carmen Ruiz-Domínguez ◽  
Benito Mogedas ◽  
Carlos Vílchez ◽  
José M Vega
Keyword(s):  
Light Intensity ◽  
Large Scale ◽  
Biomass Productivity ◽  
Dry Weight ◽  
Acidic Environment ◽  
Intensity Maximum ◽  
Tubular Photobioreactor ◽  
Outdoor Culture ◽  
Environmental Light ◽  
Intracellular Content

Coccomyxa sp. (strain onubensis) is an acidic environment microalga, which was grown under spring outdoor conditions of Huelva province (southwest, Spain). A 6 L pilot tubular photobioreactor was used to determine the influence of the environmental light and temperature conditions on the microalga growth and its intracellular content of carotenoids. Cloudy days supplied the adequate light intensity (maximum 1070 μmol photons m-2 s-1) and temperature (maximum 32ºC) regimes for a biomass productivity of 0.28 g L-1 d-1 with an intracellular content of lutein (4.8 mg g-1 dry weight) and eventually β-carotene (0.8 mg g-1) obtained at the end of the day evening. This work supplies guidelines for a large-scale outdoor culture of Coccomyxa. sp. to supply lutein-enriched biomass, with the advantage of the growth at pH 2.5, which preserves cultures from contamination.  

Prototype of Student Attendance Application Based on Face Recognition Using Eigenface Algorithm

2019 ◽  
Vol 3 (1) ◽  
pp. 23
Author(s):  
Tio Eko Prabowo ◽  
Rudy Hartanto ◽  
Sunu Wibirama
Keyword(s):  
Face Recognition ◽  
Light Intensity ◽  
Recognition Accuracy ◽  
Recognition Algorithm ◽  
Test Results ◽  
Student Attendance ◽  
Environmental Light ◽  
Student Manual ◽  
Face Detection And Recognition ◽  
Axis Rotation

Prototype of face recognition based attendance application that has been developed to overcome weaknesses in DTETI UGM student manual attendance system has several weaknesses. These weaknesses are a decrease in facial recognition accuracy when operating under conditions of varying environmental light intensity and in condition of face rotating towards z axis rotation centre. In addition, application prototype also does not yet have a database to store attendance results. In this paper, a new application prototype has been developed using Eigenface face detection and recognition algorithm and Haar-based Cascade Classifier. Meanwhile, to overcome prototype performance weaknesses of the previously developed application, a pre-processing method was proposed in another study was added. Processes in the method were geometry transformation, histogram levelling separately, image smoothing using bilateral filtering, and elliptical masking. The test results showed that in the category of various environmental light intensity conditions, face recognition accuracy from developed application prototypes was 16.71% better than previous application prototypes. Meanwhile, in category of face slope conditions at z axis rotation centre, face recognition accuracy from developed application prototype was 38.47% better. Attendance database system was also successfully implemented and running without error.

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