Test–Retest Repeatability of the Pupil Light Response to Blue and Red Light Stimuli in Normal Human Eyes Using a Novel Pupillometer

AbstractWe have mapped quantitative trait loci (QTL) responsible for natural variation in light and hormone response between the Cape Verde Islands (Cvi) and Landsberg erecta (Ler) accessions of Arabidopsis thaliana using recombinant inbred lines (RILs). Hypocotyl length was measured in four light environments: white, blue, red, and far-red light and in the dark. In addition, white light plus gibberellin (GA) and dark plus the brassinosteroid biosynthesis inhibitor brassinazole (BRZ) were used to detect hormone effects. Twelve QTL were identified that map to loci not previously known to affect light response, as well as loci where candidate genes have been identified from known mutations. Some QTL act in all environments while others show genotype-by-environment interaction. A global threshold was established to identify a significant epistatic interaction between two loci that have few main effects of their own. LIGHT1, a major QTL, has been confirmed in a near isogenic line (NIL) and maps to a new locus with effects in all light environments. The erecta mutation can explain the effect of the HYP2 QTL in the blue, BRZ, and dark environments, but not in far-red. LIGHT2, also confirmed in an NIL, has effects in white and red light and shows interaction with GA. The phenotype and map position of LIGHT2 suggest the photoreceptor PHYB as a candidate gene. Natural variation in light and hormone response thus defines both new genes and known genes that control light response in wild accessions.

Download Full-text

A Generator of Peroxynitrite Activatable with Red Light

Chemical Science ◽

10.1039/d0sc06970a ◽

2021 ◽

Author(s):

Cristina Parisi ◽

Mariacristina Failla ◽

Aurore Fraix ◽

Luca Menilli ◽

Francesca Moret ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Reactive Nitrogen Species ◽

Red Light ◽

Reactive Oxygen ◽

Reactive Nitrogen ◽

Oxygen Species ◽

Nitrogen Species ◽

New Horizons ◽

Light Stimuli ◽

Spatiotemporal Control

The generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) as “unconventional” therapeutics with precise spatiotemporal control by using light stimuli may open entirely new horizons for innovative...

Download Full-text

Zebrafish automatic monitoring system for conditioning and behavioral analysis

Scientific Reports ◽

10.1038/s41598-021-87502-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Marta de Oliveira Barreiros ◽

Felipe Gomes Barbosa ◽

Diego de Oliveira Dantas ◽

Daniel de Matos Luna dos Santos ◽

Sidarta Ribeiro ◽

...

Keyword(s):

Video Processing ◽

Red Light ◽

Automatic Monitoring ◽

Automated System ◽

Control Group ◽

Automatic Monitoring System ◽

Fish Schools ◽

Detection And Tracking ◽

Evaluation Strategies ◽

Light Stimuli

AbstractStudies using zebrafish (Danio rerio) in neuro-behavioural research are growing. Measuring fish behavior by computational methods is one of the most efficient ways to avoid human bias in experimental analyses, extending them to various approaches. Sometimes, thorough analyses are difficult to do, as fish can behave unpredictably during an experimental strategy. However, the analyses can be implemented in an automated way, using an online strategy and video processing for a complete assessment of the zebrafish behavior, based on the detection and tracking of fish during an activity. Here, a fully automatic conditioning and detailed analysis of zebrafish behavior is presented. Microcontrolled components were used to control the delivery of visual and sound stimuli, in addition to the concise amounts of food after conditioned stimuli for adult zebrafish groups in a conventional tank. The images were captured and processed for automatic detection of the fish, and the training of the fish was done in two evaluation strategies: simple and complex. In simple conditioning, the zebrafish showed significant responses from the second attempt, learning that the conditioned stimulus was a predictor of food presentation in a specific space of the tank, where the food was dumped. When the fish were subjected to two stimuli for decision-making in the food reward, the zebrafish obtained better responses to red light stimuli in relation to vibration. The behavior change was clear in stimulated fish in relation to the control group, thus, the distances traveled and the speed were greater, while the polarization was lower in stimulated fish. This automated system allows for the conditioning and assessment of zebrafish behavior online, with greater stability in experiments, and in the analysis of the behavior of individual fish or fish schools, including learning and memory studies.

Download Full-text

Improvement of red light response of Cu2Sn1−xGexS3 solar cells by optimization of CdS buffer layers

Journal of Applied Physics ◽

10.1063/1.4933269 ◽

2015 ◽

Vol 118 (15) ◽

pp. 154502 ◽

Cited By ~ 8

Author(s):

Mitsutaro Umehara ◽

Yasuhiko Takeda ◽

Shin Tajima ◽

Tomoyoshi Motohiro ◽

Takenobu Sakai ◽

...

Keyword(s):

Solar Cells ◽

Red Light ◽

Light Response ◽

Buffer Layers

Download Full-text

Deep learning-based pupil model predicts time and spectral dependent light responses

Scientific Reports ◽

10.1038/s41598-020-79908-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Babak Zandi ◽

Tran Quoc Khanh

Keyword(s):

Deep Learning ◽

Time Course ◽

Light Response ◽

Absolute Error ◽

Light Responses ◽

Temporal Prediction ◽

Feed Forward Neural Networks ◽

Self Learning ◽

Pupil Light Response ◽

Planckian Locus

AbstractAlthough research has made significant findings in the neurophysiological process behind the pupillary light reflex, the temporal prediction of the pupil diameter triggered by polychromatic or chromatic stimulus spectra is still not possible. State of the art pupil models rested in estimating a static diameter at the equilibrium-state for spectra along the Planckian locus. Neither the temporal receptor-weighting nor the spectral-dependent adaptation behaviour of the afferent pupil control path is mapped in such functions. Here we propose a deep learning-driven concept of a pupil model, which reconstructs the pupil’s time course either from photometric and colourimetric or receptor-based stimulus quantities. By merging feed-forward neural networks with a biomechanical differential equation, we predict the temporal pupil light response with a mean absolute error below 0.1 mm from polychromatic (2007 $$\pm$$ ± 1 K, 4983 $$\pm$$ ± 3 K, 10,138 $$\pm$$ ± 22 K) and chromatic spectra (450 nm, 530 nm, 610 nm, 660 nm) at 100.01 ± 0.25 cd/m2. This non-parametric and self-learning concept could open the door to a generalized description of the pupil behaviour.

Download Full-text

Comparison of corneal irregular astigmatism by the type of corneal regular astigmatism

Scientific Reports ◽

10.1038/s41598-021-95358-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yuta Ueno ◽

Risa Nomura ◽

Takahiro Hiraoka ◽

Katsuhito Kinoshita ◽

Mutsuko Ohara ◽

...

Keyword(s):

Higher Order ◽

Stepwise Multiple Regression ◽

Group Differences ◽

Corneal Surface ◽

Fourier Harmonic ◽

Normal Human ◽

The Mean ◽

Human Eyes ◽

Topography Data ◽

Irregular Astigmatism

AbstractWe investigated the relation between corneal regular and irregular astigmatism in normal human eyes. In 951 eyes of 951 patients, corneal irregular astigmatism, such as asymmetry and higher-order irregularity components, was calculated using the Fourier harmonic analysis of corneal topography data within the central 3-mm zone of the anterior corneal surface. The eyes were classified by the type of corneal regular astigmatism into four groups; minimum (< 0.75 diopters), with-the-rule (WTR), against-the-rule (ATR), and oblique astigmatism. The mean age was significantly different among the four groups (P < 0.001); patients with WTR astigmatism were the youngest, followed by those with minimum, oblique, and ATR astigmatism. Significant inter-group differences were found among the four groups in asymmetry (P = 0.005) and higher-order irregularity components (P < 0.001); the largest was in eyes with oblique astigmatism, followed by ATR, WTR, and minimum astigmatism. The stepwise multiple regression analysis revealed that corneal regular astigmatism pattern significantly influenced the amount of corneal irregular astigmatism after controlling for confounding factors (P < 0.001). Corneal irregular astigmatism, such as asymmetry and higher order irregularity components, was the largest in eyes with oblique astigmatism, followed by those with ATR, WTR, and minimum astigmatism, even after adjustment for age of subjects.

Download Full-text

“Emmetropic, but not myopic human eyes distinguish positive defocus from calculated defocus in monochromatic red light”

Vision Research ◽

10.1016/j.visres.2021.107974 ◽

2022 ◽

Vol 192 ◽

pp. 107974

Author(s):

Barbara Swiatczak ◽

Frank Schaeffel

Keyword(s):

Red Light ◽

Human Eyes

Download Full-text

Light-evoked contraction of red absorbing cones in the Xenopus retina is maximally sensitive to green light

Visual Neuroscience ◽

10.1017/s0952523800002893 ◽

1992 ◽

Vol 8 (3) ◽

pp. 243-249 ◽

Cited By ~ 12

Author(s):

Joseph C. Besharse ◽

Paul Witkovsky

Keyword(s):

Xenopus Laevis ◽

Spectral Sensitivity ◽

Red Light ◽

Green Light ◽

Sensitivity Function ◽

Direct Mechanism ◽

Sensitivity Experiments ◽

Light Stimuli ◽

The Difference ◽

Spectral Sensitivity Function

AbstractTo test the hypothesis that light-evoked cone contraction in eye cups from Xenopus laevis is controlled through a direct mechanism initiated by the cone's own photopigment, we conducted spectral-sensitivity experiments. We estimate that initiation of contraction of red absorbing cones (611 nm) is 1.5 log units more sensitive to green (533 nm) than red (650 nm) light stimuli. The difference is comparable to that predicted from the spectral-sensitivity function of the green absorbing, principal rod (523 nm). Furthermore, 480-nm and 580-nm stimuli which are absorbed nearly equally by the principal rod have indistinguishable effects on cone contraction. We also found that light blockade of nighttime cone elongation is much more sensitive to green than to red light stimuli. Our observations are inconsistent with the hypothesis tested, and suggest that light-regulated cone motility is controlled through an indirect mechanism initiated primarily by the green absorbing, principal rod.

Download Full-text