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https://www.readbyqxmd.com/read/28444297/rapid-and-parallel-adaptive-evolution-of-the-visual-system-of-neotropical-midas-cichlid-fishes
#1
Julián Torres-Dowdall, Michele E R Pierotti, Andreas Härer, Nidal Karagic, Joost M Woltering, Frederico Henning, Kathryn R Elmer, Axel Meyer
Midas cichlid fish are a Central American species flock containing 13 described species that has been dated to only few thousand years old, a historical timescale infrequently associated with speciation. Their radiation involved the colonization of several clear water crater lakes from two turbid great lakes. Therefore, Midas cichlids have been subjected to widely varying photic conditions during their radiation. Being a primary signal relay for information from the environment to the organism, the visual system is under continuing selective pressure and a prime organ system for accumulating adaptive changes during speciation, particularly in the case of dramatic shifts in photic conditions...
April 21, 2017: Molecular Biology and Evolution
https://www.readbyqxmd.com/read/28442402/chromatic-clocks-color-opponency-in-non-image-forming-visual-function-review
#2
REVIEW
Manuel Spitschan, Robert J Lucas, Timothy M Brown
During dusk and dawn, the ambient illumination undergoes drastic changes in irradiance (or intensity) and spectrum (or color). While the former is a well-studied factor in synchronizing behavior and physiology to the earth's 24-hour rotation, color sensitivity in the regulation of circadian rhythms has not been systematically studied. Drawing on the concept of color opponency, a well-known property of image-forming vision in many vertebrates (including humans), we consider how the spectral shifts during twilight are encoded by a color-opponent sensory system for non-image-forming (NIF) visual functions including phase shifting and melatonin suppression...
April 22, 2017: Neuroscience and Biobehavioral Reviews
https://www.readbyqxmd.com/read/28420197/a-novel-auto-sorting-system-for-chinese-cabbage-seeds
#3
Kuo-Yi Huang, Jian-Feng Cheng
This paper presents a novel machine vision-based auto-sorting system for Chinese cabbage seeds. The system comprises an inlet-outlet mechanism, machine vision hardware and software, and control system for sorting seed quality. The proposed method can estimate the shape, color, and textural features of seeds that are provided as input neurons of neural networks in order to classify seeds as "good" and "not good" (NG). The results show the accuracies of classification to be 91.53% and 88.95% for good and NG seeds, respectively...
April 18, 2017: Sensors
https://www.readbyqxmd.com/read/28420134/visual-detection-and-tracking-system-for-a-spherical-amphibious-robot
#4
Shuxiang Guo, Shaowu Pan, Liwei Shi, Ping Guo, Yanlin He, Kun Tang
With the goal of supporting close-range observation tasks of a spherical amphibious robot, such as ecological observations and intelligent surveillance, a moving target detection and tracking system was designed and implemented in this study. Given the restrictions presented by the amphibious environment and the small-sized spherical amphibious robot, an industrial camera and vision algorithms using adaptive appearance models were adopted to construct the proposed system. To handle the problem of light scattering and absorption in the underwater environment, the multi-scale retinex with color restoration algorithm was used for image enhancement...
April 15, 2017: Sensors
https://www.readbyqxmd.com/read/28417832/color-vision-in-color-display-night-vision-goggles
#5
Eric P Liggins, William P Serle
INTRODUCTION: Aircrew viewing eyepiece-injected symbology on color display night vision goggles (CDNVGs) are performing a visual task involving color under highly unnatural viewing conditions. Their performance in discriminating different colors and responding to color cues is unknown. METHODS: Experimental laboratory measurements of 1) color discrimination and 2) visual search performance are reported under adaptation conditions representative of a CDNVG. Color discrimination was measured using a two-alternative forced choice (2AFC) paradigm that probes color space uniformly around a white point...
May 1, 2017: Aerospace Medicine and Human Performance
https://www.readbyqxmd.com/read/28413768/surgical-resection-of-an-optic-nerve-sheath-meningioma-relevance-of-endoscopic-endonasal-approaches-to-the-optic-canal
#6
Patrick J Hunt, Franco DeMonte, Rosa A Tang, Shirley Y Su, Shaan M Raza
Optic nerve sheath meningiomas (ONSMs) account for less than 2% of meningiomas and 1.7% of orbital tumors. Although rare, the management of these tumors is important as unilateral blindness often results in untreated cases. Radiotherapy has emerged as the preferred treatment. However, therapies for ONSMs are controversial due to the variable natural history of the disease and limitations of surgical and radiotherapy options. A 60-year-old woman presented with monocular left diminished color perception and blurred vision...
April 2017: Journal of Neurological Surgery Reports
https://www.readbyqxmd.com/read/28411334/normative-values-for-a-tablet-computer-based-application-to-assess-chromatic-contrast-sensitivity
#7
Lakshmi Bodduluri, Mei Ying Boon, Malcolm Ryan, Stephen J Dain
Tablet computer displays are amenable for the development of vision tests in a portable form. Assessing color vision using an easily accessible and portable test may help in the self-monitoring of vision-related changes in ocular/systemic conditions and assist in the early detection of disease processes. Tablet computer-based games were developed with different levels of gamification as a more portable option to assess chromatic contrast sensitivity. Game 1 was designed as a clinical version with no gaming elements...
April 14, 2017: Behavior Research Methods
https://www.readbyqxmd.com/read/28406471/real-time-vision-based-road-sign-recognition-using-an-artificial-neural-network
#8
Kh Tohidul Islam, Ram Gopal Raj
Road sign recognition is a driver support function that can be used to notify and warn the driver by showing the restrictions that may be effective on the current stretch of road. Examples for such regulations are 'traffic light ahead' or 'pedestrian crossing' indications. The present investigation targets the recognition of Malaysian road and traffic signs in real-time. Real-time video is taken by a digital camera from a moving vehicle and real world road signs are then extracted using vision-only information...
April 13, 2017: Sensors
https://www.readbyqxmd.com/read/28405391/red-fluorescence-of-the-triplefin-tripterygion-delaisi-is-increasingly-visible-against-background-light-with-increasing-depth
#9
Pierre-Paul Bitton, Ulrike K Harant, Roland Fritsch, Connor M Champ, Shelby E Temple, Nico K Michiels
The light environment in water bodies changes with depth due to the absorption of short and long wavelengths. Below 10 m depth, red wavelengths are almost completely absent rendering any red-reflecting animal dark and achromatic. However, fluorescence may produce red coloration even when red light is not available for reflection. A large number of marine taxa including over 270 fish species are known to produce red fluorescence, yet it is unclear under which natural light environment fluorescence contributes perceptively to their colours...
March 2017: Royal Society Open Science
https://www.readbyqxmd.com/read/28405186/color-representation-is-retinotopically-biased-but-locally-intermingled-in-mouse-v1
#10
Shuhei Aihara, Takashi Yoshida, Takayuki Hashimoto, Kenichi Ohki
Dichromatic vision is common in many mammals. However, color processing in the primary visual cortex (V1) of dichromatic mammals is relatively unknown compared to the trichromatic primates. In this study, we investigated the functional organization of color processing in mouse V1. The mouse retina has a graded expression pattern of two opsins along its dorsoventral axis. However, it is not clear whether and how this expression pattern is reflected in the cortical representation at local (several hundred microns) and areal (V1) level...
2017: Frontiers in Neural Circuits
https://www.readbyqxmd.com/read/28399148/convergent-evolution-of-sws2-opsin-facilitates-adaptive-radiation-of-threespine-stickleback-into-different-light-environments
#11
David A Marques, John S Taylor, Felicity C Jones, Federica Di Palma, David M Kingsley, Thomas E Reimchen
Repeated adaptation to a new environment often leads to convergent phenotypic changes whose underlying genetic mechanisms are rarely known. Here, we study adaptation of color vision in threespine stickleback during the repeated postglacial colonization of clearwater and blackwater lakes in the Haida Gwaii archipelago. We use whole genomes from 16 clearwater and 12 blackwater populations, and a selection experiment, in which stickleback were transplanted from a blackwater lake into an uninhabited clearwater pond and resampled after 19 y to test for selection on cone opsin genes...
April 2017: PLoS Biology
https://www.readbyqxmd.com/read/28385798/visual-acuity-and-signal-color-pattern-in-an-anolis-lizard
#12
Leo J Fleishman, Anna I Yeo, Carley W Perez
Anolis lizards communicate with colorful dewlaps that often include detailed patterns. We measured the visual acuity of Anolis sagrei. Lizards viewed a checkerboard pattern of red and yellow-green squares that were too small to resolve, and thus appeared uniform in color. We quickly replaced the center portion of the display with a pattern of larger squares. If the new pattern could be resolved, the lizards perceived a change in color and reflexively shifted gaze toward the target. The acuity threshold was 1...
April 6, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28384671/acute-zonal-cone-photoreceptor-outer-segment-loss
#13
Tomas S Aleman, Harpal S Sandhu, Leona W Serrano, Anastasia Traband, Marisa K Lau, Grazyna Adamus, Robert A Avery
Importance: The diagnostic path presented narrows down the cause of acute vision loss to the cone photoreceptor outer segment and will refocus the search for the cause of similar currently idiopathic conditions. Objective: To describe the structural and functional associations found in a patient with acute zonal occult photoreceptor loss. Design, Setting, and Participants: A case report of an adolescent boy with acute visual field loss despite a normal fundus examination performed at a university teaching hospital...
April 6, 2017: JAMA Ophthalmology
https://www.readbyqxmd.com/read/28375334/evaluation-of-whiteness-formulas-for-fwa-and-non-fwa-whites
#14
Minchen Wei, Shining Ma, Yuzhao Wang, Ming Ronnier Luo
Whiteness is an important colorimetric characteristic for surface colors. Currently, the CIE whiteness formula is widely used to characterize the whiteness of a surface in industry, whose limitations have been well documented. In this study, the whiteness appearance of 55 textile samples [43 non-fluorescent whitening agents (FWAs) and 12 FWA samples] were evaluated under six lighting conditions, comprising three levels of correlated color temperature (CCT) (i.e., 3000, 4000, and 6500 K) and two levels of UV radiation (i...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28375322/transformation-of-a-high-dimensional-color-space-for-material-classification
#15
Huajian Liu, Sang-Heon Lee, Javaan Singh Chahl
Images in red-green-blue (RGB) color space need to be transformed to other color spaces for image processing or analysis. For example, the well-known hue-saturation-intensity (HSI) color space, which separates hue from saturation and intensity and is similar to the color perception of humans, can aid many computer vision applications. For high-dimensional images, such as multispectral or hyperspectral images, transformation images to a color space that can separate hue from saturation and intensity would be useful; however, the related works are limited...
April 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/28371095/performance-of-dental-students-in-shade-matching-impact-of-training
#16
Adriana P Buhrer Samra, Marcella G Moro, Rui F Mazur, Sergio Vieira, Evelise M De Souza, Andrea Freire, Rodrigo N Rached
OBJECTIVE: The present study evaluated the effect of training on dental students' ability for matching two different shade guides. MATERIALS AND METHODS: The study was conducted in 2012. The participants were 88 male and female undergraduate dental students from Brazil and Portugal, with or without previous color education and vision refractive errors (response rate of 73.33%). They were asked to match a pair set of the shade guides Vita Classical (VC) and Vitapan 3D Master (3DM), with a 20-minutes' rest between each match...
April 2017: Journal of Esthetic and Restorative Dentistry
https://www.readbyqxmd.com/read/28366503/benign-yellow-dot-maculopathy-a-new-macular-phenotype
#17
Arundhati Dev Borman, Aleksandra Rachitskaya, Martina Suzani, Robert A Sisk, Zubair M Ahmed, Graham E Holder, Valentina Cipriani, Gavin Arno, Andrew R Webster, Robert B Hufnagel, Audina Berrocal, Anthony T Moore
PURPOSE: To describe a novel macular phenotype that is associated with normal visual function. DESIGN: Retrospective, observational case series. PARTICIPANTS: Thirty-six affected individuals from 23 unrelated families. METHODS: This was a retrospective study of patients who had a characteristic macular phenotype. Subjects underwent a full ocular examination, electrophysiologic studies, spectral-domain optical coherence tomography (OCT), and fundus autofluorescence imaging...
March 30, 2017: Ophthalmology
https://www.readbyqxmd.com/read/28359545/automated-identification-of-diabetic-retinopathy-using-deep-learning
#18
Rishab Gargeya, Theodore Leng
PURPOSE: Diabetic retinopathy (DR) is one of the leading causes of preventable blindness globally. Performing retinal screening examinations on all diabetic patients is an unmet need, and there are many undiagnosed and untreated cases of DR. The objective of this study was to develop robust diagnostic technology to automate DR screening. Referral of eyes with DR to an ophthalmologist for further evaluation and treatment would aid in reducing the rate of vision loss, enabling timely and accurate diagnoses...
March 27, 2017: Ophthalmology
https://www.readbyqxmd.com/read/28359140/gold-nanoparticles-as-a-direct-and-rapid-sensor-for-sensitive-analytical-detection-of-biogenic-amines
#19
K M A El-Nour, E T A Salam, H M Soliman, A S Orabi
A new optical sensor was developed for rapid screening with high sensitivity for the existence of biogenic amines (BAs) in poultry meat samples. Gold nanoparticles (GNPs) with particle size 11-19 nm function as a fast and sensitive biosensor for detection of histamine resulting from bacterial decarboxylation of histidine as a spoilage marker for stored poultry meat. Upon reaction with histamine, the red color of the GNPs converted into deep blue. The appearance of blue color favorably coincides with the concentration of BAs that can induce symptoms of poisoning...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28358949/myopia-and-late-onset-progressive-cone-dystrophy-associate-to-lvava-mvava-exon-3-interchange-haplotypes-of-opsin-genes-on-chromosome-x
#20
Orsolya Orosz, István Rajta, Attila Vajas, Lili Takács, Adrienne Csutak, Mariann Fodor, Bence Kolozsvári, Miklós Resch, Katalin Sényi, Balázs Lesch, Viktória Szabó, András Berta, István Balogh, Gergely Losonczy
Purpose: Rare interchange haplotypes in exon 3 of the OPN1LW and OPN1MW opsin genes cause X-linked myopia, color vision defect, and cone dysfunction. The severity of the disease varies on a broad scale from nonsyndromic high myopia to blue cone monochromatism. Here, we describe a new genotype-phenotype correlation attributed to rare exon 3 interchange haplotypes simultaneously present in the long- and middle-wavelength sensitive opsin genes (L- and M-opsin genes). Methods: A multigenerational family with X-linked high myopia and cone dystrophy was investigated...
March 1, 2017: Investigative Ophthalmology & Visual Science
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