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Color vision

Lesley W Chan, Daniel E Morse, Michael J Gordon
Near- and sub-wavelength photonic structures are used by numerous organisms (e.g., insects, cephalopods, fish, birds) to create vivid and often dynamically-tunable colors, as well as create, manipulate, or capture light for vision, communication, crypsis, photosynthesis, and defense. This review introduces the physics of moth eye (ME)-like, biomimetic nanostructures and discusses their application to reduce optical losses and improve efficiency of various optoelectronic devices, including photodetectors, photovoltaics, imagers, and light emitting diodes...
March 16, 2018: Bioinspiration & Biomimetics
Worapan Kusakunniran, Qiang Wu, Panrasee Ritthipravat, Jian Zhang
(Background and Objective): The occurrence of hard exudates is one of the early signs of diabetic retinopathy which is one of the leading causes of the blindness. Many patients with diabetic retinopathy lose their vision because of the late detection of the disease. Thus, this paper is to propose a novel method of hard exudates segmentation in retinal images in an automatic way. (Methods): The existing methods are based on either supervised or unsupervised learning techniques. In addition, the learned segmentation models may often cause miss-detection and/or fault-detection of hard exudates, due to the lack of rich characteristics, the intra-variations, and the similarity with other components in the retinal image...
May 2018: Computer Methods and Programs in Biomedicine
Peng Chen, Xiaohu Liu, Garima Goyal, Nhung Thi Tran, James Chin Shing Ho, Yi Wang, Daniel Aili, Bo Liedberg
Localized surface plasmon resonance (LSPR) constitutes a versatile technique for biodetection exploiting the sensitivity of plasmonic nanostructures to small changes in refractive index. The optical shift in the LSPR band caused by molecular in-teractions in the vicinity of the nanostructures are typically < 5 nm and can readily be detected using a spectrophotometer. Widespread use of LSPR based sensors require cost effective devices and would benefit from sensing schemes that enables use of very simple spectrophotometers or even naked eye detection...
March 15, 2018: Analytical Chemistry
Sabrina Pitzalis, Francesca Strappini, Alessandro Bultrini, Francesco Di Russo
Neuroimaging studies have identified so far, several color-sensitive visual areas in the human brain, and the temporal dynamics of these activities have been separately investigated using the visual-evoked potentials (VEPs). In the present study, we combined electrophysiological and neuroimaging methods to determine a detailed spatiotemporal profile of chromatic VEP and to localize its neural generators. The accuracy of the present co-registration study was obtained by combining standard fMRI data with retinotopic and motion mapping data at the individual level...
March 13, 2018: Human Brain Mapping
Xin Sun, Jennifer Young, Jeng-Hung Liu, David Newman
The objective of this project was to develop a computer vision system (CVS) for objective measurement of pork loin under industry speed requirement. Color images of pork loin samples were acquired using a CVS. Subjective color and marbling scores were determined according to the National Pork Board standards by a trained evaluator. Instrument color measurement and crude fat percentage were used as control measurements. Image features (18 color features; 1 marbling feature; 88 texture features) were extracted from whole pork loin color images...
March 7, 2018: Meat Science
Bo-Mi Song, Chi-Hon Lee
Many visual animals exploit spectral information for seeking food and mates, for identifying preys and predators, and for navigation. Animals use chromatic information in two ways. "True color vision," the ability to discriminate visual stimuli on the basis of their spectral content independent of brightness, is thought to play an important role in object identification. In contrast, "wavelength-specific behavior," which is strongly dependent on brightness, often associates with foraging, navigation, and other species-specific needs...
2018: Frontiers in Neural Circuits
Michael M Bannert, Andreas Bartels
Color is special among basic visual features in that it can form a defining part of objects that are engrained in our memory. Whereas most neuroimaging research on human color vision has focused on responses related to external stimulation, the present study investigated how sensory-driven color vision is linked to subjective color perception induced by object imagery. We recorded fMRI activity in male and female volunteers during viewing of abstract color stimuli that were red, green, or yellow in half of the runs...
March 8, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Katherine G Gold, Stacy Scofield, Steven R Isaacson, Michael W Stewart, Michael Kazim
PURPOSE: To evaluate the effectiveness of orbital radiotherapy (ORT) in the treatment of thyroid eye disease (TED)-compressive optic neuropathy. METHODS: A retrospective review of patients with corticosteroid-responsive compressive optic neuropathy due to TED treated with ORT. Study was conducted in compliance with Health Insurance Portability and Accountability Act. One hundred four patients (163 orbits) with a mean age of 61.7 years met inclusion criteria. Seventy-four percent (77/104) were female, and 32...
March 2018: Ophthalmic Plastic and Reconstructive Surgery
Dimitrios Karagiannis, George Kontadakis, Dimitrios Brouzas, Marilita Moschos, Alexandros Damanakis
Purpose: To describe a case of a child with nonorganic visual loss due to school bullying. Observations: An eight-year-old boy presented with bilateral painless vision loss for a few days. His best corrected visual acuity (BCVA) was 20/200 in the right eye and 20/140 in the left eye. Color vision was normal. Fundoscopy, visual fields, electroretinography, electrooculography and visual evoked potentials were within normal limits. A nonorganic (psychogenic) cause of visual loss was suspected...
April 2017: American Journal of Ophthalmology Case Reports
Claudia Gonzalez Viejo, Sigfredo Fuentes, Kate Howell, Damir D Torrico, Frank R Dunshea
Traditional sensory tests rely on conscious and self-reported responses from participants. The integration of non-invasive biometric techniques, such as heart rate, body temperature, brainwaves and facial expressions can gather more information from consumers while tasting a product. The main objectives of this study were i) to assess significant differences between beers for all conscious and unconscious responses, ii) to find significant correlations among the different variables from the conscious and unconscious responses and iii) to develop a model to classify beers according to liking using only the unconscious responses...
February 28, 2018: Physiology & Behavior
Cagri Ilhan, Mehmet Ali Sekeroglu, Sibel Doguizi, Pelin Yilmazbas
PURPOSE: To investigate the static and dynamic contrast sensitivity (CS) of patients with congenital red-green color vision deficiency (CVD) and to compare these values with those of healthy control subjects. METHODS: The study included 25 subjects with congenital CVD (10 with strong protan defect and 15 with strong deutan defect) and 20 age- and gender-matched healthy subjects. Following detailed ophthalmological examination, monocular static and dynamic CS measurements were taken with the Monpack3 device (Metrovision, Perenchies, France) on all subjects...
March 2, 2018: International Ophthalmology
Mustafa Eren, Murat Kucukevcilioglu, Ali Hakan Durukan
PURPOSE: To examine retinal sensitivity in patients on hydroxychloroquine (HCQ) with no evidence of retinopathy. MATERIALS AND METHODS: 70 patients on HCQ and 30 healthy control subjects were included prospectively. All subjects underwent complete ophthalmic examination including best corrected visual acuity, tonometry, color vision testing, biomicroscopy of anterior segment, dilated fundoscopy, 10-2 visual field testing and Spectral domain optical coherence tomography...
March 1, 2018: Cutaneous and Ocular Toxicology
Malke Asaad, Samita Goyal, Kristen A Klement, Arlen D Denny
Crouzon syndrome (CS) is one of the craniosynostosis syndromes that leads to early fusion of cranial sutures and increased intracranial pressure. Intracranial hypertension is a serious complication that may lead to vision loss and cognitive impairment. Early detection and management are necessary to prevent complications. The authors present a patient with CS who underwent posterior cranial vault reconstruction with internal distraction after multiple episodes of headache and papilledema. The patient was unaware of any loss of color vision before the surgery; however, he noted an improvement in his color vision after the surgery...
February 26, 2018: Journal of Craniofacial Surgery
Tingzhu Wu, Yue Lin, Lili Zheng, Ziquan Guo, Jianxing Xu, Shijie Liang, Zhuguagn Liu, Yijun Lu, Tien-Mo Shih, Zhong Chen
An optimal design of light-emitting diode (LED) lighting that benefits both the photosynthesis performance for plants and the visional health for human eyes has drawn considerable attention. In the present study, we have developed a multi-color driving algorithm that serves as a liaison between desired spectral power distributions and pulse-width-modulation duty cycles. With the aid of this algorithm, our multi-color plant-growth light sources can optimize correlated-color temperature (CCT) and color rendering index (CRI) such that photosynthetic luminous efficacy of radiation (PLER) is maximized regardless of the number of LEDs and the type of photosynthetic action spectrum (PAS)...
February 19, 2018: Optics Express
Rupak Roy, Kumar Saurabh, Nicey R Thomas
PURPOSE: To describe multicolor imaging findings in a case of acute retinal pigment epitheliitis. SETTING: Vitreoretinal department of a tertiary care center in Eastern India. METHODS: A 28-year-old lady presented with acute vision loss in the right eye since 3 days. Left eye examination was unremarkable. Best-corrected visual acuity in the right eye was 20/40. Anterior segment examination revealed clear lens with no evidence of inflammation...
February 22, 2018: Retinal Cases & Brief Reports
Marko Ilić, Andrej Meglič, Marko Kreft, Gregor Belušič
Microvillar photoreceptors are intrinsically capable of detecting the orientation of e-vector of linearly polarized light. They provide most invertebrates with an additional sensory channel to detect important features of their visual environment. However, polarization sensitivity (PS) of photoreceptors may lead to the detection of polarization-induced false colors and intensity contrasts. Most insect photoreceptors are thus adapted to have minimal PS. Flies have twisted rhabdomeres with microvilli rotated along the length of the ommatidia to reduce PS...
2018: Frontiers in Cellular Neuroscience
Amit Sethi, Lingdao Sha, Neeraj Kumar, Virgilia Macias, Ryan J Deaton, Peter H Gann
OBJECTIVE: To determine whether a computer vision-based approach applied to H&E prostate biopsy images can distinguish dutasteride-treated tissue from placebo, and identify features associated with degree of responsiveness to 5α-reductase inhibitor (5ARI) therapy. SUBJECTS AND METHODS: Our study population comprised 100 treatment-compliant men without prostate cancer assigned to dutasteride or placebo in the REDUCE trial who had slides available from mandatory Year 4 biopsies...
February 20, 2018: BJU International
Da-Ke Li, Feng-Tao Liu, Kui Chen, Lu-Lu Bu, Ke Yang, Chen Chen, Zhen-Yang Liu, Yi-Lin Tang, Jue Zhao, Yi-Min Sun, Jian Wang, Jian-Jun Wu
Depressive symptoms and sensory dysfunction, such as reduction in visual and olfactory function, are common in Parkinson's disease (PD). Previous studies have suggested that depressive symptoms are associated with visual impairments and potentially with hyposmia in several types of mood disorders. However, the relationship between depressive symptoms and sensory dysfunction remains unclear in PD. To examine the association of depressive symptoms with color vision and olfactory function in PD, the authors conducted a cross-sectional study in 159 patients with PD...
February 20, 2018: Journal of Neuropsychiatry and Clinical Neurosciences
Hanlu Twyman, Staffan Andersson, Nicholas I Mundy
BACKGROUND: Exaggerated signals, such as brilliant colours, are usually assumed to evolve through antagonistic coevolution between senders and receivers, but the underlying genetic mechanisms are rarely known. Here we explore a recently identified "redness gene", CYP2J19, that is highly interesting in this context since it encodes a carotenoid-modifying enzyme (a C4 ketolase involved in both colour signalling and colour discrimination in the red (long wavelength) spectral region...
February 13, 2018: BMC Evolutionary Biology
Amirhossein Aghamohammadi, Mei Choo Ang, Elankovan A Sundararajan, Ng Kok Weng, Marzieh Mogharrebi, Seyed Yashar Banihashem
Visual tracking in aerial videos is a challenging task in computer vision and remote sensing technologies due to appearance variation difficulties. Appearance variations are caused by camera and target motion, low resolution noisy images, scale changes, and pose variations. Various approaches have been proposed to deal with appearance variation difficulties in aerial videos, and amongst these methods, the spatiotemporal saliency detection approach reported promising results in the context of moving target detection...
2018: PloS One
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