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Color contrast sensitivity

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https://www.readbyqxmd.com/read/28533455/coevolution-of-coloration-and-colour-vision
#1
Olle Lind, Miriam J Henze, Almut Kelber, Daniel Osorio
The evolutionary relationship between signals and animal senses has broad significance, with potential consequences for speciation, and for the efficacy and honesty of biological communication. Here we outline current understanding of the diversity of colour vision in two contrasting groups: the phylogenetically conservative birds, and the more variable butterflies. Evidence for coevolution of colour signals and vision exists in both groups, but is limited to observations of phenotypic differences between visual systems, which might be correlated with coloration...
July 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28527199/the-value-of-contrast-enhanced-ultrasound-ceus-using-a-high-end-ultrasound-system-in-the-characterization-of-endoleaks-after-endovascular-aortic-repair-evar
#2
J Rübenthaler, M Reiser, V Cantisani, D Rjosk-Dendorfer, D A Clevert
PURPOSE: To evaluate the value of contrast-enhanced ultrasound (CEUS) using a high-end ultrasound system in the characterization of endoleaks after endovascular aortic repair (EVAR). MATERIAL AND METHODS: In this mono-center study, 41 patients were retrospectively analyzed after being examined using a modern high-end ultrasound system (RS80A with Prestige, Samsung Medison Co., Ltd., Seoul, Korea). The maximum diameters of the aneurysms were measured in two planes (right-left and ventral-dorsal)...
May 18, 2017: Clinical Hemorheology and Microcirculation
https://www.readbyqxmd.com/read/28526539/diagnostic-accuracy-of-lung-subtraction-iodine-mapping-ct-for-the-evaluation-of-pulmonary-perfusion-in-patients-with-chronic-thromboembolic-pulmonary-hypertension-correlation-with-perfusion-spect-ct
#3
Masashi Tamura, Yoshitake Yamada, Takashi Kawakami, Masaharu Kataoka, Yu Iwabuchi, Hiroaki Sugiura, Masahiro Hashimoto, Tadaki Nakahara, Shigeo Okuda, Seishi Nakatsuka, Fumiya Sano, Takayuki Abe, Yuichiro Maekawa, Keiichi Fukuda, Masahiro Jinzaki
BACKGROUND: For treatment of chronic thromboembolic pulmonary hypertension (CTEPH), the evaluation of segmental pulmonary perfusion is important. There are no previous reports about lung subtraction iodine mapping (LSIM) computed tomography (CT) for evaluation of segmental pulmonary perfusion in patients with CTEPH, using lung perfusion SPECT/CT (LPS) as the reference. METHODS: 50 patients (age, 60.7±16.7years) with known or suspected CTEPH were enrolled in this study...
May 4, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28506064/ice-melting-dynamics-the-role-of-protons-and-interfacial-geometry
#4
Andrew J Schwartz, Gerald H Pollack
The surface of ice plays a significant role in melting. To better understand the role of the surface, we studied the melting of ice using infrared imaging and pH-sensitive dyes. Ice was allowed to melt in baths of water of varying depth. When the ice melted in a high level of room-temperature water, equal to the height of the ice, the conventional melting pattern appeared. When the ice melted in a chamber with a lower water level, the melting pattern was unexpected. Seconds after the ice was placed in the water, localized regions of low temperature water appeared around the perimeter of the ice...
May 15, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28479109/fuzzy-spectral-clustering-for-automated-delineation-of-chronic-wound-region-using-digital-images
#5
Dhiraj Manohar Dhane, Maitreya Maiti, Tushar Mungle, Chittaranjan Bar, Arun Achar, Maheshkumar Kolekar, Chandan Chakraborty
Chronic wound is an abnormal disease condition of localized injury to the skin and its underlying tissues having physiological impaired healing response. Assessment and management of such wound is a significant burden on the healthcare system. Currently, precise wound bed estimation depends on the clinical judgment and remains a difficult task. The paper introduces a novel method for ulcer boundary demarcation and estimation, using optical images captured by a hand-held digital camera. The proposed approach involves gray based fuzzy similarity measure using spatial knowledge of an image...
April 23, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28474130/blood-vessel-segmentation-in-color-fundus-images-based-on-regional-and-hessian-features
#6
Syed Ayaz Ali Shah, Tong Boon Tang, Ibrahima Faye, Augustinus Laude
PURPOSE: To propose a new algorithm of blood vessel segmentation based on regional and Hessian features for image analysis in retinal abnormality diagnosis. METHODS: Firstly, color fundus images from the publicly available database DRIVE were converted from RGB to grayscale. To enhance the contrast of the dark objects (blood vessels) against the background, the dot product of the grayscale image with itself was generated. To rectify the variation in contrast, we used a 5 × 5 window filter on each pixel...
May 4, 2017: Graefe's Archive for Clinical and Experimental Ophthalmology
https://www.readbyqxmd.com/read/28451159/dual-emissive-nanoarchitecture-of-lanthanide-complex-modified-silica-particles-for-in-vivo-ratiometric-time-gated-luminescence-imaging-of-hypochlorous-acid
#7
Hua Ma, Bo Song, Yuanxiu Wang, Deyuan Cong, Yufei Jiang, Jingli Yuan
We have developed a ratiometric time-gated luminescence sensory system for in vivo imaging of hypochlorous acid (HClO) by preparing a dual-emissive nanoarchitecture of europium- and terbium-complex-modified silica nanoparticles. The design of this nanoarchitecture is based on our new finding that the strong, long-lived luminescence of the β-diketonate-Eu(3+) complex can be rapidly and selectively quenched by HClO. Therefore, the β-diketonate-Eu(3+) complex was decorated on the surface of the silica nanoparticles for responding to HClO, while a HClO-insensitive luminescent terbium complex was immobilized in the inner solid core of the nanoparticles to serve as an internal standard...
January 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28446838/visual-functions-of-workers-exposed-to-organic-solvents-in-petrochemical-industries
#8
R Indhushree, R Monica, K Coral, Narayanasamy Angayarkanni, R Punitham, B M Subburathinam, R Krishnakumar, P P Santanam
AIM: The purpose of this study was to evaluate the visual functions of workers exposed to organic solvents in petrochemical industries. MATERIALS AND METHODS: Thirty workers from the petroleum refinery and 30 age-matched controls (mean age) were recruited. Visual functions and occupational exposure levels were assessed among both the groups. Visual acuity, contrast sensitivity, color vision, and visual fields were evaluated at the workplace. The biological samples, namely blood and urine, were collected at the workplace and transported to the laboratory for analysis...
September 2016: Indian Journal of Occupational and Environmental Medicine
https://www.readbyqxmd.com/read/28431637/transcranial-color-coded-sonography-of-vertebral-artery-for-diagnosis-of-right-to-left-shunts
#9
Teppei Komatsu, Yuka Terasawa, Ayumi Arai, Kenichi Sakuta, Hidetaka Mitsumura, Yasuyuki Iguchi
BACKGROUND: It is unknown whether contrast transcranial color-coded sonography of vertebral artery monitoring via the foramen magnum window (cTCCS-VA) is useful to detect right-to-left shunt (RLS). We investigated whether cTCCS-VA can be proposed as an alternative to middle cerebral artery monitoring via the temporal bone window (cTCCS-MCA) for RLS detection, as compared with contrast transesophageal echocardiography (cTEE). METHODS: We evaluated 112 patients with ischemic stroke or transient ischemic attack...
May 15, 2017: Journal of the Neurological Sciences
https://www.readbyqxmd.com/read/28411334/normative-values-for-a-tablet-computer-based-application-to-assess-chromatic-contrast-sensitivity
#10
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/28405391/red-fluorescence-of-the-triplefin-tripterygion-delaisi-is-increasingly-visible-against-background-light-with-increasing-depth
#11
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/28355632/cross-modal-attention-influences-auditory-contrast-sensitivity-decreasing-visual-load-improves-auditory-thresholds-for-amplitude-and-frequency-modulated-sounds
#12
Vivian M Ciaramitaro, Hiu Mei Chow, Luke G Eglington
We used a cross-modal dual task to examine how changing visual-task demands influenced auditory processing, namely auditory thresholds for amplitude- and frequency-modulated sounds. Observers had to attend to two consecutive intervals of sounds and report which interval contained the auditory stimulus that was modulated in amplitude (Experiment 1) or frequency (Experiment 2). During auditory-stimulus presentation, observers simultaneously attended to a rapid sequential visual presentation-two consecutive intervals of streams of visual letters-and had to report which interval contained a particular color (low load, demanding less attentional resources) or, in separate blocks of trials, which interval contained more of a target letter (high load, demanding more attentional resources)...
March 1, 2017: Journal of Vision
https://www.readbyqxmd.com/read/28322387/color-resolution-improvement-of-the-dark-field-microscopy-imaging-of-single-light-scattering-plasmonic-nanoprobes-for-microrna-visual-detection
#13
Jun Zhou, Peng Fei Gao, Hong Zhi Zhang, Gang Lei, Lin Ling Zheng, Hui Liu, Cheng Zhi Huang
Imaging of light scattering plasmonic nanoparticles (PNPs) with the aid of the dark-field microscopy imaging (iDFM) technique has attracted wide attention owing to its high signal-to-noise ratio, but to improve the color resolution and contrast of dark-field microscopy (DFM) images of single light scattering PNPs in a small spectral variation environment is still a challenge. In this study, a new color analytical method for resolving the resolution and contrast in DFM images has been developed and further applied for colorimetric analysis using the digital image processing technique...
March 21, 2017: Nanoscale
https://www.readbyqxmd.com/read/28282060/visual-dysfunction-and-its-correlation-with-retinal-changes-in-patients-with-alzheimer-s-disease
#14
V Polo, M J Rodrigo, E Garcia-Martin, S Otin, J M Larrosa, M I Fuertes, M P Bambo, L E Pablo, M Satue
AimTo evaluate visual dysfunction and its correlation with structural changes in the retina in patients with Alzheimer's disease (AD).MethodsPatients with AD (n=24) and controls (n=24) underwent evaluation of visual acuity (VA), color vision (using the Farnsworth and L'Anthony desaturated (D) 15 color tests), and contrast sensitivity vision (CSV; using the Pelli-Robson chart and CSV-1000E test) to measure visual dysfunction. Structural measurements of the retinal nerve fiber layer (RNFL) and macular thickness were obtained using spectral domain-optical coherence tomography (SD-OCT)...
March 10, 2017: Eye
https://www.readbyqxmd.com/read/28273721/neurochemical-responses-to-chromatic-and-achromatic-stimuli-in-the-human-visual-cortex
#15
Petr Bednařík, Ivan Tkáč, Federico Giove, Lynn E Eberly, Dinesh K Deelchand, Felipe R Barreto, Silvia Mangia
In the present study, we aimed at determining the metabolic responses of the human visual cortex during the presentation of chromatic and achromatic stimuli, known to preferentially activate two separate clusters of neuronal populations (called "blobs" and "interblobs") with distinct sensitivity to color or luminance features. Since blobs and interblobs have different cytochrome-oxidase (COX) content and micro-vascularization level (i.e., different capacities for glucose oxidation), different functional metabolic responses during chromatic vs...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28237426/the-role-of-the-human-visual-cortex-in-assessment-of-the-long-term-durability-of-retinal-gene-therapy-in-follow-on-rpe65-clinical-trial-patients
#16
Manzar Ashtari, Elena S Nikonova, Kathleen A Marshall, Gloria J Young, Puya Aravand, Wei Pan, Gui-Shuang Ying, Aimee E Willett, Mani Mahmoudian, Albert M Maguire, Jean Bennett
PURPOSE: Gene therapy (GT) has offered immense hope to individuals who are visually impaired because of RPE65 mutations. Although GT has shown great success in clinical trials enrolling these individuals, evidence for stability and durability of this treatment over time is still unknown. Herein we explored the value of functional magnetic resonance imaging (fMRI) as an objective measure to assess independently the longevity of retinal GT. DESIGN: Individuals with RPE65 mutations who underwent GT in their worse-seeing eye in a phase 1 clinical trial received a second subretinal injection in their contralateral eye in a follow-on clinical trial...
February 22, 2017: Ophthalmology
https://www.readbyqxmd.com/read/28214221/relationship-between-the-melanocortin-1-receptor-mc1r-variant-r306ter-and-physiological-responses-to-mechanical-or-thermal-stimuli-in-labrador-retriever-dogs
#17
Tania E Perez, Katrina L Mealey, Neal S Burke, Tamara L Grubb, Michael H Court, Stephen A Greene
OBJECTIVE: Variants in the MC1R gene have been associated with red hair color and sensitivity to pain in humans. The study objective was to determine if a relationship exists between MC1R genotype and physiological thermal or mechanical nociceptive thresholds in Labrador Retriever dogs. STUDY DESIGN: Prospective experimental study. ANIMALS: Thirty-four Labrador Retriever dogs were included in the study following public requests for volunteers...
January 11, 2017: Veterinary Anaesthesia and Analgesia
https://www.readbyqxmd.com/read/28208185/evaluation-of-progressive-visual-dysfunction-and-retinal-degeneration-in-patients-with-parkinson-s-disease
#18
Maria Satue, Maria J Rodrigo, Javier Obis, Elisa Vilades, Hector Gracia, Sofia Otin, Maria I Fuertes, Raquel Alarcia, Jose A Crespo, Vicente Polo, Jose M Larrosa, Luis E Pablo, Elena Garcia-Martin
Purpose: To quantify changes in visual function parameters and in the retinal nerve fiber layer and macular thickness over a 5-year period in patients with Parkinson's disease (PD). Methods: Thirty patients with PD and 30 healthy subjects underwent a complete ophthalmic evaluation, including assessment of visual acuity, contrast sensitivity vision, color vision, and retinal evaluation with spectral-domain optical coherence tomography (SD-OCT). All subjects were reevaluated after 5 years to quantify changes in visual function parameters, the retinal nerve fiber layer, and macular thickness...
February 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28180194/prospective-evaluation-of-quasistatic-ultrasound-elastography-use-compared-with-baseline-us-for-parotid-gland-lesions-preliminary-results-of-elasticity-contrast-index-eci-evaluation
#19
Vito Cantisani, Emanuele David, Armando De Virgilio, Paul S Sidhu, Hektor Grazhdani, Antonio Greco, Marco De Vincentiis, Alessandro Corsi, Flaminia De Cristofaro, Luca Brunese, Fabrizio Calliada, Alfredo Blandino, Mario Tombolini, Giorgio Ascenti, Roberto Stramare, Marcello Caratozzolo, Ferdinando D'Ambrosio
AIMS: To assess the diagnostic value of elasticity contrast index (ECI) elastography, in comparison with conventional ultrasound for the differentiation of benign and malignant parotid lesions. MATERIAL AND METHODS: Sixty-three consecutive patients with parotid gland tumors, treated surgically at a single tertiary center were enrolled. Ultrasound evaluation consisted of B-mode, color-Doppler and quasistatic ultrasound elastography (USE), conducted with the ECI technique...
January 31, 2017: Medical Ultrasonography
https://www.readbyqxmd.com/read/28159970/the-clinical-phenotype-of-cnga3-related-achromatopsia-pretreatment-characterization-in-preparation-of-a-gene-replacement-therapy-trial
#20
Ditta Zobor, Annette Werner, Franco Stanzial, Francesco Benedicenti, Günther Rudolph, Ulrich Kellner, Christian Hamel, Sten Andréasson, Gergely Zobor, Torsten Strasser, Bernd Wissinger, Susanne Kohl, Eberhart Zrenner
Purpose: The purpose of this study was to clinically characterize patients with CNGA3-linked achromatopsia (CNGA3-ACHM) in preparation of a gene therapy trial. Methods: Thirty-six patients (age 7-56 years) with complete (cACHM) or incomplete (iACHM) CNGA3-ACHM were examined, including detailed psychophysical tests, extended electrophysiology, and assessment of morphology by fundus autofluorescence and spectral-domain optical coherence tomography (SD-OCT). Results: Mean best-corrected visual acuity was 0...
February 1, 2017: Investigative Ophthalmology & Visual Science
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