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Color contrast sensitivity

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https://www.readbyqxmd.com/read/29904788/spatio-chromatic-sensitivity-explained-by-post-receptoral-contrast
#1
Marcel Lucassen, Marc Lambooij, Dragan Sekulovski, Ingrid Vogels
We measured and modeled visibility thresholds of spatial chromatic sine-wave gratings at isoluminance. In two experiments we manipulated the base color, direction of chromatic modulation, spatial frequency, the number of cycles in the grating, and grating orientation. In Experiment 1 (18 participants) we studied four chromatic modulation directions around three base colors, for spatial frequencies 0.15-5 cycles/deg. Results show that the location, size and orientation of fitted ellipses through the observer-averaged thresholds varied with spatial frequency and base color...
May 1, 2018: Journal of Vision
https://www.readbyqxmd.com/read/29889960/optimizing-tactical-medical-performance-the-effect-of-light-hue-on-vision-testing
#2
J Preston Van Buren, Jeffrey Wake, Jared McLaughlin, Anthony J LaPorta, Robert W Enzenauer, Christopher J Calvano
BACKGROUND: Red and blue are the historical tactical lighting hues of choice to ensure light discipline and to preserve dark adaptation. As yet, no scientifically ideal hue for use in Special Operations medicine has been identified. We propose red/green polychromatic light as a superior choice that preserves visual function for tactical medical tasks in austere settings. METHODS: Thirty participants were enrolled in this institutional review board-approved study...
2018: Journal of Special Operations Medicine: a Peer Reviewed Journal for SOF Medical Professionals
https://www.readbyqxmd.com/read/29888061/automated-detection-of-diabetic-retinopathy-using-deep-learning
#3
Carson Lam, Darvin Yi, Margaret Guo, Tony Lindsey
Diabetic retinopathy is a leading cause of blindness among working-age adults. Early detection of this condition is critical for good prognosis. In this paper, we demonstrate the use of convolutional neural networks (CNNs) on color fundus images for the recognition task of diabetic retinopathy staging. Our network models achieved test metric performance comparable to baseline literature results, with validation sensitivity of 95%. We additionally explored multinomial classification models, and demonstrate that errors primarily occur in the misclassification of mild disease as normal due to the CNNs inability to detect subtle disease features...
2018: AMIA Summits on Translational Science Proceedings
https://www.readbyqxmd.com/read/29876784/superb-micro-vascular-imaging-smi-a-doppler-ultrasound-technique-with-potential-to-identify-classify-and-follow-up-endoleaks-in-patients-after-endovascular-aneurysm-repair-evar
#4
Marcin Gabriel, Jolanta Tomczak, Magdalena Snoch-Ziółkiewicz, Łukasz Dzieciuchowicz, Ewa Strauss, Katarzyna Pawlaczyk, Dorota Wojtusik, Grzegorz Oszkinis
PURPOSE: The aim of the study was to assess the effectiveness of Superb Micro-vascular Imaging (SMI) as an alternative to Contrast-Enhanced Ultrasound (CEUS) and Computed Tomography Angiography (CTA) for endoleak detection and classification in patients followed up after endovascular abdominal aortic aneurysm repair (EVAR). MATERIALS AND METHODS: From May 2015 to January 2017, 30 patients underwent post-EVAR follow-up with Color Doppler Ultrasound (CDUS), CEUS, SMI, and CTA examinations...
June 6, 2018: Abdominal Radiology
https://www.readbyqxmd.com/read/29869494/covalent-organic-polymers-for-rapid-fluorescence-imaging-of-latent-fingerprints
#5
Meng Wang, Lin Guo, Dapeng Cao
Rapid, simple and highly sensitive identification of latent fingerprints (LFPs) is an important issue related to national security and recognition of potential crimes. Here, we synthesized a series of covalent organic polymers (COPs) with colorful fluorescence (from blue to green, pale yellow, bright yellow and red), and further investigated its performance for fluorescence imaging of LFPs. Results indicate that the COP materials can be used as fluorescence probes to rapidly visualize the precision substructure of LFPs within 5 s by simply spraying method, and tunable fluorescent color makes the COP probes have a high contrast and low interference for fluorescence imaging of LFPs on different substrates (including glass slides, paper, aluminum foil, plastic, ironware) in different backgrounds...
June 5, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29861297/non-mass-breast-lesions-on-ultrasound-feature-exploration-and-multimode-ultrasonic-diagnosis
#6
Wenyue Zhang, Xiaoyun Xiao, Xiaolin Xu, Ming Liang, Huan Wu, Jingliang Ruan, Baoming Luo
The aim of this study was to analyze the features of non-mass breast lesions (NMLs) on B-mode ultrasound (US), color Doppler US, strain elastography (SE) and contrast-enhanced ultrasound (CEUS) and to develop a multimode ultrasonic method for NML differentiation. Seventy-one NMLs were included in this retrospective study. Binary logistic regression was used to identify the independent risk factors. Pathology results were used as the standard criterion. Microcalcification on US, high stiffness on SE and hyper-enhanced intensity on CEUS were identified as features correlated with malignancy...
May 31, 2018: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/29859199/subretinal-drusenoid-deposits-aka-pseudodrusen
#7
REVIEW
Richard F Spaide, Sotaro Ooto, Christine A Curcio
A distinction between conventional drusen and pseudodrusen was first made in 1990, and more recently knowledge of pseudodrusen, more accurately called subretinal drusenoid deposits (SDD), has expanded. Pseudodrusen have a bluish-white appearance by biomicroscopy and color fundus photography. Using optical coherence tomography, pseudodrusen were found to be accumulations of material internal to the retinal pigment epithelium (RPE) that could extend internally through the ellipsoid zone. These deposits are more commonly seen in older eyes with thinner choroids...
May 30, 2018: Survey of Ophthalmology
https://www.readbyqxmd.com/read/29858125/value-of-contrast-enhanced-ultrasound-in-detecting-competent-and-incompetent-lower-extremity-perforating-veins
#8
Jie Zhang, Ming Xiao, Nan Kang, Changshuai Yan, Jiechang Zhu, Xiangchen Dai
The purpose of this study was to investigate the value of contrast-enhanced ultrasound (CEUS) in the identification of competent and incompetent lower-extremity perforating veins. Patients with chronic venous insufficiency who met the inclusion criteria were enrolled. All patients underwent pre-operative CEUS and color Doppler ultrasound (CDU) and accepted subfascial endoscopic perforator surgery. We compared the numbers of perforator veins identified by CEUS and CDU with the endoscopy result, which was considered the gold standard...
May 29, 2018: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/29843868/ultrasensitive-dna-detection-with-hydrodynamic-separation-of-plasmonic-nanoparticles-and-isothermal-amplification
#9
Mohamed Shehata Draz, Luyao Ma, Xiaonan Lu
Nucleic acid based assays are routinely used to detect diseases and monitor medical treatment. Here, we demonstrated a novel approach for colorimetric DNA detection using plasmonic gold nanoparticles (AuNPs) as hydrodynamic separators coupled with differential centrifugation. This approach relies upon the change in the sedimentation rate of AuNPs when conjugated to DNA amplicons. Isothermal nucleic acid amplification results in the formation of unique DNA amplicons that is large enough to prevent the sedimentation of conjugated AuNPs at a specific centrifugal force...
June 1, 2018: Journal of Biomedical Nanotechnology
https://www.readbyqxmd.com/read/29778549/linked-color-imaging-can-help-gastric-helicobacter-pylori-infection-diagnosis-during-endoscopy
#10
Tsung-Hsing Chen, Chen-Ming Hsu, Hao-Tsai Cheng, Yin-Yi Chu, Ming-Yao Su, Jun-Te Hsu, Ta-Sen Yeh, Chang-Fu Kuo, Cheng-Tang Chiu
BACKGROUND: Esophagogastroduodenoscopy (EGD) is a standard tool for detection of mucosal and submucosal lesions. However, identification of Helicobacter pylori (H. P) infection using EGD alone is limited in accuracy. Linked color imaging (LCI) is a novel tool to capture real-time image with sufficient contrast to observe mucosal microstructure. METHODS: This study aims to evaluate the applicability of LCI in the identification of H. pylori infection. Consecutive 122 patients scheduled for EGD were included...
May 16, 2018: Journal of the Chinese Medical Association: JCMA
https://www.readbyqxmd.com/read/29774751/evaluation-of-articular-cartilage-injury-using-computed-tomography-with-axial-traction-in-the-ankle-joint
#11
Tomoyuki Nakasa, Yasunari Ikuta, Mikiya Sawa, Masahiro Yoshikawa, Yusuke Tsuyuguchi, Yuki Ota, Munekazu Kanemitsu, Nobuo Adachi
BACKGROUND: Although chondral or osteochondral injuries are usually assessed by magnetic resonance imaging, its accuracy can be low, presumably related to the relatively thin cartilage layer and the close apposition of the cartilage of the talus and tibial plafond. We hypothesized that axial traction could provide a contrast between the articular cartilage and joint cavity, and it enabled the simultaneous evaluation of cartilage and subchondral bone. The purpose of this study was to assess the feasibility of using computed tomography (CT) imaging with axial traction for the diagnosis of articular cartilage injuries...
May 1, 2018: Foot & Ankle International
https://www.readbyqxmd.com/read/29773755/expectations-do-not-alter-early-sensory-processing-during-perceptual-decision-making
#12
Nuttida Rungratsameetaweemana, Sirawaj Itthipuripat, Annalisa Salazar, John T Serences
Two factors play an important role in shaping perception: the allocation of selective attention to behaviorally relevant sensory features, and prior expectations about regularities in the environment. Signal detection theory proposes distinct roles of attention and expectation on decision-making such that attention modulates early sensory processing whereas expectation influences the selection and execution of motor responses. Challenging this classic framework, recent studies suggest that expectations about sensory regularities enhance the encoding and accumulation of sensory evidence during decision-making...
May 17, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29755502/functional-conservation-and-divergence-of-soybean-gmstop1-members-in-proton-and-aluminum-tolerance
#13
Weiwei Wu, Yan Lin, Qianqian Chen, Wenting Peng, Junchu Peng, Jiang Tian, Cuiyue Liang, Hong Liao
Proton (H+ ) and aluminum (Al) rhizotoxicity are two major factors limiting crop production in acid soils. Orthologs of the zinc-finger transcription factor, Sensitive To Proton Rhizotoxicity1 (STOP1), have been found to play an essential role in the tolerance to both stresses by regulating the transcription of multiple H+ and Al tolerant genes. In the present study, color three GmSTOP1 homologs were identified in the soybean genome. All three GmSTOP1 exhibited similar properties as reflected by the harboring of four potential zinc finger domains, localizing in the nucleus, and having transactivation activity...
2018: Frontiers in Plant Science
https://www.readbyqxmd.com/read/29753728/retinal-adaptation-to-dim-light-vision-in-spectacled-caimans-caiman-crocodilus-fuscus-analysis-of-retinal-ultrastructure
#14
Anett Karl, Silke Agte, Astrid Zayas-Santiago, Felix N Makarov, Yomarie Rivera, Jan Benedikt, Mike Francke, Andreas Reichenbach, Serguei N Skatchkov, Andreas Bringmann
It has been shown that mammalian retinal glial (Müller) cells act as living optical fibers that guide the light through the retinal tissue to the photoreceptor cells (Agte et al., 2011; Franze et al., 2007). However, for nonmammalian species it is unclear whether Müller cells also improve the transretinal light transmission. Furthermore, for nonmammalian species there is a lack of ultrastructural data of the retinal cells, which, in general, delivers fundamental information of the retinal function, i.e. the vision of the species...
May 10, 2018: Experimental Eye Research
https://www.readbyqxmd.com/read/29744762/functional-and-morphological-assessment-of-ocular-structures-and-follow-up-of-patients-with-early-stage-parkinson-s-disease
#15
Samir Hasanov, Elif Demirkilinc Biler, Ahmet Acarer, Cezmi Akkın, Zafer Colakoglu, Onder Uretmen
PURPOSE: To evaluate and follow-up of functional and morphological changes of the optic nerve and ocular structures prospectively in patients with early-stage Parkinson's disease. MATERIALS AND METHODS: Nineteen patients with a diagnosis of early-stage Parkinson's disease and 19 age-matched healthy controls were included in the study. All participants were examined minimum three times at the intervals of at least 6 month following initial examination. Pattern visually evoked potentials (VEP), contrast sensitivity assessments at photopic conditions, color vision tests with Ishihara cards and full-field visual field tests were performed in addition to measurement of retinal nerve fiber layer (RNFL) thickness of four quadrants (top, bottom, nasal, temporal), central and mean macular thickness and macular volumes...
May 9, 2018: International Ophthalmology
https://www.readbyqxmd.com/read/29723846/diagnostic-value-of-nineteen-different-imaging-methods-for-patients-with-breast-cancer-a-network-meta-analysis
#16
Xiao-Hong Zhang, Can Xiao
BACKGROUND/AIMS: We performed a network meta-analysis (NMA) to investigate and compare the diagnostic value of 19 different imaging methods used for breast cancer (BC). METHODS: Cochrane Library, PubMed and EMBASE were searched to collect the relevant literature from the inception of the study until November 2016. A combination of direct and indirect comparisons was performed using an NMA to evaluate the combined odd ratios (OR) and draw the surface under the cumulative ranking curves (SUCRA) of the diagnostic value of different imaging methods for BC...
April 28, 2018: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/29705653/lrrk2-associated-parkinson-s-disease-patients-have-better-stereopsis-than-idiopathic-parkinson-disease
#17
Liang Sun, Piu Chan
OBJECTIVES: Visual dysfunctions are frequent and have several manifestations in idiopathic Parkinson's disease (PD). However, the characteristics of these complications in LRRK2 (leucine-rich kinase 2)-associated PD patients still lack systematic research. The purpose of this study is to assess visual functions of LRRK2-associated PD patients. PATIENTS AND METHODS: Twenty-five (25) PD patients with LRRK2 R1628P and G2385R variants were included in the study and compared to 28 PD patients without these variants and 28 age-matched healthy controls...
April 22, 2018: Clinical Neurology and Neurosurgery
https://www.readbyqxmd.com/read/29679616/early-detection-of-diabetic-retinopathy
#18
REVIEW
Hamid Safi, Sare Safi, Ali Hafezi-Moghadam, Hamid Ahmadieh
Diabetic retinopathy (DR) is a primary cause of visual impairment worldwide. Diabetes mellitus may be associated with ophthalmoscopically nonvisible neurovascular damage that progresses before the first clinical signs of DR appear. Reduction of the inner neuroretinal layer thickness on macular optical coherence tomography (OCT), reduced contrast sensitivity primarily at low spatial frequencies, abnormal results in color vision and microperimetry tests, and a prolonged implicit time recorded by multifocal electroretinography have been proposed for detection of early functional and nonvisible structural neuroretinal changes...
April 18, 2018: Survey of Ophthalmology
https://www.readbyqxmd.com/read/29673784/visual-texture-agnosia-in-dementia-with-lewy-bodies-and-alzheimer-s-disease
#19
Yuka Oishi, Toru Imamura, Tatsuo Shimomura, Kyoko Suzuki
BACKGROUND: Neuroimaging and some clinical studies have reported that the ventral visual pathway is relevant for visual texture recognition. Although a variety of visual deficits have been reported in patients with Alzheimer's disease (AD) and dementia with Lewy bodies (DLB), visual material identification and texture recognition have not been thoroughly examined. OBJECTIVES: To investigate visual texture recognition in patients with AD and DLB and to clarify the relationship between visual texture recognition and various visuoperceptual functions...
June 2018: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/29670831/predicting-visual-disability-in-glaucoma-with-combinations-of-vision-measures
#20
Stephanie Lin, Aleksandra Mihailovic, Sheila K West, Chris A Johnson, David S Friedman, Xiangrong Kong, Pradeep Y Ramulu
Purpose: We characterized vision in glaucoma using seven visual measures, with the goals of determining the dimensionality of vision, and how many and which visual measures best model activity limitation. Methods: We analyzed cross-sectional data from 150 older adults with glaucoma, collecting seven visual measures: integrated visual field (VF) sensitivity, visual acuity, contrast sensitivity (CS), area under the log CS function, color vision, stereoacuity, and visual acuity with noise...
April 2018: Translational Vision Science & Technology
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