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Color contrast sensitivity

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https://www.readbyqxmd.com/read/29434750/comparative-analysis-of-3d-time-resolved-contrast-enhanced-magnetic-resonance-angiography-color-doppler-ultrasound-and-digital-subtraction-angiography-in-symptomatic-carotid-stenosis
#1
Hongkai Cui, Ruifang Yan, Zhansheng Zhai, Jipeng Ren, Zheng Li, Qiang Li, Shouying Wang
The present study aimed to compare the diagnostic value of contrast-enhanced magnetic resonance angiography (CE MRA) with 3D time-resolved imaging of contrast kinetics, color Doppler ultrasound (CDUS) and digital subtraction angiography (DSA) in extracranial carotid stenosis (CS). A total of 54 patients with symptomatic CS were subjected to CDUS, CE MRA and DSA examination. Results of DSA were defined as the standard, and a total of 216 vessels were examined. In each patient four vessels were examined, namely the bilateral common carotid arteries and the bilateral internal carotid arteries...
February 2018: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/29432854/color-vision-impairments-with-low-level-methylmercury-exposure-of-an-amazonian-population-brazil
#2
Cláudia Feitosa-Santana, Givago da Silva Souza, Esaú Sirius Ventura Pupo, Anderson Raiol Rodrigues, Maria Izabel Tentes Cortes, Dora Fix Ventura
Land exploitation that follows deforestation and mining can result in soil erosion and the release of mercury to the waters of rivers in the Amazon Basin. Inorganic mercury is methylated by bacteria that are present in the environment and it serves as a source of human contamination through fish consumption in the form of methylmercury. Long-term exposure to low-level methylmercury in the riverside populations can lead to nervous system alterations, some of which are visual impairments such as loss of luminance contrast sensitivity, restricted visual fields and color vision defects...
February 9, 2018: Neurotoxicology
https://www.readbyqxmd.com/read/29427914/charge-dynamics-in-aluminum-oxide-thin-film-studied-by-ultrafast-scanning-electron-microscopy
#3
Maurizio Zani, Vittorio Sala, Gabriele Irde, Silvia Maria Pietralunga, Cristian Manzoni, Giulio Cerullo, Guglielmo Lanzani, Alberto Tagliaferri
The excitation dynamics of defects in insulators plays a central role in a variety of fields from Electronics and Photonics to Quantum computing. We report here a time-resolved measurement of electron dynamics in 100 nm film of aluminum oxide on silicon by Ultrafast Scanning Electron Microscopy (USEM). In our pump-probe setup, an UV femtosecond laser excitation pulse and a delayed picosecond electron probe pulse are spatially overlapped on the sample, triggering Secondary Electrons (SE) emission to the detector...
January 31, 2018: Ultramicroscopy
https://www.readbyqxmd.com/read/29410694/multiparametric-ultrasound-findings-in-a-patient-with-polyorchidism
#4
Vasileios Rafailidis, Mary Arvaniti, Dimitrios Rafailidis, Dimitrios Sfoungaris
Polyorchidism is a rare condition usually incidentally discovered in young patients investigated with ultrasound for unrelated reasons. It is characterized by the presence of unilateral or, rarely, bilateral supernumerary testes which, depending on the type of polyorchidism, may have their own epididymis and vas deferens. Ultrasound, including B-mode and color Doppler technique, represents the primary imaging modality for the evaluation of scrotal diseases, including the characterization of supernumerary testes, which normally appear identical to the ipsilateral testicular parenchyma on every ultrasonographic technique performed...
August 2017: Ultrasound: Journal of the British Medical Ultrasound Society
https://www.readbyqxmd.com/read/29391774/subthreshold-microsecond-laser-for-proliferative-diabetic-retinopathy-a-randomized-pilot-study
#5
Mahima Jhingan, Abhilash Goud, Hari Kumar Peguda, Mitali Khodani, Jeffrey K Luttrull, Jay Chhablani
Aim: To compare the outcomes of subthreshold microsecond (STM) and continuous-wave laser (CWL) panretinal photocoagulation (PRP). Methods: In this randomized, prospective, pilot study, 20 eyes of 10 subjects with symmetric severe non-proliferative (NPDR) or low-risk proliferative diabetic retinopathy (PDR) were included. Each eye of the subject was randomized into either CWL or STM PRP group. Patients were evaluated at baseline and at months 3, 6, and 9 with color fundus photographs and visual field tests at each visit; however, electroretinography (ERG) was conducted at baseline and at month 9...
2018: Clinical Ophthalmology
https://www.readbyqxmd.com/read/29386518/in-vivo-photoacoustic-monitoring-using-700-nm-region-raman-source-for-targeting-prussian-blue-nanoparticles-in-mouse-tumor-model
#6
Nhat Quang Bui, Soon-Woo Cho, Madhappan Santha Moorthy, Sang Min Park, Zhonglie Piao, Seung Yun Nam, Hyun Wook Kang, Chang-Seok Kim, Junghwan Oh
Photoacoustic imaging (PAI) is a noninvasive imaging tool to visualize optical absorbing contrast agents. Due to high ultrasonic resolution and superior optical sensitivity, PAI can be used to monitor nanoparticle-mediated cancer therapy. The current study synthesized Food and Drug Administration-approved Prussian blue (PB) in the form of nanoparticles (NPs) with the peak absorption at 712 nm for photoacoustically imaging tumor-bearing mouse models. To monitor PB NPs from the background tissue in vivo, we also developed a new 700-nm-region stimulated Raman scattering (SRS) source (pulse energy up to 200 nJ and repetition rate up to 50 kHz) and implemented optical-resolution photoacoustic microscopy (OR-PAM)...
January 31, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29377801/a-sensitive-dynamic-and-active-pixel-vision-sensor-for-color-or-neural-imaging-applications
#7
Diederik Paul Moeys, Federico Corradi, Chenghan Li, Simeon A Bamford, Luca Longinotti, Fabian F Voigt, Stewart Berry, Gemma Taverni, Fritjof Helmchen, Tobi Delbruck
Applications requiring detection of small visual contrast require high sensitivity. Event cameras can provide higher dynamic range (DR) and reduce data rate and latency, but most existing event cameras have limited sensitivity. This paper presents the results of a 180-nm Towerjazz CIS process vision sensor called SDAVIS192. It outputs temporal contrast dynamic vision sensor (DVS) events and conventional active pixel sensor frames. The SDAVIS192 improves on previous DAVIS sensors with higher sensitivity for temporal contrast...
February 2018: IEEE Transactions on Biomedical Circuits and Systems
https://www.readbyqxmd.com/read/29319502/mouse-color-and-wavelength-specific-luminance-contrast-sensitivity-are-non-uniform-across-visual-space
#8
Daniel J Denman, Jennifer A Luviano, Douglas R Ollerenshaw, Sissy Cross, Derric Williams, Michael A Buice, Shawn R Olsen, R Clay Reid
Mammalian visual behaviors, as well as responses in the neural systems underlying these behaviors, are driven by luminance and color contrast. With constantly improving tools for measuring activity in cell-type-specific populations in the mouse during visual behavior, it is important to define the extent of luminance and color information that is behaviorally accessible to the mouse. A non-uniform distribution of cone opsins in the mouse retina potentially complicates both luminance and color sensitivity; opposing gradients of short (UV-shifted) and middle (blue/green) cone opsins suggest that color discrimination and wavelength-specific luminance contrast sensitivity may differ with retinotopic location...
January 10, 2018: ELife
https://www.readbyqxmd.com/read/29228925/daily-activity-patterns-influence-retinal-morphology-signatures-of-selection-and-spectral-tuning-of-opsin-genes-in-colubrid-snakes
#9
E Hauzman, D M O Bonci, E Y Suárez-Villota, M Neitz, D F Ventura
BACKGROUND: Morphological divergences of snake retinal structure point to complex evolutionary processes and adaptations. The Colubridae family has a remarkable variety of retinal structure that can range from all-cone and all-rod to duplex (cone/rod) retinas. To explore whether nocturnal versus diurnal activity is responsible for constraints on molecular evolution and plays a role in visual opsin spectral tuning of colubrids, we carried out molecular evolution analyses of the visual opsin genes LWS, RH1, and SWS1 from 17 species and performed morphological analyses...
December 11, 2017: BMC Evolutionary Biology
https://www.readbyqxmd.com/read/29193461/site-specific-gene-expression-analysis-from-archived-human-intestine-samples-combining-laser-capture-microdissection-and-multiplexed-color-coded-probes
#10
A Braun, C Martinez, S Schmitteckert, R Röth, F Lasitschka, B Niesler
BACKGROUND: Alterations of site-specific gene expression profiles in disease-relevant networks within the different layers of the intestinal wall may contribute to the onset and clinical course of gastrointestinal disorders. To date, no systematic analysis has assessed and compared sub-regional gene expression patterns in all distinct layers of the gut using fresh frozen human samples. Our aim was to establish an optimized protocol for site-specific RNA isolation in order to achieve maximum RNA quality and amount for subsequent gene expression analysis combining laser-capture microdissection (LCM) with a probe-based technology, the NanoString nCounter Analysis system...
November 28, 2017: Neurogastroenterology and Motility: the Official Journal of the European Gastrointestinal Motility Society
https://www.readbyqxmd.com/read/29176841/salient-object-segmentation-based-on-active-contouring
#11
Xin Xia, Tao Lin, Zhi Chen, Hongyan Xu
Traditional saliency detection algorithms lack object semantic character, and the segmentation algorithms cannot highlight the saliency of the segmentation regions. In order to compensate for the defects of these two algorithms, the salient object segmentation model, which is a novel combination of two algorithms, is established in this paper. With the help of a priori knowledge of image boundary background traits, the K-means++ algorithm is used to cluster the pixels for each region; in line with the sensitivity of the human eye to color and with its attention mechanism, the joint probability distribution of the regional contrast ratio and spatial saliency is established...
2017: PloS One
https://www.readbyqxmd.com/read/29155081/population-receptive-field-prf-measurements-of-chromatic-responses-in-human-visual-cortex-using-fmri
#12
Lauren E Welbourne, Antony B Morland, Alex R Wade
The spatial sensitivity of the human visual system depends on stimulus color: achromatic gratings can be resolved at relatively high spatial frequencies while sensitivity to isoluminant color contrast tends to be more low-pass. Models of early spatial vision often assume that the receptive field size of pattern-sensitive neurons is correlated with their spatial frequency sensitivity - larger receptive fields are typically associated with lower optimal spatial frequency. A strong prediction of this model is that neurons coding isoluminant chromatic patterns should have, on average, a larger receptive field size than neurons sensitive to achromatic patterns...
November 14, 2017: NeuroImage
https://www.readbyqxmd.com/read/29137569/the-neuro-ophthalmological-effects-related-to-long-term-occupational-exposure-to-organic-solvents-in-painters
#13
Heba Khodary Allam, Shaimaa Soliman, Tamer Wasfy, Ahmed Ghoneim, Yasser Serag, Grace Sembajwe
PURPOSE: Organic solvents are widely used in many industries, and usually, exposure occurs with mixtures of solvents. Organic solvent mixtures are known for their ability to affect tissues of high lipid content including the myelin sheath in the nervous system. The purpose of this work was to study the evidence that long-term (more than 10 years) exposure to organic solvent mixtures among painters can induce neuro-ophthalmological effects on the function of retinal ganglion cells and the optic tract...
January 1, 2017: Toxicology and Industrial Health
https://www.readbyqxmd.com/read/29133170/hydronephrosis-and-crossing-vessels-in-children-optimization-of-diagnostic-therapeutic-pathway-and-analysis-of-color-doppler-ultrasound-and-magnetic-resonance-urography-diagnostic-accuracy
#14
M C Y Wong, G Piaggio, M B Damasio, C Molinelli, S M Ferretti, A Pistorio, G Ghiggeri, M L Degl'Innocenti, A Canepa, V Incarbone, G Mattioli
INTRODUCTION: Ureteropelvic junction obstruction (UPJO) is one of the most frequent urological diseases affecting the pediatric population. It can be due to both intrinsic stenosis of the junction and extrinsic causes such as the presence of crossing vessels (CVs), which can be detected by color Doppler ultrasound (CD-US). Magnetic resonance urography (MRU) is a good alternative, but sedation and infusion of a contrast agent are required. OBJECTIVE: The aim of this study was to analyze the diagnostic accuracy of CD-US and MRU in visualizing CVs in pediatric hydronephrosis, in order to decide the correct diagnostic pathway in the pre-operative phase...
October 27, 2017: Journal of Pediatric Urology
https://www.readbyqxmd.com/read/29119649/prospective-multimodal-imaging-assessment-of-locally-advanced-cervical-cancer-patients-administered-by-chemoradiation-followed-by-radical-surgery-the-price-prospective-imaging-of-cervical-cancer-and-neoadjuvant-treatment-study-2-the-role-of-ultrasound-after
#15
Antonia Carla Testa, Francesca Moro, Tina Pasciuto, Maria Cristina Moruzzi, Alessia Di Legge, Gilda Fuoco, Rosa Autorino, Angela Collarino, Benedetta Gui, Gian Franco Zannoni, Antonietta Gambacorta, Maura Miccò, Vittoria Rufini, Giovanni Scambia, Gabriella Ferrandina
OBJECTIVE: To determine the diagnostic performance of two-dimensional ultrasound parameters, three-dimensional power Doppler and intravenous contrast enhanced indices in detecting residual disease in locally advanced cervical cancer patients triaged to neoadjuvant treatment followed by radical surgery. METHODS: Between October 2010 and June 2014, 108 women with histologically documented cervical cancer and FIGO stage IB2-IVA were screened and 88 of them were included in the final analysis...
November 8, 2017: Ultrasound in Obstetrics & Gynecology
https://www.readbyqxmd.com/read/29049228/the-efficiency-of-sonography-in-diagnosing-volvulus-in-neonates-with-suspected-intestinal-malrotation
#16
Wenhua Zhang, Hongjun Sun, Fangqiong Luo
This study is to prospectively evaluate the efficiency of sonography for volvulus diagnosis in neonates with clinically suspected intestinal malrotation.A total of 83 patients with suspected intestinal malrotation who underwent detailed abdominal sonography and upper gastrointestinal contrast study were included. Malrotation was characterized by inversion of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in sonographic examination. The "whirlpool sign" of Color Doppler Sonography was recognized as a characteristic for malrotation with volvulus...
October 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/29033863/the-peaceful-co-existence-of-input-frequency-and-structural-intervention-effects-on-the-comprehension-of-complex-sentences-in-german-speaking-children
#17
Flavia Adani, Maja Stegenwallner-Schütz, Talea Niesel
The predictions of two contrasting approaches to the acquisition of transitive relative clauses were tested within the same groups of German-speaking participants aged from 3 to 5 years old. The input frequency approach predicts that object relative clauses with inanimate heads (e.g., the pullover that the man is scratching) are comprehended earlier and more accurately than those with an animate head (e.g., the man that the boy is scratching). In contrast, the structural intervention approach predicts that object relative clauses with two full NP arguments mismatching in number (e...
2017: Frontiers in Psychology
https://www.readbyqxmd.com/read/28992194/a-novel-display-system-reveals-anisotropic-polarization-perception-in-the-motion-vision-of-the-butterfly-papilio-xuthus
#18
Finlay J Stewart, Michiyo Kinoshita, Kentaro Arikawa
While the linear polarization of light is virtually invisible to humans, many invertebrates' eyes can detect it. How this information is processed in the nervous system, and what behavioral function it serves, are in many cases unclear. One reason for this is the technical difficulty involved in presenting images or video containing polarization contrast, particularly if intensity and/or color contrast is also required. In this primarily methods-focused article, we present a novel technique based on projecting video through a synchronously rotating linear polarizer...
November 1, 2017: Integrative and Comparative Biology
https://www.readbyqxmd.com/read/28984142/visual-inspection-of-mr-relative-cerebral-blood-volume-maps-has-limited-value-for-distinguishing-progression-from-pseudoprogression-in-glioblastoma-multiforme-patients
#19
Melissa Kerkhof, Pauline L Tans, Rogier E Hagenbeek, Geert J Lycklama À Nijeholt, Finn K Holla, Tjeerd J Postma, Chiara S Straathof, Linda Dirven, Martin Jb Taphoorn, Maaike J Vos
AIM: We examined whether visual interpretation of relative cerebral blood volume (rCBV) color maps made with dynamic susceptibility-weighted perfusion MRI can reliably distinguish progressive disease (PD) from pseudoprogression (PsPD) in glioblastoma patients during treatment with temozolomide chemoradiation. MATERIALS & METHODS: Magnetic resonance (MR) perfusion-weighted images were evaluated based on visual inspection of rCBV maps. Sensitivity and specificity were calculated to assess if rCBV can reliably differentiate between PD and PsPD, during standard chemoradiation therapy...
October 6, 2017: CNS Oncology
https://www.readbyqxmd.com/read/28983674/contrast-enhanced-ultrasound-ceus-of-the-abdominal-vasculature
#20
REVIEW
Vasileios Rafailidis, Cheng Fang, Gibran T Yusuf, Dean Y Huang, Paul S Sidhu
Vascular diseases account for a significant proportion of abdominal pathology and represent a common referral source for abdominal ultrasonographic examinations. B-mode, color Doppler, and spectral Doppler analyses are well-established in the evaluation of abdominal blood vessels although they may occasionally be limited by lower sensitivity for slow flow visualization or the deeper location of abdominal vascular structures. The introduction of microbubbles as ultrasonographic contrast agents has rendered contrast-enhanced ultrasound (CEUS), a valuable complementary ultrasonographic technique, which is capable of addressing clinically significant problems and guiding patient management...
October 5, 2017: Abdominal Radiology
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