keyword
MENU ▼
Read by QxMD icon Read
search

Fixation disparity

keyword
https://www.readbyqxmd.com/read/28317909/the-active-side-of-stereopsis-fixation-strategy-and-adaptation-to-natural-environments
#1
Agostino Gibaldi, Andrea Canessa, Silvio P Sabatini
Depth perception in near viewing strongly relies on the interpretation of binocular retinal disparity to obtain stereopsis. Statistical regularities of retinal disparities have been claimed to greatly impact on the neural mechanisms that underlie binocular vision, both to facilitate perceptual decisions and to reduce computational load. In this paper, we designed a novel and unconventional approach in order to assess the role of fixation strategy in conditioning the statistics of retinal disparity. We integrated accurate realistic three-dimensional models of natural scenes with binocular eye movement recording, to obtain accurate ground-truth statistics of retinal disparity experienced by a subject in near viewing...
March 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28245490/gaze-behavior-during-3-d-face-identification-is-depth-cue-invariant
#2
Hassan Akhavein, Reza Farivar
Gaze behavior during scene and object recognition can highlight the relevant information for a task. For example, salience maps-highlighting regions that have heightened luminance, contrast, color, etc. in a scene-can be used to predict gaze targets. Certain tasks, such as face recognition, result in a typical pattern of fixations on high salience features. While local salience of a 2-D feature may contribute to gaze behavior and object recognition, we are perfectly capable of recognizing objects from 3-D depth cues devoid of meaningful 2-D features...
February 1, 2017: Journal of Vision
https://www.readbyqxmd.com/read/28192091/the-influence-of-age-on-adaptation-of-disparity-vergence-and-phoria
#3
Tara L Alvarez, Eun H Kim, Chang Yaramothu, Bérangère Granger-Donetti
A paucity of research exists to investigate whether the normal aging process influences the ability to adapt disparity vergence and phoria. Vergence eye movements and dissociated phoria were recorded from 49 healthy subjects (ages 20-70years) using an objective eye movement tracking system. Four-degree vergence responses were modified using a double-step protocol. Dynamics of vergence were quantified via peak velocity. The phoria adaptation experiment measured the magnitude (net change in phoria level) and rate (magnitude divided by the time constant) of phoria adaption during 5min of sustained fixation on a binocular target (40cm/8...
February 16, 2017: Vision Research
https://www.readbyqxmd.com/read/28135308/individual-objective-and-subjective-fixation-disparity-in-near-vision
#4
Wolfgang Jaschinski
Binocular vision refers to the integration of images in the two eyes for improved visual performance and depth perception. One aspect of binocular vision is the fixation disparity, which is a suboptimal condition in individuals with respect to binocular eye movement control and subsequent neural processing. The objective fixation disparity refers to the vergence angle between the visual axes, which is measured with eye trackers. Subjective fixation disparity is tested with two monocular nonius lines which indicate the physical nonius separation required for perceived alignment...
2017: PloS One
https://www.readbyqxmd.com/read/28100751/decision-related-activity-in-macaque-v2-for-fine-disparity-discrimination-is-not-compatible-with-optimal-linear-readout
#5
Stephane Clery, Bruce G Cumming, Hendrikje Nienborg
Fine judgments of stereoscopic depth rely mainly on relative judgments of depth (relative binocular disparity) between objects, rather than judgments of the distance to where the eyes are fixating (absolute disparity). In macaques, visual area V2 is the earliest site in the visual processing hierarchy for which neurons selective for relative disparity have been observed (Thomas et al., 2002). Here, we found that, in macaques trained to perform a fine disparity discrimination task, disparity-selective neurons in V2 were highly selective for the task, and their activity correlated with the animals' perceptual decisions (unexplained by the stimulus)...
January 18, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28094189/medicaid-payer-status-is-linked-to-increased-rates-of-complications-after-treatment-of-proximal-humerus-fractures
#6
Vani J Sabesan, Graysen Petersen-Fitts, Daniel Lombardo, Daniel Briggs, James Whaley
BACKGROUND: Low socioeconomic status and Medicaid insurance as a primary payer have been associated with major disparities in resource utilization and risk-adjusted outcomes for patients undergoing total joint arthroplasty. With the expansion of Medicaid through the Affordable Care Act in 2014, examination of these disparities has become increasingly relevant for the treatment of proximal humerus fracture (PHF). METHODS: The Healthcare Cost and Utilization Project Nationwide Inpatient Sample database was used to identify patients who were treated for PHF from 2002 to 2012...
January 13, 2017: Journal of Shoulder and Elbow Surgery
https://www.readbyqxmd.com/read/28002220/postoperative-computed-tomography-for-articular-fractures-a-systematic-review
#7
Samantha Stott, Zsolt J Balogh
OBJECTIVES: To determine the current published patterns of computed tomography (CT) use postoperatively in peri-articular fractures and identify those populations whereby postoperative CT changes management or results in better clinical outcomes. DATA SOURCES: Systematic review of MEDLINE and Cochrane using a combination of key words, including fracture fixation, fracture healing, and computed tomography. The final update search was performed on May 20, 2015. The search was limited to English language publications of human studies from the past 20 years...
January 2017: Journal of Orthopaedic Trauma
https://www.readbyqxmd.com/read/27943121/the-effects-of-the-binocular-disparity-differences-between-targets-and-maskers-on-visual-search
#8
Ya-Yue Gao, Bruce Schneider, Liang Li
A visual search for targets is facilitated when the target objects are on a different depth plane than other masking objects cluttering the scene. The ability of observers to determine whether one of four letters presented stereoscopically at four symmetrically located positions on the fixation plane differed from the other three was assessed when the target letters were masked by other randomly positioned and oriented letters appearing on the same depth plane as the target letters, or in front, or behind it...
December 9, 2016: Attention, Perception & Psychophysics
https://www.readbyqxmd.com/read/27927698/decision-related-activity-in-macaque-v2-for-fine-disparity-discrimination-is-not-compatible-with-optimal-linear-read-out
#9
Stephane Clery, Bruce G Cumming, Hendrikje Nienborg
Fine judgments of stereoscopic depth rely mainly on relative judgments of depth (relative binocular disparity) between objects, rather than judgments of the distance to where the eyes are fixating (absolute disparity). In macaques, visual area V2 is the earliest site in the visual processing hierarchy for which neurons selective for relative disparity have been observed (Thomas et al, 2002). Here, we found that in macaques trained to perform a fine disparity discrimination task, disparity selective neurons in V2 were highly selective for the task, and their activity correlated with the animals' perceptual decisions (unexplained by the stimulus)...
December 7, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27776360/motion-induced-position-shift-in-stereoscopic-and-dichoptic-viewing
#10
Rumi Hisakata, Daisuke Hayashi, Ikuya Murakami
The static envelope of a Gabor patch with a moving sinusoidal carrier appears shifted in the direction of the carrier motion (De Valois & De Valois, 1991). This phenomenon is called motion-induced position shift. Although several motion-processing stages, ranging from low- to high-level processes, may contribute to position estimation, it is unknown whether a binocular matching stage or an even earlier stage exerts an influence. To elucidate this matter, we investigated the disparity tuning of this illusion by manipulating the binocular disparities of the carrier and the envelope...
October 1, 2016: Journal of Vision
https://www.readbyqxmd.com/read/27761718/gene-migration-for-re-emerging-amebiasis-in-iran-s-northwest-iraq-borders-a-microevolutionary-scale-for-reflecting-epidemiological-drift-of-entamoeba-histolytica-metapopulations
#11
Asad Mohammadzadeh, Adel Spotin, Mahmoud Mahami-Oskouei, Ali Haghighi, Nozhat Zebardast, Kobra Kohansal
In the microevolutionary scales of Entamoeba isolates, the gene migration shows how Entamoeba spp. has epidemiologically drifted among border countries. Five hundred fecal samples were taken from patients suffering gastrointestinal disorders, abdominal pain, and diarrhea at Saggez, northwest Iran located within the border Iraq country. Following parasitological techniques, DNA samples were extracted and amplified by polymerase chain reaction (PCR) of 18S rRNA region to identify Entamoeba infections. To distinguish the Entamoeba spp...
January 2017: Parasitology Research
https://www.readbyqxmd.com/read/27756738/trials-based-on-specific-fracture-configuration-and-surgical-procedures-likely-to-be-more-relevant-for-decision-making-in-the-management-of-fractures-of-the-proximal-humerus-findings-of-a-meta-analysis
#12
S Sabharwal, N K Patel, D Griffiths, T Athanasiou, C M Gupte, P Reilly
OBJECTIVES: The objective of this study was to perform a meta-analysis of all randomised controlled trials (RCTs) comparing surgical and non-surgical management of fractures of the proximal humerus, and to determine whether further analyses based on complexity of fracture, or the type of surgical intervention, produced disparate findings on patient outcomes. METHODS: A systematic review of the literature was performed identifying all RCTs that compared surgical and non-surgical management of fractures of the proximal humerus...
October 2016: Bone & Joint Research
https://www.readbyqxmd.com/read/27647120/comparison-between-medial-rectus-pulley-fixation-and-augmented-recession-in-children-with-convergence-excess-and-variable-angle-infantile-esotropia
#13
Heba M Fouad, Mohamad A Abdelhakim, Ahmed Awadein, Hala Elhilali
PURPOSE: To compare the outcomes of medial rectus (MR) muscle pulley fixation and augmented recession in children with convergence excess esotropia and variable-angle infantile esotropia. METHODS: This was a prospective randomized interventional study in which children with convergence excess esotropia or variable-angle infantile esotropia were randomly allocated to either augmented MR muscle recession (augmented group) or MR muscle pulley posterior fixation (pulley group)...
October 2016: Journal of AAPOS: the Official Publication of the American Association for Pediatric Ophthalmology and Strabismus
https://www.readbyqxmd.com/read/27610465/catalytic-proton-coupled-electron-transfer-from-metal-hydrides-to-titanocene-amides-hydrazides-and-imides-determination-of-thermodynamic-parameters-relevant-to-nitrogen-fixation
#14
Iraklis Pappas, Paul J Chirik
The hydrogenolysis of titanium-nitrogen bonds in a series of bis(cyclopentadienyl) titanium amides, hydrazides and imides by proton coupled electron transfer (PCET) is described. Twelve different N-H bond dissociation free energies (BDFEs) among the various nitrogen-containing ligands were measured or calculated, and effects of metal oxidation state and N-ligand substituent were determined. Two metal hydride complexes, (η(5)-C5Me5)(py-Ph)Rh-H (py-Ph = 2-pyridylphenyl, [Rh]-H) and (η(5)-C5R5)(CO)3Cr-H ([Cr](R)-H, R= H, Me) were evaluated for formal H atom transfer reactivity and were selected due to their relatively weak M-H bond strengths yet ability to activate and cleave molecular hydrogen...
October 3, 2016: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/27559177/neurons-in-striate-cortex-signal-disparity-in-half-matched-random-dot-stereograms
#15
Sid Henriksen, Jenny C A Read, Bruce G Cumming
UNLABELLED: Human stereopsis can operate in dense "cyclopean" images containing no monocular objects. This is believed to depend on the computation of binocular correlation by neurons in primary visual cortex (V1). The observation that humans perceive depth in half-matched random-dot stereograms, although these stimuli have no net correlation, has led to the proposition that human depth perception in these stimuli depends on a distinct "matching" computation possibly performed in extrastriate cortex...
August 24, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27551571/evaluation-of-contemporary-trends-in-femoral-neck-fracture-management-reveals-discrepancies-in-treatment
#16
Julius Bishop, Arthur Yang, Michael Githens, Alex H S Sox
BACKGROUND: Recent evidence supports total hip arthroplasty (THA) as compared to hemiarthroplasty (HA) for the management of displaced femoral neck fractures in a significant subset of elderly patients. The purpose of this study was to examine trends in femoral neck fracture management over the last 12 years. METHODS: Using the National Inpatient Sample database, we identified patients treated for femoral neck fractures between 1998 and 2010 with THA, HA, or internal fixation (IF)...
September 2016: Geriatric Orthopaedic Surgery & Rehabilitation
https://www.readbyqxmd.com/read/27391396/radiographic-feasibility-study-of-cortical-bone-trajectory-and-traditional-pedicle-screw-dual-trajectories
#17
Jeffrey P Mullin, Breanna Perlmutter, Eric Schmidt, Edward Benzel, Michael P Steinmetz
OBJECTIVE In 2009, Santoni and colleagues described a novel technique of posterior instrumentation; the cortical bone trajectory (CBT) was described as a caudocephalad and medial-to-lateral trajectory. Reported indications for CBT fixation include patients with osteoporosis, single-level degenerative disease, or adjacent-segment disease (ASD). In cases of revision surgery, it is technically possible and beneficial to place a traditional pedicle screw and a CBT screw at the same spinal level and side. It remains unclear as to the feasibility of placing both a traditional and a CBT screw at all levels of the lumbar spine and with varying trajectories of the preexisting traditional pedicle screws...
December 2016: Journal of Neurosurgery. Spine
https://www.readbyqxmd.com/read/27248566/the-absolute-disparity-anomaly-and-the-mechanism-of-relative-disparities
#18
Adrien Chopin, Dennis Levi, David Knill, Daphne Bavelier
There has been a long-standing debate about the mechanisms underlying the perception of stereoscopic depth and the computation of the relative disparities that it relies on. Relative disparities between visual objects could be computed in two ways: (a) using the difference in the object's absolute disparities (Hypothesis 1) or (b) using relative disparities based on the differences in the monocular separations between objects (Hypothesis 2). To differentiate between these hypotheses, we measured stereoscopic discrimination thresholds for lines with different absolute and relative disparities...
June 1, 2016: Journal of Vision
https://www.readbyqxmd.com/read/27185662/-electronic-eikonometer-measurement-tests-displayed-on-stereoscopic-screen
#19
C Bourdy, Y James
We propose the presentation on a stereoscopic screen of the electronic eikonometer tests intended for analysis and measurement of perceptual effects of binocular disparity. These tests, so-called "built-in magnification tests" are constructed according to the same principle as those of preceding eikonometers (disparity variation parameters being included in each test presentation, which allows, for test observation and measurements during the examination, the removing of any intermediate optical system). The images of these tests are presented separately to each eye, according to active or passive stereoscopic screen technology: (1) Ogle Spatial Test to measure aniseikonia; (2) Fixation Disparity test: binocular nonius; (3) retinal correspondence test evaluated by nonius horopter; (4) stereoscopic test using Julesz' random-dot stereograms (RDS)...
May 2016: Journal Français D'ophtalmologie
https://www.readbyqxmd.com/read/27177815/analysis-of-formalin-fixed-paraffin-embedded-ffpe-tissue-via-proteomic-techniques-and-misconceptions-of-antigen-retrieval
#20
Matthew B O'Rourke, Matthew P Padula
Since emerging in the late 19(th) century, formaldehyde fixation has become a standard method for preservation of tissues from clinical samples. The advantage of formaldehyde fixation is that fixed tissues can be stored at room temperature for decades without concern for degradation. This has led to the generation of huge tissue banks containing thousands of clinically significant samples. Here we review techniques for proteomic analysis of formalin-fixed, paraffin-embedded (FFPE) tissue samples with a specific focus on the methods used to extract and break formaldehyde crosslinks...
2016: BioTechniques
keyword
keyword
75594
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"