Adjustment to reward reduction (but no negative contrast) in rats 11, 14, and 16 days of age.

1980 ◽  
Vol 94 (3) ◽  
pp. 446-458 ◽  
Author(s):  
Mark Stanton ◽  
Abram Amsel
Keyword(s):  
Negative Contrast ◽  
Reward Reduction

Another Failure to Obtain Negative Incentive Contrast following Reductions in Sucrose Reward

1973 ◽  
Vol 33 (3) ◽  
pp. 801-802 ◽  
Author(s):  
W. Barnes ◽  
Tom N. Tombaugh
Keyword(s):  
Negative Contrast ◽  
Solid Food ◽  
Contrast Effects ◽  
Discrete Trial ◽  
Sucrose Reward ◽  
Incentive Contrast ◽  
Reward Reduction

The effects of reductions in volume only, concentration only, and volume plus concentration of sucrose rewards were studied in a discrete-trial (retractable bar) situation. There was no evidence of abrupt behavioral decrements or negative contrast effects associated with any type of reward reduction. The present results are in opposition to those obtained following variations in solid food rewards. These findings suggest that the effects of sucrose and solid food manipulations require different theoretical interpretations.

Bubble study as a medium of contrast for computerized tomography coronary angiography. (Preprint)

2020 ◽  
Author(s):  
Vijay Shah ◽  
Justyn Huang
Keyword(s):  
Pulmonary Artery ◽  
Diagnostic Yield ◽  
Negative Contrast ◽  
Hounsfield Unit ◽  
Hounsfield Units ◽  
Computed Tomographic ◽  
Invasive Test ◽  
Clinical Difference ◽  
Contrast Ct ◽  
Scan Protocol

BACKGROUND Computed tomographic coronary angiogram (CTCA) is a non-invasive test with a negative predictive value of nearly 100% for the detection of coronary artery study. While diagnostic yield of a dedicated CTCA with bubble contrast is not yet evaluated OBJECTIVE To assess the diagnostic performance of injected bubble contrast and ability to measure difference in hounsfield units and use it as a "negative contrast" in computed tomographic METHODS This is a single center, single patient study. Baseline acquisition of a non-contrast CT scan was acquired to get hounsfield unit count in the aorta and pulmonary artery- (Calcium scan protocol) 1.4 mGy (19.5 mGy/cm). Secondly, Echo contrasts (Definity) - 5mls was injected and an echocardiogram confirmed filling in the aortic region. Finally, bubble contrast (1ml air, 8mls water and 1mls blood was drawn up and agitated through a 3 way tap) - was injected, a timing run was initiated to calculate for the bubbles to opacity the pulmonary artery. The same scan protocol was used– 1.4 mGy (19.5 mGy/cm). RESULTS Hounsfield units’ difference in the aorta and pulmonary artery from baseline compared to echo contrast and bubble contrast were not significant. CONCLUSIONS We believe this is the first ever recorded case to use bubbles as CT contrast. While results were not significant, secondary to small volume of bubbles injected. Further research needs to be implemented to assess clinical difference with amount of bubbles and volume required. CLINICALTRIAL Single centre study

scholarly journals Positive Contrast Imaging of SPIO Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Chenghong Lin ◽  
Shuhui Cai ◽  
Jianghua Feng
Keyword(s):  
Negative Contrast ◽  
Superparamagnetic Iron Oxide ◽  
Positive Contrast ◽  
Disease Diagnosis ◽  
Cell Labeling ◽  
Contrast Imaging ◽  
Advantages And Disadvantages ◽  
Tissue Interface ◽  
Dark Signal ◽  
Ideal Method

It is advantageous to achieve positive contrast images instead of negative contrast images in superparamagnetic iron-oxide (SPIO) nanoparticles-based MR imaging in order to distinguish the signal surrounding SPIO nanoparticles from the dark signal due to local field inhomogeneity and the artifacts due to tissue interface and background noise, eliminate the inherent defects in the traditional MRI such as partial-volume effects and large void volume for reliable visualization, and increase contrast-to-noise ratio. Many methods generating positive signal with SPIO nanoparticles have been developed in the last decade. This paper provides an overview of current visualization methods and states their advantages and disadvantages. In practice, these techniques have been widely applied to cell labeling and disease diagnosis and monitoring. However, there is still a need for an ideal method to achieve both accuracy and sensitivity.

Effect of septal lesions on retention of negative contrast

1973 ◽  
Vol 11 (5) ◽  
pp. 625-631 ◽  
Author(s):  
Charles F. Flaherty ◽  
Salvatore Capobianco ◽  
Leonard W. Hamilton
Keyword(s):  
Negative Contrast ◽  
Septal Lesions

Effects of amisulpride on consummatory negative contrast

2002 ◽  
Vol 13 (8) ◽  
pp. 659-662 ◽  
Author(s):  
R.F. Genn ◽  
A.M. Barr ◽  
A.G. Phillips
Keyword(s):  
Negative Contrast

Computed Tomography of the Pancreas: Negative Contrast Medium

Radiology ◽  
1978 ◽  
Vol 128 (3) ◽  
pp. 827-828 ◽  
Author(s):  
G. Nicholas Baldwin
Keyword(s):  
Computed Tomography ◽  
Contrast Medium ◽  
Negative Contrast

Evaluation of an operant successive negative contrast task as a method to study affective state in rodents

2012 ◽  
Vol 234 (2) ◽  
pp. 155-160 ◽  
Author(s):  
Emma N. Mitchell ◽  
Hugh M. Marston ◽  
David J. Nutt ◽  
Emma S.J. Robinson
Keyword(s):  
Affective State ◽  
Negative Contrast ◽  
Successive Negative Contrast
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