Initial Neighborhood Biases and the Quality of Motion Stimulation Jointly Influence the Rapid Emergence of Direction Preference in Visual Cortex

Vision of newborn infants is limited by immaturities in their visual brain. In adult primates, the transient onset discharges of visual cortical neurons are thought to be intimately involved with capturing the rapid succession of brief images in visual scenes. Here we sought to determine the responsiveness and quality of transient responses in individual neurons of the primary visual cortex (V1) and visual area 2 (V2) of infant monkeys. We show that the transient component of neuronal firing to 640-ms stationary gratings was as robust and as reliable as in adults only 2 wk after birth, whereas the sustained component was more sluggish in infants than in adults. Thus the cortical circuitry supporting onset transient responses is functionally mature near birth, and our findings predict that neonates, known for their “impoverished vision,” are capable of initiating relatively mature fixating eye movements and of performing in detection of simple objects far better than traditionally thought.

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A Transmission Index for Spatial Mechanisms

Journal of Engineering for Industry ◽

10.1115/1.3438195 ◽

1973 ◽

Vol 95 (2) ◽

pp. 589-597 ◽

Cited By ~ 78

Author(s):

G. Sutherland ◽

B. Roth

Keyword(s):

Error Characteristics ◽

General Index ◽

Spatial Mechanisms ◽

Transmission Index ◽

Quality Of Motion ◽

Spatial Linkages

A general index of the quality of motion transmission for spatial mechanisms is developed using the theory of screws. This index is shown to be related to the mechanical error possible in a linkage. A method for synthesizing spatial linkages with desirable motion transmission and mechanical error characteristics is developed and examples are shown for the RGGR linkage.

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New Toothed Belt Matches Various Pulley-Profiles

Volume 6: 8th International Power Transmission and Gearing Conference ◽

10.1115/detc2000/ptg-14410 ◽

2000 ◽

Author(s):

Frank H. Schaefer

Keyword(s):

Sound Intensity ◽

Belt Drive ◽

Special Test ◽

Intensity Measurements ◽

Test Conditions ◽

Toothed Belt ◽

Quality Of Motion ◽

Center Distance ◽

Dynamometer Test

Abstract This paper examines the possibility of a new toothed belt construction to run in various pulley-types. The measurements from a laboratory dynamometer test stand show the belt life under special test conditions by use of HTD-, STPD- and RPP-pulleys, each with an angle of wrap of 180°. In case of locked center distance the increase of torque causes tooth climbing until belt jumping occurs. The pretension was brought into line with the torque each time the torque was increased and the jumping limit torque was determined. From literature it is expected that the results for the behavior of the HTD- and the RPP-pulley are similar. Another parameter to describe the quality of motion is the noise. Here sound power is a very effective descriptor of how noisy an object is. It was determined from sound intensity measurements for HTD- and STPD-pulleys. The ratio of the toothed belt drive used for the noise measurement was 0.63.

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Comparison of the effect of intravenous dexmedetomidine and lignocaine spray instilled into the endotracheal tube on extubation response in patients undergoing spine surgery

Journal of Neuroanaesthesiology and Critical Care ◽

10.4103/2348-0548.190070 ◽

2016 ◽

Vol 03 (03) ◽

pp. 239-244 ◽

Cited By ~ 1

Author(s):

Debojyoti Dutta ◽

Mukesh Godara ◽

Shobha Purohit ◽

Poonam Kalra ◽

Satya Sharma ◽

...

Keyword(s):

Blood Pressure ◽

Endotracheal Tube ◽

Spine Surgery ◽

Spontaneous Respiration ◽

Sedation Level ◽

Before And After ◽

Group D ◽

Rapid Emergence ◽

Better Than

Abstract Background: In spine surgery rapid emergence and extubation with haemodynamic stability is crucial for early neurological examination. Here, we have studied the effect of α2 agonist – dexmedetomidine intravenous (IV) and lignocaine spray instilled into the endotracheal tube at the end of the procedure to attenuate the extubation responses. Methods: A total of 45 patients undergoing spine surgery were randomly allocated in three groups. After the return of spontaneous respiration, Group-D: Dexmedetomidine 0.3 mcg/kg IV, Group-L: 10% lignocaine spray 1.5 mg/kg through endotracheal route and Group-P: Normal saline IV given over 60 s. Haemodynamic responses (systolic blood pressure, diastolic blood pressure, mean arterial pressure [MAP], heart rate [HR] and SpO2) were recorded before and after administration of drugs and also duration of emergence, extubation, quality of extubation and post-operative sedation level were evaluated. Results: The increase in MAP and HR during extubation was significantly less in Group-D than Group-L and Group-P, 2 min after administration of the respective drugs (P < 0.05). There were no significant differences in the grade of a cough after extubation and post-operative sedation level. Conclusion: Dexmedetomidine (0.3 mcg/kg) attenuates haemodynamic response better than lignocaine spray (1.5 mg/kg) during emergence and extubation. It also provides smooth extubation and easy recovery without any post-operative sedative effect.

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