Physiological Factors in the Avoidance of Air Collision

1958 ◽  
Vol 11 (1) ◽  
pp. 73-76
Author(s):  
G. F. J. Perdriel
Keyword(s):  
Cerebral Cortex ◽  
Essential Factor ◽  
Physiological Factors ◽  
Avoidance Manoeuvre

For anti-collision purposes, the identification of an aircraft requires perception of its presence, detection of its track, and determination of its relative altitude. This evaluation will be recorded by the cerebral cortex and give rise to decisions regarding the action to be taken, which will vary from one individual to another. The avoidance manœuvre will be dictated by the situation and the rules of avoidance, and will involve a psychomotor coordination. Time is the essential factor in the chain of events, since the speed of the pilot's reactions will reduce the possibility of collision.

scholarly journals UV Sensitivity of Free and Immobilized on Chitosan Matrix Proteases

2020 ◽  
Vol 2 (1) ◽  
pp. 17
Author(s):  
Svetlana Pankova ◽  
Marina Holyavka ◽  
Valeriy Artyukhov
Keyword(s):  
Uv Irradiation ◽  
Living Systems ◽  
Essential Factor ◽  
Active Centers ◽  
Santa Ana ◽  
Uv Sensitivity ◽  
Chitosan Matrix ◽  
Lowry Method ◽  
The Stability

UV irradiation is an essential factor in natural and artificial climate in modern environmental conditions, which has a constant effect on living systems. Collagenase, bromelain, ficin, papain (Sigma-Aldrich: St. Louis, MO, USA) and trypsin (MP biomedicals: Santa Ana, CA, USA) were the objects of this study. The substrate for hydrolysis was BSA (Sigma-Aldrich: St. Louis, MO, USA), the carriers for immobilization were chitosans (<100, 200 and 350 kDa) and chitosan succinate (Bioprogress: Shchyolkovo, Russia). The protease immobilization was carried out by the adsorption. The determination of the protein amount in samples and their catalytic activity was carried out by the modified Lowry method. UV irradiation of proteases was performed using doses 151–6040 J/m2. By the degree of photosensitivity, hydrolases can be arranged in the next row: collagenase → bromelain → ficin → papain → trypsin. Adsorption on a chitosan and succinate of chitosan leads to an increase in the stability to ultraviolet light of heterogeneous (immobilized) biocatalysts compared to free enzymes. Photoprotective effect of the chitosan may be due to the following reasons: enzyme interact with the chitosan to form photo resistant complexes; сhitosan screens active free-radicals, preventing the photooxidation of a certain number of amino acids, including the active centers of the studied enzymes under the influence of UV irradiation.

Immunohistochemical investigation of cerebral ischemia during recirculation

1985 ◽  
Vol 63 (6) ◽  
pp. 922-928 ◽  
Author(s):  
Toshiki Yoshimine ◽  
Kazuyoshi Morimoto ◽  
Joan M. Brengman ◽  
Henry A. Homburger ◽  
Heitaro Mogami ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Cerebral Cortex ◽  
Cerebral Ischemia ◽  
Immunohistochemical Method ◽  
Ischemic Lesion ◽  
Content Type ◽  
Creatine Kinase Bb ◽  
Ischemic Period ◽  
Temporary Occlusion

✓ Immunohistochemical methods for the determination of tubulin, creatine kinase BB-isoenzyme, and astroprotein-glial fibrillary acidic protein were used to investigate recovery of the ischemic lesion after temporary occlusion of a common carotid artery in the gerbil and the evolution of the postischemic lesion following reperfusion. One group of gerbils was followed from 15 minutes to one month after an ischemic period of 30 minutes, and another group was examined after 7 days following an ischemic period of 5 to 30 minutes. It was found that the postischemic lesion, visualized as loss of the immunohistochemical reaction for tubulin and creatine kinase BB-isoenzyme, evolved within 60 minutes after reperfusion in the hippocampus and cerebral cortex and within 3 hours in the caudoputamen and thalamus. Resolution of the preexisting ischemic lesion was possible only after an ischemic period of less than 10 minutes in the cerebral cortex and caudoputamen and less than 15 minutes in the thalamus. In the CA1-CA2 region of the hippocampus, the ischemic lesion already existed after an ischemic period of 5 minutes and was mostly irreversible. The immunohistochemical method of testing for different cellular and subcellular components was very useful for investigation of cerebral ischemia and may also be advantageous for investigation of other pathophysiological conditions of the nervous system.

Determination of current density distributions generated by electrical stimulation of the human cerebral cortex

1993 ◽  
Vol 86 (3) ◽  
pp. 183-192 ◽  
Author(s):  
Surendar S. Nathan ◽  
Saurabh R. Sinha ◽  
Barry Gordon ◽  
Ronald P. Lesser ◽  
Nitish V. Thakor
Keyword(s):  
Cerebral Cortex ◽  
Electrical Stimulation ◽  
Current Density ◽  
Human Cerebral Cortex ◽  
Density Distributions ◽  
Stimulation Of
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