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#301
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"Dr. Barry L. Ornitz" wrote in news:qmxIl.84715
: .... While we have been talking about conventional electrical transmission lines, we can also analyze nerves as a transmission line. A nerve is essentially an electrical transmission line with chemical transducers on each end. When a receptor synapse detects a neurotransmitter, like serotonin or norepinephrin, it sends an electrical signal down the neuron. The neuron is the transmission line. It is essentially an ionic conductor covered with a fatty substance known as myelin. The result is a distributed resistance- capacitance line. In diabetics, the myelin sheath is partially destroyed and replaced with sorbitol, a sugar alcohol. In addition to being more conductive than myelin, sorbitol has a far higher dielectric constant. Viewing the neuron as a distributed RC line, we have both added shunt conductance and increased the capacitance. It is no wonder that nerve conduction velocity and amplitude both decrease resulting in such things as peripheral neuropathy, usually associated with diabetics. I contracted a disease when I was young, a disease that caused the body's T cells to attack the cells of the mylon sheath (in our terms, the dielectric that separates the =ve and -ve ionic material in the nerve's coaxial cable, effectively shorting the coax. During a week or two of onset of the disease, the doctors performed TDR like tests on nerves in my legs, placing a pair if needles each side of a motor nerve, at each end of the nerve, and pulsing the nerve from a signal generator. The sig gen fired a CRO with a camera and 100' roll film back. They took thousands of pics over the couple of weeks, measuring attenuation and velocity of propagation. Yes, I am aware that there are parallels. Owen |
#302
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Barry,
I see I got the spelling of myelin wrong. I remember things I see, and at that time I couldn't focus on things, never saw the word written, was paralysed and was distressed at drowning in my own secretions because I couldn't swallow and couldn't cough. Anyway, I have got it now, myelin! Owen |
#303
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"Owen Duffy" wrote in message
... Barry, I see I got the spelling of myelin wrong. Don't worry, Owen. Most of the time, I put two "l's" in the word myself! I remember things I see, and at that time I couldn't focus on things, never saw the word written, was paralyzed and was distressed at drowning in my own secretions because I couldn't swallow and couldn't cough. About two years ago I developed phlebitis. I went to the doctor who had Doppler ultrasound tests run. He told me that my circulation was good and that the swelling in the left leg would clear up by itself within a week. But one of my toes swelled up and cracked open. Being a diabetic, I immediately returned to the physician. He told me that I had just enough time to drop by my home and pick up some clean underwear to take with me to the hospital. When I got to the emergency room, admission papers were waiting. I had no idea that septicemia could set in so fast. They amputated two toes, then another, and finally my entire left foot. Meanwhile I had continuous IV injections of some of the world's strongest antibiotics. I lost weight too - from 215 to 155 pounds. Small clumps of dead blood cells were sloughing off my heart valves and one blocked a tiny capillary in my brain causing expressive aphasia. It only lasted about three days, but I will forever empathize with stroke victims. I could do complex math in my head, but I could not speak a complete sentence. Fortunately I started recovering soon after the foot was taken. I am posting this history here as a warning to other diabetics. My HgA1c had been running less than 5.5; most diabetics are considered to have good control if this number is below 7. My point is that even with good glucose control, problems can still develop. I too have had nerve conduction studies. As you said, they stick little electrodes in your muscles and nerve bundles, only now they have fancy microprocessor-controlled machines to do the tests. But the tests are just as painful! The worst thing I remember was the neurologist bragging to his nurse, telling her,"Now if I turn this knob, I can make his big toe rotate counter-clockwise." Thanks for an interesting discussion, Owen. -- 73, Dr. Barry L. Ornitz WA4VZQ |
#304
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![]() "Art Unwin" wrote in message ... On Apr 24, 6:48 pm, dave wrote: There is something going on yeah, more people are understanding that you are full of hot air. I am outa here. awwww, just when it was starting to get to be fun. Why not just review my patent request to get the info patents are only meant for lawyers, they rarely have anything really interesting in them. unless of course yours is written like the faster than light antenna that also makes plants grow faster. |
#305
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On Apr 25, 10:22*am, "Dave" wrote:
"Art Unwin" wrote in message ... On Apr 24, 6:48 pm, dave wrote: There is something going on yeah, more people are understanding that you are full of hot air. I am outa here. awwww, just when it was starting to get to be fun. Why not just review my patent request to get the info patents are only meant for lawyers, they rarely have anything really interesting in them. *unless of course yours is written like the faster than light antenna that also makes plants grow faster. Art seems to think that getting a patent validates an idea. In fact devices/ideas that claim to violate known laws of physics are easiest to patent as they will have little to no conflict with other patents. Jimmie |
#306
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Dr. Barry L. Ornitz wrote:
I too have had nerve conduction studies. I also. The voltage getting to the nerves in my feet is 2% of normal. -- 73, Cecil, IEEE, OOTC, http://www.w5dxp.com |
#307
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Cecil Moore wrote:
Dr. Barry L. Ornitz wrote: I too have had nerve conduction studies. I also. The voltage getting to the nerves in my feet is 2% of normal. That's because you're longer than anyone else. 73, Tom Donaly, KA6RUH |
#308
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Tom Donaly wrote:
That's because you're longer than anyone else. Well, just longer than most. The doctor says that when the distance from my spinal column to the numbness in my legs gets equal to the distance from my spinal column to my fingers, they will also start to get numb. It's something that happens but nobody seems to know why. -- 73, Cecil, IEEE, OOTC, http://www.w5dxp.com |
#309
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Cecil Moore wrote:
Tom Donaly wrote: That's because you're longer than anyone else. Well, just longer than most. The doctor says that when the distance from my spinal column to the numbness in my legs gets equal to the distance from my spinal column to my fingers, they will also start to get numb. It's something that happens but nobody seems to know why. That sounds like something not to look forward to. You'd think medical researchers would be able to at least hazard a guess. I have a friend with a similar problem and the same response from his doctors. 73, Tom Donaly, KA6RUH |
#310
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On Apr 11, 3:58*am, Helmut Wabnig hwabnig@ .- --- -. dotat wrote:
On Thu, 9 Apr 2009 20:05:20 -0700 (PDT), Art Unwin wrote: I made a helical end fed antenna that is inside a cone shaped reflector The reflector is made from 1/2" mesh steel with an aluminum foil liner and connected to the braid of the feed coax. No baluns are used, just direct connections. I was surprised to hear signals from the rear! I thought that a dish reflector prevented such signals getting to the receiver. So what can be wrong with the reflector or can signals get reflected back from the frontal area? Antenna is at a 40 foot height Any ideas as to what the fault could be? Regards Art I have no experience with dishes thus the question Note, the helical antenna does not protrude beyond the dish envelope. Art How do you know? The "rear" signals may come from the front side actually, having been reflected by your neighbours house, or distant mountains, or anything in between. w. Helmut I do not know if the rear signals were as you suspected., It is extremely windy here in the midwest for the last few days so I took off the new dish of it's ground stand and placed the dish in a corner outside the house with a TOA that I assume is about 10-15 degrees. Again I got rear signals but I noticed the coverage was very narrow and maybe more than one. So next two weeks or so I will repeat the test but also play around with the elevation to see if there are other observables to determine if you are correct. I am playing with circular polarisation which is a new experience for me and I believe that is capable of picking up reflections that one does not normally see with planar designs Best regards Art |
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