Fruit fly scanning electron micrograph
Posted on 06/21/2011 11:51:14 AM PDT by decimon
Fruit fly scanning electron micrograph
A light-sensitive protein in the human eye has been shown to act as a "compass" in a magnetic field, when it is present in flies' eyes.
The study in Nature Communications showed that without their natural "magnetoreception" protein, the flies did not respond to a magnetic field - but replacing the protein with the human version restored the ability.
Despite much controversy, no conclusive evidence exists that humans can sense the Earth's magnetic field, and the find may revive interest in the idea.
Although humans, like migratory birds, are known to have cryptochrome in their eyes, the idea of human magnetoreception has remained largely unexplored since pioneering experiments by Robin Baker of the University of Manchester in the 1980s.
Dr Baker used a long series of experiments on thousands of volunteers that suggested humans could indirectly sense magnetic fields, though he never definitively identified the mechanism. In subsequent years, several groups attempted to repeat those experiments, claiming opposing results.
(Excerpt) Read more at bbc.co.uk ...
Aye, a field good story, indeed. Love the way thosee pole dances flux...
If you ever use a large, 3T superconducting magnet, you’ll find that you cannot readily change the field strengths.
An MRI has one huge magnet that is never off and does not change. The “varying mag field” is mechanized by the RF field and is quite small compared to the main magnet. It just needs to be big enough to cause the H atoms to precess at their characteristic frequency. Sort of like plucking a string.
There is considerable energy stored in the mag field itself, and if you want a stronger field, you must “pump it up” fairly slowly as you add energy. Reducing the field means you have to let the field energy go somewhere.
Besides the energy stored in the field, reducing the coil currents can cause the collapsing field to warm up the whole magnet to where it’s not superconducting any more.
When you get in an MRI, you are in a strong DC field that is not changing. It’s only when they start imaging that you get pulses of RF energy, and it’s the inefficiency of the scan coils that make all the noise.
“and I’ll need to figure a way to quantify disorientation”
I imagine that will be difficult, as most all you have are the patient’s very subjective view of their own disorientation and discomfort, which might originate with a physical affect but is immediately thereafter joined by what the patient “thinks” about it, resulting in their “feeling” discomfort or disorientation.
It would be more direct (but maybe more difficult) to find, by trial and error maybe, the neurological path this protein might stimulate, in the brain, and once identified then patients connected to certain “brain scan” imaging systems could be tested, by varying “stimuli” to see if that neurological pathway was stimulated or not, and how much it was stimulated.
That pathway might be identified by using - under very strict guidelines of patients consent - injections of larger than normal doses of the “magnetic receptor” chemical, into an appropriate part of either the eye or the optic nerve? Just guessing.
here is a page of MRI magnet disasters. If they could turn the magnet down, or off, easily, these would not happen.
http://www.simplyphysics.com/flying_objects.html
And here is a strong mag field (two solenoids). In the demo, they cut power to the solenoids, the field collapses rapidly. The energy that was in the field must go somewhere, and it creates a large voltage that causes a bright arc and loud bang. The bigger the field, the more careful you have to be about back EMF, or, there is a limit to how fast you can change the field.
http://www.youtube.com/watch?v=aSmMFog10D0
I’ve used bending magnets at Brookhaven that you had to ramp up and down slowly.
here is a page of MRI magnet disasters. If they could turn the magnet down, or off, easily, these would not happen.
http://www.simplyphysics.com/flying_objects.html
And here is a strong mag field (two solenoids). In the demo, they cut power to the solenoids, the field collapses rapidly. The energy that was in the field must go somewhere, and it creates a large voltage that causes a bright arc and loud bang. The bigger the field, the more careful you have to be about back EMF, or, there is a limit to how fast you can change the field.
http://www.youtube.com/watch?v=aSmMFog10D0
I’ve used bending magnets at Brookhaven that you had to ramp up and down slowly.
I’d have to use a chemical-specific PET scan- an MRI wouldn’t work! lol
No.
Those who I have known in my life with what seems a natural sense of north-south-east-west direction have included females and males (and I myself am male). Conversely I have known both men and women with a truly lousy sense of direction.
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John Edwards and Arnold Schwarzenegger must be deficient that protein.
Anecdote, not data:
I am also female and directionally impaired. My husband can orient himself almost automatically, and if he has been somewhere once, he can get there, again, from anywhere.
I do have a female friend with a good sense of direction, but she is also adept at reading maps.
THIS EXPLAINS EVERYTHING! Ever sense I got that glass I, eye here and there find myself wandering in an aimless circle.
I think this explains why drunks always seem to be able to find their way home.
I usually have a good sense of direction.
I also usually map out the building I am in, in my head. I will stop and retrace myself until I understand the building.
Back in the world of wind up watches and quarts watches, my mother’s biochemistry used to stop watches cold within a few months. She went through tons of them and they would never work after she wore them for a while.
Ha-HA!
I think there are a number of residual senses some of us have that are not yet identified and studied well. Our modern noisy, overstimulated way of life probably deadens a fair amount of such potential abilities. A friend of mine had a Finish mother. They were living in northern Minnesota with no telephone. She seemed to know when a visitor would drop by; and when he went to sea for long periods, she always showed up at the railway station when he finally arrived home without any communication.
On several occasions, when I was shocked by seeing or hearing something, my husband or toddler son sensed what I had seen or heard without my saying anything about it. Later I read the book Psychic Phenomenon in the Soviet Union, and realized that I had the characteristics of what was called a “sender.”
Regarding the possibility that men seem to be better at retaining a sense of physical orientation even though blindfolded, this makes sense. For several million years men probably wandered much further afield hunting moving game. Females probably stayed in one place, or with the group and did not need to have this ability. On the other hand they more often gathered fruit, roots, and nuts in season which requires remembering were static objects are. This probably explains why women can usually find what their husbands are frantically looking for. ;-)
My husband amazes me his sense of direction. He, too, can find a place he has been to only once. He is always surprised that I do not know the way to a place I have visited several times.
When I park my car at a mall or go into a strange building, I must stop and look around to remember the way back.
Map? What’s a map? Maps are very confusing to me; it’s too much too look at, I can’t focus, and I have to turn the map to orient it to the direction I am traveling. I compare it to looking at a page written in German. I see something here and there that looks familiar, but, for the most part, I do not understand. Oh, how I love my navigation system in my car! I used to get lost quite frequently.
I know only 3 women who are good with maps and direction.
Your analysis of the male/female difference seems quite reasonable.
I can always tell my husband where in the refrigerator or in the cabinet an item is located. (Of course, that does not mean that I won’t find him staring right at it and not seeing it. :)
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