From owner-biophysics@net.bio.net Sat Nov 28 22:00:00 1998 Path: biosci!agate!newsfeed.berkeley.edu!news.maxwell.syr.edu!ix.netcom.com!news From: flefever@ix.netcom.com(F. Frank LeFever) Newsgroups: bionet.biophysics,bionet.microbiology,bionet.neuroscience Subject: Re: The truth is out there Date: 29 Nov 1998 02:47:08 GMT Organization: ICGNetcom Lines: 87 Message-ID: <73qcjc$jj8@dfw-ixnews3.ix.netcom.com> References: <721spg$cr7$1@nnrp1.dejanews.com> <36449D67.378533CC@pop3.concentric.net> <36449FE2.313F8F3@pop3.concentric.net> <36477CA4.D2FED10@pop3.concentric.net> <3647B373.953F0A70@pop3.concentric.net> <3649B0AF.E720E242@psci.net> <364AAB63.C5056FB9@pop3.concentric.net> <364B5C6D.75E14B08@indiana.edu> <72s9eb$2fe@apple.telalink.net> <36523785.484B17DE@pop3.concentric.net> <912019876.8168.0.nnrp-08.d4e44203@news.demon.co.uk> <73im3f$ogr@dfw-ixnews3.ix.netcom.com> <912075256.24982.0.nnrp-03.d4e44203@news.demon.co.uk> <73l5ki$735@dfw-ixnews8.ix.netcom.com> <912196374.3097.0.nnrp-05.d4e44203@news.demon.co.uk> NNTP-Posting-Host: nyc-ny79-50.ix.netcom.com X-NETCOM-Date: Sat Nov 28 8:47:08 PM CST 1998 Xref: biosci bionet.biophysics:4589 bionet.microbiology:15191 bionet.neuroscience:26081 In <912196374.3097.0.nnrp-05.d4e44203@news.demon.co.uk> "Andrew K Fletcher" writes: - - - - - - -(snip) - - - - - - - - - - - - - - - >could we please have someone put on record the current accepted mechanism >for cerebrospinal fluid circulation and formation? We need to have an >accurate benchmark, so that a new theory for fluid transport may be offered >for discussion. Your idiosyncratic use of the term "benchmark" is a small thing, but alert readers mauy see this as an indication that we are dealing with yet another example of a "private" way of thinking with many implicit private definitions and beliefs which will be impervious to reasoned arguments and evidence which does not fit your private (solipsistic?) "system". However, I'll point out that while one does need to know a current theory if one wants to explicitly argue against it, one can state a new theory with or without knowing the old theory. If you have something to say, SAY it. It is my belief that a new understanding of this phenomenon >will reverse a complete spinal cord injury. > Surely you do not mean the understanding would reverse it (faith healing?). Perhaps you mean that this understanding would lead too the development of effective treatments. If you think you have a "new understanding" and if you think you see a therapeutic method based on this understanding, SAY SO. (And give at least a hint what the new understanding is and what the new therapy might be). - - - - - - -(snip) - - - - - - - - - - - - - I'll repeat my previous comment: >I'd be surprised if the processes were the same (I.e. water transport in trees, CSF formation and transport and absorption). What is your thesis re relevance of CSF circulation to MS? to spinal cord injury? - - - - - - -(snip) - - - - - - - - - - - - - - >Are you familiar with the limit of 33 feet in physics for lifting water up a >single tube under normal atmospheric pressure RE:Galileo and Torricelli? Is this some kind of a joke? (No, unfortunately, it is not; I know that. I just used a common rhetorical device to express incredulity that someone purporting to understand physical principles better than anyone else would say this.) In physics (as in a few other things), SCALE is all-important. Given a tube wide enough so that surface tension effects are negligible, they will not be sufficient to draw fluid along the surface of the tube, hence the alternative method of exhausting the air above the column so that the weight of the air on the fluid communicating with the base of the tube will force it up; the limit, of course, is set by the height of the atmosphere and thereby the weight of the column of air. With a sufficiently small tube, surface tension effects are very large relative to the total mass of fluid, and draw the fluid along the tube (up, down, or sideways, depending on the orientation of the tube)--process known as "capillary action" But what does ANY of this to do with fluid movement in brain ventricles? We are not "pumping" 33 ft using atmospheric pressure, and we are not (so far as main movement through the ventricles is concerned) dealing with tubules so fine as to make us invoke capillary action as a mechanism. F. Frank LeFever, Ph.D. New York Neuropsychology Group .