(1) You should become versatile with the use of the electrophysiological
(2) You will achieve the above in the context of learning about physiology
A few tips on using your Macintosh
Most people primarily use a "WinTel" (Intel chip running Microsoft
Windows), sometimes called a PC ("personal computer" somehow came
to mean this type of computer, originally an IBM work-alike). That is why
I thought this mini-tutorial might be useful, since the PowerLabs are based
on the Macintosh G4 towers using Mac OS 9.x.
Make a folder for anything you want to save
It is very useful to be organized (i.e. to be a good file clerk). Folder
(Mac) = Directory (PC). Double click on the hard drive and you will find
a folder I made called Physiology. Double click Physiology. Pull down under
File to New to Folder. Click on the title (Untitled folder) and delete this
name and name your own folder. Remember how to find your way to your folder
Pulling down under the Apple logo (upper left), we get the Apple menu items.
I've added aliases to some programs we will use under the Apple menu. I
have these programs at the top of that list by putting an exclamation point
(!) to get them ahead of the rest of the alphabetized items.
Toggling from program to program
The upper right will show the program you are using, and pulling down from
the upper right will let you switch to another program that is already open.
"Minimizing" an application
Sometimes your application fills the screen and you want to see something
on the desktop behind the application that is running. Pulling down under
the upper right gives you the chance to hide your application. This is familiar
to PC aficionados (and Mac OSX) as clicking to minimize. The program jumps
back to the foreground just by pulling down from the upper right to that
program (the logo is lighter when it is hidden).
Why Mac in a PC world?
(1) Before Windows 95, PCs were really user unfriendly, while Macs from
the mid 1980's were intuitive.
(2) Mac also stayed alive in a David (Mac) vs. Goliath (PC) world by targeting
schools, so many people knew how to use a Mac.
(3) In general, a Mac could always do anything a PC could do, but there
was a time when many things, especially imaging, and, for you folks, physiology,
could only be done on Macs.
That is why, even though SLU reflects the general population (PC > Mac),
the Science and Math departments still have a lot of Macs.
How best to save your work to home
These Macs have a zip drive (I think 100 MB). While they make Mac formatted
Zips, it is important to know that Macs can read PC formatted Zips. (The
reverse is rarely the case.) So I always use a PC Zip so I can carry stuff
from the Mac to the PC or the PC to the Mac.
Tutorial on writing a paper with a reference data base
Biologists writing papers and grants not only use word processors, they
use reference data bases. Consider the differences in how citations appear
[a] in the paper and [b] in the references. Examples:
(1) J. Biol.
Chem., [a] (author, date), [b] numbered, alphabetized, most information
but not title.
(2) The FASEB
J., [a] (number), [b] numbered, but in order of appearance, all information.
Also, there are many variations on style, like whether the date is in parentheses
and whether the volume is bold.
Suppose that for 5-10 years, a PI (principal investigator) is working in
a sufficiently restricted area that (s)he cites many of the same papers
in the references of many papers or grants. Suppose also that these are
submitted to several journals and agencies. Or even considder, perish the
thought, that J. Biol. Chem. rejects your paper but you want to try to publish
it in the FASEB Journal. You could spend a lot of time re-typing the references
in a different specific format. In order to avoid this tedious chore, references
are typed one time and maintained in a reference data base where the program
(here we will demonstrate Endnote) can be used to set the style for a particular
journal. It is also possible these days (though we will not demonstrate
it this time) to obtain the reference from the National Library of Medicine
(and thus not to have to type it into your data base at all). If the style
of a particular journal of interest is not in the menu, you can make your
Using system 9 on the old G4's I've set up a small exercize. Pull down under
the Apple (upper left) to launch !Endnote. You will be asked which data
base to open (and where it is). On the Macintosh hard drive is a folder
called Physiology, and, in there, is a folder called Dr. Stark, and in there
is a file called "New Endnote ref 95." Open that, and you'll see
the many papers I've been citing in papers I've been writing. Double click
one and you will see how all the information is entered.
As a reminder, you can switch from program to program on the Mac by just
clicking on the document you are using (if you can see it) or pulling down
under the upper right to select the program you want to toggle to. Pull
down under the Apple to launch WordPerfect. Write a little text. In the
old days, people always typed The phrase "The quick brown fox jumps
over the lazy dog" to test typewriters because it used all the letters
in the alphabet. Go to EndNote. Click on a reference. Pull down under edit
and copy. Click over to Word Perfect and pick a place you want to pretend
this reference is relevant and go under edit for paste. Note that all that
shows up is author, year, and a #number identifying the data base entry,
all in brackets. The brackets signal the program that that is a reference.
Do this several times with several different references Save it (give it
a name and select where you are saving it). Go to Endnote. Pull down under
styles, and you will see some styles I've written and used. Pick one. Under
paper, pull down to scan and get a window. The number 1 is good, 0 means
you have used brackets for something other than a reference which is no
real problem, 2 or more means that Endnote cannot determine which reference
you mean (and that is a problem). If you did what I told you, you will have
only 1's. Pull down under paper to format and it will default to save a
WordPerfect file with your name followed by the journal you selected (note
where it is saved). Now click to WordPerfect and open this new paper and
note that the references are added at the end and, in the text, the citations
are made in a way that is used for that journal.
Working with the computer interface
[Everything will probably already be on correctly.]
(1) The amplifiers have no on-off switch, so we handle that by plugging
(2) These PowerLabs were purchased when input of such an interface into
the computer was via SCSI, and the general rule is that the SCSI device
should be on before the computer (not
hot-swapable like USB).
(3) After the PowerLab is on, turn on the computer with the tower or the
Recording with the force transducer
(1) Launch Chart. Note that there are 8 channels, the bottom 4 of which
are bogus since there are only 4 inputs, and the bottom 4 are turned off.
(2) Turn off 2, 3, and 4 and pull down the bottom lines to the bottom to
fill the screen with channel 1.
(3) Feed the force transducer into the bridge amplifier (x1 gain will work),
and feed that into the PowerLab (gain of 100 will be sensitive enough).
[gain is second up-down arrow toward upper right]
(5) Note that the trace might be off scale - and here the position on the
bridge helps a lot. It's a 10 turn pot (potentiometer = variable resistor).
(6) Get the trace centered and try the force transducer with some little
(7) Change the gain and notice the difference in size of recorded finger
twitches. [understanding gain is fundamental]
We can calibrate the force transducer
(1) Note that the ordinate is in mV (which definitely does not reflect force).
(2) Start the record (on screen), put on a 5 g (or 10 g) weight, note the
deflection (about 10 mV [or 20 mV])
(3) Understanding gain is fundamental, as stated above. What happens to
the deflection for the weight when the gain is switched one step up or one
(4) stop the record.
(5) Set the cursor [carefully!] on the low and high and note that you can
see the readings (toward upper right)
(6) Pull down under units of conversion, on two point conversion, set your
low and high readings on the left and 0 and 5 (or 10) on the right [then
(7) Click OK and note that the ordinate is now in g.
(8) Maybe some groups have an upward deflection when the weight is put on.
Why? How can you change this?
For the purist, force, is actually change in momentum per unit of time.
In the cgs system, force is grams times cm divided by seconds squared, called
dynes which is 10 to the -5 newtons (the mks unit). This, despite the transducer
is called a force transducer and the one graph in your text (Silverthorn
3 ed) that has units for tension, Fig. 12-19 has units of kg.
Processing the data on Chart and on the cumputer
I. You can write comments
(1) Click on a part of the record and note the vertical line
(2) Pull down under command to add comment (alternatively the Apple key
on the left or right f the space bar and K)
(3) Type your comment and OK that
(4) a click on the numbered comment will show it to you
II. You can copy and paste (a mini-PhotoShop tutorial)
(1) Under Aple menu items, launch PhotoShop
(2) Select a small portion of your Chart record with the Shift key and the
(3) Go up to the magnifying glass to get a zoom
(4) Under Edit, copy the zoom
(5) Toggle to Photoshop and ask for a new document
(6) It asks you what size and suggests dimensions - these are the size of
what you copied (!) so Just say OK
Photoshop is a very useful program (but I won't show you more than
this for now).
(1) You can add labels like I did on this
picture I present for your cardio lab
(2) You can make complex "plates" like this
one I did for my research
This page was last updated 8/24/05
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