Science
Friday > Archives
> 1999
> February
> February 5, 1999:
Hour One: Origin of HIV / No More Morse?
|
Scientists announced this week that they may
have finally traced HIV-1, the virus that causes
AIDS in humans, back to another species of primate
- a subspecies of chimpanzee. While researchers
have long suspected that some African primate was
the source of the virus, this is the first time
that they've been able to narrow it down to a
specific species.
The scientists, based at the University of
Alabama at Birmingham, compared several different
strains of a related virus, known as SIV (for
Simian Immunodeficiency Virus), and found that the
strains most closely related to HIV all came from
one type of chimpanzee, Pan troglodytes
troglodytes. They also found that this chimp's
natural habitat overlaps the area in Africa where
HIV was first detected in humans.
|
|
The variety of chimpanzee that the scientists have
identified as the source is hunted for food in this region.
The researchers speculate that the first transmission to
humans could have come through infected blood which was
passed between species while humans were hunting or dressing
the chimps.
On this segment of Science Friday, we'll talk about the finding and
what it means, both for AIDS researchers and for people trying to protect
the endangered African chimpanzee population.
Then...
|
Signing off after over a hundred and fifty years, Morse code
is on the rocks. Until the beginning of this week, Morse was the
language of distress signals for all ships at sea. Now most ships
will be required to use a new satellite-based system, called GMDSS
(Global Maritime Distress and Safety System) to send their calls
for help.
|
|
There are several reasons for the switch, say its proponents. Morse code
has a limited range on the medium frequency distress band over which it
is usually transmitted; it can't easily carry complex information (though
it is good for shouting "SOS!"); and decoding the signals requires that
a trained operator be listening to the distress frequency. The new system
will help provide homing signals and location information for ships in
addition to other services.
Small pleasure yachts, ships on the Great Lakes, and fishing vessels
are exempt from the requirement - though they may choose to use the
service if they desire. All ships over 300 tons must use the new system,
in which distress signals are beamed from aboard ship to an Inmarsat
satellite, and then to four listening posts around the world.
On this segment of Science Friday, we'll talk about the history of
Morse code - and whether or not the code has a future.
Guests:
Larry Arthur
Director
AIDS Vaccine Program
National Cancer
Institute/Frederick Cancer Research and Development
Center
Science Applications
International Corporation
Frederick, MD
Anthony Fauci
Director
National Institute of Allergy and
Infectious Diseases
National Institutes of Health
Bethesda, MD
Les Kalmus
Amateur Radio Operator
Member, American Radio Relay League
President, Cyberstaff America Ltd.
New York, NY
J. Patrick Allen
President, Mercomms Unlimited
Panama City Beach, Florida
Books/Articles Discussed:
Related Links:
- News
Release from University of Alabama at Birmingham about the finding
- National
Institute of Allergy and Infectious Diseases Home Page (NIAID), National
Institutes of Health
- Centers
for Disease Control and Prevention Home Page
-
- The International
Maritime Organization's home page
- Global
Maritime Distress and Safety System
- United
States Coast Guard Home Page
-
This segment produced by:
Karin Vergoth
Web producer:
Charles Bergquist
|
