Download Rocks suggest unbalanced past

Health&Science
M ONDAY, SE P T E M BE R 11, 20 0 6
Moral
opinion at
odds with
science
Foes of premarital sex
redirect focus from HIV.
L
ately, opponents of premarital sex have shifted focus
from the threat of HIV to
the sheer number of sexually
transmitted infections and the
way some of these come in
many different strains.
Take this passage from a letter recently printed in The Inquirer opposing the use of a vaccine to protect against two cancer-linked human papillomaviruses: “ … Yes, our daughters
may reduce their rates of cervical cancer caused by just two of
the more than 100 strains of
HPV but they could contract
some other sexually transmitted disease that will eventually
kill them.”
To some people, the fact
there are 100
strains of HPV
speaks to the
danger of sex.
To scientists,
it suggests
nothing of the
sort,
since
most strains
aren’t sexually
transmitted.
For them, the
issue poses a scientific puzzle
about the coevolution of humanity and our viruses.
What we do know is that two
strains of HPV cause 80 percent
of cervical cancer cases. Because the vaccine protects
against these, it’s expected to
save lives.
About 13 other strains can
more rarely lead to the disease.
So while it’s true the vaccine
won’t offer perfect protection,
it’s also the case that if you’re
worried about all 100 HPV
strains, even lifelong abstinence won’t shield you.
You can be the most unsullied
of virgins and still get an HPV
from shaking hands with someone or walking barefoot. Some
will cause ugly warts to form on
various parts of your virginal
body.
Why do diseases divide up
into different strains in the first
place? One researcher who’s
shed some light on this is matheSee HPV on C2
SECTION
C
The Philadelphia Inquirer
B
Harvesting
Neurons
From the
Nose
WWW.PHILLY.CO M
Olfactory neurons are
Unlike sensory cells
elsewhere in the body, the
cells in the nose are both
easily removable and very
similar to brain cells.
Researchers are studying
them for clues into mental
illness.
removed through the
nostril. These cells are
then dosed with various
odors and drugs to see
how they react. To date,
scientists have found
differences in cells of
people with bipolar
disorder and are
studying other mental
illnesses.
Brain
Neurons
Olfactory bulb
SOURCE: Monell Chemical Senses
Center; University of Pennsylvania
Olfactory
neurons
Olfactory
epithelium
ROBERT WEST / Inquirer Staff Artist
Olfactory
membrane
Cilia
The
nose
knows
Olfactory neurons,
local scientists have found,
can reveal a lot about
live brain cells and
mental illness. And
they’re easy to study.
Inside
HEALTH & SCIENCE
Faces saved: Portraits
of people whose lives
have been improved by
facial surgery. C2.
Personal Health:
F
By Tom Avril
INQUIRER STAFF WRITER
or the millions of Americans who take drugs to
treat mental illness, about
the only way psychiatrists
can tell whether the medications are working is through observation and asking patients how
they feel. And even when doctors
do find the right drugs, they can’t
explain exactly why the meds are
effective.
It’s the glaring void at the heart of
mental health treatment. No one,
from the scientists developing
drugs to those who prescribe them,
is able to examine the diseased tissue: the cells of the human brain.
Enter Nancy Rawson, a cell biologist at Monell Chemical Senses Cen-
ter in Philadelphia. She does it
through the nose.
Working with colleagues at the
University of Pennsylvania and Thomas Jefferson University, Rawson
takes advantage of a scientific curiosity: The sensory cells in the nose,
unlike those elsewhere in the body,
are very similar to neurons in the
brain, Rawson says. And they can
be easily plucked out for study, a
few hundred at a time, because they
grow back.
In recent years, researchers have
developed several methods to probe
the mind, from analysis of spinal
fluid to imaging methods such as
MRIs and PET scans. But looking at
olfactory neurons — located high in
the nose, directly connected to the
See NOSE on C3
TOM GRALISH / Inquirer Staff Photographer
Dr. Edmund Pribitkin harvests neurons from the upper nose of healthy
volunteer Jerome Lennon at Thomas Jefferson University.
All-terrain vehicles
unhealthy for kids. C2.
Earth once may have spun
in more than one direction:
Magnetic evidence points to
the center of mass changing.
ARTS &
ENTERTAINMENT
Live Arts/Philly Fringe:
You’re invited to Lee
Ann Etzold’s bizarre
and funny dinner party,
“P’s & Q’s.” C8.
W
hile studying pieces of 800
million-year-old limestone
from Norway, scientists
found the Earth may once have
been seriously out of balance, they
reported last month in the Geological Society of America Bulletin.
Like little compasses frozen in
time, magnetic grains embedded in
successive layers of rock showed an
apparent large movement of the
North Pole over several million
years.
Philadelphia Museum of Art
PUBLIC PROGRAMS
But the scientists say it doesn’t
seem that the pole and the Earth’s
axis of rotation actually “moved.” The
samples suggest that while continuing its regular daily rotation about
the polar axis, the Earth may also
have slowly spun a sixth of a turn in
another direction at the same time.
The big move could have been
due to some sort of subsurface imbalance — an upwelling or downwelling in the Earth’s mantle that
shifted the planet’s center of mass.
If true, it is the most dramatic example yet of a phenomenon known
as true polar wander, which has occurred to a much lesser degree at
other periods in history.
The spin shifted the continents to
unfamiliar places. Australia
was up above the equator,
said Princeton University geologist Adam Maloof, who
helped gather the rocks.
Magnetic grains in rocks
from a few million years
later suggest that the imbalance subsided and the
Earth returned to its original orientation.
The Norwegian rocks
were not consistent with other explanations for the alignment
of the magnetic grains, such as continental drift, Maloof said. But their
hypothesis will be tough to prove,
since few rocks remain from back
then.
One of the few places with rocks
from the correct period is Australia.
So Maloof and company are going
Down Under this summer.
— Tom Avril
Get Smart!
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For more information,
visit philamuseum.org
or call (215) 684-7580
BETO ALVAREZ / Inquirer Staff Artist
Rocks suggest unbalanced past