Slate eBook Club
October 2003
Ten Timeless Explainers, Take Two
Geomagnetic
Storms Brendan I. Koerner
How Are Ticker
Symbols Allotted? Brendan I. Koerner
What Weird Futures
Can You Buy? Brendan I. Koerner
Did the Supremes
OK Truth Serum? Brendan I. Koerner
Was Liberia Founded
By Freed U.S. Slaves? Mary Kay Ricks
How Does Corking
a Bat Help a Hitter? Brendan I. Koerner
Why Geld a
Racehorse Like Funny Cide? Brendan I. Koerner
What's the Skinny
on Fats? Ed Finn
How Much of Our
Food Is Bioengineered? Brendan I. Koerner
Which Implants
Look Fake? Brendan I. Koerner
Geomagnetic Storms
By Brendan I. Koerner
Posted
Friday, October 24, 2003, at 11:24 AM PT
A strong geomagnetic storm is slated to hit Earth today,
and experts warn that power grids and satellites could suffer. What's a
geomagnetic storm?
Think of it as an electrical kick in the pants, courtesy of the sun. Geomagnetic
storms like today's begin with an event called a coronal mass ejection, a geyser of solar gas. A
CME can spout billions of tons of this ionized gas, also known as plasma, traveling
at upwards of 3 million miles per hour. That discharge is carried the 93
million miles toward Earth by the solar wind, a constant stream of particles
emitted by the sun.
Normally, when solar particles reach the Earth, they're deflected by the
magnetosphere, the magnetic field produced by the planet. But in the wake of a
major CME, the solar wind carries far too many ionized particles for the
magnetosphere to handle. Charged particles slip through the defenses, so to
speak, causing the magnetosphere to fluctuate. This produces an intensified ring current, an
electrical current trapped within the magnetosphere. The intensity is so
strong, in fact, that it can create electrical current in voltage transformers
and other power-grid hardware. That's bad news for whomever manages those
grids, as the resulting power surge can knock out service to millions of
customers. Geomagnetic-storm watchers warily mention March 13, 1989, when 6 million customers of Hydro-Québec lost power for an
extended time.
The good news is that geomagnetic storms can also produce brilliant light shows
akin to the aurora borealis, or
"northern lights." (Or, in the southern hemisphere, the aurora australis.) These lights are caused by
milder, more common versions of today's storm and are visible in areas
relatively close to the two magnetic poles. The abundance of charged particles
that will be pounding the magnetosphere today should make for some great skywatching,
at least for those lucky enough to live near the roof or the basement of the
globe. However, the intensity of this particular storm may mean that people
farther south may get a peek, too; the infamous 1989 storm was reportedly
visible in Mexico.
Bonus Explainer: A few
fringe scientists have speculated that there's a link between
geomagnetic activity and mental health, arguing that psychiatric admissions increase
during heavy storms. The mainstream dismisses this correlation as no more
substantiated than reports that the full moon causes people to act strangely.
Explainer thanks the American Geophysical Union.
How Are Ticker Symbols Allotted?
By Brendan I. Koerner
Posted
Thursday, September 18, 2003, at 2:20 PM PT
AOL Time Warner will soon be known simply as Time
Warner, as the media titan tries to shed some dot-com baggage. As part of the
change, the company's New York Stock Exchange symbol will revert from
AOL to the pre-merger TWX. What are the guidelines for picking a ticker symbol?
The ball's pretty much in the company's court, as long as its choice isn't
already in use and won't offend anyone's delicate sensibilities. The NYSE
requires that companies submit their symbol requests at least 20 days before
they mail out notification to shareholders and that they list a first, second,
and third choice. The exchange rarely gives a thumbs-down to the preferred
option. One notable rejection occurred in 1992 and involved Furr's/Bishop's
Inc., a Texas-based cafeteria operator that wanted to disassociate itself from
its floundering holding company, Cavalcade Holdings Inc. But the NYSE denied
the company's application for the symbol FBI, on the grounds that it might
cause confusion with a well-known law-enforcement agency, and Furr's/Bishop's
was forced to remain CHI on the board. (The beleaguered company, later delisted
from the NYSE, eventually changed its name to Furr's Restaurant Group—FRRG
on the ignominious pink sheets—and has since filed for
bankruptcy.)
Some companies select cheeky symbols, rather than mere acronyms. The father of
the trend may be Southwest Airlines, which was first listed as
LUV in 1971—a nod to its origins at Dallas' Love
Field. Other semi-clever tags include BID for auctioneer Sotheby's,
FUN for amusement park operator Cedar Fair, and BUNZ for deli chain Schlotzsky's.
It's a lot easier to come up with something witty if you're listed on the Nasdaq,
as that exchange allows symbols to be up to five letters long; the NYSE sticks
with a 3-letter limit.
Stock symbols date back to the telegraph-inspired invention of the ticker in
1867. The most heavily traded stocks were assigned single-letter symbols, to
speed up communication; the lion's share were railroads, like the Atchison,
Topeka, and Santa Fe (A) and Brooklyn Rapid Transit (B). For years, companies
shied away from the ticker symbol Q, since it was traditionally appended to
bankrupt ventures appearing on the market's board. But Qwest
Communications changed all that in 2000, when it became known as Q
on the NYSE. It joined such current one-letter symbols as X (United
States Steel), F (Ford Motor Co.), and, yes,
A—no longer a railroad, but rather Agilent Technologies.
Explainer thanks J. Taylor Brown of the Hirsch Organization and Meg Ventrudo of the Museum of American Financial History.
What Weird Futures Can You Buy?
A
guide to online prediction markets.
By Brendan I. Koerner
Posted
Tuesday, July 29, 2003, at 2:54 PM PT
The Pentagon has scrapped its plans to
operate the Policy Analysis Market, which would have allowed online traders to
wager on the likelihood of future terrorist attacks. Aside from commodities
like pork bellies, what sorts
of futures can wannabe brokers buy and sell?
A whole galaxy, thanks to the proliferation of Internet-based prediction markets, also
known as decision markets. These online bazaars allow punters to plunk down
money, real or imagined, on the potential of films, ideas, or the U.S. military's success in snagging Saddam Hussein. It may sound
like nothing more than glorified sports gambling, but many economists believe that such markets
can suss out vital, hidden information about future events—much in the same way
that a soaring stock on Wall Street can indicate that good things are afoot for
the company in question. That's why the Defense Advanced Research Projects
Agency has been funding so much research on the topic, hoping that
prediction markets can assist military planners.
The granddad of online prediction markets is the Iowa
Electronic Markets, which was started in 1988 to forecast the
fortunes of presidential candidates; the market now covers the Fed's interest
rate decisions as well. IEM participants can use real money, with starting
accounts capped at $500. The market is regulated by the Commodity Futures Trading Commission. (Those
with more Teutonic tastes may prefer Wahl$treet, a market for
futures on German politics.)
Sports fans can take advantage of their nightly SportsCenter viewings on the Athletic Stock Exchange. Not much money to be
made here, as the entry fee is $10 and the athletes trade for just a few
pennies. But sports aficionados may enjoy grabbing a share of Bobby Labonte (Ticker
symbol: LBNT) or Hideki Matsui (MATS) and
seeing where fortune takes them. There are also veritable athletic indexes,
jock versions of the S&P 500, like the Quarterback Pool, which
aggregates the fortunes of all National Football League signal callers.
If news rather than sports is your informational pastime of choice, check out
the current-events section at TradeSports.com, an
Ireland-based betting service that made a name for itself when its market more
or less predicted the date of Saddam Hussein's ouster. A future on a Saddam arrest
this month just went up three points, in light of the capture of one of his
chief bodyguards.
Not all prediction markets require that you risk actual cash. By far the most
famous is the Hollywood Stock Exchange, which permits trade in
both "MovieStocks" (pegged to the box-office success of upcoming
releases) and "StarBonds" (tied to the future fabulousness of silver
screeners), all in fictional money. Today, for example, the HSX is bearish on
the soon-to-be-released S.W.A.T.,
down $5.67 on a volume of nearly 7 million shares. Angelina Jolie, whose Tomb Raider sequel disappointed over the
weekend, is also having a rough Tuesday; her StarBond is down a buck.
The Foresight Exchange Prediction Market allows
traders to bet on the likelihood of a range of events, from the resignation of Donald Rumsfeld by October to a
devastating earthquake in the western United States
by 2010. (A celebrity version of the Foresight Exchange is Long
Bets, where pundits are encouraged to lay down a few thousand bucks
on such outré prophecies as whether there'll be a four-day work week in the
year 2070.)
If you ever had trouble making sense of the blogosphere, Blogshares
may help separate the wheat from the chaff. No money's exchanged on this
market—though there is a $500 contest taking place right now—but it does give bloggers
bragging rights as to the popularity of their daily thoughts among Web surfers.
Curiously, Slate resident blog "Kausfiles"
doesn't appear to be listed on the exchange. Explainer eagerly awaits the IPO.
Bonus Explainer: At
first glance, the trading of weather derivatives on the Chicago Mercantile
Exchange may seem like a prediction market of sorts—after all, weather
forecasting seems ripe for such wagering. But these investors are using the
market to hedge their bets, not to get rich off hunches about upcoming weather.
For example, an energy company that craves a long, hot summer in a certain
city—the better for folks to run their air conditioners incessantly—will manage
risk by purchasing futures that predict a cooler than anticipated summer. That
way, they won't get burned so badly if Mother Nature doesn't comply. Since
these investors are interested parties whose betting strategies are designed
solely to manage risk, the weather derivatives market isn't a classic
predictions market.
Did the Supremes OK
Truth Serum?
By Brendan I. Koerner
Posted
Wednesday, September 3, 2003, at 3:50 PM PT
A Time report on Gerald Posner's
new book, Why America Slept,
cites a passage regarding the use of sodium pentothal—or "truth
serum"—on al-Qaida detainees. According to Posner, the Bush administration
believes its use of the drug is legally justified by a 1963 Supreme Court
opinion. What opinion is he referring to, and what does it say, exactly?
Surprisingly, the case Posner alludes to isn't 1963's Townsend v. Sain,
the only Supreme Court decision to directly address the use of truth serum to
extract a confession. Instead, he refers to (without citing by name) Kennedy v. Mendoza-Martinez,
a case that addresses citizenship issues and Selective Service laws and makes
not a single reference to drug-addled interrogations.
Posner contends that administration officials have zeroed in on a famous quip
in the Kennedy opinion, which
was written by Justice Arthur Goldberg. The ruling was in favor of the appellee,
who had been summarily stripped of his citizenship after leaving the country
expressly to avoid military service. In finding that Mr. Martin-Mendoza could
not have his citizenship revoked without due process, Goldberg noted that:
The powers of Congress to require military service for the common defense are
broad and far-reaching, for while the Constitution protects against invasions
of individual rights, it is not a suicide pact.
As David Corn pointed out in Slate last year, Kennedy
is universally considered a liberal opinion, one that protected due-process
rights rather than allowing the government to circumvent them during times of
crisis. So any Bush administration interpretation that used this line to
justify the administration of truth serum might be legally suspect.
More obviously relevant is Townsend,
in which a Florida man convicted of murder appealed on the
grounds that his confession had been extracted with the aid of pharmaceuticals,
specifically a cocktail of Phenobarbital and hyoscine. The doctor who administered the drugs
ostensibly did so to alleviate Townsend's heroin withdrawal; he did not inform
the suspect that hyoscine is the same thing as scopolamine, a form of so-called
truth serum. (For Explainer's 2001 take on the effectiveness of truth serums,
click here.) The Supreme Court granted Townsend's
request for an evidentiary hearing regarding the drugs, finding that the
prosecution's medical experts had erred by not describing hyoscine's
potentially coercive nature. Despite the ruling in Townsend's favor,
conservative scholars argue that the decision is too narrow to settle questions
about the legality of truth serum in every scenario.
Was Liberia
Founded By Freed U.S.
Slaves?
By Mary Kay Ricks
Posted
Thursday, July 3, 2003, at 7:49 AM PT
In Tuesday's Washington Post,
an editorial urging President
Bush to send peacekeepers to civil war-wracked Liberia noted that the country
was "founded by freed U.S. slaves." Is that true?
Not quite. Although some freed American slaves did settle there, Liberia was
actually founded by the American Colonization Society, a group of white
Americans—including some slaveholders—that had what certainly can be described
as mixed motives. In 1817, in Washington, D.C., the ACS
established the new colony (on a tract of land in West Africa purchased from local tribes) in hopes
that slaves, once emancipated, would move there. The society preferred this
option to the alternative: a growing number of free black Americans demanding
rights, jobs, and resources at home.
Notable supporters of transporting freed blacks to Liberia included Henry Clay, Francis Scott Key, Bushrod Washington,
and the architect of the U.S. Capitol, William Thornton—all slave owners. These
"moderates" thought slavery was unsustainable and should eventually
end but did not consider integrating slaves into society a viable option. So,
the ACS encouraged slaveholders to offer freedom on the condition that those
accepting it would move to Liberia at the society's expense. A number of
slave owners did just that.
When the first settlers were relocated to Liberia in
1822, the plan drew immediate criticism on several fronts. Many leaders in the
black community publicly attacked it, asking why free blacks should have to
emigrate from the country where they, their parents, and even their
grandparents were born. Meanwhile, slave owners in the South vigorously
denounced the plan as an assault on their slave economy.
Abolitionist resistance to colonization grew steadily. In 1832, as the ACS
began to send agents to England to raise funds for what they touted as a
benevolent plan, William Lloyd Garrison revved up the opposition with a
236-page book on the evils of colonization and sent abolitionists to England to
track down and counter ACS supporters.
But the scheme had some fans. Slave states like Maryland
and Virginia were already home to a significant
number of free blacks, and whites there—still reeling from Nat Turner's 1831
rebellion, which emancipated slaves had a hand in—formed local colonization
societies. Thus encouraged, Maryland legislators passed a law in 1832 that required
any slave freed after that date to leave the state and specifically offered
passage to a part of Liberia administered by the Maryland State
Colonization Society. However, enforcement provisions lacked teeth, and many
Marylanders forgot their antipathy to free blacks when they needed extra hands
at harvest time. There is no evidence that any freed African-American was
forcibly sent to Liberia from Maryland
or anywhere else.
By the 1840s, the American Colonization Society was largely bankrupt, and the
transported Liberians were demoralized by hostile local tribes, bad management,
and deadly diseases. The U.S. government would not claim sovereignty
over the colony, so in 1846 the ACS demanded that Liberians declare their
independence. In the end, around 13,000 emigrants had sailed to Liberia. Today, vestiges of the emigration can be seen in Liberia's Maryland County, in
the American-sounding names we read in the papers, and, as reported on National
Public Radio, in one Liberian restaurant's offer of Maryland-style fried
chicken.
How Does Corking a Bat Help a Hitter?
By Brendan I. Koerner
Posted
Wednesday, June 4, 2003, at 2:10 PM PT
Chicago Cubs slugger Sammy Sosa is in hot water for using a corked bat in last night's game versus Tampa Bay. How does corking a bat help a hitter?
Corking a bat lightens the lumber, which in turn increases bat speed and, the
conventional wisdom holds, hit distance. Corkers typically drill a hole at the
end of the bat, hollow out the "sweet spot," and fill it with wine
corks or Superballs. The hole is then sealed with a
combination of sawdust and pine tar. The result is a bat that's several ounces
lighter than advertised, though still as long and thick as its heavier peers. A
lighter bat, of course, is easier to whip through the strike zone.
The theoretical edge seems infinitesimal. Assume a corker reduces his bat's
weight by 1.5 ounces. An average major league pitch travels from the pitcher's
hand to the plate in a hair under half a second. The corked bat will give the
hitter an additional five-thousandths of a second to see the pitch, judge it,
and get the bat head moving through the strike zone.
A quicker bat may help a struggling hitter catch up with pitches, but it
actually reduces his ability to smack long drives. The primary equation that
determines a batted ball's distance is p = mv,
where "p" is
momentum, "m" is
mass, and "v" is
velocity. Though a corked bat will travel at a greater velocity, the tail-off
in weight lessens the mass. As a result, sluggers like Sosa will actually see
the length of their moon shots decrease. In his book The Physics of Baseball,
Yale physicist Robert K. Adair estimated that a corked bat
will shave about a yard off a 400-foot tater.
More likely to benefit, then, are slap hitters who specialize in singles. But
the advantage is more psychological than anything else—a corked bat is
essentially a placebo for hitters on the skids. They also splinter more
readily, which makes catching the cheaters a lot easier. Rather than risk long
suspensions, Adair advises, players should opt for lighter bats, perhaps by
using a lighter grain of wood. Or they can just choke up three-quarters of an
inch, which produces the same uptick in bat speed as corking.
Bonus Explainer:
Surprisingly, the same major league baseball rules that outlaw corking make no
mention of minimum or maximum bat weights, although there's a maximum length of
42 inches and a maximum diameter of 2.75 inches. The earliest set of codified
rules for professionals, published in 1857, recommended bats that weighed up to
48 ounces. Today, given the abundance of pitchers who throw 95-mph cheese,
players prefer much lighter bats; the current average weight is about 33
ounces.
Why Geld a Racehorse Like Funny Cide?
By Brendan I. Koerner
Posted
Friday, June 6, 2003, at 12:31 PM PT
If Funny Cide wins tomorrow's Belmont Stakes, he will
become horse racing's first Triple Crown winner since Affirmed in 1978. He would
also be the first gelding, or equine eunuch, to earn the honor. What's the
point of snipping a thoroughbred's manhood, especially since a gelding has no
stud value?
In most cases, gelding is used as an attitude adjuster. Testosterone makes
colts behave quite badly, even violently, toward humans and fillies alike. An ungelded
colt will bite, rear, kick, or whinny uncontrollably and may have to be isolated
from other horses to prevent such behavior. These young male horses also often
refuse to obey a trainer's commands. As human survivors of adolescence can
attest, a preoccupation with sexual needs tends to diminish concentration.
A large number of racehorses, then, are gelded quite young. According to the Jockey
Club, 25.8 percent of thoroughbreds who raced in North America last year were geldings; that figure
doesn't include less glamorous quarter horses, which are also frequently
castrated. The procedure is typically done within the first year of life,
before the horse can develop too many of the aggressive habits of a mature
stallion. Owners are careful not to geld too early, though, as such colts may
not mature physically.
An equine castrato obviously can't have a post-career job as a stud, but that's
not really an issue for most horses. Only a tiny fraction of professional
racehorses possess the stellar bloodlines necessary to earn stud fees. For
every descendent of Alydar that brings in millions from an Arab
sheik, there are scores of horses that could never even show, let alone win, at
Delaware
Park.
That brings up yet another advantage of gelding—longevity. Thoroughbred
superstars, such as the handful that appear in Triple Crown races, retire quite
young, often because they're either put out to stud or slow down markedly after
the age of 4. Geldings, on the other hand, can run successfully for a few years
longer—the legendary John Henry, for example,
was still winning races at age 9. No one's quite sure why this is, but many
trainers speculate that the castration leads to less bulky—and thus less
injury-prone—musculature.
Funny Cide is an exception to the gelding rules, as he was emasculated for
health reasons, not behavior modification. As a yearling, he was a "cryptorchid"—that
is, one of his testicles never dropped, but rather remained lodged inside his
body—and the testicular defect prevented him from walking normally. Had Funny Cide
not been gelded, he likely wouldn't have had any racing career whatsoever.
Bonus Explainer: Funny Cide
is lucky he wasn't born a half-century ago, or his Triple Crown dream might
have been squashed by gelding bias. From 1919 to 1956, horses bereft of
testicles were banned from competing at the Belmont Stakes.
Explainer thanks Karyn Malinowski of Rutgers University.
What's the Skinny on Fats?
How trans and saturated
fats differ.
By Ed Finn
Posted
Tuesday, July 15, 2003, at 11:00 AM PT
The Food and Drug Administration announced last Wednesday
that by 2006 all nutrition labels—which currently list both total fat and
saturated fat—must also detail the amount of trans fatty acids any serving
contains. But as recently as 1999, the agency was considering lumping trans and
saturated fats together, listing both on the "Sat. Fat" line. How
different are the two fats, and is one worse than the other?
The distinction lies in the number of hydrogen atoms each fat molecule
contains. All fat molecules consist
primarily of strings of carbon atoms to which hydrogen atoms can link; in a
saturated fat, every carbon in the chain has as much hydrogen attached to it as
possible (the fat is "saturated" because no more hydrogen will fit).
Unsaturated fats have less hydrogen; trans fats fall somewhere in the middle
and are created when unsaturated fats undergo partial hydrogenation, a process which adds some
hydrogen without fully saturating the fat. (The procedure also bends fat
molecules into the strange shapes, called trans configurations, that give the fats
their name.)
Partially hydrogenated and saturated fats have longer shelf lives than their
unsaturated peers. That's because the extra hydrogen raises the fats' melting
points, making them more stable at room temperature. Trans fats are useful
because they're slightly softer than saturated fats (think margarine vs.
butter). And food producers (well aware that they'd have to list any saturated
fats on the label) also sometimes opt to use trans fats instead so their
products appear more healthful.
Now that the loophole has been closed, snackers will know what they're eating,
although nutritionists are still debating whether saturated or trans fat is
worse for you. Saturated fats—which you'll find in steak, ice cream, and
butter—have been studied for decades, while trans fats—present in doughnuts,
fries and margarine—have been under scrutiny for only the last 10 years. Both
have been proven to increase low-density lipoprotein, your "bad
cholesterol" indicator. LDL transports
cholesterol—a waxy substance that helps rebuild cell membranes and
create hormones, among other things—from the liver to the rest of the body,
where it can accumulate in arteries and cause heart disease.
One thing that helps keep LDL in check is the "good cholesterol"
indicator, high-density lipoprotein, which carries cholesterol back to the
liver. This is where saturated fat starts looking better: It increases
cholesterol indicators across the board, so HDL levels rise as well. Trans fat,
however, raises LDL while reducing HDL levels, and this dangerous double whammy
has set nutritionists on alert.
Trans fats may also be guilty of numerous secondary sins: There are some
indications that they could increase your risk for cancer, diabetes, and even
cause pregnancy complications. That's why the FDA will not put a recommended
daily allowance next to the new trans statistic—any amount of this stuff is bad
for you.
Explainer thanks Dr. Frank Hu of the Harvard School of Public Health; Biochemistry, fifth edition, Berg, Stryer, and Tymoczko, W.H.
Freeman and Co., 2001; and Lippincott's Illustrated Reviews:
Biochemistry, second edition, P. Champe and
R. Harvey, J.B. Lippincott Co., 1994.
How Much of Our Food Is Bioengineered?
By Brendan I. Koerner
Posted
Thursday, May 22, 2003, at 2:12 PM PT
In a speech yesterday at the Coast Guard Academy, President Bush blasted the European Union for restricting the
import of genetically modified foods. How much of the food produced and
consumed in the United
States qualifies as
bioengineered?
A lot more than you probably realize. Two of the nation's biggest crops,
soybeans and corn, are subject to frequent genetic tinkering, often intended to
help them fend off insects. Corn is commonly modified with the addition of a
gene from the bacterium Bacillus thuringiensis; the
resulting plant kills maize-devouring caterpillars. Other added genes bestow
resistance to certain herbicides, which might otherwise decimate the crop.
Approximately 76 percent of last year's American soybean crop was GM, as well
as 32 percent of corn. (Some estimates place the corn figure closer to 50
percent.) As habitual label readers know, soybean and corn products are
ubiquitous on grocery-store shelves, present in everything from Pop-Tarts to veggie burgers to Campbell's tomato soup (which lists "high fructose corn
syrup" as a primary ingredient). No government body keeps precise
statistics, but a popular guesstimate among university researchers is that
around 70 percent of processed foods contain GM ingredients. Considering that
about 90 cents of every dollar spent at the supermarket goes toward processed
foods, chances are you've been unwittingly consuming GM victuals since the
mid-1990s, when they began appearing in stores.
The other two crops that are regularly modified are canola
and papayas. About half of canola consumed in the United States is GM, though the bulk of it comes from Canada. And upward of 90 percent of Hawaiian papayas are tweaked
to ward off insect infestations. [Correction,
June 12,
2003: Hawaiian
papayas are bioengineered to fight the papaya ring spot virus, not an insect.] GM potatoes were phased out three years
ago, due to consumer backlash; the fry-eating public was worried about the
long-term health risks (the FDA does not review individual GM products for
safety), and the middlemen who sell to McDonald's and Burger King refused to
peddle fine-tuned taters. The Flavr Savr tomato, one of the first GM
vegetables, is also out of circulation, but only because it didn't taste very
good.
There are few guidelines regarding the labeling of GM foods in the United States. The Food and Drug Administration
mandates that bioengineered foods be labeled as such only if the nutritive content
has been substantially changed or if a potential allergen (like a peanut gene)
has been added. The European Union, by contrast, has placed a moratorium on the
import of GM foods, a serious blow to American farmers.
Explainer thanks Mike Vayda of the University of Maine and Craig Winters of the Campaign to
Label Genetically Engineered Foods.
[Correction, June 12, 2003: Hawaiian papayas are bioengineered to
fight the papaya ring spot virus, not an insect.]
Which Implants Look Fake?
By Brendan I. Koerner
Posted
Thursday, October 16, 2003, at 12:42 PM PT
An FDA
advisory panel has recommended that silicone breast implants be
allowed back on the market, 11 years after they were banned for the majority of
breast augmentation procedures. The saline implants that have been used in the
interim are often criticized for looking and feeling less natural than their
silicone counterparts. Why have saline implants earned a bum rap?
The viscosity of the filling material is the key, since all implants use
silicone outer shells. As the name implies, saline implants are filled with
simple salt water, a poor analogue for the texture of naturally occurring
mammary tissue. These surgically implanted sacs can feel squishy to the touch,
and they tend to bounce around more vigorously—sometimes painfully so—during
physical activity.
Silicone implants, by contrast, are filled with a synthetic gel, a fluid with a
consistency not unlike thinned-out maple syrup. This liquid more closely mimics
authentic tissue, and over time, silicone gel oozes to conform with the natural
tear-drop shape of a patient's breasts. Saline implants, meanwhile, tend to
retain their round, balloonish quality, and are thus easier to spot with a
cursory glance. Also, saline implants are more prone to noticeable "rippling." (Makers of
saline implants have tried to ameliorate some of these issues by designing
so-called high-profile implants,
which have less width but more "projection.")
One major advantage of saline implants is that leaks are more immediately
noticeable. The viscosity of the gel in a silicone implant means that leaks are
very slow and can be imperceptible for years. Though doctors remain divided
over whether silicone gel can cause cancer, lupus, or other serious maladies,
they generally agree that it's best to play it safe and not allow a synthetic
polymer to seep into breast tissue, so silicone implants must be removed if a
rupture is discovered. The longer a leak persists, the more difficult (and
expensive) it can be to perform the removal and clean up the surrounding
tissue. A ruptured saline implant, on the other hand, is immediately
noticeable, as the fluid seeps out quickly. The saline is naturally absorbed
and excreted by the body, so all the surgeon must do is remove the ruptured
sac.
Implant makers have also experimented with using soy oil as a filling agent. But British women
who received such implants in the mid-1990s frequently reported painful
swelling, the result of leaks that produced an "emulsified yogurt-like
substance," as the Independent
characterized it. They have never been approved by the FDA, and no clinical
trials are currently underway.