Mais la polymyxine n'est pas du tout absorbée dans le sang du système gastro-intestinal et n'a d'effet que dans l'intestin et est utile pour le traitement des infections intestinales doxycycline prix Internet en y faisant des achats permettant d’économiser jusqu'à soixante-dix pour cent, tout en étant sûr de la qualité des produits pharmaceutiques.


Health Services. Much of the concern stems “To vaccinate the whole country in 10 days, from the health risks of the vaccine itself, we’d need two to three million workers.” which caused one to two deaths and 14 to 52 Only a few states have come close to that life-threatening complications for every mil- level of preparedness. Nebraska, which had lion doses when it was last used in the 1960s.
one of the highest per-capita smallpox vacci- The vaccine’s fatality risk, however, is one nation rates as of mid-March, benefited from hundredth the average death rate from mo- the zeal of Richard A. Raymond, the state’s Smallpox is not the only bioterror
tor vehicle accidents in the U.S. and one chief medical officer, who personally lobbied agent that Iraq is believed to
200,000th the mortality rate from smallpox, administrators at dozens of hospitals. “Gov- possess. Under pressure from the
United Nations, Iraqi officials

which would be likely to kill 30 percent of the ernment is all about priorities, and this was admitted in 1995 that their
a priority for us,” Raymond says. “An attack laboratories had churned out
U.S. intelligence officials suspect that both may start in a big city, but because Americans these bioweapons:
Iraq and North Korea possess stocks of small- are so mobile, the entire country is at risk.” ■ Botulinum toxin: nerve agent
pox. The big uncertainty is whether terrorists produced by the bacteria that
could spread the disease effectively—spraying for terrorism preparedness at the Centers for cause botulism
the live virus over a wide area is technically Disease Control and Prevention, notes that ■ Anthrax: bacteria that lie
difficult, and a smallpox martyr could not in- vaccinations are not the only defense against dormant in spores; if inhaled, the
fect others until he or she was quite ill. Small- smallpox. New York City, for instance, has bacteria multiply rapidly in the
body, causing internal bleeding

pox experts note, though, that the public an excellent disease surveillance program, in- and respiratory failure
would demand mass vaccinations even if only creasing the chances that epidemiologists one case appeared in the U.S. and that health would be able to identify and contain a small- ■ Aflatoxin: chemical produced by
fungi that grow on peanuts and
care workers might be unwilling to perform pox outbreak. “Overall, New York gets a corn; causes liver cancer
that task if they had not been previously vac- passing grade,” Henderson says. “But they ■ Perfringens toxin: compound
cinated themselves. Says William J. Bicknell of should have a lot more people vaccinated.
released by the bacteria that
the Boston University School of Public Health: They’re doing it, but not as fast as we’d like.” cause gas gangrene
MATH A Digital Slice of Pi
“One of the greatest ironies of the in- entific Computing Center in
ceived and born in the field of pure mathe- matics, through the genius of giants such as recently this marvelous technology had only a minor impact within the field that gave it mathematicians. Euclid discovered the first birth.” So begins Experimentation in Math- integer relation scheme—a way to work out ematics, a book by Jonathan M. Borwein and the greatest common divisor of any two in- David H. Bailey due out in September that documents how all that has begun to change.
Computers, once looked on by mathematical W. Forcade at last found a method to detect the form ±1 ± x ± x2 ± x3 ± . . . ± researchers with disdain as mere calculators, relations among an arbitrarily large set of xn = 0, up to n = 18) have yet to be have gained enough power to enable an en- numbers. Building on that work, in 1995 Bai- tirely new way to make fundamental discov- ley’s group turned its computers loose on eries: by running experiments and observing some of the fundamental constants of math, To the researchers’ great surprise, after emerged in 1996. Bailey, who is chief tech- months of calculations the machines came up COURTESY OF JONATHAN M. BORWEIN AND PETER BORWEIN nologist at the National Energy Research Sci- with novel formulas for these and other nat- COPYRIGHT 2003 SCIENTIFIC AMERICAN, INC.
ural constants. And the new formulas made of pi means that the infinite stream of digits it possible to calculate any digit of pi or log that follow 3.14159. . . must be truly ran- 2 without having to know any of the preced- dom, in the sense that the digit 1 is there ex- ing digits, a feat assumed for millennia to be actly one tenth of the time, 22 appears one hundredth of the time, and so on. No partic- CRUNCHING
ular string of digits should be overrepresent- such an algorithm. A Japanese team used it to ed, whether pi is expressed in decimal, bina- Mathematical experiments require
check very rapidly a much slower supercom- software that can manipulate
puter calculation of the first 1.2 trillion digits Empirically that seems true, not only for numbers thousands of digits long.
pi but for almost all transcendental numbers.
David H. Bailey has written a
“Yet we have had no ability to prove that even program that can do math with
a single natural constant is normal,” laments arbitrary precision. That and the
PSLQ algorithm that uncovered a
tease out the quadrillionth digit of pi. But Borwein, who directs the Center for Experi- new formula for pi are available at
mathematicians, stunned by the discovery, mental and Constructive Mathematics at Si-
began looking hard at what else experimen- mon Fraser University in British Columbia.
“It now appears that this formula for pi A volunteer effort is under way to
verify the famous Riemann
Hypothesis by using distributed
empiricists have advanced on a deeper ques- key that unlocks that door,” Bailey says. He computer software to search for
tion about pi: whether or not it is normal. The the zeros of the Riemann zeta
constant is clearly normal in the convention- have shown that the algorithm links the nor- function. (German mathematician
al sense of belonging to a common class. Pi mality problem to other, more tractable ar- Bernhard Riemann hypothesized in
is a transcendental number—its digits run on eas of mathematics, such as chaos theory and 1859 that all the nontrivial zeros of
the function fall on a particular
forever, and it cannot be expressed as a frac- line. See “Math’s Most Wanted,”
tion of integers (such as 355⁄ 113) or as the so- related (and easier) problems, and you prove Reviews, on page 94.) To date,
lution to an algebraic equation (such as x2 – that pi is normal. “That would open the more than 5,000 participating
2 = 0). In the universe of all known numbers, floodgates to a variety of results in number computers have found more than
transcendental numbers are in the majority.
theory that have eluded researchers for cen- 300 billion zeros. For more
information, visit
But to mathematicians, the “normality” INTERNET A Man, a Plan, Spam
Like most Internet users,Stanford Uni- service providers (ISPs) to prefilter junk. Fed-
eral antispam legislation hasn’t been tried yet, hates junk e-mail—or, as it is formally and unlike state laws—which have been en- known, unsolicited commercial e-mail (UCE).
acted in 26 states since 1997, to little effect— In fact, he hates it so much, he’s put his job on it would have a chance at deterring American the line. “I think it will work,” he says of his spammers operating outside the nation’s bor- scheme for defeating the megabyte loads of ders. Second: offer a bounty to the world’s penis extenders, Viagra offers, invitations to computer users for every proven violator they work at home, discount inkjet cartridges, and turn in. Just try it, he says, and if it doesn’t requests for “urgent assistance” to get yet an- work, he’ll quit his job. He gets to decide on the particular schemes; longtime sparring about the Internet and recently argued before lagh will decide whether it has worked.
the U.S. Supreme Court against the extension of copyright protection, has developed a two- mers] get to send 10 million e-mails and [they] part plan. The first part is legislative: pass fed- know five million will be delivered and 0.1 eral laws mandating consistent labeling so percent will be considered and responded to,” that it would be trivial for users and Internet Lessig explains. “If all of a sudden you make 24 SCIENTIFIC AMERICAN


801645 1095.1099

International Journal of Obesity (2001) 25, 1095±1099ß 2001 Nature Publishing Group All rights reserved 0307±0565/01 $ side effects of orlistat may beprevented by concomitant prescription of natural®bers (psyllium mucilloid)H Cavaliere1, I Floriano1 and G Medeiros-Neto1*1Department of Clinical Medicine, University of SaÄo Paulo Medical School,

Reiter-WB Teilnehmer Antwerpen,Julia Bilzen,Kim Böhnke,Marcel Clasen,Emma Dillenberger,Lisa Gottschalk,Angela Grein,Madita Griche,Lena Grundei,Laura Hartmann,Fabian Herbst,Leoni Hörter,Jule Hörter,Kira Huck,Dorian Jumpertz,Darleen Kliem,Geena Kreuzberg,Carolin Kroeber,Regine Kroeber,Saskia Krupp,Julia Kurz,Laura Kurz,Sarah

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