books
Beyond Star Trek: From Alien Invasions to the End of Time—Lawrence M. Krauss. In
this follow-up to his successful book The Physics of Star Trek, Krauss uses the television
show The X Files and the movie Independence Day, among others, to illustrate
cosmological conundrums. For example, aliens like those in Independence Day would
probably have arrived on Earth only to find it devastated by weather brought about by the
gravitational effects of their spaceships. The basics of quantum mechanics, advances in
warp-drive systems, and the possibility of extraterrestrial life are also deftly considered.
Originally published in hardcover in 1997. HarpPL, 1998, 190 p., paperback, $12.00.
Doubt and Certainty: The Celebrated Academy Debates on Science, Mysticism, Reality
in General on the Knowable and Unknowable, with Particular Forays Into Such Esoteric
Matters as the Mind Fluid, the Behavior of the Stock Market, and the Disposition of a
Quantum Mechanical Sphinx, to Name a Few—Tony Rothman and George Sudarshan.
The subtitle certainly conveys the text's gist, but readers may be interested to know that
these witty authors are physicists. Their Western and Eastern philosophies flavor these
dialogues concerning issues in modern physics and the clashing or meshing of New Age
ideals. In what they describe as a "cross between Plato's Republic and the 1001 Nights,"
Rothman and Sudarshan reinvent Plato's academy, melding their thoughts with those of
their ancestors and contemporaries. Each section is prefaced by background on its
subject and is concluded with a puzzle or exercise. Perseus, 1998, 320 p., hardcover,
$25.00.
The Handy Geography Answer Book—Matthew T. Rosenberg. The Handy Physics
Answer Book—P. Erik Gundersen. Fans of The Handy Science Answer Book and its
progeny should find these two offshoots to be equally appealing methods of nourishing
one's curiosity about the physical world. Not just a book about maps, the geography
volume answers queries about climate, exploration, disasters, and individual continents,
such as: What are the four climatic regions of the Andes, and what was the Ottoman
Empire? A concluding section lists vital statistics for 192 countries. The physics book
explores more than 800 fascinating aspects of physics, including sound, waves, fluids,
thermodynamics, magnetism, and electricity. Readers discover the difference between
center of mass and center of gravity, how a compass is made, and how objects maintain
an orbit around Earth. Both books Visible Ink, 1999, 462 p./415 p., color plates/b&w illus.,
paperback, $19.95.
Magnitude 8: Earthquakes and Life Along the San Andreas Fault—Philip L. Fradkin. For
nearly 20 years, Fradkin has lived within shouting distance of the point on the San
Andreas Fault that moved 20 feet in 1906. His proximity to one of the most turbulent faults
in the United States informs his discussion of the natural elements of earthquakes and the
impact of this phenomenon on the cultural and daily lives of people who reside near faults.
Fradkin blends these elements into his consideration of the outcome of a future magnitude
8 quake, the difficulty in predicting quakes, and the rationale of fault-dwellers. H Holt & Co,
1998, 336 p., hardcover, $27.50.
The Pattern on the Stone: The Simple Ideas That Make Computers Work—Daniel Hillis.
Using analogies befitting a child, Hillis tells how computers compute. He begins by
imparting Boolean logic through a demonstration of a machine that plays tic-tac-toe. Then,
he describes a universal construction set in terms of the shortcomings of Lego blocks. He
goes on to aptly describe Turing machines, algorithms, heuristics, and encryption. Hillis
gift is his ability to convey the logical processes of computers that begin with switches and
circuitry and escalate to self-organizing learning ability relevant to parallel computing
systems. Basic, 1998, 164 p., illus., hardcover, $21.00.
Sutton Hoo: Burial Ground of Kings?—Martin Carver. On three separate occasions
during the past 60 years, archaeologists unearthed mounds exhibiting unusual burial
tactics in southeastern England. Dating to 600 a.d., these graves of medieval English
aristocrats were swollen with not only human remains but also a bounty of artifacts. Some
individuals were buried in their boats, others were entomed with their horses, art, and
precious metals. Carver attended the last of these digs, and he recounts the content of the
sites and the theories about them offered thus far. Penn, 1998, 195 p., color plates/b&w
photos, hardcover, $29.95.
Straight Talk About Psychiatric Medications for Kids—Timothy E. Wilens. A specialist in
pediatric and adult psychopharmacology at Massachusetts General Hospital surveys the
gamut of childhood mental, emotional, and behavioral conditions treated with medication.
First explaining the conditions and their hallmark symptoms, Wilens then presents
treatment options and facts about associated medications. Early chapters answer
questions about the medicating process and its short-term and long-term effects on
children. A guide to psychotropic medications concludes the book. Guilford, 1999, 279 p.,
paperback, $14.95.
Letters
Warmer than when?
The article "Sizzling June fires up greenhouse debate" (SN: 7/25/98, p. 52) contained
two errors. First, while the 1990s have been the hottest decade since people began
systematic temperature measurements in the mid-1800s, it is not the hottest decade on
record. Even proponents of the theory of human-caused global warming recognize data
indicating Earth has been hotter than it is now many times—most recently around 600
years ago, before the advent of the most recent "little ice age." The current warming trend
began as Earth came out of the little ice age—an important fact that is all too often
overlooked in the global warming debate.
Second, the Kyoto Protocol is not stalled in any Senate committee, since the Clinton
administration has yet to sign it or submit it to the Senate for ratification. The
administration recognizes that the treaty has several problems and has vowed not to
submit it to the Senate until they are addressed.
H. Sterling Burnett
National Center for Policy Analysis
Dallas, Texas
There is little debate about the statement that the 1990s is the warmest decade on
record for global temperatures. Reliable records of global temperatures reach back only
into the 19th century. For earlier times, researchers try to gauge temperature trends from
a much spottier data set, which can hardly be considered a global record.
More important is the question of whether Earth is now warmer than it was earlier in this
millennium. There is evidence that parts of Europe were warm during the so-called
Medieval Warm Period, particularly in the 11th and 12th centuries, but it is far from clear
whether this was a global phenomenon and whether temperatures during this period were
higher or lower than today's. Some parts of the globe did not show any warming back
then, whereas other regions warmed up at different times than did Europe.
The Intergovernmental Panel on Climate Change in its 1995 report said that "it is not yet
possible to say whether, on a hemispheric scale, temperatures declined from the 1112th
to the 1617th centuries. Nor, therefore, is it possible to conclude that global temperatures
in the Medieval Warm Period were comparable to the warm decades of the late 20th
century." The IPCC later said that data from studies of alpine glaciers "suggest that in at
least alpine areas, global 20th century temperatures may be warmer than any century
since 1000 AD, and perhaps as warm as during any extended period (or several
centuries) in the past 10,000 years."
With regard to the Kyoto Protocol, you are correct that the administration has not yet
submitted it to the Senate for ratification. —R. Monastersky
No smoking gun
Your news report "Exposure to smoke yields fetal mutations" (SN: 10/3/98, p. 213)
omitted mentioning the relevant epidemiology. A Medline search yielded four studies that
do not indicate that maternal smoking/passive smoking increases cancer risk among
infants.
These studies directly contradict the statement by NCI's Sholom Wacholder that
epidemiological findings link prebirth exposure to carcinogens with childhood leukemia. I
don't know what studies Wacholder refers to, but they certainly have nothing to do with
maternal smoking.
Steven Milloy
Potomac, Md.
Diabetic Pregnancy Risk Starts Early
Diabetic women who become pregnant typically seek a doctor's advice during the first
trimester. They are told to take care of themselves and to be especially careful to keep
their blood sugar under control. Not only are they up to four times more likely than
nondiabetic women to miscarry, but their babies face three times the normal risk of
congenital defects.
A study in mice now suggests that, in some cases, such counseling may come too late.
The research indicates that apoptosis—natural cell suicide—often goes awry in a diabetic
mouse embryo and wipes out healthy cells. What's more, this damage can occur soon
after fertilization, researchers report in the December Nature Medicine.
If the findings translate to humans, those prenatal consultations should become
preconception visits, says study coauthor Kelle H. Moley, a reproductive endocrinologist at
Washington University in St. Louis.
Apoptosis is a necessary cellular housekeeping process. When cells are no longer
needed, become infected, or have damaged DNA, the suicide process dismantles the
nuclear material and parcels out DNA fragments to nearby cells for disposal.
Earlier research identified a protein called Bax as a key player in this cascade of events.
In people with high blood sugar, such as those with diabetes who don't control their diet or
who fail to take insulin, a surfeit of glucose boosts Bax production. Too much Bax induces
some cells to kill themselves hastily. Moley and her colleagues suspected that high Bax
concentrations might link diabetes to high rates of miscarriage and birth defects.
To find out, the researchers mated male mice with three sets of females: 15 nondiabetic
mice, 18 diabetic mice not receiving insulin, and 14 diabetic mice given insulin injections
just before and after fertilization.
The team extracted embryos from the female mice 48 to 96 hours after fertilization and
found that Bax concentrations in the embryos from insulin-treated females weren't
markedly different from those taken from healthy females. However, embryos from the
untreated diabetic mice—exposed to an abundance of glucose in the mother's blood—had
Bax concentrations nearly eight times as high, Moley says.
To directly assess DNA damage, the researchers used three more sets of pregnant
mice. DNA fragmentation in the embryos of untreated diabetic mice was more than six
times as prevalent as in embryos of the healthy control mice and nine times as high as in
embryos from insulin-treated diabetic mice.
Significant cell death in the embryonic stage may abort a pregnancy—resulting in a
miscarriage—while less damage may cause deformities, Moley suggests. The birth
defects arising from pregnancies in diabetic women include heart damage, limb
deformities, and neural tube defects leading to brain damage.
The new study "is interesting," says David R. Hadden, an endocrinologist at Royal
Victoria Hospital in Belfast, Northern Ireland. "They are making a very reasonable case, a
good case."
Still, the apoptosis explanation doesn't explain why some diabetic women with high
blood sugar go on to have healthy babies, he says. Also, other research indicates that
high glucose concentrations later in pregnancy seem to have deleterious effects, he adds.
Fifty years ago in Europe, roughly one in three diabetic pregnancies "ended in disaster
of some form," Hadden says. Today, that risk has fallen, indicating that prenatal glucose
monitoring reduces the number of developmental problems. Still, 1 in 15 pregnancies in
diabetic women results in some type of congenital defect as compared with 1 in 40 among
other women.
Since research on human embryos is rare, monkey tests could be the next phase of
study. "I think that would really nail down whether [the Bax findings] are a reflection of a
human . . . phenomenon," Moley says. —N. Seppa
Poor winter homes delay bird nesting
A migratory bird that gets stuck with second-rate winter accomodations will achieve only
lackluster breeding success the next summer, hundreds or even thousands of miles away,
a new study suggests.
"Making that link before has been impossible to do," says Peter P. Marra of the
Smithsonian Migratory Bird Center in Washington, D.C. He and his colleagues established
the connection by using a technique that's novel among ornithologists: deducing where a
bird has been by the carbon isotopes in its tissue. Isotopes are forms of atoms with
different numbers of neutrons.
In the Dec. 4 Science, the researchers report that American redstarts that reach their
New Hampshire summer breeding ground early—a big factor in nesting success—have
isotope ratios typical of moist, food-rich winter habitats. Birds that arrive late, however,
show ratios typical of poor, dry habitats.
"Things we're seeing in the breeding grounds are caused by events the previous
winter," Marra explains.
Monitoring redstarts wintering in Jamaica, the researchers found that dominant males
and the tougher females claim forest territories with abundant insects for food. An
underclass of smaller, weaker redstarts gets pushed into scrub, which has fewer insects.
The researchers found that birds in prime winter territories increased or maintained their
weight, but the birds in the slums lost up to 11 percent of their body mass. Come spring,
redstarts in the poor habitat took longer to pack on fat for the flight north, leaving some 10
days later than birds in the forest.
The researchers could not track those particular birds north—a problem with many such
studies. So Marra and his colleagues observed redstarts summering in central New
Hampshire. Late-arriving males tended to be high in carbon-13, like the birds in the inferior
winter habitats. There, birds ate insects that feed on dry-region plants, which typically
build up extra C-13.
Trevor D. Price of the University of California, San Diego welcomes the report as the
first evidence tying bad winters and bad summers in a way he and other researchers had
suspected. "We've finally got some facts," he says.
Scott K. Robinson of the University of Illinois at Urbana-Champaign points out that the
study "certainly indicates there isn't enough good habitat" for wintering redstarts. He
predicts the results will bolster claims that problems in the tropics contribute strongly to
declines of migratory birds. Some scientists still think breeding-ground problems are more
important. However, Robinson says, "I think the jury is still out." —S. Milius
A female redstart from poor habitat may be late to her breeding grounds.
Titanic wreckage still tells a riveting tale
Eighty-six years after the RMS Titanic scraped against an iceberg and sank to the
bottom of the Atlantic Ocean, researchers are still trying to unravel the mystery of what
happened on that fateful night. The iceberg sliced several long slits, each no more than an
inch wide, into the side of the ship. Yet the supposedly unsinkable vessel went down after
no more than 3 hours.
Now, a panel of naval engineers and scientists has concluded that the Titanic owed its
rapid demise in large part to the failure of the rivets that fastened its hull together.
According to a metallurgical analysis of samples retrieved from the wreckage this summer,
the inconsistent quality of the wrought iron rivets weakened them, allowing the ship's steel
panels to rip apart at the seams.
Tim Foecke of the National Institute of Standards and Technology (NIST) in
Gaithersburg, Md., presented results of the analysis this week in Boston at a meeting of
the Materials Research Society.
The panel's conclusion contradicts conventional wisdom, which holds that in the icy
ocean water, the ship's steel hull turned exceptionally brittle and cracked apart. In 1991, a
team of Canadian researchers tested a steel plate fragment from the ship and found that it
was indeed brittle—not only when cold but even at room temperature.
"We believe that brittle steel didn't have much to do with the sinking of the Titanic,"
Foecke says. "[We are] willing to declare the brittle steel theory dead."
The Canadian researchers aren't convinced, though. "I would say—barring a miracle—
the rivets have absolutely nothing to do with the sinking of the Titanic," says James
Matthews, an engineer and materials specialist at the Defence Research Establishment-
Atlantic in Halifax, Nova Scotia.
In 1996, the Marine Forensics Panel of the Society of Naval Architects and Marine
Engineers began investigating the Titanic disaster. Panel chair William A. Garzke Jr., a
naval architect at Gibbs & Cox in Arlington, Va., suspected that the rivets played an
important role. Foecke, a panel member, then analyzed two rivets retrieved during a 1996
expedition to the wreck.
He found that the rivets contained three times the expected amount of silicate slag, an
impurity that strengthens the metal at concentrations of 2 to 3 percent but tends to weaken
it at higher concentrations.
Moreover, the slag ordinarily forms long fibers that run along the length of the rivets,
reinforcing them. At the ends of the rivets, however, Foecke found the fibers turned to a
horizontal orientation. Aligned that way, the layers of iron and slag easily peel apart.
Last August, another expedition brought back more rivets for testing. Foecke found slag
problems in 14 out of 30 samples. The additional data, Foecke says, confirm the rivet
theory, first published in a NIST report issued in February.
Matthews counters, "A lot of things draw interpretations, but they are not indicative of
performance." He adds that the huge forces suffered by the ship when it snapped in two
and hit the ocean bottom could have mangled the rivets.
To bolster their respective theories, both Foecke and Matthews cite the RMS Olympic, a
ship almost identical to the Titanic that was hit by a British warship in 1911. Foecke says
that rivets popped out as far as 15 feet away from the point of impact. Matthews, on the
other hand, focuses on the cracks, characteristic of brittle steel fracture, that propagated
through the hull.
The steel in both ships, and in ships built today, is of a poor grade, Matthews says.
"There are no riveted ships anymore, yet 40 to 50 a year are lost," he reports. "Ships are
sinking now for the same reason," he says—brittle fracture.
The panel now plans to explore a third ship of Titanic's design, the HMHS Britannic,
which rests beneath the Aegean Sea. With more rivet samples, the researchers can get a
better statistical analysis of the material, he explains.
"What sank the Titanic?" Foecke asks. "It hit an iceberg." The question is how it might
have stayed afloat longer, giving time for help to arrive. Instead, more than 1,500 people
perished, memorialized by the riveted steel hull that lies 12,000 feet beneath the waves.
—C. Wu
Cross-section of a rivet from the Titanic.
Gulf War syndrome may signal mental ills
A mysterious and controversial illness said to afflict many veterans of the 1991 Persian
Gulf War may often stem from mood and anxiety disorders rather than wartime exposure
to infectious agents or toxins, a new study finds.
On closer examination, diagnoses of Gulf War syndrome are often replaced by findings
of depression, stress reactions, and related disturbances, reports a team led by internist
Michael J. Roy of the Uniformed Services University of the Health Sciences in Bethesda,
Md.
"Many patients with [Gulf War syndrome] may in fact have treatable mood or anxiety
disorders rather than mystery illnesses," Roy and his coworkers contend in the
November/December Psychosomatic Medicine. Their study, however, does not exclude
the possibility that some Gulf War veterans suffer from an illness sparked by exposure to
toxic substances.
Symptoms linked with Gulf War syndrome include fatigue, headaches, sleep disorders,
and memory loss. There are no clear guidelines for diagnosing this condition, although
veterans need an illness diagnosis to qualify for government medical benefits (SN:
10/15/94, p. 252).
Roy's group reviewed data from comprehensive medical examinations of 21,579
Persian Gulf veterans who had complained of health problems. Of that number, 17
percent exhibited one or more symptoms that can be related to Gulf War syndrome, which
include evidence of infection; another 25 percent displayed signs of Gulf War syndrome
and also of a separate health problem.
The 2,306 veterans who had the most pronounced symptoms of Gulf War syndrome
received further exams by internists, psychiatrists, and infectious disease specialists.
These close evaluations yielded large drops in the proportion of diagnosed symptoms that
the clinicians attributed to Gulf War syndrome. The physicians assigned just 18 percent of
all diagnosed symptoms to the syndrome in these follow-up exams, compared with 30
percent in the initial assessments of all veterans with any signs of Gulf War syndrome.
After these intensive evaluations—particularly those conducted at Walter Reed Army
Medical Center in Washington, D.C., which convenes weekly meetings of physicians and
mental health workers to discuss diagnoses—the physicians often noted the presence of
mood disorders or post-traumatic stress disorder.
Symptoms of Gulf War syndrome may often arise as part of mood and anxiety
disturbances, the scientists conclude. These mental disorders are often accompanied by
the exact same problems—fatigue, headaches, sleep disturbances, and memory loss.
The new study raises concerns about the inappropriate labeling of psychiatric ailments
such as Gulf War syndrome, comment psychiatrist Allen J. Frances and psychologist Jean
C. Beckham, both of Duke University Medical Center in Durham, N.C., in an
accompanying editorial. Long-term investigations, however, will be required to address
whether some Gulf War veterans indeed suffer from a distinct illness caused by toxic
exposure, they say. —B. Bower
Turtle genes upset reptilian family tree
Paleontologists have long viewed turtles as evolutionary slowpokes, the sole survivors
of an ancient group that later gave rise to other reptiles, birds, and mammals. A new
genetic analysis, however, dramatically redraws the evolutionary tree of vertebrates and
challenges conventional wisdom on turtle origins.
"The slow-moving turtles that everyone thinks are slow in terms of evolution turn out to
be fast evolvers," says Axel Meyer of the University of Konstanz in Germany, who
collaborated in the study with Rafael Zardoya of the National Museum of Natural Sciences
in Madrid.
Turtles have always stood apart from lizards, snakes, crocodiles, and other reptiles
because of their skulls. Most reptiles, together with birds, have two holes on each side of
their skull, to the rear of their eyes. Paleontologists label these animals diapsids. Turtles
lack any such holes and so are the only living anapsids, a group that includes fossils of
the most primitive vertebrates capable of living entirely on land. Mammals are termed
synapsids because they evolved from animals with one skull opening behind each eye.
According to the standard evolutionary story, turtles retain some characteristics of the
ancient anapsids. As such, biologists have regarded them as an example of the stock
from which reptiles, birds, and mammals later evolved.
Zardoya and Meyer explored this hypothesis by comparing the sequences of two
mitochondrial genes from turtles to those of iguanas, tuataras, alligators, chickens, and
mammals. Turtles fell squarely within the modern diapsids rather than in their expected
position on a branch outside the group, the scientists report in the Nov. 24 Proceedings of
the National Academy of Sciences.
Their results lend support to a 1996 analysis of reptile fossils, which also suggested that
turtles evolved from diapsids, says Olivier C. Rieppel of the Field Museum of Natural
History in Chicago. The two studies do not agree in their details, though. Rieppel and a
colleague found that turtles were closest to snakes and lizards, whereas Zardoya and
Meyer place turtles nearest to alligators and birds.
Both cases suggest that turtles evolved from diapsids and then lost the characteristic
skull holes. If so, turtles would not make a good model for early land-dwelling vertebrates.
Critics counter, however, that both studies have major flaws. The new gene analysis, for
example, included only a few types of animals. "If you sample only a limited number, you
tend to get very, very wrong [evolutionary] trees," says Michael S.Y. Lee of Monash
University in Melbourne, Australia. —R. Monastersky
Turtles: An evolutionary enigma.
Newer pennies pose a special toddler risk
Toddlers have a habit of mouthing anything within reach, including coins. Last year
alone, some 21,000 youngsters ended up in emergency rooms throughout the United
States after ingesting these candy-shaped disks—mostly pennies. New evidence indicates
that swallowing pennies minted after 1981 poses an especially dangerous threat to
children and pets.
Apart from the obvious choking hazard, the pennies can trigger stomach ulcers and
erode into circular blades of tissue-ripping zinc, a physician reported this week in Chicago
at the annual meeting of the Radiological Society of North America.
Pediatric radiologist Sara M. O'Hara stumbled upon the problem in March 1997, when
parents brought a 2 1/2-year-old boy into the Duke University Medical Center in Durham,
N.C. Having watched in horror as their child ate a penny and nearly choked, they wanted
to know what to do next. Once O'Hara X-rayed the boy and confirmed that the penny was
in his stomach, the emergency room staff advised the parents just to wait for the penny to
pass in the stool.
But 4 days later, the boy was unwilling to eat, had a persistent stomach ache, and was
vomiting blood. When O'Hara X-rayed the boy again, she saw a perforated, "moth-eaten
disc" with irregular edges that looked "like something had been nibbling on it." Suspecting
it was a piece from some toy, she had another doctor remove it with a tool inserted down
the child's throat.
To her shock, what emerged was the penny. She says, "You could just make out the
date, 1989, on what was left."
"We had always thought pennies were innocuous visitors [to a child's gastrointestinal
tract]," O'Hara explains. However, after 4 days in a child's stomach, this penny had lost
one-quarter of its weight, developed dangerously ragged edges, and induced an ulcer in
the stomach lining.
Though most pennies will pass through a child safely, O'Hara has since encountered a
second eroding penny.
Pennies were once 95 percent copper and relatively inert. In 1982, however, the U.S.
Mint began stamping pennies out of zinc coated with a thin veneer of copper. O'Hara
suspects that through normal wear and tear, this copper skin can crack, allowing the
stomach's hydrochloric acid to dissolve some of the zinc into a toxic, ulcerating soup. She
notes that other U.S. coins, made mostly of nickel, pose no similar risk. —J. Raloff
A 1989 penny after 4 days in a child's stomach.
Preemie diets linked to IQ
What a premature infant eats in the first month of life can have lasting intellectual impact
—at least in boys—a new study finds.
In the early 1980s, researchers at the Medical Research Council (MRC) in London
randomly assigned more than 400 preterm babies born in Norwich and Sheffield, England,
to receive either a standard infant formula or one that MRC had designed to meet a
preemie's unusually high nutritional demands. At that time, special preemie formulas were
just being developed. The special feeding lasted until an infant reached 4.4 lb or left the
hospital, so most babies ingested the formula for only 4 weeks.
In the Nov. 28 British Medical Journal, Alan Lucas and his colleagues at MRC report IQ
scores for the two groups of formula-fed children, tested when they were about 8 years
old. While girls from the two groups performed about equally, boys from the preemie-
formula group scored an average of 12 points higher on verbal tests than boys who had
received standard formula. Animal data have shown that males exhibit a heightened
vulnerablity to effects of neonatal malnutrition on learning and behavior, Lucas' team says.
Cerebral palsy also was much less common among infants getting the MRC-designed
formula. Today, most preemies are fed such a special formula. —J. Raloff
Very Large Telescope: New infrared camera struts its stuff
These heavenly pictures show off the capability of a sensitive infrared camera, installed
Nov. 14 on the first of what will eventually be a quartet of 8.2-meter telescopes on Cerro
Paranal mountain in Chile. The first of four instruments, collectively known as the Very
Large Telescope, began operation in May. The last is scheduled to be completed in 2001.
The telescopes will be able to work independently and as one large instrument.
The image on the left homes in on the galaxy cluster CL2244-02, a few billion light-
years from Earth. In this near-infrared and visible-light composite, the central, blue-green
arc represents a more distant galaxy, whose light has been bent by the gravity of the
massive cluster. The red arc (arrow) was detected only in the infrared and probably
indicates bent light from an even more distant galaxy.
The other image, a composite of three near-infrared pictures, shows the Milky Way star-
forming region RCW38, some 5,000 light-years from Earth. In visible light, these young
stars are hidden from view by the clouds of gas and dust in which they were born. The
European Southern Observatory released the images Nov. 26. —R.
Cowen
Scientists harvest antibodies from plants
People may never look at a field of corn quite the same way again. Several research
groups and biotech firms have genetically engineered corn and other plants to
manufacture valuable human proteins called monoclonal antibodies. The scientists hope
to cheaply mass-produce antibodies that can treat cancers, stem the spread of infectious
diseases, act as contraceptives, and even stop tooth decay.
Strengthening that prospect, two recent reports indicate that antibodies synthesized by
plants function normally in people and animals.
"Twenty years ago, monoclonal antibodies were supposed to be the magic bullets. We
think now is the time they're going to be those magic bullets," says Kevin J. Whaley of
Johns Hopkins University in Baltimore, Md., an author of one of the studies.
To combat infectious organisms, the human immune system makes a wide range of
antibodies, each one a protein that binds to a specific molecular target. About 2 decades
ago, researchers learned how to transfer immune genes into microbes and animal cells,
allowing them to make limited amounts of a single desired antibody. Scientists envisioned
many uses for these monoclonal antibodies, such as homing in on cancer cells.
Yet the promise of monoclonal antibodies faded over the years. When scientists first
used mice to make monoclonal antibodies, for example, the human body rejected the
molecules. With further genetic engineering, immunologists have of late created more
humanized antibodies in mice, but the animals still can't synthesize adequate amounts.
Monoclonal antibodies, therefore, can cost hundreds of dollars per microgram.
In search of more prolific methods, several companies have genetically engineered
cows and goats to secrete antibodies into their milk. While that approach should lower
costs, there is concern that it may be difficult to separate the antibodies from any bacteria
or viruses in the milk.
"If we're going to begin using antibodies as either therapeutics or preventatives, we're
going to need massive amounts. From a cost-effectiveness standpoint, and safety of
production, plants look like the superior opportunity," says Charles J. Arntzen of Cornell
University.
Scientists calculate that plant-made antibodies will cost less than $10 a gram.
Moreover, plants don't have many pathogens that infect people, says Mich B. Hein of
EPIcyte Pharmaceuticals in San Diego.
When plants make antibodies within their cells, however, they decorate them with sugar
molecules—a process called glycosylation—in a manner different from that of human
cells. That had raised concerns that these "plantibodies" wouldn't work as effectively as
normal ones or that a mammalian immune system would perceive them as foreign.
In the December Nature Biotechnology, Whaley and his colleagues report that when an
antibody made in soy plants was applied to the vaginas of mice, it prevented infection by
the genital herpes virus.
Earlier this year, in the May Nature Medicine, Julian K-C. Ma of Guy's Hospital in
London and his colleagues described the first use of a plantibody in people. Made in
tobacco and applied to the teeth of volunteers, it prevented one of the bacterial infections
that leads to tooth decay.
Whaley and Hein are now working to make corn produce the antiherpes plantibodies, as
well as antibodies that prevent sperm from reaching an egg. The antibodies could lace
gels or other substances applied topically. Whaley argues that plants may be the only way
to produce antibodies inexpensively enough that they can be employed worldwide, even in
developing countries.
"The rest of the issues are not scientific. They're economic," agrees Hein. "We have to
demonstrate the cost-effectiveness of this method." —J. Travis
Objective Visions
Historians track the rise and times of scientific objectivity
By BRUCE BOWER
In an influential 1749 atlas of the human skeleton and muscles, Dutch anatomist
Bernhard Albinus describes his meticulous methods for bringing a particular specimen to
the printed page. Albinus carefully cleans, reassembles, and props up a complete male
skeleton; he checks the position of each bone in comparison with observations of an
extremely skinny man hired to stand naked next to the skeleton; he calculates the exact
spot at which an artist must sit to view the skeleton's proportions accurately; and he
covers engraving plates with cross-hatched grids so that images can be drawn square-by-
square and thus be reproduced more reliably.
The modern reader of Albinus' work then gets a shock. After all that excruciating
attention to detail, the eminent anatomist announces that his atlas portrays not a real
skeleton, but an idealized version. Albinus has dictated alterations to the artist. The
scrupulously assembled model is only a springboard for insights into a more "perfect"
representation of the human skeleton, visible only to someone with Albinus' anatomical
acumen.
It seemed perfectly reasonable for 18th-century knowledge seekers to defer to the
informed imaginations of acknowledged geniuses such as Albinus. Objectivity was not an
issue. That term did not acquire its current cachet in science until the 19th century. Then,
many scientists decided it was best to find ways to let nature speak for itself rather than
through the mouths of designated geniuses, says science historian Peter L. Galison of
Harvard University. Only recently, in historical terms, has science aspired to be based on
impartial treatment of physical objects, as opposed to subjective impressions.
Ever since science's embrace of objectivity, according to Galison and other historians,
the conceptual ground beneath the idea has shifted enough to give pause to anyone who
views it as a fixed vantage point from which successive scientific generations gaze upon
reality.
Historical analyses conducted in the past decade conclude that scientists' working
notions of objectivity and its usefulness have changed in significant and revealing ways.
External reality has remained a constant focus of inquiry, the historians emphasize, but
investigators frequently grapple with the daunting task of deciding which of its myriad
features merits special attention.
Enter objectivity. Historians view objective standards as a flexible framework for
reasoning about the world and communicating with large networks of peers in a chosen
field. Science's success and growth, combined with outside pressures to solve societal
problems and to justify research funding, have helped shape and transform this
framework.
The historians' efforts to study objectivity have great significance for what are called the
science wars. They revolve around clashing beliefs over what scientists can know about
the world. Combatants in that intellectual slugfest tend either not to know about work on
the history of objectivity or to view it with ambivalence, remarks Ian Hacking, a philosopher
of science at the University of Toronto. Hacking is familiar both with the historical analyses
and the ongoing bitter debate over the nature of science.
On one side of the battle stand scholars, including sociologists and philosophers, who
portray objective methods in science as products of a social consensus among
practitioners based on their shared assumptions about the nature of reality. Objectivity
then is a tool that scientists use to tell stories about how the world works and to boost their
power and prestige, according to advocates of this perspective.
Critics of this view respond that conventions of objectivity allow researchers to chip
away at chunks of reality that, with perseverance, yield basic laws of nature. Cultural and
personal philosophies may organize scientific approaches to a problem, but theories
grounded in real-world evidence eventually yield culturefree knowledge, in this view.
Science historians express frustration with what they see as a tendency of both sides in
this battle to treat objectivity as something locked in place, an indentured servant either of
personal and social interests or of external reality.
"The great debate about the desirability of objectivity in science is highly confused,"
says Lorraine Daston, director of the Max Planck Institute for the History of Science in
Berlin. "Objectivity has had and continues to have different meanings." Its modern
meanings include empirical reliability, procedural correctness, emotional detachment, and
absolute truth, she notes.
Adds Theodore M. Porter of the University of California, Los Angeles, "We need to
examine more closely the historical development of objectivity without making the exercise
an attack on science."
A good place to begin untangling the roots of objectivity is the scientific atlases that
proliferated from about 1830 to 1920, holds Galison. At that time, atlas makers embraced
a form of objectivity in which cameras and a host of other machines were seen as stages
on which nature could speak for itself without human prompting, he maintains. Atlases in
this tradition of "mechanical objectivity" covered a vast array of phenomena—fossils,
clouds, stars, elementary particles, bones, wounds, embryos, and plants, to name a few.
Inspiration for the new wave of atlases derived partly from growing unease with the
earlier scientific practice of Albinus and other supposedly inspired geniuses to fish out
"true forms" from beneath nature's surface. For instance, turn-of-the-century
paleontologists began to question their convention of drawing ideal versions of partial or
misshapen fossils, which were then used as centerpieces for evolutionary theories.
Around the same time, an increasing number of established scientific theories came
under attack or were discarded. Investigators started to doubt whether they possessed a
stable core of knowledge. Particularly stinging was the replacement of the Newtonian
theory of light with the wave theory championed by French physicist Augustin Fresnel.
Scientists of the 19th century rapidly adopted a new generation of devices that rendered
images in an automatic fashion. For instance, the boxy contraption known as the camera
obscura projected images of a specimen, such as a bone or a plant, onto a surface where
a researcher could trace its form onto a piece of paper. Photography soon took over and
further diminished human involvement in image-making. In a joint article published in the
Fall 1992 Representations, Galison and Daston documented the rise of mechanical
objectivity in scientific atlases.
Researchers explicitly equated the mechanical registration of items in the natural world
with a moral code of self-restraint, Galison and Daston hold. A blurry photograph of a star
or ragged edges on a slide of tumor tissue were deemed preferable to tidy, idealized
portraits.
A saintly struggle against the temptations of interpreting and improving what one
observed was a kind of purifying ritual for scientists, readying them to receive natural
truths, the two historians suggest.
Astronomer Percival Lowell's effort at the start of the 20th century to establish the reality
of canals on Mars starkly illustrates this point, according to Galison. Lowell took great care
in sketching his initial telescopic discoveries. After observing more features of the Martian
landscape, Lowell described in his journal how he refused to add these characteristics to
earlier drawings because he wanted to ensure scientific objectivity and guard against
unintentional "artistic delineations."
Lowell also agreed with book editors to refrain from a judicious retouching of his blurry,
gray photographs of the Red Planet, which would have made Mars' canals visible in
published reproductions. Such embellishments would invite claims that "the results were
from the brain of the retoucher," Lowell's editors wrote to him in 1905. So, readers of his
book were left to squint at a hazy version of the scientist's hard-won images.
Daston and Galison each emphasize different implications for science in the rise of
mechanical objectivity. In the Winter 1998 Daedalus, Daston contends that this brand of
objectivity accompanied broader cultural changes in Europe that polarized artists and
scientists. Her article's title describes what she sees as the result: "Fear and Loathing of
the Imagination in Science."
In the 18th century, imagination was viewed as essential to philosophy and science as
well as to the arts, Daston says. Moreover, facts were assumed to arise out of particular
observations or experiments and were subject to later revisions.
Romantic poets, writers, and artists of the 19th century claimed imagination as their
inner muse, calling it an unexplainable creative impulse residing within the individual.
Scientists, on the other hand, broadened their pursuit of objectivity beyond its basic
mechanical form, in Daston's opinion.
Researchers began to standardize their instruments, clarify basic concepts, and write in
an impersonal style so that their peers in other countries and even in future centuries
could understand them.
Enlightenment-influenced scholars thus came to regard facts no longer as malleable
observations but as unbreakable nuggets of reality. Imagination represented a dangerous,
wild force that substituted personal fantasies for a sober, objective grasp of nature.
Scientists then and now acknowledge the presence of imagination in their work,
particularly in devising ground-breaking theories and experiments, Daston notes. She
suspects, however, that mainstream researchers experience a complex mix of admiration,
envy, and disdain for the relatively few creative pioneers in their midst.
Galison, however, says that by around 1920, mechanical objectivity gave way to an
emphasis on a kind of trained imagination in medical and natural sciences. Many atlas
makers in these fields chose images that, in their opinion, brought into relief crucial
elements that would help the observant reader learn how to interpret such displays with an
expert eye, he suggests in Picturing Science, Producing Art (1998, Caroline A. Jones and
P.L. Galison, eds., Routledge).
In this approach, subjective impressions got a reprieve. However, they were assumed to
work in favor of all experienced practitioners and researchers rather than simply a few
geniuses.
A 1941 atlas of electroencephalograph, or brain-wave, readings provides an example of
how informed judgment replaced mechanical objectivity, Galison asserts. The authors
wrote that they used their many years of experience to select EEG waveforms that would
best help novices notice key patterns and train themselves to reach accurate diagnoses at
a glance, such as distinguishing between the wave output of a person with epilepsy and
one without epilepsy.
Nonetheless, scientists of all stripes still find much of value in a facet of mechanical
objectivity that emphasizes the impartial application of standard mathematical methods,
says Porter. Quantitative rigor proves most alluring to troubled scientific communities,
which are buffeted by internal divisions and outside criticisms, he argues. Objective
standards attempt to heal the distrust among researchers who are largely strangers to one
another by making their specialized knowledge public and impersonal.
In contrast, and perhaps somewhat surprisingly, disciplines that enjoy a more secure
status operate largely on the basis of informal, shared conventions rather than rigidly
applied objective methods.
Porter explored several examples of this pattern in his book Trust In Numbers (1995,
Princeton University Press). For instance, mathematically precise cost-benefit analyses
were developed in the early 20th century by the U.S. Army Corps of Engineers. In the face
of intense political pressure, the corps had been plagued by "utter disunity and savage
infighting," Porter says. At the same time, powerful congressmen opposed the corps'
efforts to plan and carry out major public works projects.
Analysis of congressional testimony, internal corps documents, and other sources
indicates that strict cost-benefit formulas expressed in mathematically objective terms,
such as those in the 1936 Flood Control Act, were developed by the corps to unite warring
engineers and to overcome legislators' concerns about its competence to carry out
complex tasks.
Yet, at the same time, the French government's engineering corps successfully resolved
controversies over the location and costs of various public works without conducting a
single cost-benefit analysis. Unlike their U.S. counterparts, the French engineers reached
consensus on thorny issues through informal discussions informed by their past
professional experiences. French politicians left the engineers alone, regarding them as
elite and eminently trustworthy products of the national educational system.
Members of France's engineering corps showed no interest in cost-benefit rules until
after World War II, when U.S. influence expanded in Europe, Porter contends.
Today, the small community of experimental high-energy physicists operates much in
the tradition of France's prewar engineers, in his view. These scientists—a select few who
survive a long process of formal training and research apprenticeships—have access to
only a few particle accelerators and constantly adjust or even completely rebuild their own
detectors for new experiments. Independent replication of experimental results proves
extremely difficult when the equipment constantly changes from one researcher to
another. Instead, influential physicists assess the skill and trustworthiness of
experimenters and reach agreement as to whether a particular set of findings merits
acceptance.
In contrast, experimental psychology, which faces stark internal divisions and
considerable political pressures, clings to rigid statistical formulas of objectivity (SN:
6/7/97, p. 356), the UCLA researcher holds.
Historical work like Porter's challenges the widespread tendency to treat objectivity as
"a given" that never changes, comments Hacking.
"Scientists employ techniques and ways of thinking which are powerful and effective,
but which are often hard to articulate," Porter says. "In science, as in political and
administrative affairs, objectivity has more to do with the exclusion of personal judgment
and the struggle against subjectivity than with truth to nature." n
In 1849, just before the flowering of scientific objectivity, botanist Joseph Hooker
directed the drawing of this plant, based on observations of several blossoms. He chose
to present what he saw as Rhododendron argentum's characteristic features.
Star motions yield four more planets
The hunt for planets outside our solar system continues to show results. The latest
findings include a nearby, sunlike star that may have two companions: a planet and a
heavier object, known as a brown dwarf. Studies also suggest that three other nearby
stars have closely orbiting planets, bringing to 16 the number of extrasolar planets that
astronomers have indirectly detected around sunlike stars. As recently as August, only 10
such planets had been identified (SN: 8/8/98, p. 88).
The main search strategy has stayed the same since the first extrasolar planet was
discovered in 1992. By tracking the back-and-forth motion of nearby stars toward and
away from Earth, astronomers infer the gravitational tug of planets too faint to be detected
directly. This technique favors the detection of massive, closely orbiting planets, since
these bodies induce the largest wobbles in their parent stars.
Researchers have identified two planets among a sample of 82 stars they had begun
monitoring recently at Lick Observatory on Mt. Hamilton in California. The team had
already been studying 107 stars at Lick for several years. One of the newly found planets,
which orbits the sunlike star HD195019, is at least 3.51 times as massive as Jupiter and
whips around the star in just 18.27 days.
The other planet found at Lick Observatory circles the sunlike star HD217107 once
every 7.12 days and is at least 1.27 times as massive as Jupiter. Geoffrey W. Marcy of
San Francisco State University and the University of California, Berkeley and his
colleagues, including R. Paul Butler of the Anglo-Australian Observatory in Epping,
Australia, will report both Lick findings in the January 1999 Publications of the
Astronomical Society of the Pacific.
A third discovery, which Marcy announced Dec. 2, during a talk at Marymount College
in Palos Verdes, Calif., concerns a star whose motion was tracked at the W.M. Keck
Observatory atop Hawaii's Mauna Kea. The wobble of the star HD168443 suggests that it
has a planet, which is at least 4.96 times as massive as Jupiter, in a highly elongated
orbit.
The tug of a single object can't fully explain the star's motion, however. Marcy proposes
that the star has another companion—either a tiny star or a brown dwarf, an object
heavier than a planet but too lightweight to shine continuously as stars do.
The fourth find comes from a Swiss team working at the European Southern
Observatory's La Silla Observatory in La Serena, Chile. Using a new telescope and
spectrograph devoted to tracking stellar wobbles, the team found evidence of a planet
circling Gliese 86, a dwarf star with a mass 0.79 times that of the sun. About 35 light-years
from Earth, this is the second-closest star known to harbor a planet.
Gliese 86 has another distinction: It possesses an unseen stellar partner. The
separation between the two stars is probably more than 100 times larger than the distance
between the newly discovered planet and the star it orbits, the Swiss team reports. The
planet circles the star once every 15.83 days and is at least 4.9 times as massive as
Jupiter. It is separated from its parent by just over one-tenth the distance between the sun
and Earth. Didier Queloz of the Geneva Observatory and NASA's Jet Propulsion
Laboratory in Pasadena, Calif., and his colleagues announced the finding on Nov. 24.
—R.C.
The new Leonard Euler Telescope at La Silla Observatory.
Fill 'Er Up . . . With Veggie Oil
Vegetable oils are moving
from the kitchen table
to the car engine
By CORINNA WU
Oil from plants—such as these sunflowers growing in a field near Davis, Calif.—can
serve as an environmentally friendly substitute for petroleumbased products.
Asked to name a striking image from the 1970s, some might think of President Nixon
making his resignation speech, a news photo from the Vietnam War, or even a young
John Travolta striking a pose.
Others might recall the long lines of cars at gas stations during the oil embargo. From
October 1973 to March 1974, Arab nations banned oil exports to the United States in
retaliation for U.S. support of Israel during the Arab-Israeli War. Gasoline became a rare
and precious commodity.
Those lean days made it all too clear how heavily the United States had come to
depend on imported petroleum and how easily its supply could be cut off. The energy
crisis of the 1970s, followed by high oil prices in the early 1980s, sparked widespread
interest in alternative energy sources.
Today, gasoline is again plentiful and cheap, and the long lines at gas stations are a
fading memory. Research into alternatives, however, continues. Some geologists predict
that petroleum production will peak within 2 decades, then diminish, triggering a sharp rise
in oil prices (SN: 10/31/98, p. 278).
Hoping to develop technologies that could lessen U.S. dependence on imported oil,
some scientists are looking to a homegrown solution, literally. They are developing diesel
fuels and lubricants based on vegetable oils—the same vegetable oils that people drizzle
on
salads and use to cook french fries.
Oils from soybeans, corn, canola, and
sunflowers all have the potential to move from the kitchen to the garage, researchers
say.
In some applications, fuels and lubricants made from vegetable oils actually perform
better and pollute less than their petroleum counterparts. Their big drawback, however, is
that they're two to three times more expensive. For that reason, researchers are adapting
vegetable oil for those fuel markets where its advantages might justify its cost.
The idea of using vegetable-based products as fuel is not new. German engineer Rudolf
Diesel reportedly employed peanut oil to power one of his engines at the Paris Exposition
of 1900. In the late 1970s, petroleum makers stretched limited fuel supplies by mixing
gasoline with ethanol from fermented corn. This formed a cleaner-burning concoction
known as gasohol (SN: 10/29/77, p. 280) that is still available. Gasohol burns more
completely than petroleum, producing less carbon monoxide and hydrocarbons.
To some researchers, vegetable oils seem like a natural choice for an alternative fuel
since the United States grows an abundance of agricultural crops. In Europe, strict
environmental regulations have made vegetable oilbased products an even more
attractive choice, since they present less of a problem if accidentally spilled. Seventy to 80
percent of a vegetable oil biodegrades to small organic molecules, carbon dioxide, and
water in standardized tests compared with only 20 to 40 percent of a conventional
lubricant, says André L. Boehman of the Pennsylvania State University in State College.
In a junkyard, a car leaking canola oil won't contaminate the soil as badly as one leaking
conventional gasoline or oil. A boat that inadvertently dumps soybean-based diesel fuel
into a lake won't foul the water as much as one releasing regular fuel.
Farmers also look to the oil research as a way to increase the market for their crops,
says Lowell Norland, director of community and business services for the Ag-Based
Industrial Lubricants Research Program at the University of Northern Iowa in Waverly.
Toward this goal, scientists in the oil research group at the Department of Agriculture's
National Center for Agricultural Utilization Research (NCAUR) in Peoria, Ill., are studying
the properties of biodiesel, a type of fuel derived from vegetable oil. It may someday serve
as an alternative to the diesel fuel used in many trucks and boats.
Ordinary diesel fuel is a mixture of hydrocarbon molecules of differing lengths and
structures. These molecules contain no oxygen atoms. Some hydrocarbons consist of
long, straight carbon chains; others branch like a tree or form rings. They may have
double-bonded carbons that cause the chains to bend. The characteristics of the
hydrocarbons affect how they burn.
Vegetable oils, on the other hand, are mixtures of fatty acids—molecules that contain
carbon, hydrogen, and oxygen atoms. The fatty acids may be saturated,
monounsaturated, or polyunsaturated, meaning they contain zero, one, or multiple double
bonds between carbons, respectively. The greater the number of double bonds, the more
easily the compound reacts with oxygen from the air and goes bad, as kitchen fats and
oils do after months on the shelf.
Saturated fats, such as those in lard, have another disadvantage as a fuel or lubricant.
They turn solid at low temperatures, while mono- and polyunsaturated oils remain liquid.
Researchers have their eye on polyunsaturated soybean oil, in particular, because many
of its properties, such as viscosity and combustibility, are similar to those of petroleum-
based oils.
To produce biodiesel, chemists treat a vegetable oil in a process called
transesterification. This turns the oil into methyl ester compounds, which burn more
cleanly than diesel fuel and leave fewer engine deposits than untreated vegetable oil.
When burned in an engine, biodiesel emits smaller amounts of pollutants, including
particulates, volatile organic compounds, carbon dioxide, and polyaromatic hydrocarbons,
than regular diesel fuel does, says Gerhard Knothe, a scientist at NCAUR. Notable
exceptions are the nitrogen oxides, major contributors to smog, which biodiesel generates
more of than does petroleum diesel.
On the other hand, biodiesel contains no sulfur, unlike regular diesel, so acid-rain-
producing sulfur oxides aren't a problem (SN: 8/27/94, p. 134).
"You can smell the difference," Knothe observes. "The fumes from biodiesel are less
obnoxious."
An advantage of biodiesel over other alternatives to petroleum is that it works in existing
diesel engines. Other clean-burning fuels such as natural gas have combustion properties
so different from those of diesel fuel that they can't be used in conventional engines.
Natural gas must also be stored differently. "The fuel [itself] may be cheaper, but the
engine and infrastructure changes are so expensive, they outweigh that advantage," says
Knothe.
In terms of performance, however, biodiesel isn't yet up to par. Because of its
unsaturated fatty compounds, vegetable oil reacts with oxygen more easily than diesel
does, and so its properties can change. Biodiesel can also leave more gummy deposits in
engines than regular diesel does.
And just like cooking oil placed in the freezer, biodiesel thickens and forms solid crystals
—mostly of saturated fats—at low temperatures, plugging fuel lines. At 0°C, components
of biodiesel begin to crystallize. Lower the temperature a few degrees more, and the fuel
no longer flows. "Here in the Midwest, we'd be in trouble," says Knothe.
The fix is rather simple: The scientists can winterize the fuel by cooling it until the
crystals form, then filtering them out. The resulting biodiesel can start an engine at 15°C, a
temperature comparable to petroleum-based diesel.
Some of the fats filtered out, such as methyl palmitate and methyl stearate, tend to have
the best combustion properties, however. "It's a tradeoff," says Knothe. "You improve one
property, but you have to be careful about the other."
Biodiesel can be combined with conventional diesel fuels, says Knothe. Several
companies manufacture a blend known as B20 because it contains 20 percent biodiesel
and 80 percent regular diesel fuel.
Biodiesel improves the slipperiness, or lubricity, of diesel fuel. When sulfur is removed
during refining of conventional diesel, the lubricity goes down. "If you add [biodiesel] in,
you get the lubricity back," says Knothe. As an additive to a fuel tank, biodiesel could
potentially reduce wear on moving engine parts.
In a similar way, vegetable oil added to an engine's oil pan can do the duty of motor oil
while polluting less. Boehman, Joseph M. Perez, and their colleagues at Penn State are
studying an engine lubricant made from sunflowers genetically modified to produce oil with
a high concentration of monounsaturated oleic acid. To test a formula made by
Renewable Lubricants in Hartville, Ohio, they compared it with a 10W-30 petroleum-based
oil.
In the lab, Boehman explains, he puts lubricant in a small diesel engine, which he runs
at a variety of temperatures and engine speeds. He passes the exhaust through a filter
and collects particles of soot and other pollutants.
The researchers see a reduction in particle emissions with the sunflower oil, although
they want to confirm those results with additional tests, says Boehman. He presented
some of the group's recent findings in August at a Boston meeting of the American
Chemical Society.
In regular engine operations, "most of the emissions come from the lubricant," he says.
Oil vapors that don't get burned condense on the solid particles of soot that fly out through
the exhaust pipe. Vegetable oil doesn't evaporate as easily as petroleum-based oil, so
less finds its way out of the engine.
Because oleic acid has only one double bond, it doesn't react with oxygen as readily as
polyunsaturated oils do. Adding antioxidants to sunflower oil improves its stability, to
resemble that of 10W-30 motor oil.
As foods, monounsaturated oils such as olive and canola oil may have health benefits
(SN: 11/21/98, p. 328). Therefore, many agricultural seed companies are genetically
modifying plants to increase their proportion of monounsaturated oils, says Norland. "What
seed companies are developing for human consumption is also very good for industrial
lubricants."
If vegetable oilbased fuels and lubricants are to compete with conventional ones, their
price will have to drop considerably.
"Biodiesel will not be able to replace all conventional diesel," says Knothe. "If you took
all the vegetable oil in the world and made biodiesel out of it, you'd only replace a few
percent of the whole conventional diesel market. That's the reason why the National
Biodiesel Board [a trade organization] is targeting niche markets." These markets would
include urban bus fleets, mining equipment, and marine vessels. Mine and marine
environments face particular threats from fuel spills.
One factor that would reduce the price is an increase in supply spurred by changing
patterns of consumption, Norland suggests. Soybean products, for example, are gaining
recognition for their heart-healthy qualities (SN: 5/30/98, p. 348). "As soybean flour is used
more and more, oil becomes a by-product," he notes.
Legislative activity may drive the acceptance of vegetable oilbased fuels and lubricants,
whatever their price. The omnibus spending bill recently passed by Congress recognizes
B20 as an alternative fuel. The Clean Air Act of 1990 and the Energy Policy Act of 1992
also create markets for these products.
In Germany's Black Forest region, environmental protection laws require farm
machinery to use only biodegradable fuels and lubricants, thereby instituting "almost a
requirement to use veggie oil," says Boehman. Several products based on canola oil are
used in Europe.
At the University of Northern Iowa, Lou Honary and his colleagues developed a
vegetable oil replacement for hydraulic fluid used in heavy machinery such as forklifts and
garbage trucks. An Iowa bill passed this year requires all state agencies to purchase as
much of this fluid, called BioSOY, as allowed by their budgets and manufacturer
warranties on equipment.
Oil companies themselves don't see vegetable-based products as a threat, according to
Honary. Instead, they have already jumped on the bandwagon. "I don't know of any
petroleum company that doesn't have a green program running," he says. "They are all
trying to find some way to promote the use of vegetable oils. They'd like to have this
alternative for certain applications."
In the end, researchers hope that vegetable oils will perform well enough to convince
people to use them. Honary looks to the example of Sandia National Laboratories in
Albuquerque, N.M. The facility tested BioSOY in 20 of its own vehicles from 1996 to 1997.
This hydraulic fluid worked so well that Sandia decided to use it in all of its vehicles. n
Legislative activity may drive the
acceptance of
vegetable oilbased fuels and lubricants, whatever their price
Iowa lawmakers are encouraging state agencies to use BioSOY, a hydraulic fluid made
from soybean oil, in vehicles and heavy machinery.
Biodiesel fuel made from processed soybean oil emits fewer pollutants when burned
and is less harmful to the environment if accidentally spilled.
Biology
Geraniums intoxicate Japanese beetles
Several bites of a garden-variety geranium, and a Japanese beetle falls to the ground in
a stupor that lasts some 8 hours. It's hardly a great way to avoid predators or get on with
beetle business, like reproduction. Yet researchers now find that the beetles never learn.
They choose geraniums over perfectly good linden leaves and get paralyzed day after
day.
Researchers described the knockout effect on Japanese beetles in 1929, notes Daniel
A. Potter. He and David W. Held, both of the University of Kentucky in Lexington, have
studied beetle learning and the sad effects of geranium intoxication on family life. Their
results will appear in an upcoming issue of the journal Entomologia Experimentalis et
Applicata.
In theory, insects with wide-ranging tastes are the most likely to learn to avoid noxious
foods, according to the few studies that have tested this idea, Potter says. However,
Japanese beetles eat nearly 300 U.S. plant species but don't avoid geraniums.
The flower petals, especially from plants in full sunlight, seem the most narcotic, Potter
reports. His most extensive tests were of red geraniums, but flowers of white, coral, and
other colors also slammed the beetles. So did a water-soluble leaf extract.
A geranium "is like candy to them," Potter says. Beetle pairs offered a choice picked
geranium flowers so often that they laid just half as many eggs as pairs provided only with
linden leaves. Intoxication is dangerous for the beetle, but is it fun? Potter won't speculate.
—S.M.
Ravens' memories can lead to thievery
Ravens not only remember where they hid their own food; there's evidence they
remember—and steal—caches of other ravens.
As far as Bernd Heinrich is aware, his raven studies at the University of Vermont in
Burlington are the first to show that a bird's memory for caches extends to somebody
else's hoard.
Ravens don't just sniff out hidden meat, report Heinrich and John W. Pepper of the
University of Michigan in Ann Arbor. When Heinrich, unseen by the birds, hid 40 caches in
snow in a large, outdoor aviary, the ravens failed to find even one.
Yet when nine ravens hid food at the same time and looked for it the next day, they
found 58 out of 85 caches. Fifteen of these were thefts. The ravens appeared to search
deliberately in specific spots, Heinrich says. He has also observed that a raven changes
its hiding strategies, going farther to stash booty, if others are watching. Results appear in
the November Animal Behaviour. —S.M.
Diverse fungi underlie plant success
There's a hidden side to plant diversity that people had better start paying attention to,
warn two research teams.
Their experiments demonstrate the major importance of soil fungi in shaping plant
communities, say Marcel G.A. van der Heijden of the University of Basel in Switzerland,
John N. Klironomos of the University of Guelph in Ontario, and their colleagues. Yet the
possible loss of diversity in soil fungi has hardly been studied, they lament in the Nov. 5
Nature.
Most soils have so-called arbuscular mycorrhizal fungi, which grip roots and boost
nutrients for an estimated 80 percent of land plant species. A forest might have 30 of
these fungal species, but crop fields typically have few, Klironomos says.
The Swiss researchers grew greenhouse pots of 11 plants with different soil fungi. Plant
growth varied depending on the fungus. "This was a surprise," Klironomos notes.
Researchers had assumed that any of the fungi could partner with any plant.
Outdoors, Klironomos' group seeded each of 70 tubs with the same combination of 15
plants but different fungi, from a lone species to a mix of 14. All the plants sprouted, but in
some tubs, a few species took over. Plant communities were most diverse in tubs with
eight or more fungal species. —S.M.
Behavior
Schizophrenia: Consenting adults . . .
Apathy, hallucinations, inappropriate emotions, and confused or paranoid thoughts rank
among the central symptoms of schizophrenia. Nonetheless, a new study suggests that
determined investigators can help people suffering from this disorder discern the pros and
cons of participating in research.
Scientists and clinicians have raised concerns about the ability of individuals with
severe psychiatric conditions to grasp the risks and benefits of research projects they're
asked to take part in. For example, up to one-half of hospitalized patients with
schizophrenia and one-quarter of those with major depression exhibit markedly impaired
judgment in interviews conducted shortly after their admission (SN: 1/7/95, p. 8).
Schizophrenia sufferers, however, understand and remember much about proposed
clinical trials after exposure to thorough procedures for gaining their "informed consent,"
contends a research team led by psychiatrist Donna A. Wirshing of the West Los Angeles
Veterans Affairs Medical Center.
The researchers recruited 49 psychiatric patients diagnosed with schizophrenia who
were already participating in ongoing trials of several antipsychotic medications. An
experimenter first read to each patient an informed-consent document concerning an
upcoming randomized clinical trial. A researcher then administered a survey that
Wirshing's team devised to gauge how well volunteers understood what they had heard.
Surveys probed for knowledge about the study's procedures and goals, patients'
available choices as participants, their physicians' responsibilities to the investigation, and
potential ill effects of antipsychotic drugs that were to be given in the trial.
Five patients answered all survey questions correctly on an initial test. For the rest, a
researcher immediately explained any items that were answered incorrectly and
administered the survey again. Another 26 patients correctly answered all questions on a
second try, and 18 did so after three or more attempts.
One week later, all the volunteers still answered most survey items correctly, the
scientists report in the November American Journal of Psychiatry. This finding held even
for patients displaying the most severe thought disturbances and hallucinations.
In an accompanying editorial, psychiatrist Paul S. Appelbaum of the University of
Massachusetts Medical School in Worcester remarks that other tactics to boost psychiatric
patients' capacity to consent to research should also be explored. These include involving
family members in the teaching process and using instructional videotapes, he says. —
B.B.
. . . and memory lapses
Schizophrenia is often marked by poor performance on memory tests, accompanied by
diminished activity in frontal brain areas involved in reasoning. It's unclear, however,
whether these mental lapses tap into a neural disturbance specific to the disorder or
reflect the unwillingness of frequently apathetic schizophrenia sufferers to make the
mental effort to remember. A study directed by neuroscientist Paul C. Fletcher of the
Institute of Neurology in London lends support to the latter view.
Twelve people with schizophrenia and seven adults with no psychiatric ailments
underwent positron emission tomography (PET) scanning as they learned and recalled
lists of 1 to 12 words. PET scans yield measures of blood-flow changes in the brain, an
indirect sign of mental activity.
In schizophrenia, frontal brain activity and memory performance dropped as tasks
became more demanding, consistent with a lack of mental effort, Fletcher's group reports
in the November Archives of General Psychiatry. In contrast, the researchers found,
frontal activity rose in the mentally healthy adults as they successfully recalled more
information on progressively more challenging tasks. —B.B.
Biology
From Los Angeles at the annual meeting of the Society for Neuroscience
Voles are addicted to love
It's said that love is a drug. In a rodent species, scientists may now have proof. They've
collected evidence that love, or more accurately, the choice of a mate, stimulates the brain
in the same way as do drugs such as cocaine and heroin. "This type of social attachment
uses the same reward pathway," says Thomas R. Insel of Emory University in Atlanta.
For many years, Insel has examined the brain chemistry behind the monogamy of one
strain of voles (SN: 11/27/93, p. 360). When these rodents mate, their brains release
chemicals that prompt the animals to form enduring partnerships. In females, it's a
compound called oxytocin that drives the vole's attachment to a partner. In fact, injections
of oxytocin into the brain of a female vole can duplicate the effects of mating and induce
pair bonding. Drugs blocking oxytocin's action prevent females from pairing with males
after mating.
Hoping to explain oxytocin's effects, Insel and his colleagues Brenden S. Gingrich and
Carissa Cascio have studied the role of another brain chemical, the neurotransmitter
dopamine. Recent research indicates that the addictive nature of many drugs, including
nicotine, depends on dopamine. The drugs' pleasant sensations are stimulated by the
neurotransmitter's release within a brain region called the nucleus accumbens (SN:
7/20/96, p. 38). Over time, the brain appears to become more and more dependent on this
dopamine, causing people to crave the drugs.
Insel's group has now found that this reward mechanism may drive the monogamy of
voles as well. Brain injections of dopaminelike drugs induce female voles to prefer a single
male, without mating, while dopamine-blocking agents inhibit the usual bonding that
occurs after mating. The researchers also measured the natural production of the
neurotransmitter within the brains of female voles as they mated. Within the nucleus
accumbens of mating females, the scientists found dramatic dopamine increases, which
lasted for several hours.
Insel and his colleagues have discovered that brain cells in the nucleus accumbens
sport the cell-surface proteins that oxytocin activates. Blocking these receptors made it
less likely that female voles would pair after mating. From such evidence, the researchers
hypothesize that mating induces oxytocin production, which in turn stimulates the release
of dopamine. —J.T.
The threat of a piece of pumpkin pie
Some people with the eating disorder anorexia nervosa may have an actual fear of
food, according to a new study. Alan J. Strohmayer of the North Shore University Hospital
in Manhasset, N.Y., and his colleagues found that people with anorexia nervosa
experienced a stress response, detected by activation of their sweat glands, when simply
viewing photos of pizza, pasta, ice cream, and other foods. People with bulimia, who
deliberately vomit after eating, didn't react in the same way.
The researchers tested five women with anorexia nervosa and five with bulimia. On
average, sweat gland activity in those with anorexia nervosa increased by 52 percent
when they saw the images of a dozen different foods.
Many psychologists argue that anorexia nervosa stems from a fear of gaining weight,
which causes people to avoid eating and, in some cases, to starve themselves to death. A
food phobia, says Strohmayer, hasn't been considered before. It's not surprising that
people with bulimia don't share this phobia, since they don't refrain from eating, he adds.
Strohmayer notes that current psychological treatments for anorexia nervosa often
prove unsuccessful. He suggests that people with the eating disorder might be treated
with desensitization therapy. Patients would be gradually exposed to their phobia—food—
more often. This approach has worked for people with fears of flying and spiders, for
example. —J.T.