Death Maps'' Pinpoint Mortality Causes

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Often Preventable Deaths/Population

November 1, 2007—Africa appears to swell like a balloon when the world is mapped according to how many people died in 2002 due to diseases and other conditions that are largely preventable (top).

The continent appears much smaller by contrast in a map that sizes the countries of the world according to their shares of the human population (bottom).

These are just some of over a hundred "cartograms" released on October 19 by Worldmapper, a collaborative project spearheaded by researchers at the University of Sheffield in England and the University of Michigan. The maps use 2002 data from the World Health Organization's (WHO) Global Burden of Disease project to put a geographic twist on cause-of-death statistics.

Of the roughly 57 million people who died in 2002, more than 18 million succumbed to communicable diseases, complications from childbirth, or nutritional deficiencies, according to WHO. Worldmapper labels these deaths as "often preventable" because the conditions could have been easily treated with modern medicine.

The situation is "characteristic of populations that have not gone through the epidemiological transition to high life expectancy with most disease concentrated in older years," Colin Douglas Mathers, the WHO official responsible for the Global Burden of Disease data, said via email.

"Such populations, typically in India and Africa, are characterized by high infant and child mortality, high maternal mortality, and high levels of infectious diseases."

HIV/AIDS Deaths/Population

A Worldmapper cartogram highlights the high cost of HIV/AIDS in sub-Saharan Africa (top) compared to the continent's size when adjusted according to population (bottom).

In 2002 the region suffered about 80 percent of the 2.6 million deaths attributed to AIDS worldwide. This means that the disease, which goes largely untreated there, killed more than 6,000 Africans a day.

According to Worldmapper, the cartograms are akin to pie charts, except the slices of the pie are shaped into countries.

"I think that looking at a map rather than just the raw data allows you to see the whole picture and makes for easier comparison between the different datasets," Worldmapper's John Pritchard said in an email.

"We have plans for making more use of animations that morph one map to another … I think that this will be another useful tool in understanding the maps."

Lung Cancer Deaths/Population

A cartogram suggests that deaths due to lung cancer were highest in the United States, Europe, and Asia (top). That's because these countries appear much larger than they do compared to a similar map of global population (bottom).

Of the more than a hundred recognized cancers, lung cancer accounted for the most cancer-related deaths in 2002. A major cause was cigarette smoking, but exposure to dust containing asbestos, iron oxides, chromium, and radioactivity also played a part.

Globally, all known cancers accounted for 7,144,549—or about 12 percent—of the 57 million deaths in 2002.

Murders/Population

The number of murders (top) was significantly higher in South America and Africa, which appear to swell compared to a cartogram showing global population.

In 2002 murders accounted for 560,247 of the more than a million nonaccidental deaths worldwide—or roughly one percent of total deaths that year.

Suicides/Population

Asia suffers most of the world's suicide deaths, as seen in a cartogram showing the size of the world's countries adjusted for the number of self-inflicted deaths (top) compared to one based on global population (bottom).

Overall, WHO data suggest that individuals are more likely to kill themselves than they are to kill other people. Suicides accounted for 877,779 nonaccidental deaths worldwide—317,532 more than those attributed to murder.

War Deaths/Population

Data suggest that war deaths due both to direct combat and landmines hit hardest in Africa (top) when compared to a map depicting world population (bottom).

But experts with WHO note that casualties of war are especially difficult to tally.

"The estimates are based on a range of sources, primarily databases that collect reported deaths and, for some conflicts, surveys that have asked about deaths," Mathers said.

According to the best available data, war took the lives of 171,319 people—or 0.3 percent of all deaths—in 2002.

Strange but True: Whale Waste Is Extremely Valuable

April 26, 2007

According to the ancients, parfumeurs and Arab royalty, the old saying might as well go: "Worth its weight in whale waste"

By Cynthia Graber

	Image: © AMBERGRIS.CO.NZ
	VALUABLE JUNK: It may look like a rock weathered by the sea, but it is actually ambergris which, depending on age, can sell for thousands of dollars.

A ten-year-old vacationing in Wales stumbles across a lump worth nearly $6,000. A 67-year-old New York native receives a candlelike rock in the mail from her 80-year-old sister and discovers she may be $18,000 richer. All because a whale had a bit of indigestion.

That upset stomach creates ambergris, a rare substance that has been highly valued for thousands of years as an ingredient in perfume and pharmaceuticals. Ambergris originates in the intestines of male sperm whales after they dine on squid, whose hard, pointy beaks abrade the whales' innards. Scientists believe that the whales protect themselves by secreting a fatty substance in their intestines to surround the beaks. Eventually the animals cast out a huge lump, up to hundreds of pounds at a time.

But don't refer to it as "whale vomit"; scientists postulate that whales do not expel ambergris through their mouths. No one has ever seen a sperm whale excrete ambergris, although sperm whale expert Hal Whitehead of Dalhousie University in Halifax, Nova Scotia, admits that it is assumed the voiding takes place as fecal excretion, because when first cast out, he says, "Well, it smells more like the back end than the front."

Viscous, black, stinky blocks of freshly expelled ambergris float on the ocean's surface. Sun, air and salt water oxidize the mass, and water continually evaporates. It hardens, breaks into smaller chunks and eventually becomes grey and waxy, embedded with small black squid beaks. The weathered chunks exude a sweet, earthy aroma likened to tobacco, pine or mulch. The quality—and value—of any given chunk depend on how much time it had spent floating or otherwise aging, says expert ambergris broker Bernard Perrin, because "it ages like fine wine."

For thousands of years this sea treasure has been highly prized. Middle Easterners historically powdered and ingested it to increase strength and virility, combat heart and brain ailments, or to spice food and drink. The Chinese called it "dragon's spittle fragrance." Ancient Egyptians burned it as incense. A British medical treatise from the Middle Ages informs readers that ambergris can banish headaches, colds and epilepsy, among other ailments. And the Portuguese took over the Maldives in the sixteenth century in part to gain access to the island's rich bounty of the redolent stuff.

Image: © DENIS SCOTT/CORBIS
AMBERGRIS FACTORY: Because ambergris cannot be synthesized yet, sperm whales remain the only producers thanks to a diet heavy in sharp squid beaks.

The Arabic anbar refers to this very whale-based substance and is the root of the word amber. Centuries ago the French employed amber gris and amber jaune (gray amber and yellow amber) to distinguish between animal-based ambergris and what today has become the standard meaning: the golden-hued vegetal resin.

Like other animal-based perfume components (such as musk) ambergris has a scent all its own—derived from its chemical component ambrein—that it imparts to popular perfumes such as Chanel No. 5. It also enriches the other olfactory notes of a perfume, much as salt enhances flavors and spices, and, most importantly, it prolongs a perfume's other scents. As odor chemist George Preti of the Monell Chemical Senses Center in Philadelphia explains, ambergris molecules are lipophilic (fat-loving), as are perfume molecules, but the ambergris molecules are larger and heavier. "The odor molecules have a high affinity for the other lipophilic molecules, so they stay associated with the ambergris molecules and don't go into the vapor phase all at once," Preti says.

American perfume companies no longer mix ambergris into their fragrances, most likely because of confusing legalities surrounding its sale here. Internationally, however, the trade is legal and Perrin has no problem finding French perfume companies to buy his stock. "We also sell it to a royal family in the Middle East and they use it as an aphrodisiac. Apparently they take some milk, some honey, and grind up small quantities of the amber and put that in as well," he says.

Many aspects of ambergris remain a mystery. Why is ambergris more commonly found in the southern hemisphere, though sperm whales range all the world's seas? Why is it only sperm whales—and particularly male sperm whales—that create it? How did ancient Middle Easterners decide to start using it for medicine, or decide that "eau de whale" would be a compelling fragrance?

Some, but not all, scent qualities of ambergris have been synthesized, so the original remains valuable. With sperm whale numbers down from the 1.1 million estimated prior to whaling to approximately 350,000 today, less ambergris floats on the seas. Still, Whitehead says the population is slowly recovering, and even though most findings turn out to be rocks or wax or other ocean detritus, beachcombers and fishermen continue to scour the sands and waves in hope of stumbling across a weathered chunk of this sea gold.

Good Sex Is Not a Rat Race

By David Dobbs
For years the story on rat sex has been this: the male seeks above all else to ejaculate quickly, and once he has done it with one female, he is eager to move on to new partners. The female, meanwhile, seeks to extend the sex encounter through "pacing." A new study finds that if pacing is slow enough, the male will prefer that familiar partner to someone new. The wait, it seems, makes the female more attractive.

"It's an awful lot like what we were taught in high school," says Concordia University psychologist James Pfaus, who co-authored the study with Nafissa Ismail, the graduate student who conceived it.

The experiment made innovative use of standard research devices called pacing chambers, which are cages with dividers having either one or four holes big enough to let a female rat through but too small for the larger male. Thus, the female can join or leave the male, allowing her to significantly lengthen her arousal and, studies have shown, her chance of pregnancy. But the mating rituals last longer in the one-hole chambers, because the male, eager to get at the female, often sticks his big head in the hole, blocking her only passage back to his side and delaying her return.
The researchers let 20 couples mate in one-hole chambers and 20 in four-hole chambers. Then they placed each couple, along with a novel female, in a larger, open area. Among males from four-hole chambers, about half preferred their familiar mates. Among males who mated more slowly in the one-hole chambers, 80 percent preferred the familiar partner.

Driving this behavioral dynamic is, as always with rat sex, some neurochemical reward. Boston University biologist Mary Erskine notes that "sexual preferences come from chemical rewards, and we can be sure there are some here." Sexual climax, in fact, unleashes a flood of pleasure-producing hormones and neurotransmitters, such as testosterone and dopamine. Pfaus speculates that the higher level of arousal created by the longer wait generates a stronger release, and a more substantial reward, thereby enforcing the preference.

"Whether it's simply a stronger dose of the usual chemical rewards or some in addition, we don't know," Pfaus says. "But something is making this sort of mating more rewarding to the male or rewarding in a different way."

Brilliant Whiteness of Strange Beetle Explained

Forget bleach: this bug may be the key to whiter whites

By JR Minkel

Image: COURTESY OF PETE VUKUSIC/EXETER UNIVERSITY WHITE AS A BEETLE: An unusually white beetle sports a bright color despite having extremely thin scales compared with other white materials. Your walls, clothes and teeth not white enough for you? Good news: scientists have identified the source of the dazzling whiteness of a beetle called Cyphochilus, and harnessing that knowledge could help make everything from paints to t-shirts more blindingly white. It turns out that the bug's scales contain a porous network of random protein fibers that scatter all wavelengths of light strongly, the prerequisite for an intense white color. The beetle might not stand out against the brilliant blue of a butterfly, but "in terms of sheer design ingenuity, for me this is my favorite," says optical physicist Pete Vukusic of Exeter University in England, who has studied the bright coloring of dragonflies and butterflies.

Vukusic knew he was on to something when he saw Cyphochilus on an insect collector's Web site. "Something this amazingly bright and white had to be coming from something very thin," meaning its thin coat of scales, he says. "That in itself is quite interesting. Any industry can make something very white that's thick." The more layers a material has, he says, the stronger it can scatter light and the brighter its color can be. In this week's Science Vukusic and his colleagues report that the bug's five-micrometer-thick scales were whiter than a child's baby tooth, which is encased in a millimeter-thick layer of white enamel. They used an international standard to assess the beetle's relative whiteness. Electron microscopy revealed the scales are made of a tangle of seemingly randomly oriented filaments, each about 250 nanometers wide. A random microscopic structure is key to producing a white color, which results when all wavelengths of light scatter equally from a surface. If the surface contains any repeating pattern, it will reflect light of the wavelengths that match that pattern.

Image: COURTESY OF PETE VUKUSIC/EXETER UNIVERSITY WHITE STANDS OUT: White coloring is unusual in nature because it requires a surface to reflect all wavelengths of light strongly. To confirm the randomness of the filaments, the researchers took a cross-section image of the filament network and performed a mathematical technique called a Fourier transform, which reveals any repetition in a shape. They also shined a laser beam through one of the scales and projected the resulting pattern onto a curved surface. Any repetition in the scale's internal structure would show up in the pattern of projected light. Neither technique turned up any signs of nonrandomness, the group reports. Vukusic says the brightness of the color results from gaps of air between the filaments. Light scatters every time it passes between two materials that differ greatly in the speed of light through them, also called their refractive index. Like facets in a diamond, the more places light can scatter, the brighter the ultimate color. "If you separate the scattering centers, but not by too much, then you actually improve the efficiency at which the whole light spectrum is scattered," Vukusic says. If manufacturers can learn how to harness this effect, he says, they might be able to whiten just about anything that's white.

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The Incredible, Medical Egg

Genetically modified chickens that produce medicines in their eggs may be the drug factories of the future

By David Biello

Image: COURTESY OF ROSLIN INSTITUTE CHICKEN OR THE EGG: A genetically modified rooster has produced a flock of hens that make medicines inside the whites of their eggs. The chicken egg has a storied history in medicine. Even today, millions of ordinary fertilized eggs are each punctured with a drill and injected with flu virus to make vaccines. Now, scientists at the same research institute that cloned Dolly the sheep have produced a genetically modified rooster whose female descendants lay eggs that produce medicines in place of a protein in egg whites. Helen Sang of the Roslin Institute in Edinburgh, Scotland, and her colleagues used lentivirus to introduce a gene into freshly fertilized chicken embryos that trigger the production of various drugs rather than the protein ovalbumin, which normally makes up roughly 54 percent of egg whites. The researchers screened the resultant cockerels for one that produced the new gene in its semen. They then bred him with normal hens to produce a flock of chickens that carried the inserted gene thereby producing medicines in their egg's whites.

Tests of the flocks' eggs showed that they could produce either miR24--a monoclonal antibody used in treating melanoma--or interferon b-1a--an immune system protein used against multiple sclerosis, among other things--depending on which gene was inserted. The chickens produce 15 to 50 micrograms per milliliter of egg white, the researchers found, and though this is not as efficient as the expression of ovalbumin, it is efficient enough to allow for subsequent purification into therapeutic drugs. "We would expect the transgene not to be as efficient as the endogenous gene it was based on as only some of the regulatory elements were used and the transgene may be inserted in the chromosome at a position that does not favor anywhere near maximal expression," notes Roslin's Adrian Sherman, who also participated in the research. "I'm sure there is potential for improvement."

Chicken eggs may prove a better way to producepharmaceuticals than other genetically modified products (such as goat milk) that have been previously explored. Chickens are easy to raise, produce numerous eggs, and are cheap to keep. And, after raising five generations of the modified birds, the researchers have observed no adverse health effects, according to the paper published online January 15 in Proceedings of the National Academy of Sciences USA. Even though the therapeutic proteins worked as intended during in vitro assays, it will be years before the process is ready to be used to produce drugs for human consumption, researchers say. Roslin's chickens join a similar effort using stem cells developed by Origen Therapeutics. Regardless of which "biofactory" delivers drugs first, a new medicinal use for the venerable egg is now apparent.

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