As an annual salute to researchers who are "shaking up things" Popular Science magazine has named their "Brilliant 10" in the September issue including those in the fields of tissue engineering, molecular anthropology and cosmology. The University of Texas at Dallas professor Betty Pace was the only Texas researcher named to this year's list. Dr. Pace searches for gene triggers to quell the sickling mutation in those with sickle cell anemia.

To develop the list, the staff of the magazine spoke to university department heads, academic think tanks, the bestowers of awards. According to the article they were "looking for people who are causing a stir within their disciplines, the ones whose colleagues whisper about them with that special envy reserved for the halls of academe. You won't find a long list of their honors and publications here: The focus is on brilliant work being done and the vision for the road ahead."

The ten scientists named, by field, were:
-Computational Origami: Erik Demaine of MIT
-Cosmology: Xiahui Fan of the University of Arizona, Tucson
-Embedded Networks: Deborah Estrin of UCLA
-Genomics: Victor Velculescu of Johns Hopkins University
-Geophysics: Michael Manga of UC Berkeley
-Microfluidics: Stephen Quake of CalTech
-Molecular Anthropology: Sarah Tishkoff of the University of Maryland, College Park
-Molecular Medicine: Betty Pace of The University of Texas at Dallas
-Quantum Cryptography: Sae Woo Nam of the National Institute of Standards and Technology
-Tissue Engineering: Tejal Desai of Boston University

This year's epidemic of West Nile virus infection in humans appears to be outstripping last year's, a top federal health official said Thursday.

So far this season, 164 cases of the disease have been identified in 16 states, up from the tally at the same time last year of 112 cases in four states, the Centers for Disease Control and Prevention in Atlanta, Georgia, reports.

The CDC's tally of this year's reported cases, which have tripled in number since just last week, includes 72 from Colorado, 19 from Texas, 15 from Louisiana and several each in Alabama, Florida, Iowa, Kansas, Kentucky, Minnesota, Mississippi, Nebraska, New Mexico, North Dakota, Ohio, South Carolina and South Dakota. At least four people have died. Two died in Texas; the others in Colorado and Alabama,

But CDC was having a tough time keeping up with the quickly changing data: Colorado's Web site has posted a fourth West Nile death and 154 cases; Texas is reporting two deaths out of 28 cases.

Last year there were 4,156 cases of human infection, 284 of them fatal.

Colorado had reported no human cases of the disease at this time last year; so far this year it leads the nation. Coincidentally, the disease agency's center for the study of the West Nile virus is based in Fort Collins.

This year, the disease is also tending to affect younger people: the median age of infected people is 45, down from 55 last year.

All of this year's cases have been attributed to mosquito bites, although the virus could be transmitted via blood transfusions or organ donations. In July, the nation's blood banks began screening donations for West Nile.

There is no indication the epidemic has peaked. Last year, about two-thirds of new cases (65 percent) occurred in the six weeks after August 7.

Reprising last year's slogan, the CDC is urging people to "fight the bite" by taking steps to rid their yards of pools of standing water that could be used by mosquitoes as breeding grounds, to wear long-sleeved shirts and pants outside and to slather on insecticide containing DEET before going out.

The disease manifests in two primary forms: encephalitis, or swelling of the brain; and fever.

Last year's season extended through October.

West Nile virus is primarily transmitted by the bite of an infected mosquito. Most people who become infected have mild or no symptoms. According to the FDA, an estimated 1 in 150 people infected develop the more severe form of the disease.

Some kinds of hormone replacement therapy (HRT) have a much greater effect on a woman's risk of breast cancer than others, according to landmark research published in the Lancet this Saturday (August 9).

The Million Women Study, funded by Cancer Research UK, the NHS Breast Screening Program and the Medical Research Council, confirms that current and recent use of HRT increases a woman's chance of developing breast cancer and that the risk goes up with duration of use.

Current users of all types of HRT, including oestrogen-only, combined oestrogen-progestagen and tibolone, are at increased risk of breast cancer compared with women who have never used HRT. But the risk is substantially greater for users of combined preparations of HRT than for women on the other types.

Scientists at the Cancer Research UK Epidemiology Unit in Oxford analyzed data from over one million women between the ages of 50 and 64. Women joined the study between 1996 and 2001 and half were using HRT or had done so in the past. The study included 9,364 cases of invasive breast cancer and 637 breast cancer deaths, registered over 2.6 and 4.1 years of follow-up respectively.

Researchers found that post-menopausal women using combination HRT were twice as likely to develop breast cancer as non users (a 100 per cent increase), while risk increased by 45 per cent among users of tibolone and by 30 per cent among users of oestrogen-only HRT. These effects were shown to wear off within a few years of ceasing use.

In developed countries, among 1,000 postmenopausal women who do not use HRT, there will be about 20 breast cancer cases between the ages of 50 and 60.

For every thousand postmenopausal women who begin 10 years of HRT use at age 50, there will be five extra cases of breast cancer among users of oestrogen-only HRT and 19 among users of oestrogen-progestagen combinations. So combined HRT causes four times as many extra breast cancers as oestrogen-only.

The study also found that current users have a 22 per cent increased risk of death from breast cancer compared with women who have never used HRT, although the result was of borderline statistical significance. It is too early to estimate the number of extra deaths associated with HRT use.

Lead author Professor Valerie Beral, Director of the Cancer Research UK Epidemiology Unit, says: "We estimate that over the past decade use of HRT by UK women aged 50-64 has resulted in an extra 20,000 breast cancers, oestrogen-progestagen therapy accounting for 15,000 of these.

They recommended discussing treatment options with a doctor.

MIT researchers report in the Aug. 7 issue of Nature that they now understand how the insects known as water striders skim effortlessly across the surface of ponds and oceans.
In addition, the researchers created Robostrider, a mechanical water strider that uses the same fluid dynamics to move, although not as gracefully and quickly as its natural counterpart.

The hydrodynamics underlying the surface locomotion of these semiaquatic creatures (the family Gerridae and others) is poorly understood, said John W.M. Bush, associate professor of mathematics at MIT and author of the Nature study. In addition to water striders, he intends to apply his expertise in fluid dynamics to other surface swimmers.

Bush's water strider study solves a 1993 problem known as Denny's Paradox. It had been thought that water striders moved by creating waves that push them forward. Stanford University marine biologist Mark W. Denny pointed out that, theoretically, baby water striders could not swim because their legs weren't fast enough to create waves. But in fact, newly hatched water striders row across the surface just as well as adults.

Using mathematics, high-speed photography and a variety of flow visualization techniques, Bush, mathematics graduate student David L. Hu and mechanical engineering graduate student Brian Chan uncovered the true way in which water striders walk on water.

As the insect rests on the surface, the tips of its thin legs create miniscule valleys. It sculls the middle set of its three pairs of legs like oars, causing the water behind those legs to propel it forward as the surface of the valley rebounds like a trampoline.

Although the rowing motion does create tiny waves, "the waves do not play a significant role in the momentum transfer necessary for propulsion," the researchers wrote. "The momentum transfer is primarily in the form of subsurface vortices."

Hu and Chan gathered water striders in nets from Fresh Pond Reservoir in Cambridge and Walden Pond in Concord and brought them back to aquaria in MIT's Applied Mathematics Laboratory. Using particle tracking, dye studies and a high-speed video camera on loan from MIT's Edgerton Educational Center, they photographed the distinctive curlicue patterns made by the striders as they moved.

The striders are hatched under water but live on the surface. If they do happen to end up under water, it takes an enormous amount of force-akin to lifting 100 times their body weight-to climb out. There are hundreds of species of water striders, and as they increase in size, their legs must become proportionally longer for them to be viable water-walkers. The giant Vietnamese water strider, at 20 centimeters long, is the biggest such insect that is still able to walk on water.

The striders, which are found on ponds, rivers and the open ocean, can propel themselves to speeds of 150 cm per second. Their legs are covered with fine hairs that keep them afloat. They have two gaits: a glide that easily transports it one body length (1 cm) at a time, or a leap that propels it into the air and forward.

Chan designed and built a mechanical water strider. Robostrider is made out of a 7-Up can, stainless steel wire legs and an elastic band coupled to a pulley to power its middle legs. Light enough not to break through the water surface, it travels half a body length per stroke. Like its natural counterpart, Robostrider's principal means of transferring momentum is in the form of vortices shed by the rowing action.

Hu's doctoral thesis is on the propulsion mechanism of various surface swimmers, which all rely on manipulating the water surface to generate thrust. He is looking at Microvelia, a beetle that propels itself by ejecting surfactants; Mesovelia, a marsh insect that can climb menisci (bumps in the water surface), and the freshwater pond snail Physidae, which can propel itself on both hard surfaces and inverted beneath air-fluid interfaces.

This work is supported by the National Science Foundation.