Cassini makes another Enceladus flyby

PASADENA, Calif., Nov. 4 (UPI) -- NASA says its Cassini spacecraft has successfully completed another flyby of Saturn's moon Enceladus and is sending data from the event back to Earth.

Astronomers said Cassini has approached Enceladus more closely, but Monday's passage took the spacecraft on its deepest plunge yet through the heart of the plume being emitted from the moon's south polar region.

At its closest point Monday, Cassini flew about 60 miles above the surface of Enceladus, officials said.

"Since the discovery of the plume in 2005, scientists have been captivated by the enigmatic jets," NASA said in a statement. "Previous flybys detected water vapor, sodium and organic molecules, but scientists need to know more about the plume's composition and density to characterize the source, possibly a liquid ocean under the moon's icy surface. It would also help them determine whether Enceladus has the conditions necessary for life."

Space agency mission managers said they conducted extensive research before the flyby to make sure the spacecraft could fly safely through the plume and not use an excessive amount of propellant.

Cassini was launched Oct. 15, 1997, and entered into orbit around Saturn July 1, 2004.

Stairs boost fitness, balance, strength

SCHILLER PARK, Ill., Nov. 4 (UPI) -- U.S. fitness experts say climbing up stairs -- and going down them too -- have multiple health benefits such as improved balance and strength.

Representatives at Life Fitness -- a company in Schiller Park, Ill., that manufacturers exercise equipment such as treadmills say incorporating stairs in a fitness regime will use muscles standard floor exercises don't. Studies, they say, show not only improved balance and strength and improved cholesterol levels in the blood, but longer life. People who climb more than 55 flights of stairs every week live longer, they say.

Among their recommendations for those contemplating adding stair-climbing to their fitness regime, Life Fitness experts suggest:

-- Taking the stairs two at a time, focusing on pushing up with the back of the legs to work the hamstrings rather than pulling with the legs while climbing.

-- Walking down stairs or even downhill has been proven to improve blood sugar and cholesterol levels. However, remember to be careful because it's easier to trip on the way down.

-- Stair climbing workouts do add extra pressure to the knees and joints so pay attention to any hip, knee or ankle pain. Be sure to use the handrails for extra balance.

Early universe supports dark matter theory

STANFORD, Calif., Nov. 4 (UPI) -- U.S. and Welsh researchers say they've obtained a detailed picture of the early universe using a telescope in the Antarctic.

The researchers led by Professors Walter Gear of Cardiff University and Sarah Church of Stanford University said their measurements of the cosmic microwave background provide further support for the standard cosmological model of the universe.

They said their findings confirm the model's prediction that dark matter and dark energy make up 95 percent of everything in existence, while ordinary matter makes up just 5 percent.

"When I first started in this field, some people were adamant that they understood the contents of the universe quite well. But that understanding was shattered when evidence for dark energy was discovered," Church said. "Now that we again feel we have a very good understanding of what makes up the universe, it's extremely important for us to amass strong evidence using many different measurement techniques that this model is correct, so that this doesn't happen again."

The study is reported in The Astrophysical Journal.

Potential leishmaniasis treatments studied

PITTSBURGH, Nov. 4 (UPI) -- U.S. scientists say they've created a new approach that has identified compounds with a potential for treating leishmaniasis -- a parasitic infection.

Medical scientists at the University of Pittsburgh and the Walter Reed Army Institute of Research screened nearly 200,000 chemical compounds and then regrouped them into chemotypes or chemical classes, both new and known, said senior investigator Professor John Lazo, director of the university's Drug Discovery Institute.

"We are making real progress in our effort to find new drugs to treat what I'd call the most neglected of the neglected diseases," Lazo said. "And the method we've developed could be applied to find treatments for other parasitic infections, which are an enormous global health burden."

Assistant Professor Elizabeth Sharlow, who led the research, said investigators used unconventional approaches to find drug candidates. First, they developed an assay based on the promastigote, the Leishmania life cycle stage that infects the sandfly, to measure the candidate's ability to inhibit the parasite's growth.

"Another unusual step we took was to screen compounds at relatively high concentration, which would make them more likely to affect promastigote growth," Sharlow said. "The aim was to maximize the diversity of the active compounds, which we then clustered into similar chemotypes with powerful computational methods to make further testing more manageable."

The study appears in the early online edition of PLoS Neglected Tropical Diseases.

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