Blog-bin

Astronauts who spend months in space tend to lose bone strength, making them increasingly vulnerable to fractures in later life.

Universities of California (UC) Irvine and San Francisco evaluated 13 astronauts who spent four to six months on the International Space Station and found that, on an average, their hipbone strength decreased 14%.

Three astronauts experienced losses of 20% to 30%, rates comparable to those seen in older women with osteoporosis.

These results alarmed researchers because they revealed a greater rate of bone deterioration than previously measured using less powerful technologies.

Orthopaedic researchers looking into the effects of long-duration spaceflight usually study the hipbone or spine. The hip experiences the greatest rate of bone loss in space, and a hip fracture almost always requires hospitalisation and major surgery.

It can impair a person’s ability to walk unassisted and may cause prolonged or permanent disability or even death. Fractures of the vertebra also have serious consequences, including loss of height, severe back pain and deformity.

“If preventive measures are not taken, some of our astronauts may be at increased risk for age-related fractures decades after their missions,” said Joyce Keyak of UC Irvine, biomedical engineering professor, who led the study.

For as long as there have been astronauts, researchers have studied why the environment of space makes bones more fragile. While previous studies looked at bone mineral density, this study is the first to specifically evaluate bone strength.

Keyak and her colleagues used a novel computer programme she developed over the past 20 years to identify hipbone fracture risk in people with osteoporosis. The study team used this programme to analyse structurally the hipbone CT scans of one female and 12 male International Space Centre crewmembers, said an UCI release.

health, science & technology health, science & technology

An international team of scientists reported on Wednesday it had laid bare the DNA code of sorghum, a hardy tropical cereal whose genes could one day be spliced to produce crops that resist global warming.

Sorghum (Latin name Sorghum bicolor) is related to sugar cane and corn and is grown in arid regions of northeast Africa, India and the southern United States for food, fibre, fuel and animal feed.

Sequencing of the sorghum genome adds to that in 2005 of the rice plant, the world’s most important food plant. Draft sequences of corn, also called maize, and soyabean were unveiled in 2008. Work is underway to sequence wheat, barley, as well as the tomato and potato.

The goal behind genomic sequencing is to find genes that can boost yields to help feed the world’s burgeoning population, or to enable the plant to survive harsh conditions inflicted by climate change.

These genes can then be introduced into other plants, using either traditional breeding techniques or genetic engineering, it is hoped.

The sorghum project, led by Andrew Paterson of the University of Georgia, is reported in this week’s issue of Nature, the British-based science journal.

science & technology science & technology

Rigorous workouts lasting as little as three minutes may help prevent diabetes by helping control blood sugar, British researchers said on Wednesday.

The findings published in the journal BioMed Central Endocrine Disorders suggest that people unable to meet government guidelines calling for moderate to vigorous exercise several hours per week can still benefit from exercise. “This is such a brief amount of exercise you can do it without breaking a sweat,” said James Timmons, an exercise biologist at Heriot-Watt University in Edinburgh, who led the study.

“You can make just as big as an effect doing this as you can by doing hours and hours of endurance training each week.”

Timmons and his team showed that just seven minutes of exercise each week helped a group of 16 men in their twenties control their insulin. The volunteers, who were relatively out of shape but otherwise healthy, rode an exercise bike four times daily in 30 second spurts two days a week.

After two weeks, the men had a 23% improvement in how effectively their body used insulin to clear glucose from the blood stream, Timmons said. The effect appears to last up to 10 days after the last round of exercise, he added.

“The simple idea is if you are doing tense muscle contractions during sprints or exercise on a bike you really enhance insulin’s ability to clear glucose out of the bloodstream,” he said.

health, science & technology health, science & technology