A diet of milk could bring twins

Eating milk and other dairy products could increase a woman's chance of having twins, a US doctor is proposing, based on a study of vegan women.

The rate of twin births in the United States rose by more than 75% between 1980 and 2003. Some of this can be explained by the use of fertility treatments, which ups the risk of multiple births. But that can't explain all of the jump, researchers say. Bearing twins is more risky for both mother and child than having a single baby, so scientists want to know what's causing the rise.

Gary Steinman of the Long Island Jewish Medical Center in New Hyde Park, New York, carried out a simple comparison: he gathered together childbearing records for more than 1,000 vegan women who do not eat any animal products. He calculated that vegans were around five times less likely to bear twins than omnivorous women or vegetarians who eat dairy food. His study is published in the Journal of Reproductive Medicine¹.

Eating dairy seems to up the chance of having multiple births.

'Hobbit' stirs scientific clash

A US-British team of scientists has challenged the idea that the tiny skeleton from Indonesia dubbed the "Hobbit" is a new human species.

Writing in Science magazine, the team presents an alternative theory that the remains could be those of a modern human with a brain disorder.

Their arguments appear in a technical critique of previous research into the Hobbit brain also published in Science.

But the authors of that earlier paper have vigorously defended their work.

The skeletal remains were discovered by an Australian-Indonesian research team in the cave of Liang Bua on the island of Flores in 2003.

After carefully analysing the bones, the group declared them to be those of a human species previously unknown to science, and to which they gave the classification Homo floresiensis. (The specimen is also sometimes referred to as LB1 after the cave in which it was found).

'Hobbit' stirs scientific clash

Let's talk about death

Death is a vast mystery, but there are two things we can definitely say about it. It's inevitable and its timing is unknown. Unfortunately we seize on the latter as an excuse to put off facing death directly. Yet the longer we postpone facing death, the more we fear it.

According to mystics and sages from all the great wisdom traditions, denial of death deprives our life of true meaning. Far better to make friends with dying by reflecting on what death might actually feel like and what happens to the mind and body after you die.

Dr Katherine Clark is a staff specialist in palliative care at Royal Prince Alfred Hospital, Sydney. She knows all about the common symptoms experienced by people on their deathbed. "Of course, each person's death is unique," she says. "So you might see only some of these symptoms or none of them."

According to Clark, a person in the last stages of life will typically sleep more. Even so, loved ones are encouraged to keep talking to them. "There's research based on electroencephalograms (EEGs) of people's brain waves that indicates hearing is the last sense to go."

Breathing patterns change too. A dying person may take shallow and quick breaths or slow and laboured ones. They may also make gurgling noises, sometimes referred to as the "death rattle". In fact the sound is caused by air passing through mucus pooled in the person's pharynx, which they're unable to shift through coughing.

Equally distressing to onlookers is Cheyne-Stokes breathing. This is characterised by periods of up to 45 seconds of no breathing at all, followed by deeper and more frequent respirations. It occurs as vital organs are deprived of oxygen and waste products build up.

Hallucinations, agitation, loss of appetite, changes in bowel and bladder function as well as in skin temperature and colour are experienced as oxygen flow to the brain decreases, vital organs shut down, muscles relax and blood moves away from the extremities.

Finally there's the moment of death itself, when the heart stops beating and breathing ceases. Death was once defined as meeting these criteria, but the development of cardiopulmonary resuscitation (CPR) and prompt defibrillation forced a rethink. Doctors now turn to 'brain death' where a definition of death is required.

Let's talk about death

Human, Chimp Ancestors May Have Mated, DNA Suggests

Early human ancestors and chimpanzee ancestors may have mated and produced offspring, according to a new DNA study. The study suggests that the human and chimp lineages initially split off from a single ape species about ten million years ago. Later, early chimps and early human ancestors may have begun interbreeding, creating hybrids—and complicating and prolonging the evolutionary separation of the two lineages.

The second and final split occurred some four million years after the first one, the report proposes.

"One thing that emerges [from the data] is a reestimate of the date when humans and chimps last exchanged genes," said David Reich, a professor at Harvard Medical School's Department of Genetics in Boston.

"Our data strongly suggest that [the last gene exchange] occurred more recently than 6.3 million years ago and probably more recently than 5.4 million years ago," said Reich, senior author of the study, to be published tomorrow in the journal Nature.

"This paper is very interesting, because it provides a hypothesis that is outside of the currently accepted dogma," said Kateryna Makova, a professor at Pennsylvania State University's Center for Comparative Genomics and Bioinformatics who is unaffiliated with the study.

Human, Chimp Ancestors May Have Mated, DNA Suggests

A new twist on the ol' flying car - May 17, 2006

Carl Dietrich, the MIT aeronautical-engineering graduate student who is designing the vehicle, prefers the term "roadable aircraft" -- meaning a plane that drives, not a car that flies.

"We try to steer away from The Jetsons," Dietrich says. "It's a step in that direction, but a baby step."

Still, in an age of hub-centric commercial flights, Dietrich thinks the ability to cruise between two of the 4,800 small airports nationwide and then drive to a final destination, whether your office or vacation home, will be irresistible to amateur pilots.

He and his team are finishing a one-fifth-scale model for wind-tunnel tests. They hope to build a prototype within two years and to have the first Transitions rolling down runways by 2010.

The projected price tag? About $150,000, roughly the price of a fully loaded Ford GT sports car.

A new twist on the ol' flying car - May 17, 2006