In science news this week, I was taken by the analogy of how a dinosaur is like a vacuum cleaner. Some of the largest dinosaurs ever to walk the earth, such as the Brachiosarus and the dinosaur-formly-known-as the Brontosaurus (the Apatosaurus) also had the longest necks. Up to nine metres long, it has been assumed that long necks allowed these herbivore dinosaur to reach food high up. However mathematical modelling looking at metabolic rate, blood flow and blood pressure calculated that the dinosaurs would have needed 49% of their total energy requirements to be able circulate their blood up that high. An alternative model is that long necks facilitated a wide radius of low level grazing along the ground – an idea championed by Roger Seymour at the University of Adelaide. From an energy expenditure perspective, dinosaurs with long necks may have looked more like vacuum cleaners, hoovering up all the foliage at ground level.
Dr Melissa told us a fascinating story of a lost experiment, that was left in a cupboard for more than fifty years and the results were published only this month! In the 1950′s Professor Stanley Miller at the University of Chicago ran a series of famous experiments simulating the chemical origins of life on the primordial earth. He mixed various proportions of gases, such as water vapour, methane, hydrogen, and ammonia and fired electric sparks through the mix to simulate lightning strikes. He showed that these reactions produced amino acids, the organic compounds that are the building blocks for proteins, and thus of life itself. After Professor Miller died in 2007, his colleagues were sorting through his lab archives, and found a series of experiments which were run in 1958, and for some reason never analysed. The sealed flasks were set up with a gas mix that had included hydrogen sulfide, and now, using modern analytical techniques, recent analysis shows that two amino acids that contain sulphur, methionine and cysteine, had formed. It just goes to show the benefits of keeping good lab records, and that experiments from the 1950′s can provide insight into the way in which organic molecules may have first formed on the early earth.
Dr Adam reported on the recent publication of a mouse cancer genome project, which uncovered a series of mutations that also cause cancer in humans. Human cancer cells often show a large number of mutations, the majority of which are harmless alterations, acquired over time, as people age. The challenge is to separate out the background mutations from the mutations which are actually causing the cancer. This is where the use of mouse models can be highly informative. The team from Washington University sequenced the genome of tumour cells from mice with a type of cancer of the blood and bone marrow known as acute myeloid leukemia. They found genetic mutations in three genes, each involving a change to a single letter of the DNA sequence, which were identical to genetic changes seen in human patients. This study demonstrates the value of the mouse model for studying human disease, and identifies new targets for cancer drugs.
Dr Shane told us about Australian scientists who analysed altimetry satellite data from 1985-2008 to examine changes in wave heights and wind speeds across the globe. The data show that extreme wind speeds have increased around 10% over the last 20 years and that wave heights are also increasing. Obviously winds and waves are subject to local and seasonal effects, but this study is the first to provide global coverage. The question has been raised as to whether of not changes to winds and waves are linked to changes to the climate. Whilst there is no clear answer at present, altimetry satellite data may provide crucial information on these and other environmental indicators of changes to our oceans.
We were joined in the studio by Shefton Parker and Johannah Shergis from the RMIT School of Health Science who are investigating the ways in which traditional Chinese medicine is being integrated into the health system. Shefton specialises in the use of acupuncture to treat pain relief and nausea. Acupuncture uses sterile stainless steel needles to stimulate “trigger points” in the body and induces an array of physiological responses, including nerve stimulation and hormone release. Shefton is currently involved in a major acupuncture trial for pain relief in patients with acute back pain, migraine and ankle sprain at the Alfred Hospital, Northern Hospital and Epworth Hospital Emergency Departments. These randomised controlled trials are directly comparing acupuncture alone, acupuncture in combination with pharmacotherapy (drugs) and pharmacotherapy alone.
Johannah’s research looks at the use of the traditional chinese herbal medicine ginseng for the treatment of chronic obstructive pulmonary disease (COPD). This condition is an umbrella term for two diseases, chronic bronchitis and emphysema, which involve inflammation and destruction of lung tissue. The use of ginseng as a therapy is based on herbal medicine traditions that are thousands of years old. The current clinical study will examine the therapeutic benefits and safety of a ginseng extract manufactured in tablet form, and assess changes to the quality of life and lung function in COPD patients treated with ginseng. Many current drug treatments, such as the best available drug to treat malaria, are based on traditional chinese medicine, so stay tuned for the results of these exciting studies.
Our next guest was Simon Finlay, the development manager at the Werribee Open Range Zoo to tell us about the new gorilla exhibit. The gorilla breeding program in Melbourne has been very successful over the last few decades and the gorillas are moving from their current home in Parkville to a new gorilla enclosure at Werribee, which will be the largest exhibit of its kind in the Southern Hemisphere (if not the world!). Gorillas are very intelligent animals and the new diverse environment will provide enrichment and stimulus including climbing structures, gorilla-style play equipment and a splash pool. One interesting effect of breeding gorillas at the zoo is that more male babies are born, with a gender ratio of around 70:30 for male to female babies. The new Werribee exhibit will be an important regional breeding facility for groups of male bachelor gorillas, and will provide space for “boys to be boys”. This will mimic social settings that naturally exists in the wild, where young males all hang out as a group, away from the dominant silver back male gorilla. The gorillas will move to their new home at Weribee in June and the grand opening of the new habitat will hopefully be in early July – can’t wait to visit!
Dr Shane gave us a brilliant tutorial in the way altimetry works. Altimetry satellites measure the distance from the air to the surface of the earth and provide a very accurate technique for mapping oceans. The satellites use light, in the form of radar pulses at specific wavelengths, and can also use multiple frequencies. The satellites orbiting the earth will send out a series of pulses, as many as 1700 per second, and measure the round trip time for each pulse. Once you know the time taken, you can calculate the distance travelled, though this relies on having precise knowledge of the satellite location. This powerful technique has a wide range of applications, particularly to studying the ocean, including the wave height and wind speed studies talked about today. Altimetry is also used in studies of the height of the sea surface. This measures effects such as the geoid, which is the height variation due to gravity, an effect which can account for tens of metres of variation in the sea surface. Altimetry also measures ocean circulation, which is linked to the earth’s rotation and also includes measurement of ocean currents and eddies.
This weeks tunes were:
“Mexican Mavis” by Boy and Bear
“Words that maketh murder” by PJ Harvey
“Beautiful Nights” by the Waifs