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A round-up of the latest science and news from Australasia.

Weekend Treats Undo Healthy Weekdays

Eating well during the week only to binge on junk food over the weekend is likely to be just as bad for your gut health as a consistent diet of junk, according to a study of the gut microbiota of rats.

The human gut consists of up to 100 trillion microbial cells that influence metabolism, nutrition and immune function. Disruption of this microbiota has been linked with gastrointestinal conditions such as inflammatory bowel disease and obesity.

The Paradox of Healthy Obesity

Researchers have defined key characteristics that enable some obese individuals to remain free from type 2 diabetes and other metabolic disorders.

“It has been known for some time that some obese individuals seem to stay metabolically healthy,” said A/Prof Jerry Greenfield of Sydney’s St Vincent’s Hospital and the Garvan Institute of Medical Research. “However, there has been no consensus about how to define ‘metabolically healthy’ obesity – so it has not been easy to understand what underpins these individuals’ apparent protection from disease.”

Breast Cancer Starved by Meat and Dairy Nutrient

The discovery of a significant link between breast cancer and nutrition is leading to a new treatment to “starve” breast cancer cells.

A/Prof Jeff Holst’s team at Sydney’s Centenary Institute stopped breast cancer cells from growing by blocking the proteins that pump key nutrients into the tumour cells. The method has now proven to be effective in preventing the growth of melanoma, prostate cancer and breast cancer cells.

Roaring Cave Reveals How Climate Changed History

Research led by UNSW Australia has produced a 3000-year-long record of climatic variations that may have influenced historical events such as the fall of the Roman Empire and the Viking Age of expansion.

The study of five stalagmites in Roaring Cave in north-west Scotland is the first to use a compilation of cave measurements to track changes in a climate phenomenon called the North Atlantic Oscillation.

Genetic Test Stings Killer Bee Invaders

A new genetic test will enable the importation of honey bees from places where killer bees are present.

Australia needs to import bees that are resistant to the Varroa mite, but are unable to do so due to the risk of introducing the “killer” bee subspecies.

The mite is present in all bee-keeping countries except Australia. It devastates colonies by sucking bees’ blood and spreading blood-borne diseases.

No Australian honeybees have resistance to the mite, so if it managed to evade Australian quarantine measures it could destroy local bee stocks within a couple of years.

Black Holes Behave

Swinburne University researchers have found a formula to predict the masses of black holes in galaxies of various sizes.

While the central black hole in large galaxies is related to the mass of the bulge of stars at the centre of the galaxy, some astronomers have claimed that this is not true for black holes at the centre of galaxies with small bulges.

Immune Phases Influence Depression

Research published in Progress in Neuro-Psychopharmacology & Biological Psychiatry has outlined a new model for clinical depression that takes into account the dynamic role of the immune system. This neuroimmune interaction results in different phases of depression, and has implications for current treatment practices.

An Explosive Way to Fight Bushfires

Explosives have been used to extinguish oil well fires, and now the method is being investigated for bushfires that are out of control. The process is not dissimilar to blowing out a candle: it relies on a blast of air to knock a flame off its fuel source.

Dr Graham Doig of the University of NSW travelled to a high-explosives and bomb test site in a remote part of New Mexico to scale up tests he originally conducted at the University’s heat transfer and aerodynamics laboratory.

A Dinosaur with a Cock’s Comb

By Stephen Luntz

The first evidence of a fleshy crest on a dinosaur has been compared to the comb on modern birds such as roosters.

“It’s very rare for skin to fossilise,” says Dr Phil Bell of the University of New England’s School of Earth Sciences. “You need very unusual conditions. An animal must have been buried rapidly after it died, within 1–2 days, and the chemical conditions need to be just right. Even when this happens, skin is often overlooked in the field because it is so un­expected and delicate and thin.”