Latest research from Bristol University

Press release issued: 13 August 2004

re:search is a publication that reviews the latest research from Bristol University, UK. Issue 7 was published on Thursday 12 August 2004.

Review the latest research from Bristol University.

In this issue of re:search:

1 BETTER BEEF AND LAMB
Grass-fed beef and lamb is of superior quality to meat from animals fed on grain-based diets, according to Professor Jeff Wood and colleagues in the School of Clinical Veterinary Science.

They found that grass-fed beef had higher levels of omega-3 fatty acids like those found in fish, when compared with beef fed on grain. Although levels of these fatty acids are lower than in fish, researchers believe their presence could counter the commonly held view that red meat is unhealthy.

Meat from grass-fed cattle also retains its fresh red colour for longer during retail display than grain-fed beef, due to higher levels of the antioxidant vitamin E in the muscle of grazed animals.

2 ADOPTING OLDER CHILDREN
Many families who adopt older children feel abandoned by adoption agencies once the adoption order has been made, according to a new study by Julie Selwyn at the Hadley Centre for Adoption and Foster Care Studies.

The study found that a quarter of all adopters reported being in debt as a consequence of trying to meet the child’s needs and, when they turned to other agencies for help, found these services were “too little, too late”. While a third of adopters reported few problems and a third described family life as a mixture of conflicts and rewards, the remaining third experienced many problems with few or no rewards and escalating behavioural difficulties in the child.

3 IMPACTING ON CLIMATE
Particles of dust, eroded by the wind from bare soils and raised into the atmosphere, can influence regional climates by altering the balance of incoming and outgoing radiation, and affecting chemical processes in the atmosphere. However, the magnitude of this impact on climate is still very uncertain, particularly with regard to whether dust will produce warmer or colder conditions at a regional scale, and how any regional changes might affect the global climate.

Research by Dr Sandy Harrison and colleagues in the School of Geographical Sciences challenges the conventional wisdom that about 50% of the modern dust load is natural and 50% is derived from human activities, primarily agriculture and deforestation.

Their dust-source model found that dust from agricultural and grazing lands contributed less than 10% of the modern dust in the atmosphere, suggesting that the scope for reducing the bad effects of atmospheric dust on urban climates and human health is limited, since most of the dust is natural.

4 BATS SHIFT DOPPLER EFFECT
Bats hunt and navigate at night by emitting a series of ultrasounds that bounce off and return an echo from anything in their path (a process called echolocation). New research by Dr Gareth Jones in the School of Biological Sciences has uncovered just how adept bats are at compensating for the Doppler Effect – those shifts in frequency associated with motion that are familiar to anyone who’s ever heard the change in pitch of an ambulance siren as it passes by.

Dr Jones found that, due to Doppler shifts, flying bats overestimate their distance from their target. However, as a flying bat continues to approach the target between making a call and receiving the echo, the time delay of the echo is shortened and the bat experiences a second error resulting in an underestimate of the target’s distance. By adjusting the frequency, duration and shape of their calls, bats can influence the distance at which these errors are cancelled out, thus ensuring they catch their prey and avoid any obstacles in their way.

5 BRISTOL RISES TO THE CANCER CHALLENGE
Calculations suggest that by the year 2050, cancer incidence rates will have doubled. A number of research teams across the University are currently taking a variety of approaches to tackling this cancer challenge.

These include:

looking at new scanning technology to improve ways of detecting cancer
developing an understanding of how genes control the growth of some common childhood cancers
exploring new forms of cancer ‘prevention’ including better drugs and screening studies
studying the intimate balance between the proteins produced by our bodies that promote cancer growth and other proteins that act to prevent and limit the action of the growth promoter.