Two University of Adelaide health researchers have been appointed Officers of the Order of Australia  in the Australia Day Honours List.
Cerebral palsy researcher Professor Alastair MacLennan AO and mental health expert Professor Alexander McFarlane AO have been honoured for their outstanding service to medical research, in the respective fields of cerebral palsy and women's and children's health, and psychiatry.
Professor Alastair MacLennan  has an international reputation for leading the world's largest research group into the causes of cerebral palsy, which affects more than 30,000 people in Australia.
Named 2009 South Australian Scientist of the Year for Public Good, Professor MacLennan is Head of the Discipline of Obstetrics and Gynaecology  at the Robinson Institute , the University of Adelaide's research arm for reproductive health and early origins of health and disease. He is also a senior visiting specialist at the Queen Victoria Hospital  and Women's and Children's Hospital .
Professor MacLennan and his team of researchers have recruited thousands of Australian families to provide cheek swabs and blood samples to help unravel the mystery of how genetic mutations are linked to cerebral palsy.
The study is the largest of its kind in the world and seeks to find genetic answers to a disability which affects the neuro-motor region of the brain at birth, resulting in poor muscle co-ordination and even quadriplegia.
Professor MacLennan has conducted feto-maternal research since 1970, is the author of more than 340 publications, books and scientific chapters and has also presented at hundreds of international conferences throughout his career.
Apart from his reputation as one of the world's foremost cerebral palsy researchers, Professor MacLennan is also an international expert on menopause and women's health.
He has received millions of dollars in Federal Government health funding for his research into both cerebral palsy and the role of hormone replacement therapy in treating menopausal symptoms.
Professor MacLennan heads the South Australian Cerebral Palsy Research Group , a multidisciplinary group headquartered at the University of Adelaide, which collaborates with national and international researchers.
Professor McFarlane , a qualified psychiatrist and Head of the Centre of Military and Veterans Health  at the University of Adelaide, is an international expert in the field of post traumatic stress disorder and the impact of disasters.
His expertise spans both civilian and military disasters, including the impact of war, natural disasters, motor vehicle accidents and childhood abuse, and he is one of the world's most cited experts in the field of traumatic stress.
Professor McFarlane is currently the Senior Adviser in Psychiatry to the Australian Defence Force .
He is also a past President of both the International and Australasian Societies for Traumatic Stress Studies and a recipient of the prestigious Robert Laufer Award for outstanding scientific achievement in the study of post traumatic stress.
He has acted as an adviser to many international groups in post disaster situations, including the Kuwait Government and the United Nations, as well as run workshops in Europe, the US, Asia and South Africa and trained health professionals in the wake of the Asian tsunami in 2004.
In Australia Professor McFarlane has played a major role in assisting victims of some of the nation's biggest natural disasters, including the recent Queensland floods, the 2009 Black Saturday bushfires in Victoria and the Ash Wednesday bushfires in 1983.
Professor McFarlane has published over 200 articles, 47 chapters in various refereed journals and has co-edited three books.
The Acting Vice-Chancellor and President of the University of Adelaide, Professor Mike Brooks , says the Australia Day honour conferred on both men was "highly deserved recognition for a lifetime body of work".
"Professor MacLennan has spent more than 40 years improving the standards of obstetrics and gynaecology around the world. In that time he has made significant breakthroughs in helping to pinpoint the causes of cerebral palsy, as well as making an outstanding contribution to women's health.
"Professor McFarlane is renowned around the world for his expertise in post traumatic stress and its long term impacts. He has made a huge contribution towards helping to broaden our knowledge and understanding of the psychological effect of war and natural disasters," Professor Brooks said.