Long menopause allows killer whales to care for adult sons

Scientists have found the answer to why female killer whales have the longest menopause of any non-human species - to care for their adult sons. Led by the Universities of Exeter and York and published in the journal Science (14 September 2012) the research shows that, for a male over 30, the death of his mother means an almost 14-fold-increase in the likelihood of his death within the following year.

The reason for the menopause remains one of nature's great mysteries and very few species have a prolonged period of their lifespan when they no longer reproduce, as in humans. However, female killer whales stop reproducing in their 30s-40s, but can survive into their 90s. While different theories have been put forward for the evolution of menopause in humans, including the well-established 'grandmother' hypothesis, there has been no definitive answer to why females of a small number of other species, including killer whales, also stop reproducing part-way through their lives.

The research team, from the Universities of Exeter and York (UK), the Center for Whale Research (USA) and Pacific Biological Station (Canada) analysed records spanning 36 years, of the members of two populations of killer whales (Orcinus orca) in the North Pacific ocean, off the coast of the USA and Canada.

They found that the presence of a female who was no longer reproducing significantly increased her older offspring's survival. In the case of males over the age of 30, a mother's death meant a 14-fold increase in the likelihood of their death within a year. Females also stay within their mother's group but for daughters of the same age, the difference is just under three-fold. For females under the age of 30, the death of their mothers had no effect on their survival rates.

Killer whales live in unusual social groups, with sons and daughters staying with their mothers in a single group throughout their lives. With this close association, older mothers have the opportunity to increase the transmission of their genes by helping their adult offspring survive and reproduce. When sons mate, their offspring are cared for by females in another group, whereas when daughters reproduce the offspring stay in the group, which increases local competition for resources within the group.


Theory predicts that in order to have the best chance of spreading their genes, without carrying an additional burden, mothers should focus their efforts on their sons. This research backs up this theory and demonstrates the extent to which older sons are dependent on their mothers for survival.

Lead author on the paper University of Exeter PhD student Emma Foster said: "Killer whales are extraordinary animals and their social groups are really unusual in that mothers and their sons are lifelong companions. Our research suggests that they have developed the longest menopause of any non-human species so that they can offer this level of commitment to their older offspring."

Dr Dan Franks, from the Department of Biology at the University of York, said: "Our analysis shows that male killer whales are pretty much mommy's boys and struggle to survive without their mother's help. The need for mothers to care for their sons into adulthood explains why killer whales have evolved the longest post-reproductive lifespan of any non-human animal."

Dr Darren Croft of the University of Exeter added: "Both humans and killer whales are unusual in having a long menopause. Although they share this trait, the way older females benefit from ceasing reproduction differs, reflecting the different structure of human and killer whale societies. While it is believed that the menopause evolved in humans partly to allow women to focus on providing support for their grandchildren, it seems that female killer whales act as lifelong carers for their own offspring, particularly their adult sons. It is just incredible that these sons stick by their mothers' sides their entire lives."




Contact: Sarah Hoyle
s.hoyle@exeter.ac.uk
44-013-927-22062
University of Exeter 

New test to crack down on sporting drugs-cheat test

Scientists from three UK universities have developed a new test to catch drugs-cheats in sport.

Over the last 10 years, the GH-2004 team, which is based the University of Southampton, has been developing a test for Growth Hormone misuse in sport with funding from the World Anti-Doping Agency (WADA) and US Anti-Doping Agency and with support from UK Anti-Doping.

The test, developed by scientists at the University of Southampton, King's College London and University of Kent at Canterbury, is based on the measurement of two proteins in the blood, insulin-like growth factor-I and the amino terminal pro-peptide of type III collagen. Both of these proteins, which act as markers of growth hormone use, increase in response to growth hormone.

The test was used for the first time by King's College London analysts at the anti-doping laboratory for the London 2012 Olympic and Paralympic Games.

On 8 September 2012, the International Paralympic Committee announced that two powerlifters had received two year suspensions for Anti-Doping Rule Violations involving Growth Hormone following an adverse laboratory finding using the new markers test.

The case was a world first as some of the latest testing methods were used which were only introduced prior to London 2012. The new method is able to detect misuse of human growth hormone over a number of weeks, compared to previous methods used which only detected use over a shorter time period.

Richard Holt, Professor in Diabetes and Endocrinology at the University of Southampton and also a consultant in Diabetes at Southampton General Hospital, said, "We are pleased to have another effective and reliable means to catch cheats and help deter harmful drug misuse. There has been a tremendous amount of team work to develop this test and I am delighted that this dedication has finally succeeded. I would like to thank the World Anti-Doping Agency, US Anti-Doping and UK Anti-Doping for their support and trust in our work."

Professor David Cowan, Head of the Drug Control Centre at King's College London and Director of the anti-doping laboratory for the Games, said: "These findings prove that the years of research have been worthwhile. In partnership with the University of Southampton and Kent University, this has been one of the most complex scientific projects the Drug Control Centre at King's has been involved in. To be able to carry out this test at this year's Games is a huge achievement. It represents a big step forward in staying at the forefront of anti-doping science, to help deter drug misuse in sport."

Andy Parkinson, UK Anti-Doping Chief Executive, adds: "Continual improvement in testing science is fundamental to the global anti-doping movement, ensuring that sophisticated dopers are caught and those at a tipping point are deterred. I am delighted that this UK developed test, which my team has been closely involved with, was used at the 2012 Paralympic Games to such good effect."

WADA President John Fahey praised the test by saying: "The new test – which has been approved by WADA – was first introduced prior to the London 2012 Olympic Games, and we are confident that it will prove a significant tool in the fight against doping in sport.

"It will complement the test that has been in use since the 2004 Athens Olympic Games, the major difference being that the anti-doping community now has a much longer detection window to work with."

Contact: Becky Attwood
r.attwood@soton.ac.uk
44-023-805-95457
University of Southampton 

Simple tool may help evaluate risk for violence among patients with mental illness

Mental health professionals, who often are tasked with evaluating and managing the risk of violence by their patients, may benefit from a simple tool to more accurately make a risk assessment, according to a recent study conducted at the University of California, San Francisco.

The research, led by psychiatrist Alan Teo, MD, when he was a UCSF medical resident, examined how accurate psychiatrists were at evaluating risk of violence by acutely ill patients admitted to psychiatric units.

The first part of the study showed that inexperienced psychiatric residents performed no better than they would have by chance, whereas veteran psychiatrists were moderately successful in evaluating their patients' risk of violence.

However, the second part of the study showed that when researchers applied the information from the "Historical, Clinical, Risk Management󈞀–Clinical" (HRC-20-C) scale – a brief, structured risk assessment tool – to the patients evaluated by residents, accuracy in identifying their potential for violence increased to a level nearly as high as the faculty psychiatrists', who had an average of 15 years more experience.

"Similar to a checklist a pilot might use before takeoff, the HRC-20-C has just five items that any trained mental health professional can use to assess their patients," Teo said. "To improve the safety for staff and patients in high-risk settings, it is critical to teach budding psychiatrists and other mental health professionals how to use a practical tool such as this one."

The study was published Aug. 31 in the journal Psychiatric Services.

The HCR-20-C was developed several years ago by researchers in Canada, where it is used in a number of settings such as prisons and hospitals. However, in the United States, structured tools such as the HCR-20-C are only beginning to be used in hospitals.

"This is the first study to compare the accuracy of risk assessments by senior psychiatrists to those completed by psychiatric residents," said senior author Dale McNiel, PhD, UCSF professor of clinical psychology. "It shows that clinicians with limited training and experience tend to be inaccurate in their risk assessments, and that structured methods such as HCR-20-C hold promise for improving training in risk assessment for violence."

"The UCSF study was unusual," Teo added, "in applying a shorter version of the tool that could be more easily incorporated into clinical practice."

Teo and his team assessed the doctors' accuracy by comparing the risk assessments that they made at the time patients were admitted to the hospital, to whether or not patients later became physically aggressive toward hospital staff members, such as by hitting, kicking or biting. The study included 151 patients who became violent and 150 patients who did not become violent.

The patients in the study had severe mental illnesses, often schizophrenia, and had been involuntarily admitted to the hospital.

Contact: Abigail Mortimore
abigail.mortimore@ucsf.edu
415-502-6397
University of California - San Francisco