Day: 09/18/2014

‘Artificial eye’ to detect particles

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Human eye
The algorithm was inspired by the retina’s efficient ability to recognise patterns
The human eye has inspired physicists to create a processor that can analyse sub-atomic particle collisions 400 times faster than currently possible.

In these collisions, protons – ordinary matter – are smashed together at close to light speeds.

These powerful smash-ups could yield new particles and help scientists understand matter’s mirror, antimatter.

The experimental processor could speed up the analysis of data from the collisions.

Published in the pre-print arXiv server, the algorithm has been proposed for possible use in Large Hadron Collider (LHC) experiments at Cern in 2020. It could also be useful in any field where fast, efficient pattern recognition capabilities are needed.

The processor works in a similar way to the retina’s incredible ability to recognise patterns extremely quickly.

Snapshots in time

That is, individual neurons in our retinas are specialised to respond to particular shapes or orientations, which they do automatically before our brain is even consciously aware of what we are processing.

Image of particle decay
LHC machines produce 40 million collisions per second

Cern physicist Diego Tonelli, one of a team of collaborators of the work, explained that the “artificial retina” detects a snapshot of the trajectory of each collision which is then immediately analysed.

These snapshots are then mapped into an algorithm that can run on a computer, automatically scanning and analysing the charged particle trajectories, or tracks. Exposing the detector to future collisions will then allow teams sift out the interesting events.

Data crunching

Speed is of the essence here. There are roughly 40 million collisions per second and each can result in hundreds of charged particles.

The scientists then have to plough through an incredible amount of data. It’s spotting the deviations from the norm that may give hints of new physics.

LHCb experiment
The LHC will be switched on again in early 2015

An algorithm like this could therefore provide a useful way of crunching through this vast amount of data, in real time.

“It’s 400 times faster than anything existing or foreseen for high energy physics applications. If implemented in a real experiment it will allow us to collect more interesting data more quickly,” Dr Tonelli told the BBC.

Flavour physics

The LHC has been switched off since February 2013 but is due to begin its hunt for new physics in 2015 when the giant machine will once again begin smashing together protons.

As this happens, they break down and free up a huge amounts of energy that forms many neutral and charged particles. It’s the trajectories of the charged ones that can be observed.

Particle collisions
A collision in the Large Hadron Collider creates tracks of charged particles

The new algorithm is not aimed at the type of physics used to find the famous Higgs boson, instead it’s intended to be used for “flavour physics” which deals with the interaction of the basic components of matter, the quarks.

Commenting on the work, Tara Shears a Cern particle physicist from the University of Liverpool, said it could be extremely useful to automatically “give us most information about what we want to study – Higgs, dark matter, antimatter and so on. The artificial retina algorithm looks like it does this brilliantly”.

“When our detectors take these snapshots of the collisions – to us that’s like the picture that your eye sees and when your brain is scanning that picture and making sense of it, well we try and codify those rules into an algorithm that we run on computers that do the job for us automatically,” Prof Shears told the BBC’s Inside Science programme.

“When the LHC continues… we will start to operate with a more intense beam of protons getting a much higher data rate, and then this problem of sifting out what you really want to study becomes really really pressing,” she added.

“This artificial retinal algorithm is one of the latest steps in our mission to [understand the Universe], and it’s really good, it does the job vast banks of computers normally do.”

The algorithm has been developed with the 2020 upgrade of the LHC in mind, which will have even more powerful collisions.

 

LHCb and the search for antimatter

  • The LHC Beauty (LHCb) detector is designed to answer a specific question: where did all the antimatter go?
  • Antimatter is a mirror image of the matter that makes up the world we are familiar with. “Normal” matter consists of particles, while antimatter is made up of antiparticles, identical in mass but with opposite electric charge
  • The theory goes that equal amounts were forged during the intense heat of the Big Bang but today we find no evidence of, for example, antimatter galaxies or stars
  • LHCb investigates the slight differences between matter and antimatter by studying a type of particle called the “beauty (b) quarks”
  • ‘b’ and ‘anti-b’ quarks are unstable and short-lived, they rapidly decay into a range of other particles. Physicists believe that by comparing these decays, they may be able to gain useful clues as to why the Universe is dominated by matter rather than antimatter
  • To do this LHCb produces many different types of quark when the particle beams collide
  • In order to catch the beauty quarks, LHCb has developed sophisticated movable tracking detectors close to the path of the beams circling in the Large Hadron Collider

Just what exactly is Freudian?

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Sigmund Freud

It’s 75 years since the death of Sigmund Freud, and the words and phrases he popularised are deeply ingrained in popular culture and everyday language. How did Freudian jargon become so widespread?

There’s the Freud in textbooks. The bearded Viennese polymath who pioneered psychoanalysis. The Freud that academics never tire of arguing about.

Then there’s the other Freud. The pub Freud. The one you might allude to when you mention dreams, or verbal slips, or someone fancying their mum. His relationship to the first Freud is tangential at best.

Eavesdrop on a conversation and it’s likely that, sooner or later, a concept invented or popularised by the founding father of free association will pop up.

Oedipus complex. Denial. Id, ego and super-ego. Libido. Death wishes. Anal retentiveness. Defence mechanisms. Displacement. Phallic symbols. Projection. Transference. And, of course, Freudian slips.

It’s not just Freud’s terminology that is all over the popular lexicon. He’s an adjective in his own right.

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Some Freudian terms

Freudian terms on banners, in display at Jewish museum in Berlin
  • The unconscious (or subconscious): Freud said that much of what we think is hidden from our waking minds, in our unconscious or subconscious; forbidden wishes and unacceptable thoughts can escape in a distorted way through dreams and “Freudian slips”.
  • Oedipus Complex: Freud’s term for the complex set of emotions which occur between children and their parents – named after the tragic figure of Sophocles’s Greek drama, who – without knowing it – killed his father and married his mother
  • Id, ego and super-ego: A “structural” theory of the mind, which separates it into the id – the realm of uncoordinated and instinctual appetites, the super-ego which plays a critical and moralising role, and the ego, which aims a balance between the two.

 

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“What would Freud think?” and “Ooh, that’s a bit Freudian” are basically “nudge nudge, wink wink” for the sort of person who is very keen to let you know they went to university.

Other 20th Century intellectuals can’t compete. Not Sartre or Chomsky or Einstein. Film reviews in red-top tabloids rarely name-drop Foucault or de Beauvoir.

But everyone knows what you’re on about when you mention Freud. Or at least they think they do. The unconscious. Sexual repression. Dreams. Mummy and daddy issues.

“You don’t have to read Freud to live in a world where Freud is important or to think in a Freudian way,” says Stefan Marianski of the Freud Museum in London. All you need to do is consume mass popular culture produced from the mid-20th Century onwards.

Freud had the advantage of being an extremely good writer, who would illustrate psychoanalysis with reference to the work of great artists such as Shakespeare, Dostoevsky and Leonardo da Vinci.

Detail from poster for Alfred Hitchcock's Spellbound
Alfred Hitchcock’s 1945 film Spellbound centres on psychoanalysis

But, believes psychologist Oliver James, author of Love Bombing, “The reason Freud became such a major cultural force is that he was brought into popular culture first through feature films.” Starting with Alfred Hitchcock’s 1945 psychoanalysis-themed thriller Spellbound, overt references to Freud have abounded in cinema.

Most notably, there’s virtually the entire output of Woody Allen – as he says at the start of Annie Hall: “I never had a latency period”. Then there’s the father-son dynamic of The Empire Strikes Back and, indeed, Back to the Future. “It’s basically the Oedipus complex,” says Marianski. “The logic of Back to the Future is the same as Psycho, really.”

And then you have the stream-of-consciousness novels of Virginia Woolf and James Joyce. Salvador Dali and the Surrealists. The Sopranos and Frasier. The 2011 film A Dangerous Method, starring Viggo Mortensen as Freud. Or indeed anything featuring a repressed memory, a dream sequence or a character with incestuous impulses.

Not that much of this is strictly – in the sense that academic scholars would use the term – Freudian. The gap between the pub Freud and what Freud actually wrote is often quite large.

Although much of his body of thought – not least around “infantile sexuality” – was seen as dangerously radical during his lifetime, the more challenging aspects of his work were rarely dwelt on by the mass media.

Salvador Dali's Lobster TelephoneLobster Telephone by Salvador Dali: Surrealist art was heavilly influenced by Freud’s writings

“I think that most of us have only a vague – perhaps defensively vague – sense of what Freud is really saying, not least because in the field of popular culture his work has often been mediated to us in ways that water it down, make it palatable, reduce its insight, its complexity – and, I suppose, its difficulty – and turn it into a cosy and reassuring fantasy,” says Dr Nicholas Ray, who lectures in Freudian thought at Leeds University.

Typically at the end of the film, the repressed memory is recovered, the heroine is granted self-knowledge and the audience gets a satisfying narrative conclusion.

But even if Freud is widely misunderstood and misrepresented, and the Oedipus complexes portrayed in TV dramas are quite different from the Oedipus complex set out in The Interpretation of Dreams, there is little denying his concepts remain the subject of widespread public fascination.

Stack of books by Sigmund FreudFreud’s work – “mostly read in humanities departments today”

It’s all the more remarkable given that much of what Freud wrote has been superseded by subsequent research, and that in some academic circles his theories have come under fierce attack – not least from feminists, who regard concepts such as penis envy as misogynistic, and accuse him of ignoring evidence that some of his patients had been victims of child abuse.

Freud still has his adherents – not least Oliver James, who says his writings about dreams, the unconscious and the role of early childhood are still valid. But Marianski concedes Freud is “mostly read in humanities departments today” rather than by scientists.

Most of this will have passed the layman by, however. What’s perhaps more significant, Marianski says, is that Freudian language was popularised during a particularly self-obsessed era.

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Sigmund Freud 1856-1939

Viggo Mortensen as Sigmund Freud
Viggo Mortensen as Sigmund Freud in the 2011 film, A Dangerous Method
  • Austrian neurologist and founder of psychoanalysis, regarded as one of most influential – and controversial – minds of the 20th Century
  • Born in Freiberg, Moravia (now Pribor in Czech Republic). Family moved to Leipzig and then settled in Vienna, where Freud studied medicine
  • Developed theory that humans have unconscious in which sexual and aggressive impulses are in perpetual conflict for supremacy with the defences against them
  • His major work The Interpretation of Dreams was published in 1900 in which dreams were explained in terms of unconscious desires and experiences
  • In 1923, he published The Ego and the Id, which suggested a new structural model of the mind, divided into the “id”, the “ego” and the “superego”
  • In 1938, shortly after Nazi annexation of Austria, Freud left Vienna for London, where he died the next year

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“From a historical perspective, he’s part of a general movement where people start to look more into themselves,” says Marianski. “There was a broad cultural shift in our culture – how you conceptualise the self?”

But there is much in Freud’s writing that makes the continued prominence of his terms appear incongruous. In particular, his theories of repression belong very much to a pre-sexual revolution world.

“Now that young people seem to be at liberty to do whatever they want and talk about whatever they want, it’s very interesting that Freud would still be very interesting to them,” says James.

No doubt this won’t stop people from picking and choosing Freudian terms as they see fit in the service of a great 21st Century activity – putting themselves and others on the proverbial couch.

As WH Auden wrote after Freud’s death, “To us he is no more a person / now but a whole climate of opinion”.

It’s more elegant than “pub Freud”.

Ebola ‘threat to world security’

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Health workers in Liberia take a suspected patient into a treatment centre
Health workers have been struggling to contain the outbreak in West Africa – this woman was one suspected case in Liberia

The UN Security Council has declared the outbreak of the Ebola virus in West Africa a “threat to international peace and security”.

The council unanimously adopted a resolution calling on states to provide more resources to combat the outbreak.

UN Secretary General Ban Ki-moon warned an emergency meeting of the council that the number of Ebola infections was doubling every three weeks.

More than 2,600 people have now died in the worst Ebola outbreak on record.

Cases doubling

Mr Ban said the “gravity and scale of the situation now require a level of international action unprecedented for a health emergency”.

A child holds up a poster which details ways to identify the Ebola virus in Freetown, Sierra Leone (18 September 2014)
The UN heard that the international response would need to be 20 times greater than it is now if the outbreak were to be controlled
US Ambassador to the UN Samantha Power at the vote during the Security Council meeting on the Ebola crisis at the UN headquarters in New York (18 September 2014)
Never before has the United Nations Security Council met to confront a public health crisis

He announced the establishment of an “emergency UN mission” working with the World Health Organization (WHO) to combat the crisis, saying he would convene a “high-level meeting” next week.

The council heard that the international response had to be three times bigger than it was now to contain the crisis – the number of cases is doubling every two weeks in west Africa.

The resolution attracted 130 co-sponsors – a UN record – and calls on countries to provide urgent aid, such as medical staff and field hospitals.

The resolution also calls for travel bans imposed by some states to be lifted, saying the countries need to have access to aid instead of being isolated.

Liberian nurses escort a suspected Ebola patient into the John F. Kennedy (JFK) Ebola treatment centre in Monrovia (18 September 2014)The disease is spreading quickly in West Africa, with the number of cases doubling every two weeks
American air force soldiers stand outside a US military aircraft after landing at Roberts International Airport outside Monrovia (19 September 2014)The UN Security Council resolution calls on countries to provide urgent aid, such as medical staff and field hospitals

Council members heard that the international response would need to be 20 times greater than it was now, if the outbreak were to be controlled.

The Security Council has never previously met to confront a public health crisis, reports the BBC’s Nick Bryant from New York.

It is only the second time that a public health issue has been addressed at the council, the first instance being HIV/Aids, our correspondent adds.

A doctor appearing via video link from Liberia warned that if the international community did not step up its response, “we would be wiped out”.

Meanwhile officials in Guinea searching for a team of health workers and journalists who went missing while trying to raise awareness of Ebolahave found several bodies.

A spokesman for Guinea’s government said the bodies included those of three journalists in the team.

They went missing after being attacked on Tuesday in a village near the southern city of Nzerekore.

In Sierra Leone a three-day curfew or lockdown intended to stop the spread of the virus has come into effect.

The aim of the move is to keep people confined to their homes while health workers isolate new cases and prevent Ebola from spreading further.

Critics say the lockdown will destroy trust between doctors and the public.

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The BBC looks at the scale of the challenge the Ebola outbreak presents

Ebola virus disease (EVD)

  • Symptoms include high fever, bleeding and central nervous system damage
  • Spread by body fluids, such as blood and saliva
  • Current outbreak has mortality rate of about 55%
  • Incubation period is two to 21 days
  • There is no proven vaccine or cure

10 Things We Can Learn From the World’s Greatest Surgeon .

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On July 12, 2008, the world lost an incredible talent. A renegade physician, a pioneer, the father of open-heart surgery, and perhaps the best surgeon who ever lived, Dr. Michael DeBakey died of natural causes at 99. Because of his groundbreaking research, cutting-edge medical devices and maverick approach to cardiac surgery, DeBakey literally changed the rules of the game and thousands of lives are saved each day. What can we learn from Michael DeBakey’s life and career? 1. Build your brand. With a career that spanned more than 70 years, DeBakey built a reputation for being indispensable. His patients included everyone from the ordinary person next door and people with no means to a list of Who’s Who among world leaders. Presidents Kennedy, Johnson and Nixon, President Boris Yeltsin, King Hussein of Jordan, the Shah of Iran, Turkish President Turgut Ozal, just to name a few, engaged DeBakey because they knew he was the best. The Journal of the American Medical Association said in 2005, “Many consider Michael E. DeBakey to be the greatest surgeon ever.” Is your personal brand strong enough that if you left your company, colleagues and customers would have a difficult time getting along without you? 2. Be a guru, thought leader, industry expert. Dr. DeBakey published more than 1,000 medical reports, research papers, chapters and books on topics related to cardiovascular medicine. He helped establish the National Library of Medicine, the world’s largest and most prestigious repository of medical archives. DeBakey played a key role in organizing a specialized medical center system to treat soldiers returning from the war. This system is now the Veterans’ Administration Medical Center System. For his numerous contributions Dr. DeBakey was awarded the Presidential Medal of Freedom, the Congressional Gold Medal, Congress’ highest civilian honor, the National Medal of Science, the country’s highest scientific award, and The United Nations Lifetime Achievement Award. Do people see you as a guru in your field? How distinctive is your knowledge base? How well do you garner, contribute and leverage knowledge? 3. Never quit learning. As a child, DeBakey was required to borrow a book from the library each week and read it. He read the entire Encyclopedia Britannica before entering high school. Overseeing cases, consulting with colleagues and mentoring younger surgeons, he made his mark on the world right up to the end. DeBakey performed his last surgery at age 90 and continued to travel the globe giving lectures. Perhaps you’re thinking, “Who would want a 90-year-old surgeon operating on them?” The answer could be, “Someone who’s performed more than 60,000 cardiovascular procedures in his career.” Do you have a reputation for lifelong learning, for continually adding value? When we stop bringing something new to the game, the game is over. 4. Risk more, gain more. DeBakey took risks others weren’t willing to take to advance medicine. Tubing, clamps, pumps, protocols all bear the mark of DeBakey’s passion for innovation. Yet, product and process innovations often pull people out of their comfort zones and some of DeBakey’s early breakthroughs weren’t accepted initially—in fact they were ridiculed. For example, in 1939, when Drs. DeBakey and Alton Ochsner linked cigarette smoking to lung cancer, many in the medical community derided it. Then in 1964, the Surgeon General confirmed their findings and documented the cause and effect. There was also skepticism when DeBakey discovered that he could substitute parts of diseased arteries with synthetic (Dacron) grafts—a procedure that enables surgeons to repair aortic aneurysms in the chest and abdomen. He initially figured out how to stitch synthetic blood vessels on his wife’s sewing machine. Now the procedure is widely used. DeBakey was also the first to perform bypass surgery and the first to perform a successful removal of a blockage of the carotid (main) artery of the neck, a procedure that has become the standard protocol for treating stroke. Those who are unwilling to take risks do not change the world. Is your passion for advancing your field by taking a risk bigger than your fear of rejection or by making a mistake? 5. Refuse to sell out on your dream. DeBakey developed an interest in medicine in his father’s pharmacy where he listened to physicians talk shop. The vision to become a doctor was clear, the question was, “what kind?” In 1932, there simply wasn’t anything you could do for heart disease, if a patient had a heart attack the long-term prognosis wasn’t good. While he was still in school in 1932, DeBakey invented the roller pump—a critical part of the heart-lung machine that takes over the functions of the heart and lungs during open-heart surgery. This not only created the era of open-heart surgery, it cemented DeBakey’s passion to make a mark in the world of cardiovascular medicine. Engagement is about pouring your heart, mind and soul into a dream that causes you to fire on all cylinders. Does your career fulfill your desires? Or, have you sacrificed a dream that could make you come alive for a life of duty and routine that simply “works”? 6. Play to your genius. DeBakey said, “I like my work, very much. I like it so much that I don’t want to do anything else.” Most people who are happy in life spend time doing what they love. This usually makes them extremely good at what they do. Dr. DeBakey exemplified the power of what can happen when our work requires what we are good at and passionate about. Playing to your genius is about using your gifts and talents to pursue a passion that makes a significant contribution to the people and the world you serve. Playing to your genius also promotes autonomy and self-direction, cultivates commitment, stimulates personal growth and makes work fun. Are you engaged in work you’re good at and passionate about—work that makes a contribution and needs to be done? Or are you just biding time? 7. Balance passion with discipline and focus. With regard to his patients, the indefatigable DeBakey had an uncompromising dedication to perfection. He was known as a taskmaster who set very high standards, yet he never demanded more from others than he demanded from himself. Heart surgeons who trained under DeBakey say he was hard to keep up with when making patient rounds. They joked that he was from another world because he could maintain his focus and intensity for hours. In a world of competing priorities and information overload it’s easy to lose focus and get distracted. But, if you are playing to your genius and doing what you love, it’s easier to be disciplined and maintain a maniacal focus. Are you disciplined? Do you have a maniacal focus? Would your customers (internal and external) say you are relentless when it comes to pursuing perfection? 8. Find a void and figure out how to fill it. Michael DeBakey’s innovations are on par with the likes of Thomas Edison, Alexander Graham Bell, Jonas Salk, Henry Ford and Alfred Nobel. During World War II, he helped establish the mobile army surgical hospitals or MASH units. He was a key player in the development of artificial hearts, artificial arteries and bypass pumps that help keep patients alive who are waiting for transplants. He was among the first to recognize the importance of blood banks and transfusions. He also helped create more than 70 surgical instruments that made procedures easier and clinical outcomes more effective. If something couldn’t be done, DeBakey found a way to do it. In 1967, Dr. Christiaan Barnard performed the first human heart transplant in South Africa. Dr. DeBakey was among the first to begin doing the procedure in the United States. The problem was that recipients’ bodies rejected the new organs and death rates were high. In the 1980s cyclosporine, a new anti-rejection drug paved the way for organ transplants. Again, DeBakey was among the first to develop new protocols and advance the field of heart transplants. Where are the gaps in your organization or industry? What would happen if you developed a reputation for filling these voids? 9. Show people that their work matters. Michael DeBakey is known not only for his prolific contributions to the medical field, but also as a symbol of hope and encouragement to his colleagues. Many years ago a colleague of ours shadowed Dr. DeBakey for a day at The Methodist Hospital in Houston, Texas. He was struck by DeBakey’s capacity to affirm each person he saw in the course of the day. In one particular encounter, DeBakey began chatting with an elderly janitor who was sweeping the floor. DeBakey asked the man about his wife and children. He told the older man, obviously not for the first time, that the hospital couldn’t function without the janitor because germs would spread, increasing the chances of infection in the hospital. Later in the day, our colleague tracked down the janitor and asked him, “What exactly do you do? Tell me about your job.” With pride, the janitor replied: “Dr. DeBakey and I? We save lives together.” He’s right. After all, consider what would happen to our healthcare systems if the cleaning crews went on strike. DeBakey understood that showing the janitor exactly how he contributes to a larger, more heroic cause is crucial. This creates a powerful dynamic. Realizing that he is working toward a worthy goal, the janitor’s perceptions about his work changed. It had new meaning and his enthusiasm for the job was rejuvenated. Great leaders make time to help people see how their work is connected to something bigger. For a surgeon like DeBakey, those five or ten minutes each day were costly, unless, of course, you consider the productivity generated by a janitor whose work has been transformed. Right now, how many people in your organization are engaged in work that five years from today no one will give a rip about? Can you make the link between what you do and a noble or heroic cause? Can you make this link for others? 10. Be generative—inspire others to pursue the cause. Generativity is the care and concern for the development of future generations through teaching, mentoring, and other creative contributions. It’s about leaving a positive legacy. All great leaders are generative and Michael DeBakey was no exception. He inspired many medical students to pursue careers in cardiovascular surgery. His reputation brought many people to Baylor College of Medicine and helped transform it into one of the premier medical institutions in the world. DeBakey trained and mentored almost 1,000 surgeons and physicians. In 1976, his students founded the Michael E. DeBakey International Surgical Society. Many of his residents went on to serve as chairpersons and directors of their own successful academic surgical programs in the United States and around the world. Are the people you’ve touched in your career learning, growing and making a difference as a result of your influence? Have they been inspired to build a better world than the world they inherited? Michael DeBakey applied his problem-solving skills to many parts of medicine that have changed our way of life. Timothy Gardner, M.D., president of the American Heart Association said it well, “DeBakey’s legacy will live on in so many ways—through the thousands of patients he treated directly and through his creation of a generation of physician educators, who will carry his legacy far into the future. His advances will continue to be the building blocks for new treatments and surgical procedures for years to come.” Michael DeBakey’s life and legacy proves that one person who chooses to play to their genius can change the world and make it a better place for all. What legacy will you leave behind? ​

Why do chimps kill each other?

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War—what is it good for? “Absolutely nothing” according to the refrain of a 1970 hit song. Many humans would agree with this sentiment. But a major new study of warfare in chimpanzees finds that lethal aggression can be evolutionarily beneficial in that species, rewarding the winners with food, mates, and the opportunity to pass along their genes. The findings run contrary to recent claims that chimps fight only if they are stressed by the impact of nearby human activity—and could help explain the origins of human conflict as well.

Ever since primatologist Jane Goodall’s pioneering work at Gombe Stream National Park in Tanzania in the 1970s, researchers have been aware that male chimps often organize themselves into warring gangs that raid each other’s territory, sometimes leaving mutilated dead bodies on the battlefield. Primatologists have concluded that their territorial battles are evolutionarily adaptive.

But some anthropologists have resisted this interpretation, insisting instead that today’s chimps are aggressive only because they are endangered by human impact on their natural environment. For example, when humans cut down forests for farming or other uses, the loss of habitat forces chimps to live in close proximity to one another and to other groups. Feeding chimps can also increase their population density by causing them to cluster around human camps, thus causing more competition between them.

To test between the two hypotheses, a large team of primatologists led by Michael Wilson of the University of Minnesota, Twin Cities, analyzed data from 18 chimpanzee communities, along with four bonobo communities, from well-studied sites across Africa. The sites included famous chimp and bonobo hangouts such as the Gombe and Mahale national parks in Tanzania, Kibale in Uganda, Fongoli in Senegal, and Lomako in the Democratic Republic of the Congo. The data covered a total of 426 researcher years spent watching chimps and 96 years of bonobo observation. All told, the scientists tallied 152 chimp killings, of which 58 were directly observed, 41 inferred from evidence such as mutilated bodies on the ground, and 53 suspected either because the animals had disappeared or had injuries consistent with fighting.

The researchers created a series of computer models to test whether the observed killings could be better explained by adaptive strategies or human impacts. The models incorporated variables such as whether the animals had been fed by humans, the size of their territory (smaller territories presumably corresponding to greater human encroachment), and other indicators of human disturbance, all of which were assumed to be related to human impacts; and variables such as the geographic location of the animals, the number of adult males, and the population density of the animals, which the team considered more likely to be related to adaptive strategies.

Online today in Nature, the team reports that the models that best explained the data were those that assumed the killings were related to adaptive strategies, which in statistical terms were nearly seven times as strongly supported as models that assumed human impacts were mostly responsible. For example, 63% of the fallen warriors were attacked by animals from outside their own in-group, supporting, the authors say, previous evidence that chimps in particular band together to fight other groups for territory, food, and mates. Moreover, males were responsible for 92% of all attacks, confirming earlier hypotheses that warfare is a way for males to spread their genes. In contrast, the team concludes, none of the factors related to human impacts correlated with the amount of warfare observed.

Pimu, an alpha male chimp at Mahale Mountains National Park in Tanzania, being killed by fellow chimps in 2011.

The study also confirmed earlier evidence that bonobos are, relatively speaking, more peaceful than their chimpanzee cousins. Although fewer bonobo groups were included in the study, the researchers observed only one suspected killing among that species, at Lomako—a site where animals have not been fed by humans and disturbance by human activity has been judged to be low.

“The contrast could not be more stark” between how the two hypotheses fared, says William McGrew, a primatologist at the University of Cambridge in the United Kingdom, who praises the study as a “monumental collaborative effort.” Joan Silk, an anthropologist at Arizona State University, Tempe, agrees. The study “weighs competing hypotheses systematically,” she says. “Advocates of the human impact hypothesis … must challenge [the study’s] empirical findings, or modify their position.”

But leading advocates of the human impacts hypothesis are not giving ground. “I am surprised that [the study] was accepted for publication,” says Robert Sussman, an anthropologist at Washington University in St. Louis, who questions the criteria the team used to distinguish between the two hypotheses. For example, he says, a higher number of males in a group and greater population density—which the researchers used as indicators of adaptive strategies—could equally be the result of human disturbances. Sussman also criticizes the team for mixing observed, inferred, and suspected cases of killings, which he calls “extremely unscientific.”

R. Brian Ferguson, an anthropologist at Rutgers University, Newark, in New Jersey, agrees, adding that other assumptions the team made—such as using larger chimp territories as a proxy for more minimal human disturbances—could be wrong, because “some populations within large protected areas have been heavily impacted.”

As for understanding the roots of human warfare, Wilson says that chimpanzee data alone can’t settle the debate about why we fight: Is it an intrinsic part of our nature or driven more by cultural and political factors? Still, he says, “if chimpanzees kill for adaptive reasons, then perhaps other species do, too, including humans.”

Obesity could bankrupt NHS if left unchecked .

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Chief executive of NHS England warns of catastrophic impact obesity could have on health and rising healthcare costs
Overweight woman

One quarter of the nation’s adults are now obese.

The chief executive of NHS England has warned that obesity will bankrupt the health service unless Britain gets serious about tackling the problem.

“Obesity is the new smoking, and it represents a slow-motion car crash in terms of avoidable illness and rising health care costs,” Simon Stevens told public health officials at a conference in Coventry.

“If as a nation we keep piling on the pounds around the waistline, we’ll be piling on the pounds in terms of future taxes needed just to keep the NHS afloat.”

Stevens, who took up the post this year, said the health of millions of children, the sustainability of the NHS and the economic prosperity of Britain all now depend on a radical upgrade in prevention and public health.

Local authorities have been given responsibility for tackling obesity, as part of their new public health remit. Money for public health has been ringfenced by the government, but individual authorities are free to spend it according to the needs and priorities in their own area. Some experts fear that obesity, which is hard to tackle and needs the involvement of town planners and education departments as well as health, may not get the funding it needs.

Speaking at the annual conference of Public Health England, which is responsible for advising and monitoring the work of the local authorities, Stevens made it clear that obesity could have a catastrophic impact not only on the nation’s health but on the nation’s health service. Nearly one in five secondary school age children and a quarter of adults are obese – up from 15% just twenty years ago, Simons pointed out. If obesity is not checked, there will be a huge rise in avoidable illness and disability. Type 2 diabetes, largely caused by overweight and obesity, already costs the NHS around £9bn, according to Diabetes UK.

Stevens’ proposals for the way forward for the NHS will be published in a report next month. The Five Year Forward View will suggest a number of actions that could make a difference.

• Many of the diseases that shorten lives and put people in hospital are preventable. The report will call for a shift in NHS investment towards targeted and proven prevention programmes. The NHS is now spending more on bariatric (stomach shrinking) surgery for obesity than on the national rollout of the intensive lifestyle intervention programmes that were first shown to cut obesity and prevent diabetes over a decade ago.

• New incentives to ensure the NHS as an employer sets an example. Stevens wants its 1.3 million staff to stay healthy and become health ambassadors in their own communities. Although 75% of NHS Trusts offer their staff help to stop smoking, only a third offer help to keep to a healthy weight. Three-quarters do not provide healthy food for staff working night shifts.

• Financial incentives shoud be offered to employers in England who provide effective workplace health programmes for employees.

• Local councils and mayors should have “devo-max” powers to make decisions over fast food, alcohol, tobacco and other public health matters in their own areas. Stevens cites the public health leadership of Mayor Michael Bloomberg, who banned smoking in public places and has taken tough action against junk food marketing, including his attempt to ban super-size cartons of colas in New York.

Professor Jonathan Valabhji, NHS England’s national clinical director for obesity and diabetes, believes obesity is a significant public health issue.

“We are seeing huge increases in type 2 diabetes because of the rising rates of obesity, and we clearly need a concerted effort on the prevention, early diagnosis and management of diabetes to slow its significant impact not only on individual lives but also on the NHS,” he said.

Artificial Sweeteners May Disrupt Body’s Blood Sugar Controls

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Artificial sweeteners may disrupt the body’s ability to regulate blood sugar, causing metabolic changes that can be a precursor to diabetes, researchers are reporting.

That is “the very same condition that we often aim to prevent” by consuming sweeteners instead of sugar, said Dr. Eran Elinav, an immunologist at the Weizmann Institute of Science in Israel, at a news conference to discuss the findings.

The scientists performed a multitude of experiments, mostly on mice, to back up their assertion that the sweeteners alter the microbiome, the population of bacteria that is in the digestive system.

The different mix of microbes, the researchers contend, changes the metabolism of glucose, causing levels to rise higher after eating and to decline more slowly than they otherwise would.

The findings by Dr. Elinav and his collaborators in Israel, including Eran Segal, a professor of computer science and applied mathematics at Weizmann, are being published Wednesday by the journal Nature.

Cathryn R. Nagler, a professor of pathology at the University of Chicago who was not involved with the research but did write an accompanying commentary in Nature, called the results “very compelling.”

She noted that many conditions, including obesity and diabetes, had been linked to changes in the microbiome. “What the study suggests,” she said, “is we should step back and reassess our extensive use of artificial sweeteners.”

Previous studies on the health effects of artificial sweeteners have come to conflicting and confusing findings. Some found that they were associated with weight loss; others found the exact opposite, that people who drank diet soda actually weighed more.

Some found a correlation between artificial sweeteners and diabetes, but those findings were not entirely convincing: Those who switch to the products may already be overweight and prone to the disease.

While acknowledging that it is too early for broad or definitive conclusions, Dr. Elinav said he had already changed his own behavior.

“I’ve consumed very large amounts of coffee, and extensively used sweeteners, thinking like many other people that they are at least not harmful to me and perhaps even beneficial,” he said. “Given the surprising results that we got in our study, I made a personal preference to stop using them.

“We don’t think the body of evidence that we present in humans is sufficient to change the current recommendations,” he continued. “But I would hope it would provoke a healthy discussion.”

In the initial set of experiments, the scientists added saccharin (the sweetener in the pink packets of Sweet’N Low), sucralose (the yellow packets of Splenda) or aspartame (the blue packets of Equal) to the drinking water of 10-week-old mice. Other mice drank plain water or water supplemented with glucose or with ordinary table sugar. After a week, there was little change in the mice who drank water or sugar water, but the group getting artificial sweeteners developed marked intolerance to glucose.

Glucose intolerance, in which the body is less able to cope with large amounts of sugar, can lead to more serious illnesses like metabolic syndrome and Type 2 diabetes.

When the researchers treated the mice with antibiotics, killing much of the bacteria in the digestive system, the glucose intolerance went away.

At present, the scientists cannot explain how the sweeteners affect the bacteria or why the three different molecules of saccharin, aspartame and sucralose result in similar changes in the glucose metabolism.

To further test their hypothesis that the change in glucose metabolism was caused by a change in bacteria, they performed another series of experiments, this time focusing just on saccharin. They took intestinal bacteria from mice who had drank saccharin-laced water and injected them in mice that had never been exposed any saccharin. Those mice developed the same glucose intolerance. And DNA sequencing showed that saccharin had markedly changed the variety of bacteria in the guts of the mice that consumed it.

Next, the researchers turned to a study they were conducting to track the effects of nutrition and gut bacteria on people’s long-term health. For 381 nondiabetic participants in the study, the researchers found a correlation between the reported use of any kind of artificial sweeteners and signs of glucose intolerance. In addition, the gut bacteria of those who used artificial sweeteners were different from those who did not.

Finally, they recruited seven volunteers who normally did not use artificial sweeteners and over six days gave them the maximum amount of saccharin recommended by the United States Food and Drug Administration. In four of the seven, blood-sugar levels were disrupted in the same way as in mice.

Further, when they injected the human participants’ bacteria into the intestines of mice, the animals again developed glucose intolerance, suggesting that effect was the same in both mice and humans.

“That experiment is compelling to me,” Dr. Nagler said.

Intriguingly — “superstriking and interesting to us,” Dr. Segal said — the intestinal bacteria of the people who did experience effects were different from those who did not. This suggests that any effects of artificial sweeteners are not universal. It also suggests probiotics — medicines consisting of live bacteria — could be used to shift gut bacteria to a population that reversed the glucose intolerance.

Dr. Frank Hu, a professor of nutrition and immunology at the Harvard School of Public Health who did not take part in the study, called it interesting but far from conclusive and added that given the number of participants, “I think the validity of the human study is questionable.”

The researchers said future research would examine aspartame and sucralose in detail as well as other alternative sweeteners like stevia.

Somatomedins and the Kidneys

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AJKD Blog

Insulin-like growth factors (IGF) are a group of peptides that include insulin and relaxins with a common structural feature of three disulfide bonds linking a variable and a domain chain. Indeed, they were named for this reason, having been previously labeled as ‘somatomedins’ based on their purported biological activity as mediators of the growth hormone (GH, Somatotropin). The GH/IGF axis itself includes these two ligands (IGF-1 and IGF-2), two receptors (IGF receptors 1 and 2), and six high-affinity IGF binding proteins (IGFBP-1 through 7, which primarily inhibit IGF actions). Initially, the IGF were thought to be synthesized primarily in the liver, and responsible for normal somatic growth and development. In the last few decades it has been found that, among other organs, mesangial cells and podocytes also produce IGF-1. With that knowledge, it comes as no surprise that IGF have been implicated not only in normal kidney growth and development…

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Can Exercise Help Treat Addiction?

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While some may joke about being “addicted” to various things — chocolate, coffee or selfies, for instance — addiction is no laughing matter when it involves dangerous behaviors and substances. But more and more research is showing that cardiovascular exercise plays a role in addiction treatment and can reduce the inclination to experiment with these substances.

The Brain Chemistry of Exercise vs. Addiction

The idea that exercise promotes longevity and health is not a modern discovery. Both the ancient Greeks and Romans recognized the importance of prescribing exercise for its health benefits. Though the dosage has changed over the years, a 2012 review study in the British Journal of Pharmacology reports that exercise is “one of the most frequently prescribed therapies in both health and disease.” The study concludes that exercise is so beneficial for health that it should be “considered as a drug.”

With regards to the addicted brain, Mark Smith, professor of psychology at Davidson College, says that exercise may serve as alternative non-drug reward activity, trading in an actual high for a “runner’s high.”

“When you look at how exercise affects the brain, you see that it increases dopamine in a reward pathway,” says Wendy Lynch, associate professor of psychiatry and neurobehavioral sciences at the University of Virginia School of Medicine.

Levels of dopamine and other “feel-good” chemicals are elevated by consuming the things we crave but plummet quickly when we stop. Researchers at the National Institute on Drug Abuse say that incorporating exercise into the addiction treatment process — as well as engaging in physical activity prior to exposure — may help in reducing substance abuse.

“The more likely you are to engage in physical activity, the less likely you are to abuse drugs,” Smith says. Smith, who has researched the behavioral effects of opioids and cocaine for the past six years, says there are a few reasons for the inverse relationship of exercise and drug use.

First, substance abuse often causes a decrease in physical activity, he says. “If you know a substance abuser, that’s their full-time job. They don’t have the discretionary time and income to engage in physical activity and exercise.” Preventing drug use might also correlate with nurture. “Maybe you were exposed to a positive role model early in life, and this positive role model encouraged you to live a healthy lifestyle,” Smith says. “Part of that involved engaging in physical activity, but part of that involved abstaining from illicit drugs.”

“Exercise increases self-esteem, self-efficacy and feelings of well-being,” Smith says. “All of these are negatively correlated with substance abuse. And all of these are protective factors against substance abuse.”

Treating the Various Stages of Addiction

Smith’s research has focused on the notion that physical activity causes a decrease in substance abuse, and in numerous studies, he has shown the powerful effects of exercise on different stages of use and relapse. He studied two groups of rats — one sedentary group with normal lab-cage activity and one group with access to a running wheel. The rats could run as much or little as they desired. After six weeks, Smith and fellow researchers trained the rats to intravenously self-administer cocaine or heroin (or a combination of the two), and then measured how much the rats injected.

“Sure enough, the exercise group self-administered much less cocaine than the sedentary control group,” Smith says. “That was the first evidence of this cause-and-effect relationship — that engaging in physical activity leads to a reduction in substance abuse.”

Smith ran follow-up studies that looked at the ability of exercise to reduce self-administration during different transitional stages of drug administration and drug relapse. “There are several important stages — the first is acquisition abuse,” he says. “No one starts out as a drug addict. Some people will experiment, but most of them will not advance beyond the experiment stage.”

The second stage is maintenance, when an individual engages in regular, consistent abuse but not in a problematic manner, Smith says. “This is how many Americans use drugs — one to two glasses of wine every single night. People do this for years and years with no problems.” The third phase is escalation — where some people gradually increase use over time and continue to do so despite negative consequences.

“Binge use/compulsive use is typically what we think about when someone is in the worst stage of addiction,” Smith says of the fourth stage. “During these binges, there is a highly dysregulated pattern abuse, and this is where people get themselves into trouble. This is the stage associated with overdose, criminal activity and visits to the hospital emergency room.” But Smith’s lab-rat studies provide encouraging evidence that physical activity can curb or prevent drug abuse in all of these stages of the addiction process.

Lynch’s studies at the University of Virginia School of Medicine also support this conclusion, especially for the final stage — relapse. She co-authored a study published in the September 2013 issue of Neuroscience & Biobehavioral Reviews, which showed that “physical activity and exercise activate the same reward pathway as drugs of abuse, through increases in dopamine concentrations and dopamine receptor binding.”

Lynch says that for both nicotine and cocaine, administering exercise during abstinence reduces the changes in the brain that lead to relapse, and the earlier you administer the treatment, the better. “Evidence from both human and animal literature is consistent and shows that exercise can effectively decrease the likelihood of starting and levels of abuse under a controlled situation (non-abuse),” she says. “It can prevent or reduce the likelihood of progressing to abuse or dependence, and it can reduce relapse vulnerability.”

Exercise’s Benefits Extend to Smokers Trying to Quit

Research has also shown exercise may help people quit smoking, which is good news for the 18.1 percent (42.1 million) of people 18 years and older who smoke in the United States, as reported by the Centers for Disease Control and Prevention in 2012.

Michael Ussher, a professor of behavioral medicine at St. George’s University of London, says there is “evidence from more than 30 studies that cigarette withdrawal symptoms and cravings are reduced following a single bout of exercise.” Ussher says sessions of exercise lasting five to 30 minutes have been used in these studies and the effect can last up to 30 minutes. “This evidence is the main rationale for why exercise might help smokers quit,” he says.

As for psychological effects, Ussher says smokers tend to have higher rates of depression than non-smokers, so exercise is beneficial for them because it “reduces depression and anxiety and increases self-esteem and positive mood.”

Ussher cited a study from the Center for Behavioral and Preventive Medicine that asked 281 female smokers to attend three sessions of vigorous exercise a week for a 12-week period while they were quitting. The researchers found that the smoking cessation rates were about twice as high in the exercise group compared with a control group enrolled in a wellness program.

Physical Activity for All

You don’t need to be addicted to reap the benefits of exercise, however. Smith says “moderate intensity for moderate time typically makes most people feel good.” The Centers for Disease Control and Prevention and the American Heart Association recommend at least 30 minutes of moderate-intensity aerobic activity at least five days per week or 25 minutes of vigorous aerobic activity at least three days per week. The groups also recommend moderate- to high-intensity muscle-strengthening activity at least twice a week for additional benefits.

This can include power walking, water aerobics, riding a bike on flat land or pushing a lawn mower, according to the CDC. Vigorous activities include jogging, swimming laps, riding a bike quickly or up a hill and playing basketball. Whether it’s running, playing sports or walking around the park, Smith suggests engaging in any activity you enjoy that gets your heart rate up. “That’s the exact same thing your primary care physician would tell you.”

Clonidine Infusions—Do They Have a Role in the PICU?

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The requirement for mechanical ventilation remains one of the primary reasons for ongoing care in the PICU setting. The presence of an endotracheal tube for mechanical ventilation in the pediatric patient mandates the need for ongoing sedation and analgesia. Although the exact suffering endured during mechanical ventilation may be impossible to estimate in preverbal infants and children, the adult literature gives us some insight into such issues. In a follow-up study performed 12 months after discharge from the ICU of 113 adults who survived for more than 1 year, approximately one fourth of the patients who initially would have chosen mechanical ventilation would have refused this therapy if the pain or discomfort would have been any greater.[1] Additional factors other than physical pain may further increase the requirements for sedation and analgesia during mechanical ventilation. These include emotional pain from separation from parents, disruption of the day-night cycle, unfamiliar people, and the incessant noise of machines and monitors. These factors mandate the need for compassionate and humanitarian interventions during ongoing care in the PICU setting. Although nonpharmacologic measures may decrease the impact of these factors, pharmacologic intervention is generally necessary during mechanical ventilation in the PICU patient.

Given these concerns, the potential for complications with inadequate sedation during mechanical ventilation, and scientific data suggesting the deleterious effects of untreated pain, the current trend in most PICUs is to aggressively sedate infants and children during mechanical ventilation. In the majority of PICUs, this is accomplished with a combination of a benzodiazepine (usually midazolam) and an opioid (morphine or fentanyl). Although we have been successful in the goal of achieving effective sedation in the majority of patients, the prolonged use of sedative and analgesic agents may result in adverse effects, including tolerance, physical dependency, and withdrawal if the agents are abruptly discontinued.[2,3] Furthermore, the ongoing use of these agents may cause respiratory depression limiting weaning from mechanical ventilation and decrease gastrointestinal motility preventing enteral feeding. In an effort to decrease or eliminate such problems, attention has turned to the use of adjunctive agents which may decrease the requirements for benzodiazepines and opioids thereby limiting their adverse effect profile.

In this issue of Pediatric Critical Care Medicine, Hunseler et al[4] present the results of a multicenter study evaluating the effects of a clonidine infusion on fentanyl and midazolam requirements during sedation for mechanical ventilation. From the start, Hunseler et al[4] are to be congratulated for undertaking this difficult, labor intensive study which was conducted at several pediatric centers throughout Germany. The study design (prospective, blinded, and randomized) and conduct were exemplary and provide the basis for obtaining valuable information without the inherent deficiencies of less robust trials. From the start, the authors note that their trial is the first prospective, randomized trial in the literature evaluating the effects of the α2-adrenergic agonist, clonidine, in providing sedation during mechanical ventilation. Over a 4- to 5-year period, they were able to enroll a total of 219 patients, ranging in age from 1 day to 2 years. The patients were stratified and the data analyzed in 3 age ranges: 1–28 days, 29–120 days, and 121 days to 2 years. The multicenter trial included 21 university and tertiary care neonatal ICU and PICUs. On day 4 of mechanical ventilation, the patients were randomized to receive a continuous infusion of clonidine (1 μg/kg/hr) or saline placebo. The infusion was continued for 72 hours. Dosages of fentanyl and midazolam were adjusted using the Hartwig sedation scale with a goal score ranging from 9 to 13. The Hartwig scale was chosen given its widespread use in Germany. Following the termination of the infusion, withdrawal was evaluated and graded using the Finnegan score. The primary outcome was the requirements for fentanyl and midazolam.

Unfortunately, only the youngest age group (1–28 d) demonstrated any significant difference with a decrease in both fentanyl and midazolam requirements. Additionally, there was a decrease in the sedation and withdrawal scores in this age group. No differences were noted in the other two age groups; however, a pharmacokinetic analysis demonstrated significantly lower clonidine plasma concentrations in these two groups when compared with the 1- to 28-day-old patients. This left the authors to conclude that their findings were perhaps related to inadequate plasma concentrations of clonidine.

Although not addressed in their article, the primary question relates to the reasons for differences in choice of medications across national and continental lines. In the United States, clonidine is used primarily as an adjunct to regional anesthesia and occasionally administered orally to treat withdrawal following the prolonged administration of various sedative and analgesic agents.[3,5] Clonidine is rarely administered via the IV route.

Like clonidine, dexmedetomidine is a centrally acting, α2-adrenergic agonist and exhibits the same physiologic effects. However, it possesses an affinity eight times that of clonidine for the α2-adrenergic receptor with a differential α1 to α2 agonism of 1:1,600, and a half-life of 2–3 hours, thereby allowing its titration by IV administration. Dexmedetomidine is currently approved by the U.S. Food and Drug Administration for two indications in adults including the short-term (24 hr or less) sedation of adult patients during mechanical ventilation and for monitored anesthesia care. Despite the lack of specific pediatric indications, it continues to be used extensively in PICUs and operating rooms throughout the United States.[6] Its pharmacokinetic properties have been well studied in the pediatric population in various clinical scenarios and in the presence of comorbid conditions including congenital heart disease.[7] Unfortunately, like clonidine, there are few prospective, randomized trials determining its true utility in the neonatal and pediatric population and its lack of formalized approval by regulatory boards limits its use in some centers. The decision to use clonidine may be driven by costs. Although acquisition costs vary, currently at our institution, a vial of clonidine (1,000 μg in 10 mL) costs approximately $13.58. Therefore, the medication cost for an infusion at 1 μg/kg/hr for a 10-kg patient would be $3.26 compared with $46.61 for a dexmedetomidine infusion at 0.5 μg/kg/hr. The latter calculation assumes an acquisition cost of $77.68 for a 2-mL dexmedetomidine vial (100 μg/mL). The cost of dexmedetomidine may decrease slightly as hospitals start using a new diluted version (200 μg/50 mL vial) which costs $64.73 per vial.

Although the primary purpose of the current study was to decrease fentanyl and midazolam requirements and perhaps the prevalence of withdrawal and physical tolerance, the potential benefits may extend far beyond these issues. In the recent years, concern has been expressed regarding the long-term neurocognitive effects of agents that act as agonists at gamma amino butyric acid (GABA) receptors or antagonists at the n-methyl-d-aspartate receptor.[8,9] Animal data have clearly shown that prolonged exposure to these agents during the early vulnerable stages of neuronal development can lead to accelerated apoptosis and potentially long-term neurocognitive effects. To date, the human data are conflicting, and there is no clear evidence on which to base strict clinical guidelines. However, if these concerns are valid, the issues would seem to pertain not only to the operating room but also to the prolonged use of such agents in the ICU setting. The available animal studies suggest that the α2-adrenergic agents do not cause accelerated apoptosis and may be protective, blunting the effect of other agents.[10–12]Furthermore, as this issue has been shown to be a dose-related phenomenon, any intervention which can decrease the use of the potentially implicated agents may be beneficial.

Although the benzodiazepines remain a time-honored agent for sedation in the ICU, additional concerns continue to mount regarding the potential impact that these agents have on long-term consequences of a prolonged ICU stay including delirium. Delirium may occur in up to 80% of critically adults. It may be either a marker for or a direct cause of both short-term and long-term mortality of ICU patients.[13] Although the etiology is multifactorial, the sedation regimen may play a role. The most compelling evidence suggests that medications which act through the GABA system increase the likelihood of delirium. Most notable of the GABA agonists in the role of delirium are the benzodiazepines including both midazolam and lorazepam.[14]Riker et al[15] compared dexmedetomidine (0.2–1.4 μg/kg/hr) with midazolam (0.02–0.1 mg/kg/hr) in 375 medical/surgical adult ICU patients that required sedation for mechanical ventilation. There was no difference in the time spent at the targeted Richmond Agitation Sedation Scale scores; however, there was a decrease in the prevalence of delirium (54% vs 76.6%) and a decrease in the time to tracheal extubation (3.7 d vs 5.6 d) in the patients who received dexmedetomidine. The lack of non-rapid eye movement sleep with the prolonged use of specific sedative agents is one of the physiologic factors that may lead to delirium during prolonged ICU stays. Unlike the benzodiazepines, α2-adrenergic agonists do not disrupt the sleep cycle and may play a role in decreasing the prevalence of delirium. The latest rendition of the sedation guidelines from the American College of Critical Care Medicine in conjunction with the Society of Critical Care Medicine and the American Society of Health-System Pharmacists reflects these new concerns and recent clinical findings. In their summary of the literature regarding sedation of adults in the ICU, they noted that the data provided class +2B evidence suggesting that sedation strategies using nonbenzodiazepine sedatives (either propofol or dexmedetomidine) may be preferred over sedation with benzodiazepines (either midazolam or lorazepam) to improve clinical outcomes in mechanically ventilated adult ICU patients.[16]

The increasing literature and evidence-based medicine in both the adult and pediatric population suggest that sedation regimens incorporating the α2-adrenergic agonists may offer several benefits. The exact benefit may vary from the adult to the pediatric population, and therefore, we are compelled to encourage future studies which more clearly define these benefits in the pediatric-aged patient. To date, there are limited trials comparing these agents to commonly used agents (fentanyl and midazolam) or using them as adjuncts to these agents. There are no data examining optimal dosing regimens for these agents, and as the current study by Hunseler et al[4] demonstrates, we need to further examine the dosing regimens if we want to maximize the benefits of clonidine. Studies are also need to directly compare the two currently available α2-adrenergic agonists, dexmedetomidine and clonidine, to determine if one is superior in regards to its efficacy and its adverse effect profile. Although there are currently cost differences, this may fade as dexmedetomidine enters the generic world.