Day: 12/26/2013

Man flu is no myth say scientists, with ‘manly’ men more susceptible

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Men with high levels of testosterone have a secret flaw – less effective immune systems, researchers have discovered

Man flu may not be a myth after all, as scientist have found that men with high levels of testosterone have a hidden flaw – weak immune systems.

The discovery could explain why men are more susceptible than women to a whole range of bacterial, viral, fungal and parasitic infections, researchers said.

It may also be the reason why men’s immune systems respond less strongly to vaccinations against influenza, yellow fever, measles and hepatitis, along with many other infectious diseases.

Those who take testosterone supplements in the quest to gain muscle meanwhile, could be making themselves more susceptible to illness.

“This is the first study to show an explicit correlation between testosterone levels, gene expression and immune responsiveness in humans,” said US lead scientist Professor Mark Davis, from Stanford University.

“It could be food for thought to all the testosterone-supplement takers out there.”

The researchers studied how the immune systems of 34 men and 53 women were stimulated by the flu vaccine.

The jab generated a bigger boost in protective antibodies in women, with further analysis revealing activity that, in high testosterone men, was associated with a weakened antibody response. Men with low testosterone were not affected the same way.

Testosterone’s anti-inflammatory properties may explain why it can weaken the immune system, said scientists writing in the journal Proceedings of the National Academy of Sciences.

Prof Davies said the reason why testosterone weakens the immune system yet boosts muscle power and aggression, may be linked to the man’s evolutionary role.

Men are more likely than women to suffer injuries from competitive encounters, as well as their traditional roles of hunting, defence and potentially dangerous physical work, Prof Davies said. The dampening down the immune system makes male less susceptible to a potentially fatal over-reaction to infections, especially those from wounds.

“Ask yourself which sex is more likely to clash violently with, and do grievous bodily harm to, others of their own sex,” Prof Davis added.

Google robot wins Pentagon contest.

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Schaft won this round of Darpa’s competition by a wide margin

A robot developed by a Japanese start-up recently acquired by Google is the winner of a two-day competition hosted by the Pentagon’s research unit Darpa.

Team Schaft’s machine carried out all eight rescue-themed tasks to outscore its rivals by a wide margin.

Three of the other 15 teams that took part failed to secure any points at the event near Miami, Florida.

Schaft and seven of the other top-scorers can now apply for more Darpa funds to compete in 2014’s finals.

Darpa Robotics Challenge Scoreboard

1. Schaft (27 points)

2. IHMC Robotics (20 points)

3. Tartan Rescue (18 points)

4. MIT (16 points)

5. Robosimian (14 points)

6. Traclabs / Wrecs (11 points)

8. Trooper (9 points)

9. Thor / Vigir / Kaist (8 points).

12. HKU / DRC-Hubo (3 points)

14. Chiron / Nasa-JSC / Mojavaton (0 points)

Darpa said it had been inspired to organise the challenge after it became clear robots were only capable of playing a very limited role in efforts to contain 2011’s Fukushima nuclear reactor meltdown in Japan.

“What we realised was … these robots couldn’t do anything other than observe,” said Gill Pratt, programme manager for the Darpa Robotics Challenge.

“What they needed was a robot to go into that reactor building and shut off the valves.”

In order to spur on development of more adept robots the agency challenged contestants to complete a series of tasks, with a time-limit of 30 minutes for each:

Darpa robotics challenge
The robots had to steer a car along an obstacle-lined course
  • Drive a utility vehicle along a course
  • Climb an 8ft-high (2.4m) ladder
  • Remove debris blocking a doorway
  • Pull open a lever-handled door
  • Cross a course that featured ramps, steps and unfastened blocks
  • Cut a triangular shape in a wall using a cordless drill
  • Close three air valves, each controlled by a different-sized wheel or lever
  • Unreel a hose and then screw its nozzle into a wall connector

More than 100 teams originally applied to take part, and the number was whittled down to 17 by Darpa ahead of Friday and Saturday’s event.

Humanoid robots drove cars, climbed ladders – and often fell – in the competition sponsored by the US Department of Defense

Some entered their own machines, while others made use of Atlas – a robot manufactured by another Google-owned business, Boston Dynamics – controlling it with their own software.

One self-funded team from China – Intelligent Pioneer – dropped out at the last moment, bringing the number of contestants who took part at the Homestead-Miami Speedway racetrack to 16.

Schaft

Schaft’s liquid-cooled robot was able to carry out all of the eight main challenges it faced.

Schaft’s 1.48m (4ft 11in) tall, two-legged robot entered the contest the favourite and lived up to its reputation.

It makes use of a new high-voltage liquid-cooled motor technology thatuses a capacitor, rather a battery, for power. Its engineers say this lets its arms move and pivot at higher speeds than would otherwise be possible, in effect giving it stronger “muscles”.

Virginia Tech's Thor-OP
The robots had to attach a hose pipe as one of their challenges

The machine was developed by a spin-off from the University of Tokyo‘s Jouhou System Kougaku lab, which Google recently revealed it had acquired.

The team scored 27 points out of a possible 32, putting it seven points ahead of second-placed IHMC Robotics, which used Atlas.

Scores were based on a system that awarded three points for completing a task’s primary objectives, and then a bonus point for doing so without any human intervention.

Schaft’s robot behaved nearly perfectly, but lost points because “the wind blew a door out of their robot’s hold and because their robotic creation was not able to climb out of a vehicle after it successfully navigated an obstacle course,”reported the Japan Daily Press.

‘Reality check’

Videos posted online by Darpa illustrate that the robots remain much slower than humans, often pausing for a minute or more between actions while they carried out the calculations needed to make each movement.

Several proved unsteady on their feet and were only saved from falls by attached harnesses.

Three of the teams which entered self-designed machines – including Nasa’s Johnson Space Center and its robot Valkyrie – failed to complete any of the challenges.

The event was described as a “reality check” by Jyuji Hewitt, who attended on behalf of the US Army’s Research, Development and Engineering Command.

Robosimian
The robots – including Nasa’s Robosimian – were protected by harnesses on case they fell

But Darpa’s Mr Pratt added that the competition, and the finals that will be held in December, would help bring forward a time the machines could be used in real-world situations.

“Today’s modest progress will be a good next step to help save mankind from disasters,” he said.

The top eight teams can now apply for up to $1m (£611,000) of Darpa investment before the finals to improve their robots’ skills. The winner will get a $2m prize.

Lower scorers in last weekend’s round can stay in the contest but will have to fund their own efforts,

Man flu is no myth say scientists, with ‘manly’ men more susceptible

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Man flu may not be a myth after all, as scientist have found that men with high levels of testosterone have a hidden flaw – weak immune systems.

The discovery could explain why men are more susceptible than women to a whole range of bacterial, viral, fungal and parasitic infections, researchers said.

It may also be the reason why men’s immune systems respond less strongly to vaccinations against influenza, yellow fever, measles and hepatitis, along with many other infectious diseases.

Those who take testosterone supplements in the quest to gain muscle meanwhile, could be making themselves more susceptible to illness.

“This is the first study to show an explicit correlation between testosterone levels, gene expression and immune responsiveness in humans,” said US lead scientist Professor Mark Davis, from Stanford University.

“It could be food for thought to all the testosterone-supplement takers out there.”

The researchers studied how the immune systems of 34 men and 53 women were stimulated by the flu vaccine.

The jab generated a bigger boost in protective antibodies in women, with further analysis revealing activity that, in high testosterone men, was associated with a weakened antibody response. Men with low testosterone were not affected the same way.

Testosterone’s anti-inflammatory properties may explain why it can weaken the immune system, said scientists writing in the journal Proceedings of the National Academy of Sciences.

Prof Davies said the reason why testosterone weakens the immune system yet boosts muscle power and aggression, may be linked to the man’s evolutionary role.

Men are more likely than women to suffer injuries from competitive encounters, as well as their traditional roles of hunting, defence and potentially dangerous physical work, Prof Davies said. The dampening down the immune system makes male less susceptible to a potentially fatal over-reaction to infections, especially those from wounds.

“Ask yourself which sex is more likely to clash violently with, and do grievous bodily harm to, others of their own sex,” Prof Davis added.

Why are venomous organisms like snakes unaffected by their own venom?

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Photo: M. Periasamy

Usually venoms act by binding to the receptors present on the surface of the muscle cells on the victim thereby blocking the communication between the nerve cells and muscle cells in the victim.

When the toxin is already bound to the receptor, the natural neurotransmitter acetylcholine can no longer bind to the receptor as there were no free receptors left available by the toxins present in the venom. This blockage cause paralysis in the victim and in the worst case leads to death based on the nature of the venom. The receptors present on the mice and the humans are different from that of the venomous creatures like snakes. This difference prevents the venomous creatures’ venom binding to its receptors.

In snakes, sugar molecules cover the amino acid residues of the receptors thus protecting the binding of its own venom. However, the amino acid residues on the receptors are the same in the all the organisms only the clouding of the residues by sugar molecules make the venomous organisms resistant to their own venom.

Researchers have found that only two groups of animals, snakes and mongooses have sugar molecules on their receptors. The different types of venom attack different tissues in different ways, so a species of snake can ever become completely immune to the venoms of every other species of venomous snakes found in nature. Snakes are immune to the venom that most species of their own species. For example, in an attempt to stimulate or resist copulation, snake species bite one another during sexual combat. Snakes engage in sexual combat display immunity to the venom of their own species which is a must for their survival.

Other mechanisms that are protective for the snakes are as follows: Venom glands of the snakes make venom and specialized cells lining the venom gland protect the venom getting into their blood stream. As long as the venom does not get into the blood stream, it is safe for the animal.