Day: 06/13/2013

How the heart reacts at 200mph.

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How does the human heart react to the most extreme forms of stress?

Using sports science technology, three very different riders at the International North West 200 motorbike festival, put this question to the test.

With top speeds hitting 208mph, on closed public roads around the coast of Northern Ireland, the North West 200 is one of the fastest road races in the world. The motorbikes are often just inches from each other.

Three competitors were fitted with a heart strap and wireless sensor to measure their heart rate over every inch of the course.

The riders were ‘the Champion’ Alastair Seeley, 33, ‘the Novice’ Gareth Keys, 22, and ‘the Veteran’ Jeremy McWilliams, 49.

heart

Heart stress

The average adult heart:

  • Beats 72 times a minute
  • 100,000 times a day
  • 2.5 billion times in a lifetime
  • Weighs 250-350 grams
  • Pumps over 9,000 litres of blood through 60,000 miles of blood vessels every day
  • Is made of cardiac muscle, which never tires

Dr Sean Roe, from the Centre for Biomedical Science Education at Queen’s University Belfast, explains what causes the heart stress and some of the factors that influence the results.

“The heart is controlled largely by two centres in the brain,” said Dr Roe.

“The sympathetic ‘fight or flight’ response or the parasympathetic ‘rest and digest’ response.

“On occasions that require extra cardiac output the sympathetic nervous system kicks in, which speeds up the heart. Cardiac output, which is the amount of blood put out by the heart every minute, increases allowing the additional demands to be met.

“Alternatively when someone is relaxing, the parasympathetic nervous system is to the fore, reducing cardiac output by reducing heart rate, and increasing blood flow to the digestive system, taking it away from the muscles.

“Anything that increases fight or flight, such as exercise or emotional stress, will increase stress on the heart.”

Harder, faster, stronger

 

Cardiac function is related to fitness and age. The better your heart is at pushing blood around the body, the less relative stress it will be under when your heart rate goes up.

Dr Roe explained how exercise can help the heart cope with stress.

“One of the effects of training is to increase the volume of cardiac chambers. To increase cardiac output a certain amount, a fit heart would need to increase heart rate only a small amount compared to an unfit heart, because the fit heart is pumping more with each beat.”

He considers emotional stress to be among the main factors increasing heart rate for competitors in road racing.

“How stressful you interpret the situation to be would contribute to how fast your heart rate goes,” he said.

The results

Results of the heart rate test were taken on each of the rider’s first laps of evening racing, when the competitors had to battle difficult conditions after a typical torrential downpour at the North West 200.

The Champion, Alastair Seeley, had the lowest heart rate, with an average beats per minute (bpm) of 134, which is 71% of his maximum heart rate. There were minimal ‘spikes’ (moments of sharply increased output) throughout the lap.

Dr Roe was impressed by such a low, consistent heart rate.

The heart under stress

  • Body goes into ‘fight or flight’ mode
  • Brain releases adrenaline and cortisol
  • Heart rate rises
  • Blood flow increases – raising blood pressure
  • Fatty acids and glucose are released into the bloodstream for energy

“The Champion clearly didn’t perceive the situation as stressful. He is an ‘ice man’. An average bpm of 134 equates to a brisk walk for most people, and his breathing techniques may well have helped him.”

By contrast, the Novice, Gareth Keys, had an average heart rate of 185bpm.

“That is the equivalent of Sir Bradley Wiggins climbing Alpe d’Huez in the Tour de France. Such is the level of physiological stress… we calculated it as 94% of his maximum heart rate. This indicates a very large physiological stress stemming from his perception of the situation being quite threatening,” said Dr Roe.

The Veteran, Jeremy McWilliams, is somewhere in between the two riders, with an average heart rate of 164 bpm.

“The Veteran has the experience of having been there and done that, taking away some of the emotional stress. But an average heart rate 164bpm is 96% of his maximum heart rate.”

What makes road racers risk life and limb on motorbikes at speeds in excess of 200mph?

No matter how meticulously a rider prepares it is impossible to cover every eventuality. There is a thrilling unpredictability to road racing and this race was no exception.

The Novice was faced with a dog running out in front of him, causing his bpm to peak at 204bpm, while the Veteran had to contend with a fellow rider coming off his bike at high speed just metres in front of him, resulting in a huge spike of 220bpm.

Good core muscular strength is vital in road racing.

“A rider’s core muscles have to withstand the forces of acceleration and braking and after a number of laps those muscles get tired. Tired muscles are harder to control and can lead to more mistakes later in the race,” said Dr Roe.

Minimising the risk of mistakes is imperative in a road race, where the slightest error can have serious, even fatal, consequences. Dr Roe puts the risk road racers take in stark terms.

“Human reaction time is between 150 and 300 milliseconds. If a rider is travelling at 200mph, he is travelling 90 metres per second. In the one-fifth of a second he takes to react, he will have travelled about 18 metres. This means that if anything unexpected happens within 20 metres of a rider, a high speed collision can be unavoidable.”

Preparing for the unexpected

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We all know it’s a dangerous sport and we accept that. The danger element is the reason I do it.”

Guy Martin,

Road racer

“It is important to train to certain zones to be within 160, 170, 180 beats per minute. Train your heart to the particular zone you’re going to be in when you’re racing,” explained Alastair Seeley, who won the feature Superbike race at the North West 200 in 2012.

Many competitors also ride motocross bikes in deep sand during the winter to prepare themselves for the physical rigours of road racing.

Gio Capello, a strength and conditioning coach who worked with Seeley, explained the benefits of carefully tailored training.

“During races, a rider’s heart can get up to 180bpm at certain points so you want to develop more capacity to cope with those rates. We worked with Alastair on improving his aerobic fitness and increasing his VO2 max [the volume of oxygen you can consume while exercising at your maximum capacity].”

Psychological pressure

The Veteran is adamant that stress and pressure are always there in the build-up to a race.

“That’s the side of racing that’s not pleasant, the nervous energy, not knowing what’s around the corner. Once the flag drops it becomes so much easier, all of that is gone.”

The Novice prepares for the race by attempting to blank everything out and focus on the task ahead.

“I’ll spend about a minute alone with the bike just thinking about who’s in front of me and stay as calm as I can.”

The Champion explains how there are practical steps a rider can take during the race to keep their heart rate down.

“Round the coast road section of the North West 200, it’s quite busy and sometimes you maybe hold your breath for that bit too long, which then upsets the rhythm of the heart. But once I get on the big straights here I consciously take some big gulps of air and calm myself down again.”

Life at 200mph

Despite the many factors that influence cardiac performance at high speeds, perhaps the most important thing for any road racer to have in their hearts is a love of the sport. Without this, it’s unlikely they would take on such big risks at such high speeds.

Guy Martin, a regular rider at road racing events, said the risk factor goes some way to explaining the sport’s attraction: “We all know it’s a dangerous sport and we accept that. Probably the danger element is the reason I do it – I like the buzz.”

Source: BBC

 

What would big data think of Einstein?

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A friend of mine recently remarked on the uncanny ability of Netflix to recommend movies that he almost always finds interesting. Amazon, too, barrages email inboxes with book recommendations, among other things. Indeed, the entire advertising industry has been transformed by its ability to use data to target individual consumers in ways unimaginable in the Mad Men era.

The power of big data goes far beyond figuring out what we might want to know. Big data helps pharmaceutical companies identify the attributes of their best sales people, so they can hire, and train, more effectively. Big data can help predict what songs are likely to be hits, which wine vintages will taste better and whether chubby baseball pitchers have the right stuff.

But big data should not be confused with big ideas. It is in those ideas — the ones that make us conjure up the image of Albert Einstein — that lead to breakthroughs.

The benefits of big data are so, well, big, that there’s no going back. Yet I don’t need to re-read George Orwell, or scan the latest headlines about the massive snooping of personal communications orchestrated by theNational Security Agency in the United States to feel at least some discomfort with big data’s side effects. One that seldom gets notice: in a world where massive datasets can be analysed to identify patterns not easily identified using simpler analogue methods, what happens to genius of the Einstein variety?

Genius is about big ideas, not big data. Analysing the attributes and characteristics of anything is guaranteed to find some patterns. It is inherently a theoretical exercise, one that requires minimal thought once you’ve figured out what you want to measure. If you’re not sure, just measure everything you can get your hands on. Since the number of observations — the size of the sample — is by definition huge, the laws of statistics kick in quickly to ensure that significant relationships will be identified. And who could argue with the data?

Companies, like civilisations, advance by leaps and bounds when genius is let loose, not when genius is locked away and deemed too out of the mainstream of data-driven knowledge.

Unfortunately, analysing data to identify patterns requires you to have the data. That means that big data is, by necessity, backward-looking; you can only analyze what has happened in the past, not what you can imagine happening in the future. In fact, there is no room for imagination, for serendipitous connections to be made, for learning new things that go beyond the data. Big data gives you the answer to whatever problem you might have (as long as you can collect enough relevant information to plug into your handy supercomputer). In that world, there is nothing to learn; the right answer is given.

I like right answers as much as the next guy, but in my experience those answers are just not enough to motivate people to action. For instance, knowing that email follow-ups to sales calls are the most time efficient is nice, but that fact is unlikely to convince a salesperson who has always picked up the phone to change his approach, especially if his approach has always worked for him.

People don’t think in the same way that data behaves. They need to be convinced, they want to be part of the creation of the solution. They don’t like the solution to be imposed on them. You can have all the “optimal” solutions you like, but in the real world managers need to convince other people to execute on those solutions. And people have a habit of wanting to contribute to the development of the solutions.

In business, big data doesn’t necessarily drive out creativity; it’s just that its scientific imprimatur makes it very hard to argue the opposite way. Yes, it is possible for creative people to start further down the field when they have a deeper understanding of the underlying relationships that govern their discipline. Advertisers can design better campaigns if they truly understand what consumers are buying and why. But sometimes you need to break the rules to create anything new. Apple’s original iPod was such a hit precisely because it emphasised simple and elegant design features rather than what everyone else was competing on — MP3 sound quality.

Just as companies that build their business on “best practice,” ensure that they will never do more than anyone else, companies that let big data dominate their thinking and management style will not be the ones who change the rules of the game in their industry. Even in the leading repository of big data thinking — Silicon Valley — how many start-ups have taken form specifically to capitalise on big data insights? Not Facebook, not Google, and definitely not Apple. These companies actively leverage big data to grow their businesses, but the spark that led to their creation was personal, entrepreneurial and even idiosyncratic.

The inability to understand or capture the human element — that personal, even idiosyncratic, thinking that drives genius — in business is the biggest danger that comes from big data. Has there ever been a major breakthrough whose origin doesn’t reside in the brain of a man or a woman? Imagine in the not-too- distant future a brilliant person, a genius, proclaiming a new way of thinking that is contrary to big data. What would happen to her ideas if she bucked the orthodoxy of big data to suggest a different view of the world not consistent with the dominant digitally derived solution? We might lock up her ideas. If anyone paid attention to what she said, she would be denounced as uninformed.

Companies, like civilisations, advance by leaps and bounds when genius is let loose, not when genius is locked away and deemed too out of the mainstream of data-driven knowledge.

What if Albert Einstein lived today and not 100 years ago? What would big data say about the general theory of relativity, about quantum theory? There was no empirical support for his ideas at the time — that’s why we call them breakthroughs.

Today, Einstein might be looked at as a curiosity, an “interesting” man whose ideas were so out of the mainstream that a blogger would barely pay attention. Come back when you’ve got some data to support your point.

Source:BBC

 

 

 

 

 

Does coffee really sober you up when drunk?.

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A few years ago I went to a play at my local theatre with some friends. My husband arrived late and a little jolly, having been to his office Christmas lunch and spent most of the afternoon drinking wine. Luckily it was a comedy, but he laughed so much that even the cast looked surprised at his enthusiasm.

During the interval I bought him a coffee to help sober him up before the second act. By the end of the play he was a bit quieter, but was I right to assume it was the coffee that had done the trick?

coffee

The sedative effects of large quantities of alcohol are well-established. For the first hour-and-a-half or so, when blood-alcohol concentrations are high, people become more alert. From two hours after alcohol consumption to around six hours, objective measures of sleepiness increase . Caffeine does the opposite, making people more alert, which has led to the appealing idea that a cup of coffee can cancel out the effects of a pint of beer.

Sadly it’s not that straightforward. Historically, studies of the effect of caffeine on people’s driving abilities when drunk (in the lab, not on the roads) have had contradictory results. Some have found it reverses the slowing of reaction times caused by alcohol, others have found it doesn’t.

More recently, a study published in 2009 was designed to tease out in more detail the effects of combining alcohol and caffeine. Mice were given alcohol followed by the human equivalent of eight cups of coffee. After the caffeine they seemed more alert, but they were still much worse than sober mice at getting round a maze.

So caffeine can counteract the tiredness induced by alcohol, which might explain why a cup of coffee is popular in many places at the end of a meal. But it can’t remove feelings of drunkenness or some of the cognitive deficits alcohol causes. The reason is that we have to metabolise the alcohol we drink in order to diminish its effects. The body processes it in several ways. Mostly it’s broken down in the liver by two enzymes, alcohol dehydrogenase and aldehyde dehydrogenase. After several steps the alcohol is eventually excreted as water and carbon dioxide.

It takes approximately an hour for the body to metabolise one unit of alcohol, although some people do it faster and some slower, depending on their genetic make-up, how much food they’ve eaten and how often they drink. Caffeine doesn’t speed up the process. However its effects vary according to which function you’re looking at. One study, for example, found a large dose of caffeine can counteract the negative effects of alcohol on memory, but that feelings of dizziness remain.

There are also suggestions that caffeine can make matters worse. If you feel tired you are more likely to realise that you must be drunk, but if the caffeine takes away some of that fatigue you might believe you’re sober when you’re not. This might explain the findings of a study of American college students from 2008. Those who chose drinks containing both alcohol and caffeine, such as vodka and Red Bull, were twice as likely to get hurt in an accident and more than twice as likely to accept a lift with a driver who was over the limit. This effect was independent of the amount of alcohol consumed. This is an early study on the topic in which the students choose their own drinks and reported themselves how much they’d drunk. But it does illustrate how caffeine could fool people into thinking they’re sobering up, and some of the potentially disastrous consequences.

So if I go to a play on the day of my husband’s office party this year, I’ll know that only time will make a difference. I’ll have to hope it’s a production with a third act then.

Source: BBC

 

Does Death Exist? New Theory Says ‘No’.

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Many of us fear death. We believe in death because we have been told we will die. We associate ourselves with the body, and we know that bodies die. But a new scientific theory suggests that death is not the terminal event we think.

does_death_exist

One well-known aspect of quantum physics is that certain observations cannot be predicted absolutely. Instead, there is a range of possible observations each with a different probability. One mainstream explanation, the “many-worlds” interpretation, states that each of these possible observations corresponds to a different universe (the ‘multiverse’). A new scientific theory – called biocentrism– refines these ideas. There are an infinite number of universes, and everything that could possibly happen occurs in some universe. Death does not exist in any real sense in these scenarios. All possible universes exist simultaneously, regardless of what happens in any of them. Although individual bodies are destined to self-destruct, the alive feeling – the ‘Who am I?’- is just a 20-watt fountain of energy operating in the brain. But this energy doesn’t go away at death. One of the surest axioms of science is that energy never dies; it can neither be created nor destroyed. But does this energy transcend from one world to the other?

Consider an experiment that was recently published in the journalScience showing that scientists could retroactively change something that had happened in the past. Particles had to decide how to behave when they hit a beam splitter. Later on, the experimenter could turn a second switch on or off. It turns out that what the observer decided at that point, determined what the particle did in the past. Regardless of the choice you, the observer, make, it is you who will experience the outcomes that will result. The linkages between these various histories and universes transcend our ordinary classical ideas of space and time. Think of the 20-watts of energy as simply holo-projecting either this or that result onto a screen. Whether you turn the second beam splitter on or off, it’s still the same battery or agent responsible for the projection.

According to Biocentrism, space and time are not the hard objects we think. Wave your hand through the air – if you take everything away, what’s left? Nothing. The same thing applies for time. You can’t see anything through the bone that surrounds your brain. Everything you see and experience right now is a whirl of information occurring in your mind. Space and time are simply the tools for putting everything together.

Death does not exist in a timeless, spaceless world. In the end, even Einstein admitted, “Now Besso” (an old friend) “has departed from this strange world a little ahead of me. That means nothing. People like us…know that the distinction between past, present, and future is only a stubbornly persistent illusion.” Immortality doesn’t mean a perpetual existence in time without end, but rather resides outside of time altogether.

This was clear with the death of my sister Christine. After viewing her body at the hospital, I went out to speak with family members. Christine’s husband – Ed – started to sob uncontrollably. For a few moments I felt like I was transcending the provincialism of time. I thought about the 20-watts of energy, and about experiments that show a single particle can pass through two holes at the same time. I could not dismiss the conclusion: Christine was both alive and dead, outside of time.

Christine had had a hard life. She had finally found a man that she loved very much. My younger sister couldn’t make it to her wedding because she had a card game that had been scheduled for several weeks. My mother also couldn’t make the wedding due to an important engagement she had at the Elks Club. The wedding was one of the most important days in Christine’s life. Since no one else from our side of the family showed, Christine asked me to walk her down the aisle to give her away.

Soon after the wedding, Christine and Ed were driving to the dream house they had just bought when their car hit a patch of black ice. She was thrown from the car and landed in a banking of snow.

“Ed,” she said “I can’t feel my leg.”

She never knew that her liver had been ripped in half and blood was rushing into her peritoneum.

After the death of his son, Emerson wrote “Our life is not so much threatened as our perception. I grieve that grief can teach me nothing, nor carry me one step into real nature.”

Whether it’s flipping the switch for the Science experiment, or turning the driving wheel ever so slightly this way or that way on black-ice, it’s the 20-watts of energy that will experience the result. In some cases the car will swerve off the road, but in other cases the car will continue on its way to my sister’s dream house.

Christine had recently lost 100 pounds, and Ed had bought her a surprise pair of diamond earrings. It’s going to be hard to wait, but I know Christine is going to look fabulous in them the next time I see her.

Source: BBC

 

Birdsong phone apps ‘harmful’ to birds, say Dorset experts.

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The “harmful misuse” of mobile phone apps that mimic birdsong can stop birds performing important tasks such as feeding their young, experts have said.

_68123154_nightjarstevedavis

Dorset Wildlife Trust said visitors to Brownsea Island were using apps to imitate Nightjar calls to entice birds out so they could photograph them.

The RSPB said birds could be diverted from vital tasks and said people might be “devastated” if they realised.

Hilary Wilson, from developer iSpiny, said the apps were a learning tool.

“We welcome this discussion into the ethics of using recorded songs,” she said.

‘No respect’

Brownsea Island nature reserve manager Chris Thain said: “Use of these apps is not suitable for nature reserves and can be potentially harmful to sensitive species.”

Tony Whitehead, public affairs officer for the RSPB in the South West said: “Repeatedly playing a recording of birdsong or calls to encourage a bird to respond in order to see it or photograph it can divert a territorial bird from other important duties, such as feeding its young.

“It is selfish and shows no respect to the bird. People should never use playback to attract a species during its breeding season.”

Mr Thain added: “The apps are becoming quite common, and are great, but their use needs some guidance I feel.

“I’m sure visitors would be devastated if they realised the possible disturbance they were causing to wildlife.”

Dr Wilson, who oversees the Chirp! app for iSpiny and said the firm was the UK’s leading developer of apps about birds and bird song, said: “Our apps aim to assist in learning and identifying bird songs and calls but we realise that they may be used to encourage birds to respond.

“We urge great caution – birdsong is simply a pleasant sound to human ears, but to birds it is a powerful means of communication… the issue with recordings is simple – out of consideration for both the birds and fellow birdwatchers, just keep the volume low.”

Nesting birds are protected under The Wildlife and Countryside Act 1981, which states it is an offence to intentionally disturb them.

Brownsea Island, which now has signs warning visitors about phone app use, has Special Protection Area status for the habitats it provides for birds, including the Nightjar.

The species’ habitats have seen a recent recovery in the county.

Source: BBC

 

Asian tigers at risk from domestic dog distemper virus.

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Some of the world’s rarest big cat species are facing a potentially deadly threat from a virus carried by domestic dogs, a wildlife expert has warned.

John Lewis, director of Wildlife Vets International, said there was evidence that Indonesian tigers were at risk.

lion

Canine distemper virus has evolved in recent decades from infecting only dogs to affecting other animal groups.

Dr Lewis plans to work with Indonesian vets to develop a strategy to protect the nation’s tigers from the virus.

A close relative of measles, Canine distemper virus (CDV) was first described at the beginning of the 20th Century and has been cited as contributing to the demise of the thylacine (commonly known as the Tasmanian tiger as a result of the black stripes on its back).

“If you wind the clock back about 30 or 40 years, it was a dog disease – it was a canine virus and only affected dogs,” Dr Lewis explained.

“But in the intervening years, the virus has evolved and has changed its pattern of animals it can infect to include marine mammals (such as seals) and big cats.”

Reservoir dogs

He told BBC News that CDV needed a reservoir, like a population of dogs, to remain effective as a pathogen.

Anecdotal evidence suggests CDV is already affecting critically endangered Sumatran tigers

These conditions were present when the first case of the disease affecting wild big cats was documented, he recalled.

“In the mid-1990s, in the Serengeti, Africa, about 30% of the lions died from CDV, which came from dogs in surrounding villages.

“It has also been recognised in the Asian big cat populations,” he added.

“Since 2000, in the Russian Far East, there have been a few cats reported as behaving strangely and coming into villages, apparently not showing much fear towards people.

“In the past few years, tissue from at least a couple of those cats have now been confirmed as showing the presence of CDV infection.

“There have not been too many cases at the moment, we think about three or four, but we think there could have been more that have gone undiagnosed.”

While some tigers appear as if they are able to build up a reasonable immunity response, most of the animals do succumb to the disease if they are exposed to the virus.

Dr Lewis explained that symptoms manifested themselves in a number of ways:

 “Start Quote

The big threats facing tigers is habitat loss and degradation and poaching, but I think the third big threat now is likely to be disease”

Dr John LewisWildlife Vets International

“Some will die as a result of respiratory problems, such as pneumonia for example.

“Some will have neurological problems, such as losing the fear of people or having seizures.”

But, he added: “We do not have enough information on CDV in tigers to know what percentage go on to die; we just have a little bit of data from zoos and a little bit of data from the wild.

“There are a lot of cases of distemper in the region and tigers are partial to eating dogs.

“For a tiger to take a dog on the periphery of a village is not usual at all, so you do have the circumstances that would bring tigers into contact with CDV.”

Although it was assumed the cause of CDV infection in tigers was a result of coming into contact with dogs carrying the virus, Dr Lewis said that a research project was under way to look at the source of CDV in Amur tigers (also known as Siberian tigers) in the Russian Far East.

Worrying signs

The behaviour change in tigers was particularly worrying, Dr Lewis observed.

“This puts them at big risk because they lose their fear of poachers or they bring themselves in situations of conflict, such as playing with traffic.”

On a recent visit to the Indonesian island of Sumatra, he said conversations with local wildlife vets seemed to indicate that CDV could already be present in the population of the critically endangered Sumatran tiger.

They told him that they had seen strange behaviour displays by tigers, such as the big cats coming into villages and losing their fear of people.

“To me, that suggests that distemper is already beginning to have an impact on tigers in Sumatra,” he warned.

“But before you say ‘yes, that is definitely the result of CDV’, you need diagnostic testing of brain tissue.

“The big threats facing tigers are habitat loss and degradation and poaching, but I think the third big threat now is likely to be disease, particularly one like CDV.”

The Sumatran tiger is only found on the island and population estimates suggest that there are fewer than 700 left in the wild, of which only 40% are viable mature individuals.

Dr Lewis is returning to Sumatra in September to bring together all the vets from all the different areas that come into contact with tigers.

“The goal is to thrash out a very simple way of deciding what samples need to be taken from all tigers that are handled by humans throughout Sumatra, in order to help us with diagnostics,” he explained.

“We also need to thrash out what samples need to be taken from domestic dog populations.

“We need to work out where we can send these samples for laboratory testing. We need to work out how we are going to store and move these samples.

“Once we have got that nailed down then we start work and try to design some sort of mitigation strategy, and that won’t be easy.”

Source: BBC

 

Decoding the secrets of dolphins’ language

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Humans have a strong affinity with dolphins. The marine mammals are regarded as one of the world’s most intelligent species, travelling in pods which display complex hierarchies and group cultures.

dolphin

Behavioural biologist Dr Denise Herzing has spent the last 25 years trying to find out what makes dolphins tick – studying their social structure and behaviour in the wild, and attempting to decode the body language and intricate sounds dolphins use to communicate with each other.

Do dolphins have a language? What are they saying? And could we one day learn it? Derzing explains how dolphins may be saying a lot more than we give them credit for.

Source: BBC

 

 

Black hole caught napping after meal.

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A black hole 11 million light-years away has gone dormant, a decade after being spotted consuming cosmic debris.

The black hole lies at the centre of the Sculptor galaxy, a so-called starburst galaxy where stars are being born at a prodigious rate.

black

But the X-ray light corresponding to a black hole’s snack has dimmed markedly.

The find, to appear in Astrophysical Journal, has mystified astronomers because star formation and black hole activity tend to go hand-in-hand.

The Sculptor galaxy – also known as NGC 253 – hosts a central black hole with a mass some five million times that of our Sun – a quarter again as plump as the black hole at the centre of our own Milky Way galaxy.

In 2003, researchers using the Chandra space telescope caught sight of the X-rays that correspond to matter spiralling down into the black hole and heating up to millions of degrees.

But as of mid-2012, the X-ray sky has a new observer: a space telescope called the Nuclear Spectroscopic Telescope Array or Nustar,already a successful black-hole hunter.

Nustar can spot even higher-energy X-rays than Chandra, and in late 2012, both telescopes were trained on NGC 253 – with the surprise finding that the X-ray emission seems to have stopped.

“Black holes feed off surrounding accretion disks of material. When they run out of this fuel, they go dormant,” said Ann Hornschemeier of Nasa’s Goddard Space Flight Center, a co-author on the new study.

“NGC 253 is somewhat unusual because the giant black hole is asleep in the midst of tremendous star-forming activity all around it.”

The subtle interplay between black hole activity and the birth rate of new stars remains somewhat mysterious, but Bret Lehmer of Nasa’s Goddard Space Flight Center, lead author on the paper, said that the Sculptor galaxy could shed new light on these dark galactic corners.

“Periodic observations with both Chandra and Nustar should tell us unambiguously if the black hole wakes up again. If this happens in the next few years, we hope to be watching,” he said.

Source:BBC

 

 

Cheetah tracking study reveals incredible acceleration.

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The fastest animal on land rarely uses its top speed to capture prey, according to a new analysis.

A study of cheetahs has shown that instead, the animal uses incredible acceleration and rapid changes in speed when hunting.

_68135418_c0157806-cheetah_running,_native_to_africa-spl

The animals get this acceleration by exerting nearly five times more power than that of famed sprinter Usain Bolt during his record-breaking 100m run.

The results are published in the journal Nature.

The findings amazed the scientist who led the research, Prof Alan Wilson of the Royal Veterinary College in Hatfield, UK.

“They are remarkable athletes – not just in terms of their speed, but also with their ability to accelerate and manoeuvre in capturing the prey,” he told BBC News.

The top speed for a cheetah is often quoted is 65mph (105km/h) – a result measured in 1965 and published in the Journal of Zoologythree decades later by a scientist in Kenya. He was timing the run of a semi-domesticated cheetah running in a straight line on a firm dirt track.

But a well-fed zoo cheetah is not accustomed to running very fast – it does not need to. As a result, few measurements of zoo cheetahs found speeds greater than that of a greyhound, about 40mph (64km/h).

So for years, researchers wondered whether cheetahs might run much faster than 65mph in the wild in order to capture prey.

Rapid acceleration

Prof Wilson and his team at the college’s Structure and Motion Laboratory decided to find out by following five animals in the wild for a year using tracking collars fitted with movement detectors and GPS systems.

They found that the cheetahs did indeed run very fast at times – close to 60mph – but only occasionally. On most hunts they attained about 30 to 35 mph but they were accelerating and changing direction much more rapidly than has been seen in any other land animal.

For sprinters and predators, speed is not the only variable for success – acceleration counts

They found that cheetahs could increase their speed by nearly 7mph (10km/h) in a single stride.

“They’ve arranged to have a low gear so they can accelerate very rapidly up to their top speed,” said Prof Wilson.

Short bursts of speed can be quantified in power per kilogramme of the animal’s weight. Jamaican sprinter Usain Bolt exerted 25 W/kg during his record-breaking run in 2009.

A horse used in a polo match exerts slightly more power per kg, around 30 W/kg, and a greyhound’s is double that at 60 W/kg. But a cheetah can reach 120 W/kg.

The researchers also found that cheetahs also have a very strong grip, so much so that they rip up the ground as they run. They found it was the use of the animals’ claws that enabled them to turn very sharply and to accelerate and decelerate very quickly.

The measurements have only been made possible because of the collars that have been developed by Prof Wilson specifically for the experiment.

“It is very hard for GPS to work on an animal that is ducking and diving, so the collar is an innovation in its own right,” he said.

“We’ve been working on GPS for 12 years and the collars are the result of those labours. They are not your typical GPS tracking system that you get in the car or phone.

“The GPS is far more accurate we are getting positions and speeds five times a second. We combine those with readings from other instruments and we finish up with something that is very much more accurate both in terms of speed and position and very much more robust,” Prof Wilson explained.

The team are currently using the collars to track lions and African wild dogs to obtain comparative measurements.

Source:BBC

�h0t���  � ily:”Arial”,”sans-serif”;color:#333333′>”We are in a different era; quite frankly the bees haven’t got the resistance and reserves that they once did because of various illnesses and viruses,” said Mr Davies, who himself lost around a quarter of his 25 colonies.

 

The weather also posed problems for newly emerged queen bees – “virgin queens”. The growth of colonies depends on these bees being able to mate properly so they can lay fertilised eggs. But the poor weather hampered these activities as well.

If the weather is changeable, a queen may not execute her mating flight properly, Tim Lovett from the British Beekeepers Association told BBC News.

“If she doesn’t get properly mated she can only lay drones, and if she is doing that, that’s the death knell for the hive.”

A colony that has only drones and no workers will not survive.

Another weather-related factor that has worked against the bees is what is called isolation starvation. Because of the cold, the bees cluster very closely together to maintain hive temperature and consume the stores of honey closest to them.

If the weather is so cold that they can’t actually move, the bees will starve – although there may be plenty of food sources nearby.

Beekeepers say that is very bad news for honey supplies in the coming months. Late last year, the British Beekeepers’ Association reported that the honey crop was down by over 70% compared to 2011. They do not have great hopes for a recovery this year.

“It’s disastrous for honey production,” said Mr Lovett. “There is a cumulative effect because you have got to replace those hives. That is something the beekeeper now has to do.

“This loss of bees was in effect far more dramatic than foot-and-mouth was on the national beef herd. It means a great deal of work ahead for beekeepers to get back to where they were.”

Source: BBC

 

Honey bee losses double in a year due to poor winter.

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This winter’s losses of honey bee colonies were the worst since records began six years ago, according to a survey carried out by the British Beekeepers Association.

It says more than a third of hives did not survive the cold, wet conditions.

All regions of England saw dramatic declines with the numbers lost more than double the previous 12 months.

This year’s poor winter, following on from a disastrous summer, is said to be the main reason for the losses.

British beekeepers have been surveyed at the end of March for the last six years.

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This loss of bees was in effect far more dramatic than foot and mouth was on the national beef herd”

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Tim LovettBritish Beekeepers Association

They are asked to compare the number of colonies that are still alive compared to the numbers they had back in October.

With overall losses at 33.8%, this year’s figures are the worst yet recorded.

The hardest hit region was the South West where over half of the hives were lost.

“It is desperate; it is a huge loss of bees,” Devon beekeeper Glyn Davies told BBC News.

“The weather last summer and this winter, the two combined meant there was virtually a whole year when bees were confined and stressed just because of the environmental conditions.”

Queens affected

The bad weather meant that honey bees were unable to get out and forage. There was a scarcity of pollen and nectar throughout the season.

Some beekeepers believe that the increased number of infections and disease that bees are subject to may have made them weaker and unable to cope with the colder conditions.

“We are in a different era; quite frankly the bees haven’t got the resistance and reserves that they once did because of various illnesses and viruses,” said Mr Davies, who himself lost around a quarter of his 25 colonies.

The weather also posed problems for newly emerged queen bees – “virgin queens”. The growth of colonies depends on these bees being able to mate properly so they can lay fertilised eggs. But the poor weather hampered these activities as well.

If the weather is changeable, a queen may not execute her mating flight properly, Tim Lovett from the British Beekeepers Association told BBC News.

“If she doesn’t get properly mated she can only lay drones, and if she is doing that, that’s the death knell for the hive.”

A colony that has only drones and no workers will not survive.

Another weather-related factor that has worked against the bees is what is called isolation starvation. Because of the cold, the bees cluster very closely together to maintain hive temperature and consume the stores of honey closest to them.

If the weather is so cold that they can’t actually move, the bees will starve – although there may be plenty of food sources nearby.

Beekeepers say that is very bad news for honey supplies in the coming months. Late last year, the British Beekeepers’ Association reported that the honey crop was down by over 70% compared to 2011. They do not have great hopes for a recovery this year.

“It’s disastrous for honey production,” said Mr Lovett. “There is a cumulative effect because you have got to replace those hives. That is something the beekeeper now has to do.

“This loss of bees was in effect far more dramatic than foot-and-mouth was on the national beef herd. It means a great deal of work ahead for beekeepers to get back to where they were.”

Source: BBC