Everything You Need to Know About Turbulence

Everything You Need to Know About Turbulence | eklectica.in
Turbulence: spiller of coffee, jostler of luggage, filler of barf bags, rattler of nerves. But is it a crasher of planes? Judging by the reactions of many airline passengers, one would assume so; turbulence is far and away the number one concern of anxious passengers. Intuitively, this makes sense. Everybody who steps on a plane is uneasy on some level, and there’s no more poignant reminder of flying’s innate precariousness than a good walloping at 37,000 feet. It’s easy to picture the airplane as a helpless dinghy in a stormy sea. Boats are occasionally swamped, capsized, or dashed into reefs by swells, so the same must hold true for airplanes. Everything about it seems dangerous.

Except that, in all but the rarest circumstances, it’s not.

Source: Turbulence: Everything You Need to Know, Part 1




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Modern medicine: Microbes maketh man

POLITICAL revolutionaries turn the world upside down. Scientific ones more often turn it inside out. And that, almost literally, is happening to the idea of what, biologically speaking, a human being is.

The traditional view is that a human body is a collection of 10 trillion cells which are themselves the products of 23,000 genes. If the revolutionaries are correct, these numbers radically underestimate the truth. For in the nooks and crannies of every human being, and especially in his or her guts, dwells the microbiome: 100 trillion bacteria of several hundred species bearing 3m non-human genes. The biological Robespierres believe these should count, too; that humans are not single organisms, but superorganisms made up of lots of smaller organisms working together.

It might sound perverse to claim bacterial cells and genes as part of the body, but the revolutionary case is a good one. For the bugs are neither parasites nor passengers. They are, rather, fully paid-up members of a community of which the human “host” is but a single (if dominating) member. This view is increasingly popular: the world’s leading scientific journals, Nature and Science, have both reviewed it extensively in recent months. It is also important: it will help the science and practice of medicine (see article).

All in this together

The microbiome does many jobs in exchange for the raw materials and shelter its host provides. One is to feed people more than 10% of their daily calories. These are derived from plant carbohydrates that human enzymes are unable to break down. And not just plant carbohydrates. Mother’s milk contains carbohydrates called glycans which human enzymes cannot digest, but bacterial ones can.

This alone shows how closely host and microbiome have co-evolved over the years. But digestion is not the only nutritional service provided. The microbiome also makes vitamins, notably B2, B12 and folic acid. It is, moreover, capable of adjusting its output to its host’s needs and diet. The microbiomes of babies make more folic acid than do those of adults. And microbiomes in vitamin-hungry places like Malawi and rural Venezuela turn out more of these chemicals than do those in the guts of North Americans.

The microbiome also maintains the host’s health by keeping hostile interlopers at bay. An alien bug that causes diarrhoea, for instance, is as much an enemy of the microbiome as of the host. Both have an interest in zapping it. And both contribute to the task. Host and microbiome, then, are allies. But there is more to it than that. For the latest research shows their physiologies are linked in ways which make the idea of a human superorganism more than just a rhetorical flourish.

These links are most visible when they go wrong. A disrupted microbiome has been associated with a lengthening list of problems: obesity and its opposite, malnutrition; diabetes (both type-1 and type-2); atherosclerosis and heart disease; multiple sclerosis; asthma and eczema; liver disease; numerous diseases of the intestines, including bowel cancer; and autism. The details are often obscure, but in some cases it looks as if bugs are making molecules that help regulate the activities of human cells. If these signals go wrong, disease is the consequence. This matters because it suggests doctors have been looking in the wrong place for explanations of these diseases. It also suggests a whole new avenue for treatment. If an upset microbiome causes illness, settling it down might effect a cure.

Yogurt companies and health-food fanatics have been banging this drum for years. And in the case of at least one malady, irritable-bowel syndrome, they are right. So-called probiotics, a mixture of about half a dozen bacterial species found in yogurt, do act to calm this condition. But there is little evidence that consuming probiotics has the tonic effect on healthy people that certain adverts suggest.

A handful of doctors are taking a more fundamental approach to another microbiome-related disease, infection with Clostridium difficile. This bacterium, which causes life-threatening distension of the gut in some people who have been treated with antibiotics and thus had their microbiomes disrupted, is a bane of hospitals. It kills 14,000 people a year in America alone. But recent experiments have shown it can be eliminated by introducing, as an enema, the faeces of a healthy individual. “Stool transplants” are a pretty crude approach, to be sure, but the crucial point is that microbes are much easier to manipulate than human cells. For all the talk of superorganisms (and despite the yuck factor of what is being moved from one body to another), transplanting a microbiome is far easier than transplanting a heart or a kidney.

Disgusting but useful

Two other areas look promising. One is more sophisticated deployment of the humble antibiotic, arguably the pharma industry’s most effective invention. At the moment antibiotics are used mainly to kill infections. In the future they might have a more subtle use—to manipulate the mix of bugs within a human, so that good bugs spread at the expense of bad ones.

The other field that may be changed is genetics. Many of the diseases in which the microbiome is implicated seem to run in families. In some, such as heart disease, that is partly explained by known human genes. In a lot, though, most notably autism, the genetic link is obscure. This may be because geneticists have been looking at the wrong set of genes—the 23,000 rather than the 3m. For those 3m are still inherited. They are largely picked up from your mother during the messy process of birth. Though no clear example is yet known, it is possible that particular disease-inducing strains are being passed down the generations in this way.

As with all such upheavals, it is unclear where the microbiome revolution will end up. Doctors and biologists may truly come to think of people as superorganisms. Then again, they may not. What is clear, though, is that turning thinking inside out in this way is yielding new insights into seemingly intractable medical problems, and there is a good chance cures will follow. Vive la révolution!

Source: Modern medicine: Microbes maketh man | The Economist

Sleep Your Way to the Top: How Sleep Equals Success

A growing number of research studies suggest that sleep may be the secret to performing at your highest level, writes David K. Randall. Everyone from the military to athletes are starting to get serious about sleep.

After struggling for almost a minute in a November debate to come up with the third federal agency he’d eliminate should he win the Oval Office, Texas Gov. Rick Perry finally admitted he couldn’t remember.

While his campaign quickly tried to limit the damage, there had been earlier signs that Gov. Perry was in trouble that had little to do with his campaign war chest, his policies, or his personal charisma. Instead, they had everything to do with his pillow.

“We had a tired puppy,” one of Perry’s Republican allies told The New York Times after the governor had performed poorly in a string of earlier debates. Aides tried to rework his schedule in order for Governor Perry to get more hours of slumber, but it apparently wasn’t enough before that November night.

For most of us, it’s easy to see the stumble as nothing more than a memorable gaffe. Yet Governor Perry’s moment of forgetfulness should also serve as the sum of all fears for anyone who sees sleep as something that can be put off or overlooked without painful consequences. When a person lies down to sleep at night, the brain undergoes a process that is crucial to learning, memory, and performance in ways that scientists are only now beginning to understand. Though the exact mechanisms of the brain remain unclear, studies have suggested that time spent dozing has helped research subjects solve puzzles faster, pick up new skills with better results, and think more quickly on their feet.

Why does sleep help turn us into more competent versions of ourselves? Part of the answer is the simple fact that chronic sleep deprivation, which for most of us means routinely getting six or less hours of sleep each night, essentially makes us feel and act like we’re drunk. This breakdown most likely affects you even if you think you can function without sleep and not suffer the consequences. There are some that can stay awake longer, of course, but they remain relatively rare: in 2009, researchers at UC–San Francisco identified an unusual genetic mutation that allowed members of one family to routinely go with less than six hours of sleep with no clear tradeoffs in ability or health.
Dreamland by David K Randall

‘Dreamland: Adventures in the Strange Science of Sleep’ By David K. Randall. 304 pages. W. W. Norton. $25.95. (George Coppock / Getty Images)

A study in the journal Occupational and Environmental Medicine published in 2000 applies to the rest of us. Researchers gathered a group of subjects that included employees at a transportation company and members of the Australian Army. Each person was tested on his or her ability to drive in a simulated road test. As subjects went without sleeping, their reaction times slowed, their memories dulled, and their sense of time grew hazy. Soon, it was clear that those who had stayed awake for more than 17 straight hours were in worse shape than those with a blood alcohol content of 0.05 percent, the level that qualified as legally drunk in Australia.

But sleep’s benefits aren’t simply preventing slowing reaction times. Sleep also looks to bolster the brain’s ability to handle taxing mental loads. This even applies to naps. Researchers at the City University of New York, for example, gave test subjects a pair of objects and told them that they would be judged on their ability to remember them later. One group was given a 90-minute break to take a nap, while the other group spent that time awake watching a movie. Subjects came back to the testing room expecting to complete the simple memory puzzle. Researchers instead asked them to describe the relationships between the objects that made up each pair, rather them simply recall them.

[I]t was clear that those who had stayed awake for more than 17 straight hours were in worse shape than those with a blood alcohol content of 0.5 percent


The amount of time each subject slept determined how well he or she performed on the task. Subjects who were able to reach deeper stages of sleep demonstrated a better command of flexible thinking, a vital cognitive skill that allows us to apply old facts and information to new situations. It was as if sleep stretched the muscles of the brain, and it responded by bending its conception of reality in a way that let it arrive at a new vision. Other subjects in studies who were allowed to sleep have finished mazes faster, have become less emotional when confronted with disturbing images, and have remembered a longer list of words than their peers who hadn’t been allowed to doze off.

This has real-world applications outside of the research labs, of course. Athletes, for whom any slight change in ability can mean the difference between winning and losing, are turning to sleep as one of the last untapped advantages left in sports. Some Major League Baseball coaches, for instance, have instituted rules that players must get to the ballpark early to take naps before games, all in hopes that the edge from extra sleep will result in a team that plays consistently well. Airline pilots, military soldiers, long-haul truckers and others who work dangerous jobs, meanwhile, are also more likely to receive orders to boost their sleep before coming on duty.

It’s a requirement that seems particularly effective with pitchers, for whom sheer athleticism is only half of the battle. The other half is knowing the tendencies of your opponent—whether he will bite at a high curveball, or how often he swings at the first pitch. A pitcher who isn’t getting enough sleep has already lost the memory battle that he fights every time he is on the mound.

That’s exactly the kind of mental contest in which Governor Perry essentially forfeited that fateful night in November, as he continued to campaign at a pace that gave him little time for sleep. Not long after the debate, Sen. John McCain told CNN’s Wolf Blitzer that he had some advice for Governor Perry: get some sleep. “Every time I’ve made a serious political mistake … it’s been when I’m tired,” he said.

That, in fact, could be our new rallying cry: more zzzs, fewer oops.

David K. Randall is a senior reporter at Reuters. He has previously written for The New York Times, New York magazine, Forbes, and the Associated Press, covering topics ranging from financial fraud to a unicycle club that meets at Grant’s Tomb.

Source: Sleep Your Way to the Top: How Sleep Equals Success – The Daily Beast

The brain: A roadmap to the mind

Decades of study and up-to-date brain imaging techniques have shed light on the workings of your body’s most mysterious organ. The brain’s complex interactions cannot be charted as precisely as, say, the interstate highway system – but clicking on the buttons below should give you a better idea of the lay of the land inside your head. Here…