Tuesday 24 May 2016

U.S. lawmaker orders NASA to plan for trip to Alpha Centauri

U.S. lawmaker orders NASA to plan for trip to Alpha Centauri by 100th anniversary of moon landing

It seems that the recently announced Breakthrough Starshot project—to send a privately funded fleet of tiny spacecraft to a nearby star—may have started a star rush. Today a senior U.S. lawmaker who helps write NASA’s budget called on the agency to begin developing its own interstellar probes, with the aim of launching a mission to Alpha Centauri, our nearest star system, in 2069—the centenary of the Apollo 11 moon landing.

Representative John Culberson (R–TX), a self-professed space fan who chairs the House of Representatives appropriations subpanel that oversees NASA, included the call for the ambitious voyage in a committee report released today. The report accompanies a bill setting NASA’s budget for the 2017 fiscal year, which begins 1 October; the full House appropriations panel is set to consider the bill on Tuesday.

In the report, Culberson’s panel “encourages NASA to study and develop propulsion concepts that could enable an interstellar scientific probe with the capability of achieving a cruise velocity of 0.1c [10% of the speed of light].” The report language doesn’t mandate any additional funding, but calls on NASA to draw up a technology assessment report and conceptual road map within 1 year.

A long, strange trip

Many scientists consider the idea of interstellar travel to be still firmly in the domain of science fiction. That’s principally because of the vast distances involved. Alpha Centauri is 4.4 light-years away, or nearly 40 trillion kilometers. The fastest spacecraft so far launched into space, the NASA-Germany Helios probes, traveled at 250,000 kilometers per hour. At that speed, it would take the probes 18,000 years to reach the nearest star to the sun. To get there in anywhere close to a human lifetime, spacecraft will need to travel a substantial fraction of light-speed—10% would get a craft to Alpha Centauri in 44 years.

Achieving such phenomenal speeds would require equally eye-watering amounts of energy, even for a relatively lightweight probe. It is this challenge that led the Starshot project, bankrolled by the Russian internet billionaire Yuri Milner, to propose developing a spacecraft-on-a-chip weighing less than 1 gram. And to avoid having to accelerate hefty engines and fuel, the craft will have large, featherweight light-sails and will be boosted to more than 20% of light-speed by an enormous array of high-powered lasers on Earth.

The House report acknowledges that conventional forms of propulsion, including chemical, solar-electric, and nuclear-thermal technologies, will never be able to achieve such interstellar speeds. It suggests a number of avenues that NASA might want to pursue, including propulsion based on nuclear fusion. This technology has yet to be mastered on Earth for conventional electricity supply, so developing a propulsion system for use in space is still a long way off. One variant mentioned in the report is antimatter-catalyzed fusion, which drives a spacecraft with a series of thermonuclear explosions. On Earth, such H-bombs are triggered by a conventional atomic bomb fueled with uranium or plutonium; in the antimatter triggered version, a small ball of antimatter meets normal matter and their annihilation provides the explosion, which sparks the much larger thermonuclear blast. How to protect a spacecraft and its crew from such forces, however, remains an unanswered question.

Another futuristic technology the House report mentions is the Bussard ramjet, which uses electromagnetic fields to scoop up hydrogen from the interstellar medium as it travels along, compressing it sufficiently for nuclear fusion to occur, providing thrust to drive the craft forward. Bussard ramjets are popular with science fiction authors because they effectively never run out of fuel, harvesting it as they move.

Starshot’s NASA roots

Although such approaches may seem impossibly sci-fi for many space scientists, the report also refers to “beam energy approaches.” The report mentions that the NASA Innovative Advanced Concepts (NIAC) program is already funding a study of “directed energy propulsion for wafer-sized spacecraft that in principle could achieve velocities exceeding 0.1c.” It’s no accident that this sounds familiar. The study in question, Directed Energy Propulsion for Interstellar Exploration (DEEP IN), was also the inspiration for Yuri Milner’s Starshot.

DEEP IN is the brainchild of Philip Lubin of the University of California, Santa Barbara. He says he had been developing various space applications for high-powered lasers and made several proposals to NIAC in 2014. The program jumped on the interstellar propulsion idea. “They just loved it,” Lubin says. NIAC began funding DEEP IN with $100,000 in early 2015 and recently awarded Lubin another $500,000 for further studies.

In the meantime, Lubin bumped into Pete Worden, former director of the NASA Ames Research Center in Moffett Federal Airfield in California, who had left to work with Milner on his Breakthrough Initiatives. Worden was enthused with Lubin’s idea of tiny, laser-driven interstellar spacecraft, and in January this year Lubin met with Milner, Worden, other Starshot staff, and Avi Loeb, a Harvard University astrophysicist who was advising Milner.

Last year, Loeb had studied a large number of proposals for interstellar travel on behalf of Milner. With the help of his Harvard students they had scoured the literature and studied other ideas that were brought to them. “None looked feasible, all except one,” says Loeb, and that was tiny spacecraft propelled by beams. According to Lubin, a Starshot meeting in March involving more than 20 people scrutinized the proposal in great detail looking for any flaws. Lubin’s original idea had been for the lasers to be stationed in space, but Milner insisted they had to be ground-based because otherwise the project would take too long and would be too expensive. Lubin says the meeting concluded that approach was hard, but not impossible and soon afterward the Starshot announcement was set for 12 April.

Loeb, for one, is excited to be starting on the project and says he already has two papers in the works. “This is more challenging than putting a man on the moon,” he says, because it involves a greater extrapolation from current technology. “It should be an exciting few years,” he says. “Our reputations now depend on this project.”

NIAC would be the natural home for any interstellar projects at NASA. NIAC Program Executive Jason Derleth in Washington, D.C., says it funds research that is “as close to the edge of science fiction without going over.” He welcomed the new interest from Congress. “To have anyone interested in what we’re doing is a good thing for the agency.”

But will it be NASA or Yuri Milner leading this Starshot? Loeb says he can see the two working together on it. “We need to keep our eye on the ball rather than who is holding it,” he says.

Can ADHD Appear for the First Time in Adulthood?.

- Attention deficit hyperactivity disorder (ADHD), usually diagnosed in children, may show up for the first time in adulthood, two recent studies suggest.

And not only can ADHD appear for the first time after childhood, but the symptoms for adult-onset ADHD may be different from symptoms experienced by kids, the researchers found.

“Although the nature of symptoms differs somewhat between children and adults, all age groups show impairments in multiple domains – school, family and friendships for kids and school, occupation, marriage and driving for adults,” said Stephen Faraone, a psychiatry researcher at SUNY Upstate Medical University in Syracuse, New York and author of an editorial accompanying the two studies in JAMA Psychiatry.

Faraone cautions, however, that some newly diagnosed adults might have had undetected ADHD as children. Support from parents and teachers or high intelligence, for example, might prevent ADHD symptoms from emerging earlier in life.

It’s not clear whether study participants “were completely free of psychopathology prior to adulthood,” Faraone said in an email.

One of the studies, from Brazil, tracked more than 5,200 people born in 1993 until they were 18 or 19 years old.

At age 11, 393 kids, or 8.9 percent, had childhood ADHD. By the end of the study, 492 participants, or 12.2 percent, met all the criteria for young adult ADHD except the age of diagnosis.

Childhood ADHD was more prevalent among males, while adult ADHD was more prevalent among females, the study also found.

Just 60 of the nearly 400 kids with ADHD still had symptoms at the end of the study, and only 60 of the nearly 500 adults with ADHD had been diagnosed as children.

“The main take-home message is that adult patients experiencing significant and lasting symptoms of inattention, hyperactivity or impulsivity that cause impairment should seek evaluation, even if they began recently by their perception or if family members deny their existence in childhood,” senior study author Dr. Luis Augusto Rohde, a psychiatry researcher at Federal University of Rio Grande Do Sul in Brazil said by email.

The second study focused on 2,040 twins born in England and Wales in 1994 and 1995. During childhood, 247 of them met the diagnosis criteria for ADHD. Of those, 54 still met the diagnosis criteria for the disease at age 18.

Among 166 individuals with adult ADHD, roughly one third didn’t meet the criteria for ADHD at any of four evaluations during childhood, the study also found.

It’s possible some of these adults had undiagnosed ADHD as kids, but symptoms may also look different in older people than they do in children, said senior study author Louise Arseneault of King’s College in London.

People with adult ADHD may have more inattentive symptoms like being forgetful or having difficulty concentrating, whereas children with ADHD may have more hyperactive symptoms, Arseneault said by email. “And if adults do experience hyperactive symptoms, these symptoms may manifest more as feelings of internal restlessness rather than obvious hyperactive behavior like running or climbing around in inappropriate situations,” she said.

7 “toxins” in food that are actually consuming.

Here is a list of 7 “toxins” in food that are actually consuming.

1. Refined Vegetable and Seed Oils

Refined vegetable- and seed oils include corn, sunflower, safflower, soybean and cottonseed oils.

Years ago, people were urged to replace saturated fats with vegetable oils to reduce their cholesterol levels and help prevent heart disease.

However, a lot of evidence suggests that these oils actually cause harm when consumed in excess.

Vegetable oils are highly refined products with no essential nutrients. In that respect, they are “empty” calories.

They’re high in polyunsaturated omega-6 fats, which contain multiple double bonds that are prone to damage and rancidity when exposed to light or air.

These oils are particularly high in omega-6linoleic acid. While you do need some linoleic acid, most people today are eating much more than they need.

On the other hand, most people don’t consume enough omega-3 polyunsaturated fatty acids to maintain a proper balance between these fats.

In fact, it’s estimated that the average person eats up to 16 times as many omega-6 fats as omega-3 fats, although the ideal ratio may be between 1:1 and 3:1.

High intakes of linoleic acid may increase inflammation, which can damage the endothelial cells lining your arteries and increase your risk of heart disease.

In addition, animal studies suggest it may promote the spread of cancer from breast cells to other tissues, including the lungs.

Observational studies found that women with the highest intakes of omega-6 fats and lowest intakes of omega-3 fats had an 87–92% greater risk of breast cancer than those with more balanced intakes.

What’s more, cooking with vegetable oils is even worse than using them at room temperature. When they’re heated, they release harmful compounds that may further increase the risk of heart disease, cancer and inflammatory diseases

Although the evidence on vegetable oil is mixed, many controlled trials suggest that they are harmful.

Bottom Line: Processed vegetable and seed oils contain omega-6 fats. Most people are eating too much of these fats already, which may lead to several health problems.

2. BPA

Bisphenol-A (BPA) is a chemical found in the plastic containers of many common foods and beverages.

The main food sources are bottled water, packaged foods and canned items, such as fish, chicken,beans and vegetables.

Studies have shown that BPA can leech out of these containers and into the food or beverage.

Researchers have reported that food sources make the biggest contribution to BPA levels in the body, which can be determined by measuring BPA in urine.

One study found BPA in 63 of 105 samples of food, including fresh turkey and canned infant formula.

BPA is believed to mimic estrogen by binding to the receptor sites meant for the hormone. This can disrupt normal function.

The recommended daily limit of BPA is 23 mcg/lb (50 mcg/kg) of body weight. However, 40 independent studies have reported that negative effects have occurred at levels below this limit in animals.

What’s more, while all 11 industry-funded studies found that BPA had no effects, more than 100 independent studies have found it to be harmful.

Studies on pregnant animals have shown that BPA exposure leads to problems with reproduction and increases the future breast and prostate cancer risk in a developing fetus.

Some observational studies have also found that high BPA levels are associated with infertility, insulin resistance, type 2 diabetes and obesity.

Results from one study suggest a connection between high BPA levels and polycystic ovarian syndrome (PCOS). PCOS is a disorder of insulin resistance characterized by elevated levels of androgens, such as testosterone.

Research has also linked high BPA levels to altered thyroid hormone production and function. This is attributed to the chemical binding to thyroid hormone receptors, which is similar to its interaction with estrogen receptors.

You can reduce your BPA exposure by looking for BPA-free bottles and containers, as well as by eating mostly whole, unprocessed foods.

In one study, families who replaced packaged foods with fresh foods for 3 days experienced a 66% reduction in BPA levels in their urine, on average.

You can read more about BPA here: What is BPA and Why is it Bad for You?

Bottom Line: BPA is a chemical commonly found in plastic and canned items. It may increase the risk of infertility, insulin resistance and disease.

3. Trans Fats

Trans fats are the unhealthiest fats you can eat.

They’re created by pumping hydrogen into unsaturated oils in order to turn them into solid fats.

Your body doesn’t recognize or process trans fats in the same way as naturally occurring fats.

Not surprisingly, eating them can lead to a number of serious health problems.

Animal and observational studies have repeatedly shown that trans fat consumptioncauses inflammation and negative effects on heart health .

Researchers who looked at data from 730 women found that inflammatory markers were highest in those who ate the most trans fats, including 73% higher levels of CRP, which is a strong risk factor for heart disease.

Controlled studies in humans have confirmed that trans fats lead to inflammation, which has profoundly negative effects on heart health. This includes impaired ability of arteries to properly dilate and keep blood circulating.

In one study looking at the effects of several different fats in healthy men, only trans fats increased a marker known as e-selectin, which is activated by other inflammatory markers and causes damage to the cells lining your blood vessels.

In addition to heart disease, chronic inflammation is at the root of many other serious conditions, such as insulin resistance, type 2 diabetes and obesity.

The available evidence supports avoiding trans fats as much as possible and using healthier fats instead.

Bottom Line: Many studies have found that trans fats are highly inflammatory and increase the risk of heart disease and other conditions.

4. Polycyclic Aromatic Hydrocarbons (PAHs)

Woman Taking Burned Chicken Out of the Oven

Red meat is a great source of protein, iron and several other important nutrients.

However, it can release toxic byproducts called polycyclic aromatic hydrocarbons(PAHs) during certain cooking methods.

When meat is grilled or smoked at high temperatures, fat drips onto hot cooking surfaces, which produces volatile PAHs that can seep into the meat. Incomplete burning of charcoal can also cause PAHs to form.

Researchers have found that PAHs are toxic and capable of causing cancer.

PAHs have been linked to an increased risk of breast and prostate cancer in many observational studies, although genes also play a role.

Additionally, researchers have reported that high intakes of PAHs from grilled meats may increase the risk of kidney cancer. Again, this appears to be partly dependent on genetics, as well as additional risk factors, such as smoking.

The strongest association appears to be between grilled meats and cancers of the digestive tract, especially colon cancer.

It’s important to note that this connection with colon cancer has only been seen in red meats, such as beef, pork, lamb and veal. Poultry, such as chicken, appear to have either a neutral or protective effect on colon cancer risk.

One study found that when calcium was added to diets high in cured meat, markers of cancer-causing compounds decreased in both animal and human feces.

Although it’s best to use other methods of cooking, you can reduce PAHs by as much as 41–89% when grilling by minimizing smoke and quickly removing drippings.

Bottom Line: Grilling or smoking red meat produces PAHs, which have been linked to an increased risk of several cancers, especially colon cancer.

5. Coumarin in Cassia Cinnamon

Cinnamon can provide several health benefits, including lower blood sugar and reduced cholesterol levels in people with type 2 diabetes.

However, cinnamon also contains a compound called coumarin, which is toxic when consumed in excess.

Two of the most common types of cinnamon are cassia and Ceylon.

Ceylon cinnamon comes from the inner bark of a tree in Sri Lanka known as Cinnamomum zeylanicum. It is sometimes referred to as “true cinnamon.”

Cassia cinnamon comes from the bark of a tree known as Cinnamomum cassia that grows in China. It is less expensive than Ceylon cinnamon and accounts for about 90% of the cinnamon imported into the US and Europe.

Cassia cinnamon contains much higher levels of coumarin, which is linked to an increased risk of cancer and liver damage at high doses.

The safety limit for coumarin in food is 0.9 mg/lb (2 mg/kg).

However, one investigation found cinnamon baked goods and cereals that contained an average of 4 mg/lb (9 mg/kg) of food, and one type of cinnamon cookies that contained a whopping 40 mg/lb (88 mg/kg).

What’s more, it’s impossible to know how much coumarin is actually in a given amount of cinnamon without testing it.

German researchers who analyzed 47 different cassia cinnamon powders found that coumarin content varied dramatically among the samples.

The tolerable daily intake (TDI) of coumarin has been set at 0.45 mg/lb (1 mg/kg) of body weight and was based on animal studies of liver toxicity.

However, studies on coumarin in humans have found that certain people may be vulnerable to liver damage at even lower dosages.

While Ceylon cinnamon contains far less coumarin than cassia cinnamon and can be consumed liberally, it’s not as widely available. Most of the cinnamon in supermarkets is the high-coumarin cassia variety.

That being said, most people can safely consume up to 2 grams (0.5-1 teaspoon) of cassia cinnamon per day. In fact, several studies have used three times this amount with no reported negative effects.

Bottom Line: Cassia cinnamon contains coumarin, which may increase the risk of liver damage or cancer if consumed in excess.

6. Added Sugar

Sugar and high-fructose corn syrup are often referred to as “empty calories.”

However, the harmful effects of sugar go way beyond that.

Sugar is high in fructose, and excess fructose intake has been linked to many serious conditions, including obesity, type 2 diabetes, metabolic syndrome and fatty liver disease.

Excess sugar is also linked to breast and colon cancer. This may be due to its effect on blood sugar and insulin levels, which can drive tumor growth.

One observational study of more than 35,000 women found that those with the highest sugar intakes had double the risk of developing colon cancer as those who consumed diets lower in sugar.

While small amounts of sugar are harmless for most people, some individuals are unable to stop after a small amount. In fact, they may be driven to consume sugar in the same way that addicts are compelled to drink alcohol or take drugs.

Bottom Line: A high intake of added sugars may increase the risk of several diseases, including obesity, heart disease, type 2 diabetes and cancer.

7. Mercury in Fish

Most types of fish are extremely healthy.

However, certain varieties contain high levels of mercury, a known toxin.

Seafood consumption is the largest contributor to mercury accumulation in humans.

This is a result of the chemical working its way up the food chain in the sea.

Plants that grow in mercury-contaminated waters are consumed by small fish, which are then consumed by larger fish. Over time, mercury accumulates in the bodies of those larger fish, which are eventually eaten by humans.

In the US and Europe, determining how much mercury people get from fish is difficult. This is due to the wide-ranging mercury content of different fish.

Mercury is a neurotoxin, meaning it can damage the brain and nerves. Pregnant women are at particularly high risk, since mercury can affect the fetus’s developing brain and nervous system.

A 2014 analysis found that in several countries, mercury levels in the hair and blood of women and children were significantly higher than the World Health Organization recommends, particularly in coastal communities and near mines.

Another study found that the amount of mercury varied widely among different brands and types of canned tuna. It found that 55% of the samples were in excess of the EPA’s 0.5 ppm (parts per million) safety limit.

Some fish, such as king mackerel and swordfish, are extremely high in mercury and should be avoided. However, eating other types of fish is still advised because they have many health benefits.

To limit your mercury exposure, choose seafood from the “lowest mercury” category on this list. Fortunately, the low-mercury category includes most of the fish highest in omega-3 fats, such as salmon, herring, sardines and anchovies.

The benefits of eating these omega-3 rich fish far outweigh the negative effects of small amounts of mercury.

Bottom Line: Certain fish contain high levels of mercury. However, the health benefits of eating low-mercury fish far outweigh the risks.

My world

Tuesday 24 May 2016