FDA to ease ban on blood donations by gay men

Federal officials have moved closer to overturning a decades-old ban on blood donations from gay and bisexual men, but activists say the proposed alternative would continue to stigmatize men who have sex with men.

FILE - In this July 19, 2010 file photo, blood is collected during a blood drive at Saint Vincent Health Center in Erie, Pa. The Food and Drug Administration on Tuesday, Dec. 23, 2014 recommended an end to the nation’s lifetime ban on blood donations from gay and bisexual men, a 31-year-old policy that many medical groups and gay activists say is no longer justified. (AP Photo/Erie Times-News, Jack Hanrahan, File) MANDATORY CREDIT; MAGS OUT

The Food and Drug Administration said on Tuesday it will recommend lifting the lifetime ban early next year, replacing it with a policy barring donations from men who have had sex with another man in the previous 12 months. The change would overturn a 31-year-old policy that many medical groups and gay activists say is no longer justified, given advances in HIV testing.

But activists questioned whether requiring a year of celibacy from gay men amounted to a significant policy shift.

“Some may believe this is a step forward, but in reality, requiring celibacy for a year is a de facto lifetime ban,” Gay Men’s Health Crisis, a New York-based non-profit that supports AIDS prevention and care, said after the announcement.

The blanket ban dates from the early years of the AIDS crisis and was intended to protect the blood supply from what was a then little-understood disease. But many medical groups, including the American Medical Association, say the policy is no longer supported by science. Australia, Japan, the U.K. and many other countries previously moved to a one-year period.

The agency will recommend the switch in draft guidelines early next year and move to finalize them after taking comments from the public, FDA officials told reporters. FDA Deputy Director Dr. Peter Marks declined to give a timeframe for completing the process but said, “We commit to working as quickly as possible on this issue.”

He said some of the most compelling evidence for changing the policy comes from Australia, which put in place a one-year ban on donations over a decade ago. Recently published studies showed no change in the safety of the blood supply after making the switch.

Additionally, studies conducted by the U.S. government suggest gay and bisexual men are actually more likely to abide by donation guidelines under a 12-month prohibition period. All blood donors take a questionnaire about their health and sexual behaviour, but some gay men reportedly answer inaccurately to donate blood.

All U.S. blood donations are screened for HIV but the testing only detects the virus after it’s been in the bloodstream about 10 days. Still, FDA officials said current research does not support reducing the donation ban below the one-year mark, though the agency may consider changing the timeframe.

“We’re committed to re-evaluating the blood donor deferral policy in the future as new scientific evidence becomes available, but at this time we simply don’t have the evidence,” the FDA Deputy Director said in a teleconference with reporters.

According to government figures, men who have had sex with other men represent about 2 per cent of the U.S. population, yet account for at least 62 per cent of all new HIV infections in the U.S.

The American Red Cross estimates the risk of getting an HIV-positive blood donation is one in 1.5 million. About 15.7 million blood donations are collected in the U.S. each year.

Despite the shift in approach from the federal government, gay advocates said on Tuesday that requiring a year of abstinence from gay and bisexual men was unrealistic and not supported by science.

“This new policy cannot be justified in light of current scientific research and updated blood screening technology,” said David Stacy of Human Rights Campaign, the largest U.S. gay rights group.

The U.S. blood banking system already bars donations from people who have had sex with a prostitute or an intravenous drug user in the past 12 months.

The FDA implemented the lifetime ban on donations from men who have sex with men in 1983, when health officials were first recognizing the risk of contracting AIDS via blood transfusions. Under the policy, blood donations are barred from any man who has had sex with another man at any time since 1977 the start of the AIDS epidemic in the U.S.

The push for a new policy gained momentum in 2006, when the Red Cross, the American Association of Blood Banks, and America’s Blood Centers called the ban “medically and scientifically unwarranted.” Last year the American Medical Association voted to oppose the policy.

Patient groups that rely on a safe blood supply, including the National Hemophilia Foundation, have also voiced support for dropping the ban.

The switch in policy could increase the U.S. blood supply by 2 to 4 per cent by making 2 million additional men eligible to donate, according to researchers at UCLA’s Williams Institute.

CDC is covering up 1,400 potential Ebola cases in US, acclaimed journalist reveals.

A noted investigative journalist says the American people are still not being kept up to speed about the dangers of possible spread of Ebola in the country, and that the government’s chief agency for handling such emergencies is the primary culprit.


In a recent interview with Fox NewsMedia Buzz program, former CBS journalist Sharyl Attkisson said that the Centers for Disease Control and Prevention, as well as the Obama Administration, is not telling the public about all of the possible cases of Ebola that officials are continuing to monitor. She went on to say there was an effort to control the Ebola message.

“A lot of the media coverage has gone from overtime to almost nothing since they appointed the ‘Ebola czar,'” Attkisson said.

CDC Director Dr. Tom Frieden initially was all over the place conducting interviews and talking about the deadly disease after the first case was diagnosed in September, and afterward when two nurses caring for the first victim were also diagnosed with the virus.

Then, in late October, President Obama appointed longtime Democratic political operative Ron Klain to be an “Ebola czar,” but he was nearly silent (and has now announced that he is resigning his post) about the disease. Media coverage in the U.S. of the virus has also all but dried up.

Don’t hype it, just report it

Attkisson said on the program that infectious disease experts are still “very concerned,” because if the deadly virus gets out of control in the United States, “we will not even be able to, obviously, deal with it.”

The public is somewhat safer now, she told host Howard Kurtz, but the reason for that is because there was media coverage and a public outcry that changed completely how the government handled the Ebola crisis. Attkisson also said that she phoned the CDC recently to inquire about how many potential cases were being actively monitored in the U.S., and was told that 1,400 people were being followed.

“I said, ‘Where is that on your on your website, these updates?’ They said, ‘We’re not putting it on the web.’ So, I think there is an effort to control the message and to tamp it down,” she told Kurtz. “This is public information we have a right to know and the media should not hype it, but cover it.”

Meanwhile, the BBC reported in late December that spending cuts by the International Monetary Fund (IMF) were being blamed by some researchers in the United Kingdom as having contributed to the rapid spread of the virus in the most-affected West African nations.

The cuts led to “under-funded, insufficiently staffed, and poorly prepared health systems” in Sierra Leone, Guinea and Liberia, the researchers said, as quoted by the BBC.

IMF officials denied the allegation, the British network reported.

Budget cuts led to inadequate hiring, lack of proper pay

So far, the virus has killed more than 7,300 people, most of them in the three West African nations.

“A major reason why the Ebola outbreak spread so rapidly was the weakness of healthcare systems in the region, and it would be unfortunate if underlying causes were overlooked,” Cambridge University sociologist and lead author of a study examining IMF’s role in the crisis Alexander Kentikelenis said.

The study went on to say that policies requiring government spending be cut were “extremely strict, absorbing funds that could be directed to meeting pressing health challenges.”

In an interview with the BBC’s Newsday program, Kentikelenis said that caps on labor and wage measures meant that countries were unable to hire adequate health staff and then pay them properly.

He also said the IMF’s emphasis on a decentralized healthcare delivery system made it much more difficult to mobilize a coordinated response to health emergencies like the Ebola outbreak.






Learn more: http://www.naturalnews.com/048090_ebola_infections_cdc_coverup_infectious_disease.html#ixzz3Muw0IY5p

Scripps Research Institute Scientists Uncover New, Fundamental Mechanism for How Resveratrol Provides Health Benefits

Scientists at The Scripps Research Institute (TSRI) have found that resveratrol, the red-wine ingredient once touted as an elixir of youth, powerfully activates an evolutionarily ancient stress response in human cells. The finding should dispel much of the mystery and controversy about how resveratrol really works.

“This stress response represents a layer of biology that has been largely overlooked, and resveratrol turns out to activate it at much lower concentrations than those used in prior studies,” said senior investigator Paul Schimmel, professor and member of the Skaggs Institute for Chemical Biology at TSRI.

“With these findings we have a new, fundamental mechanism for the known beneficial effects of resveratrol,” said lead author Mathew Sajish, a senior research associate in the Schimmel laboratory.

The discovery is reported in the advance online edition of Nature on December 22.

Resveratrol is a compound produced in grapes, cacao beans, Japanese knotweed and some other plants in response to stresses including infection, drought and ultraviolet radiation. It has attracted widespread scientific and popular interest over the past decade, as researchers have reported that it extended lifespan and prevented diabetes in obese mice and vastly increased the stamina of ordinary mice running on wheels.

More recently, though, scientists in this field have disagreed about the signaling pathways resveratrol activates to promote health, calling into question some of resveratrol’s supposed health benefits—particularly given the unrealistically high doses used in some experiments.

Outsiders to the Controversy

Schimmel and Sajish came to this controversy as outsiders. Schimmel’s laboratory is known for its work not on resveratrol but on an ancient family of enzymes, the tRNA synthetases. The primary and essential function of these enzymes is to help translate genetic material into the amino-acid building blocks that make proteins. But as Schimmel and others have shown since the late 1990s, tRNA synthetases have acquired an extensive set of added functions in mammals.

Earlier Xiang-Lei Yang, a TSRI professor in the Departments of Chemical Physiology and Cell and Molecular Biology and former member of Schimmel’s laboratory, began to find hints that a tRNA synthetase called TyrRS, which links the amino acid tyrosine to the genetic material that codes for it, can move to the cell nucleus under stressful conditions—apparently taking on a protective, stress-response role. Sajish noted that resveratrol appeared to have broadly similar stress-response properties and also resembled TyrRS’s normal binding partner tyrosine. “I began to see TyrRS as a potential target of resveratrol,” he said.

For the new study, Sajish and Schimmel put TyrRS and resveratrol together and showed with tests including X-ray crystallography that resveratrol does indeed mimic tyrosine, well enough to fit tightly into TyrRS’s tyrosine binding pocket. That binding to resveratrol, the team found, takes TyrRS away from its protein translation role and steers it to a function in the cell nucleus.

Tracking the resveratrol-bound TyrRS in the nucleus, the researchers determined that it grabs and activates the protein, PARP-1, a major stress response and DNA-repair factor thought to have a significance influence on lifespan. The scientists confirmed the interaction in mice injected with resveratrol. TyrRS’s activation of PARP-1 led, in turn, to the activation of a host of protective genes including the tumor-suppressor gene p53 and the longevity genes FOXO3A and SIRT6.

Compatible with Red Wine

The first studies of resveratrol in the early 2000s had suggested that it exerts some of its positive effects on health by activating SIRT1, also thought to be a longevity gene. But SIRT1’s role in mediating resveratrol’s reported health-boosting effects has been questioned lately in terms of its particular role.

The team’s experiments showed, however, that the TyrRS-PARP-1 pathway can be measurably activated by much lower doses of resveratrol—as much as 1,000 times lower—than were used in some of the more celebrated prior studies, including those focused on SIRT1. “Based on these results, it is conceivable that moderate consumption of a couple glasses of red wine (rich in resveratrol) would give a person enough resveratrol to evoke a protective effect via this pathway,” Sajish said. He also suspects that effects of resveratrol that only appear at unrealistically high doses may have confounded some prior findings.

Why would resveratrol, a protein produced in plants, be so potent and specific in activating a major stress response pathway in human cells? Probably because it does much the same in plant cells, and probably again via TyrRS—a protein so fundamental to life, due to its linkage to an amino acid, that it hasn’t changed much in the hundreds of millions of years since plants and animals went their separate evolutionary ways. “We believe that TyrRS has evolved to act as a top-level switch or activator of a fundamental cell-protecting mechanism that works in virtually all forms of life,” said Sajish.

Whatever activity resveratrol naturally has in mammals may be an example of hormesis: the mild, health-promoting activation of a natural stress response. “If resveratrol brought significant benefits to mammals, they might have evolved a symbiotic relationship with resveratrol-producing plants,” Sajish said.

“We think this is just the tip of the iceberg,” said Schimmel. “We think there are a lot more amino-acid mimics out there that can have beneficial effects like this in people. And we’re working on that now.”

Schimmel and his laboratory also are searching for molecules that can activate the TyrRS stress response pathway even more potently than resveratrol does.

The National Cancer Institute (CA92577), the National Foundation for Cancer Research and aTyr Pharma, Inc. provided funding for the study, “A human tRNA synthetase is a potent PARP1-activating effector target for resveratrol.” For more information, see http://www.nature.com

Opioid Linked to Low Blood Sugar

Tramadol was associated with an increased risk of hospitalization for hypoglycemia.

  • Medpage Today

The mild opioid tramadol was associated with an increased risk of hospitalization for hypoglycemia, researchers reported.

In a case-control study, the use of tramadol was associated with a 52% higher risk of hospitalization for hypoglycemia compared with codeine, Samy Suissa, PhD, of McGill University in Montreal, and colleagues reported online in JAMA Internal Medicine.

Risk was highest within the first 30 days of use, they reported — nearly three times as high as that seen with codeine.

Tramadol is seen as a lower-risk alternative to other opioids and its prescriptions have increased in recent years. In August, the opioid became a schedule IV controlled substance.

Suissa and colleagues wrote that three recent case reports have described tramadol-induced hypoglycemia, which included patients with and without diabetes who used the drug at recommended doses.

It’s biologically plausible that tramadol may induce hypoglycemia; it activates the mu-opioid receptor and inhibits central serotonin and norepinephrine reuptake. Serotonin pathways are known to have complex effects on peripheral glucose regulation, the researchers wrote, and antidepressants that work via either serotonin or norepinephrine reuptake inhibition both have been tied to hypoglycemia risk.

They conducted a nested case-control analysis within the U.K. Clinical Practice Research Datalink and the Hospital Episodes Statistics database of 334,034 patients newly treated with tramadol or codeine for pain between 1998 and 2012.

Among these, 1,105 were hospitalized for hypoglycemia during follow-up, and were subsequently matched with 11,019 controls.

Overall, tramadol use was associated with an increased risk of hospitalization for hypoglycemia compared with codeine use (odds ratio 1.52, 95% CI 1.09 to 2.10).

That risk was particularly elevated in the first 30 days of use, they reported (OR 2.61, 95% CI 1.61 to 4.23).

Suissa and colleagues noted that the 2-day increased risk of hospitalization was confirmed in an propensity score-adjusted model (HR 3.6, 95% CI 1.56 to 8.34) and in cross-over analyses (OR 3.80, 95% CI 2.64 to 5.47).

In an accompanying commentary, Lewis Nelson, MD, of New York University Medical Center in New York City, and David Juurlink, MD, PhD, of Sunnybrook Health Sciences Center in Toronto, noted that hypoglycemia was uncommon in the study, with only eight events in more than 26,000 person-months of tramadol therapy.

It’s also unclear why hypoglycemia is less common in patients taking other mu-opioid agonists such as morphine, oxycodone, and hydrocodone, they noted.

Still, since hypoglycemia “can be life threatening, clinicians should remain vigilant for this potential complication of tramadol use, in patients taking the drug as directed, as well as those who abuse it,” they wrote. “Whether tramadol therapy should be particularly avoided in patients receiving hypoglycemic drugs is unclear, but given the drug’s limited benefit and unpredictable pharmacological properties, it should be handled at least as carefully in these patients as in others.”

Lose Weight Effectively With Weight Training; More Effective Than Running, Cycling, Or Stair Climbing

Experts are saying weight training is underrated when it comes to choosing effective weight loss workouts because prior studies too often tout the benefits of aerobic exercises. A study conducted by researchers at Harvard School of Public Health (HSPH) compared two different exercises to figure out which ones provided more weight loss benefits, and published their findings in the journal Obesity.

Weight Training Is The Key To Weight Loss

“Because aging is associated with sarcopenia, the loss of skeletal muscle mass, relying on body weight alone is insufficient for the study of healthy aging,” the study’s lead author Rania Mekary, a researcher in HSPH’s Department of Nutrition, said in a press release. “Measuring waist circumference is a better indicator of healthy body composition among older adults. Engaging in resistance training or, ideally, combining it with aerobic exercise could help older adults lessen abdominal fat while increasing or preserving muscle mass.”

Over a 12-year period, researchers measured the waist circumference and body weight of 10,500 healthy American men who were 40 and older. The study took place between 1996 and 2008, where they compared 20 minutes of weight training a day to moderate-to-vigorous aerobic exercise, yard work, or stair climbing. When it comes to losing inches from their waistline, weight training was the most effective. For years, aerobic exercises, such as cycling, swimming, stair climbing, elliptical, dancing, and running have been some of the most relied upon exercise approaches for weight loss, yet weight training trumps them all.

Muscle tissue growth is stimulated when pressure is applied to it, which is why using weights with repetitions improves muscle response. Many times, dieters will lighten up or avoid weight lifting all together, especially females, because they think they’ll bulk instead of slim down. Fewer repetitions with heavier weight workouts actually burn more calories during the workout because it requires greater exertion from the body. Women shouldn’t shy away from weight training because they don’t naturally have enough testosterone to achieve the physique of a body builder.

1. Farmer’s Walk

Heavy dumbbells or short bars can be used to workout forearms, abdominals, glutes, hamstrings, lower back, quadriceps, and traps. Start by standing between the weights and grip the handles. Lift by driving your heels into the floor, while keeping your back straight and head staring forward. Walk 50 to 100 feet as fast as possible with short steps and even breathing.

2. Kettlebell Stand-Up

Kettlebells engage the shoulders, abdominals, calves, hamstrings, quadriceps, and triceps in a standup workout, also known as the “Turkish get-up.” Lie on your back and hold the kettlebell straight up with one hand. Bend the knee on the same side as the kettlebell. Push up into a seated position using your free hand. Slowly stand up and reverse the motion.

3. Barbell Deadlift

Using a barbell, this workout will work your lower back, calves, forearms, flutes, hamstrings, lats, quadriceps, and traps. Stand in front of a barbell and keep your back as straight as possible. Bend knees, tilt torso forward, and overhand grip the bar with hands shoulder-length apart. As you breathe out, lean forward and lift the bar with your body into an upright position. Push out your chest and keep your back straight until you’re ready to bend your knees and drop back down slowly until the bar touches the floor.

“This study underscores the importance of weight training in reducing abdominal obesity, especially among the elderly,” the study’s senior author Frank Hu, professor of nutrition and epidemiology at HSPH, said in a press release. “To maintain a healthy weight and waistline, it is critical to incorporate weight training with aerobic exercise.”

Source: Mekary R, Hu F, Giovannucci E, Rimm E, Willet W, and Asgarzadeh M, et al. Weight training, aerobic physical activities, and long-term waist circumference change in men.Obesity. 2014.

No cure for brokenhearted: Research finds time doesn’t heal heartbreak

A disturbing condition, known as the ‘broken heart syndrome,’ doesn’t necessarily heal with time, researchers at the University of Aberdeen have found. There is no treatment for the disorder, which was previously thought to recover in due course.

Reuters / Radu Sigheti

A team of researchers at Scotland’s Aberdeen University has spent four years studying the syndrome, commonly referred to as a “broken heart,” and medically known as Takotsubo stress cardiomyopathy (TSM). The result of their work turned out to be heartbreaking indeed: “There is no known treatment for the condition.”

The syndrome, which was first described in Japan in 1990, is usually sparked by stress, following life events such as losses of family members or friends, involvement in an accident or rueful feelings caused by relationship break-ups – mostly affecting women.

Patients suffering from TSM might experience severe chest pains associated with a heart attack, medics say, but when their coronary arteries are checked, no blockage is found. But “patients can go downhill very quickly,” scientists warn, as their heart muscle functions poorly.

“The usual test for heart function is an echocardiogram (Echo) test and when we conduct this it shows that the heart is back to normal… However, when talking to the patients they report that they are still not feeling themselves, cannot take part in strenuous activity and many have been unable to return to work,”said Dana Dawson, who led the Aberdeen research team.

Having studied brokenhearted patients as a group rather than individual cases, and using more sophisticated diagnostic tools, including Cardiac Magnetic Resonance and Spectroscopy, scientists found continued abnormalities in the hearts of suffering people.

“We also observed that the ability of the heart to generate the energy it needs to produce a pumping action was very much reduced,” Dawson said.

“Everyone knows someone who has had a heart attack, but I’ve never met anyone else who has been through this so it is nice to contribute to a study,” said Michael Strachan, who was diagnosed with TSM. He expressed the hope that his participation might help scientists arrive at a better understanding of the condition in the future.

Researchers say they need to get a better understanding of the complaint’s exact causes first, before further studies can be carried out into possible treatments.

Acoustic tweezers manipulate cell-to-cell contact

Sound waves can precisely position groups of cells for study without the danger of changing or damaging the cells, according to a team of Penn State researchers who are using surface acoustic waves to manipulate cell spacing and contact.

“Optical tweezers are the gold-standard technique in the field,” said Tony Jun Huang, professor of engineering science and mechanics. “They can trap two in place, but because of their high power they tends to affect the integrity of cells, and sometimes damage them.

Acoustic tweezers use the same low-power acoustic waves as those used in existing ultrasound machines, so they are gentle and can preserve cell integrity.

The researchers are manipulating cells so that they can look at direct contact between two cell membranes or precisely control and maintain a variety of distances between cells and determine how cells communicate.

“The value of acoustic tweezers for studying cell-to-cell information transfer is their ability to separate the cells to a precise distance or to bring them to a predetermined contact,” said Stephen J. Benkovic, Evan Pugh Professor and Eberly Chair in Chemistry. “Optical tweezers can do this to some extent but suffer from heating of the sample.”

The acoustic tweezers device that the researchers envision is no larger than a cell phone and can achieve a throughput of thousands of cells. By altering the acoustic field, the cells can be precisely manipulated without damage. Because the acoustic tweezers operate in a vertical channel that holds the cell-containing liquid, the researchers can trap the cells in suspension or allow them to settle onto the surface of the substrate.

Micrographs of cells separated at various intervals from 0 microns to 15 microns. Credit: Tony Jun Huang, Penn State

The researchers place four acoustic sources on opposite sides of the substrate. When opposing devices send out surface acoustic waves, they set up a grid of nodes where the sound pressure cancels out. Cells become trapped at those nodes. By modulating the power and frequencies of the acoustic sources, the researchers can manipulate the number of cells and also their position. Two cells can be moved to touch each other or to almost touch each other with a variety of separation distances.

The cells can also be positioned in patterns including lines of multiple cells, daisy-like clumps of cells or even triangles of cells.

“With present technologies, the generation of a desired cell-to-cell contact is often random or limited in number,” said Benkovic. “With standing , precise positioning of cells can be achieved on a multi-cellular level so that planned patterns of cellular arrays can be achieved.

Micrographs of cells arranged in straight lines, globs and trianges. Credit: Tony Jun Huang

“One can imagine a study of a cell’s infection by a bacterium as well as the creation of a long cellular assembly, for example the formation of a nerve from neurons.”

Because the can be created on a substrate that is transparent, the researchers can use microscopes to view the resulting cell alignments. Huang, Benkovic and colleagues put fluorescent dye into one of a pair of almost touching cells and watched the dye move into the neighboring cell through tiny protein channels established between them, demonstrating how chemical communication might be tracked using this device.

Real-time animated cyberattack map is fascinating and terrifying .

For the most part, cyberattacks are sort of an abstract thing that we hear about either during or after they have happened. You see that a service has gone down for a period of time or an apology email after the fact. Visualizing something like a cyberattack is difficult, which is often why in movies and television the efforts to make these events look more exciting often end up looking ridiculous. The folks at Norse Corporation have assembled a visual tool to help better demonstrate a tiny fraction of what cyberattacks look like, and it’s the kind of thing you’re going to want to leave open in a browser tab just to watch from time to time.

Since it’s impossible to watch as every cyberattack happens in the world, Norse has deployed and impressive network of honeypots to help monitor attackers that are effectively casting a wide net to see what gets caught. Contrary to popular belief, most cyberattacksaren’t the result of a specific target being called out and attacked. Instead, bots and scripts are set to probe anything with an IP address to see if access can be gained by force. On the Norse map, you can see the different attack types being used as these attempts happen, as well as what country the attack originated from and a visual history of attacks on a single honeypot if you mouse over any one target.

What makes this map so chilling is that these attacks are a random string of events representing a tiny fraction of all of the attack attempts happening all day, every day across the globe. It’s a constant reminder to ensure the services and devices you use are up to date and don’t fall victim to a random effort from one of these automated probes.

Now, a supertube that’s faster than bullet train

A new start—up known as Hyperloop Transportation Technologies is planning to develop a supertube that would take passengers from Los Angeles to San Francisco in 35 minutes flat at a speed of 760 miles per hour. The trip currently takes up to 12 hours by train and more than six hours by car.

Passengers get into the Shinkansen bullet train at Tokyo station.

Hyperloop, the tube transport dream of SpaceX founder and Tesla Motors CEO Elon Musk, could be ready for passengers in as few as 10 years, the Daily Mail reported.

Over 100 engineers from across the world are working on Musk’s supertube. Inside the tubes, hyperloop pods are mounted on thin skis made out of inconel, an alloy that can withstand high pressure and heat.

Air is pumped into the skis via small holes to make an air cushion with each pod having air inlets at the front.

An electric turbo compressor would compress air from the nose and route it to the skis and the capsule.

Magnets on the skis and an electromagnetic pulse would provide the pod its initial thrust.

The capsules carrying six to eight people would depart every 30 seconds.

“The only resistance would be the air in front of the capsule which we moved to the back by using a compressor,” Hyperloop CEO Dirk Ahlborn was quoted as saying.

According to Musk, Hyperloop would be a practical solution for travel between cities separated by 1,000 miles or less.

Researchers read and write brain activity with light

A team of neuroscientists at University College London has developed a new way of simultaneously recording and manipulating the activity of multiple cells in the brains of live animals using pulses of light.

The technique, described today in the journal Nature Methods, combines two existing state-of-the-art neurotechnologies. It may eventually allow researchers to do away with the cumbersome microelectrodes they traditionally used to probe neuronal activity, and to interrogate the brain’s workings at the cellular level in real time and with unprecedented detail.

One of them is optogenetics. This involves creating genetically engineered mice expressing algal proteins called Channelrhodopsins in specified groups of neurons. This renders the cells sensitive to light, allowing researchers to switch the cells on or off, depending on which Channelrhodopsin protein they express, and which wavelength of light is used. This can be done on a millisecond-by-millisecond timescale, using pulses of laser light delivered into the animals’ brains via an optical fibre.

The other is calcium imaging. Calcium signals are crucial for just about every aspect of neuronal function, and nerve cells exhibit a sudden increase in calcium ion concentration when they begin to fire off nervous impulses. Using dyes that gives off green fluorescence in response to increases in calcium concentration, combined with two-photon microscopy, researchers can detect this signature to see which cells are activated. In this way, they can effectively ‘read’ the activity of entire cell populations in brain tissue slices or live brains.

Calcium-sensitive dyes are injectable, so targeting them with precision is difficult, and more recently, researchers have developed genetically-encoded calcium sensors to overcome this limitation. Mice can be genetically engineered to express these calcium-sensitive proteins in specific groups of cells; like the dyes before them, they, too, fluoresce in response to increases in calcium ion concentrations in the cells expressing them.

Each of these methods is extremely powerful when used alone. Earlier this year, for example, researchers at MIT used optogenetics to label and then manipulate the neuronal populations encoding memories in the mouse brain, while a team at Janelia Farm used calcium imaging to visualise the firing of every single neuron in the embryonic zebrafish brain.

Adam Packer and his colleagues created a strain of mice expressing the Channelrhodopsin protein and an ultrasensitive calcium-binding protein in neurons in the barrel cortex, the part of the brain that receives sensory information from the whiskers. In this way, they could optogenetically activate specific cells while also using high-speed calcium imaging to visualise how they and other cells in the population react to stimulation, through transparent ‘windows’ scraped into the animals’ skulls.

The combination of methods enabled the researchers to determine which neurons contribute to a particular function, and then target them very precisely. To demonstrate the precision of the technique, they used a programmable device called a spatial light modulator that splits the light beam into a hologram consisting of smaller ‘beamlets’, and then simultaneously activated six neurons arranged in the shape of a smiley face.

There are other ways of simultaneously reading and writing neuronal activity, but they have drawbacks. Microelectrodes alone can be used to stimulate some cells and record from others, or stimulating electrodes can be combined with an imaging technique. This produces interference between the input and output channels, however, that can affect the results.

With the new approach, the frequency of light used to stimulate neurons does not overlap with that emitted by the calcium sensor, so there is minimal interference between the two channels, and the holographic light beam stimulates neurons with a ‘fast scanning’ procedure lasting just 2 femtoseconds (billionths of a second) further reduces the interference.

The experiments show that the new all-optical method can indeed be used to simultaneously record and interfere with the activity of neuronal populations. They also show that it can be used continuously over several weeks, or even months, in awake, behaving animals. The researchers will undoubtedly continue to develop and improve upon the method, in order to learn more about the link between brain and behaviour and decipher the corresponding neural codes.

“We’re excited about this,” says senior author Michael Hser. “It unites two revolutions in neuroscience and heralds a new era in which we can abandon electrodes and use light alone to probe neural circuits during behaviour.”