Archive for the ‘Atlanta’ Category

pot

by Jon Hamilton

Veterans who smoke marijuana to cope with post-traumatic stress disorder may be onto something. There’s growing evidence that pot can affect brain circuits involved in PTSD.

Experiments in animals show that tetrahydrocannabinol, the chemical that gives marijuana its feel-good qualities, acts on a system in the brain that is “critical for fear and anxiety modulation,” says Andrew Holmes, a researcher at the National Institute on Alcohol Abuse and Alcoholism. But he and other brain scientists caution that marijuana has serious drawbacks as a potential treatment for PTSD.

The use of marijuana for PTSD has gained national attention in the past few years as thousands of traumatized veterans who fought in Iraq and Afghanistan have asked the federal government to give them access to the drug. Also, Maine and a handful of other states have passed laws giving people with PTSD access to medical marijuana.

But there’s never been a rigorous scientific study to find out whether marijuana actually helps people with PTSD. So lawmakers and veterans groups have relied on anecdotes from people with the disorder and new research on how both pot and PTSD works in the brain.

An Overactive Fear System

When a typical person encounters something scary, the brain’s fear system goes into overdrive, says Dr. Kerry Ressler of Emory University. The heart pounds, muscles tighten. Then, once the danger is past, everything goes back to normal, he says.

But Ressler says that’s not what happens in the brain of someone with PTSD. “One way of thinking about PTSD is an overactivation of the fear system that can’t be inhibited, can’t be normally modulated,” he says.

For decades, researchers have suspected that marijuana might help people with PTSD by quieting an overactive fear system. But they didn’t understand how this might work until 2002, when scientists in Germany published a mouse study showing that the brain uses chemicals called cannabinoids to modulate the fear system, Ressler says.

There are two common sources of cannabinoids. One is the brain itself, which uses the chemicals to regulate a variety of brain cells. The other common source is Cannabis sativa, the marijuana plant.

So in recent years, researchers have done lots of experiments that involved treating traumatized mice with the active ingredient in pot, tetrahydrocannabinol (THC), Ressler says. And in general, he says, the mice who get THC look “less anxious, more calm, you know, many of the things that you might imagine.”

Problems with Pot

Unfortunately, THC’s effect on fear doesn’t seem to last, Ressler says, because prolonged exposure seems to make brain cells less sensitive to the chemical.

Another downside to using marijuana for PTSD is side effects, says Andrew Holmes at the National Institute on Alcohol Abuse and Alcoholism. “You may indeed get a reduction in anxiety,” Holmes says. “But you’re also going to get all of these unwanted effects,” including short-term memory loss, increased appetite and impaired motor skills.

So for several years now, Holmes and other scientists have been testing drugs that appear to work like marijuana, but with fewer drawbacks. Some of the most promising drugs amplify the effect of the brain’s own cannabinoids, which are called endocannabinoids, he says. “What’s encouraging about the effects of these endocannabinoid-acting drugs is that they may allow for long-term reductions in anxiety, in other words weeks if not months.”

The drugs work well in mice, Holmes says. But tests in people are just beginning and will take years to complete. In the meantime, researchers are learning more about how marijuana and THC affect the fear system in people.

At least one team has had success giving a single dose of THC to people during something called extinction therapy. The therapy is designed to teach the brain to stop reacting to something that previously triggered a fearful response.

The team’s study found that people who got THC during the therapy had “long-lasting reductions in anxiety, very similar to what we were seeing in our animal models,” Holmes says. So THC may be most useful when used for a short time in combination with other therapy, he says.

As studies continue to suggest that marijuana can help people with PTSD, it may be unrealistic to expect people with the disorder to wait for something better than marijuana and THC, Ressler says. “I’m a pragmatist,” he says. “I think if there are medications including drugs like marijuana that can be used in the right way, there’s an opportunity there, potentially.”

http://www.npr.org/blogs/health/2013/12/23/256610483/could-pot-help-veterans-with-ptsd-brain-scientists-say-maybe

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cannonball run

Before the transcontinental race in “Cannonball Run,” the starter tells the gathered racers, “You all are certainly the most distinguished group of highway scofflaws and degenerates ever gathered together in one place.”

Ed Bolian prefers the term “fraternity of lunatics.”

Where the 1981 Burt Reynolds classic was a comedic twist on a race inspired by real-life rebellion over the mandated 55-mph speed limits of the 1970s, Bolian set out on a serious mission to beat the record for driving from New York to Los Angeles.

The mark? Alex Roy and David Maher’s cross-country record of 31 hours and 4 minutes, which they set in a modified BMW M5 in 2006.

Bolian, a 28-year-old Atlanta native, had long dreamed of racing from East Coast to West. A decade ago, for a high school assignment, Bolian interviewed Brock Yates, who conceived the Cannonball Baker Sea-To-Shining-Sea Memorial Trophy Dash, aka the Cannonball Run.

Yates, who played the previously quoted organizer in the film he wrote himself, won the first Cannonball in the early 1970s with a time of 35 hours and 53 minutes.

“I told him, ‘One day I’d like to beat your record,’ ” Bolian recalled.

It sounds like great outlaw fun — and certainly, Hollywood added its embellishments, like the supremely confident, infidel-cursing sheik with a Rolls Royce and Sammy Davis Jr. in a priest getup — but Bolian said it took considerable research and groundwork.

Beginning in 2009, about the time he started working for Lamborghini Atlanta, Bolian researched cars, routes, moon phases, traffic patterns, equipment, gas mileage and modifications.

He went into preparation mode about 18 months ago and chose a Mercedes CL55 AMG with 115,000 miles for the journey. The Benz’s gas tank was only 23 gallons, so he added two 22-gallon tanks in the trunk, upping his range to about 800 miles. The spare tire had to go in the backseat with his spotter, Dan Huang, a student at Georgia Tech, Bolian’s alma mater.

To foil the police, he installed a switch to kill the rear lights and bought two laser jammers and three radar detectors. He commissioned a radar jammer, but it wasn’t finished in time for the trek. There was also a police scanner, two GPS units and various chargers for smartphones and tablets — not to mention snacks, iced coffee and a bedpan.

By the time he tricked out the Benz, which included a $9,000 tuneup, “it was a real space station of a thing,” he said, describing the lights and screens strewn through the car’s cockpit.

Yet he still wasn’t done.

“The hardest thing, quite honestly, was finding people crazy enough to do it with me,” he said.

Co-driver Dave Black, one of the Atlanta Lamborghini dealership’s customers, didn’t sign on until three days before they left, and “support passenger” Huang didn’t get involved until about 18 hours before the team left Atlanta for Manhattan.

If his difficulty finding a copilot wasn’t an omen, Manhattan would deliver one. While scouting routes out of the city, a GPS unit told Bolian to take a right on red, in the wrong direction down a one-way road. He was quickly pulled over.

Bolian got a warning — and a healthy dose of relief that the officer didn’t question the thick odor of fuel as he stood over the vents pumping fumes from the trunk.

The trio ignored what some might have considered a harbinger and the left the Red Ball Garage on East 31st Street, the starting point for Yates’ Cannonball, a few hours later. To be exact, they left October 19 at 9:55 p.m., according to a tracking company whose officials asked not be identified because they were unaware that Bolian would be driving so illegally when he hired them.

They hit a patch of traffic in New York that held them up for 15 minutes but soon had an average speed of about 90 mph. In Pennsylvania, they tapped the first of many scouts, one of Bolian’s acquaintances who drove the speed limit 150 to 200 miles ahead of the CL55 and warned them of any police, construction or other problems.

They blew through Ohio, Indiana and Illinois, hitting St. Louis before dawn.

“Everything possible went perfect,” Bolian said, explaining they never got lost and rarely encountered traffic or construction delays.

By the time they hit southern Missouri, near the Oklahoma border, they learned they were “on track to break the existing record if they averaged the speed limit for the rest of the trip,” he said.

Yeah, right. This wasn’t about doing speed limits.

They kept humming west, and as they neared the Texas-New Mexico border, they calculated they might beat the 30-hour mark, a sort of Holy Grail in transcontinental racing that Bolian likened to the 4-minute mile.

Not one to settle, “we decided to break 29,” Bolian said.

The unnamed tracking company says the Benz pulled into the Portofino Hotel and Marina in Redondo Beach, California, at 11:46 p.m. on October 20 after driving 2,803 miles. The total time: 28 hours, 50 minutes and about 30 seconds.

“Most of the time, we weren’t going insanely fast,” Bolian said, not realizing his definition of “insanely” is a little different from most folks’.

When they were moving, which, impressively, was all but 46 minutes of the trip, they were averaging around 100 mph. Their total average was 98 mph, and their top speed was 158 mph, according to an onboard tracking device.

“Apart from a FedEx truck not checking his mirrors before he tried to merge on top of me, we didn’t really have any issues,” Bolian said.

He concedes his endeavor was a dangerous one, especially when you consider Bolian slept only 40 minutes of the trip, and co-driver Black slept an hour. But Bolian went out of his way to make it as safe as possible, choosing a weekend day with clear weather and a full moon — and routes, when possible, with little traffic or construction.

“I had plenty of people at home praying I’d make it safely, and, more importantly, had my wife praying that I wouldn’t have to do it again,” he said, adding he has no children, which was also a factor. “That was one of the spurs to go ahead and get this over with. That’s probably the next adventure.”

Asked if the technological advances since the previous record holders made their run gave him an advantage, Bolian replied, “Absolutely.” Because two teams broke the 32-hour mark in 2006 and 2007, he had a detailed “guide book” on how to do it, where they had to rely on word-of-mouth tales from the 1980s.

“I thank Alex for that. We’re all adding chapters to the same story of American car culture,” Bolian said. Alex Roy did not respond to an e-mail seeking comment.

Bolian had hoped to revisit that high school interview and tell Yates he’d followed through on that promise to break his record, but Yates now suffers from Alzheimer’s.

“I’ll pay him a visit just for the sake of it,” Bolian said, “but I can’t tell him.”

Where the Cannonball scofflaws aimed to make a statement about personal freedom, Bolian said he has the utmost respect for law enforcement. His goal was merely to “add myself and pay tribute to this chapter of automotive history,” he said.

Bolian also hopes that he shattered Roy’s record by such a stark margin that it discourages would-be Cannonballers from attempting to break his record, and it’s not just a matter of his own legacy, he said.

“It really isn’t something we need a whole band of lunatics doing,” he said.

http://www.cnn.com/2013/10/31/us/new-york-los-angeles-cannonball-speed-record/index.html?hpt=hp_c2

130222102958-large
The fruit fly study adds to the evidence “that using toxins in the environment to medicate offspring may be common across the animal kingdom,” says biologist Todd Schlenke.

When fruit flies sense parasitic wasps in their environment, they lay their eggs in an alcohol-soaked environment, essentially forcing their larvae to consume booze as a drug to combat the deadly wasps.

The discovery by biologists at Emory University was published in the journal Science on February 22.

“The adult flies actually anticipate an infection risk to their children, and then they medicate them by depositing them in alcohol,” says Todd Schlenke, the evolutionary geneticist whose lab did the research. “We found that this medicating behavior was shared by diverse fly species, adding to the evidence that using toxins in the environment to medicate offspring may be common across the animal kingdom.”

Adult fruit flies detect the wasps by sight, and appear to have much better vision than previously realized, he adds. “Our data indicate that the flies can visually distinguish the relatively small morphological differences between male and female wasps, and between different species of wasps.”

The experiments were led by Balint Zacsoh, who recently graduated from Emory with a degree in biology and still works in the Schlenke lab. The team also included Emory graduate student Zachary Lynch and postdoc Nathan Mortimer.

The larvae of the common fruit fly, Drosophila melanogaster, eat the rot, or fungi and bacteria, that grows on overripe, fermenting fruit. They have evolved a certain amount of resistance to the toxic effects of the alcohol levels in their natural habitat, which can range up to 15 percent.

Tiny, endoparasitoid wasps are major killers of fruit flies. The wasps inject their eggs inside the fruit fly larvae, along with venom that aims to suppress their hosts’ cellular immune response. If the flies fail to kill the wasp egg, a wasp larva hatches inside the fruit fly larva and begins to eat its host from the inside out.

Last year, the Schlenke lab published a study showing how fruit fly larvae infected with wasps prefer to eat food high in alcohol. This behavior greatly improves the survival rate of the fruit flies because they have evolved high tolerance of the toxic effects of the alcohol, but the wasps have not.

“The fruit fly larvae raise their blood alcohol levels, so that the wasps living in their blood will suffer,” Schlenke says. “When you think of an immune system, you usually think of blood cells and immune proteins, but behavior can also be a big part of an organism’s immune defense.”

For the latest study, the researchers asked whether the fruit fly parents could sense when their children were at risk for infection, and whether they then sought out alcohol to prophylactically medicate them.

Adult female fruit flies were released in one mesh cage with parasitic wasps and another mesh cage with no wasps. Both cages had two petri dishes containing yeast, the nourishment for lab-raised fruit flies and their larvae. The yeast in one of the petri dishes was mixed with 6 percent alcohol, while the yeast in the other dish was alcohol free. After 24 hours, the petri dishes were removed and the researchers counted the eggs that the fruit flies had laid.

The results were dramatic. In the mesh cage with parasitic wasps, 90 percent of the eggs laid were in the dish containing alcohol. In the cage with no wasps, only 40 percent of the eggs were in the alcohol dish.

“The fruit flies clearly change their reproductive behavior when the wasps are present,” Schlenke says. “The alcohol is slightly toxic to the fruit flies as well, but the wasps are a bigger danger than the alcohol.”

The fly strains used in the experiments have been bred in the lab for decades. “The flies that we work with have not seen wasps in their lives before, and neither have their ancestors going back hundreds of generations,” Schlenke says. “And yet, the flies still recognize these wasps as a danger when they are put in a cage with them.”

Further experiments showed that the flies are extremely discerning about differences in the wasps. They preferred to lay their eggs in alcohol when female wasps were present, but not if only male wasps were in the cage.

Theorizing that the flies were reacting to pheromones, the researchers conducted experiments using two groups of mutated fruit flies. One group lacked the ability to smell, and another group lacked sight. The flies unable to smell, however, still preferred to lay their eggs in alcohol when female wasps were present. The blind flies did not make the distinction, choosing the non-alcohol food for their offspring, even in the presence of female wasps.

“This result was a surprise to me,” Schlenke says. “I thought the flies were probably using olfaction to sense the female wasps. The small, compound eyes of flies are believed to be more geared to detecting motion than high-resolution images.”

The only obvious visual differences between the female and male wasps, he adds, is that the males have longer antennae, slightly smaller bodies, and lack an ovipositor.

Further experimentation showed that the fruit flies can distinguish different species of wasps, and will only choose the alcohol food in response to wasp species that infect larvae, not fly pupae. “Fly larvae usually leave the food before they pupate,” Schlenke explains, “so there is likely little benefit to laying eggs at alcoholic sites when pupal parasites are present.”

The researchers also connected the exposure to female parasitic wasps to changes in a fruit fly neuropeptide.

Stress, and the resulting reduced level of neuropeptide F, or NPF, has previously been associated with alcohol-seeking behavior in fruit flies. Similarly, levels of a homologous neuropeptide in humans, NPY, is associated with alcoholism.

We found that when a fruit fly is exposed to female parasitic wasps, this exposure reduces the level of NPF in the fly brain, causing the fly to seek out alcoholic sites for oviposition,” Schlenke says. “Furthermore, the alcohol-seeking behavior appears to remain for the duration of the fly’s life, even when the parasitic wasps are no longer present, an example of long-term memory.”

Finally, Drosophila melanogaster is not unique in using this offspring medication behavior. “We tested a number of fly species,” Schlenke says, “and found that each fly species that uses rotting fruit for food mounts this immune behavior against parasitic wasps. Medication may be far more common in nature than we previously thought.”

http://www.sciencedaily.com/releases/2013/02/130222102958.htm

sn-atmosphere

Each year, hundreds of millions of metric tons of dust, water, and humanmade pollutants make their way into the atmosphere, often traveling between continents on jet streams. Now a new study confirms that some microbes make the trip with them, seeding the skies with billions of bacteria and other organisms—and potentially affecting the weather. What’s more, some of these high-flying organisms may actually be able to feed while traveling through the clouds, forming an active ecosystem high above the surface of the Earth.

The discovery came about when a team of scientists based at the Georgia Institute of Technology in Atlanta hitched a ride on nine NASA airplane flights aimed at studying hurricanes. Previous studies carried out at the tops of mountains hinted that researchers were likely to find microorganisms at high altitudes, but no one had ever attempted to catalog the microscopic life floating above the oceans—let alone during raging tropical storms. After all, it isn’t easy to take air samples while your plane is flying through a hurricane.

Despite the technical challenges, the researchers managed to collect thousands upon thousands of airborne microorganisms floating in the troposphere about 10 kilometers over the Caribbean, as well as the continental United States and the coast of California. Studying their genes back on Earth, the scientists counted an average of 5100 bacterial cells per cubic meter of air, they report in the Proceedings of the National Academy of Sciences. Although the researchers also captured various types of fungal cells, the bacteria were over two orders of magnitude more abundant in their samples. Well over 60% of all the microbes collected were still alive.

The researchers cataloged a total of 314 different families of bacteria in their samples. Because the type of genetic analysis they used didn’t allow them to identify precise species, it’s not clear if any of the bugs they found are pathogens. Still, the scientists offer the somewhat reassuring news that bacteria associated with human and animal feces only showed up in the air samples taken after Hurricanes Karl and Earl. In fact, these storms seemed to kick up a wide variety of microbes, especially from populated areas, that don’t normally make it to the troposphere.

This uptick in aerial microbial diversity after hurricanes supports the idea that the storms “serve as an atmospheric escalator,” plucking dirt, dust, seawater, and, now, microbes off Earth’s surface and carrying them high into the sky, says Dale Griffin, an environmental and public health microbiologist with the U.S. Geological Survey in St. Petersburg, Florida, who was not involved in the study.

Although many of the organisms borne aloft are likely occasional visitors to the upper troposphere, 17 types of bacteria turned up in every sample. Researchers like environmental microbiologist and co-author Kostas Konstantinidis suspect that these microbes may have evolved to survive for weeks in the sky, perhaps as a way to travel from place to place and spread their genes across the globe. “Not everybody makes it up there,” he says. “It’s only a few that have something unique about their cells” that allows them survive the trip.

The scientists point out that two of the 17 most common families of bacteria in the upper troposphere feed on oxalic acid, one of the most abundant chemical compounds in the sky. This observation raises the question of whether the traveling bacteria might be eating, growing, and perhaps even reproducing 10 kilometers above the surface of Earth. “That’s a big question in the field right now,” Griffin says. “Can you view [the atmosphere] as an ecosystem?”

David Smith, a microbiologist at NASA’s Kennedy Space Center in Florida, warns against jumping to such dramatic conclusions. He also observed a wide variety of microbes in the air above Oregon’s Mount Bachelor in a separate study, but he believes they must hibernate for the duration of their long, cold trips between far-flung terrestrial ecosystems. “While it’s really exciting to think about microorganisms in the atmosphere that are potentially making a living, there’s no evidence of that so far.”

Even if microbes spend their atmospheric travels in dormancy, that doesn’t mean they don’t have a job to do up there. Many microbial cells are the perfect size and texture to cause water vapor to condense or even form ice around them, meaning that they may be able to seed clouds. If these microorganisms are causing clouds to form, they could be having a substantial impact on the weather. By continuing to study the sky’s microbiome, Konstantinidis and his team hope to soon be able to incorporate its effects into atmospheric models.

http://news.sciencemag.org/sciencenow/2013/01/microbes-survive-and-maybe-thriv.html