A pulsar orbited by a white dwarf star, which are both orbited by another white dwarf, provide confirmation of the principle of universality of free fall



Download 221.74 Kb.
Page2/6
Date conversion08.07.2018
Size221.74 Kb.
1   2   3   4   5   6

No high, but healing?
The cannabis plant produces hundreds of different compounds, many of which have differing effects in the body. Tetrahydrocannabinol, or THC, is the substance that is most known for its psychoactive effects, or the “high” associated with marijuana.

However, there are many other substances from the cannabis plant that also produce effects in the body. Many of these differ from THC in that they are not psychoactive – and they do not produce a “high.” Cannabidiol, or CBD, is one of those substances.


Credit: Getty Images
Cannabidiol is a complex molecule that is produced by the cannabis plant. Cannabis has been proposed for centuries as a medicinal plant. Only recently has CBD been studied scientifically for various disorders.

Compared to THC, CBD works at different receptors in the brain and other parts of the body. In this way, CBD is very different from THC and may offer new mechanisms of treatment. For this reason, CBD has received a great amount of attention as a possible treatment for many different disorders.

CBD has been proposed as a cure or treatment for many disorders and diseases, including epilepsy, chronic pain, anxiety, multiple sclerosis, amyotropic lateral sclerosis (ALS or Lou Gehrig’s disease) and insomnia. Some of these uses are based on science, but others are proposed by advocates of CBD and medical marijuana. Several anecdotal reports, case reports, case series and small studies have reported on CBD for many of these disorders. Information from these reports is conflicting. Case reports, case series and small studies are considered insufficient evidence to prove or disprove the safety and efficacy of a drug or treatment. This is because these studies are usually unable to distinguish between the effect of a drug and a placebo effect, the patient thinking the drug is working when it really is not providing benefit.

However, there are two well-designed, large studies that indicate CBD is effective in the two different epilepsy syndromes. In these studies, about 40 percent of patients taking CBD had a significant reduction in specific types of seizures.



RELATED: Cannabis-Based Medicine Dramatically Reduces Epileptic Seizures

Epilepsy is the only disorder where there is solid scientific evidence demonstrating that CBD is safe and effective. This does not mean that CBD will not work for other disorders, but epilepsy is the only one where we have clear, well-documented evidence that CBD helps.

Results from these studies show that CBD does have side effects. The most common ones are drowsiness, nausea, intestinal cramping, bloating and diarrhea. More serious side effects can occur. In one of the studies in epilepsy, about 10 percent of patients taking CBD had an increase in laboratory tests of liver function. These tests commonly indicate damage to the liver. About 2-3 percent of patients taking CBD had to discontinue it due to large increases in certain liver enzymes in laboratory tests, showing possible liver damage.

We are also learning about drug interactions that occur with CBD. In these studies, CBD slowed the metabolism of several drugs that are commonly given to individuals with epilepsy. The interactions between CBD and other drugs patients were taking caused side effects. It is unclear if these side effects were due to CBD, the other drugs, or a combination. Doses of the other drugs were reduced, due to the interactions.

The mechanism for these interactions indicate that there are likely several other interactions between CBD and other common medications. Cannabidiol needs to be used cautiously in combination with other medications.

Issues beyond effectiveness
There are several other factors to consider in regards to CBD. Cannabidiol does not dissolve well in water. For this reason, oral products of CBD are made with an oil, often some type of vegetable oil. It is important that the right oil is used.

Also, less than 20 percent of an oral dose of CBD is absorbed. This makes it difficult to produce a CBD product where CBD is reliably and consistently absorbed.



RELATED: Cannabis Compound May Restore Learning and Memory in People With Schizophrenia

An FDA study of unregulated CBD products available on the market shows these products are frequently contaminated with things like pesticides, herbicides, fungus or bacteria. Additionally, the FDA found that over 50 percent of CBD products may not contain the amount of CBD on the label. This is especially true in states where CBD products are not regulated by the state. In 17 states where there is regulation, there is much better control on product quality and purity.

Finally, there are two pharmaceutical-grade CBD products that have been studied for production by a pharmaceutical company. One is Epidiolex, and the other is still being studied.

So far, the evidence is that CBD is safe and effective for specific epilepsy syndromes. There is insufficient scientific evidence to indicate whether it is effective or ineffective for other disorders. Information from well-designed studies do indicate that CBD causes important side effects and drug interactions that must be considered. Individuals who wish to use CBD should be managed and monitored by health care professionals familiar with its use.



This article originally appeared at The Conversation.

]]>http://www.seeker.com/node/5014291?utm_medium=RSS&utm_source=feeds
Thu, 28 Jun 2018 15:58:12 -0500
The telescope will allow astronomers to study some of the earliest stars and galaxies in the universe, as well as hunt for alien life.no-reply@thrillist.com Mike Wall, Space.comMike Wall, Space.comhttp://www.seeker.com/space/nasa-delays-launch-of-james-webb-space-telescope-to-2021?utm_medium=RSS&utm_source=feeds Credit: Chris Gunn/NASA
NASA has delayed the launch of its huge, highly anticipated James Webb Space Telescope by another 10 months.

The liftoff of Webb, the successor to the agency's iconic Hubble Space Telescope, has been pushed back from May 2020 to March 2021, NASA officials announced June 27. The project's development cost has risen from $8 billion to $8.8 billion, and its total lifecycle price tag now stands at $9.66 billion, they added.

The rescheduling is the latest in a series of delays for Webb, which NASA had originally hoped to get off the ground way back in 2007. [Photo Tour: Building NASA's James Webb Space Telescope]

"We have to get this right here on the ground before we go to space," Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate, said during a news conference today. "And I just want to re-emphasize: Webb is worth the wait."



Rocky road for a complex observatory
Webb is a multipurpose observatory that will allow astronomers to study some of the first stars and galaxies in the universe, hunt for possible signs of life in the atmospheres of nearby alien planets, and do a variety of other high-profile work. Its primary mirror is 21.3 feet (6.5 meters) wide, compared to 7.8 feet (2.4 m) for that of Hubble.

"Webb is vital to the next generation of research beyond NASA's Hubble Space Telescope," NASA Administrator Jim Bridenstine said in a statement. "It's going to do amazing things — things we've never been able to do before — as we peer into other galaxies and see light from the very dawn of time."


Credit: Northrop Grumman
Webb is optimized to view the heavens in infrared light, and its instruments must therefore be kept quite cool. So the telescope will sport a giant sunshield the size of a tennis court, which will unfold after Webb reaches its final destination, a gravitationally stable spot about 930,000 miles (1.5 million kilometers) from Earth.

The road to that destination has been quite bumpy to date. Webb is a very complex observatory that has proved difficult for primary contractor Northrop Grumman to build and test, as the repeated delays attest.

Until relatively recently, NASA had been targeting an October 2018 launch. In September of last year, however, NASA announced that spacecraft-integration issues had delayed the launch until spring 2019. Then, this past March, the agency pushed the scheduled liftoff date back again, to May 2020. More time was needed to test Webb's intricate systems and to deal with setbacks, such as small tears in the sunshield, NASA officials said at the time.

The agency also set up an independent review board (IRB) in March to monitor the observatory's progress and develop recommendations. The IRB submitted its report to NASA on May 31, and the agency wrapped up its response to that report June 26. (You can read both the report and NASA's response here.)



Going forward
The IRB traced the 29-month delay (from a targeted launch date of October 2018 to March 2021) to five factors: human error, "embedded problems," excessive optimism, systems complexity, and a lack of experience in key areas, such as sunshade development.

IRB Chairman Tom Young laid out some of the most significant human errors during today's news conference. Technicians used the wrong solvent to clean propulsion valves, employed improper wiring that caused excessive voltage to be applied to transducers, and improperly installed sunshield-cover fasteners ahead of a key test, he said.

"All simple fixes that were not implemented resulted in approximately a 1.5-year schedule delay, at a cost of about $600 million," said Young, the former director of NASA's Goddard Space Flight Center in Greenbelt, Maryland, and the former president and chief operating officer of aerospace company Martin Marietta, which merged with Lockheed Corporation in 1995, forming Lockheed Martin.

The IRB report was key in NASA's latest plan for Webb, agency officials said. Indeed, the review panel made 32 separate recommendations for the observatory's development going forward, 30 of which NASA fully agrees with, Zurbuchen said. The agency is still considering the other two, he added.

Crucially, the IRB did not recommend pulling the plug on the telescope.

"With all the factors that I've discussed considered, the IRB believes that JWST should continue, because of the compelling science, and because of JWST's national importance," Young said.  

The bump in the mission's development cost from $8 billion to $8.8 billion may complicate that vision, however. The former number was a cap imposed by Congress, meaning that Webb needs another signoff from Capitol Hill to proceed.

"We submit our final 'breach report' to Congress this week," NASA Associate Administrator Steve Jurczyk said during today's news conference. "And then, it is true that Congress will have to reauthorize Webb through this next cycle of appropriations."



Originally published on Space.com.

Editor's Recommendations
Most Amazing Hubble Space Telescope Discoveries
How NASA's James Webb Space Telescope Works (Infographic)
Photos: Hubble's Successor, the James Webb Space Telescope

]]>
http://www.seeker.com/node/5014281?utm_medium=RSS&utm_source=feeds
Thu, 28 Jun 2018 14:48:54 -0500
Citing social stigmatization around opioid use, patients are turning to electronic nerve stimulation, meditation, and medical marijuana. no-reply@thrillist.com Glenn McDonaldGlenn McDonaldhttp://www.seeker.com/health/opioid-users-seek-alternatives-like-meditation-and-medical-marijuana?utm_medium=RSS&utm_source=feeds Credit: Liz O. Baylen/Los Angeles Times via Getty Images
A national survey released June 21 suggests that the opioid crisis is triggering a dilemma for those who live with chronic pain.
 
The dangers of opioid use — and the growing stigma around the medication — has prompted legitimate patients to look for other kinds of pain therapy, according to the study. But alternatives can be hard to find because the medical community has been relying on opioids for so long.
 
The survey suggests a kind of vicious catch-22 for those who need pain therapy, even if they don't have any abuse or addiction problems with opioids.
 
Conducted by the independent market research firm Vanson Bourne, the survey was commissioned by NeuroMetrix, a healthcare company that makes wearable devices to treat chronic pain, sleep disorders, and diabetes. The company also makes the digital device Quell, an over-the-counter wearable device that uses electric stimulation for treating chronic pain.
 
Clearly, NeuroMetrix has a stake in investigating market responses to alternative pain therapies. But the company has fully disclosed the survey's sponsorship and methodology — and the numbers reveal some interesting trends.
 
According to the survey, 84 percent of respondents — all of whom identified as chronic pain sufferers — believe that there is now a significant stigma around opioid use. Fifty percent said they felt personally stigmatized, and fifty percent also said they had lied in the past about their opioid use because of attitudes toward the drug. The study surveyed 1,500 adults in the United States between the ages 25 and 70.
 
RELATED: Opioid Overdoses in the US Rose 30 Percent in a Year
 
The respondents report that increasingly negative attitudes toward opioids have impacted their own treatment programs. Thirty-four percent of those surveyed said they have had to stop taking opioids because their doctors would no longer prescribe them.
 
“I think that the most significant finding is that the stigma around opioids and recent restrictions is affecting the care that chronic pain sufferers receive, forcing them to take care into their own hands, with 90 percent actively seeking new treatments,” said Frank McGillin of NeuroMetrix.
 
Of those alternative solutions, the survey identified the ten most common non-opioid treatment methods. Physical therapy was the most common, with 65 percent of respondents having undergone PT regimens. Forty-four percent said they have tried transcutaneous electrical nerve stimulation — like the Quell device — which send electrical currents across the surface of the skin to activate the underlying sensory nerves.
 
Thirty-two percent of respondents said they have tried herbal remedies or natural supplements, and 16 percent said they have used medical marijuana.
 
Other treatment methods include yoga/pilates/meditation (28 percent), acupuncture (21 percent), and cognitive behavioral therapy (16 percent).
 
McGillin said that he hopes the survey will help spur discussion about including the chronic pain patient in the national conversation taking place around the opioid crisis.
 
“There are 100 million Americans who have chronic pain and a significant number are being impacted by the opioid crisis, directly or indirectly,” he said. “We need to make sure that they have options to manage their pain so they can maintain or improve the quality of their lives.”

]]>
http://www.seeker.com/node/5014200?utm_medium=RSS&utm_source=feeds
Wed, 27 Jun 2018 15:49:52 -0500
In an effort to deal with its own waste management problems, China has limited imports of plastic and paper waste — and that’s having ripple effects across the globe.no-reply@thrillist.com Matt SmithMatt Smithhttp://www.seeker.com/earth/chinas-ban-on-imported-scrap-is-scrambling-recycling-efforts?utm_medium=RSS&utm_source=feeds Credit: AAron Ontiveroz/The Denver Post via Getty Images
China’s decision to stop taking in much of the world’s scrap paper and plastics has left those wastes piling up worldwide, with ripple effects that can reach as far as your curbside bins.

From the late 1980s until 2016, China took in nearly half of the world’s plastic waste, with the European Union and the United States the leading exporters. But as its own population became more prosperous, the Chinese began to struggle with their own waste and pollution issues.

So in late 2017, Beijing decided it had had it up to here with your scrap and wasn’t going to take it anymore. Since January, that “National Sword” policy has banned imports of most commercial plastic scrap, such as bottles and packaging. And unless something changes, the world is likely to have big piles of polymer waste piling up for decades to come, according to a new study of the ban’s impact.

“We’re having a big domino effect, a big cascading effect globally from this,” said Amy Brooks, the study’s lead author. “There have been reports all over of plastic waste accumulating within the borders of countries that have been largely relying on exporting their waste to China.”

It’s bad enough that less than 10 percent of the world’s plastics have been recycled, as a 2017 study found. But using trade data from the United Nations, Brooks and her colleagues at the University of Georgia project that other countries will have to find someplace else for up to 111 million metric tons of plastic by 2030 — or make some changes in what we do with the stuff.

“The question is, what are we going to do with all that plastic now?” said Brooks, a Ph.D. candidate in engineering. “It’s definitely putting more pressure on landfills and recycling facilities to figure that out.”



RELATED: Struggling to Process Its Own Waste, China Bans Imports of Recyclables

Brooks said plastic imports increased China’s waste by about 10 to 13 percent. About 90 percent of the imports were single-use items like plastic bottles or food containers.

The plastic ban was accompanied by strict limits on paper, with the country refusing to accept shipments of newsprint or cardboard with more than 5 kilograms (11 pounds) per ton of other wastes mixed in. US recyclers say that’s an all-but-impossible standard to meet. Prices for the material have plunged and processing costs have gone up, according to the industry â€” and as a result, some of the paper and plastic Americans are trying to recycle are ending up in landfills.

Plastic in particular has ben difficult to manage, Marjorie Griek, executive director of the National Recycling Coalition, told Seeker.

“We here in this country kind of lost the capability to handle those materials because China was such a voracious consumer,” said Griek, whose Colorado-based organization represents small recyclers, local governments, and nonprofits. “Everyone said, ‘They’ll take it, they’ll pay us a good price, it doesn’t cost us much to get it there, and they’re really happy with it.’ So it’s a bit of a change for everyone in the industry to have to rethink this.”

Recyclers are seeking new overseas markets for the scrap they process, “but they’re certainly not going to consume what China consumes.”

That’s starting to hit the budgets of cities and counties that promote recycling as well. In El Paso, Texas, the company that handles the city’s recycling has asked the city council for a more than 50 percent increase in fees to cover their costs, said Kurt Fenstermacher, deputy director of the city’s Environmental Services Department.

The council has put off action on the request, which would raise the fees paid from about $75 to $115 a ton, Fenstermacher told Seeker. Instead, it’s trying to work with the recycler to help reduce its costs.

In a pilot program in several neighborhoods, city inspectors walk the streets ahead of the recycling trucks to inspect the blue recycling bins for non-recyclable items like plastic bags or trash, which can jam up equipment or force the processor to spit out otherwise-recyclable material. When they find them, they attach an “Oops tag” to the bin to remind the household what’s acceptable and what’s not.

“We see a lot of plastic bags and bagged material in the blue bins,” Fenstermacher said. “It’s down time for them, and every minute of production is important for them,” “We’re doing our part to try to keep that material flowing through their system as cleanly as we can.”



RELATED: A New Way of Making Plastic Could Help Boost Recycling

In Lancaster County, Pennsylvania, west of Philadelphia, between 20 and 40 percent of what ends up in curbside bins is non-recyclable trash, said Kathryn Sandoe, a spokeswoman for the Lancaster County Solid Waste Management Authority. That means the local recycling processor has found about a third of the material it takes in is no longer marketable.

“The financial impact at the household level will only be a few bucks a year,” Sandoe said. But for companies that collect and process recyclables, “This is a financial crisis for them. They’re losing a significant amount of money.”

Meanwhile, Griek said, materials piling up can become homes to critters like rats or mosquitoes, which carry disease. And plastic piled outside begins to degrade in the sun’s ultraviolet light, making it less valuable.

The Chinese ban has spurred a few companies to explore building new plastic recycling plants or expanding existing ones in the United States, she said. A few recyclers are rethinking the common “single-stream” practice of collecting all materials together, requiring households to separate plastic and paper from other materials like aluminum before putting them out to the curb. Others are hiring more people to sort collections.

Communities that have “dual-stream” programs where paper and other recyclables are separated end up with in cleaner, more valuable paper to recycle. But most infrastructure, starting with the trucks that collect the bins, is designed for single-stream programs, Sandoe said.



RELATED: Giant Larvaceans Sweep Up and Poop Out Plastic Waste in the Oceans

Brooks said much of the expected tonnage is likely to end up in developing countries that don’t have the recycling infrastructure that China built, raising the odds that it will end up in landfills there.

“I think this is kind of a wake-up call that we need domestic capabilities to manage our waste, and there probably needs to be an economic policy that drives that,” she said. Changing the types of plastics produced, finding new materials or promoting more multi-use items may help head off that wave of debris.

“It makes a difference when millions of people decide to use a recyclable water bottle or a reusable bag,” she said. “I think a combination of technology, a combination of policy and consumer behavior all work toward the common goal of reducing plastic in the environment.”  

]]>http://www.seeker.com/node/5014187?utm_medium=RSS&utm_source=feeds


Wed, 27 Jun 2018 15:01:53 -0500
Seeker's Bad Science podcast explores the science behind the 2009 reboot of the venerable sci-fi series. no-reply@thrillist.com Glenn McDonaldGlenn McDonaldhttp://www.seeker.com/culture/set-phasers-to-stun-the-science-behind-star-trek?utm_medium=RSS&utm_source=feeds
It's hard to believe that nearly a decade has passed since director J.J. Abrams delivered his hugely anticipated reboot of the Star Trek movie series. The 2009 film, titled simply Star Trek, was a massive commercial success and it introduced a new generation to the crew of the Starship Enterprise.

But how does the real science behind the movie hold up?

Pretty good, actually.

In the latest episode of Bad Science, Seeker's podcast on science versus fiction at the movies, host Ethan Edenburg goes where no one has gone before with an hour-long special on the 2009 reboot and the Star Trek universe in general.

Also pitching in for this week's show: Seeker's own science savant Trace Dominguez and Tammy Ma, experimental physicist with the Lawrence Livermore National Laboratory.

The Star Trek franchise is particularly well-respected in the scientific community for getting its facts straight relative to the demands of Hollywood entertainment and speculative fiction. Apart from the hard physics of space travel and energy weapons, creator Gene Roddenberry's enduring vision regularly explores the topics of ethics in science, sociology, and anthropology.

Ma works with the most powerful lasers on the planet at her lab, located at Livermore's National Ignition Facility. The lasers operate at temperatures hotter than the sun’s core. Happily for everyone involved, these temperature flashes are extremely tiny and extremely brief. But still.

“On a daily basis we create the hottest place in the solar system,” Ma says. “We make miniature stars in the lab.”


In fact, several scenes from the film’s sequel Into Darkness were filmed at the National Ignition Facility.

“Our target chamber, where we do all our experiments, that was actually the warp core for the Starship Enterprise,” Ma says.

Dominquez and Ma also dig into some of the real-life challenges behind the core concept of the Star Trek franchise — traveling through space, exploring strange new worlds and seeking out new life and new civilizations. Discussion ranges from the possibility of fusion energy engines to the practical challenges of putting the International Space Station into orbit.

For hardcore fans of the 2009 film, the team also digs deep into script’s plot points — and plot holes. For instance, why does the villain Captain Nero need to drill down into the center of a planet to drop his artificial black hole bombs? And why does the future Earth of the Star Trek series lack any perimeter planetary defenses?

Tune into this week's episode for speculation on these enduring mysteries, plus more details on inertial fusion energy, particle physics, and Vulcan mind melds.

]]>http://www.seeker.com/node/5014131?utm_medium=RSS&utm_source=feeds


Tue, 26 Jun 2018 16:54:52 -0500
Experiments aboard the International Space Station will test a new method for dealing with space junk. no-reply@thrillist.com Elizabeth HowellElizabeth Howellhttp://www.seeker.com/space/theres-a-garbage-problem-in-space-a-harpoon-and-net-may-be-the-answer?utm_medium=RSS&utm_source=feeds Credit: Airbus
An experiment aboard the International Space Station could help engineers figure out how to one day take out the accumulating amount of trash in orbit.

Engineers will perform exercises later this year in which they will use cameras and laser guidance to capture objects with a harpoon and net attached to a spacecraft, called RemoveDEBRIS.

"Our experiments should start in September or October and they might last three or four months," principal investigator Guglielmo Aglietti told Seeker. Aglietti is director of the Surrey Space Center at the University of Surrey in the United Kingdom. The center is managing the mission and also constructed the microsatellites that RemoveDEBRIS will collect during the experiments.

Aglietti said the timing of the experiments is highly dependent on sufficient illumination from the sun.

Humans have been putting objects in orbit since 1957. That’s resulted in an estimated 500,000 pieces of debris circling Earth, including objects as large as dead satellites to ones as small as screws.

Because orbiting debris travels at high speed, it often poses a serious threat to operations in space. In 2009, the defunct Russian satellite Cosmos-2251 smashed into the operational Iridium 33 satellite. And engineers periodically adjust the orbit of the International Space Station in order to dodge space debris.


Credit: Airbus
Scientists have proposed several ideas for dealing with inoperative satellites, including refueling them, deploying garbage collecting robots, or even enveloping space junk with ultrathin sheets of solar-powered material that will burn up on reentry into Earth's atmosphere.

"We were searching for a test that was cost-effective," Aglietti said. "For example, you can fly to capture space debris using a robot arm. It's a good solution, but it is a more complex solution and more expensive."

A consortium of European companies are involved in the $17.5 million project, including Airbus, which developed the harpoon and net technology, and Surrey Satellite Technology Ltd., which worked on the avionics. Half of the funding for the experiments was provided by private-sector companies, with the European Commission covering the rest.

1   2   3   4   5   6


The database is protected by copyright ©dentisty.org 2016
send message

    Main page