This article originally appeared on Medical Daily.
Smoking weed and coming down with a case of "the munchies" often go hand-in-hand. You ravenously go through packs of potato chips, candy, and any food within arms reach. Surprisingly, while getting high is associated with increased appetite, a recent study in the American Journal of Medicine has found marijuana smokers are more likely to have lower body weight and broken bones.
"Our research has shown that heavy users of cannabis have quite a large reduction in bone density compared with nonusers, and there is a real concern that this may put them at increased risk of developing osteoporosis and fractures later in life," said Stuart Ralston, lead researcher of the study, and professor at the University of Edinburgh's Centre for Genomic and Experimental Medicine, in a statement.
Heavy use was defined as those who smoked on 5,000 or more occasions in their lifetime. However, in this study, the average heavy pot smoker had taken the drug more than 47,000 times. On average, moderate users had taken the drug about 1,000 times.
Ralston and his colleagues examined the relationship between heavy pot use and bone health by using a specialized X-ray technique, known as dual-energy X-ray absorptiometry (DXA), to measure the bone density of the study participants. A total of 170 people who recreationally smoked cannabis regularly, and 114 nonusers, were assessed from 2011 to 2013. The researchers noted the correlation between heavy use and bone density.
Fractures were found to be more common in heavy users compared to nonusers, while moderate users showed no difference from nonusers. Bone density of heavy pot smokers was about 5 percent lower than cigarette smokers who did not smoke pot. Previous research has found a direct relationship between tobacco use and decreased bone density. Smoking increases the risk of having a fracture and has a negative impact on bone healing after fracture. This can lead to osteoporosis, a condition in which bones weaken and are more likely to fracture.
In addition, heavy pot smokers had a lower body weight and body mass index (BMI) than nonusers. Typically, smoking is associated with an increased appetite, but researchers believe pot suppresses appetite when taken in large quantities over a long period of time. In other words, many of marijuana's effects, like increased appetite, are reduced in frequent users, so the body adjusts to it.
Interestingly, this study contradicts a previous 2005 study in the Journal of Bone and Mineral Research that suggests marijuana could be good for bones. Researchers found the compound cannabinoid cannabidiol (CBD), which is a nonhallucinogenic chemical in marijuana plants, helps heal bone fractures. CBD enhanced bone healing by strengthening the cartilage “bridge” that forms when a bone is on the mend. This bridge is called the “fracture callus,” and made of collagen, which then gradually mineralizes and hardens into new bone. The collagen tissue was stronger, with collagen molecules more tightly cross-linked with one another compared to those who were not injected with CBD.
The effects of heavy marijuana use on bone health is still in its infancy stages. Further research is needed to investigate the underlying mechanisms between increased use and bone density. Nonetheless, these findings do have clinical implications in "identifying heavy cannabis use as potential cause of low bone mineral density, increased bone turnover and predisposition to fractures,” concluded the study authors.
This article originally appeared on Medical Daily.
Think back to one of your most fond, clear memories; it’s likely this experience occurred when you were between 15 and 25. According to an increasing number of psychologists, this isn’t pure coincidence. We aren’t sure why this memory bias exists, but one team of researchers in a recent study proposed it may be due to the development of our sense of self.
This phenomenon is called the “reminiscence bump” due to the shape it creates when plotted alongside other memories in a person’s lifespan. In a recent article published on The Conversation, psychologists Akira O’Connor, Chris Moulin, and Clare Rathbone explained their emerging research on why this bump exists, and proposed that memories are most clear between 15 and 25 because the age span signifies a point in our lives when we are developing who we are.
“Our findings suggest that the reason people remember more from that critical time in their lives is indeed because it is when their identities are forming,” wrote the researchers in their article published on The Conversation.
In order to determine this conclusion, the team conducted a series of experiments where they tested participants' ability to recall material. For example, in one experiment, participants were asked to consider songs and Oscar-winning films released between 1950 and 2005 to best gauge which part of their lives they remembered clearest. In every test, the team noticed the trend of biased recollection between the ages of 15 and 25.
While the team believe that this memory bias exists due to the development of self-awareness, they emphasize that their research does not necessarily rule out other theories. For example, some propose that this memory bias may be more biologically based, and may be linked to brain maturation in this period, The Conversation reported. Others suggest that we recall our “first” experiences the best, and many first experiences, such as a first kiss, first job, and so on, occur in this period. A last theory suggests that the memory bias is culturally based, as society tends to put high value on sharing and discussing events that occurred during this key period.
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Answer from Michael Lee, public policy analyst:
Speculation: climate change itself is far less controversial than what we should do about climate change. Also, the term “climate change” is now something of a code phrase for “what we should do about climate change,” which is no doubt why so many people deny the very existence of climate change in opinion polling. Leaving aside the snowball-on-the-Senate-floor crowd, it’s not that so many people actually think the climate is static, but that they’re interpreting the question as asking for their views of proposed actions on climate change!
So in order to get people to take climate change action more seriously, politicians should probably take those actions more seriously. In descending order of probability of success:Levy a carbon tax. No, I don’t love the idea of paying more in taxes, which is why I’d suggest that it replace the income tax over time, with appropriate progressivity provisions. But if climate change is truly the existential threat of our times, then we should take it seriously as a matter of public finance. Of course, higher gas taxes and the like are hideously unpopular, but I never said this was likely to happen.Develop strong international agreements. One of the biggest arguments against climate change action in the U.S. is that any reduction in carbon emissions that we can manage will be more than offset by increased emissions in developing countries. In effect, we’re sacrificing economic growth while other countries enjoy it, with no net effect on the global climate, and that’s a hard sell. (That’s not the whole picture, either: theoretically, we’d be validating mitigation strategies that could later proliferate in the developing world. But that’s still theoretical). It’s been a while since I looked at the details, but I understand that the famous Kyoto Protocol was woefully inadequate, and wouldn’t have even stabilized greenhouse gas emissions. That’s just not good enough.“Walk the walk.” Far too many global elites, including many politicians, think nothing of jetting off to their favorite destinations, living in gigantic homes, and driving anywhere they’d like (or perhaps more accurately, being chauffeured!) The media abound with tales of global climate change conferences with hundreds upon hundreds of private jets at the nearest airport, Hollywood stars inveighing against climate change and then flying off to European resorts, and otherwise reveling in carbon emissions-heavy lifestyle. Now, far be it from this Republican to quibble with how the wealthy spend their money! But it’s clearly a bit of a problem for all of those elites to advocate for solutions that they claim are—as Dylan Matthews of Vox describes carbon taxes—“literally necessary to save the planet”—when they won’t abide by them in their personal lives. More succinctly: when demanding that everyone sacrifice, one has more credibility by already sacrificing!
Of course, none of these are tremendously likely: carbon taxes are unpopular (so even if they were enacted, they’d likely be repealed rather quickly), international climate change agreements with any teeth are impossible to obtain (though that’s not a problem unique to climate change), and the world’s wealthy aren’t going to give up their lifestyles on the chance that they’ll convince the proletariat to cut back on carbon emissions.
It’s indeed something of a pickle.
How should politicians get citizens to take climate change more seriously? originally appeared on Quora—the knowledge-sharing network where compelling questions are answered by people with unique insights. You can follow Quora on Twitter, Facebook, and Google+. More questions:Climate Change: What is climate change and why is it important?Politics: Is Bernie Sanders dividing the Democratic Party?Environmentalism: Why conserve the environment?
The Northern Lights, the ethereal spectacle of swirling color caused by charged solar particles interacting with the Earth's magnetic field, was visible across swathes of the U.K. on Sunday night thanks to a “lucky combination” of conditions in the lower atmosphere and space, said the Met Office.
“Once in a while, the solar winds are enhanced to levels stronger than normal, with particles at higher speeds,” said the Met’s space weather adviser Amanda Townsend in a statement. “And on this occasion it has connected really well with the Earth’s magnetic field.”
Brits took to social media to share images of the illuminated sky.
Those who missed the Aurora Borealis this time might have to wait a while for the next display. “The strongest part of the geomagnetic storm has passed and it probably won't be as strong on Monday night,” Townsend added. “So the main places to see aurora will be in north Scotland.”
Updated | Scientists have attached the head of a smaller rat onto a larger one in the latest study by controversial neurosurgeon Sergio Canavero.
Images, which can be seen on Motherboard, show how three rats were used for the operation. One was the donor, the other recipient while the third provided the blood supply between the two. The resulting surgery shows how the smaller, donor rat’s head and forearms have been attached to the larger recipient’s.
Researchers released details of their findings in the journal CNS Neuroscience and Therapeutics , explaining how they developed a “bicephalic [having two heads] model of head transplantation” in order to study potential problems relating to insufficient blood flow to the brain and immune rejection.
The study, whose authors include Italian neurosurgeon Sergio Canavero and Xiaoping Ren from the Harbin Medical University, China, claims to show how a third rat can be used to “guarantee” blood supply during the operation. The donor rat was connected to the third rat via a silicone tube. This tube passed through a pump which provided a blood supply to the donor brain tissue during the transplant.
Sergio Canavero, who plans to carry out the world's first human head transplant in December this year. Russell Cheyne/Reuters
Researchers say there was no injury to the donor brain tissue and that following the operation, the donor had pain and corneal reflex. Concluding, they say that having a pump application during surgery provides a blood supply to the donor brain tissue, while the silicone tube protects it from hypothermia by regulating the temperature.
Canavero and Ren have carried out a series of head transplant experiments; in September 2016, the pair released three studies to New Scientist in which they claimed to show successful operations.
In one, the researchers claim to have severed 90 percent of a dog’s spinal cord before re-attaching it. In another, scientists used graphene nanoribbons to create a scaffold for neurons to grow along. The team claimed there was electrical activity the day after they cut the spinal cord, but most of the mice then died in a flood so follow-up observations were lacking. None of these papers were peer reviewed.
In January 2016, Canavero announced a successful monkey head transplant had been carried out by Ren in China. Images showing the head of a monkey stitched onto another were released, and Canavero claimed it survived for 20 hours without neurological damage before being euthanized for ethical reasons.
Canavero is currently planning to carry out the world’s first human head transplant in December 2017. Initially, the first patient was to be Valery Spiridonov, a Russian man who suffers from Werdnig-Hoffman's disease—a degenerative muscle wasting condition. However, it has now been announced—for reasons unknown—that Spiridonov will not be the first head transplant patient. Instead, Canavero said they will be a Chinese national who has yet to be selected.
“[There are] various candidates,” he said in a statement. “Which is not surprising, considering that a high number of volunteers from all over the world came forward. The final decision is only made immediately prior to the operation, as it also depends on the body donor, who has to be compatible with the receiver in many ways.”
The proposal has been met with huge criticism from the scientific community. Along with the major ethical issues such an operation raises, many have said Canavero’s technique will not work and there is not enough evidence to suggest an operation will be a success. Furthermore, should the operation fail, Spiridonov could technically be left conscious in a huge amount of pain.
When Canavero first announced the plan in 2015, Hunt Batjer, president elect of the American Association for Neurological Surgeons, commented: "I would not wish this on anyone. I would not allow anyone to do it to me as there are a lot of things worse than death."
This article originally stated that Canavero was currently planning to carry out the world’s first human head transplant in December 2017 on terminally ill Russian patient Valery Spiridonov. It has now been updated to say Canavero will be performing the operation on a Chinese national.
Updated | Many have dreamed of figuring out how to travel in time—and dismissed it as impossible. Now, researchers have proposed a mathematical model that makes time travel possible, using concepts of Einstein’s theory of general relativity coupled with the hypothesis that time is not a separate dimension.
Traditionally, we think of the universe as being made up of three spatial dimensions, and a fourth dimension representing time. But mathematician Ben Tippett at the University of British Columbia, Canada, says this is wrong. He believes time should not be separated from other three spatial dimensions—instead all four run together, simultaneously.
Working with David Tsang, an astrophysicist from the University of Maryland, he has worked out a way to use this principle to make time travel possible. Their findings have now been published in the journal Classical and Quantum Gravity.
“People think of time travel as something fictional,” Tippett said in a statement. “And we tend to think it’s not possible because we don’t actually do it. But, mathematically, it is possible.”
In an email interview with Newsweek , he explained how the time machine—Traversable Acausal Retrograde Domain in Spacetime, or TARDIS—would work. In general relativity, the curvature of spacetime causes gravity by exerting a force on objects passing them. These curves cause planets to orbit stars—if spacetime was not curved, all the planets and stars would travel along straight lines. So if spacetime is curved, and we run time along it simultaneously, then theoretically the bend can be turned into a loop, making time travel possible.
“Since the 1950s, there have been many other proposals for spacetimes which allow people to travel backward in time,” he says. “My work was to model a ‘time machine,’ where passengers inside of a box of limited size could travel along a circle through space and time, returning to their own pasts.
“The shape of spacetime was used to turn the direction of the arrow of time inside of the box in space and time. I then used Einstein’s theory to analyze this strange spacetime, and determine what would be required to build such a thing.”
Dr Who's TARDIS. Tippett called the machine the Traversable Acausal Retrograde Domain in Spacetime, or TARDIS. Giles Turnbull/CC
Tippet and Tsang’s time machine model creates a spacetime curvature that is bent into a circle. Anything—a box with someone inside, for example—moving along this curvature would be anchored to this version of time and would move backward. Someone watching from the outside would be able to see events running in reverse.
“It is because time and space are attached together that the time machine to behave in this way,” Tippet says. “In the simplest way, the orientation of the arrow of time inside the box is not anchored to the orientation of the arrow of time outside the box.
“Initially, they are pointing in the same direction; and then the direction of the arrow of time in the box turns so that ‘forward in time’ inside the box corresponds to the ‘sideways’ spatial direction outside of the box. And then the arrow of time inside the box continues to rotate in space and time until it returns to its original orientation.”
If you were inside the time machine making breakfast, the hands of your wristwatch would be moving forward and you would feel a “persistent acceleration,” Tippet explains. But if you were to look outside, things would get very strange.
“You would see two strange things: First you would see a second version of you standing in an identical copy of your box, but timeshifted (so, at a previous time), and also, time would be running in reverse. Your doppelgänger would be un-frying eggs, and putting them back in their shells; and un-stirring the cream from their coffee. The hands on the clocktower outside would behave erratically, first moving clockwise, then counterclockwise, according to which part of the bubble’s journey you were currently sitting through.
“The fun thing is that the outside viewer would see two version of you: One where time was moving forward in time (cracking and frying eggs) and the other moving backward in time (un-stirring the cream in their coffee).”
But will such a machine ever exist? Tippet says no. “Our paper included a careful analysis of this geometry, and the problems it would have in being built,” he says. “Generally speaking, backward time travel usually causes singularities (places where there are holes in the universe) or instabilities which would cause them to collapse into a black hole if they get poked the wrong way. So unfortunately, I don’t foresee this as being feasible."
Marika Taylor, professor of theoretical physics at the University of Southampton, commented on the study. She tells Newsweek over email: “Mathematical models for time travel all use the idea of creating shortcuts in a spacetime. In the study the authors explore a version of this idea, bubbles in a spacetime.
“However the main problems in all these models are that quantum effects [effects that cannot be explained by classical physics] often destroy the spacetime shortcuts and that exotic forms of matter are required to create the shortcuts.”
Exotic matter refers to a class of material yet to be discovered. Unlike ordinary matter, exotic matter causes space and time to expand and gravity to be repulsive. In the study, the researchers note that time can only be bent into a circle by using exotic matter.
Taylor continues: “The authors of this study are open about the fact that they have these problems too: their bubbles have to be supported by exotic forms of matter (matter that has never been found in Nature!), and there are ‘singularities’ in their spacetimes (which mean quantum physics effects are very important and may likely cause their bubbles to be unstable and collapse).
“So, in summary, while their work is interesting and adds to the existing literature, it doesn't really show that time travel is possible in our Universe. It is not clear that such exotic forms of matter actually can exist in our Universe (it's considered very unlikely).”
This piece has been updated to include comments from Marika Taylor.