Mammoth Fossils Found at Site of LA Subway Dig

Fossils from giant, ice age-beasts were uncovered while workers were digging an extension to the Los Angeles subway system.

The finds include a 3-foot-long (1 meter) section of mammoth tusk, as well as a skull and partial tusks from a much younger animal, which might have been either a mammoth or a mastodon, according to The Source, a transportation blog about the L.A. Metro.

Though the ice-age fossils (whose exact age has not yet been determined) are certainly treasures that are rarer to unearth under the subway than rat "fossils" and "coprolites," old chicken wings or discarded coffee cups, the finds actually aren't all that surprising. The area around the site of the fossil discovery, near the La Brea/Wilshire station, is not too far from the La Brea Tar Pits, an area of central Los Angeles where natural asphalt has been seeping up from the ground for the last 40,000 years.

Over the eons, this constant ooze of asphalt has created sticky pits in valleys that would often become obscured by leaves, branches and other ground cover. As a result, unwary animals stepped into the sticky death traps. The viscous ooze trapped small animals and insects immediately, while larger beasts like mammoths sank inches into the tar, struggling to get out before becoming stuck, researchers have noted. The dead or dying animals attracted predators as well — some of which also became stuck in the asphalt. All told, more than 1 million fossils have been found in the tar pits, according to the La Brea Tar Pits & Museum.

Mammoths and mastodons are both Proboscideans. Though both were majestically large and had shaggy coats and impressively curved tusks, mammoths are much more closely related to modern-day elephants, having arisen about 5 million years ago in Africa. By contrast, mastodons arose about 27 million to 30 million years ago. 

During the Pleistocene epoch, between 1.8 million and 11,700 years ago, mammoths and mastodons roamed over the part of North America that was not covered by ice sheets, including coastal California. [Skin & Bones: Look Inside Baby Mammoths]

Because of the subway line project's proximity to the La Brea Tar Pits, Metro officials were anticipating fossil finds and brought on paleontologists from the firm Cogstone to make sure that any discovery of prehistoric fossils would be safely excavated and preserved, according to the blog post. The new finds were immediately covered with plaster for preservation and sent to the nearby Natural History Museum of Los Angeles County.

How Lasers and a Goggle-Wearing Parrot Could Aid Flying Robot Designs

A barely visible fog hangs in the air in a California laboratory, illuminated by a laser. And through it flies a parrot, outfitted with a pair of tiny, red-tinted goggles to protect its eyes.

As the bird flaps its way through the water particles, its wings generate disruptive waves, tracing patterns that help scientists understand how animals fly.

In a new study, a team of scientists measured and analyzed the particle trails that were produced by the goggle-wearing parrot's test flights, and showed that previous computer models of wing movement aren't as accurate as they once thought. This new perspective on flight dynamics could inform future wing designs in autonomous flying robots, according to the study authors. 

When animals fly, they create an invisible "footprint" in the air, similar to the wake that a swimmer leaves behind in water. Computer models can interpret these air disturbances to calculate the forces that are required to keep a flyer aloft and propel it forward.

A team of scientists had recently developed a new system that tracked the airflow generated by flight at an unprecedented level of detail. They wanted to compare their improved observations to several commonly used computer models that use wake measurements to estimate flying animals' lift, to see if their predictions would be on track.

Flight of the parrotlet

For the study, the researchers enlisted the help of a Pacific parrotlet — a type of small parrot — named Obi. Obi was trained to fly between two perches that are positioned about 3 feet (1 meter) apart, through a very fine mist of water droplets, which are illuminated by a laser sheet. The water particles that seeded the air were exceptionally small, "only 1 micron in diameter," said study author David Lentink, an assistant professor of mechanical engineering at Stanford University in California. (In comparison, the average strand of human hair is about 100 microns thick.)

Obi's eyes were protected from the laser's light with custom goggles: a 3D-printed frame that is fitted with lenses cut from human safety glasses — the same type of glasses worn by Lentink and his team.

When the laser flashed on and off — at a rate of 1,000 times per second — the water droplets scattered the laser's light, and high-speed cameras shooting 1,000 frames per second captured the trails of disturbed particles as Obi fluttered from perch to perch.

The tests showed something unexpected. Computer models predicted that once the whirling air patterns — also known as vortices — were created by a bird's wings, they would remain relatively stable in the air. But the patterns Obi traced began to disintegrate after the bird flapped its wings just a few times.

"We were surprised to find the vortices that are usually drawn in papers and text books as beautiful donut rings turned out to break up dramatically after two to three wing beats," Lentink told Live Science in an email. He explained that this meant the models, which are widely used in animal flight studies to calculate an animal's lift based on the wake it produced, were likely inaccurate.

"Thanks to the high-speed recording, we were able to capture this and play it back in slow motion, so we could see with our eyes how the vortices break up and make it hard for the models to predict lift well," Lentink said. [In Images: Drones Take Flight in Antarctica and the Arctic]

Testing the flight models

The researchers performed their own calculations about how much lift Obi generated from his wing beats by using a device that Lentink's team developed in 2015 — an enclosed box that's equipped with force sensors so sensitive that they were able to detect vibrations produced by the lab's ventilation system, Lentink said in a statement.

They then tested three different models, plugging in the measurements of the air patterns from Obi's flights, and comparing the models' lift estimates to their own. The models produced a range of results — none of which matched the scientists' calculations.

Creating better models will be an important next step for studying animal flight, Lentink told Live Science. Video of a be-goggled Obi showed that even a slow-flying parrotlet's wing movements are more complex than scientists had anticipated. Even more variations are likely to exist across species and in animals using different flying techniques, which suggests that the current models are greatly oversimplified, the study authors wrote. Updating them will enable researchers to better understand how animals fly, and could help engineers improve flying robots — many of which mimic animals' powered flight.

"Many people look at the results in the animal flight literature for understanding how robotic wings could be designed better," Lentink said in a statement. "Now, we've shown that the equations that people have used are not as reliable as the community hoped they were. We need new studies, new methods to really inform this design process much more reliably."

Pubic Hair Grooming May Raise STI Risk

People who are sexually active and who regularly groom their pubic hair may be more likely to contract sexually transmitted infections than those who don't groom their pubic hair at all, according to a new study.

People in the study who regularly groomed their pubic hair were 80 percent more likely to report contracting a sexually transmitted infection (STI) than those who never groomed their pubic hair, the researchers found.

The study shows a link between grooming pubic hair and the increased risk of contracting sexually transmitted infections, but it does not prove that grooming one's pubic hair directly causes a person's risk of such infections to increase, said lead study author Dr. E. Charles Osterberg, an assistant professor of surgery at the University of Texas. [10 Surprising Sex Statistics]

There are two ways to explain the findings, the researchers said. It is possible that people who groom their pubic hair are more susceptible to small tears in the skin, through which bacteria and viruses that cause STIs can easily enter the body.

But it is also possible that people who regularly groom their pubic hair might simply be more sexually active than those who don't groom, and might therefore be exposed to sources of sexually transmitted infections more frequently, the researchers said.

In the study, the researchers asked 7,580 people ages 18 to 65 whether they trimmed or removed their pubic hair, and, if so, how often they did so, and what tools they used. The researchers also asked the participants how many sexual partners they'd had in their lives, and whether they had ever had a sexually transmitted infection.

In the results, 7,470 of the participants reporting having at least one sexual partner, according to the study, published today (Dec. 5) in the journal Sexually Transmitted Infections.

The researchers also found that 13 percent of the participants (943) said they'd had at least one of the following diseases: herpes, human papillomavirus (HPV), syphilis, molluscum, gonorrhea, chlamydia, HIV or pubic lice.

The link between pubic hair grooming and a higher risk of contracting sexually transmitted infections seemed to be most pronounced among people who removed all of their pubic hair at least 12 times per year and those who trimmed their pubic hair daily or weekly, the researchers found. Those individuals were up to four times more likely to contract infections than those who never groomed their pubic hair, the researchers said.

However, the people who never groomed their pubic hair were twice as likely to have lice in their pubic hair, the researchers found. This finding suggests that grooming might make it harder for lice to breed successfully, the researchers said. [The 9 Deadliest Viruses on Earth]

The study did have certain limitations. For example, the researchers were not able to determine how the timing of people's pubic hair grooming was related to the timing of when they contracted sexually transmitted infections, the researchers said.

Moreover, the researchers did not ask the participants whether they used condoms during sex, which is an important factor that lowers people's risk of contracting STIs, said Debby Herbenick, an associate professor at Indiana University Bloomington and a research fellow at the Kinsey Institute, who was not involved in the study.

Both Herbenick and the study authors noted that more research is needed to examine the link between pubic hair grooming and people's risk of STIs.

MDMA for PTSD? How Ecstasy Ingredient Works in the Brain

The active ingredient in the drug ecstasy is set to be studied in large-scale clinical trials as a treatment for people with post-traumatic stress disorder, the New York Times reported on Nov. 29.

The ingredient, MDMA, has been shown to be effective in treating people with PTSD in smaller studies, which were sponsored by the Multidisciplinary Association for Psychedelic Studies (MAPS), a nonprofit organization that advocates for medical research on psychedelic substances.

But how does MDMA (3,4-methylenedioxy-N-methylamphetamine) work in the brain? And how could its effects help those with PTSD? [6 Party Drugs That May Have Health Benefits]

MDMA has several effects on the brain that appear to make the process of talking through past traumas a more effective way of dealing with them, said Dr. Michael Mithoefer, a psychiatrist in private practice in South Carolina and a clinical researcher who has worked on earlier studies of the drug.

Currently, psychotherapy, or talk therapy, is the "definitive treatment" for people with PTSD, Mithoefer told Live Science. There are drugs approved to treat PTSD, but they only target the symptoms, he added.

Still, in a large percentage of people, psychotherapy doesn't work well to treat the condition, Mithoefer said. Researchers think that MDMA could help people with PTSD by improving how they respond when they undergo psychotherapy, he said.

The effects of the drug seem to act as a catalyst for patients, helping them talk through and process their trauma, Mithoefer said. In other words, it's not the specific actions of MDMA in the brain that appear to treat PTSD, but rather that it seems to make psychotherapy more effective, he said.

Your brain on MDMA

MDMA causes a big increase in the levels of several neurotransmitters in the brain, the most predominant of which is serotonin, Mithoefer said. Serotonin is thought to contribute to feelings of well-being and happiness.

The drug also increases levels of certain hormones, including oxytocin and prolactin, Mithoefer said.

Oxytocin, which is sometimes referred to as the "love hormone," is known to increase "affiliative behavior," Mithoefer said. Increased levels of oxytocin make people more inclined to connect with others, he said.

Oxytocin has also been shown to affect how people respond to certain facial expressions, Mithoefer said. For example, research has shown that people given oxytocin are less likely to interpret certain facial expressions as being angry or threatening, he said. This can be helpful in therapy, particularly for people with PTSD, who tend to be hypervigilant and looking for threats, Mithoefer said. An increase in oxytocin may allow someone to be more trusting. [11 Interesting Effects of Oxytocin]

The other hormone, prolactin, can cause a "post-orgasmic state," Mithoefer said. The hormone makes people feel more relaxed and increases their sense of satisfaction, he said.

Ultimately, MDMA seems to put patients in what researchers call the "optimal arousal zone," Mithoefer said. If people are "hyperaroused" and flooded with anxiety and emotions, therapy doesn't tend to be effective, he said. Similarly, when a person is "hypoaroused," effective therapy is difficult to achieve, he said.

But MDMA can give people several hours in the optimal arousal zone. "It's kind of the sweet spot where therapeutic change can happen," Mithoefer said.

The drug has also been shown to decrease activity in the amygdala, an area of the brain associated with fear, and increase activity in the prefrontal cortex, which is where information processing takes place, Mithoefer said. People with PTSD have been shown to have increased activity levels in the amygdala, he said.

Mithoefer and his colleagues have done brain-imaging studies on a small group of people with PTSD, comparing their brains before and after they took MDMA, but the results are still being analyzed, he said. The drug appears to have some effects in the brain that are opposite those linked to PTSD, he said.

Therapy in a controlled setting

People with PTSD are not likely going to feel "blissed out" when they take MDMA, Mithoefer said. In the trial that he conducted, patients did have positive experiences, but did not feel euphoric, he said.

The patients are processing the trauma that they went through, and even when they take MDMA, it is difficult and painful to do that, he said. But the drug seems to help them feel like they can go through the process without feeling overwhelmed, he said.

If the drug does eventually win approval from the FDA, researchers aren't expecting it to be something patients simply go pick up at the pharmacy, Mithoefer said. Rather, it would be given at specialized clinics under direct supervision.

For example, in Mithoefer's trial, patients underwent several preparatory psychotherapy sessions before they were given the drug. When they took MDMA, they did it under the supervision of therapists, who spent 8 hours with the patients. The patients then spent the night at the clinic, and were in touch with the therapists every day for the following week. And before their next MDMA session, the therapists met with the patients several more times.

"Like any deep therapy, [the experience] can stir things up, so it's important to have proper support to process what comes up," Mithoefer said. 

And MDMA does have negative side effects, Mithoefer said. In the short term, the drug can cause such symptoms as jaw-clenching and decreased appetite, he said. More serious side effects include increased blood pressure and pulse, he said.

MDMA increases blood pressure and pulse significantly, similar to fairly vigorous exercise, Mithoefer said. Because of this effect, people with heart disease were not included in previous studies, he said.

In addition, the researchers made sure to use pure MDMA in the studies. "On the street, you never know what you're getting," Mithoefer said. While substances sold on the street under the names "ecstasy" and "molly" may contain MDMA, they frequently also contain unknown and/or dangerous adulterants, MAPS says.

Editor's Note: This article was updated on Dec. 6 to clarify that the researchers who worked with Mithoefer were not all psychiatrists, and that Mithoefer and his colleagues are analyzing brain-imaging studies on PTSD and MDMA.

2 Million Pounds of Ready-to-Eat Chicken Recalled: Here's Why It's Risky

About 2 million pounds of ready-to-eat chicken products have been recalled because the meat could be undercooked. But what types of bacteria could be lurking in such products as undercooked poultry?

On Sunday (Dec. 4), the food manufacturing company National Steak and Poultry announced a recall of more than 1.9 million pounds of the products, which were produced from Aug. 20, 2016, through Nov. 30, 2016, according to a statement from the U.S. Department of Agriculture. The products were shipped to restaurants and fast-food chains throughout the country, and were also sold directly to consumers during a monthly public sale at the company.

The recalled products may have been undercooked, and so they have the potential to contain bacteria, the USDA said.

The bacterial pathogens most commonly linked with raw chicken are Salmonella and Campylobacter, said Benjamin Chapman, an associate professor and food safety specialist at North Carolina State University. "They're fairly common foodborne illness pathogens, but could lead to quite serious consequences" if they are consumed, Chapman told Live Science.

Both bacteria can cause diarrhea, nausea and vomiting, and in rare cases, they can cause infections that lead to such long-term health problems as arthritis, according to the Centers for Disease Control and Prevention.

Another possible bacterial contaminant of undercooked chicken is Listeria, which can grow at lower temperatures, including refrigerator temperatures, Chapman said. (Ready-to-eat meat products are typically sold refrigerated.)

Cooking any meat product to the right temperature can kill harmful bacteria, but ready-to-eat products pose a risk because consumers naturally don't always cook them, or handle them as if they were raw.

"If I'm told that I don't need to cook it, then I'm less likely to cook it to 165 degrees Fahrenheit [which kills bacteria], because it's marketed to me as you don’t actually have to," Chapman said. "If it looks like it's ready to eat, I'm likely not going to handle it, as a consumer, as stringently, as I would a non-ready to eat meat product."

So far, there have been no reports of health problems linked to the recalled products, the USDA said.

Consumers who bought the recalled products should not eat them, and instead should throw them away or return them to the place where they purchased them, the USDA said.