Culprit of Deadly Tibet Avalanche: Climate Change

An avalanche of ice that killed nine in western Tibet may be a sign that climate change has come to the region, a new study finds.

The avalanche at the Aru glacier in July 2016 was a massive event that spilled ice and rock 98 feet (30 meters) thick over an area of 4 square miles (10 square kilometers). Nine nomadic herders and many of their animals died during the 5-minute cataclysm. It was the second-biggest glacial avalanche ever recorded, and initially mystified scientists.

"This is new territory scientifically," Andreas Kääb, a glaciologist at the University of Oslo, said in a statement in September. "It is unknown why an entire glacier tongue would shear off like this.

Now, an international group of scientists thinks they know the reason: Meltwater at the base of the glacier must have hastened the slide of the debris.

"Given the rate at which the event occurred and the area covered, I think it could only happen in the presence of meltwater," Lonnie Thompson, a professor of Earth sciences at The Ohio State University, said in a statement.

Thompson and his colleagues from the university's Byrd Polar and Climate Research Center worked with scientists from the Chinese Academy of Sciences to measure the icefall and recreate it with a computer model. They based the model on satellite and global position system (GPS) data, allowing for a precise understanding of how much debris fell.

The stimulations could only recreate the catastrophic collapse if meltwater was present. Liquid water at the base of a glacier speeds its advance by reducing friction, as is frequently seen in Greenland. Meltwater may also bring heat to the interior of the glacier, warming it from the inside, according to 2013 research on Greenland's glaciers.

In western Tibet, the origin of the possible meltwater is unknown, Thompson said in the statement. However, the region is undoubtedly heating up.

"[G]iven that the average temperature at the nearest weather station has risen by about 1.5 degrees Celsius (2.7 degrees Fahrenheit) over the last 50 years, it makes sense that snow and ice are melting and the resulting water is seeping down beneath the glacier," Thompson said.

That's particularly alarming because western Tibet's glaciers have so far been stable in the face of warming temperatures, according to the researchers. In southern and eastern Tibet, the glaciers have been melting much more rapidly. Above-average snowfall in western Tibet has even expanded some glaciers, according to study author Lide Tian, a glaciologist at the Institute of Tibetan Plateau Research at the Chinese Academy of Sciences. Paradoxically, Tian said in a statement, that extra snowfall may have created more meltwater and made the devastating avalanche more likely.

A second avalanche hit just a few kilometers away in September 2016. No one was harmed in that icefall, but Kääb and his colleagues said that the two collapses, so close in time and space, were unprecedented.

ChooseMyPlate: Tools & Resources for Healthier Diet

The U.S. government's Dietary Guidelines for Americans offers recommendations on food and nutrition. The guidelines focus on ways to improve what Americans eat and to reduce certain health conditions that can be caused by poor diet.

The current guidelines, called the 2015-2020 Dietary Guidelines for Americans, were announced on January 7, 2016, and were unveiled along with new teaching visuals and a website called ChooseMyPlate.gov, which has tools and resources to help Americans implement the new guidelines. An advisory committee of researchers and scientists in the fields of nutrition, health and medicine had met for about a year to review and update the 2010 Dietary Guidelines, according to the American Medical Association.

"Protecting the health of the American public includes empowering them with the tools they need to make healthy choices in their daily lives," Secretary of Health and Human Services Sylvia M. Burwell said in a press release. "By focusing on small shifts in what we eat and drink, eating healthy becomes more manageable. The Dietary Guidelines provide science-based recommendations on food and nutrition so people can make decisions that may help keep their weight under control, and prevent chronic conditions, like Type 2 diabetes, hypertension, and heart disease."

Overall guidelines

The big difference between the old dietary guidelines and the new ones are that instead of focusing on food groups, these guidelines focus on healthy eating patterns overall. 

According to the U.S. Department of Agriculture, five main tenets sum up the new edition:

1. Follow a healthy eating pattern throughout life. 
2. Focus on eating a variety, nutrient-dense foods at an appropriate amount.
3. Reduce sodium intake and limit calories from added sugars and saturated fats.
4. Shift to healthier food and beverage choices.
5. Support healthy eating patterns for everyone.

These five guidelines are further broken down into what Americans should eat to stay healthy:

• Consume variety of vegetables, including dark green, red and orange, legumes (beans and peas), starchy and other vegetables.
• Eat fruits, especially whole fruits.
• Eat grains, with at least half being whole grains.
• Include fat-free or low-fat dairy into a healthy diet, including milk, yogurt, cheese, and/or fortified soy beverages.
• Consume a variety of protein foods, including seafood, lean meats and poultry, eggs, legumes (beans and peas), soy products, and nuts and seeds.
• Include oils from plants such as canola, corn, olive, peanut, safflower, soybean and sunflower. 

It also recommends some limits:

• A moderate caffeine habit is okay. The guidelines recommend drinking up to three to five 8-ounce cups of coffee per day or up to 400 milligrams per day of caffeine. (However, these guidelines are for those who already consume caffeine. If you aren't a caffeine drinker, the guidelines do not recommend starting.) 
• Consume less than 10 percent of calories per day from added sugars. 
• Consume less than 10 percent of calories per day from saturated fats. (The guidelines do not encourage a low-fat diet. According to the guidelines, 35 percent of total calories per day should be from fat.)
• Consume less than 2,300 milligrams (mg) per day of sodium for people over the age of 14 years and less for those younger. 

The MyPlate Daily Checklist

Another change is the teaching visuals. Gone is the food pyramid; the new visual is a plate and cup that is divided into serving sizes. Also, the Daily Food Plan's name has changed to The MyPlate Daily Checklist. 

Instead of general estimates of serving sizes, the new checklist offers what to eat and how much to eat within your calorie allowance, according to your age, height, sex, weight and physical activity level. The MyPlate Daily Checklist is fully customizable by imputing personal information into the MyPlate Checklist Calculator.

Once the calculator runs the information, it comes up with a suggestion of how many calories the user needs to eat to maintain or reach a healthy weight. It also offers an eating and exercise plan that can be printed out and used to track progress. 

The ChooseMyPlate website has many other helpful features, such as a BMI calculator, daily eating checklist, preschooler growth charts, a pregnancy weight gain calculator and a SuperTracker. The SuperTracker helps users analyze, plan and track their diet and physical activity. It also offers virtual coaching, goal setting and journaling options.

Does Marijuana Use Affect a Person's Vision

Regular marijuana use may affect how well certain cells in the eye's retina function, a small new study finds.

But some experts say that the evidence presented in the study isn't strong enough to support the link between these two factors.

The cells that the researchers focused on in the study, called retinal ganglion cells, are located near the inner surface of the eye's retina. These cells collect visual information and transmit it to the brain.

The study included 52 people who had used marijuana at least 7 times per week during the previous month and 24 people who had never used marijuana. The people in both groups were between 18 and 35 years old. The researchers verified the marijuana use by testing the people's urine for THC, marijuana's main psychoactive ingredient.

The researchers tested the participants' vision and found that their eyesight was relatively good, and that no one in the study group reported having any visual problems from using marijuana such as blurred vision, according to the study, which was published today (Dec. 8) in the journal JAMA Ophthalmology.

To study how well the participants' retinal ganglion cells worked, the researchers used a method called pattern electroretinography, which provides information about how well those cells function, as well as how fast they transmit visual information from the retina to the brain.

The test revealed that, compared to the people who didn't use marijuana, those who did use the drug had a slight delay in how long it took for information to be transmitted from the retina to the brain, according to the study.

It's not clear whether this potential effect of marijuana is permanent, or would stop when a person stops using the drug, said study co-author Dr. Vincent Laprévote, a psychiatrist at Pôle Hospitalo-Universitaire de Psychiatrie du Grand Nancy in France.

But some experts argue that the study had significant limitations, and because of this, it's unclear whether or not there is an actual link between marijuana use and these effects.

More research is needed to determine whether marijuana use really is linked to changes in the functioning of those cells, said Dr. Christopher J. Lyons, an ophthalmologist at the University of British Columbia, who was not involved in the study. [Marijuana Could Treat These 5 Conditions]

Lyons noted that although the electroretinography results suggested a difference between marijuana users and nonusers, the delay didn't seem to translate into actual problems with the users' vision.

Indeed, the marijuana users in the study did not experience any actual visual symptoms or changes in the quality of their vision, Lyons told Live Science.

In an editorial that was published in the same journal as the study, Lyons and Dr. Anthony Robson, an ophthalmologist at the University College London who was also not involved in the study, noted that the researchers examined the people's marijuana use through urine tests, which are not as accurate as blood tests.

In addition, there are many other factors such as tobacco use, diet and lifestyle that might affect the functioning of a person's retinal cells, and these factors could have affected the results of the study, Lyons and Robson wrote.

Moreover, while the study authors said that the abnormalities that they found in the study that involved the functioning of the marijuana users' retinal ganglion cells might explain why some marijuana users experience altered vision, they did not present any evidence in the study to support this statement.

Conjoined Twin Girls Successfully Separated

Conjoined twin girls who shared much of their lower body were successfully separated after a surgery that took 17 hours, their doctors said.

The 2-year-old girls, Erika and Eva Sandoval, were born joined from the lower chest downwards, and shared a liver, a bladder and a leg, according to a statement from Lucile Packard Children's Hospital Stanford in Palo Alto, California, where the surgery was performed. They each had their own heart, lungs and stomach, but had some connections within their digestive system, the statement said.

The marathon surgery to separate the twins required a team of about 50 doctors, nurses and operating staff, and was finished in the early morning of Dec. 7. The girls are in stable condition, and are expected to stay about two weeks in the intensive care unit, and an additional two weeks in the hospital before going home, the statement said. 

"It's amazing how strong these girls are and it's amazing what their team performed," Aida Sandoval, the twins’ mother, said in a statement. "Seeing them now in the ICU, you look at them and think, 'You're missing your other half,' but we know that this is the right path for them: to be independent, have the chance to succeed and explore on their own everything the world has to offer."

The surgery required extensive preparation, including CT and MRI scans, which were used to create 3D models of the girls' pelvic bones and blood vessels. Even with this preparation, the doctors still encountered surprises during surgery, said Dr. Gary Hartman, who led the surgery. For example, they found that the large intestine, which appeared to belong to Eva, had some blood supply from Erika, and this required additional testing to clarify, Hartman said.

Now that the girls are separated, they are each missing about a third of their abdomen, and they each have one kidney and one leg, the statement said. The surgeons needed to remove the third leg, and the skin and muscles in this leg were used to help close Erika's abdominal wall. The third leg had abnormal anatomy, and so neither girl would have been able to walk with it, the statement said.

Going forward, the team will assess whether the girls need any further reconstructive surgeries. "We set them up so that if everything heals well, they may not need any further surgery," Hartman said. "The results are as good as we could have asked for."

Conjoined twins are rare and occur in about one out of every 200,000 live births, according to the University of Maryland Medical Center. Among conjoined twins that are born alive, about half do not survive for more than 24 hours.

Surgeries to separate conjoined twins are performed about five times a year in the United States, according to Packard Children's. In October, surgeons in New York successfully separated twin boys who were joined at the head.

This is the third set of conjoined twins separated at Packard Children's, with the other surgeries performed in 2007 and 2011.