TIME animals

Scientists Just Found Out How Chameleons Change Color

What color is #ThisChameleon?

Scientists may have finally unlocked the mystery behind chameleons’ unique ability to change color.

The explanation is that the reptile’s skin is made up of tiny mirror-like crystals, contained within reflective pigment cells called iridophores. That’s according to a new study published in the journal Nature Communications.

When the chameleon gets excited, or anticipates danger, the iridophores expand or contract to enable the crystals to reflect different levels of light, thereby changing its skin color.

The researchers used a combination of microscopy, high-resolution videography and color-based numerical modeling to arrive at this discovery.

“When the skin is in the relaxed state, the nanocrystals in the iridophore cells are very close to each other — hence, the cells specifically reflect short wavelengths, such as blue,” Michel Milinkovitch, a professor of genetics and evolution at the University of Geneva in Switzerland and the lead author of the study, told Live Science.

Milinkovitch further explained that, when excited, the nanocrystals spread further apart to reflect longer wavelengths like yellow, red and orange, which combine with blue to produce different hues.

If any of those hues is white, gold, black, or blue, we might just have chameleons breaking the Internet soon.

Read next: The Weird Reason Humans Shake Hands as a Greeting

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TIME Heart Disease

Depression and Stress Could Be ‘Perfect Storm’ for Heart Disease Patients

The combination of depression and stress may increase the chance of a patient dying of heart disease

Intense stress and depression in people with coronary heart disease creates a “perfect storm” that can increase the risk of death, according to a new study in the journal Circulation: Cardiovascular Quality and Outcomes.

Overall, patients with both conditions are nearly 50% more likely to die or experience a heart attack as a result of heart disease than those with low stress or depression. The results were most apparent in the first two and a half years after observation began.

“The increase in risk accompanying high stress and high depressive symptoms was robust and consistent across demographics, medical history, medication use and health-risk behaviors,” said lead study author Carmela Alcántara, a researcher at Columbia University Medical Center.

The study, which looked at nearly 4,500 adults, expanded on previous research that found that both depression and stress can independently increase the risk of heart disease. The study suggested that some previous research may have misattributed the cause of heart-disease death to stress or depression independently. In reality, the study suggests, the interaction between stress and depression may have led to death rather than either independent factor.

The study traced participants for an average of nearly six years and asked patients to self-report symptoms of depression and stress. Overall, 6.1% of study participants had both high stress and intense symptoms of depression. Only 5.6% of the total sample had high stress alone, and 7.7% had intense symptoms of depression alone.

Researchers said the results suggest that doctors may want to consider additional methods to treat heart disease that include interventions to treat stress and depression.

TIME Mental Health/Psychology

This Is Where Young People Are More Likely to Commit Suicide

Gun ownership may be affecting youth suicide rates, study finds

Young people who live in rural areas kill themselves at twice the rate as youth who live in cities, according to a new study in the journal JAMA Pediatrics.

There aren’t clear-cut explanations for suicide, but geographical differences seem to play a role, the researchers found. People who live in rural areas have less access to mental-health services, more stigma surrounding help-seeking and freer access to guns than their urban counterparts.

The study, which looked at data from more than 66,000 young people ages 10 to 24 who died by suicide in the U.S., found that the gap between the urban and rural suicide rates grew significantly from 1996 to 2010.

About half of the people in the sample used a firearm to end their lives, followed by a third who died by suffocation. In rural communities, young people were more likely to use a gun — no coincidence, according to the study authors, since suicide rates in urban communities dropped alongside a decline in urban gun ownership.

Geography may partially explain the difference between rural and urban suicide rates, according to the study. Mental-health services can be harder to access in rural areas; more than half of rural communities in the U.S. don’t have a local mental-health worker like a psychiatrist or psychologist. Those who do have access to mental-health resources may be reluctant to use them because of stigma, and self-reliance is often seen as virtue in rural communities, the study says. Remote locations also mean smaller social networks and fewer people to rely on providing help. High unemployment and flailing economies have also depressed small towns.

MORE: Suicide Rate for Young Women Rises in U.S.

An editorial accompanying the study by Frederick Rivara, M.D., professor of pediatrics at the University of Washington, acknowledges that political forces make tougher gun laws unlikely. He argues instead for storing weapons safely. Various safe storage methods, including trigger locks and gun safes, can reduce the risk of suicide by as much as 70%, Rivara writes.

“The problem of suicide and the issue of firearms are very complex public health concerns,” writes Rivara. “But, in the United States, they also appear to be integrally linked and demand our attention.”

TIME Research

Low Testosterone Levels Are Not the Cause of Less Sex but the Result of It

So says a new study conducted on a large group of older men in Australia

It’s normally thought that lower testosterone levels in older men lead to less appetite for sex. However, an intriguing new study from Australia finds that a decline in testosterone levels appears to be the result of a lower libido. That’s according to a report in Science Daily.

“In older men, decreased sexual activity and desire may be a cause, not an effect, of low circulating testosterone level,” concluded lead study author Benjumin Hsu, from the University of Sydney’s School of Public Health.

The research followed men who took part in the Concord Health and Aging in Men Project — a study of 1,705 Sydney men ages 70 or over, described by organizers as “one of the world’s largest and most comprehensive study of the health of older men ever conducted anywhere in the world.”

During a two-year period, scientists found that baseline serum testosterone levels in men did not predict a decline in sexual activity or libido. By contrast, a decline in testosterone was strongly related to less sex and less desire.

Researchers behind the new report stress that it remains unclear what other age-related factors may be behind the reduction in testosterone levels.

[Science Daily]

TIME Research

This New Drug Turns ‘Bad’ White Fat Into ‘Good’ Brown Fat

GC-1 could have the potential to treat obesity and metabolic disease

Scientists claim they have found an experimental drug that turns “bad” white fat cells into “good” brown ones.

Known as GC-1, the drug speeds up metabolism, or the burning off of fat cells, reports Science Daily. Researchers found it caused weight loss in fat mice.

“GC-1 dramatically increases the metabolic rate, essentially converting white fat, which stores excess calories and is associated with obesity and metabolic disease, into a fat like calorie-burning brown fat,” said study author Kevin Phillips of the Houston Methodist Research Institute.

Until recently, scientists thought only animals and human infants had these energy-burning “good” brown-fat cells.

“It is now clear that human adults do have brown fat, but appear to lose its calorie-burning activity over time,” Phillips added.

He calls white fat a “metabolic villain” when you have too much of it, whereas people with more brown fat have a reduced risk of obesity and diabetes.

GC-1 works by activating receptors for the thyroid hormone, which help regulate how your body turns food into energy.

Phillips’ team tested the drug on hundreds of mice who were genetically obese or who had diet-induced obesity. They found genetically obese mice lost weight and nearly 50% of their fat mass in two weeks. Diet-induced obese mice also showed improvements.

The drug was also tested on white fat cells grown in a lab, and researchers say they found evidence that the drug turned white fat into the brown variety.

Phillips hopes the drug, which has not yet been tested on humans, has the potential to treat obesity and metabolic disease.

The results of the study will be presented at the Endocrine Society’s 97th annual meeting in San Diego on Friday.

[Science Daily]

TIME Research

Suicide Rate for Young Women Rises in U.S.

But young men are still three times more likely to commit suicide than women

The suicide rate among young women has risen in the U.S., leading to an overall uptick in cases, despite a falling number for young men taking their own lives.

A weekly report issued by the Centers for Disease Control and Prevention (CDC) analyzed data from 1994 to 2012 and found the suicide rate of women ages 10 to 24 years old rose from 2.7 to 3.2 cases per 100,000. Additionally, the report says there has been a significant climb of suicides since 2007 when measured across all genders.

However, young men are still three times more likely to commit suicide than women. The rate fell from 15.7 to 11.9 per 100,000 in 1994. Furthermore, since 2007 the suicide rate also increased after a significant decrease between 1994 and 2007.

The CDC reported that 17% of high school students have seriously considered suicide, and 8% have attempted to kill themselves more than once.

TIME Innovation

Five Best Ideas of the Day: March 5

The Aspen Institute is an educational and policy studies organization based in Washington, D.C.

1. 2.7 million American children have a parent in prison. We can learn from South Africa’s belief in a “right to childhood.”

By Lauren Lee White at the USC Center on Public Diplomacy

2. Imagine handling an ancient artifact or typing on a virtual keyboard. Holograms you can feel are here.

By Anthony Cuthbertson in International Business Times

3. One school district is bringing down the silos between art, computer science and technology education to give kids skills for the future.

By Todd Keruskin in EdSurge

4. They cost less and give patients a better experience. It’s time to drop the barriers on nurse practitioners.

By Matthew Yglesias in Vox

5. To keep their labs supplied with cheap labor, universities are churning out PhDs. But there’s no work for them after graduation.

By Brenda Iasevoli in The Hechinger Report

The Aspen Institute is an educational and policy studies organization based in Washington, D.C.

TIME Ideas hosts the world's leading voices, providing commentary and expertise on the most compelling events in news, society, and culture. We welcome outside contributions. To submit a piece, email ideas@time.com.

TIME Research

One-Third of the World’s Population Suffers From Untreated Tooth Decay

Dental check-up
Echo—Cultura RF/Getty Images

Untreated tooth decay can engender cavities, infections, abscesses, oral pain and diseases

Untreated tooth decay is a problem for more than 2.4 billion people worldwide, with some 190 million new cases forecasted each year, finds a new study in the Journal of Dental Research.

Experts say this is a worryingly large number for a problem that is both well known and highly preventable.

“It is alarming to see prevention and treatment of tooth decay has been neglected at this level,” says the study’s lead researcher, Dr. Wagner Marcenes.

Scientists conducted a global survey of 378 studies looking at nearly 5 million people from 1990 to 2010. The results showed that 2.4 billion people suffer from untreated tooth decay in their permanent teeth, with 621 million children facing untreated decay in their early, temporary teeth.

Untreated tooth decay can engender cavities, infections, abscesses, oral pain and diseases. Ignored, it can impede a child’s growth and cause work absenteeism and unproductivity in adults. Dental decay is an effect of mouth acids dissolving the exterior teeth layers.

Scientists impute dental decay to high consumption of sugar, cautioning the public that children are not the only offenders.

“What is clear is that this is a major public health problem,” added global oral-health expert Professor David Williams of the Queen Mary University of London.

[BBC]

TIME Research

New Hormone Discovered That Curbs Weight Gain, Diabetes Just Like Exercise

“This represents a major advance in the identification of new treatments for age-related diseases such as diabetes”

Scientists have discovered a new hormone that mimics the health benefits of exercise by normalizing the metabolism and slowing the weight gain caused by fatty diets.

Appearing in the scientific journal Cell Metabolism on Tuesday, the study found the newly discovered MOTS-c hormone increases insulin sensitivity, allowing the body to more effectively process glucose sugars, according to a press release from the University of Southern California.

Insulin is a hormone that is used to move glucose sugars from food into the blood stream; resistance occurs when levels are high for a long period of time — commonly from a poor diet — which increases the body’s tolerance to the hormone and can lead to type 2 diabetes.

The new MOTS-c hormone targets muscle tissue and reverses age-dependent and diet-related insulin resistance.

“This represents a major advance in the identification of new treatments for age-related diseases such as diabetes,” said Dr. Pinchas Cohen, senior author of the study.

Researchers injected the new hormone into lab mice eating high-fat foods that usually lead them to become obese. The injection suppressed the weight gain and also reversed the insulin resistance caused by their diet.

While tests were only administered on mice, the necessary mechanisms are present in all mammals, humans included.

Read next: 5 Non-Diet Factors That Can Affect Your Weight

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TIME Food & Drink

This Is Why Indian Food Is So Delicious

Holger Leue—Lonely Planet Images/Getty Images Thali dinner at Amrit Rao Peshwa Palace

It's the lack of overlapping flavors, scientists say

Indian food is lauded for its curries, mouth-burning spices and complex flavor pairings. With its use of cardamom, cayenne, tamarind and other pungent ingredients, the resulting taste combinations are unlike anything found elsewhere around the world. But scientists in India have now discovered exactly why Indian food is so good — it’s the fewer number of overlapping flavors in ingredients.

Researchers at the Indian Institute for Technology examined how frequently overlapping flavor compounds factored into a dish’s ingredients. They reviewed thousands of recipes on TarlaDalal.com, scrutinizing the subtle molecular-level differences that distinguish the cuisine, reports the Washington Post.

“We found that average flavor sharing in Indian cuisine was significantly lesser than expected,” researchers wrote.

In Western cuisines, ingredients are usually paired together for their similar flavors. However, an average Indian dish includes at least seven ingredients, most of which do not contain overlapping flavors. Cayenne, green bell pepper, coriander and garam masala are usually paired with ingredients that have no chemical overlap, but each ingredient brings a unique component when incorporated into the final meal. This creates knockout dishes for a cuisine that uses approximately 200 of the estimated 381 ingredients known in the world.

Read more at the Washington Post

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