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Key concepts Chemistry Cooking Molecules Protein Introduction Have you ever wondered what makes pancakes so fluffy? Why do pancake recipes always tell you not to overmix the batter? The answers to these questions lie in a protein called gluten. In this activity you’ll learn about the chemical processes that make pancakes fluffy—and also why overmixing your pancake batter will result in tough, rubbery and flat pancakes. Background Pancake batter is composed of two crucial parts: dry ingredients (usually flour, sugar, baking powder, baking soda and salt) and wet ingredients (usually milk, eggs and butter)....

Dear EarthTalk: What are some of the more dangerous threats to our air quality and what can be done to eliminate them so we can all breathe more easily?—Melanie Smith, Pomfret, CT The main threats to local air quality across the United States (as well as most everywhere else) remain smog and particulate pollution, which combined or acting alone trigger millions of hospital visits and health complications for citizens every year....

Smaller fleas: What appears as a mere speck to the human eye has plenty of character when observed under a microscope. The nearly invisible Daphnia, a water flea, came to life with tufts of hair, big eyes and red “lips” when magnified 50 times. Kevin Mackenzie, manager of the University of Aberdeen’s Microscopy and Imaging Facility in Scotland, photographed this two-millimeter pond invertebrate whose wispy hair is actually a pair of antennae....

By Richard A. Lovett of Nature magazineCommon freshwater algae might hold a key to cleaning up after disasters such as Japan’s Fukushima nuclear accident, scientists said yesterday at a meeting of the American Chemical Society in Anaheim, Calif.The algae, called Closterium moniliferum, are members of the desmid order, known to microbiologists for their distinctive shapes, said Minna Krejci, a materials scientist at Northwestern University in Evanston, Illinois. But the crescent-shaped C....

The molecule best known for its part in translating genetic code into protein-assembly instructions is finding a new role in medicine. RNA, once thought to exist only in cells, is now known to travel to tissues all over the body through the blood, under the protection of tiny lipid sacs known as extracellular vesicles. The study of this extracellular RNA (exRNA) has led to a quiet revolution in biology, as scientists endeavour to understand why cells release RNA, and how the molecules might be used to improve the detection and treatment of disease (see page S6)....

Even people who claim not to be superstitious engage in rituals intended to reverse a jinx after “tempting fate.” Knocking on wood, spitting and throwing salt share a common thread: they involve avoidant actions that are directed away from the self. A new study finds that these actions help people feel better by making it harder to imagine the feared tragedy. Investigators at the University of Chicago and the National University of Singapore first engaged participants in some small talk, then turned the conversation to a topic pertaining to a specific misfortune....

Pluto’s atmosphere is even more bone-chillingly cold than one might expect 5 billion kilometres from the Sun. New research suggests that’s because of the smog that envelops the dwarf planet. “Haze is responsible for all the atmospheric cooling,” says Xi Zhang, a planetary scientist at the University of California in Santa Cruz. He and his colleagues describe the findings in the 16 November issue of Nature. When NASA’s New Horizons spacecraft flew past Pluto in July 2015, it discovered that the atmosphere was about -203 ºC, just 70 degrees above absolute zero....

GREENLAND The massive ice sheet covering Greenland is melting almost four times faster than it was in 2003, scientists have found. The gigantic hunk of ice could become a major contributor to sea-level rise in coming decades. NORTHERN IRELAND Bacteria in a soil sample from Northern Ireland effectively halt the growth of four types of antibiotic-resistant “superbugs,” including methicillin-resistant Staphylococcus aureus (MRSA). Researchers say the discovery is an important step in the battle against such resistant bacteria....

Physics has missed a long-scheduled appointment with its future—again. The latest, most sensitive searches for the particles thought to make up dark matter—the invisible stuff that may compose 85 percent of the mass in the cosmos—have found nothing. These elusive particles, called WIMPs (weakly interacting massive particles), may simply be better at hiding than physicists thought. Alternatively, they may not exist, which would mean that something is woefully amiss in the underpinnings of how we try to make sense of the universe....

After much fanfare, a minor pre-order meltdown, and what was perhaps the largest collection of Apple software updates to go out in a single week, the next iPhone arrives tomorrow. If it feels like a long time since the iPhone 4 went on sale, you’re not mistaken. The iPhone 4S, Apple’s follow-up to the iPhone 4, comes a few months later than Apple has typically released previous handsets, and it seems even longer given that leaks led to the world seeing the final design months before it was officially unveiled....

Next to the many amazing feats our brain pulls off daily, its inferior ability to juggle a few simple tasks sticks out like a sore thumb. Now research from Vanderbilt University suggests that these limits on multitasking arise from slow processing in the prefrontal cortex, the brain’s central executive. Although the area has been known to be involved in multitasking, its exact role is a matter of debate. Using functional MRI, the researchers found that when people were juggling two assignments, their prefrontal cortex appeared to deal with the tasks one by one—creating that familiar mental bottleneck—instead of processing them in parallel as do sensory and motor parts of the brain....

Many babies’ first solid food is rice cereal. It is a childhood staple, commonly recommended by pediatricians. And it is often poisoned—at least a little bit. Studies have found that many brands contain measurable amounts of inorganic arsenic, the most toxic kind. It’s not just rice: an August 2018 study by Consumer Reports tested 50 foods made for babies and toddlers, including organic and nonorganic brands such as Gerber, Earth’s Best, Beech-Nut and other popular labels, and found evidence of at least one dangerous heavy metal in every product....

Despite kids’ protests, enforcing early bedtimes may be good for their mental health. Teens who are allowed to go to bed later are more likely to suffer from depression—probably for the simple reason that they are not getting enough sleep, a recent study suggests. Columbia University scientists found that depression was 24 percent more common in teens whose parents let them go to bed at midnight or later than in kids whose moms and dads required them to hit the pillow by 10 P....

When does a monkey turn down a free treat? When it is offered by a selfish person, apparently. Given the choice between accepting goodies from helpful, neutral or unhelpful people, capuchin monkeys (Cebus apella) tend to avoid individuals who refuse aid to others, according to a study published today in Nature Communications. “Humans can build up an impression about somebody just based on what we see,” says author James Anderson, a comparative psychologist at the University of Stirling, UK....

Betting on your favorite Major League Baseball team? You might want to reconsider if it has to cross three time zones to play. A new study shows that MLB teams that travel such distances to play a game could have up to a 60 percent chance of losing. The reason: players’ body clocks are out of whack, giving their opponents an advantage, according to W. Christopher Winter, a neurologist at the Martha Jefferson Sleep Medicine Center in Charlottesville, Va....

No matter what they tried, the staff at Queen Elizabeth Hospital Birmingham in England could not quell an outbreak of a multidrug-resistant pathogen. After an incredible 40 weeks infection control specialists worried that if they could not get on top of the situation, Acinetobacter baumannii could become a permanent hospital resident lying in wait for any patient, the way multidrug-resistant Clostridium difficile does in many hospitals. Another 40 weeks passed before the staff broke the stranglehold, declaring the hospital free of a pathogen considered among the most difficult to control....

Introverts have been having their moment. Ever since the best seller Quiet came out in 2012, the reserved among us have been stepping up and speaking out, eager to take power back from the endlessly chattering extroverts. The book, written by former lawyer and professed introvert Susan Cain, argues that our society coaxes introverts into unnecessarily behaving like extroverts. As a result, she contends, we miss out on introverts’ unsung virtues, and quiet people should not be forced to endure gregarious gaggles of people that actually exhaust them....

Science fiction often envisions worlds populated by humanoid robots. In reality, insects, reptiles and nonhuman animals often serve as a more practical template for automatons. The more legs a robot has, the more easily it can navigate tough terrain. Likewise, claws are less challenging to emulate than primate-esque hands, and, as a team of researchers reported recently, tails are an incredibly versatile stabilizing mechanism. The back end of snakes, ants or even grasshoppers has served as such an inspiration to some roboticists....

The military and intelligence communities may soon turn a blinder eye toward some climate change-related threats, indicated by President-Elect Donald Trump’s recent choices of climate-change skeptics for national security jobs, along with his own dismissive comments. But though experts say Trump and his team could roll back some recent initiatives, the momentum of bureaucracy, along with a military need to take the long view, mean climate-related plans are unlikely to be abandoned entirely....

Over the swaying oceans and in the sun-soaked skies, there is more than enough energy to sail or fly around the world on light energy alone. Such endeavors are currently tricky and costly, but some developers are pushing the limits of technology as well as their own endurance to break air and water records. With much of the planet mapped, photographed and digitized, these sailors and pilots believe the next frontiers lie in technology, in going farther, faster and cheaper and using less to do so....