【推荐1】Jealousy is such a powerful emotion that at least one study has characterized it as the third leading cause of non-accidental homicide(杀人) in all cultures. In a recently published study, researchers experimented with dogs to see whether they, like humans, have the nature of jealousy.

In an experiment, the authors took 36 dogs---along with their owners---and observed the dogs’ behavior as their masters interacted with three non-living objects. One object was a children’s book, which they read aloud; another object was a plastic pumpkin lantern; and the third was a mechanical stuffed dog that gave out a bark when the owner pressed a button.

Former studies concluded that babies were probably capable of jealousy. In the experiment, their mothers showed attention to a life-like doll instead of their child, and other objects. The babies were reportedly more likely to respond with “negative” behavior if their mother turned to pay her attention to the doll.

In the dog experiment, authors instructed the dog owners to push the bark button on the stuffed dog’s head, and then speak to it sweetly, while ignoring their own dog. After that, they showed attention to the pumpkin lantern, and read the children’s book, while also ignoring their dog.

It is interesting to see the dogs were far more likely to act aggressively when their owners spoke to the stuffed dog than when they paid attention to the other objects. One-fourth of the dogs snapped at the stuffed dog, while only one dog snapped at the lantern or the book. The dogs were also more likely to push or touch their owners as they interacted with the mechanical dogs, and tried to get in between the owner and the stuffed dog more frequently than the other objects.

“One possibility is that jealousy developed in species of many young relying on the parents, the young compete for parental resources such as food, attention, care, and affection,” the authors wrote.

【推荐2】Dyslexia (失读症) is a reading and writing disability characterized by difficulties in reading and spelling, and for some readers to understand what they have read. Experts say dyslexia affects about five to ten percent of the population of the United States. Researchers have long known that people with dyslexia write or read words and letters backwards in the wrong order.

But a new study shows that people with dyslexia may have trouble redirecting (重新传入) their attention between senses, from seeing something to hearing something. Vanessa Harrar of Britain's University of Oxford led the study. She reported the findings in the journal Current Biology. The study suggests that dyslexic people may have trouble moving quickly from what they read to what they hear. Doctor Harrar calls this a sluggish shifting of attention across the senses.

''So, if you are trying to read something and then trying to listen to somebody who's reading aloud and you're trying to follow along with what they are reading, they have to switch their attention from hearing what they are saying to looking at the piece of paper and back again. '' said Harrar.

She found that people with dyslexia were just as fast as the others when they saw only a picture or heard only a sound. But the dyslexics had a slower reaction time when they heard a sound and saw a picture at the same time.

Doctor Harrar feels like playing action video games could help dyslexic people shift from seeing to hearing more quickly. She adds that images in video games force the eyes to move and focus quickly.

''Video game types of things pop out of here and there, they move your eyes around the screen quickly in response to things quite quickly, and the more you play a video game the faster you get that kind of thing. So the video game is really training the attention system to move quickly, '' said Harrar.

The study also shows that dyslexic people have the most difficulty going between what they saw and what they heard, this may have an effect on how dyslexic children are taught how to read. When children learn the alphabet, they usually see the letter first and then hear the sound, or they see and hear the letter at the same time. The study shows that dyslexics might learn more quickly if they hear the sound of a letter or word first before seeing it.

【推荐3】The Maya city of Tikal is famous for its amazing palaces and temples. But something far more ordinary kept Tikal functioning: its water-purifying(净化) system, the earliest known of its kind.

Researchers recently discovered a volcanic mineral that traps microbes(微生物) and heavy metals in Tikal's largest reservoir(水库). Because the material is not found nearby, the finding suggests the presence of a man-made water-purifying device.

The finding denies the long-standing idea that the ancient worlds technological achievements belonged to the Eastern world, like Egypt, and China. The leading scientist of this research, Kenneth Tankersley says, “When talking about purifying water, the Maya were thousands of years ahead.”

Located in the forests of Central America, Tikal, is thought to have been home to more than 45,000 people. They had to struggle against a dry season lasting from November through April. Storing water in reservoirs was a solution, but that water had to be fit to drink, said Kenneth, “Keeping water clean was of great importance.”

A few years ago, the researchers were surprised to find that the largest reservoir, Corriental, had significantly fewer harmful chemicals than the others. “The water quality at Corriental was much higher.”

Somehow the Maya must have been purifying Corriental’s water, the team assumed. “The Maya used gardens as their bathrooms.” Kenneth said, “The water coming into the reservoir would not have been very clean.”

At the bottom of Corriental, scientists found four separate layers(层), each a few centimeters thick, of millimeter-scale “zeolites(沸石)”. This type of volcanic mineral can purify water and is still in widespread use today, Kenneth says, “Just about everything we drink, from bottled water to wine, runs through a zeolite purifying device.”

The Maya wouldn’t have known about the zeolite in rock, but they would have recognized the purifying effects, the researchers suggest. A zeolite-rich rock formation about 30 kilometers northeast of Tikal is the likely source of the material in Corriental reservoir, the team said last month in Scientific Reports. Water at this site “was clear and tasted good.”