Rats

Are you ready for this jelly? Using rat heart cells and silicone, engineers at Caltech and Harvard have built a tiny, swimming, artificial jellyfish. The centimeter-wide creation moves by using muscles in its soft body to pump water, just as its living peers do. And since real jellyfish, with their long tentacles, were once named after Medusa, the snake-haired monster of Greek myth, the scientists have dubbed their nonliving critter Medusoid. Rather than try to mimic the jellyfish wholesale, the researchers decided to identify some of the factors  that make the jellyfish a successful swimmer - shape, stroke cycle, properly organized muscle fibers, elastic recoil - and built their jelly according to those principles.

From the moment Azealia Banks swagger-sashayed onstage before a capacity crowd at the Fonda Theatre on Saturday, she radiated old-fashioned star magnetism and immediately showed why she'd been tagged one of hip-hop's brightest new stars - even though she'd distanced herself from the genre, saying she'd "rather be a dance artist. " Dressed in a sheer bodysuit with strategically placed strips of material and sporting her signature thick mane of mermaid-style hair, the 21-year-old unleashed a rat-a-tat-tat stream of perfectly enunciated words - creating that most foundational of relationships between a rapper and her fans.

Armed with a new county report citing the health dangers of feces, urine and hypodermic needles recently found on Los Angeles' skid row, city officials could resume controversial cleanup sweeps of the downtown area's streets and sidewalks. The Los Angeles County Department of Public Health inspected a nine-block area and discovered human waste, injection needles, condoms and a rat infestation in violation of county and state health codes. City officials say they have cleaned up the waste and debris cited by inspectors last month.

Paralyzed rats learned to walk, run and spring deftly over obstacles after they were put on a physical training regimen that included electrical and chemical stimulation of their broken spinal columns and a “robotic postural interface,” a new study reveals. The study, published Thursday in Science , suggests that for humans with spinal cord injury, the trick to regaining lost movement may lie not in regeneration of the severed spinal cord, but in inducing the brain and spinal cord to forge wholly new paths toward each other.

Rats fed fructose-laced drinking water for six weeks performed more slowly in a maze-navigating task, UCLA researchers have found. (Read this L.A. Times opinion article .) They think the effect is due to changes in the way the brain responds to insulin as a result of exposure to fructose. “Our study shows that a high fructose diet harms the brain as well as the body,” study senior author and UCLA professor Fernando Gomez-Pinilla said in a release about the finding, which was published in the Journal of Physiology (postdoc Rahul Agrawal was first author)

The comparisons will be inevitable between the Starz drama "Magic City" and AMC's critical darling "Mad Men. " So let's get a few of them out of the way. Each is populated with drop-dead-gorgeous dames and rakishly handsome fellas. Both take place in the glamorous Rat Pack era — late '50s, early '60s — when stylish folks drove cars the size of luxury liners and ordered highballs for lunch. They name-check real historical figures like the Kennedys and Frank Sinatra, and social upheaval bubbles in the background.

Singer and actress Kaye Stevens, 79, who performed with the Rat Pack and frequently appeared on Johnny Carson's late-night talk show, died Wednesday at Villages Hospital north of Orlando, Fla. She had breast cancer and blood clots, said her friend Gerry Schweitzer. During the Vietnam War era, Stevens also performed for American soldiers in the war zone with Bob Hope's USO tour. Rat Pack members she shared the stage with included Frank Sinatra, Dean Martin and Sammy Davis Jr. She also sang solo at such venues as Caesars Palace in Las Vegas and the Plaza Hotel in New York City.

In the den of Darryl Roth's Corona home, cartoon ogres cover the walls, staring back at him with salivating tongues, bloodshot eyes, jagged claws and gnashing teeth. To Roth, the images represent rebellion, a gloriously grotesque imagination — and his father. "I look around and I swear, it's like he's still alive. He's still here," Roth said. He's the youngest son of iconic hot rod artist Ed "Big Daddy" Roth, and this year marked the 10th anniversary of his father's passing. "Even now," said the son, "I'm blown away by him. " Between the late 1950s and the mid-1960s, Ed Roth was what famed journalist Tom Wolfe described as the Salvador Dali of the hot rod world.

For those lucky enough to have the first signs of a stroke recognized by friends or family, things often get very quiet very quickly as 911 calls are made, gurneys are wheeled in and tests are conducted. University of California Irvine neuroscientist Ron D. Frostig says that if rats are any guide to human health (and they often are the starting point for new treatments), stroke victims might do a lot better with a quick dose of stimulation instead. At his lab, Frostig had long noticed that a rich sensory environment appeared to make rats not only happier but much healthier.

Forget about rock 'n' roll: When rats are administered the highly addictive stimulant methamphetamine and allowed to engage in sexual behavior while high, all they want is more of both. That's the raw finding of a study published Tuesday by the Journal of Neuroscience. It's important because many who use methamphetamine report that it enhances their sexual experience. But because it also reduces their inhibitions , those abusers are more likely to engage in risky sexual behavior , including unprotected sex and anal intercourse.