Earth is becoming ‘Planet Plastic’

Hasil carian imej untuk earth is becoming a plastic

US scientists have calculated the total amount of plastic ever made and put the number at 8.3 billion tonnes.

It is an astonishing mass of material that has essentially been created only in the last 65 years or so.

The 8.3 billion tonnes is as heavy as 25,000 Empire State Buildings in New York, or a billion elephants.

The great issue is that plastic items, like packaging, tend to be used for very short periods before being discarded.

More than 70% of the total production is now in waste streams, sent largely to landfill – although too much of it just litters the wider environment, including the oceans.

“We are rapidly heading towards ‘Planet Plastic’, and if we don’t want to live on that kind of world then we may have to rethink how we use some materials, in particular plastic,” Dr Roland Geyer told BBC News.

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Giant mud balls roamed the early solar system

Ceres

The earliest asteroids were probably made of mud, not rock.

Radioactive heat in the early solar system could have melted globs of dust and ice before they had a chance to turn to rock, a new simulation published July 14 in Science Advances shows. The results could solve several puzzles about the composition of meteorites found on Earth and may explain why asteroids are different from comets.

Most knowledge about the first solid bodies in the solar system comes from meteorites called carbonaceous chondrites, thought to be chunks of the first asteroids. Their chemical compositions are almost identical to the sun’s — if you took all the hydrogen and helium out of the sun, you’d get the mineral ratios found in these bits of rock.

That similarity suggests the first asteroids formed directly from the disk of gas and dust that preceded the planets. The composition also suggests that these rocks formed in the presence of water and at relatively low temperatures, around 150° Celsius.

It’s hard to explain all those features at once. If the original asteroids were bigger than about 20 kilometers across — and there’s no reason to think they weren’t — decaying radioactive elements inside them would have made the rock hotter than that. Some planetary scientists have suggested that the asteroids were porous, and water flowing through a primitive plumbing system cooled them. But the water should have stripped some elements from the rock, ruining their sunlike chemistry.

“It was a paradox,” says planetary scientist Philip Bland of Curtin University of Technology in Perth, Australia.

Bland was modeling how those original globs of ice and dust could have compressed into solid rock, when it hit him: What if they weren’t rock at all?

“At that moment, nothing has happened to force those grains together to turn it into a rock,” he says. That was just something everyone had assumed.

Bland reasoned that heat from radioactive decay would melt the ice, and the resulting body would be an enormous dollop of mud. The mud would suspend sediment particles, so they wouldn’t be stripped of their sunlike elements. And it would allow the early asteroids to be any size and remain cool.

Bland and Bryan Travis of the Planetary Science Institute, who is based in Los Alamos, N.M., ran computer models of how the mud balls would evolve. Convection currents, like those that move molten rock within the Earth’s mantle, would develop, helping to transfer heat into space, the models showed. After several million years, the ball would harden completely, yielding the asteroids seen today.

“It nails the paradox,” Bland says.

Mud balls could even explain the difference between asteroids and comets, he says. Comets, which are more icy than rocky and tend to live farther from the sun, may simply have formed later in the solar system’s history, when there was less radioactive heat available to melt them.

The model also showed that some asteroids would be muddy all the way through, while others would develop cores of larger grains, with a great mud ocean on top of them.

The latter result could describe not just asteroids but bodies like the dwarf planet Ceres, the largest object in the asteroid belt. Observations from NASA’s Dawn spacecraft showed that Ceres has a rocky core and may once have had an ocean that has since evaporated, says UCLA planetary scientist Edward Young. “That process may have been something like what they’re describing.”

Planetary scientist Brandon Johnson of Brown University in Providence, R.I., thinks the model will inspire more research. “I’m interested in it myself, actually,” he says. “It makes a lot of sense and paints a clear picture of what might have been happening.”

But Young is concerned that the model’s flexibility means it won’t make specific enough predictions for future work to test it. “It has so many knobs, you can get it to do whatever you want,” he says. “I’m trying to think of what the killer observation would be.”

source: sciencenews

Watching Cartoons Has Helped Me Manage My Mental Illness

 

More than six years ago, I was diagnosed with generalized anxiety disorder and depression. The traditional approaches ― exercise, journaling and breathing skills ― have helped, as has medication. And I watch cartoons.

 

Yes, this year I discovered a surprising degree of comfort in a 12-year-old boy named Steven Universe.

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When should babies sleep in their own rooms?

baby crying in crib

When we brought our first baby home from the hospital, our pediatrician advised us to have her sleep in our room. We put our tiny new roommate in a crib near our bed (though other containers that were flat, firm and free of blankets, pillows or stuffed animals would have worked, too).

The advice aims to reduce the risk of sleep-related deaths, including sudden infant death syndrome, or SIDS. Studies suggest that in their first year of life, babies who bunk with their parents (but not in the same bed) are less likely to die from SIDS than babies who sleep in their own room. The reasons aren’t clear, but scientists suspect it has to do with lighter sleep: Babies who sleep near parents might more readily wake themselves up and avoid the deep sleep that’s a risk factor for SIDS.

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New heart attack treatment uses photosynthetic bacteria to make oxygen

bac.jpg

Acting like miniature trees that soak up sunlight and release oxygen, photosynthetic bacteria injected into the heart may lighten the damage from heart attacks, a new study in rats suggests.

When researchers injected the bacteria into rats’ hearts, the microbes restored oxygen to heart tissue after blood supply was cut off as in a heart attack, researchers at Stanford University report June 14 in Science Advances.

“It’s really out of the box,” says Himadri Pakrasi, a systems biologist at Washington University in St. Louis who was not involved in the research. “It reads like science fiction to me, but it’s fantastic if it works.”

The organism, called Synechococcus elongatus, has been used recently to produce biofuels, but this may be the first time the cyanobacteria have ever been used in a medical setting, he says.

Other researchers also reacted enthusiastically to the study. “It’s outrageous, but outrageous in a good way,” says Susan Golden, who studies cyanobacteria at the University of California, San Diego. Cardiovascular scientist Matthias Nahrendorf of Massachusetts General Hospital in Boston says, “I enjoy the idea. It’s really fresh.”

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Why Do Men Run Faster Than Women?

sRunning is a sport that both men and women enjoy, whether they’re racing in a 5K or a marathon, or competing for a team or their country while speeding around a track. But no matter the venue, it’s pretty common to see men clock faster times than women do.

Given that both men and women train equally hard, why is it that men, on average, are faster runners than women? Even the world’s fastest man is about a second speedier on the 100-meter dash than the world’s fastest woman: Usain Bolt did it in 9.58 seconds, versus the late Florence Griffith Joyner’s time of 10.49 seconds. Continue reading “Why Do Men Run Faster Than Women?”

Sea creatures’ sticky ‘mucus houses’ catch ocean carbon really fast

 

050317_SM_mucous-house_main_FREE.jpgNever underestimate the value of a disposable mucus house.

Filmy, see-through envelopes of mucus, called “houses,” get discarded daily by the largest of the sea creatures that exude them. The old houses, often more than a meter across, sink toward the ocean bottom carrying with them plankton and other biological tidbits snagged in their goo.

Now, scientists have finally caught the biggest of these soft and fragile houses in action, filtering particles out of seawater for the animal to eat. The observations, courtesy of a new deepwater laser-and-camera system, could start to clarify a missing piece of biological roles in sequestering carbon in the deep ocean, researchers say May 3 in Science Advances. Continue reading “Sea creatures’ sticky ‘mucus houses’ catch ocean carbon really fast”

MARS MAY NOT HAVE BEEN BORN ALONGSIDE THE OTHER ROCKY PLANETS

Mars

Mars may have had a far-out birthplace.

Simulating the assembly of the solar system around 4.56 billion years ago, researchers propose that the Red Planet didn’t form in the inner solar system alongside the other terrestrial planets as previously thought. Mars instead may have formed around where the asteroid belt is now and migrated inward to its present-day orbit, the scientists report in the June 15 Earth and Planetary Science Letters. The proposal better explains why Mars has such a different chemical composition than Earth, says Stephen Mojzsis, a study coauthor and geologist at the University of Colorado Boulder.

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How Would Just 2 Degrees of Warming Change the Planet?

umThe Earth is home to a range of climates, from the scorching dunes of the Sahara to the freezing ridges of Antarctica. Given this diversity, why are climate scientists so alarmed about a worldwide temperature increase of just 2.7 degrees Fahrenheit (1.5 degrees Celsius)?

Changing the average temperature of an entire planet, even if it’s just by a few degrees, is a big deal, said Peter deMenocal, a paleoclimate scientist at Lamont-Doherty Earth Observatory at Columbia University in New York.

“A person living in any one location can experience huge changes in weather and even in climate, but those are often compensated by changes on opposite sides of the world,” deMenocal told Live Science. [Is Global Warming Melting Antarctica’s Ice?] Continue reading “How Would Just 2 Degrees of Warming Change the Planet?”

More Brain Differences Seen Between Girls, Boys With ADHD

Proposed_Symptoms_of_ADHD

Girls and boys with attention-deficit/hyperactivity disorder don’t just behave differently. Parts of their brains look different, too. Now, researchers can add the cerebellum to that mismatch.

For boys, symptoms of the disorder tend to include poor impulse control and disruptive behavior. Girls are more likely to have difficulty staying focused on one task. Studies show that those behavioral differences are reflected in brain structure.  Boys with ADHD, for example, are more likely than girls to display abnormalities in premotor and primary motor circuits, pediatric neurologist Stewart Mostofsky of Kennedy Krieger Institute in Baltimore has reported previously.

Now, Mostofsky and colleagues have looked at the cerebellum, which plays a role in coordinating movement. He reported the new findings March 25 at the Cognitive Neuroscience Society’s annual meeting in San Francisco.

Girls ages 8 to 12 with ADHD showed differences in the volume of various regions of their cerebellum compared with girls without the condition, MRI scans revealed. A similar comparison of boys showed abnormalities, too. But those differences didn’t match what’s seen between girls, preliminary analyses suggest. So far, researchers have looked at 18 subjects in each of the four groups, but plan to quintuple that number in the coming months.

Differences seem most prominent in areas of the cerebellum that control higher-order motor functions, Mostofsky said. Those circuits help regulate attention and plan out behavior, versus directing basics like hand-eye coordination. That could help explain why ADHD affects girls’ behavior differently than boys’.

Source : Sciencenews

WHEN IT COMES TO THE FLU, THE NOSE HAS A LONG MEMORY

Image result for flu

After an influenza infection, the nose recruits immune cells with long memories to keep watch for the virus, research with mice suggests.

For the first time, this type of immune cell — known as tissue resident memory T cells — has been found in the nose, researchers report June 2 in Science Immunology. Such nasal resident memory T cells may prevent flu from recurring. Future nasal spray vaccines that boost the number of these T cells in the nose might be an improvement over current flu shots, researchers say.

It’s known that some T cell sentinels take up residence in specific tissues, including the brain, liver, intestines, skin and lungs. In most of these tissues, the resident memory T cells start patrolling after a localized infection. “They’re basically sitting there waiting in case you get infected with that pathogen again,” says Linda Wakim, an immunologist at the University of Melbourne in Australia. If a previous virus invades again, the T cells can quickly kill infected cells and make chemical signals, called cytokines, to call in other immune cells for reinforcement. These T cells can persist for years in most tissues.

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