Kids Trying To Hide
Awesome. Can't wait to check it out.
Watch the Perseid Meteor Shower at Its Peak Tonight
The last time we had an outburst, that is a meteor shower with more meteors than usual, was in 2009. This year’s Perseid meteor shower is predicted to be just as spectacular starting tonight!
Plan to stay up late tonight or set your alarm clock for the wee morning hours to see this cosmic display of “shooting stars” light up the night sky. Known for it’s fast and bright meteors, tonight’s annual Perseid meteor shower is anticipated to be one of the best meteor viewing opportunities this year.
For stargazers experiencing cloudy or light-polluted skies, a live broadcast of the Perseid meteor shower will be available via Ustream overnight tonight and tomorrow, beginning at 10 p.m. EDT.
“Forecasters are predicting a Perseid outburst this year with double normal rates on the night of Aug. 11-12,” said Bill Cooke with NASA’s Meteoroid Environments Office in Huntsville, Alabama. “Under perfect conditions, rates could soar to 200 meteors per hour.”
Every Perseid meteor is a tiny piece of the comet Swift-Tuttle, which orbits the sun every 133 years. When Earth crosses paths with Swift-Tuttle’s debris, specks of comet-stuff hit Earth’s atmosphere and disintegrate in flashes of light. These meteors are called Perseids because they seem to fly out of the constellation Perseus.
Most years, Earth might graze the edge of Swift-Tuttle’s debris stream, where there’s less activity. Occasionally, though, Jupiter’s gravity tugs the huge network of dust trails closer, and Earth plows through closer to the middle, where there’s more material.
This is predicted be one of those years!
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Close encounters of the third kind.
Milky Way over Devils Tower
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“The eight day excursion was the beginning of humanity’s journey beyond our home world. Although we have yet to go farther under our own power than we did in the heyday of the Apollo program, our technology, science, dreams and ambition have only continued to grow. If we put the resources into it, human exploration of Mars, of Jovian and Saturnian satellites, or even of worlds beyond our Solar System might become a reality by the end of the 21st century. On the anniversary of the Apollo landings, it’s up to us to remember: it’s our Universe, too, and it’s up to us to make sure we extend our reach beyond the planet we were born onto.”
Less than a decade after the first human was launched into space, astronauts Neil Armstrong, Buzz Aldrin and Michael Collins journeyed from the Earth to the Moon. For the first time, human beings descended down to the lunar surface, opened the hatch, and walked outside. Humanity had departed Earth and set foot onto another world. While Armstrong and Aldrin walked on the surface, collecting now-iconic photos, deploying science instruments and returning hundreds of pounds of lunar samples, Michael Collins orbited overhead, embarking on a missing that no human being had undertaken before. Forty-seven years later, humanity has never had a bigger breakthrough as far as crewed space exploration goes.
Big moon rising.
Brain cells that aid appetite control identified
It’s rare for scientists to get what they describe as “clean” results without spending a lot of time repeating the same experiment over and over again. But when researchers saw the mice they were working with doubling their weight within a month or two, they knew they were on to something.
“About twenty years ago there was a big step forward in our understanding of obesity when researchers discovered that our appetite is controlled by a key molecule called leptin. Leptin is a hormone which is produced by our fat cells, and is delivered by the blood to the brain to signal the brain that we are full and can stop eating,” explains Dr. Maia Kokoeva who is affiliated both with McGill University and the Research Institute of the McGill University Health Centre. “But even though receptors for leptin were discovered soon after in the hypothalamus, a brain area that regulates food intake and body weight, it has remained unclear how exactly leptin is detected.”
So about four years ago, Kokoeva and her team set out to explore which brain cells might play a role in the process of leptin sensing and weight gain. The answer, it turns out, lies in the median eminence.
“Protection” and “preservation” cells in a busy place
The median eminence is a brain structure at the base of the hypothalamus. It is a bit like a busy hub or market place through which hormones and molecules of various kinds travel in both directions between the brain and the bloodstream to ensure that the body functions smoothly.
The McGill research team has now discovered that without a particular group of cells (known as NG2-glia cells) in place in the median eminence, the leptin receptors in the brain never receive the messages from the body telling it that it is sated.
“Most of the brain is a well-protected fortress, designed to shelter delicate nerve cells,” says Kokoeva. “The median eminence is outside these protections, and so can be a dangerous environment for the nerve cells that detect leptin. We think that the NG2-glia cells act to support and shelter the leptin receptor neurons, enabling them to instruct the body when to stop eating.”
Crucial role of the median eminence in weight gain
“We developed an interest in NG2-glia cells in this specific part of the brain because unlike neurons, during much of our adult lives these cells are constantly dividing and they do so most actively in the median eminence,” says Tina Djogo, a McGill doctoral student and one of two lead authors on the study which was published in Cell Metabolism. “But though these cells were first described about thirty years ago it has been difficult so far to pinpoint their exact functions in the adult brain.”
Because of their particularly high turnover in the median eminence, the researchers wondered if the NG2-glia cells might play a role in leptin sensing and therefore in appetite control. So they used a drug to kill the NG2-glia cells in the median eminence of a group of mice and then watched to see whether there was a difference in food intake. The results were stunning.
Within three days after they started to receive the medication, some of the mice dubbed “gainers” had already started to eat more compared with the control group of mice who had not received medication. And by 30 days afterwards, the weight of some of the mice had doubled - from 25 grams to around 50 grams.
“But what was most exciting to us, was that even though NG2-glia are found across the brain” explains Sarah Robins, a research associate who was also a lead author on this study, “it was only when we removed these cells from the median eminence that we saw this clear increase in body weight.”
A possible explanation for weight gain in brain tumour patients
The researchers then corroborated the role of the NG2-glia cells in the median eminence in appetite control through experiments using genetically modified mice, and also by using irradiation. This latter discovery suggested an explanation for a previously unexplained phenomenon in human brain cancer survivors.
“People who have been treated for brain tumours using radiation to block cell proliferation often become overweight,” says Kokoeva. “However, there has never been any satisfactory explanation, but our experiments in mice now suggests that the reason for this weight gain may be the loss of NG2-glia in the median eminence as a result of radiation.”
The researchers are hopeful that the identification of NG2-glia in the median eminence as crucial elements in body weight and appetite control will pave the way to new targeted anti-obesity approaches directed towards maintaining or raising the NG2-glia population in the median eminence.
The Aral Sea was once the fourth-largest lake in the world. Fed primarily by snowmelt and precipitation flowing down from faraway mountains, it was a temperate oasis in an arid region. But in the 1960s, the Soviet Union diverted two major rivers to irrigate farmland, cutting off the inland sea from its source. As the Aral Sea dried up, fisheries collapsed, as did the communities that depended on them. The remaining water supply became increasingly salty and polluted with runoff from agricultural plots. Loss of the Aral Sea’s water influenced regional climate, making the winters even colder and the summers much hotter.
While seasonal rains still bring water to the Aral Sea, the lake is roughly one-tenth of its original size. These satellite images show how the Aral Sea and its surrounding landscape has changed over the past few decades.
For more details about these images, read the full stories here: https://go.nasa.gov/2PqJ1ot
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Nice
Cute ! 💖🖤💚
Reminds me of me when I was younger. lol.