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Kyva Go
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Leptin resistance is a hallmark of human obesity.
Mice that lacked the Rap1 gene and ate a high-fat diet did not develop leptin resistance; they were able to respond to leptin, and this was reflected in the hormone's lower blood levels.

Fukuda and colleagues also tested the effect of inhibiting Rap1 with drugs instead of deleting the gene on mice on a high-fat diet. The scientists inhibited RAP1 action with inhibitor ESI-05.

"When we administered ESI-05 to obese mice, we restored their sensitivity to leptin to a level similar to that in mice eating a normal diet. The mice ate less and lost weight," said Fukuda.

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The UCI group studied the Hungarian researchers' data as well as all other previous experiments in this area and showed that the evidence strongly disfavors both matter particles and dark photons. They proposed a new theory, however, that synthesizes all existing data and determined that the discovery could indicate a fifth fundamental force. Their initial analysis was published in late April on the public arXiv online server, and a follow-up paper amplifying the conclusions of the first work was released Friday on the same website.

The UCI work demonstrates that instead of being a dark photon, the particle may be a "protophobic X boson." While the normal electric force acts on electrons and protons, this newfound boson interacts only with electrons and neutrons - and at an extremely limited range. Analysis co-author Timothy Tait, professor of physics & astronomy, said, "There's no other boson that we've observed that has this same characteristic. Sometimes we also just call it the 'X boson,' where 'X' means unknown."

Feng noted that further experiments are crucial. "The particle is not very heavy, and laboratories have had the energies required to make it since the '50s and '60s," he said. "But the reason it's been hard to find is that its interactions are very feeble. That said, because the new particle is so light, there are many experimental groups working in small labs around the world that can follow up the initial claims, now that they know where to look."

Like many scientific breakthroughs, this one opens entirely new fields of inquiry.

One direction that intrigues Feng is the possibility that this potential fifth force might be joined to the electromagnetic and strong and weak nuclear forces as "manifestations of one grander, more fundamental force."


Read more at: http://phys.org/news/2016-08-physicists-discovery-nature.html#jCp

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This “proton radius puzzle” suggests there may be something fundamentally wrong with our physics models. And the researchers who discovered it have now moved on to put a muon in orbit around deuterium, a heavier isotope of hydrogen. They confirm that the problem still exists, and there's no way of solving it with existing theories.

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Recent DNA studies suggest that the animals arrived in Australia from Borneo and Sulawesi between 5000 and 12,000 years ago. Meanwhile, a 2014 report found that dingoes lack multiple copies of a starch digestion gene; their doggie cousins developed multiple copies while living with agricultural people. The fact that dingoes aren’t able to digest starch suggests that before their journey to Australia they were not living with agricultural people such as the mariners from India, or the traders from Taiwan or Timor.

Since the 1600s, people from south Sulawesi visited north Australia “until the Australian government forbade it in 1900” which suggests Sulawesi hunter-gatherers brought the dingo to Australia 4000 years ago, perhaps after obtaining it from neighbors in Borneo. Here, the archaeological data bolster the case: Similarities in rock art between Sulawesi and Borneo indicate a close connection between the people. What’s more, 8000- to 1500-year-old tools and toolmaking materials unearthed in south Sulawesi confirm that the local hunter-gatherers were able to travel vast distances by sea.

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To pull off the magnetic mental yanking, Güler and colleagues engineered a magnet-responsive ion channel. In brain cells, ion channels are key to building up electrical charges responsible for zapping signals through neural circuitry. The researchers did some genetic surgery on an ion channel known to be responsive to mechanical pressure, called TRPV4. The researchers fused the gene for TRPV4 to a gene for an iron-hoarding protein called ferritin, which is slightly responsive to external magnets (paramagnetic).

With a few more genetic tweaks, the resulting hybrid protein, dubbed Magneto, proved to be viable and responsive to magnetic fields in cells. When the researchers moved a magnet near the cells carrying the hybrid, Magneto jerked, opening the ion channel. This caused an influx of ions into the cells, sparking an electrical change that could fire off brain signals.

When the researchers put the gene for Magneto in zebrafish, a model organism for brain development, they found that the hybrid could alter complex behaviors. Using a genetic switch, the researchers made Magneto active in the zebrafish nerve cells that are involved in sensing touch. And, when they added a magnetic field, the fish upped the amount of time they coiled their tails, a touch-induced escape response.

The researchers next tested Magneto in mice, a mammalian model. By making Magneto active in cells that are responsive to dopamine—a neurotransmitter critical for reward-motivation pathways in the brain—the researchers could charm the mice into preferring an area of a chamber with a magnetic field.

While the results show that the method can work in living animals, Güler and colleagues hope to continue to hone the method, making Magneto even more sensitive to magnetic fields in specific neural circuits. Such improvements “will position the field to better understand neural development, function and pathology,” the authors concluded.

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The female tract prepares sperm for fertilization, requiring researchers to simulate those conditions in the lab. Nagashima and Skylar Sylveste, found that by adding magnesium to the cell culture, it properly prepared the sperm. The final challenge for the researchers was freezing the embryos. Travis and colleagues delivered Klondike, the first puppy born from a frozen embryo in the Western Hemisphere in 2013. Freezing the embryos allowed the researchers to insert them into the recipient's oviducts (called Fallopian tubes in humans) at the right time in her reproductive cycle, which occurs only once or twice a year.

The findings have wide implications for wildlife conservation because, Travis said, "We can freeze and bank sperm, and use it for artificial insemination. We can also freeze oocytes, but in the absence of in vitro fertilization, we couldn't use them. Now we can use this technique to conserve the genetics of endangered species."

In vitro fertilization allows conservationists to store semen and eggs and bring their genes back into the gene pool in captive populations. In addition to endangered species, this can also be used to preserve rare breeds of show and working dogs.

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Hualianceratops lived approximately 160 million years ago (early in the Late Jurassic Period), and the evolutionary relationships the researchers discovered for the new species and other ceratopsians indicate that several lineages of ceratopsians were present at the same time, including the diverse group Neoceratopsia that dominated the Late Cretaceous.

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"The resurrection plant controls the levels of autophagy to prevent death upon drying," Professor Mundree said.

"Our analysis directly linked the accumulation of trehalose with the onset of autophagy in dehydrated and dried out T. loliiformis shoots."Presumably, once induced, autophagy promotes desiccation tolerance in the grass, by recycling nutrients and removing cellular toxins to suppress programmed cell death.
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