More reasons to get a goodnight's rest. Sleep-deprived brain can't form memories

February 13, 2017

Washington, Feb 13: If you don't get enough sleep, you might just start forgetting things. Sleep deprivation can interfere with the process that helps reinforce our memories, a new study has found.

sleepAfter studying mice, researchers at Johns Hopkins University in the US have fortified evidence that a key purpose of sleep is to recalibrate the brain cells responsible for learning and memory so the animals can ‘solidify' lessons learned and use them when they awaken.

The researchers also report they have discovered several important molecules that govern the recalibration process, as well as evidence that sleep deprivation, sleep disorders and sleeping pills can interfere with the process.

“Our findings solidly advance the idea that the mouse and presumably the human brain can only store so much information before it needs to recalibrate,” said Graham Diering from Johns Hopkins University.

“Without sleep and the recalibration that goes on during sleep, memories are in danger of being lost,” said Diering.

Diering said that current scientific understanding of learning suggests that information is “contained” in synapses, the connections among neurons through which they communicate.

On the “sending side” of a synapse, signalling molecules called neurotransmitters are released by a brain cell as it “fires”; on the “receiving side,” those molecules are captured by receptor proteins, which pass the “message” along.

If a cell receives enough input through its synapses, it fires off its own neurotransmitters.

More specifically, experiments in animals have shown that the synapses on the receiving neuron can be toggled by adding or removing receptor proteins, thereby strengthening or weakening them and allowing the receiving neuron to receive more or less input from nearby signalling neurons.

When neurons are “maxed out” and constantly firing, they lose their capacity to convey information, stymying learning and memory. One possible reason that neurons do not usually max out is a process that has been well-studied in lab-grown neurons but not in living animals, asleep or awake.

Known as homeostatic scaling down, it is a process that uniformly weakens synapses in a neural network by a small percentage, leaving their relative strengths intact and allowing learning and memory formation to continue.

To find out if the process does occur in sleeping mammals, Diering focused on the areas of the mouse brain responsible for learning and memory: the hippocampus and the cortex.

He purified proteins from receiving synapses in sleeping and awake mice, looking for the same changes seen in lab-grown cells during scaling down.

Results showed a 20% drop in receptor protein levels in sleeping mice, indicating an overall weakening of their synapses, compared to mice that were awake.

The study appears in the journal Science.

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News Network
June 17,2020

Beijing, Jun 17: China said Wednesday it wanted to avoid further clashes with India along their border after the first deadly confrontation between the two nuclear powers in decades.

The two countries have traded blame for Monday's high-altitude brawl that left at least 20 Indian soldiers dead, with China refusing to confirm so far whether there were any casualties on its side.

Chinese foreign ministry spokesman Zhao Lijian insisted again Wednesday that it was Indian troops who illegally crossed the border and attacked the Chinese side.

This led to "a serious physical confrontation between both sides that caused deaths and injuries", Zhao said at a regular briefing, without providing more details about the casualties.

He said China urges India to "strictly restrain frontline troops, do not illegally cross the border, do not make provocative gestures, do not take any unilateral actions that will complicate the border situation".

But he added that the two sides "will continue to resolve this issue through dialogue and negotiations".

"We of course don't wish to see more clashes," Zhao said.

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Indian baba
 - 
Wednesday, 17 Jun 2020

we have 56 inch chest man as our leader...he alone will fight the war and give victory to india..jai bakth

 

 

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Agencies
June 6,2020

Seoul, Jun 6: South Korea on Saturday reported 51 new cases of COVID-19, mostly in the densely populated capital region, as authorities scramble to stem transmissions among low-income workers who can't afford to stay home.

The figures announced by South Korea's Centers for Disease Control and Prevention brought national totals to 11,719 workers and 273 deaths.

At least 34 of the new coronavirus cases were linked to door-to-door sellers hired by Richway, a Seoul-based health product provider.

Vice Health Minister Kim Gang-lip said the spread of the virus among Richway sellers was particularly alarming as most of them are in their 60s and 70s. He called for officials to strengthen their efforts to find and examine workplaces vulnerable to infections.

More than 120 infections have also been linked to a massive warehouse operated by Coupang, a local e-commerce giant, which has been accused of failing to properly implement preventive measures and having employees work even when sick.

South Korea was reporting around 500 new cases per day in early March due to a massive outbreak surrounding the southern city of Daegu, before officials managed to stabilize the situation with aggressive tracking and testing.

But the recent resurgence of COVID-19 in the greater capital area, where about half of South Korea's 51 million people live, is now threatening to erase some of the country's hard-won gains. It has also led to second-guessing whether officials were too quick to ease social distancing and reopen schools.

Health authorities and hospital officials on Friday participated in a table-top exercise for sharing hospital capacities between Seoul and nearby cities and ensure swift transports of patients so that a spike of cases in one area doesn't overwhelm its hospital system. 

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News Network
June 9,2020

Washington, Jun 9: When epidemiologists talked about "flattening the curve," they probably didn't mean it this way: the US hit its peak coronavirus caseload in April, but since that time the graph has been on a seemingly unending plateau.

That's unlike several other hard-hit countries which have successfully pushed down their numbers of new cases, including Spain and Italy, which now have bell-shaped curves.

Experts say the prolonged nature of the US epidemic is the result of the cumulative impact of regional outbreaks, as the virus that started out primarily on the coasts and in major cities moves inward.

Layered on top of that are the effects of lifting lockdowns in parts of the country that are experiencing rising cases, as well as a lapse in compliance with social distancing guidelines because of economic hardship, and in some cases a belief that the threat is overstated.

"The US is a large country both in geography and population, and the virus is at very different stages in different parts of the country," Tom Frieden, a former director of the Centers for Disease Control and Prevention told AFP.

The US saw more than 35,000 new cases for several days in April. While that figure has declined, it has still been exceeding 20,000 regularly in recent days.

By contrast, Italy was regularly hitting more than 5,000 cases per day in March but is currently experiencing figures in the low hundreds.

"We did not act quickly and robustly enough to stop the virus spreading initially, and data indicate that it travelled from initial hotspots along major transport routes into other urban and rural areas," added Frieden, now CEO of the non-profit Resolve to Save Lives.

To wit: the East Coast states of New York, New Jersey and Massachusetts accounted for about 50 percent of all cases until about a month or so ago -- but now the geographic footprint of the US epidemic has shifted to the Midwest and southeast, including Florida.

Another key problem, said Jennifer Nuzzo, an epidemiologist at Johns Hopkins, is that the United States is still not doing enough testing, contact tracing and isolation.

After coming late to the testing party -- for reasons ranging from technical issues to regulatory hurdles -- the US has now conducted more COVID-19 tests than any other country.

It even has one of the highest per capita rates per country of 62 per 1,000 people, according to the website ourworldindata.org -- better than Germany (52 per 1,000) and South Korea (20 per 1,000).

But according to Nuzzo, these numbers are misleading, because "the amount of testing that a country should do should be scaled to the size of its epidemic.

"The United States has the largest epidemic in the world so obviously we need to do a lot more testing than any other country."

For Johns Hopkins, the more important metric is the positivity rate -- that is, out of all tests conducted, how many came back positive for COVID-19.

As of June 7, the United States had an average daily positivity rate of 14 percent, well above the World Health Organization guideline of 5 percent over two weeks before social distancing guidelines should be relaxed.

By contrast, Germany, which has tested far fewer people in relation to its population, has a positivity rate of 5 percent.

Even if testing were scaled up, carrying out tests in of itself does very little good without the next steps -- finding out who was exposed and then asking them to isolate.

Here also, too many US states are lagging woefully behind.

Texas, which is experiencing a surge in cases after relaxing its lockdown, is a case in point. The state targeted hiring a modest 4,000 tracers by June, but according to local reports is still more than a thousand shy of even that goal.

Opt-in app based efforts have also been slow to get off the ground.

Then there is the fact that some people are growing tired of lockdowns, while others don't have the economic luxury of being able to stay home for prolonged periods.

The government sent some 160 million Americans a single stimulus check of up to $1,200 back in April but it's not clear whether more will be forthcoming.

Still others, particularly in so-called red states under Republican leadership, have chafed under restrictions and mask-wearing guidelines that they see as an affront to their personal freedom.

"The US is kind of on the extreme of the individual liberty side," Sten Vermund, dean of the Yale School of Public Health, told AFP.

Part of this has to do with mixed messaging from Republican leaders, including President Donald Trump, said Nuzzo.

"We have had at the highest political level an assertion that this is a situation that's been overblown, and that maybe certain protective behaviors are not necessary," she said.

More recently, tens of thousands of people across the country have taken to the streets to protest the killing on an unarmed black man by police, risking coronavirus infection to demonstrate against the public health threat of racialized state violence.

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