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
February 9,2020

Nakhon Ratchasima, Feb 9: The Thai soldier who killed at least 20 people and holed up in a mall overnight was shot dead Sunday morning by commandos, ending a near-17-hour ordeal which left dozens wounded and stunned the country.

It was unclear how many people remained trapped inside the Terminal 21 mall in Nakhon Ratchasima -- also known as Korat -- where the gunman held out through the night, armed with assault weapons stolen from his barracks.

Volleys of gunfire rang out as the siege ran into dawn, hours after Thai security services stormed the ground floor and freed scores of stunned, terrified shoppers from a bloody rampage that the gunman -- a junior army officer identified as Sergeant-Major Jakrapanth Thomma -- had relayed via Facebook posts.

"He was shot dead thirty minutes ago" (0200 GMT), chief of the Crime Suppression Division Jirabhob Bhuridej told AFP.

Commandos from elite Thai police units killed the gunman, a police spokesman added, after an operation involving hundreds of security personnel.

"The official death toll is 20 and wounded 42... nine are in surgery," Narinrat Pitchayakamin, a Korat doctor told reporters, revising down an initial death toll of 21.

But it was unclear if there were more victims inside the multi-level complex which was packed with Saturday shoppers when the gunman stormed in.

A fleet of ambulances left the front of the complex and forensic police poured into the grim crime scene, shortly before the gunman's death was confirmed.

The night was peppered with heavy exchanges of gunfire and sporadic evacuations.

A police officer who took part in a raid to flush out the gunman died, according to deputy prime minister Anutin Charnvirakul. "He had been hit and unfortunately, he couldn't make it," said Anutin.

Shocked evacuees recounted how an ordinary Saturday shopping day at the busy mall descended into horror as the gunman entered.

"It was like a dream... I'm grateful I survived," Sottiyanee Unchalee, 48, told AFP, explaining she hid in the toilet of a gym inside the mall as she heard the gunfire.

"I'm so sorry for those who died... (and) the people still trapped inside."

Stolen weapons

Jakrapanth relayed his shooting spree through Facebook posts which charted the attack from the army barracks in the city to the mall, where an unknown number of shoppers remained trapped.

A volunteer rescue worker recounted a bloody scene of horror after his team carried four corpses to the hospital.

"I've never seen anything like this," Peerapong Chatadee told AFP.

"I just feel so sad. He is a soldier, he should not have fired at unarmed people."

The bloodshed began Saturday afternoon when Jakrapanth shot three people -- among them at least one soldier -- at a senior officer's house and then at the nearby army barracks, before driving an army vehicle to the town centre.

There the gunman used weapons stolen from the military arsenal to unleash carnage in the town centre.

He "used a machine gun and shot innocent victims resulting in many injured and dead", said police spokesman Krissana Pattanacharoen.

Throughout the day, Jakrapanth posted images of himself and wrote several posts on his Facebook page as the attack unfolded.

In one Facebook video -- since deleted -- the assailant, wearing an army helmet, filmed from an open-top jeep, saying, "I'm tired... I can't pull my finger anymore" as he made a trigger symbol with his hand.

There were also photos of a man in a ski mask holding up a pistol.

A Facebook spokesperson said: "We have removed the gunman's accounts from our services and will work around the clock to remove any violating content related to this attack as soon as we become aware of it."

The city is home to one of the largest barracks in Thailand, a country where the military is enmeshed in politics and society.

The nation also has one of the highest rates of gun ownership in the world, and several shootings at courthouses last year renewed concern about gun violence.

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News Network
April 24,2020

Washington, Apr 24: President Donald Trump has favoured a phased reopening of the US economy, devastated by the coronavirus pandemic, which has claimed nearly 50,000 lives and infected over eight lakh people in the country.

More than 95 per cent of the country's 330 million people are under stay-at-home order as a result of the social mitigation measures, including social distancing, being enforced till May 1.

Trump on Thursday indicated that the stay-at-home order might be extended beyond May 1, but vehemently advocated the need to gradually open up the economy.

In the past few weeks, more than 26 million Americans have filed for unemployment benefits and the figure is soon likely to cross 40 million.

Both the World Bank and the International Monetary Fund (IMF) have projected a negative growth in the US in 2020.

To keep America gaining momentum, every citizen needs to maintain the vigilance, and we all understand that very well we've gone over it many, many times this includes practising good hygiene, maintaining social distance, and the voluntary use of face covering, Trump said.

Safe and phased reopening of our economy -- it's very exciting, but it does not mean that we are letting down our guard at all in any way; on the contrary, continued diligence is an essential part of our strategy to get our country back to work to take our country back, he told reporters at his daily White House news conference on coronavirus.

The data and facts on the ground suggest that the US is making great progress, he said.

In 23 states, new cases have declined. In the peak week, 40 per cent of the American counties have seen a rapid decline in new cases. As many as 46 states report a drop in patients showing coronavirus-like symptoms, he said.

Trump said the US is very close to finding a vaccine for COVID-19.

We are very close to testing... when testing starts it takes a period of time but we will get it done, he said.

According to Vice President Mike Pence, data continues to show promising signs of progress in the New York Metro area, New Jersey, Connecticut, Detroit and New Orleans. All appear to be passed their peak and we are seeing consistent declines in hospitalisation and cases in regions across the country, he said.

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Agencies
February 11,2020

The head of the World Health Organisation on Tuesday warned the novel coronavirus was a "very grave threat" for the world as he opened a conference to combat the epidemic.

"With 99% of cases in China, this remains very much an emergency for that country, but one that holds a very grave threat for the rest of the world," Tedros Adhanom Ghebreyesus said in Geneva.

Some 400 scientists will review how the virus is transmitted and possible vaccines at the two-day forum.

"What matters most is stopping the outbreak and saving lives. With your support, that's what we can do together," Tedros said.

The virus, first identified in China on December 31, has killed more than 1,000 people, infected over 42,000 and reached some 25 countries.

Participants will also discuss the source of the virus, which is thought to have originated in bats and reached humans via another animal such as snakes or pangolins.

There is no specific treatment or vaccine against the virus, which can cause respiratory failure.

Tedros, who has repeatedly urged countries affected to share their data, called for global "solidarity".

"That is especially true in relation to the sharing of samples and sequences. To defeat this outbreak, we need open and equitable sharing, according to the principles of fairness and equity," he said.

"We hope that one of the outcomes of this meeting will be an agreed roadmap for research around which researchers and donors will align," Tedros said.

Several companies and institutes in Australia, China, France, Germany and the United States are racing to develop a vaccine -- a process that normally takes years.

Asked whether scientists from Taiwan would be allowed to take part in this week's Geneva conference, WHO officials said that they would do so but only online -- along with colleagues from other parts of China.

While the WHO does not deal with Taiwan directly and only recognises Beijing, Taiwan was often allowed to attend annual assemblies and sideline meetings as an observer.

But in recent years it has been frozen out as Beijing takes an increasingly combative stance towards democratic Taiwan, which it considers its own territory.

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