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
January 6,2020

Sydney, Jan 6: Reserve troops fanned out across fire-ravaged regions in three Australian states on Monday after a horror weekend, as the government pledged $1.4 billion over two years to help recover from the devastating months-long crisis.

Catastrophic bushfires have turned swathes of land into smouldering, blackened hellscapes and destroyed an area about the size of the island of Ireland, according to official figures, with authorities warning the disaster still has weeks or months to run.

Prime Minister Scott Morrison, whose government has been criticised for its slow response to the emergency, pledged Australian $2 billion ($1.4 billion) of taxpayer money for a national recovery fund.

"It's a long road ahead and we will be with these communities every step of the way as they rebuild," Morrison said.

Firefighters joined by fresh teams from the US and Canada were taking advantage of rainy and cooler conditions to tackle out-of-control blazes ahead of rising temperatures forecast later this week.

In the biggest-ever call up of reserves, military teams were deployed across eastern Australia to help emergency services assess the damage, restore power and deliver supplies of food, water and fuel to cut-off communities.

For the first time in Australian history the government also deployed its medical assistance team, normally sent to other nations to lend support in the aftermath of their disasters to help evacuees.

"There is no room for complacency, especially as we have over 130 fires burning across (New South Wales) state still," Premier of New South Wales state Gladys Berejiklian said on Monday.

New normal

Almost five million hectares (50,000 square kilometres) have been razed across New South Wales and more than 1.2 million hectares in Victoria since late September, officials said.

That took the total amount of land burnt close to eight million hectares, around the size of the island of Ireland or South Carolina.

Twenty-four people have lost their lives so far, with over 1,800 homes damaged.

Two people are missing in New South Wales, the nation's most populous state.

In Victoria, Premier Daniel Andrews established a bushfire recovery agency to help devastated towns. It will be a permanent body, he said, as intense fires will become commonplace.

"We should just be honest about the fact that we're going to see more and more fires, more and more damage as each fire season comes... this is the new normal," Andrews told reporters.

The chair of the newly established Victoria state's bushfire appeal fund, Pat McNamara, added that this year's summer bushfire season was a "creeping disaster".

"We're still not even into what we would regard as the peak of the fire season," McNamara told national broadcaster ABC.

In the usually picturesque southeastern town of Eden, Holly Spence said she spent more than 12 hours defending her family's farm on Saturday, less than a week after saving it on New Year's Eve.

"We don't want to go through this for a third time," the 28-year-old told AFP.

Fiona Kennelly, 50, who evacuated with 24 members of her extended family to a motel outside Eden, said she was relieved the easing conditions allowed them to get some respite from the crisis.

"It's good to see daylight at the right time again," she told AFP, adding that the skies had been turning pitch-black in the afternoons.

Public anger

The impact of the bushfires has spread beyond affected communities, with heavy smoke engulfing the country's second-largest city Melbourne and the national capital Canberra.

Some government departments were shut in Canberra as the city's air quality was once-again ranked the world's poorest, according to independent online air-quality index monitor Air Visual.

The disaster has sparked growing public anger with Morrison. Rallies are planned on Friday to call on his government to step up efforts to tackle climate change, which experts say have helped fuel the fires.

In Los Angeles, Hollywood superstar Russell Crowe said he was back home fighting the fires and that the disaster was "climate change-based".

"We need to act on science, move our global workforce to renewable energy and respect our planet for the unique and amazing place it is. That way, we all have a future," he said in a message read out by Jennifer Aniston.

Australian actress Cate Blanchett praised the volunteer firefighters battling the blazes, adding: "When one country faces a climate disaster, we all face a climate disaster. We're in it together."

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News Network
March 11,2020

Rome, Mar 11: Italy has recorded its deadliest day of the coronavirus crisis despite locking down the entire country, as New York deployed the National Guard to contain a disease that has sown worldwide panic.

The hardest-hit country in Europe said its death toll from the COVID-19 virus had risen Tuesday by a third to 631, with the surging epidemic taking its toll on global sporting, cultural and political events.

While authorities in China, where the outbreak began, have declared it "basically curbed", cases are multiplying around the world, sparking panic buying in shops, and wild swings on financial markets.

China remains the hardest-hit overall with more than 80,000 cases and over 3,000 deaths, out of a global total of 117,339 cases and 4,251 deaths across 107 countries and territories, according to an AFP tally.

The virus is infecting all walks of life, including politics, with US Democratic presidential hopefuls Bernie Sanders and Joe Biden both cancelling campaign rallies and British health minister Nadine Dorries saying she had tested positive.

And amid criticism of the US authorities' response, New York deployed the National Guard for the first time during the crisis to help contain the spread of the disease from an infection-hit suburb.

There have been 173 confirmed cases in New York state, including 108 in Westchester County, home to New Rochelle where the majority of infections have been detected.

"It is a dramatic action, but it is the largest cluster in the country. This is literally a matter of life and death," said state governor Andrew Cuomo.

"People are scared, it's an unusual situation to be in," Miles Goldberg, who runs a New Rochelle bar, told AFP.

"It makes people nervous to be around others, it makes people nervous to get inside into businesses and such," he said.

In an unprecedented move, Italian Prime Minister Giuseppe Conte has told the 60 million residents of his country they should travel only for the most urgent work or health reasons.

And while squares in Milan and Rome were emptied of their usual bustle and traffic, some residents appeared uncertain if they were even allowed to leave their homes for everyday tasks like shopping.

The virus has battered tourism around the world, as people scrap travel plans, and a restaurant owner in Florence in northern Italy said that the impact on business had been catastrophic.

"We hope that we will see the end of it, because from around 140 covers a day, this afternoon, we've gone down to 20-25," Agostino Ferrara told AFP.

Pope Francis also seemed to muddy the waters, holding a mass in which he urged priests to go out and visit the sick -- something Conte has specifically discouraged.

Sporting events continued to fall victim to the virus as authorities urge people to avoid large gatherings.

Arsenal's game at Manchester City was postponed after players from the London club were put into quarantine, making it the first Premier League fixture to be called off because of the virus.

The virus has sparked doubts about the Olympics due to open in Tokyo on July 24 and the traditional flame lighting ceremony in Greece is set to be held without spectators.

In the United States, organisers rescheduled the two-week Coachella music festival for October.

The virus and the response to the crisis has prompted pandemonium on global markets with volatility not seen since the world financial crisis in 2008.

After suffering its worst session in more than 11 years at the beginning of the week, the Dow Jones Index in New York bounced back significantly, rising five percent on Tuesday.

Politicians around the world have scrambled to put together emergency packages to ease the significant financial hardships the virus is expected to cause for households and businesses.

US President Donald Trump, who is relying on a strong economy to boost his re-election hopes, promised to announce "major" economic measures on Tuesday.

The biggest item on his wish list is a cut in payroll taxes. But even allies in Congress and reportedly some aides in the White House are sceptical, questioning the cost.

Italy prepared Tuesday to let families skip mortgage and some tax payments while Japan unveiled a second emergency package to tackle economic woes stemming from the outbreak, including $15 billion in loan programmes to support small businesses.

Analysts warned of further volatility ahead however.

"It's like winding up a rubber band. The more you wind it, when you let go, the more it pops," said LBBW's Karl Haeling.

"A lot of the uncertainty goes to the root of the virus itself."

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Agencies
January 25,2020

Washington, Jan 25: US President Donald Trump's legal team was preparing his defence on Saturday after the Democratic prosecutors ended their marathon 24-hour argument to oust him from office during the Senate trial.

In the arguments spread over three days ending on Friday, the Democrat prosecutors from the House of Representatives that had impeached Trump last month, mostly rehashed the testimonies from the hearings before their committees during the investigation and statements in their chamber.

Like the Democrats' arguments, the Trump defence's counter-arguments, also with 24 hours allotted for it, will be mind-numbing monologues for the most part and the real drama will be on a tussle between the two parties on calling witnesses.

The Democrats failed in their repeated attempts on the first day of the trial on January 28 to include calling testimonies from witnesses in the rules of procedure, but they will get another chance to press their case when the defence rests.

There is a tense wait speckled with speculations to see if the Democrats can get four Republicans to defect and vote to call witnesses after failing to sway a mass defection to get the two-thirds majority to convict Trump.

Trump is charged with abuse of power and obstruction of Congress in the trial presided over by Supreme Court Chief Justice John Roberts with the Senators acting as jurors.

As the time allotted for the prosecution wound down on Friday, the leading prosecutor, Adam Schiff, demanded that the Republican-controlled Senate convict and remove Trump from office, because he was an "imminent threat" to the US and the nation could not wait for the election to throw him out.

Schiff, who heads the House Intelligence Committee that investigated Trump, gave them a personal warning: "No matter how close you are to this president, do you think for a moment that if he felt it was in his interest, he wouldn't ask you to be investigated?

Jerry Nadler, the head of the Judicial Committee that framed the charges in the impeachment, called Trump a "dictator".

Instead of a full sitting of eight hours, the defence will present its case for only two to three hours on Saturday in what Trump's lawyer Jay Sekulow called a "trailer (for) coming attractions" in the defence counterarguments.

They will get to use their remaining time next week.

The shorter session starting with fuller presentations next week is partly a concession to media savvy Trump who tweeted that daytime Saturday when his defence was slated is a "death valley" on TV as few viewers would watch a political event at that time.

With Trump certain to be acquitted because the Democrats do not have the two-thirds vote, the impeachment process and the Senate trial are only meant to be an extended media show in their campaign for the November election.

The Democrats want to spiff up the TV spectacle by calling former National Security Adviser John Bolton and Trump's acting Chief of Staff Mick Mulvaney as witnesses.

Trump could exercise his executive privilege to stop them from testifying, in which case they could go to court to compel their appearance at the Senate trial extending its duration by months if not weeks.

The House charged him with obstruction of Congress because he refused to allow some of this staff to testify and release documents requested by the House investigators.

The Republicans, who want a quick end to the trial, can also counter the Democrats' request for witnesses by calling former Vice President Joe Biden and his son, Hunter, to testify in order to embarrass them and their party.

The Bidens are at the root of the abuse of power charges against Trump.

Trump had asked newly-elected Ukrainian President Volodymyr Zelentsky in a July phone call to investigate the Bidens' dealings in his country as a "favour".

Democrats say that this was inviting foreign intervention in US elections because Joe Biden is the leading Democratic party candidate for the nomination to oppose him.

Moreover, they say that he froze about $400 million in Congressionally-approved military aid for pressure Zelentsky to order the probe and this endangered US national security as Ukraine is at war with Russia.

chiff and the other prosecutors said delaying the aid was an attempt at a quid pro quo.

Zelentsky has said that he did not feel pressured by Trump.

Hunter Biden, who was removed from the Navy allegedly due to drug use and had no energy business experience landed a directorship in a Ukrainian gas company with monthly payments reportedly between $50,000 and $83,000 while his father was overseeing Washington's dealings with Kiev.

The former Vice President has publicly admitted that he got the Ukrainian leaders to fire the prosecutor investigating his son's company.

The Republicans have said that the son's appointment was unethical and the father had the prosecutor removed to protect his son's company.

In their arguments, the Democratic prosecutors said there was nothing wrong in Hunter Biden getting the job and his father had the prosecutor dismissed because he was corrupt.

The defence team is expected to assert that Trump withheld the aid because he wanted to be sure that the new government was not corrupt and the aid was released without a probe.

Anticipating the argument, Schiff said that Trump had allowed the aid to go forward only because it became known and his intent still made him guilty.

In another development impinging on the Trump case, a secret recording said to be of the president ordering the firing of Marie Yovanovitch as US ambassador to Ukraine in 2018 has surfaced.

She was one of the witnesses at the House investigations of the charges against Trump.

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