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
April 15,2020

Wuhan, Apr 15: In the six days after top Chinese officials secretly determined they likely were facing a pandemic from a new coronavirus, the city of Wuhan at the epicenter of the disease hosted a mass banquet for tens of thousands of people; millions began traveling through for Lunar New Year celebrations.

President Xi Jinping warned the public on the seventh day, Janaury 20. But by that time, more than 3,000 people had been infected during almost a week of public silence, according to internal documents obtained by The Associated Press and expert estimates based on retrospective infection data.

That delay from Jan 14 to Jan. 20 was neither the first mistake made by Chinese officials at all levels in confronting the outbreak, nor the longest lag, as governments around the world have dragged their feet for weeks and even months in addressing the virus.

But the delay by the first country to face the new coronavirus came at a critical time — the beginning of the outbreak. China's attempt to walk a line between alerting the public and avoiding panic set the stage for a pandemic that has infected almost 2 million people and taken more than 126,000 lives.

A This is tremendous, a said Zuo-Feng Zhang, an epidemiologist at the University of California, Los Angeles. If they took action six days earlier, there would have been much fewer patients and medical facilities would have been sufficient. We might have avoided the collapse of Wuhan's medical system.

Other experts noted that the Chinese government may have waited on warning the public to stave off hysteria, and that it did act quickly in private during that time.

But the six-day delay by China's leaders in Beijing came on top of almost two weeks during which the national Center for Disease Control did not register any cases from local officials, internal bulletins obtained by the AP confirm. Yet during that time, from Jan 5 to Jan 17, hundreds of patients were appearing in hospitals not just in Wuhan but across the country.

It's uncertain whether it was local officials who failed to report cases or national officials who failed to record them. It's also not clear exactly what officials knew at the time in Wuhan, which only opened back up last week with restrictions after its quarantine.

But what is clear, experts say, is that China's rigid controls on information, bureaucratic hurdles and a reluctance to send bad news up the chain of command muffled early warnings. The punishment of eight doctors for rumor-mongering, broadcast on national television on Jan. 2, sent a chill through the city's hospitals.

Doctors in Wuhan were afraid, said Dali Yang, a professor of Chinese politics at the University of Chicago. It was truly intimidation of an entire profession. Without these internal reports, it took the first case outside China, in Thailand on Jan 13, to galvanize leaders in Beijing into recognising the possible pandemic before them. It was only then that they launched a nationwide plan to find cases distributing CDC-sanctioned test kits, easing the criteria for confirming cases and ordering health officials to screen patients, all without telling the public.

The Chinese government has repeatedly denied suppressing information in the early days, saying it immediately reported the outbreak to the World Health Organization.

Allegations of a cover-up or lack of transparency in China are groundless, said foreign ministry spokesman Zhao Lijian at a Thursday press conference.

The documents show that the head of China's National Health Commission, Ma Xiaowei, laid out a grim assessment of the situation on Jan. 14 in a confidential teleconference with provincial health officials.

A memo states that the teleconference was held to convey instructions on the coronavirus from President Xi Jinping, Premier Li Keqiang and Vice Premier Sun Chunlan, but does not specify what those instructions were.

The epidemic situation is still severe and complex, the most severe challenge since SARS in 2003, and is likely to develop into a major public health event, the memo cites Ma as saying.

The National Health Commission is the top medical agency in the country. In a faxed statement, the Commission said it had organised the teleconference because of the case reported in Thailand and the possibility of the virus spreading during New Year travel. It added that China had published information on the outbreak in an open, transparent, responsible and timely manner," in accordance with important instructions repeatedly issued by President Xi.

The documents come from an anonymous source in the medical field who did not want to be named for fear of retribution. The AP confirmed the contents with two other sources in public health familiar with the teleconference. Some of the memo's contents also appeared in a public notice about the teleconference, stripped of key details and published in February.

Under a section titled sober understanding of the situation, the memo said that clustered cases suggest that human-to-human transmission is possible. It singled out the case in Thailand, saying that the situation had changed significantly because of the possible spread of the virus abroad.

With the coming of the Spring Festival, many people will be traveling, and the risk of transmission and spread is high, the memo continued.

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News Network
April 12,2020

Apr 12: Pope Francis called on Sunday for an "immediate" ceasefire in global conflict and urged European nations to show "solidarity" in the face of a coronavirus pandemic that has claimed more than 109,000 lives worldwide.

"May Christ our peace enlighten all who have responsibility in conflicts, that they may have the courage to support the appeal for an immediate global ceasefire in all corners of the world," the pope said in a livestreamed Easter message.

Francis added that it was time for Europe, which he described as his "beloved continent", to "rise again, thanks to a concrete spirit of solidarity" similar to that shown after World War II.

Christians around the world are marking a solitary Easter, forced to celebrate the most joyful day in the Christian calendar largely alone amid the sorrowful reminders of the devastation wrought by the coronavirus pandemic

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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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