Questões de Concursos

T E X T

EL TIGRE, Venezuela — Thousands of workers are fleeing Venezuela’s state-owned oil company, abandoning once-coveted jobs made worthless by the worst inflation in the world. And now the hemorrhaging is threatening the nation’s chances of overcoming its long economic collapse.

Desperate oil workers and criminals are also stripping the oil company of vital equipment, vehicles, pumps and copper wiring, carrying off whatever they can to make money. The double drain — of people and hardware — is further crippling a company that has been teetering for years yet remains the country’s most important source of income.

The timing could not be worse for Venezuela’s increasingly authoritarian president, Nicolás Maduro, who was re-elected last month in a vote that has been widely condemned by leaders across the hemisphere. Prominent opposition politicians were either barred from competing in the election, imprisoned or in exile.

But while Mr. Maduro has firm control over the country, Venezuela is on its knees economically, buckled by hyperinflation and a history of mismanagement. Widespread hunger, political strife, devastating shortages of medicine and an exodus of well over a million people in recent years have turned this country, once the economic envy of many of its neighbors, into a crisis that is spilling over international borders.

If Mr. Maduro is going to find a way out of the mess, the key will be oil: virtually the only source of hard currency for a nation with the world’s largest estimated petroleum reserves. But each month Venezuela produces less of it. Offices at the state oil company are emptying out, crews in the field are at half strength, pickup trucks are stolen and vital materials vanish. All of this is adding to the severe problems at the company that were already acute because of corruption, poor maintenance, crippling debts, the loss of professionals and even a lack of spare parts.

Now workers at all levels are walking away in large numbers, sometimes literally taking piecesof the company with them, union leaders, oil executives and workers say.

A job with Petróleos de Venezuela, known as Pdvsa, used to be a ticket to the Venezuelan Dream. No more.

Inflation in Venezuela is projected to reach an astounding 13,000 percent this year, according to the International Monetary Fund. When The New York Times interviewed Mr. Navas in May, the monthly salary for a worker like him was barely enough to buy a whole chicken or two pounds of beef. But with prices going up so quickly, it buys even less now.

Junior Martínez, 28, who has worked in the oil industry for eight years, is assembling papers, including his diploma as a chemical engineer. His wife and her daughter left three months ago to earn money in Brazil. “I get 1,400,000 bolívars a week and it isn’t even enough to buy a carton of eggs or a tube of toothpaste,”Mr. Martínez said of his salary in bolívars, Venezuela’s currency.

Mr. Martínez’s father, Ovidio Martínez, 55, recalled growing up here when the oil boom began. He cried as he spoke of his son’s determination to leave the country. “You watch your children leave and you can’t stop them,” the elder Mr. Martínez said, fighting back tears. “In this country, they don’t have a future.”

In El Tigre, hundreds of people stood in line one recent morning outside a supermarket, many waiting since the evening before to buy whatever food they could.

From: www.nytimes.com/June 14, 2018. Adapted.

The World Might Be Running Low on Americans

The world has been stricken by scarcity. Our post-pandemic pantry has run bare of gasoline, lumber, microchips, chicken wings, ketchup packets, cat food, used cars and Chickfil-A sauce. Like the Great Toilet Paper Scare of 2020, though, many of these shortages are the consequence of near-term, Covid-related disruptions. Soon enough there will again be a chicken wing in every pot and more than enough condiments to go with it.

But there is one recently announced potential shortage that should give Americans great reason for concern. It is a shortfall that the nation has rarely had to face, and nobody quite knows how things will work when we begin to run out.

I speak, of course, of all of us: The world may be running low on Americans — most crucially, tomorrow’s working-age, childbearing, idea-generating, community-building young Americans. Late last month, the Census Bureau released the first results from its 2020 count, and the numbers confirmed what demographers have been warning of for years: The United States is undergoing “demographic stagnation,” transitioning from a relatively fast-growing country of young people to a slow-growing, older nation.

Many Americans might consider slow growth a blessing. Your city could already be packed to the gills, the roads clogged with traffic and housing prices shooting through the roof. Why do we need more folks? And, anyway, aren’t we supposed to be conserving resources on a planet whose climate is changing? Yet demographic stagnation could bring its own high costs, among them a steady reduction in dynamism, productivity and a slowdown in national and individual prosperity, even a diminishment of global power.

And there is no real reason we have to endure such a transition, not even an environmental one. Even if your own city is packed like tinned fish, the U.S. overall can accommodate millions more people. Most of the counties in the U.S. are losing working-age adults; if these declines persist, local economies will falter, tax bases will dry up, and localgovernments will struggle to maintain services. Growth is not just an option but a necessity — it’s not just that we can afford to have more people, it may be that we can’t afford not to.

But how does a country get more people? There are two ways: Make them, and invite them in. Increasing the first is relatively difficult — birthrates are declining across the world, and while family-friendly policies may be beneficial for many reasons, they seem to do little to get people to have more babies. On the second method, though, the United States enjoys a significant advantage — people around the globe have long been clamoring to live here, notwithstanding our government’s recent hostility to foreigners. This fact presents a relatively simple policy solution to a vexing long-term issue: America needs more people, and the world has people to send us. All we have to do is let more of them in.

For decades, the United States has enjoyed a significant economic advantage over other industrialized nations — our population was growing faster, which suggested a more youthful and more prosperous future. But in the last decade, American fertility has gone down. At the same time, there has been a slowdown in immigration.

The Census Bureau’s latest numbers show that these trends are catching up with us. As of April 1, it reports that there were 331,449,281 residents in the United States, an increase of just 7.4 percent since 2010 — the second-smallest decade-long growth rate ever recorded, only slightly ahead of the 7.3 percent growth during the Depression-struck 1930s.

The bureau projects that sometime next decade — that is, in the 2030s — Americans over 65 will outnumber Americans younger than 18 for the first time in our history. The nation will cross the 400-million population mark sometime in the late 2050s, but by then we’ll be quite long in the tooth — about half of Americans will be over 45, and one fifth will be older than 85.

The idea that more people will lead to greater prosperity may sound counterintuitive — wouldn’t more people just consume more of our scarce resources? Human history generally refutes this simple intuition. Because more people usually make for more workers, more companies, and most fundamentally, more new ideas for pushing humanity forward, economic studies suggest that population growth is often an important catalyst of economic growth.

A declining global population might be beneficial in some ways; fewer people would most likely mean less carbon emission, for example — though less than you might think, since leading climate models already assume slowing population growth over the coming century. And a declining population could be catastrophic in other ways. In a recent paper, Chad Jones, an economist at Stanford, argues that a global population decline could reduce the fundamental innovativeness of humankind. The theory issimple: Without enough people, the font of new ideas dries up, Jones argues; without new ideas, progress could be imperiled.

There are more direct ways that slow growth can hurt us. As a country’s population grows heavy with retiring older people and light with working younger people, you get a problem of too many eaters and too few cooks. Programs for seniors like Social Security and Medicare may suffer as they become dependent on ever-fewer working taxpayers for funding. Another problem is the lack of people to do all the work. For instance, experts predict a major shortage of health care workers, especially home care workers, who will be needed to help the aging nation.

In a recent report, Ali Noorani, the chief executive of the National Immigration Forum, an immigration-advocacy group, and a co-author, Danilo Zak, say that increasing legal immigration by slightly more than a third each year would keep America’s ratio of working young people to retired old people stable over the next four decades.

As an immigrant myself, I have to confess I find much of the demographic argument in favor of greater immigration quite a bit too anodyne. Immigrants bring a lot more to the United States than simply working-age bodies for toiling in pursuit of greater economic growth. I also believe that the United States’ founding idea of universal equality will never be fully realized until we recognize that people outside our borders are as worthy of our ideals as those here through an accident of birth.

T E X T

Can you learn in your sleep?

Sleep is known to be crucial for learning and memory formation. What's more, scientists have even managed to pick out specific memories and consolidate them during sleep. However, the exact mechanisms behind this were unknown — until now.

Those among us who grew up with the popular cartoon "Dexter's Laboratory" might remember the famous episode wherein Dexter's trying to learn French overnight. He creates a device that helps him to learn in his sleep by playing French phrases to him. Of course, since the show is a comedy, Dexter's record gets stuck on the phrase "Omelette du fromage" and the next day he's incapable of saying anything else. This is, of course, a problem that puts him through a series of hilarious situations.

The idea that we can learn in our sleep has captivated the minds of artists and scientists alike; the possibility that one day we could all drastically improve our productivity by learning in our sleep is very appealing. But could such a scenario ever become a reality?

New research seems to suggest so, and scientists in general are moving closer to understanding precisely what goes on in the brain when we sleep and how the restful state affects learning and memory formation.

For instance, previous studies have shown that non-rapid eye movement (non-REM) sleep — or dreamless sleep — is crucial for consolidating memories. It has also been shown that sleep spindles, or sudden spikes in oscillatory brain activity that canbe seen on an electroencephalogram (EEG) during the second stage of non-REM sleep, are key for this memory consolidation. Scientists were also able to specifically target certain memories and reactivate, or strengthen, them by using auditory cues.

However, the mechanism behind such achievements remained mysterious until now. Researchers were also unaware if such mechanisms would help with memorizing new information.

Therefore, a team of researchers set out to investigate. Scott Cairney, from the University of York in the United Kingdom, co-led the research with Bernhard Staresina, who works at the University of Birmingham, also in the U.K. Their findings were published in the journal Current Biology.

Cairney explains the motivation for the research, saying, "We are quite certain that memories are reactivated in the brain during sleep, but we don't know the neural processes that underpin this phenomenon." "Sleep spindles," he continues, "have been linked to the benefits of sleep for memory in previous research, so we wanted to investigate whether these brain waves mediate reactivation. If they support memory reactivation, we further reasoned that it could be possible to decipher memory signals at the time that these spindles took place."

To test their hypotheses, Cairney and his colleagues asked 46 participants "to learn associations between words and pictures of objects or scenes before a nap." Afterward, some of the participants took a 90-minute nap, whereas others stayed awake. To those who napped, "Half of the words were [...] replayed during the nap to trigger the reactivation of the newly learned picture memories," explains Cairney.

"When the participants woke after a good period of sleep," he says, "we presented them again with the words and asked them to recall the object and scene pictures. We found that their memory was better for the pictures that were connected to the words that were presented in sleep, compared to those words that weren't," Cairney reports.

Using an EEG machine, the researchers were also able to see that playing the associated words to reactivate memories triggered sleep spindles in the participants' brains. More specifically, the EEG sleep spindle patterns "told" the researchers whether the participants were processing memories related to objects or memories related to scenes.

"Our data suggest that spindles facilitate processing of relevant memory features during sleep and that this process boosts memory consolidation," says Staresina. "While it has been shown previously," he continues, "that targeted memory reactivation can boost memory consolidation during sleep, we now show that sleep spindles might represent the key underlying mechanism."

Cairney adds, "When you are awake you learn new things, but when you are asleep you refine them, making it easier to retrieve them and apply them correctly when you need them the most. This is important for how we learn but also for how we might help retain healthy brain functions."

Staresina suggests that this newly gained knowledge could lead to effective strategies for boosting memory while sleeping.

So, though learning things from scratch à la "Dexter's Lab" may take a while to become a reality, we can safely say that our brains continue to learn while we sleep, and that researchers just got a lot closer to understanding why this happens.

From: https://www.medicalnewstoday.com/articles/Mar/2018

T E X T

Can you learn in your sleep?

Sleep is known to be crucial for learning and memory formation. What's more, scientists have even managed to pick out specific memories and consolidate them during sleep. However, the exact mechanisms behind this were unknown — until now.

Those among us who grew up with the popular cartoon "Dexter's Laboratory" might remember the famous episode wherein Dexter's trying to learn French overnight. He creates a device that helps him to learn in his sleep by playing French phrases to him. Of course, since the show is a comedy, Dexter's record gets stuck on the phrase "Omelette du fromage" and the next day he's incapable of saying anything else. This is, of course, a problem that puts him through a series of hilarious situations.

The idea that we can learn in our sleep has captivated the minds of artists and scientists alike; the possibility that one day we could all drastically improve our productivity by learning in our sleep is very appealing. But could such a scenario ever become a reality?

New research seems to suggest so, and scientists in general are moving closer to understanding precisely what goes on in the brain when we sleep and how the restful state affects learning and memory formation.

For instance, previous studies have shown that non-rapid eye movement (non-REM) sleep — or dreamless sleep — is crucial for consolidating memories. It has also been shown that sleep spindles, or sudden spikes in oscillatory brain activity that canbe seen on an electroencephalogram (EEG) during the second stage of non-REM sleep, are key for this memory consolidation. Scientists were also able to specifically target certain memories and reactivate, or strengthen, them by using auditory cues.

However, the mechanism behind such achievements remained mysterious until now. Researchers were also unaware if such mechanisms would help with memorizing new information.

Therefore, a team of researchers set out to investigate. Scott Cairney, from the University of York in the United Kingdom, co-led the research with Bernhard Staresina, who works at the University of Birmingham, also in the U.K. Their findings were published in the journal Current Biology.

Cairney explains the motivation for the research, saying, "We are quite certain that memories are reactivated in the brain during sleep, but we don't know the neural processes that underpin this phenomenon." "Sleep spindles," he continues, "have been linked to the benefits of sleep for memory in previous research, so we wanted to investigate whether these brain waves mediate reactivation. If they support memory reactivation, we further reasoned that it could be possible to decipher memory signals at the time that these spindles took place."

To test their hypotheses, Cairney and his colleagues asked 46 participants "to learn associations between words and pictures of objects or scenes before a nap." Afterward, some of the participants took a 90-minute nap, whereas others stayed awake. To those who napped, "Half of the words were [...] replayed during the nap to trigger the reactivation of the newly learned picture memories," explains Cairney.

"When the participants woke after a good period of sleep," he says, "we presented them again with the words and asked them to recall the object and scene pictures. We found that their memory was better for the pictures that were connected to the words that were presented in sleep, compared to those words that weren't," Cairney reports.

Using an EEG machine, the researchers were also able to see that playing the associated words to reactivate memories triggered sleep spindles in the participants' brains. More specifically, the EEG sleep spindle patterns "told" the researchers whether the participants were processing memories related to objects or memories related to scenes.

"Our data suggest that spindles facilitate processing of relevant memory features during sleep and that this process boosts memory consolidation," says Staresina. "While it has been shown previously," he continues, "that targeted memory reactivation can boost memory consolidation during sleep, we now show that sleep spindles might represent the key underlying mechanism."

Cairney adds, "When you are awake you learn new things, but when you are asleep you refine them, making it easier to retrieve them and apply them correctly when you need them the most. This is important for how we learn but also for how we might help retain healthy brain functions."

Staresina suggests that this newly gained knowledge could lead to effective strategies for boosting memory while sleeping.

So, though learning things from scratch à la "Dexter's Lab" may take a while to become a reality, we can safely say that our brains continue to learn while we sleep, and that researchers just got a lot closer to understanding why this happens.

From: https://www.medicalnewstoday.com/articles/Mar/2018