Questõesde UECE 2018
Para fazer o transporte de peixes de um
açude, um caminhão transporta um depósito cúbico
de aresta A com água até sua metade em uma
estrada plana horizontal ao longo de um
comprimento de 10 km. A velocidade do caminhão é
constante. O desnível θ da superfície da água no
depósito em relação à superfície da estrada é tal que
Um fio de comprimento L, preso no teto, tem
na sua outra extremidade uma massa m que
constitui um pêndulo simples que oscila com período T . As partículas ao longo do fio têm
Considerando que, em um espelho plano
incide um raio de luz, é correto afirmar que
Um gás ideal tem seu estado termodinâmico
completamente determinado pelas variáveis
Um gás ideal, em um recipiente, é mantido
em temperatura constante e em equilíbrio térmico
com a vizinhança. Nesse gás, o produto da pressão
pelo volume é
Em um sistema oscilante, a corrente elétrica
é descrita por x = a ⋅ cos (b ⋅ t). As unidades de
medida das constantes a e b são, respectivamente,
Considere um trecho de estrada em descida
seguido por uma subida. De modo simplificado,
considere que esse trecho tem um formato de arco
de círculo. Tratando um carro que passa por esse
trecho como uma massa puntiforme, é correto
afirmar que o vetor força normal da estrada sobre o
carro
A pressão hidrostática na base de uma coluna
de líquido é
proporcional à razão
proporcional à razão
Um sistema de massa constante, constituído
por um gás ideal, está no estado inicial de
volume V0 , pressão P0 e temperatura T0 . Quando o
sistema evolui para um novo estado de volume V0/2 e
pressão P0/2 , sua temperatura é
Um sistema de massa constante, constituído por um gás ideal, está no estado inicial de volume V0 , pressão P0 e temperatura T0 . Quando o sistema evolui para um novo estado de volume V0/2 e pressão P0/2 , sua temperatura é
Considere a energia potencial gravitacional de
uma massa puntiforme próxima à superfície da
Terra. Suponha que a unidade de medida de
comprimento no Sistema Internacional de Unidades
fosse mudada para o centímetro. O valor numérico
da energia potencial gravitacional, no sistema que
usa centímetros, seria igual à do sistema original
multiplicada por um fator de
Em um relógio mecânico, os ponteiros de
minuto e segundo têm velocidade angular,
respectivamente,
Recentemente os noticiários reportaram um
caso de resgate de pessoas em uma caverna
alagada. Um mergulhador submerso, durante o
trajeto até o ponto de resgate, sofre uma pressão
hidrostática devido à coluna d’água sobre ele.
Tratando-o como puntiforme, essa pressão é dada
pelo produto da
A mecânica newtoniana não é válida para
descrever fenômenos que envolvam
Atualmente é bem difundido um exame de
tomografia conhecido por PET-CT (acrônimo para
Positron Emission Tomography with Computed
Tomography). Nesse exame o paciente tem injetado
em sua corrente sanguínea uma substância que
emite radiação, especificamente na forma de
pósitrons, que são detectados por componentes do
tomógrafo. Os pósitrons têm a mesma massa do
No contexto da mecânica newtoniana, diz-se
que uma massa puntiforme está em equilíbrio
quando a soma
Scott Cairney, one of the researchers
responsible for the study, explains that the results are
relevant to understand
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 can be 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
Another finding of the research is related to the
electroencephalogram (EEG) that was done while the
participants were sleeping and exposed to the replay
of the words, which revealed
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 can be 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
As to the results of the research, the
participants who took a nap
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 can be 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
The new investigation was led by researchers
working at
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 can be 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