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Página 35 de 2.904

  • Matemática

    Matemática

    Para a instalação de uma piscina infantil em forma de cilindro reto, foi escavado no solo um buraco cilíndrico, com 4 m de diâmetro e 80 cm de altura. Antes de instalar a piscina, toda a superfície do buraco será revestida com uma manta impermeabilizante. Quantos metros quadrados de manta impermeabilizante são necessários para realizar o revestimento? Indique o valor inteiro mais próximo do valor obtido, em m².

    Dado: use a aproximação π ≃ 3,14.
    Escolha uma alternativa para a questão 03128511-d5
  • Linguagens

    Inglês

    T E X T


    Social Media Use Is Linked to Brain Changes in Teens, Research Finds




        The effect of social media use on children is a fraught area of research, as parents and policymakers try to ascertain the results of a vast experiment already in full swing. Successive studies have added pieces to the pu    zzle, fleshing out the implications of a nearly constant stream of virtual interactions beginning in childhood.

        A new study by neuroscientists at the University of North Carolina tries something new, conducting successive brain scans of middle schoolers between the ages of 12 and 15, a period of especially rapid brain development. 

        The researchers found that children who habitually checked their social media feeds at around age 12 showed a distinct trajectory, with their sensitivity to social rewards from peers heightening over time. Teenagers with less engagement in social media followed the opposite path, with a declining interest in social rewards.

        The study has important limitations, the authors acknowledge. Because adolescence is a period of expanding social relationships, the brain differences could reflect a natural pivot toward peers, which could be driving more frequent social media use.

        “We can’t make causal claims that social media is changing the brain,” said Eva H. Telzer, an associate professor of psychology and neuroscience at the University of North Carolina, Chapel Hill, and one of the authors of the study.

        But, she added, “teens who are habitually checking their social media are showing these pretty dramatic changes in the way their brains are responding, which could potentially have long-term consequences well into adulthood, sort of setting the stage for brain development over time.”

        A team of researchers studied an ethnically diverse group of 169 students in the sixth and seventh grades from a middle school in rural North Carolina, splitting them into groups according to how often they reported checking Facebook, Instagram and Snapchat feeds.

        At around age 12, the students already showed distinct patterns of behavior. Habitual users reported checking their feeds 15 or more times a day; moderate users checked between one and 14 times; nonhabitual users checked less than once a day.

        The subjects received full brain scans three times, at approximately one-year intervals, as they played a computerized game that delivered rewards and punishment in the form of smiling or scowling peers. While carrying out the task, the frequent checkers showed increasing activation of three brain areas: reward-processing circuits, which also respond to experiences like winning money or risk-taking behavior; brain regions that determine salience, picking out what stands out in the environment; and the prefrontal cortex, which helps with regulation and control.

        The results showed that “teens who grow up checking social media more often are becoming hypersensitive to feedback from their peers,” Dr. Telzer said. Social sensitivity could be adaptive, showing that the teenagers are learning to connect with others; or it could lead to social anxiety and depression if social needs are not met.

        “They are showing that the way you use it at one point in your life does influence the way your brain develops, but we don’t know by how much, or whether it’s good or bad,” said Jeff Hancock, the founding director of the Stanford Social Media Lab, who was not involved in the study. He said that many other variables could have contributed to these changes. He described the paper as “a very sophisticated piece of work,” contributing to research that has emerged recently showing that sensitivity to social media varies from person to person.

        Over the last decade, social media has remapped the central experiences of adolescence, a period of rapid brain development. Researchers have documented a range of effects on children’s mental health. Some studies have linked use of social media with depression and anxiety, while others found little connection.

        Without more information about other aspects of the students’ lives, “it is challenging to discern how specific differences in brain development are to social media checking,” said Adriana Galvan, a specialist in adolescent brain development at the University of California Los Angeles, who was not involved in the study.

        Dr. Telzer, one of the study’s authors, described the rising sensitivity to social feedback as “neither good nor bad.” “It’s helping them connect to others and obtain rewards from the things that are common in their social world, which is engaging in social interactions online,” she said. This is the new norm,” she added. “Understanding how this new digital world is influencing teens is important. It may be associated with changes in the brain, but that may be for good or for bad. We don’t necessarily know the long-term implications yet.” 


     Adapted from: https://www.nytimes.com/2023/01/03/

     

    Although this new study has found some important aspects, it
    Escolha uma alternativa para a questão 0312a03e-03
  • Linguagens

    Português

        TEXTO 1


    Português, a língua mais difícil do mundo? 

    Conta outra! . Alguns mitos resistentes rondam como mosquitos chatos a língua portuguesa falada no Brasil. Diante deles, argumentações fundadas em fatos e um mínimo de racionalidade são tão inúteis quanto tapas desferidos às cegas no escuro do quarto em pernilongos zumbidores. Os tapas acertam o vazio, os zumbidos continuam lá.

    A lenda de que se fala no estado do Maranhão o português mais “correto” do Brasil é uma dessas balelas aceitas por aí como verdades reveladas – e nem os tristíssimos índices educacionais maranhenses podem fazer nada contra isso. Tapas no vazio.

    Outra bobagem de grande prestígio é aquela que sustenta ser o português “a língua mais difícil do mundo”. Baseada, talvez, na dor de cabeça real que acomete estrangeiros confrontados com a arquitetura barroca de nossos verbos, a afirmação é categórica o bastante para dispensar a necessidade de uma prova.

    O sujeito erra o gênero da palavra alface e pronto, lá vem a desculpa universal: “Ah, também, como é difícil a porcaria dessa língua! Ah, se tivéssemos sido colonizados pelos holandeses!” Não, claro que isso não quer dizer que o queixoso saiba falar holandês. É justamente na imensa parcela monoglota da população que a crença na dificuldade insuperável da língua portuguesa encontra solo mais fértil.

    Não é uma conclusão a que se chegue depois de estudar judiciosamente latim, alemão, húngaro, russo e japonês. Ninguém precisa ter encarado um idioma em que se use declinação – vespeiro do qual a gramática portuguesa nos poupou – para sair deplorando em altos brados o desafio invencível da crase. Não há dúvida de que o mito das agruras superlativas do português diz muito sobre a falência educacional brasileira, cupim que rói as fundações de qualquer projeto de desenvolvimento social que vá além da promoção de um maior acesso da população a shopping centers.

    Temo, porém, que suas raízes sejam mais profundas. Percebe-se aí uma mistura tóxica de autocomplacência, autodepreciação, ufanismo, fuga da realidade e desculpa esfarrapada que pode ser ainda mais difícil de derrotar do que nosso vicejante semianalfabetismo.

    http://veja.abril.com.br/blog/sobre-palavras/cronica/portugues-a-lingua-mais-dificil-do-mundo-conta-outra/ 
    Ainda em consideração ao sentido de algumas palavras do Texto 1, assinale a alternativa em que o sentido de palavras ou expressões grifadas está indicado corretamente.
    Escolha uma alternativa para a questão 0314dd85-de
  • Matemática

    Matemática

    A artista e ativista indígena Kaya Agari dedica-se à pintura em diversos formatos, inspirada nos grafismos e na cultura de seu povo. Os Kurâ-Bakairi ou Kurâ (palavra da língua bakairi que pode ser traduzida como “nossa gente”) produzem pinturas corporais e estampas geométricas que simbolizam papéis sociais e elementos de sua cosmovisão. Na imagem a seguir vemos Kaya Agari produzindo um painel com a pintura chamada Kalamigari, pintura de “menina moça”. 


    Imagem da questão de Matemática, UNICAMP 2025, Aritmética e Problemas

    (Disponível em https://capiremov.org/cultura/kaya-agari-grafismo-indigena-kura-bakairi/. Acesso em 19/08/2024.)


    O painel, ao ser finalizado, será composto de 80 quadrados. Cada quadrado tem 40 cm de lado e é pintado metade em preto e metade em branco, em formato de triângulos, como mostra a imagem. Se considerarmos que cada litro da tinta preta cobre 5 m2 , para pintar o painel será necessário
    Escolha uma alternativa para a questão 031537c2-d7
  • Matemática

    Matemática

    O custo total do dia de trabalho de uma empresa pode ser descrito pela expressão C(x) = 3x²+ 11x, em que x representa a quantidade de clientes atendidos. O valor recebido pela empresa em um dia pode ser descrito pela igualdade V(x) = 83x. O lucro diário da empresa é dado por L(x) = V(x) – C(x).

    Para que o lucro seja máximo em um dia, quantos clientes devem ser atendidos?
    Escolha uma alternativa para a questão 03155f65-d5
  • Linguagens

    Inglês

    T E X T


    Social Media Use Is Linked to Brain Changes in Teens, Research Finds




        The effect of social media use on children is a fraught area of research, as parents and policymakers try to ascertain the results of a vast experiment already in full swing. Successive studies have added pieces to the pu    zzle, fleshing out the implications of a nearly constant stream of virtual interactions beginning in childhood.

        A new study by neuroscientists at the University of North Carolina tries something new, conducting successive brain scans of middle schoolers between the ages of 12 and 15, a period of especially rapid brain development. 

        The researchers found that children who habitually checked their social media feeds at around age 12 showed a distinct trajectory, with their sensitivity to social rewards from peers heightening over time. Teenagers with less engagement in social media followed the opposite path, with a declining interest in social rewards.

        The study has important limitations, the authors acknowledge. Because adolescence is a period of expanding social relationships, the brain differences could reflect a natural pivot toward peers, which could be driving more frequent social media use.

        “We can’t make causal claims that social media is changing the brain,” said Eva H. Telzer, an associate professor of psychology and neuroscience at the University of North Carolina, Chapel Hill, and one of the authors of the study.

        But, she added, “teens who are habitually checking their social media are showing these pretty dramatic changes in the way their brains are responding, which could potentially have long-term consequences well into adulthood, sort of setting the stage for brain development over time.”

        A team of researchers studied an ethnically diverse group of 169 students in the sixth and seventh grades from a middle school in rural North Carolina, splitting them into groups according to how often they reported checking Facebook, Instagram and Snapchat feeds.

        At around age 12, the students already showed distinct patterns of behavior. Habitual users reported checking their feeds 15 or more times a day; moderate users checked between one and 14 times; nonhabitual users checked less than once a day.

        The subjects received full brain scans three times, at approximately one-year intervals, as they played a computerized game that delivered rewards and punishment in the form of smiling or scowling peers. While carrying out the task, the frequent checkers showed increasing activation of three brain areas: reward-processing circuits, which also respond to experiences like winning money or risk-taking behavior; brain regions that determine salience, picking out what stands out in the environment; and the prefrontal cortex, which helps with regulation and control.

        The results showed that “teens who grow up checking social media more often are becoming hypersensitive to feedback from their peers,” Dr. Telzer said. Social sensitivity could be adaptive, showing that the teenagers are learning to connect with others; or it could lead to social anxiety and depression if social needs are not met.

        “They are showing that the way you use it at one point in your life does influence the way your brain develops, but we don’t know by how much, or whether it’s good or bad,” said Jeff Hancock, the founding director of the Stanford Social Media Lab, who was not involved in the study. He said that many other variables could have contributed to these changes. He described the paper as “a very sophisticated piece of work,” contributing to research that has emerged recently showing that sensitivity to social media varies from person to person.

        Over the last decade, social media has remapped the central experiences of adolescence, a period of rapid brain development. Researchers have documented a range of effects on children’s mental health. Some studies have linked use of social media with depression and anxiety, while others found little connection.

        Without more information about other aspects of the students’ lives, “it is challenging to discern how specific differences in brain development are to social media checking,” said Adriana Galvan, a specialist in adolescent brain development at the University of California Los Angeles, who was not involved in the study.

        Dr. Telzer, one of the study’s authors, described the rising sensitivity to social feedback as “neither good nor bad.” “It’s helping them connect to others and obtain rewards from the things that are common in their social world, which is engaging in social interactions online,” she said. This is the new norm,” she added. “Understanding how this new digital world is influencing teens is important. It may be associated with changes in the brain, but that may be for good or for bad. We don’t necessarily know the long-term implications yet.” 


     Adapted from: https://www.nytimes.com/2023/01/03/

     

    Regarding social sensitivity, Dr. Eva H. Telzer points out that some of the negative consequences might be
    Escolha uma alternativa para a questão 03156460-03
  • Ciências da Natureza

    Química

    Os íons Ca+2 e Pb+2 possuem
    (Dados: Número atômico: Ca = 20 ; Pb = 82)
    Escolha uma alternativa para a questão 0316eba4-b0
  • Matemática

    Matemática

    Uma pesquisa de mercado sobre produtos de limpeza fez uma comparação entre duas marcas de produto. Todos eles são concentrados e, para o uso, é necessário fazer uma diluição em água. A tabela a seguir apresenta essa comparação em relação ao preço e ao rendimento de cada produto por litro. 


    Imagem da questão de Matemática, UNICAMP 2025, Análise de Tabelas e Gráficos


    Um consumidor pretende comprar um litro de cada produto escolhendo a marca que apresenta menor custo em relação ao rendimento, isto é, a quantidade do produto após diluição.


    Considerando a opção mais econômica de sabão líquido, amaciante e detergente, o consumidor escolheu respectivamente os produtos das marcas:
    Escolha uma alternativa para a questão 0317dbcd-d7
  • Linguagens

    Inglês

    T E X T


    Social Media Use Is Linked to Brain Changes in Teens, Research Finds




        The effect of social media use on children is a fraught area of research, as parents and policymakers try to ascertain the results of a vast experiment already in full swing. Successive studies have added pieces to the pu    zzle, fleshing out the implications of a nearly constant stream of virtual interactions beginning in childhood.

        A new study by neuroscientists at the University of North Carolina tries something new, conducting successive brain scans of middle schoolers between the ages of 12 and 15, a period of especially rapid brain development. 

        The researchers found that children who habitually checked their social media feeds at around age 12 showed a distinct trajectory, with their sensitivity to social rewards from peers heightening over time. Teenagers with less engagement in social media followed the opposite path, with a declining interest in social rewards.

        The study has important limitations, the authors acknowledge. Because adolescence is a period of expanding social relationships, the brain differences could reflect a natural pivot toward peers, which could be driving more frequent social media use.

        “We can’t make causal claims that social media is changing the brain,” said Eva H. Telzer, an associate professor of psychology and neuroscience at the University of North Carolina, Chapel Hill, and one of the authors of the study.

        But, she added, “teens who are habitually checking their social media are showing these pretty dramatic changes in the way their brains are responding, which could potentially have long-term consequences well into adulthood, sort of setting the stage for brain development over time.”

        A team of researchers studied an ethnically diverse group of 169 students in the sixth and seventh grades from a middle school in rural North Carolina, splitting them into groups according to how often they reported checking Facebook, Instagram and Snapchat feeds.

        At around age 12, the students already showed distinct patterns of behavior. Habitual users reported checking their feeds 15 or more times a day; moderate users checked between one and 14 times; nonhabitual users checked less than once a day.

        The subjects received full brain scans three times, at approximately one-year intervals, as they played a computerized game that delivered rewards and punishment in the form of smiling or scowling peers. While carrying out the task, the frequent checkers showed increasing activation of three brain areas: reward-processing circuits, which also respond to experiences like winning money or risk-taking behavior; brain regions that determine salience, picking out what stands out in the environment; and the prefrontal cortex, which helps with regulation and control.

        The results showed that “teens who grow up checking social media more often are becoming hypersensitive to feedback from their peers,” Dr. Telzer said. Social sensitivity could be adaptive, showing that the teenagers are learning to connect with others; or it could lead to social anxiety and depression if social needs are not met.

        “They are showing that the way you use it at one point in your life does influence the way your brain develops, but we don’t know by how much, or whether it’s good or bad,” said Jeff Hancock, the founding director of the Stanford Social Media Lab, who was not involved in the study. He said that many other variables could have contributed to these changes. He described the paper as “a very sophisticated piece of work,” contributing to research that has emerged recently showing that sensitivity to social media varies from person to person.

        Over the last decade, social media has remapped the central experiences of adolescence, a period of rapid brain development. Researchers have documented a range of effects on children’s mental health. Some studies have linked use of social media with depression and anxiety, while others found little connection.

        Without more information about other aspects of the students’ lives, “it is challenging to discern how specific differences in brain development are to social media checking,” said Adriana Galvan, a specialist in adolescent brain development at the University of California Los Angeles, who was not involved in the study.

        Dr. Telzer, one of the study’s authors, described the rising sensitivity to social feedback as “neither good nor bad.” “It’s helping them connect to others and obtain rewards from the things that are common in their social world, which is engaging in social interactions online,” she said. This is the new norm,” she added. “Understanding how this new digital world is influencing teens is important. It may be associated with changes in the brain, but that may be for good or for bad. We don’t necessarily know the long-term implications yet.” 


     Adapted from: https://www.nytimes.com/2023/01/03/

     

    Jeff Hancock, from the Stanford Social Media Lab, believes that using social media
    Escolha uma alternativa para a questão 0317e975-03
  • Matemática

    Matemática

    Marcos precisa de uma nova senha para o seu e-mail. O provedor exige que a senha possua letras e números. Assim, Marcos decidiu usar todas as letras do seu nome e todos os dígitos do seu ano de nascimento. Sabendo que Marcos nasceu em 1956 e que deixará os algarismos para o final da senha, quantas possibilidades de senha ele terá para escolher?
    Escolha uma alternativa para a questão 03187179-d5
  • Linguagens

    Português

    Considerando as normas do português contemporâneo, quanto à concordância e a regência verbal, a alternativa que se conforma à norma-padrão é:
    Escolha uma alternativa para a questão 0319598b-de
  • “Os brancos se dizem inteligentes. Não o somos menos. Nossos pensamentos se expandem em todas as direções e nossas palavras são antigas e muitas. Elas vêm de nossos antepassados. Porém, não precisamos, como os brancos, de peles de imagens para impedi-las de fugir da nossa mente. Não temos de desenhá-las, como eles fazem com as suas. Nem por isso elas irão desaparecer, pois ficam gravadas dentro de nós. Por isso nossa memória é longa e forte. O mesmo ocorre com as palavras dos espíritos xapiri, que também são muito antigas. Mas voltam a ser novas sempre que eles vêm de novo dançar para um jovem xamã, e assim tem sido há muito tempo, sem fim.”


    (KOPENAWA, Davi. A queda do céu: palavras de um xamã yanomami. Coautoria de Bruce Albert. Tradução de Beatriz Perrone-Moisés. São Paulo, SP: Companhia das Letras, 2015. P. 75.)


    De acordo com o texto, é correto afirmar sobre os yanomamis que
    Escolha uma alternativa para a questão 031a5df4-d7
  • Linguagens

    Inglês

    T E X T


    Social Media Use Is Linked to Brain Changes in Teens, Research Finds




        The effect of social media use on children is a fraught area of research, as parents and policymakers try to ascertain the results of a vast experiment already in full swing. Successive studies have added pieces to the pu    zzle, fleshing out the implications of a nearly constant stream of virtual interactions beginning in childhood.

        A new study by neuroscientists at the University of North Carolina tries something new, conducting successive brain scans of middle schoolers between the ages of 12 and 15, a period of especially rapid brain development. 

        The researchers found that children who habitually checked their social media feeds at around age 12 showed a distinct trajectory, with their sensitivity to social rewards from peers heightening over time. Teenagers with less engagement in social media followed the opposite path, with a declining interest in social rewards.

        The study has important limitations, the authors acknowledge. Because adolescence is a period of expanding social relationships, the brain differences could reflect a natural pivot toward peers, which could be driving more frequent social media use.

        “We can’t make causal claims that social media is changing the brain,” said Eva H. Telzer, an associate professor of psychology and neuroscience at the University of North Carolina, Chapel Hill, and one of the authors of the study.

        But, she added, “teens who are habitually checking their social media are showing these pretty dramatic changes in the way their brains are responding, which could potentially have long-term consequences well into adulthood, sort of setting the stage for brain development over time.”

        A team of researchers studied an ethnically diverse group of 169 students in the sixth and seventh grades from a middle school in rural North Carolina, splitting them into groups according to how often they reported checking Facebook, Instagram and Snapchat feeds.

        At around age 12, the students already showed distinct patterns of behavior. Habitual users reported checking their feeds 15 or more times a day; moderate users checked between one and 14 times; nonhabitual users checked less than once a day.

        The subjects received full brain scans three times, at approximately one-year intervals, as they played a computerized game that delivered rewards and punishment in the form of smiling or scowling peers. While carrying out the task, the frequent checkers showed increasing activation of three brain areas: reward-processing circuits, which also respond to experiences like winning money or risk-taking behavior; brain regions that determine salience, picking out what stands out in the environment; and the prefrontal cortex, which helps with regulation and control.

        The results showed that “teens who grow up checking social media more often are becoming hypersensitive to feedback from their peers,” Dr. Telzer said. Social sensitivity could be adaptive, showing that the teenagers are learning to connect with others; or it could lead to social anxiety and depression if social needs are not met.

        “They are showing that the way you use it at one point in your life does influence the way your brain develops, but we don’t know by how much, or whether it’s good or bad,” said Jeff Hancock, the founding director of the Stanford Social Media Lab, who was not involved in the study. He said that many other variables could have contributed to these changes. He described the paper as “a very sophisticated piece of work,” contributing to research that has emerged recently showing that sensitivity to social media varies from person to person.

        Over the last decade, social media has remapped the central experiences of adolescence, a period of rapid brain development. Researchers have documented a range of effects on children’s mental health. Some studies have linked use of social media with depression and anxiety, while others found little connection.

        Without more information about other aspects of the students’ lives, “it is challenging to discern how specific differences in brain development are to social media checking,” said Adriana Galvan, a specialist in adolescent brain development at the University of California Los Angeles, who was not involved in the study.

        Dr. Telzer, one of the study’s authors, described the rising sensitivity to social feedback as “neither good nor bad.” “It’s helping them connect to others and obtain rewards from the things that are common in their social world, which is engaging in social interactions online,” she said. This is the new norm,” she added. “Understanding how this new digital world is influencing teens is important. It may be associated with changes in the brain, but that may be for good or for bad. We don’t necessarily know the long-term implications yet.” 


     Adapted from: https://www.nytimes.com/2023/01/03/

     

    In the study involving 169 North Carolina school students who had brain scans 3 times, the teens who check social media frequently showed a/an
    Escolha uma alternativa para a questão 031a6321-03
  • Ciências Humanas

    Geografia

    Observando a pirâmide da população mundial e, considerando que sua elaboração se baseia em médias estatísticas, é correto afirmar que

    Imagem da questão de Geografia, UEPB 2007, Crescimento

    I. as projeções de crescimento da população idosa preocupam, sobretudo, os países ricos que começam a reformular seus sistemas de seguridade social, utilizando medidas como o aumento da idade mínima para aposentadoria e a elevação da contribuição dos trabalhadores.

    II. a pirâmide da população mundial mostra uma projeção relativamente equilibrada para 2050 entre a faixas etárias, mas não reflete o problemático antagonismo entre os dois mundos, já que faltam jovens para sustentar o crescimento do primeiro mundo e empregos para os jovens do mundo subdesenvolvido.

    III. a ilustração mostra duas pirâmides sobrepostas, uma para a população do terceiro mundo, na qual temos uma base larga e um ápice estreito, pela maior presença de jovens, e uma pirâmide para o mundo desenvolvido, que se aproxima da forma de um retângulo, por haver maior presença de adultos e idosos.

    IV. as projeções apontam para uma explosão demográfica em 2050, já que a redução da mortalidade, acompanhada do aumento da natalidade em todo o mundo, faz com que a população cresça num ritmo mais acelerado que o previsto pelos demógrafos.

    Estão corretas apenas as proposições:
    Escolha uma alternativa para a questão 031b70c1-70
  • Ciências da Natureza

    Física

    O gráfico a seguir mostra a velocidade de um objeto em função do tempo. O objeto executa um movimento retilíneo. No instante t = 2,0 s, ele se encontra na posição x = 5,0 m. Escreva a equação da posição desse objeto em função do tempo, válida no intervalo de t = 0 até t = 4,0 s. Considere a posição em metros e o tempo em segundos.

    Imagem da questão de Física, Centro de Estudos Superiores de Maceió - Centro Universitário 2017, Cinemática
    Escolha uma alternativa para a questão 031c5b7b-d5
  • Linguagens

    Inglês

    T E X T


    Social Media Use Is Linked to Brain Changes in Teens, Research Finds




        The effect of social media use on children is a fraught area of research, as parents and policymakers try to ascertain the results of a vast experiment already in full swing. Successive studies have added pieces to the pu    zzle, fleshing out the implications of a nearly constant stream of virtual interactions beginning in childhood.

        A new study by neuroscientists at the University of North Carolina tries something new, conducting successive brain scans of middle schoolers between the ages of 12 and 15, a period of especially rapid brain development. 

        The researchers found that children who habitually checked their social media feeds at around age 12 showed a distinct trajectory, with their sensitivity to social rewards from peers heightening over time. Teenagers with less engagement in social media followed the opposite path, with a declining interest in social rewards.

        The study has important limitations, the authors acknowledge. Because adolescence is a period of expanding social relationships, the brain differences could reflect a natural pivot toward peers, which could be driving more frequent social media use.

        “We can’t make causal claims that social media is changing the brain,” said Eva H. Telzer, an associate professor of psychology and neuroscience at the University of North Carolina, Chapel Hill, and one of the authors of the study.

        But, she added, “teens who are habitually checking their social media are showing these pretty dramatic changes in the way their brains are responding, which could potentially have long-term consequences well into adulthood, sort of setting the stage for brain development over time.”

        A team of researchers studied an ethnically diverse group of 169 students in the sixth and seventh grades from a middle school in rural North Carolina, splitting them into groups according to how often they reported checking Facebook, Instagram and Snapchat feeds.

        At around age 12, the students already showed distinct patterns of behavior. Habitual users reported checking their feeds 15 or more times a day; moderate users checked between one and 14 times; nonhabitual users checked less than once a day.

        The subjects received full brain scans three times, at approximately one-year intervals, as they played a computerized game that delivered rewards and punishment in the form of smiling or scowling peers. While carrying out the task, the frequent checkers showed increasing activation of three brain areas: reward-processing circuits, which also respond to experiences like winning money or risk-taking behavior; brain regions that determine salience, picking out what stands out in the environment; and the prefrontal cortex, which helps with regulation and control.

        The results showed that “teens who grow up checking social media more often are becoming hypersensitive to feedback from their peers,” Dr. Telzer said. Social sensitivity could be adaptive, showing that the teenagers are learning to connect with others; or it could lead to social anxiety and depression if social needs are not met.

        “They are showing that the way you use it at one point in your life does influence the way your brain develops, but we don’t know by how much, or whether it’s good or bad,” said Jeff Hancock, the founding director of the Stanford Social Media Lab, who was not involved in the study. He said that many other variables could have contributed to these changes. He described the paper as “a very sophisticated piece of work,” contributing to research that has emerged recently showing that sensitivity to social media varies from person to person.

        Over the last decade, social media has remapped the central experiences of adolescence, a period of rapid brain development. Researchers have documented a range of effects on children’s mental health. Some studies have linked use of social media with depression and anxiety, while others found little connection.

        Without more information about other aspects of the students’ lives, “it is challenging to discern how specific differences in brain development are to social media checking,” said Adriana Galvan, a specialist in adolescent brain development at the University of California Los Angeles, who was not involved in the study.

        Dr. Telzer, one of the study’s authors, described the rising sensitivity to social feedback as “neither good nor bad.” “It’s helping them connect to others and obtain rewards from the things that are common in their social world, which is engaging in social interactions online,” she said. This is the new norm,” she added. “Understanding how this new digital world is influencing teens is important. It may be associated with changes in the brain, but that may be for good or for bad. We don’t necessarily know the long-term implications yet.” 


     Adapted from: https://www.nytimes.com/2023/01/03/

     

    According to Dr. Telzer, engaging in social media is the new norm, but despite the many studies made in the last decade, researchers
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  • Linguagens

    Português

    TEXTO 2

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  • Ciências Humanas

    História

    Antigamente, havia muitas possibilidades de marcar o tempo espalhadas pelo mundo e muitos inventores tentaram aprimorar esses sistemas. Havia, por exemplo, a invenção de Yi Xing, um monge budista chinês que desenvolveu uma máquina que contava 24 horas a partir de um sistema de queda d’água, cordas, encanamentos, baldes e engrenagens. Os primeiros relógios de pêndulo foram construídos nas igrejas da Europa por volta dos anos 1300. Séculos depois, com a Revolução Industrial, não demorou para que nos tornássemos servos de relógios, alarmes, horários e prazos cada vez mais apertados. Os relógios se tornaram menores e portáteis. Atualmente, temos os relógios atômicos, que registram oscilações de energia em átomos de césio. Nossos celulares, aparelhos e os relógios oficiais de todo o mundo são sincronizados nesses medidores de tempo atômico.


    (Adaptado de Calendários, relógios e alguns dos inventores do tempo. Blog Espaço do Conhecimento – UFMG. Disponível em https://www.ufmg.br/espa codoconhecimento/ calendarios-relogios-e-alguns-dos-inventores-do- tempo/. Acesso em 02/12/2024.)


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