Questões: Universidade Federal de São Paulo (UNIFESP) — com gabarito

 Instrução: Leia o texto para responder às questões de números 31 a 39.

               Brazil: the natural knowledge economy
Kirsten Bound – THE ATLAS OF IDEAS

    If you grew up in Europe or North America you will no doubt have been taught in school that the Wright Brothers from Ohio invented and flew the first aeroplane – the Kitty Hawk – in 1903. But if you grew up in Brazil you will have been taught that the real inventor was in fact a Brazilian from Minas Gerais called
Alberto Santos Dumont, whose 14-bis aeroplane took to the skies in 1906. This fierce historical debate, which turns on definitions of ‘practical airplanes’, the ability to launch unaided, length of time spent in the air and the credibility of witnesses, will not be resolved here. Yet it is a striking example of the lack of global recognition for Brazil’s achievements in innovation.
    Almost a century later, in 2005, Santos Dumont’s intellectual heirs, the company Empresa Brasileira de Aeronáutica (EMBRAER), made aviation history of a different kind when they unveiled the Ipanema, the world’s first commercially produced aircraft to run solely on biofuels. This time, the world
was watching. Scientific American credited it as one of the most important inventions of the year. The attention paid to the Ipanema reflects the growing interest in biofuels as a potential solution to climate change and rising energy demand. To their advocates, biofuels – most commonly bioethanol or biodiesel – offer a more secure, sustainable energy supply that can reduce carbon emissions by 50–60 per cent compared to fossil fuels.
      From learning to fly to learning to cope with the environmental costs of flight, biofuel innovations like the Ipanema reflect some of the tensions of modern science, in which expanding the frontiers of human ingenuity goes hand in hand with managing the consequences. The recent backlash against biofuels, which has seen them blamed for global food shortages as land is reportedly diverted from food crops, points to a growing interdependence between the science and innovation systems of different countries, and between innovation, economics and environmental sustainability.
    The debates now raging over biofuels reflect some of the wider dynamics in Brazil’s innovation system. They remind us that Brazil’s current strengths and achievements have deeper historical roots than is sometimes imagined. They reflect the fact that Brazil’s natural resources and assets are a key area of opportunity for science and innovation – a focus that leads us to characterise Brazil as a ‘natural knowledge economy’. Most importantly, they highlight the propitious timing of Brazil’s growing strength in these areas at a time when climate change, the environment, food scarcity and rising worldwide energy demand are at the forefront of global consciousness. What changed between the maiden flight of the 14-bis and the maiden flight of the Ipanema is not just Brazil’s capacity for technological and scientific innovation, but the rest of the world’s appreciation of the potential of that innovation to address some of the pressing challenges that confront us all.

 Instrução: Leia o texto para responder às questões de números 31 a 39.

               Brazil: the natural knowledge economy
Kirsten Bound – THE ATLAS OF IDEAS

    If you grew up in Europe or North America you will no doubt have been taught in school that the Wright Brothers from Ohio invented and flew the first aeroplane – the Kitty Hawk – in 1903. But if you grew up in Brazil you will have been taught that the real inventor was in fact a Brazilian from Minas Gerais called
Alberto Santos Dumont, whose 14-bis aeroplane took to the skies in 1906. This fierce historical debate, which turns on definitions of ‘practical airplanes’, the ability to launch unaided, length of time spent in the air and the credibility of witnesses, will not be resolved here. Yet it is a striking example of the lack of global recognition for Brazil’s achievements in innovation.
    Almost a century later, in 2005, Santos Dumont’s intellectual heirs, the company Empresa Brasileira de Aeronáutica (EMBRAER), made aviation history of a different kind when they unveiled the Ipanema, the world’s first commercially produced aircraft to run solely on biofuels. This time, the world
was watching. Scientific American credited it as one of the most important inventions of the year. The attention paid to the Ipanema reflects the growing interest in biofuels as a potential solution to climate change and rising energy demand. To their advocates, biofuels – most commonly bioethanol or biodiesel – offer a more secure, sustainable energy supply that can reduce carbon emissions by 50–60 per cent compared to fossil fuels.
      From learning to fly to learning to cope with the environmental costs of flight, biofuel innovations like the Ipanema reflect some of the tensions of modern science, in which expanding the frontiers of human ingenuity goes hand in hand with managing the consequences. The recent backlash against biofuels, which has seen them blamed for global food shortages as land is reportedly diverted from food crops, points to a growing interdependence between the science and innovation systems of different countries, and between innovation, economics and environmental sustainability.
    The debates now raging over biofuels reflect some of the wider dynamics in Brazil’s innovation system. They remind us that Brazil’s current strengths and achievements have deeper historical roots than is sometimes imagined. They reflect the fact that Brazil’s natural resources and assets are a key area of opportunity for science and innovation – a focus that leads us to characterise Brazil as a ‘natural knowledge economy’. Most importantly, they highlight the propitious timing of Brazil’s growing strength in these areas at a time when climate change, the environment, food scarcity and rising worldwide energy demand are at the forefront of global consciousness. What changed between the maiden flight of the 14-bis and the maiden flight of the Ipanema is not just Brazil’s capacity for technological and scientific innovation, but the rest of the world’s appreciation of the potential of that innovation to address some of the pressing challenges that confront us all.

 Instrução: Leia o texto para responder às questões de números 31 a 39.

               Brazil: the natural knowledge economy
Kirsten Bound – THE ATLAS OF IDEAS

    If you grew up in Europe or North America you will no doubt have been taught in school that the Wright Brothers from Ohio invented and flew the first aeroplane – the Kitty Hawk – in 1903. But if you grew up in Brazil you will have been taught that the real inventor was in fact a Brazilian from Minas Gerais called
Alberto Santos Dumont, whose 14-bis aeroplane took to the skies in 1906. This fierce historical debate, which turns on definitions of ‘practical airplanes’, the ability to launch unaided, length of time spent in the air and the credibility of witnesses, will not be resolved here. Yet it is a striking example of the lack of global recognition for Brazil’s achievements in innovation.
    Almost a century later, in 2005, Santos Dumont’s intellectual heirs, the company Empresa Brasileira de Aeronáutica (EMBRAER), made aviation history of a different kind when they unveiled the Ipanema, the world’s first commercially produced aircraft to run solely on biofuels. This time, the world
was watching. Scientific American credited it as one of the most important inventions of the year. The attention paid to the Ipanema reflects the growing interest in biofuels as a potential solution to climate change and rising energy demand. To their advocates, biofuels – most commonly bioethanol or biodiesel – offer a more secure, sustainable energy supply that can reduce carbon emissions by 50–60 per cent compared to fossil fuels.
      From learning to fly to learning to cope with the environmental costs of flight, biofuel innovations like the Ipanema reflect some of the tensions of modern science, in which expanding the frontiers of human ingenuity goes hand in hand with managing the consequences. The recent backlash against biofuels, which has seen them blamed for global food shortages as land is reportedly diverted from food crops, points to a growing interdependence between the science and innovation systems of different countries, and between innovation, economics and environmental sustainability.
    The debates now raging over biofuels reflect some of the wider dynamics in Brazil’s innovation system. They remind us that Brazil’s current strengths and achievements have deeper historical roots than is sometimes imagined. They reflect the fact that Brazil’s natural resources and assets are a key area of opportunity for science and innovation – a focus that leads us to characterise Brazil as a ‘natural knowledge economy’. Most importantly, they highlight the propitious timing of Brazil’s growing strength in these areas at a time when climate change, the environment, food scarcity and rising worldwide energy demand are at the forefront of global consciousness. What changed between the maiden flight of the 14-bis and the maiden flight of the Ipanema is not just Brazil’s capacity for technological and scientific innovation, but the rest of the world’s appreciation of the potential of that innovation to address some of the pressing challenges that confront us all.

 Instrução: Leia o texto para responder às questões de números 31 a 39.

               Brazil: the natural knowledge economy
Kirsten Bound – THE ATLAS OF IDEAS

    If you grew up in Europe or North America you will no doubt have been taught in school that the Wright Brothers from Ohio invented and flew the first aeroplane – the Kitty Hawk – in 1903. But if you grew up in Brazil you will have been taught that the real inventor was in fact a Brazilian from Minas Gerais called
Alberto Santos Dumont, whose 14-bis aeroplane took to the skies in 1906. This fierce historical debate, which turns on definitions of ‘practical airplanes’, the ability to launch unaided, length of time spent in the air and the credibility of witnesses, will not be resolved here. Yet it is a striking example of the lack of global recognition for Brazil’s achievements in innovation.
    Almost a century later, in 2005, Santos Dumont’s intellectual heirs, the company Empresa Brasileira de Aeronáutica (EMBRAER), made aviation history of a different kind when they unveiled the Ipanema, the world’s first commercially produced aircraft to run solely on biofuels. This time, the world
was watching. Scientific American credited it as one of the most important inventions of the year. The attention paid to the Ipanema reflects the growing interest in biofuels as a potential solution to climate change and rising energy demand. To their advocates, biofuels – most commonly bioethanol or biodiesel – offer a more secure, sustainable energy supply that can reduce carbon emissions by 50–60 per cent compared to fossil fuels.
      From learning to fly to learning to cope with the environmental costs of flight, biofuel innovations like the Ipanema reflect some of the tensions of modern science, in which expanding the frontiers of human ingenuity goes hand in hand with managing the consequences. The recent backlash against biofuels, which has seen them blamed for global food shortages as land is reportedly diverted from food crops, points to a growing interdependence between the science and innovation systems of different countries, and between innovation, economics and environmental sustainability.
    The debates now raging over biofuels reflect some of the wider dynamics in Brazil’s innovation system. They remind us that Brazil’s current strengths and achievements have deeper historical roots than is sometimes imagined. They reflect the fact that Brazil’s natural resources and assets are a key area of opportunity for science and innovation – a focus that leads us to characterise Brazil as a ‘natural knowledge economy’. Most importantly, they highlight the propitious timing of Brazil’s growing strength in these areas at a time when climate change, the environment, food scarcity and rising worldwide energy demand are at the forefront of global consciousness. What changed between the maiden flight of the 14-bis and the maiden flight of the Ipanema is not just Brazil’s capacity for technological and scientific innovation, but the rest of the world’s appreciation of the potential of that innovation to address some of the pressing challenges that confront us all.

 Instrução: Leia o texto para responder às questões de números 31 a 39.

               Brazil: the natural knowledge economy
Kirsten Bound – THE ATLAS OF IDEAS

    If you grew up in Europe or North America you will no doubt have been taught in school that the Wright Brothers from Ohio invented and flew the first aeroplane – the Kitty Hawk – in 1903. But if you grew up in Brazil you will have been taught that the real inventor was in fact a Brazilian from Minas Gerais called
Alberto Santos Dumont, whose 14-bis aeroplane took to the skies in 1906. This fierce historical debate, which turns on definitions of ‘practical airplanes’, the ability to launch unaided, length of time spent in the air and the credibility of witnesses, will not be resolved here. Yet it is a striking example of the lack of global recognition for Brazil’s achievements in innovation.
    Almost a century later, in 2005, Santos Dumont’s intellectual heirs, the company Empresa Brasileira de Aeronáutica (EMBRAER), made aviation history of a different kind when they unveiled the Ipanema, the world’s first commercially produced aircraft to run solely on biofuels. This time, the world
was watching. Scientific American credited it as one of the most important inventions of the year. The attention paid to the Ipanema reflects the growing interest in biofuels as a potential solution to climate change and rising energy demand. To their advocates, biofuels – most commonly bioethanol or biodiesel – offer a more secure, sustainable energy supply that can reduce carbon emissions by 50–60 per cent compared to fossil fuels.
      From learning to fly to learning to cope with the environmental costs of flight, biofuel innovations like the Ipanema reflect some of the tensions of modern science, in which expanding the frontiers of human ingenuity goes hand in hand with managing the consequences. The recent backlash against biofuels, which has seen them blamed for global food shortages as land is reportedly diverted from food crops, points to a growing interdependence between the science and innovation systems of different countries, and between innovation, economics and environmental sustainability.
    The debates now raging over biofuels reflect some of the wider dynamics in Brazil’s innovation system. They remind us that Brazil’s current strengths and achievements have deeper historical roots than is sometimes imagined. They reflect the fact that Brazil’s natural resources and assets are a key area of opportunity for science and innovation – a focus that leads us to characterise Brazil as a ‘natural knowledge economy’. Most importantly, they highlight the propitious timing of Brazil’s growing strength in these areas at a time when climate change, the environment, food scarcity and rising worldwide energy demand are at the forefront of global consciousness. What changed between the maiden flight of the 14-bis and the maiden flight of the Ipanema is not just Brazil’s capacity for technological and scientific innovation, but the rest of the world’s appreciation of the potential of that innovation to address some of the pressing challenges that confront us all.

     So a scientist walks into a shopping mall to watch people laugh. There’s no punchline. Laughter is a serious scientific subject, one that researchers are still trying to figure out. Laughing is primal, our first way of communicating. Apes laugh. So do dogs and rats. Babies laugh long before they speak. No one teaches you how to laugh. You just do. And often you laugh involuntarily, in a specific rhythm and in certain spots in conversation.
    You may laugh at a prank on April Fools’ Day. But surprisingly,  only 10 to 15 percent of laughter is the result of someone making a joke, said Baltimore neuroscientist Robert Provine, who has studied laughter for decades. Laughter is mostly about social responses rather than reaction to a joke. “Laughter above all else is a social thing,’’ Provine said. “The requirement for laughter is another person.’’  
    Over the years, Provine, a professor with the University of Maryland Baltimore County, has boiled laughter down to its basics. “All language groups laugh ‘ha-ha-ha’ basically the same way,’’ he said. “Whether you speak Mandarin, French or English, everyone will understand laughter. ... There’s a pattern generator in our brain that produces this sound.’’
    Each “ha’’ is about one-15th of a second, repeated every fifth of a second, he said. Laugh faster or slower than that and it sounds more like panting or something else. Deaf people laugh without hearing, and people on cell phones laugh without seeing, illustrating that laughter isn’t dependent on a single sense but on social interactions, said Provine, author of the book “Laughter: A Scientific Investigation.’’   
    “It’s joy, it’s positive engagement with life,’’ said Jaak Panksepp, a Bowling Green University psychology professor. “It’s deeply social.’’ And it’s not just a people thing either. Chimps tickle each other and even laugh when another chimp pretends to tickle them. By studying rats, Panksepp and other scientists can figure out what’s going on in the brain during laughter. And it holds promise for human ills.
    Northwestern biomedical engineering professor Jeffrey Burgdorf has found that laughter in rats produces an insulin-like growth factor chemical that acts as an antidepressant and anxietyreducer. He thinks the same thing probably happens in humans, too. This would give doctors a new chemical target in the brain in their effort to develop drugs that fight depression and anxiety in people. Even so, laughter itself hasn’t been proven to be the best medicine, experts said.

     So a scientist walks into a shopping mall to watch people laugh. There’s no punchline. Laughter is a serious scientific subject, one that researchers are still trying to figure out. Laughing is primal, our first way of communicating. Apes laugh. So do dogs and rats. Babies laugh long before they speak. No one teaches you how to laugh. You just do. And often you laugh involuntarily, in a specific rhythm and in certain spots in conversation.
    You may laugh at a prank on April Fools’ Day. But surprisingly,  only 10 to 15 percent of laughter is the result of someone making a joke, said Baltimore neuroscientist Robert Provine, who has studied laughter for decades. Laughter is mostly about social responses rather than reaction to a joke. “Laughter above all else is a social thing,’’ Provine said. “The requirement for laughter is another person.’’  
    Over the years, Provine, a professor with the University of Maryland Baltimore County, has boiled laughter down to its basics. “All language groups laugh ‘ha-ha-ha’ basically the same way,’’ he said. “Whether you speak Mandarin, French or English, everyone will understand laughter. ... There’s a pattern generator in our brain that produces this sound.’’
    Each “ha’’ is about one-15th of a second, repeated every fifth of a second, he said. Laugh faster or slower than that and it sounds more like panting or something else. Deaf people laugh without hearing, and people on cell phones laugh without seeing, illustrating that laughter isn’t dependent on a single sense but on social interactions, said Provine, author of the book “Laughter: A Scientific Investigation.’’   
    “It’s joy, it’s positive engagement with life,’’ said Jaak Panksepp, a Bowling Green University psychology professor. “It’s deeply social.’’ And it’s not just a people thing either. Chimps tickle each other and even laugh when another chimp pretends to tickle them. By studying rats, Panksepp and other scientists can figure out what’s going on in the brain during laughter. And it holds promise for human ills.
    Northwestern biomedical engineering professor Jeffrey Burgdorf has found that laughter in rats produces an insulin-like growth factor chemical that acts as an antidepressant and anxietyreducer. He thinks the same thing probably happens in humans, too. This would give doctors a new chemical target in the brain in their effort to develop drugs that fight depression and anxiety in people. Even so, laughter itself hasn’t been proven to be the best medicine, experts said.

     So a scientist walks into a shopping mall to watch people laugh. There’s no punchline. Laughter is a serious scientific subject, one that researchers are still trying to figure out. Laughing is primal, our first way of communicating. Apes laugh. So do dogs and rats. Babies laugh long before they speak. No one teaches you how to laugh. You just do. And often you laugh involuntarily, in a specific rhythm and in certain spots in conversation.
    You may laugh at a prank on April Fools’ Day. But surprisingly,  only 10 to 15 percent of laughter is the result of someone making a joke, said Baltimore neuroscientist Robert Provine, who has studied laughter for decades. Laughter is mostly about social responses rather than reaction to a joke. “Laughter above all else is a social thing,’’ Provine said. “The requirement for laughter is another person.’’  
    Over the years, Provine, a professor with the University of Maryland Baltimore County, has boiled laughter down to its basics. “All language groups laugh ‘ha-ha-ha’ basically the same way,’’ he said. “Whether you speak Mandarin, French or English, everyone will understand laughter. ... There’s a pattern generator in our brain that produces this sound.’’
    Each “ha’’ is about one-15th of a second, repeated every fifth of a second, he said. Laugh faster or slower than that and it sounds more like panting or something else. Deaf people laugh without hearing, and people on cell phones laugh without seeing, illustrating that laughter isn’t dependent on a single sense but on social interactions, said Provine, author of the book “Laughter: A Scientific Investigation.’’   
    “It’s joy, it’s positive engagement with life,’’ said Jaak Panksepp, a Bowling Green University psychology professor. “It’s deeply social.’’ And it’s not just a people thing either. Chimps tickle each other and even laugh when another chimp pretends to tickle them. By studying rats, Panksepp and other scientists can figure out what’s going on in the brain during laughter. And it holds promise for human ills.
    Northwestern biomedical engineering professor Jeffrey Burgdorf has found that laughter in rats produces an insulin-like growth factor chemical that acts as an antidepressant and anxietyreducer. He thinks the same thing probably happens in humans, too. This would give doctors a new chemical target in the brain in their effort to develop drugs that fight depression and anxiety in people. Even so, laughter itself hasn’t been proven to be the best medicine, experts said.

     So a scientist walks into a shopping mall to watch people laugh. There’s no punchline. Laughter is a serious scientific subject, one that researchers are still trying to figure out. Laughing is primal, our first way of communicating. Apes laugh. So do dogs and rats. Babies laugh long before they speak. No one teaches you how to laugh. You just do. And often you laugh involuntarily, in a specific rhythm and in certain spots in conversation.
    You may laugh at a prank on April Fools’ Day. But surprisingly,  only 10 to 15 percent of laughter is the result of someone making a joke, said Baltimore neuroscientist Robert Provine, who has studied laughter for decades. Laughter is mostly about social responses rather than reaction to a joke. “Laughter above all else is a social thing,’’ Provine said. “The requirement for laughter is another person.’’  
    Over the years, Provine, a professor with the University of Maryland Baltimore County, has boiled laughter down to its basics. “All language groups laugh ‘ha-ha-ha’ basically the same way,’’ he said. “Whether you speak Mandarin, French or English, everyone will understand laughter. ... There’s a pattern generator in our brain that produces this sound.’’
    Each “ha’’ is about one-15th of a second, repeated every fifth of a second, he said. Laugh faster or slower than that and it sounds more like panting or something else. Deaf people laugh without hearing, and people on cell phones laugh without seeing, illustrating that laughter isn’t dependent on a single sense but on social interactions, said Provine, author of the book “Laughter: A Scientific Investigation.’’   
    “It’s joy, it’s positive engagement with life,’’ said Jaak Panksepp, a Bowling Green University psychology professor. “It’s deeply social.’’ And it’s not just a people thing either. Chimps tickle each other and even laugh when another chimp pretends to tickle them. By studying rats, Panksepp and other scientists can figure out what’s going on in the brain during laughter. And it holds promise for human ills.
    Northwestern biomedical engineering professor Jeffrey Burgdorf has found that laughter in rats produces an insulin-like growth factor chemical that acts as an antidepressant and anxietyreducer. He thinks the same thing probably happens in humans, too. This would give doctors a new chemical target in the brain in their effort to develop drugs that fight depression and anxiety in people. Even so, laughter itself hasn’t been proven to be the best medicine, experts said.

     So a scientist walks into a shopping mall to watch people laugh. There’s no punchline. Laughter is a serious scientific subject, one that researchers are still trying to figure out. Laughing is primal, our first way of communicating. Apes laugh. So do dogs and rats. Babies laugh long before they speak. No one teaches you how to laugh. You just do. And often you laugh involuntarily, in a specific rhythm and in certain spots in conversation.
    You may laugh at a prank on April Fools’ Day. But surprisingly,  only 10 to 15 percent of laughter is the result of someone making a joke, said Baltimore neuroscientist Robert Provine, who has studied laughter for decades. Laughter is mostly about social responses rather than reaction to a joke. “Laughter above all else is a social thing,’’ Provine said. “The requirement for laughter is another person.’’  
    Over the years, Provine, a professor with the University of Maryland Baltimore County, has boiled laughter down to its basics. “All language groups laugh ‘ha-ha-ha’ basically the same way,’’ he said. “Whether you speak Mandarin, French or English, everyone will understand laughter. ... There’s a pattern generator in our brain that produces this sound.’’
    Each “ha’’ is about one-15th of a second, repeated every fifth of a second, he said. Laugh faster or slower than that and it sounds more like panting or something else. Deaf people laugh without hearing, and people on cell phones laugh without seeing, illustrating that laughter isn’t dependent on a single sense but on social interactions, said Provine, author of the book “Laughter: A Scientific Investigation.’’   
    “It’s joy, it’s positive engagement with life,’’ said Jaak Panksepp, a Bowling Green University psychology professor. “It’s deeply social.’’ And it’s not just a people thing either. Chimps tickle each other and even laugh when another chimp pretends to tickle them. By studying rats, Panksepp and other scientists can figure out what’s going on in the brain during laughter. And it holds promise for human ills.
    Northwestern biomedical engineering professor Jeffrey Burgdorf has found that laughter in rats produces an insulin-like growth factor chemical that acts as an antidepressant and anxietyreducer. He thinks the same thing probably happens in humans, too. This would give doctors a new chemical target in the brain in their effort to develop drugs that fight depression and anxiety in people. Even so, laughter itself hasn’t been proven to be the best medicine, experts said.

     So a scientist walks into a shopping mall to watch people laugh. There’s no punchline. Laughter is a serious scientific subject, one that researchers are still trying to figure out. Laughing is primal, our first way of communicating. Apes laugh. So do dogs and rats. Babies laugh long before they speak. No one teaches you how to laugh. You just do. And often you laugh involuntarily, in a specific rhythm and in certain spots in conversation.
    You may laugh at a prank on April Fools’ Day. But surprisingly,  only 10 to 15 percent of laughter is the result of someone making a joke, said Baltimore neuroscientist Robert Provine, who has studied laughter for decades. Laughter is mostly about social responses rather than reaction to a joke. “Laughter above all else is a social thing,’’ Provine said. “The requirement for laughter is another person.’’  
    Over the years, Provine, a professor with the University of Maryland Baltimore County, has boiled laughter down to its basics. “All language groups laugh ‘ha-ha-ha’ basically the same way,’’ he said. “Whether you speak Mandarin, French or English, everyone will understand laughter. ... There’s a pattern generator in our brain that produces this sound.’’
    Each “ha’’ is about one-15th of a second, repeated every fifth of a second, he said. Laugh faster or slower than that and it sounds more like panting or something else. Deaf people laugh without hearing, and people on cell phones laugh without seeing, illustrating that laughter isn’t dependent on a single sense but on social interactions, said Provine, author of the book “Laughter: A Scientific Investigation.’’   
    “It’s joy, it’s positive engagement with life,’’ said Jaak Panksepp, a Bowling Green University psychology professor. “It’s deeply social.’’ And it’s not just a people thing either. Chimps tickle each other and even laugh when another chimp pretends to tickle them. By studying rats, Panksepp and other scientists can figure out what’s going on in the brain during laughter. And it holds promise for human ills.
    Northwestern biomedical engineering professor Jeffrey Burgdorf has found that laughter in rats produces an insulin-like growth factor chemical that acts as an antidepressant and anxietyreducer. He thinks the same thing probably happens in humans, too. This would give doctors a new chemical target in the brain in their effort to develop drugs that fight depression and anxiety in people. Even so, laughter itself hasn’t been proven to be the best medicine, experts said.