Questões de Inglês

Texto para a questão.

    During the nineteen-seventies and eighties, a researcher at the University of Washington started noticing something strange in the college’s experimental forest. For years, a blight of caterpillars had been munching the trees to death. Then, suddenly, the caterpillars themselves started dying off. The forest was able to recover. But what had happened to the caterpillars? The researcher, David Rhoades, who had a background in chemistry and zoology, found that the trees in the forest had changed the chemistry of their leaves, to the detriment of the caterpillars. Even more surprising, trees that had been nibbled by caterpillars weren’t the only ones that had changed their chemistry. Some were changing their leaves before caterpillars reached them, as if they’d received a warning. A shocking possibility presented itself: the trees were signalling to one another.

    Zoë Schlanger recounts Rhoades’s story in her new book, “The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth.”

    The contemporary world of botany that Schlanger explores in “The Light Eaters” is still divided over the matter of how plants sense the world and whether they can be said to communicate. But, in the past twenty years, the idea that plants communicate has gained broader acceptance. Research in recent decades has shown garden-variety lima beans protecting themselves by synthesizing and releasing chemicals to summon the predators of the insects that eat them; lab-grown pea shoots navigating mazes and responding to the sound of running water; and a chameleonic vine in the jungles of Chile mimicking the shape and color of nearby plants by a mechanism that’s not yet understood.

    Schlanger acknowledges that some of the research yields as many questions as answers. It’s not clear how the vine gathers information about surrounding plants to perform its mimicry.

New Yorker. 12 June 2024. Adaptado.

Texto para a questão.

    During the nineteen-seventies and eighties, a researcher at the University of Washington started noticing something strange in the college’s experimental forest. For years, a blight of caterpillars had been munching the trees to death. Then, suddenly, the caterpillars themselves started dying off. The forest was able to recover. But what had happened to the caterpillars? The researcher, David Rhoades, who had a background in chemistry and zoology, found that the trees in the forest had changed the chemistry of their leaves, to the detriment of the caterpillars. Even more surprising, trees that had been nibbled by caterpillars weren’t the only ones that had changed their chemistry. Some were changing their leaves before caterpillars reached them, as if they’d received a warning. A shocking possibility presented itself: the trees were signalling to one another.

    Zoë Schlanger recounts Rhoades’s story in her new book, “The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth.”

    The contemporary world of botany that Schlanger explores in “The Light Eaters” is still divided over the matter of how plants sense the world and whether they can be said to communicate. But, in the past twenty years, the idea that plants communicate has gained broader acceptance. Research in recent decades has shown garden-variety lima beans protecting themselves by synthesizing and releasing chemicals to summon the predators of the insects that eat them; lab-grown pea shoots navigating mazes and responding to the sound of running water; and a chameleonic vine in the jungles of Chile mimicking the shape and color of nearby plants by a mechanism that’s not yet understood.

    Schlanger acknowledges that some of the research yields as many questions as answers. It’s not clear how the vine gathers information about surrounding plants to perform its mimicry.

New Yorker. 12 June 2024. Adaptado.

Texto para a questão.

    Think for a minute about the little bumps on your tongue. You probably saw a diagram of those taste bud arrangements once in a biology textbook — sweet sensors at the tip, salty on either side, sour behind them, bitter in the back.

    But the idea that specific tastes are confined to certain areas of the tongue is a myth that “persists in the collective consciousness, despite decades of research debunking it”, according to a review published this month in The New England Journal of Medicine. Also wrong: the notion that taste is limited to the mouth.

    The old diagram, which has been used in many textbooks over the years, originated in a study published by David Hanig, a German scientist, in 1901. But the scientist was not suggesting that various tastes are segregated on the tongue. He was actually measuring the sensitivity of different areas, said Paul Breslin, a researcher at Monell Chemical Senses Center in Philadelphia. “What he found was that you could detect things at a lower concentration in one part relative to another,” Dr. Breslin said. The tip of the tongue, for example, is dense with sweet sensors but contains the others as well.

    The map’s mistakes are easy to confirm. If you place a lemon wedge at the tip of your tongue, it will taste sour, and if you put a bit of honey toward the side, it will be sweet.

    The perception of taste is a remarkably complex process, starting from that first encounter with the tongue. Taste cells have a variety of sensors that signal the brain when they encounter nutrients or toxins. For some tastes, tiny pores in cell membranes let taste chemicals in.

    Such taste receptors aren’t limited to the tongue; they are also found in the gastrointestinal tract, liver, pancreas, fat cells, brain, muscle cells, thyroid and lungs. We don’t generally think of these organs as tasting anything, but they use the receptors to pick up the presence of various molecules and metabolize them, said Diego Bohórquez, a self-described gut-brain neuroscientist at Duke University. For example, when the gut notices sugar in food, it tells the brain to alert other organs to get ready for digestion.

New York Times. May 29, 2024. Adaptado.

Texto para a questão.

    Think for a minute about the little bumps on your tongue. You probably saw a diagram of those taste bud arrangements once in a biology textbook — sweet sensors at the tip, salty on either side, sour behind them, bitter in the back.

    But the idea that specific tastes are confined to certain areas of the tongue is a myth that “persists in the collective consciousness, despite decades of research debunking it”, according to a review published this month in The New England Journal of Medicine. Also wrong: the notion that taste is limited to the mouth.

    The old diagram, which has been used in many textbooks over the years, originated in a study published by David Hanig, a German scientist, in 1901. But the scientist was not suggesting that various tastes are segregated on the tongue. He was actually measuring the sensitivity of different areas, said Paul Breslin, a researcher at Monell Chemical Senses Center in Philadelphia. “What he found was that you could detect things at a lower concentration in one part relative to another,” Dr. Breslin said. The tip of the tongue, for example, is dense with sweet sensors but contains the others as well.

    The map’s mistakes are easy to confirm. If you place a lemon wedge at the tip of your tongue, it will taste sour, and if you put a bit of honey toward the side, it will be sweet.

    The perception of taste is a remarkably complex process, starting from that first encounter with the tongue. Taste cells have a variety of sensors that signal the brain when they encounter nutrients or toxins. For some tastes, tiny pores in cell membranes let taste chemicals in.

    Such taste receptors aren’t limited to the tongue; they are also found in the gastrointestinal tract, liver, pancreas, fat cells, brain, muscle cells, thyroid and lungs. We don’t generally think of these organs as tasting anything, but they use the receptors to pick up the presence of various molecules and metabolize them, said Diego Bohórquez, a self-described gut-brain neuroscientist at Duke University. For example, when the gut notices sugar in food, it tells the brain to alert other organs to get ready for digestion.

New York Times. May 29, 2024. Adaptado.

Texto para a questão.

    Researchers investigated the quantities of thousands of muscle proteins and found a possible new explanation for muscle memory. A study showed for the first time that muscles "remember" training at the protein level. It is often thought that the effects of exercise are short-lived, and a break from the gym can cause stress over muscle loss. However, the research has shown that this stress is partly unnecessary, as the effects of resistance training persist in muscles for up to two months and the gains are fast when training is started again. But what mechanisms and changes at the cellular and molecular levels explain muscle memory? In the study, ten weeks of resistance training was followed by a break of the same length and then followed by another ten weeks of resistance training. Using the proteomics method, it was possible to study the quantities of over 3,000 muscle proteins using advanced mass spectrometry equipment. The study found two types of change profiles in muscle proteins. Some proteins changed as a result of training, returned to their pre-training state during the break, and changed again during the new training period similarly to the first training period. These included proteins related to aerobic metabolism. Another group of proteins changed as a result of training and remained changed during the break and after the new training period. Among these proteins were several calcium-binding proteins, such as calpain-2, whose gene has recently been identified to retain a memory trace even after a training break. "At the level of the number of muscle nuclei and the memory traces of genes, that is, epigenetics, long-term responses that persist even after a break and possibly explain 'muscle memory' have previously been observed," says a researcher. "Now, for the first time, we have shown that muscles 'remember' previous resistance training at the protein level for at least two and a half months."

Disponível em https://jyu.fi/en/news/. 14 April 2025. Adaptado.

Texto para a questão.

    Nearly a century ago, Edwin Hubble discovered that the universe is getting larger. Modern measurements of how fast it is expanding disagree, however, suggesting that our understanding of the laws of physics might be off. Everyone expected the sharp vision of the James Webb Space Telescope to bring the answer into focus. But a long-awaited analysis of the telescope’s observations released late Monday evening once again gleans conflicting expansion rates from different types of data, while homing in on possible sources of error at the heart of the conflict.

  Two rival teams have led the effort to measure the cosmic expansion rate, which is known as the Hubble constant, or H₀. One of these teams, led by Adam Riess of Johns Hopkins University, has consistently measured H0 to be about 8 percent higher than the theoretical prediction for how fast space should be expanding, based on the cosmos’s known ingredients and governing equations. This discrepancy, known as the Hubble tension, suggests that the theoretical model of the cosmos might be missing something—some extra ingredient or effect that speeds up cosmic expansion.

    Riess and his team released their latest measurement of H₀ based on Webb data this spring, getting a value that agrees with their earlier estimates.

    But for years a rival team led by Wendy Freedman of the University of Chicago has urged caution, arguing that cleaner measurements were needed. Her team’s own measurements of H0 have invariably landed closer than Riess’ to the theoretical prediction, implying that the Hubble tension may not be real.

    Since the Webb telescope started taking data in 2022, the astrophysics community has awaited Freedman’s multipronged analysis using the telescope’s observations of three types of stars. Now, the results are in: Two types of stars yield H0 estimates that align with the theoretical prediction, while the third—the same type of star Riess uses—matches his team’s higher H₀ value.

Disponível em https://wired.com/. 08 Sep 2024. Adaptado.