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384.Spring-fed - подпитываемый, наполняемый родниками, подземными источниками

385.To dwell - обитать

386.Aspen - осина

387.Woodland - лесной массив; лесистая местность

388.To flutter - дрожать, колыхаться, развеваться

389.Longevity - долголетие, долговечность

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Deer are eating the youngest 'trees'

Overgrazing by deer and elk is one of the biggest worries. Wolves and cougars once kept their numbers in check, but herds are now much larger because of the loss of these predators.

Deer and elk also tend to собираться in Pando as the protection the woodland receives means they are not in danger of being hunted there.

As older trees die or fall down, light reaches the woodland floor which stimulates new clonal stems to start growing, but when these animals eat the tops off newly forming stems, they die. This means in large portions of Pando there is little new growth.

The exception is one area that was отгорожена a few decades ago to remove dying trees. This fenced-off area has не допускала elk and deer and has seen successful regeneration of new clonal stems, with dense growth referred to as the "bamboo garden".

Diseases and climate change

Older stems in Pando are also being affected by at least three diseases: тёмно-коричневый bark рак растений, leaf spot and conk fungal disease.

While plant diseases have developed and thrived in aspen stands for millennia, it is unknown what the long-term effect on the ecosystem may be, given that there is a lack of new growth and an ever-growing list of other pressures on the clonal giant.

The fastest-growing threat is that of climate change. Pando arose after the last ice age had passed and has dealt with a largely stable climate ever since.

To be sure, it inhabits an alpine region surrounded by desert, meaning it is no stranger to warm temperatures or drought. But climate change threatens the size and продолжительность жизни of the tree, as well as the whole ecosystem it hosts.

Although no scientific studies have focused specifically on Pando, aspen stands have been struggling with climate change-related pressures, such as reduced water supply and warmer weather earlier in the year, making it harder for trees to form new leaves, which have led to declines in coverage.

With more competition for ever-dwindling water resources (the nearby Fish Lake is just out of reach of the tree's root system), temperatures expected to continue soaring to record highs in summer, and the threat of more intense wildfires, Pando will certainly struggle to adjust to these fast-changing conditions while maintaining its size.

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390.To congregate - собираться, сходиться

391.To fence-off - отгораживать

392.To exclude - не допускать, не впускать, исключать

393.Sooty - тёмно-коричневый, покрытый сажей

394.Canker - рак растений, некроз плодовых деревьев

395.Lifespan - продолжительность жизни

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The next 14,000 years

Yet Pando is быстро отправляющийся and has already survived rapid environmental changes, especially when European settlers began inhabiting the area in the 19th century or after the rise of 20th-century recreational activities.

It has dealt with disease, wildfire, and grazing before and remains the world's largest scientifically documented organism.

Despite every cause for concern, there is hope as scientists are helping us unlock the secrets to Pando's resilience, while conservation groups and the US forest service are working to protect this tree and its associated ecosystem. And a new group called the Friends of Pando aims to make the tree accessible to virtually everyone through 360 video recordings.

Last summer, when I was visiting my family in Utah, I took the chance to visit Pando. I spent two amazing days walking under возвышающимися mature stems swaying and "quaking" in the gentle breeze, between the thick new growth in the "bamboo garden", and even into charming meadows that puncture portions of the otherwise-enclosed center.

I восхищался at the wildflowers and other plants thriving under the рассеяной тенью крон деревьев, and I was able to take delight in spotting опыляющих insects, birds, fox, beaver, and deer, all using some part of the ecosystem created by Pando.

It's these moments that remind us that we have plants, animals, and ecosystems worth protecting. In Pando, we get the rare chance to protect all three.

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396.Resilient - быстро оправляющийся (от невзгод, горя и т. д.), имеющий запас жизненных сил

397.To tower - выситься, возвышаться

398.To marvel - дивиться, изумляться, восхищаться

399.Dappled shade - рассеянная тень (не сплошная)

400.Canopy - шатёр из листьев, крон деревьев

401.To pollinate - опылять

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🕯 Article 21

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The superfoods that fueled ancient Andeans through 2,500 years of беспорядка

What if Indigenous diets could save, our politically and ecologically strained planet? The answer may lie in the success of an ancient civilization high in the Andes Mountains, where not much grows.

UC Berkeley archaeologists reconstructed the diets of ancient Andeans living around Lake Titicaca, which straddles Bolivia and Peru 12,500 feet above sea level. They found that quinoa, potatoes and лама meat helped питать, подпитывать the Tiwanaku civilization through 2,500 years of political and climate сдвига.

The findings, appearing this week in the Proceedings of the National Academy of Sciences journal, help explain the endurance of Andean cultural practices in the millennia preceding the Inca Empire. Moreover, they подчёркивают the contribution of traditional Indigenous foods to human resilience.

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401.Turmoil - суматоха, беспорядок, смятение

402.Llama - лама

403.To fuel - питать, поддерживать

404.Upheaval - сдвиг

405.To underscore - подчёркивать

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"Thousands of years ago, these people already knew that quinoa was a superfood. They came up with this lucky triangle to meet their dietary needs in a pretty бесплодном environment, and we can learn something from them," said study senior author Christine Hastorf, a UC Berkeley professor of anthropology.

"Today, we're living under the cloud of climate change. Rising sea levels are drowning tiny Pacific islands, and droughts and wildfires are destroying California's crops," she added. "Our findings point to how ancient people successfully adjusted to environmental and political changes, поддерживаемые by a healthy Indigenous diet."

Through a передовые scientific process known as compound-specific stable isotope analysis of amino acids, study lead author Melanie Miller analyzed human teeth from excavated burials on the southern shores of Lake Titicaca to reconstruct the ancient Andeans' diet. The remains date between 1400 B.C. and A.D. 1100.

"Our study documents dietary resilience across millennia in the face of long-term climate and political changes, and shows how studying past societies under these kinds of stressors can potentially help us in the future," said Miller, a research associate with UC Berkeley's Archaeological Research Facility and a postdoctoral учёный, занимающийся исследованиями at New Zealand's University of Otago.

The results challenge the assumption that fish from Lake Titicaca and corn, also known as maize, were major sources of dietary protein and fiber on the Taraco Peninsula, which выступает, выдаётся from the lake

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406.Stark - пустынный, бесплодный

407.To bolster - поддерживать, укреплять

408.Cutting-edge - передовой, современный

409.Fellow - учёный, научный сотрудник, занимающийся исследовательской работой

410.To jut out - выступать, выдаваться

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Corn was most likely consumed as an alcoholic beverage known as chicha and reserved for special occasions, while съедобные клубни, meat from верблюдовых like llama and alpaca, and the nutrient-rich seeds of the flowering Chenopodium quinoa plant were the predominant staples, the study found.

"These people are living right on the shores of Lake Titicaca, and there's a lot of references to fish in the archeological record. So, we had always assumed that the people there had been using the lake as a resource," Miller said.

"But through isotopic testing, we actually found they were not relying on the lake for their primary source of protein," she added. "Instead, they were investing in quinoa, potatoes and llamas, which have a long history of domestication in the area."

For their experiment, the researchers took очень маленькие samples of dental tissue from the human remains and tested the collagen in the tissue to identify chemical components that could tell them more about the specific kinds of food being consistently consumed over long time periods.

Hastorf has studied the history and culture of the Taraco Peninsula from 1500 B.C. to A.D. 1100, during which time the region evolved from a predominantly agrarian society to a sophisticated Andean civilization whose urban center was Tiwanaku.
Lake Titicaca is sacred to both the Tiwanaku and the Inca people. Also sacred to these Andean civilizations was quinoa, which can grow at high высотах in arid, salty soil. It contains essential amino acids and is a source of vitamin E, B2, calcium, калий and phosphorus and other nutrients, hence its classification as a superfood.

"Before, we had an idea of what these people were eating, but we had numerous questions about which foods were important over time and who was eating them," Hastorf said. "Now we know the foods that helped them thrive in this extreme environment and through multiple climatic changes. They were the original superfood eaters, and they prospered."

"In the face of long-term catastrophic conditions," she added, "we, too, may need to return to traditional crops and food groups that grow best where we live."

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411.Tuber - клубень, съедобный корень

412.Camelids - верблюдовые

413.Miniscule - ['mɪnəskjuːl] - очень маленький

414. Elevation - высота (над уровнем море)

415.Potassium - [pəʹtæsıəm] - калий (химический элемент)

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🕯 Article 22

#article

How C. elegans worms avoid getting poisoned

Javier Apfeld approached the question like a worm detective. Except, instead of solving a волнистые, с завитушками creature's murder, the biologist was trying to understand why worms didn't die, despite a deadly toxin's common presence in the environments in which they live.

The verdict: The worms know how to detect and увернуться the chemical threat. A trick they use, as Apfeld and colleagues describe in a new paper published in PLOS Pathogens, is that they know how to get by with a little help from their food.

And, says Apfeld, an assistant professor of biology at Northeastern, understanding the worms' methods could help us understand how other creatures—including humans—that face that same toxic threat may поставить безвыходное положение that chemical врага.

The worm in question is called Caenorhabditis elegans, and it's a type of microscopic roundworm often used as a model organism to study human diseases. One of the biggest threats to its existence is a common substance: hydrogen peroxide.

Hydrogen peroxide can be fatal for all kinds of organisms to encounter. The chemical compound reacts easily with other molecules, and can break down cell walls. It's found all over the natural world, particularly in the microscopic spheres as it is produced by a wide множество of microorganisms

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416.Wiggly - волнистый, с завитушками

417.To dodge - уклоняться, увёртываться

418.To stymie - поставить в безвыходное положение, загнать в угол

419.Foe - враг

420.Array - множество, масса

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Hydrogen peroxide is so common that many organisms have evolved defense mechanisms against its toxicity. One method is to produce enzymes that разлагают the chemical toxin and prevent it from doing damage. Worms are no different.

But in a previous study, Apfeld and his team noticed a peculiar thing: C. elegans turn off their hydrogen-peroxide defenses when they eat.

"It seemed kind of weird at first," he says. "But it turns out that the bacteria the worms eat have similar defenses, these enzymes that degrade peroxide."

Apfeld предположил, высказал догадку that perhaps when worms smell food, they figure that they'll be able to co-opt that bacteria's protection for themselves. From the worms' perspective, it makes sense, he says: "Why вызывать, стимулировать a protection when you can freeload off the protection from the bacteria?"

But not all bacteria offer the worms the same protection. So could worms actually tell the difference between which snack would protect them and which wouldn't?

Apfeld put the question to students in his laboratory. They set up several experiments that forced the worms to choose between different foods in a petri dish—sometimes in the presence of hydrogen peroxide.

In one experiment, the researchers gave the worms the choice between bacteria that degrades hydrogen peroxide and bacteria that doesn't. They'd place a worm in between the two choices in the petri dish and watch where it went.

Not surprisingly, "when there was peroxide around, the worms really had a strong preference for the bacteria that protected them," Apfeld says. Sometimes the worms would go both places, but once they sensed that the bacteria wasn't going to protect them, they'd usually leave that food.

But not always, Apfeld says. "It's a difficult decision" for the worms, he says. "Do you leave the food? Because if you leave the food, you may not encounter food again and die. And if you stay, you may die, too," if there is hydrogen peroxide around.

To dig deeper into C. elegans' decision-making, Apfeld collaborated with Vivek Venkatachalam, assistant professor of physics at Northeastern, and his laboratory to image the brain activity associated with these choices. The team identified which neurons responded to the presence of hydrogen peroxide in the environment, and which would respond to food.

The researchers found that given an environment with both food and hydrogen peroxide, only one of the neurological responses would win. If the bacteria offered less protection, the food-seeking neurological mechanism was less likely to win, and the worm would put its energy into escaping the threat of hydrogen peroxide rather than питаться on the bacteria.

"They are responding to the concentration of food, the concentration of peroxide," Apfeld says. "But we are only beginning to understand how the worms make decisions and how they respond to conflicting cues."

Further investigation, he says, is warranted to better understand how the brain coordinates the мешанину of sensory inputs that signal danger, food, and other important indicators for survival. And understanding them in worms might yield clues about how creatures with more complex neurological systems (like humans) know how to react in ways to keep themselves safe.

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421.To degrade - разлагать

422.To surmise - предполагать, высказывать догадку

423.To induce - вызывать, стимулировать

424.To chow down - есть, питаться

425.Patchwork - путаница, ералаш, мешанина

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🕯Article 23

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