Tag Archives: solely

Small Discs Can Ascend to the Upper Atmosphere Solely Using Solar Energy

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Illustration of a solar-powered levitating disc

Schafer et al. Nature

A tiny disc, roughly the size of a nail, has the potential to ascend to high altitudes in sunlight while carrying sensors through some of the coldest and thinnest parts of the atmosphere. These swarms, flying higher than commercial aircraft and balloons, could reveal new insights regarding Earth’s evolving weather and climate.

These floating devices harness a phenomenon known as photophoresis. This was initially discovered over 150 years ago when chemist William Crookes invented a radiometer, a device with black and white feathers that spin when they are exposed to sunlight. The wings absorb light and release heat, increasing the momentum of nearby gas molecules. Due to the difference in temperature between the black and white sides of the wings, the black side emits more momentum, allowing the air to flow in one direction with sufficient force to turn the wings.

“We’ve embraced this lesser-known physics to develop applications that could benefit many people, enhancing our understanding of how weather and climate change unfolds over time.” Ben Schafer from Harvard University.

To create the levitating disc, Schafer and his team designed a device that spans 1 cm, composed of two sheets of aluminum oxide filled with microscale holes. When illuminated, the lower sheet, which contains alternating layers of chromium and aluminum oxide, heats up more than the top layer, similar to the black sides of the radiometer blades. This generates a directional airflow that moves upwards instead of sideways.

Under white LED and laser illumination — set to an intensity that mimics about 50% of natural sunlight — this upward force successfully lifted the device. This represents progress over previous solar-powered flyers, which required light intensity significantly brighter than sunlight. However, the tests were conducted under laboratory conditions with air pressure much lower than Earth’s surface pressure.

Fortunately, such low pressure conditions are common at higher altitudes, especially in the Mesosphere, which spans 50-85 km above the Earth. Researchers indicate that increasing the disc’s size to 3 centimeters could enable it to carry a 10-milligram payload to hard-to-reach research areas at altitudes of 75 km. Schafer has co-founded a startup, Rare Feed Technology, aiming to commercialize fleets of these high-flying devices for environmental monitoring and communications.

After sunset, computer modeling indicates that these discs could utilize the heat radiating from Earth’s surface to remain airborne. “If they can stay afloat during the night, that represents a significant advancement instead of simply descending and landing.” Igor Bargatin from the University of Pennsylvania, who is conducting similar research.

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Source: www.newscientist.com

AI chatbots are incapable of diagnosing patients solely through conversation

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Don’t call your favorite AI “Doctor” yet

Just_Super/Getty Images

Advanced artificial intelligence models have scored highly in professional medical examinations, but they are still challenging one of the most important doctor tasks: talking to patients, gathering relevant medical information, and providing accurate diagnoses. I am still neglecting one thing.

“Large-scale language models perform well on multiple-choice tests, but their accuracy drops significantly on dynamic conversations,” he says. Pranav Rajpurkar at Harvard University. “Models especially struggle with open-ended diagnostic inference.”

This became clear when researchers developed a method to assess the reasoning ability of clinical AI models based on simulated doctor-patient conversations. “Patients” is based on 2000 medical cases drawn primarily from the United States Medical Board Specialty Examinations.

“Simulating patient interactions allows assessment of history-taking skills, which is an important element of clinical practice that cannot be assessed through case descriptions,” he says. shreya jolialso at Harvard University. The new assessment benchmark, called CRAFT-MD, “reflects real-world scenarios where patients may not know what details are important to share and may only disclose important information if prompted by specific questions. “I do,” she says.

The CRAFT-MD benchmark itself relies on AI. OpenAI's GPT-4 model acted as a “patient AI” that conversed with the “clinical AI” being tested. GPT-4 also helped score the results by comparing the clinical AI's diagnosis with the correct answer for each case. Human medical experts reconfirmed these assessments. We also reviewed the conversations to confirm the accuracy of the patient AI and whether the clinical AI was able to gather relevant medical information.

Multiple experiments have shown that the performance of four major large-scale language models (OpenAI's GPT-3.5 and GPT-4 models, Meta's Llama-2-7b model, and Mistral AI's Mistral-v2-7b model) is performance on benchmarks was shown to be significantly lower than at the time. Makes a diagnosis based on a written summary of the case. OpenAI, Meta, and Mistral AI did not respond to requests for comment.

For example, GPT-4's diagnostic accuracy was an impressive 82 percent when a structured case summary was presented and the diagnosis could be selected from a list of multiple-choice answers, but not when a multiple-choice option was provided. However, when it had to make a diagnosis from a simulated patient conversation, its accuracy dropped to just 26%.

And GPT-4 performs best among the AI ​​models tested in this study, with GPT-3.5 often coming in second place, and Mistral AI models sometimes coming in second or third place. Meta's Llama models generally had the lowest scores.

AI models also failed to collect complete medical histories a significant proportion of the time, with the leading model, GPT-4, only able to do so in 71% of simulated patient conversations. Even if an AI model collects a patient's relevant medical history, it doesn't necessarily yield the correct diagnosis.

It says such simulated patient conversations are a “much more useful” way to assess an AI's clinical reasoning ability than medical tests. Eric Topol At the Scripps Research Institute Translational Institute in California.

Even if an AI model ultimately passes this benchmark and consistently makes accurate diagnoses based on conversations with simulated patients, it won't necessarily be better than a human doctor. says Rajpurkar. He points out that real-world medical procedures are “more troublesome” than simulations. That includes managing multiple patients, coordinating with medical teams, performing physical exams, and understanding the “complex social and systemic factors” in the local health care setting.

“While the strong performance in the benchmarks suggests that AI may be a powerful tool to support clinical practice, it does not necessarily replace the holistic judgment of experienced physicians.” says Rajpurkar.

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Source: www.newscientist.com

Scientists: Humans likely couldn’t survive solely on earthworms

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Earthworm meal?

The phrase “dining on earthworms” intrigues people in a variety of ways (whether or not they are intrigued in the first place). For historians, it can spark debates like this: Political rallies That happened in the German city of Worms in 1521. To nutritionists, the phrase can describe the work of scientists considering whether today's roughly 8 billion humans could all survive, if necessary, on a diet primarily of earthworms.

Henry Miller, James Mulhall, Lou Aino Pfau, Rachel Palm, and David Denkenberger, whom Feedback considers an all-star team in the earthworm nutrition community, recently devoured a mountain of data. After the meal, intellectually speaking, they said:Could harvesting earthworms significantly reduce global hunger in the event of a major disaster?” Published in the journal biomass.

The five researchers analyzed four techniques for efficiently capturing earthworms: digging and sorting, spraying with anthelmintics, making worm noises, and electric shocks.

They asked the “canned” (worm) question: Given the constraints of “scalability, climate-related collection barriers, and pre-consumption processing requirements,” could earthworms collected in these ways feed all of humanity? Their answer, in a word, is “no.”

Their 48-word response reads: “The authors are not aware of any studies on the human health effects of consuming diets high in harvested earthworms. However, in the authors' opinion, there is reasonable evidence that such diets may be harmful and therefore should not be recommended unless starvation is the alternative.”

Earthworm Meal

Miller, Mulhall, Pfau, Palm and Denkenberger are the latest pioneers in a long line of scientists who have come together to study earthworms' feeding habits.

Many others have focused on the feeding habits of the insects themselves.

Charles Darwin achieved some fame through his 1881 book, Formation of vegetable mold by the action of earthwormsNearly a century later, Christian Forchard and Peter Jummers wroteEarthworm diet: a study of the feeding guild of polychaetes” took up 92 pages. Annual Review of Oceanography and Marine Biology.

Forchard and Jumaz include a conversation-ending sentence that's worth memorizing and reciting if you want to impress at a party: “Alciopids are holoplanktonic animals with a muscular, eversable pharynx.”

Other scientists have studied what happens when insects are eaten, particularly by non-humans.

In 2002, Mary Silcox and Mark Teaford examined the teeth of several habitual earthworm eaters. They summarized their observations: Journal of Mammalogy,title”Insect diet: analysis of microwear on mole teeth” “.

“We measured microwear from the shear surfaces of mandibular molars. Parascallops Brewery (a hairy-tailed mole) Scapanus orarius “We compared the genes of (coast moles) with those of other small mammals, including tenrecs, hedgehogs, three species of primates and two species of bats.”

Some of the wear patterns on the mole's teeth “can plausibly be explained by interactions between the inner and outer teeth of the earthworm and the soil,” the researchers wrote.

Silcox and Teaford's mole teeth study may take on new importance if people on Earth choose to live a diet based primarily on earthworms, despite Miller and others' warnings.

Feedback has been received on the news regarding height requirements for certain courses at Vietnam National University’s School of Business Administration (HSB).

Deutsche Welle On July 2nd, the school announced that “this year's admission requirements are 1.58m or above for girls and 1.65m or above for boys,” because “the school aims to develop future leaders and excellent administrators” and “height is a determining factor, especially when it comes to leadership and self-confidence.”

The news report said that following public outcry, “HSB adjusted its admissions criteria” so that “the rule now applies to only one course – management and security.”

Are there schools or other institutions in the science, medical, or technology fields that have strict height requirements for students or employees? If so, please send us a document in Feedback with the subject line “Big/Small Careers.” Some job requirements reasonably specify that applicants must be physically able to use certain job-related equipment. Please do not send such requirements. We are seeking examples in Feedback where numbers, not needs, are prioritized.

Toilet Humor

Inspired by Feedback's collection of abandoned organisation slogans, Ken Taylor has been writing down slogans about abandoned things.

“I live in a very rural area. [the] UK – Cumbria. There are many isolated plots of land that are not connected to the sewer network and so rely on septic tanks, which need to be emptied regularly. I saw one such tanker truck carrying out its duties. The slogan on the side read “Move yesterday’s meal”. Nothing more to add…”

Marc Abrahams is the founder of the Ig Nobel Prize ceremony and co-founder of the journal Annals of Improbable Research. He previously worked on unusual uses of computers. His website is Impossible.

Do you have a story for feedback?

You can submit articles for Feedback by emailing feedback@newscientist.com. Please include your home address. This week's and past Feedback can be found on our website.


Source: www.newscientist.com

Instagram is experimenting with a dedicated feed focused solely on content from meta-verified users

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Instagram chief Adam Mosseri said the company is testing a feed that only shows posts from meta-verified users. The new toggle appears under the “Following” and “Favorites” options that appear when you click on his Instagram logo in the app.

“We’re testing a way for people to explore their Instagram feed and Reels by switching to only meta-verified accounts,” Mosseri said on Instagram’s broadcast channel. “We’re exploring this as a new control for people and a way for businesses and creators to be discovered.”

The official announcement comes two months after Instagram told TechCrunch that it had not tested such a feature after reverse engineering it. Alessandro Paluzzi We’ve noticed a new feed filter showing meta-authenticated subscribers in the code for both the iOS and Android Instagram apps.

Instagram seems to see the new feed as a way to drive meta-verified subscriptions and get people interested in subscribing. Because this new feed offers an opportunity to increase awareness. Meta Verified costs $11.99 per month on web and $14.99 per month on mobile, and gives users access to blue checkmarks, enhanced customer support, increased visibility and reach in searches and comments, exclusive stickers, and more.

Meta is clearly borrowing from Elon Musk’s playbook with the new Verified-only feed and Meta Verified in general. After Tesla’s CEO acquired Twitter (now X) last fall, the social network launched paid authentication through its revamped X Premium subscription service at $8 per month.With a subscription, users can various functions, the user’s notifications will include a “Verified” tab. The service also includes other features such as an edit button and support for long posts.

Source: techcrunch.com