Random Articles (Page 278)
Have a deep view into what people are curious about.
๐ Protein Leverage Hypothesis
The protein leverage hypothesis states that human beings will prioritize the consumption of protein in food over other dietary components, and will eat until protein needs have been met, regardless of energy content, thus leading to over-consumption of foodstuffs when their protein content is low.
This hypothesis has been put forward as a potential explanation of the obesity epidemic. Empirical tests have provided some evidence to confirm the hypothesis with one study suggesting that this could be a link between ultra-processed foods and the prevalence of obesity in the developed world.
In the 1980s, David Raubenheimer and Stephen Simpson, researchers now at the University of Sydney, began to study appetite and food intake in locusts. By studying responses to artificial diets with differing compositions of protein and carbohydrate, they developed the protein leverage hypothesis. Their experiments showed that those who aren't getting enough protein in their diet will continue to be hungry, even when their overall caloric intake is high. "Protein decoys", such as ultraprocessed savory foods that contain little protein (e.g., barbecue chips), are likely to be attractive and to result in overeating. The hormone FGF21, which is released from the liver, can drive savory-seeking behavior under conditions of low protein intake. However, extremely high protein diets can also have drawbacks. In 2020 Simpson and Raubenheimer published the popular science book Eat Like the Animals: What Nature Teaches Us about the Science of Healthy Eating, which details their experiments. For lifelong health they recommend eating a balanced diet with more fiber and fewer fats and carbohydrates rather than an extremely high protein diet.
In 1995, Australian researcher Susanna Holt developed the concept of satiety value, a measure of how much a given food is likely to satisfy the hunger of someone. High protein foods have been found to have high satiety values, though these are outmatched by potatoes and oats (which have a low glycemic index). Fruits rank similarly to high protein foods (likely due to their high level of dietary fibre).
๐ Thomas Stevens (Cyclist)
Thomas Stevens (24 December 1854 โ 24 January 1935) was the first person to circle the globe by bicycle. He rode a large-wheeled Ordinary, also known as a penny-farthing, from April 1884 to December 1886. He later searched for Henry Morton Stanley in Africa, investigated the claims of Indian ascetics and became manager of the Garrick Theatre in London.
Discussed on
- "Thomas Stevens (Cyclist)" | 2024-02-03 | 42 Upvotes 9 Comments
๐ Stationary Bandit Theory
Theory of the Stationary Bandit โ theory of the origin of the state, developed by American scholars Martin C. McGuire and Mansur Olson.
๐ Pemmican
Pemmican (also pemican in older sources) is a mixture of tallow, dried meat, and sometimes dried berries. A calorie-rich food, it can be used as a key component in prepared meals or eaten raw. Historically, it was an important part of indigenous cuisine in certain parts of North America and it is still prepared today. The word comes from the Cree word แฑแฆแฆแณแ (pimรฎhkรขn), which is derived from the word แฑแฅแ (pimรฎ), "fat, grease". The Lakota (or Sioux) word is wasnรก, originally meaning "grease derived from marrow bones", with the wa- creating a noun, and snรก referring to small pieces that adhere to something. It was invented by the Indigenous peoples of North America.
Pemmican was widely adopted as a high-energy food by Europeans involved in the fur trade and later by Arctic and Antarctic explorers, such as Captain Robert Bartlett, Ernest Shackleton, Richard E. Byrd, Fridtjof Nansen, Robert Falcon Scott, George W. DeLong, and Roald Amundsen.
Discussed on
- "Pemmican" | 2023-10-29 | 33 Upvotes 12 Comments
๐ The Beale ciphers
The Beale ciphers (or Beale Papers) are a set of three ciphertexts, one of which allegedly states the location of a buried treasure of gold, silver and jewels estimated to be worth over US$43ย million as of Januaryย 2018. Comprising three ciphertexts, the first (unsolved) text describes the location, the second (solved) ciphertext the content of the treasure, and the third (unsolved) lists the names of the treasure's owners and their next of kin.
The story of the three ciphertexts originates from an 1885 pamphlet detailing treasure being buried by a man named Thomas J. Beale in a secret location in Bedford County, Virginia, in the 1820s. Beale entrusted a box containing the encrypted messages to a local innkeeper named Robert Morriss and then disappeared, never to be seen again. According to the story, the innkeeper opened the box 23ย years later, and then decades after that gave the three encrypted ciphertexts to a friend before he died. The friend then spent the next twenty years of his life trying to decode the messages, and was able to solve only one of them which gave details of the treasure buried and the general location of the treasure. The unnamed friend then published all three ciphertexts in a pamphlet which was advertised for sale in the 1880s.
Since the publication of the pamphlet, a number of attempts have been made to decode the two remaining ciphertexts and to locate the treasure, but all efforts have resulted in failure.
There are many arguments that the entire story is a hoax, including the 1980 article "A Dissenting Opinion" by cryptographer Jim Gillogly, and a 1982 scholarly analysis of the Beale Papers and their related story by Joe Nickell, using historical records that cast doubt on the existence of Thomas J. Beale. Nickell also presents linguistic evidence demonstrating that the documents could not have been written at the time alleged (words such as "stampeding", for instance, are of later vintage). His analysis of the writing style showed that Beale was almost certainly James B. Ward, whose 1885 pamphlet brought the Beale Papers to light. Nickell argues that the tale is thus a work of fiction; specifically, a "secret vault" allegory of the Freemasons; James B. Ward was a Mason himself.
Discussed on
- "The Beale ciphers" | 2014-09-28 | 33 Upvotes 9 Comments
๐ Q-Learning
Q-learning is a model-free reinforcement learning algorithm to learn a policy telling an agent what action to take under what circumstances. It does not require a model (hence the connotation "model-free") of the environment, and it can handle problems with stochastic transitions and rewards, without requiring adaptations.
For any finite Markov decision process (FMDP), Q-learning finds an optimal policy in the sense maximizing the expected value of the total reward over any and all successive steps, starting from the current state. Q-learning can identify an optimal action-selection policy for any given FMDP, given infinite exploration time and a partly-random policy. "Q" names the function that returns the reward used to provide the reinforcement and can be said to stand for the "quality" of an action taken in a given state.
Discussed on
- "Q-Learning" | 2019-08-13 | 88 Upvotes 33 Comments
๐ Sraffa asks Wittgenstein: โWhat is the logical form of that?โ
Piero Sraffa (5 August 1898 โ 3 September 1983) was an influential Italian economist who served as lecturer of economics at the University of Cambridge. His book Production of Commodities by Means of Commodities is taken as founding the neo-Ricardian school of economics.
Discussed on
- "Sraffa asks Wittgenstein: โWhat is the logical form of that?โ" | 2023-02-03 | 13 Upvotes 1 Comments
๐ List of company name etymologies
This is a list of company names with their name origins explained. Some of the origins are disputed.
Discussed on
- "List of company name etymologies" | 2011-09-27 | 66 Upvotes 12 Comments
๐ Problem of Time
In theoretical physics, the problem of time is a conceptual conflict between general relativity and quantum mechanics in that quantum mechanics regards the flow of time as universal and absolute, whereas general relativity regards the flow of time as malleable and relative. This problem raises the question of what time really is in a physical sense and whether it is truly a real, distinct phenomenon. It also involves the related question of why time seems to flow in a single direction, despite the fact that no known physical laws seem to require a single direction.
Discussed on
- "Problem of Time" | 2020-04-05 | 63 Upvotes 49 Comments
๐ Diffractive Solar Sail
A diffractive solar sail, or diffractive lightsail, is a type of solar sail which relies on diffraction instead of reflection for its propulsion. Current diffractive sail designs use thin metamaterial films, containing micrometer-size gratings based on polarization or subwavelength refractive structures, causing light to spread out (i.e. diffract) and thereby exert radiation pressure when it passes through them.
Discussed on
- "Diffractive Solar Sail" | 2023-11-03 | 45 Upvotes 16 Comments