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🔗 Medicine 🔗 Medicine/Neurology 🔗 Medicine/Medical genetics

Williams syndrome (WS) is a genetic disorder that affects many parts of the body. Facial features frequently include a broad forehead, short nose and full cheeks, an appearance that has been described as "elfin". While mild to moderate intellectual disability with particular problems with visual spatial tasks such as drawing is typical, verbal skills are generally relatively unaffected. Those affected often have an outgoing personality, interact readily with strangers, and appear happy. Problems with teeth, heart problems, especially supravalvular aortic stenosis, and periods of high blood calcium are common.

Williams syndrome is caused by a genetic abnormality, specifically a deletion of about 27 genes from the long arm of one of the two chromosome 7s. Typically this occurs as a random event during the formation of the egg or sperm from which a person develops. In a small number of cases, it is inherited from an affected parent in an autosomal dominant manner. The different characteristic features have been linked to the loss of specific genes. The diagnosis is typically suspected based on symptoms and confirmed by genetic testing.

Treatment includes special education programs and various types of therapy. Surgery may be done to correct heart problems. Dietary changes or medications may be required for high blood calcium. The syndrome was first described in 1961 by New Zealander John C. P. Williams. Williams syndrome affects between 1 in 7,500 to 1 in 20,000 people at birth. Life expectancy is less than that of the general population, mostly due to the increased rates of heart disease.

🔗 Physics 🔗 Philosophy 🔗 Philosophy/Metaphysics

The Boltzmann brain argument suggests that it is more likely for a single brain to spontaneously and briefly form in a void (complete with a false memory of having existed in our universe) than it is for our universe to have come about in the way modern science thinks it actually did. It was first proposed as a reductio ad absurdum response to Ludwig Boltzmann's early explanation for the low-entropy state of our universe.

In this physics thought experiment, a Boltzmann brain is a fully formed brain, complete with memories of a full human life in our universe, that arises due to extremely rare random fluctuations out of a state of thermodynamic equilibrium. Theoretically over a period of time on the order of hundreds of billions of years, by sheer chance atoms in a void could spontaneously come together in such a way as to assemble a functioning human brain. Like any brain in such circumstances, it would almost immediately stop functioning and begin to deteriorate.

The idea is ironically named after the Austrian physicist Ludwig Boltzmann (1844–1906), who in 1896 published a theory that tried to account for the fact that we find ourselves in a universe that is not as chaotic as the budding field of thermodynamics seemed to predict. He offered several explanations, one of them being that the universe, even one that is fully random (or at thermal equilibrium), would spontaneously fluctuate to a more ordered (or low-entropy) state. One criticism of this "Boltzmann universe" hypothesis is that the most common thermal fluctuations are as close to equilibrium overall as possible; thus, by any reasonable criterion, actual humans in the actual universe would be vastly less likely than "Boltzmann brains" existing alone in an empty universe.

Boltzmann brains gained new relevance around 2002, when some cosmologists started to become concerned that, in many existing theories about the Universe, human brains in the current Universe appear to be vastly outnumbered by Boltzmann brains in the future Universe who, by chance, have exactly the same perceptions that we do; this leads to the conclusion that statistically we ourselves are likely to be Boltzmann brains. Such a reductio ad absurdum argument is sometimes used to argue against certain theories of the Universe. When applied to more recent theories about the multiverse, Boltzmann brain arguments are part of the unsolved measure problem of cosmology. Boltzmann brains remain a thought experiment; physicists do not believe that we are actually Boltzmann brains, but rather use the thought experiment as a tool for evaluating competing scientific theories.

🔗 Literature

Some writers have had prolific careers with hundreds of their works being published. While some best-selling authors have written a small number of books that have sold millions of copies, others have had lengthy careers and maintained a high level of output year after year. Dame Agatha Christie, the most-published novelist in history, is estimated to have sold 4 billion books, having written 69 novels and 19 plays. Her works were published between 1920 and 1976, equating to around three publications every two years. Dame Barbara Cartland has also sold millions of copies of her books but wrote many more than Christie. She spent 80 years as a novelist with 722 books published, averaging one book released every 40 days of her career. While Cartland wrote a significant number of full-length novels, other authors have been published many more times but have specialised in short stories. Spanish author Corín Tellado wrote over 4,000 novellas, selling 400 million copies of her books.

Not all authors work alone. Groups of writers, sometimes led by one central figure, have published under shared pseudonyms. The Stratemeyer Syndicate, started by Edward Stratemeyer in 1905, created numerous book series including 190 volumes of The Hardy Boys and 175 volumes of Nancy Drew. More than 1,300 books were published by the group, and although Edward L. Stratemeyer wrote several hundred, he also employed ghostwriters to keep up with the demand. These writers were given storylines and strict guidelines to follow to ensure a level of consistency within each series. Amongst the writing team was Howard R. Garis, who contributed several hundred books to the collection, one of the most active authors. Sales were estimated at over two hundred million copies before the syndicate was sold to Simon & Schuster in 1984.

Most authors carefully craft their work, writing and rewriting several times before publication. Some authors simply use pen and paper, while others such as Isaac Asimov spent hours at a stretch working at a typewriter. Philip M. Parker, by one measure the world's most prolific author, has an entirely different approach. Parker has over 200,000 titles listed on Amazon.com, having developed an algorithm to gather publicly available data and compile it into book form. The computer-generated nature of the books is not detailed on the sales page and the books are printed only when ordered.

🔗 Biography 🔗 Biography/sports and games 🔗 Gambling/Poker 🔗 Gambling

Stuart Errol Ungar (September 8, 1953 – November 22, 1998) was an American professional poker, blackjack, and gin rummy player, widely regarded to have been the greatest Texas hold 'em and gin player of all time.

He is one of two people in poker history to have won the World Series of Poker Main Event three times. He is the only person to win Amarillo Slim's Super Bowl of Poker three times, the world's second most prestigious poker title during its time. He is one of four players in poker history to win consecutive titles in the WSOP Main Event, along with Johnny Moss, Doyle Brunson and Johnny Chan.

🔗 Mathematics

In geometric topology, the Clifford torus is the simplest and most symmetric flat embedding of the cartesian product of two circles S¹_a and S¹_b (in the same sense that the surface of a cylinder is "flat"). It is named after William Kingdon Clifford. It resides in R⁴, as opposed to in R³. To see why R⁴ is necessary, note that if S¹_a and S¹_b each exist in their own independent embedding spaces R²_a and R²_b, the resulting product space will be R⁴ rather than R³. The historically popular view that the cartesian product of two circles is an R³ torus in contrast requires the highly asymmetric application of a rotation operator to the second circle, since that circle will only have one independent axis z available to it after the first circle consumes x and y.

Stated another way, a torus embedded in R³ is an asymmetric reduced-dimension projection of the maximally symmetric Clifford torus embedded in R⁴. The relationship is similar to that of projecting the edges of a cube onto a sheet of paper. Such a projection creates a lower-dimensional image that accurately captures the connectivity of the cube edges, but also requires the arbitrary selection and removal of one of the three fully symmetric and interchangeable axes of the cube.

If S¹_a and S¹_b each has a radius of ${\displaystyle \textstyle {\sqrt {1/2}}}$, their Clifford torus product will fit perfectly within the unit 3-sphere S³, which is a 3-dimensional submanifold of R⁴. When mathematically convenient, the Clifford torus can be viewed as residing inside the complex coordinate space C², since C² is topologically equivalent to R⁴.

The Clifford torus is an example of a square torus, because it is isometric to a square with opposite sides identified. It is further known as a Euclidean 2-torus (the "2" is its topological dimension); figures drawn on it obey Euclidean geometry as if it were flat, whereas the surface of a common "doughnut"-shaped torus is positively curved on the outer rim and negatively curved on the inner. Although having a different geometry than the standard embedding of a torus in three-dimensional Euclidean space, the square torus can also be embedded into three-dimensional space, by the Nash embedding theorem; one possible embedding modifies the standard torus by a fractal set of ripples running in two perpendicular directions along the surface.

🔗 Computing

A stack-oriented programming language is one that relies on a stack machine model for passing parameters. Several programming languages fit this description, notably Forth, RPL, PostScript, BibTeX style design language and many assembly languages (on a much lower level).

Stack-oriented languages operate on one or more stacks, each of which may serve a different purpose. Thus, programming constructs in other programming languages may need to be modified for use in a stack-oriented system. Further, some stack-oriented languages operate in postfix or Reverse Polish notation, that is, any arguments or parameters for a command are stated before that command. For example, postfix notation would be written 2, 3, multiply instead of multiply, 2, 3 (prefix or Polish notation), or 2 multiply 3 (infix notation).

🔗 Computer Security 🔗 Computer Security/Computing 🔗 Microsoft Windows 🔗 Microsoft Windows/Computing 🔗 Cryptography 🔗 Cryptography/Computer science

_NSAKEY was a variable name discovered in an operating system from Microsoft in 1999. The variable contained a 1024-bit public key; such keys are used in cryptography for encryption and authentication. Due to the name it was speculated that the key was owned by the United States National Security Agency (the NSA) which would allow the intelligence agency to subvert any Windows user's security. Microsoft denied the speculation and said that the key's name came from the NSA being the technical review authority for U.S. cryptography export controls.

The key was discovered in a Windows NT 4 Service Pack 5 (which had been released unstripped of its symbolic debugging data) in August 1999 by Andrew D. Fernandes of Cryptonym Corporation.

🔗 Soviet Union 🔗 Russia 🔗 Russia/language and literature of Russia 🔗 Russia/history of Russia 🔗 Georgia (country)

Before he became a Bolshevik revolutionary and the leader of the Soviet Union, Joseph Stalin was a promising poet.

The Berlin key (also known as, German, Schließzwangschlüssel, or, in English, forced-locking key) is a key for a type of door lock. It was designed to force people to close and lock their doors, usually a main entrance door or gate leading into a common yard or tenement block. The key was a solution to the problem of access via communal doors of such blocks (Mietskaserne) as early as the 19th century.

🔗 Physics 🔗 Electronics 🔗 Professional sound production

Pink noise or ​¹⁄_f noise is a signal or process with a frequency spectrum such that the power spectral density (energy or power per frequency interval) is inversely proportional to the frequency of the signal. In pink noise, each octave (halving or doubling in frequency) carries an equal amount of noise energy.

Pink noise is one of the most common signals in biological systems.

The name arises from the pink appearance of visible light with this power spectrum. This is in contrast with white noise which has equal intensity per frequency interval.