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🔗 Computing

ECMAScript for XML (E4X) is the standard ISO/IEC 22537:2006 [1] programming language extension that adds native XML support to ECMAScript (which includes ActionScript, JavaScript, and JScript). The goal is to provide an alternative to DOM interfaces that uses a simpler syntax for accessing XML documents. It also offers a new way of making XML visible. Before the release of E4X, XML was always accessed at an object level. E4X instead treats XML as a primitive (like characters, integers, and booleans). This implies faster access, better support, and acceptance as a building block (data structure) of a program.

E4X is standardized by Ecma International in the ECMA-357 standard. The first edition was published in June 2004, the second edition in December 2005.

The E4X standard was deprecated by the Mozilla Foundation in 2014.

Mithridatism is the practice of protecting oneself against a poison by gradually self-administering non-lethal amounts. The word is derived from Mithridates VI, the King of Pontus, who so feared being poisoned that he regularly ingested small doses, aiming to develop immunity.

🔗 Systems 🔗 Systems/Chaos theory

In mathematics, the Menger sponge (also known as the Menger cube, Menger universal curve, Sierpinski cube, or Sierpinski sponge) is a fractal curve. It is a three-dimensional generalization of the one-dimensional Cantor set and two-dimensional Sierpinski carpet. It was first described by Karl Menger in 1926, in his studies of the concept of topological dimension.

🔗 Mathematics 🔗 Etymology

Zenzizenzizenzic is an obsolete form of mathematical notation representing the eighth power of a number (that is, the zenzizenzizenzic of x is x⁸), dating from a time when powers were written out in words rather than as superscript numbers. This term was suggested by Robert Recorde, a 16th-century Welsh writer of popular mathematics textbooks, in his 1557 work The Whetstone of Witte (although his spelling was zenzizenzizenzike); he wrote that it "doeth represent the square of squares squaredly".

At the time Recorde proposed this notation, there was no easy way of denoting the powers of numbers other than squares and cubes. The root word for Recorde's notation is zenzic, which is a German spelling of the medieval Italian word censo, meaning "squared". Since the square of a square of a number is its fourth power, Recorde used the word zenzizenzic (spelled by him as zenzizenzike) to express it. Some of the terms had prior use in Latin "zenzicubicus", "zensizensicus" and "zensizenzum". Similarly, as the sixth power of a number is equal to the square of its cube, Recorde used the word zenzicubike to express it; a more modern spelling, zenzicube, is found in Samuel Jeake's Logisticelogia. Finally, the word zenzizenzizenzic denotes the square of the square of a number's square, which is its eighth power: in modern notation,

${\displaystyle x^{8}=\left(\left(x^{2}\right)^{2}\right)^{2}.}$

Recorde proposed three mathematical terms by which any power (that is, index or exponent) greater than 1 could be expressed: zenzic, i.e. squared; cubic; and sursolid, i.e. raised to a prime number greater than three, the smallest of which is five. Sursolids were as follows: 5 was the first; 7, the second; 11, the third; 13, the fourth; etc.

Therefore, a number raised to the power of six would be zenzicubic, a number raised to the power of seven would be the second sursolid, hence bissursolid (not a multiple of two and three), a number raised to the twelfth power would be the "zenzizenzicubic" and a number raised to the power of ten would be the square of the (first) sursolid. The fourteenth power was the square of the second sursolid, and the twenty-second was the square of the third sursolid.

Curiously, Jeake's text appears to designate a written exponent of 0 as being equal to an "absolute number, as if it had no Mark", thus using the notation x⁰ to refer to x alone, while a written exponent of 1, in his text, denotes "the Root of any number", thus using the notation x¹ to refer to what is now known to be x^0.5.

The word, as well as the system, is obsolete except as a curiosity; the Oxford English Dictionary (OED) has only one citation for it. As well as being a mathematical oddity, it survives as a linguistic oddity: zenzizenzizenzic has more Zs than any other word in the OED.

Samuel Jeake the Younger gives zenzizenzizenzizenzike (the square of the square of the square of the square, or 16th power) in a table in A Compleat Body of Arithmetick:

🔗 Video games 🔗 Molecular Biology 🔗 Video games/Sega 🔗 Molecular Biology/Molecular and Cell Biology 🔗 Molecular Biology/Genetics 🔗 Molecular Biology/Cell Signaling

Sonic hedgehog protein (SHH) is encoded for by the SHH gene. The protein is named after the character Sonic the Hedgehog.

This signaling molecule is key in regulating embryonic morphogenesis in all animals. SHH controls organogenesis and the organization of the central nervous system, limbs, digits and many other parts of the body. Sonic hedgehog is a morphogen that patterns the developing embryo using a concentration gradient characterized by the French flag model. This model has a non-uniform distribution of SHH molecules which governs different cell fates according to concentration. Mutations in this gene can cause holoprosencephaly, a failure of splitting in the cerebral hemispheres, as demonstrated in an experiment using SHH knock-out mice in which the forebrain midline failed to develop and instead only a single fused telencephalic vesicle resulted.

Sonic hedgehog still plays a role in differentiation, proliferation, and maintenance of adult tissues. Abnormal activation of SHH signaling in adult tissues has been implicated in various types of cancers including breast, skin, brain, liver, gallbladder and many more.

🔗 Aviation 🔗 Aviation/aircraft 🔗 Aviation/rotorcraft

The cyclogyro, or cyclocopter, is an aircraft configuration that uses a horizontal-axis cyclorotor as a rotor wing to provide lift and sometimes also propulsion and control. In principle, the cyclogyro is capable of vertical take off and landing and hovering performance like a helicopter, while potentially benefiting from some of the advantages of a fixed-wing aircraft.

The cyclogyro is distinct from the Flettner airplane which uses a cylindrical wing rotor to harness the Magnus effect.

🔗 Mathematics

An untouchable number is a positive integer that cannot be expressed as the sum of all the proper divisors of any positive integer (including the untouchable number itself). That is, these numbers are not in the image of the aliquot sum function. Their study goes back at least to Abu Mansur al-Baghdadi (circa 1000 AD), who observed that both 2 and 5 are untouchable.

🔗 Poetry 🔗 Songs

"Desiderata" (Latin: "things desired") is an early 1920s prose poem by the American writer Max Ehrmann. Although he copyrighted it in 1927, he distributed copies of it without a required copyright notice during 1933 and c. 1942, thereby forfeiting his US copyright. Largely unknown in the author's lifetime, its use in devotional and spoken word recordings in 1960 and 1971 called it to the attention of the world.

🔗 Russia 🔗 Russia/technology and engineering in Russia 🔗 Spaceflight 🔗 Europe 🔗 China 🔗 Russia/science and education in Russia 🔗 Europe/ESA 🔗 Solar System/Mars 🔗 Solar System

The Mars-500 mission was a psychosocial isolation experiment conducted between 2007 and 2011 by Russia, the European Space Agency and China, in preparation for an unspecified future crewed spaceflight to the planet Mars. The experiment's facility was located at the Russian Academy of Sciences' Institute of Biomedical Problems (IBMP) in Moscow, Russia.

Between 2007 and 2011, three different crews of volunteers lived and worked in a mock-up spacecraft at IBMP. The final stage of the experiment, which was intended to simulate a 520-day crewed mission, was conducted by an all-male crew consisting of three Russians (Alexey Sitev, Sukhrob Kamolov, Alexander Smoleevskij), a Frenchman (Romain Charles), an Italian (Diego Urbina) and a Chinese citizen (Yue Wang). The mock-up facility simulated an Earth-Mars shuttle spacecraft, an ascent-descent craft, and the Martian surface. The volunteers who participated in the three stages included professionals with experience in engineering, medicine, biology, and human spaceflight. The experiment yielded important data on the physiological, social and psychological effects of long-term close-quarters isolation.

🔗 Ships

The Voith Schneider propeller (VSP), also known as a cycloidal drive is a specialized marine propulsion system (MPS). It is highly maneuverable, being able to change the direction of its thrust almost instantaneously. It is widely used on tugs and ferries.