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Khaled El-Masri (also Khalid El-Masri and Khaled Masri, Levantine Arabic pronunciation: [ˈxaːlɪd elˈmɑsˤɾi, -ˈmɑsˤɾe], Arabic: خالد المصري‎) (born 29 June 1963) is a German and Lebanese citizen who was mistakenly abducted by the Macedonian police in 2003, and handed over to the U.S. Central Intelligence Agency (CIA). While in CIA custody, he was flown to Afghanistan, where he was held at a black site and routinely interrogated, beaten, strip-searched, sodomized, and subjected to other cruel forms of inhumane and degrading treatment and torture. After El-Masri held hunger strikes, and was detained for four months in the "Salt Pit", the CIA finally admitted his arrest and torture were a mistake and released him. He is believed to be among an estimated 3,000 detainees whom the CIA abducted from 2001–2005.

In May 2004, the U.S. Ambassador to Germany, Daniel R. Coats, convinced the German interior minister, Otto Schily, not to press charges or to reveal the program. El-Masri filed suit against the CIA for his arrest, extraordinary rendition and torture. In 2006, his suit El Masri v. Tenet, in which he was represented by the American Civil Liberties Union (ACLU), was dismissed by the United States District Court for the Eastern District of Virginia, based on the U.S. government's claiming the state secrets privilege. The ACLU said the Bush administration attempted to shield its abuses by invoking this privilege. The case was also dismissed by the Appeals Court for the Fourth Circuit, and in December 2007, the United States Supreme Court declined to hear the case.

On 13 December 2012, El-Masri won an Article 34 case at the European Court of Human Rights in Strasbourg. The court determined he had been tortured while held by CIA agents and ruled that Macedonia was responsible for abusing him while in the country, and knowingly transferring him to the CIA when torture was a possibility. It awarded him compensation. This marked the first time that CIA activities against detainees was legally declared as torture. The European Court condemned nations for collaborating with the United States in these secret programs.

The Hofmeister kink (sometimes also translated Hofmeister kick, German: Hofmeister-Knick) is an automotive design feature seen on modern BMWs and automobiles by other manufacturers. The feature consists of a low forward bend at the C-pillar or D-pillar in the case of touring vehicles or SUVs. It is named for Wilhelm Hofmeister, BMW design chief from 1955-1970.

Among the first cars to feature this design trait were some 1949 General Motors 2-door cars, as well as the 1958 Lancia Flaminia Sport Zagato and the 1961 Lancia Flavia Coupé. Despite its being used broadly across automotive makes, the term "Hofmeister kink" is generally used in reference to automobiles designed by BMW it later appeared in.

The first BMWs to feature it were the BMW 3200 CS and the BMW 1500 shown at the Frankfurt Motor Show in September 1961 and was later named after then-BMW director of design, Wilhelm Hofmeister. In early models, the widened base of the C-pillar sometimes featured the BMW roundel.

Apart from its stylistic effect, the Hofmeister kink is said by BMW to suggest that all BMW models have rear-wheel drive (or all-wheel drive biased to the rear).

Not unique to BMW models, similar C-pillar kinks have appeared on cars of other brands both before 1961 and since. For example, the 1951 Kaiser Deluxe Golden Dragon shows a considerable "Hofmeister kink" in its greenhouse design. Another instance is seen with the 1994 Chevrolet Impala SS, based on the 1991+ Chevrolet Caprice, which had a plastic C-pillar kink insert and unique quarter window added to its design for its debut year. For 1994, the Caprice retained the standard triangular shaped window glass. In 1995, GM did away with the plastic insert, and incorporated this kink into the stamped sheetmetal quarter panels themselves for both the Impala SS as well as the Caprice Classic. In addition, the kink is present on some Honda Accord and Civic models.

Unlambda is a minimal, "nearly pure" functional programming language invented by David Madore. It is based on combinatory logic, an expression system without the lambda operator or free variables. It relies mainly on two built-in functions (s and k) and an apply operator (written `, the backquote character). These alone make it Turing-complete, but there are also some input/output (I/O) functions to enable interacting with the user, some shortcut functions, and a lazy evaluation function. Variables are unsupported.

Unlambda is free and open-source software distributed under a GNU General Public License (GPL) 2.0 or later.

Atmos is the brand name of a mechanical torsion pendulum clock manufactured by Jaeger-LeCoultre in Switzerland which does not need to be wound manually. It gets the energy it needs to run from temperature and atmospheric pressure changes in the environment, and can run for years without human intervention.

The clock is driven by a mainspring, which is wound by the expansion and contraction of liquid and gaseous ethyl chloride in an internal hermetically sealed bellows. The ethyl chloride vaporises into an expansion chamber as the temperature rises, compressing a spiral spring; with a fall in temperature the gas condenses and the spring slackens. This motion constantly winds the mainspring. A temperature variation of only one degree in the range between 15 °C (59 °F) and 30 °C (86 °F), or a pressure variation of 3 mmHg, is sufficient for two days' operation.

In order to run the clock on this small amount of energy, everything inside the Atmos has to work in as friction-free a manner as possible. For timekeeping it uses a torsion pendulum, which consumes less energy than an ordinary pendulum. The torsion pendulum has a period of precisely one minute; thirty seconds to rotate in one direction and thirty seconds to return to the starting position. This is thirty times slower than the 0.994 m (39.1 in) seconds pendulum typically found in a longcase clock, where each swing (or half-period) takes one second.

Pearson hashing is a hash function designed for fast execution on processors with 8-bit registers. Given an input consisting of any number of bytes, it produces as output a single byte that is strongly dependent on every byte of the input. Its implementation requires only a few instructions, plus a 256-byte lookup table containing a permutation of the values 0 through 255.

This hash function is a CBC-MAC that uses an 8-bit substitution cipher implemented via the substitution table. An 8-bit cipher has negligible cryptographic security, so the Pearson hash function is not cryptographically strong, but it is useful for implementing hash tables or as a data integrity check code, for which purposes it offers these benefits:

• It is extremely simple.
• It executes quickly on resource-limited processors.
• There is no simple class of inputs for which collisions (identical outputs) are especially likely.
• Given a small, privileged set of inputs (e.g., reserved words for a compiler), the permutation table can be adjusted so that those inputs yield distinct hash values, producing what is called a perfect hash function.
• Two input strings differing by exactly one character never collide. E.g., applying the algorithm on the strings ABC and AEC will never produce the same value.

One of its drawbacks when compared with other hashing algorithms designed for 8-bit processors is the suggested 256 byte lookup table, which can be prohibitively large for a small microcontroller with a program memory size on the order of hundreds of bytes. A workaround to this is to use a simple permutation function instead of a table stored in program memory. However, using a too simple function, such as T[i] = 255-i, partly defeats the usability as a hash function as anagrams will result in the same hash value; using a too complex function, on the other hand, will affect speed negatively. Using a function rather than a table also allows extending the block size. Such functions naturally have to be bijective, like their table variants.

The algorithm can be described by the following pseudocode, which computes the hash of message C using the permutation table T:

algorithm pearson hashing is
    h := 0

    for each c in C loop
        h := T[ h xor c ]
    end loop

    return h

The hash variable (h) may be initialized differently, e.g. to the length of the data (C) modulo 256; this particular choice is used in the Python implementation example below.

An emirp (prime spelled backwards) is a prime number that results in a different prime when its decimal digits are reversed. This definition excludes the related palindromic primes. The term reversible prime is used to mean the same as emirp, but may also, ambiguously, include the palindromic primes.

The sequence of emirps begins 13, 17, 31, 37, 71, 73, 79, 97, 107, 113, 149, 157, 167, 179, 199, 311, 337, 347, 359, 389, 701, 709, 733, 739, 743, 751, 761, 769, 907, 937, 941, 953, 967, 971, 983, 991, ... (sequence A006567 in the OEIS).

All non-palindromic permutable primes are emirps.

As of November 2009, the largest known emirp is 10¹⁰⁰⁰⁶+941992101×10⁴⁹⁹⁹+1, found by Jens Kruse Andersen in October 2007.

The term 'emirpimes' (singular) is used also in places to treat semiprimes in a similar way. That is, an emirpimes is a semiprime that is also a (distinct) semiprime upon reversing its digits.

The reflected binary code (RBC), also known just as reflected binary (RB) or Gray code after Frank Gray, is an ordering of the binary numeral system such that two successive values differ in only one bit (binary digit). The reflected binary code was originally designed to prevent spurious output from electromechanical switches. Today, Gray codes are widely used to facilitate error correction in digital communications such as digital terrestrial television and some cable TV systems.

N8VEM was a homebrew computing project. It featured a variety of free and open hardware and software. N8VEM builders made their own homebrew computer systems for themselves and shared their experiences with other homebrew computer hobbyists. N8VEM homebrew computer components are made in the style of vintage computers of the mid to late 1970s and early 1980s using a mix of classic and modern technologies. They are designed with ease of amateur assembly in mind.

In November 2015 the N8VEM project was ended by its creator Andrew Lynch and the community reconvened under the new name of Retrobrew Computers.

A quasiperiodic crystal, or quasicrystal, is a structure that is ordered but not periodic. A quasicrystalline pattern can continuously fill all available space, but it lacks translational symmetry. While crystals, according to the classical crystallographic restriction theorem, can possess only two-, three-, four-, and six-fold rotational symmetries, the Bragg diffraction pattern of quasicrystals shows sharp peaks with other symmetry orders—for instance, five-fold.

Aperiodic tilings were discovered by mathematicians in the early 1960s, and, some twenty years later, they were found to apply to the study of natural quasicrystals. The discovery of these aperiodic forms in nature has produced a paradigm shift in the fields of crystallography. Quasicrystals had been investigated and observed earlier, but, until the 1980s, they were disregarded in favor of the prevailing views about the atomic structure of matter. In 2009, after a dedicated search, a mineralogical finding, icosahedrite, offered evidence for the existence of natural quasicrystals.

Roughly, an ordering is non-periodic if it lacks translational symmetry, which means that a shifted copy will never match exactly with its original. The more precise mathematical definition is that there is never translational symmetry in more than n – 1 linearly independent directions, where n is the dimension of the space filled, e.g., the three-dimensional tiling displayed in a quasicrystal may have translational symmetry in two directions. Symmetrical diffraction patterns result from the existence of an indefinitely large number of elements with a regular spacing, a property loosely described as long-range order. Experimentally, the aperiodicity is revealed in the unusual symmetry of the diffraction pattern, that is, symmetry of orders other than two, three, four, or six. In 1982 materials scientist Dan Shechtman observed that certain aluminium-manganese alloys produced the unusual diffractograms which today are seen as revelatory of quasicrystal structures. Due to fear of the scientific community's reaction, it took him two years to publish the results for which he was awarded the Nobel Prize in Chemistry in 2011. On 25 October 2018, Luca Bindi and Paul Steinhardt were awarded the Aspen Institute 2018 Prize for collaboration and scientific research between Italy and the United States.

Butterfly gardening is a way to create, improve, and maintain habitat for lepidopterans including butterflies, skippers, and moths. Butterflies have four distinct life stages—egg, larva, chrysalis, and adult. In order to support and sustain butterfly populations, an ideal butterfly garden contains habitat for each life stage.

Butterfly larvae, with some exceptions such as the carnivorous harvester (Feniseca tarquinius), consume plant matter and can be generalists or specialists. While butterflies like the painted lady (Vanessa cardui) are known to consume over 200 plants as caterpillars, other species like the monarch (Danaus plexippus), and the regal fritillary (Speyeria idalia) only consume plants in one genus, milkweed and violets, respectively.

As adults, butterflies feed mainly on nectar, but they have also evolved to consume rotting fruit, tree sap, and even carrion. Supporting nectarivorous adult butterflies involves planting nectar plants of different heights, color, and bloom times. Butterfly bait stations can easily be made to provide a food source for species that prefer fruit and sap. In addition to food sources, windbreaks in the form of trees and shrubs shelter butterflies and can provide larval food and overwintering grounds. "Puddling" is a behavior generally done by male butterflies in which they gather to drink nutrients and water and incorporating a puddling ground for butterflies will enhance a butterfly garden. While butterflies are not the only pollinator, creating butterfly habitat also creates habitat for bees, beetles, flies, and other pollinators