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πŸ”— DNA origami

πŸ”— Biology πŸ”— Molecular and Cell Biology πŸ”— Genetics

DNA origami is the nanoscale folding of DNA to create non-arbitrary two- and three-dimensional shapes at the nanoscale. The specificity of the interactions between complementary base pairs make DNA a useful construction material, through design of its base sequences. DNA is a well-understood material that is suitable for creating scaffolds that hold other molecules in place or to create structures all on its own.

DNA origami was the cover story of Nature on March 16, 2006. Since then, DNA origami has progressed past an art form and has found a number of applications from drug delivery systems to uses as circuitry in plasmonic devices; however, most applications remain in a concept or testing phase.

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πŸ”— Gimli Glider

πŸ”— Aviation πŸ”— Disaster management πŸ”— Aviation/Aviation accident πŸ”— Canada πŸ”— Aviation/aircraft πŸ”— Aviation/gliding πŸ”— Canada/History of Canada πŸ”— Canada/Manitoba

Air Canada FlightΒ 143 was a Canadian scheduled domestic passenger flight between Montreal and Edmonton that ran out of fuel on JulyΒ 23, 1983, at an altitude of 41,000 feet (12,000Β m), midway through the flight. The crew was able to glide the Boeing 767 aircraft safely to an emergency landing at a former Royal Canadian Air Force base in Gimli, Manitoba, that had been turned into a motor racing track. This unusual aviation incident earned the aircraft the nickname "Gimli Glider".

The subsequent investigation revealed that a combination of company failures, human errors and confusion over unit measures had led to the aircraft being refuelled with insufficient fuel for the planned flight.

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πŸ”— Bookland

πŸ”— Books

"Bookland" is the informal name for the Unique Country Code (UCC) prefix allocated in the 1980s for European Article Number (EAN) identifiers of published books, regardless of country of origin, so that the EAN namespace can catalogue books by ISBN rather than maintaining a redundant parallel numbering system. In other words, Bookland is a fictitious country that exists solely in EAN for the purposes of non-geographically cataloguing books in the otherwise geographically keyed EAN coding system.

πŸ”— The Magical Number 7 plus or minus 2

πŸ”— Computing πŸ”— Psychology πŸ”— Usability

"The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information" is one of the most highly cited papers in psychology. It was published in 1956 in Psychological Review by the cognitive psychologist George A. Miller of Harvard University's Department of Psychology. It is often interpreted to argue that the number of objects an average human can hold in short-term memory is 7 Β± 2. This has occasionally been referred to as Miller's law.

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πŸ”— Cool stuff you can do with netcat

πŸ”— Computing πŸ”— Computing/Software πŸ”— Computing/Free and open-source software

netcat (often abbreviated to nc) is a computer networking utility for reading from and writing to network connections using TCP or UDP. The command is designed to be a dependable back-end that can be used directly or easily driven by other programs and scripts. At the same time, it is a feature-rich network debugging and investigation tool, since it can produce almost any kind of connection its user could need and has a number of built-in capabilities.

Its list of features includes port scanning, transferring files, and port listening, and it can be used as a backdoor.

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πŸ”— 1961 Goldsboro B-52 crash

πŸ”— United States πŸ”— United States/North Carolina πŸ”— Aviation πŸ”— Military history πŸ”— Disaster management πŸ”— Military history/Military aviation πŸ”— Military history/North American military history πŸ”— Military history/United States military history πŸ”— United States/Military history - U.S. military history πŸ”— Aviation/Aviation accident πŸ”— Military history/Military science, technology, and theory πŸ”— Military history/Weaponry

The 1961 Goldsboro B-52 crash was an accident that occurred near Goldsboro, North Carolina, on 23 January 1961. A Boeing B-52 Stratofortress carrying two 3–4-megaton Mark 39 nuclear bombs broke up in mid-air, dropping its nuclear payload in the process. The pilot in command, Walter Scott Tulloch, ordered the crew to eject at 9,000 feet (2,700Β m). Five crewmen successfully ejected or bailed out of the aircraft and landed safely, another ejected, but did not survive the landing, and two died in the crash. Information declassified in 2013 showed that one of the bombs came very close to detonating.

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πŸ”— Burned house horizon

πŸ”— History πŸ”— Europe πŸ”— Ukraine πŸ”— Archaeology πŸ”— Romania πŸ”— Moldova

In the archaeology of Neolithic Europe, the burned house horizon is the geographical extent of the phenomenon of presumably intentionally burned settlements.

This was a widespread and long-lasting tradition in what is now Southeastern and Eastern Europe, lasting from as early as 6500 BCE (the beginning of the Neolithic) to as late as 2000 BCE (the end of the Chalcolithic and the beginning of the Bronze Age). A notable representative of this tradition is the Cucuteni-Trypillian culture, which was centered on the burned-house horizon both geographically and temporally.

There is still a discussion in the study of Neolithic and Eneolithic Europe whether the majority of burned houses were intentionally set alight or not.

Although there is still debate about the why house burning was practiced, the evidence seems to indicate that it was highly unlikely to have been accidental. There is also debate about why this would have been done deliberately and regularly, since these burnings could destroy the entire settlement. However, in recent years, the consensus has begun to gel around the "domicide" theory supported by Tringham, Stevanovic and others.

Cucuteni-Trypillian settlements were completely burned every 75–80 years, leaving behind successive layers consisting mostly of large amounts of rubble from the collapsed wattle-and-daub walls. This rubble was mostly ceramic material that had been created as the raw clay used in the daub of the walls became vitrified from the intense heat that would have turned it a bright orange color during the conflagration that destroyed the buildings, much the same way that raw clay objects are turned into ceramic products during the firing process in a kiln. Moreover, the sheer amount of fired-clay rubble found within every house of a settlement indicates that a fire of enormous intensity would have raged through the entire community to have created the volume of material found.

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πŸ”— The German tank problem

πŸ”— Mathematics πŸ”— Germany πŸ”— Military history πŸ”— Statistics πŸ”— Military history/Intelligence πŸ”— Military history/World War II πŸ”— Military history/German military history πŸ”— Military history/European military history

In the statistical theory of estimation, the German tank problem consists of estimating the maximum of a discrete uniform distribution from sampling without replacement. In simple terms, suppose we have an unknown number of items which are sequentially numbered from 1 to N. We take a random sample of these items and observe their sequence numbers; the problem is to estimate N from these observed numbers.

The problem can be approached using either frequentist inference or Bayesian inference, leading to different results. Estimating the population maximum based on a single sample yields divergent results, whereas estimation based on multiple samples is a practical estimation question whose answer is simple (especially in the frequentist setting) but not obvious (especially in the Bayesian setting).

The problem is named after its historical application by Allied forces in World War II to the estimation of the monthly rate of German tank production from very few data. This exploited the manufacturing practice of assigning and attaching ascending sequences of serial numbers to tank components (chassis, gearbox, engine, wheels), with some of the tanks eventually being captured in battle by Allied forces.

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πŸ”— Buy Nothing Day

πŸ”— United States πŸ”— Marketing & Advertising πŸ”— Retailing πŸ”— Holidays πŸ”— Holidays/Christmas

Buy Nothing Day (BND) is an international day of protest against consumerism. In North America, the United Kingdom, Finland and Sweden, Buy Nothing Day is held the day after U.S. Thanksgiving, concurrent to Black Friday; elsewhere, it is held the following day, which is the last Saturday in November. Buy Nothing Day was founded in Vancouver by artist Ted Dave and subsequently promoted by Adbusters, based in Canada.

The first Buy Nothing Day was organized in Canada in September 1992 "as a day for society to examine the issue of overconsumption." In 1997, it was moved to the Friday after American Thanksgiving, also called "Black Friday", which is one of the ten busiest shopping days in the United States. In 2000, some advertisements by Adbusters promoting Buy Nothing Day were denied advertising time by almost all major television networks except for CNN. Soon, campaigns started appearing in the United States, the United Kingdom, Israel, Austria, Germany, New Zealand, Japan, the Netherlands, France, Norway and Sweden. Participation now includes more than 65 nations.

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