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🔗 Mathematics

In geometry, circle packing is the study of the arrangement of circles (of equal or varying sizes) on a given surface such that no overlapping occurs and so that no circle can be enlarged without creating an overlap. The associated packing density, η, of an arrangement is the proportion of the surface covered by the circles. Generalisations can be made to higher dimensions – this is called sphere packing, which usually deals only with identical spheres.

While the circle has a relatively low maximum packing density of 0.9069 on the Euclidean plane, it does not have the lowest possible. The "worst" shape to pack onto a plane is not known, but the smoothed octagon has a packing density of about 0.902414, which is the lowest maximum packing density known of any centrally-symmetric convex shape. Packing densities of concave shapes such as star polygons can be arbitrarily small.

The branch of mathematics generally known as "circle packing" is concerned with the geometry and combinatorics of packings of arbitrarily-sized circles: these give rise to discrete analogs of conformal mapping, Riemann surfaces and the like.

🔗 United States/U.S. Government 🔗 United States 🔗 Mass surveillance 🔗 Espionage 🔗 Cryptography 🔗 Cryptography/Computer science 🔗 United States/Utah

The Utah Data Center (UDC), also known as the Intelligence Community Comprehensive National Cybersecurity Initiative Data Center, is a data storage facility for the United States Intelligence Community that is designed to store data estimated to be on the order of exabytes or larger. Its purpose is to support the Comprehensive National Cybersecurity Initiative (CNCI), though its precise mission is classified. The National Security Agency (NSA) leads operations at the facility as the executive agent for the Director of National Intelligence. It is located at Camp Williams near Bluffdale, Utah, between Utah Lake and Great Salt Lake and was completed in May 2019 at a cost of $1.5 billion.

The Utah Data Center, code-named Bumblehive, is the first Intelligence Community Comprehensive National Cyber-security Initiative (IC CNCI) data center designed to support the US intelligence community. The "massive data repository" is designed to cope with the large increase in digital data that has accompanied the rise of the global internet.

🔗 California 🔗 Environment 🔗 Terrorism 🔗 Agriculture

In 1989, a sudden invasion of Mediterranean fruit flies (Ceratitis capitata, "medflies") appeared in California and began devastating crops. Scientists were puzzled and said that the sudden appearance of the insects "defies logic", and some speculated "biological terrorists" were responsible. Analysis suggested that an outside hand played a role in the dense infestation.

A person or group calling itself "The Breeders" took responsibility for the bioterrorist attack, as financial retaliation for the environmental damage caused by the state's Malathion aerial spraying; the group's members were never identified. Subsequently, three months after "The Breeders" announced the medfly release, the state ended its decade-long Malathion program and sought alternate ways to handle destructive insects.

🔗 Medicine 🔗 Viruses

Variolation or inoculation was the method first used to immunize an individual against smallpox (Variola) with material taken from a patient or a recently variolated individual, in the hope that a mild, but protective, infection would result. The procedure was most commonly carried out by inserting/rubbing powdered smallpox scabs or fluid from pustules into superficial scratches made in the skin. The patient would develop pustules identical to those caused by naturally occurring smallpox, usually producing a less severe disease than naturally acquired smallpox. Eventually, after about two to four weeks, these symptoms would subside, indicating successful recovery and immunity. The method was first used in China and the Middle East before it was introduced into England and North America in the 1720s in the face of some opposition. The method is no longer used today. It was replaced by smallpox vaccine, a safer alternative. This in turn led to the development of the many vaccines now available against other diseases.

🔗 Education

Underwater basket weaving is an idiom referring pejoratively to supposedly useless or absurd college or university courses and often generally to refer to a perceived decline in educational standards.

The term also serves as an intentionally humorous generic answer to questions about an academic degree. It is also used to humorously refer to any non-academic elective course, specifically one that does not count towards any graduation requirements.

🔗 Computing 🔗 Computer science 🔗 C/C++ 🔗 C/C++/C

In the C programming language, Duff's device is a way of manually implementing loop unrolling by interleaving two syntactic constructs of C: the do-while loop and a switch statement. Its discovery is credited to Tom Duff in November 1983, when Duff was working for Lucasfilm and used it to speed up a real-time animation program.

Loop unrolling attempts to reduce the overhead of conditional branching needed to check whether a loop is done, by executing a batch of loop bodies per iteration. To handle cases where the number of iterations is not divisible by the unrolled-loop increments, a common technique among assembly language programmers is to jump directly into the middle of the unrolled loop body to handle the remainder. Duff implemented this technique in C by using C's case label fall-through feature to jump into the unrolled body.

🔗 California 🔗 California/Los Angeles area

Skid Row is a neighborhood in Downtown Los Angeles. The area is also known as Central City East.

As of a 2019 count, the population of the district was 4,757. Skid Row contains one of the largest stable populations (about 2,783) of homeless people in the United States and has been known for its condensed homeless population since the 1930s. Its long history of police raids, targeted city initiatives, and homelessness advocacy make it one of the most notable districts in Los Angeles.

Covering fifty city blocks (2.71 sq mi) immediately east of downtown Los Angeles, Skid Row is bordered by Third Street to the north, Seventh Street to the south, Alameda Street to the east, and Main Street to the west.

🔗 Animal anatomy 🔗 Neuroscience 🔗 Animals

The following are two lists of animals ordered by the size of their nervous system. The first list shows number of neurons in their entire nervous system, indicating their overall neural complexity. The second list shows the number of neurons in the structure that has been found to be representative of animal intelligence. The human brain contains 86 billion neurons, with 16 billion neurons in the cerebral cortex.

🔗 Dogs 🔗 Psychology

Intelligent disobedience occurs where a service animal trained to help a disabled person goes directly against the owner's instructions in an effort to make a better decision. This behavior is a part of the dog's training and is central to a service animal's success on the job. The concept of intelligent disobedience has been in use and a common part of service animals' training since at least 1936.

🔗 Business

Founder's syndrome (also founderitis) is the difficulty faced by organizations where one or more founders maintain disproportionate power and influence following the effective initial establishment of the project, leading to a wide range of problems for the organization. The passion and charisma of the founder(s), sources of the initial creativity and productivity of the organization, become limiting or destructive factors. The syndrome occurs in both non-profit and for-profit organizations. It may simply limit further growth and success of the project, or it may lead to bitter factionalism and divisions as the scale of demands made on the organization increases, or it may result in outright failure. There are ways in which a founder or organization can respond and grow beyond this situation.