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🔗 Africa 🔗 Egypt 🔗 Africa/Sudan

Bir Tawil (Egyptian Arabic: بير طويل, romanized: Bīr Ṭawīl, lit. 'tall water well', [biːɾ tˤɑˈwiːl]) is a 2,060 km² (795.4 sq mi) area of land along the border between Egypt and Sudan, which is uninhabited and claimed by neither country. When spoken of in association with the neighbouring Halaib Triangle, it is sometimes referred to as the Bir Tawil Triangle, despite the area's quadrilateral shape; the two "triangles" border at a quadripoint.

Its terra nulliuscode: lat promoted to code: la status results from a discrepancy between the straight political boundary between Egypt and Sudan established in 1899, and the irregular administrative boundary established in 1902. Egypt asserts the political boundary, and Sudan asserts the administrative boundary, with the result that the Hala'ib Triangle is claimed by both and Bir Tawil by neither. In 2014, author Alastair Bonnett described Bir Tawil as the only place on Earth that was habitable but was not claimed by any recognised government.

The Electro Gyro-Cator was claimed to be the world's first automated commercially available automotive navigation system. It was co-developed by Honda, Alpine, and Stanley Electric Co..

Unlike most navigation systems of today, it did not use GPS Satellites to maintain its position and discern movement of the vehicle. Rather, it was an Inertial navigation system, because it contained a helium gas gyroscope that could detect both rotation and movement. A special servo gear was also attached to the transmission housing to feed information to the Gyro-Cator to help maintain position, map speed and distance traveled.

Transparent maps were placed inside the unit and it would scroll them past a 6 inch monochrome CRT illuminated screen as the car traveled along. The monitor would indicate by a series of circles (or cross hairs) on the screen to show the vehicle's current location or display lines for path of travel. A marking pen was also included to help make personal indicators on the map if needed. Adjustments could be made to change the display scale, position, rotation, brightness, and contrast. In its only year of production in 1981, it was announced as an option on that year's Honda Accord and Honda Vigor, but at ¥300,000 ($2,746 USD), it was almost a quarter of the value of the car. It is not clear how many units were actually sold to customers as a "dealer option". A patent for gyroscope design was introduced to the US in design patent D274332.

Documented weight for the unit was roughly 20 lb (9 kg). A display unit, with a cutaway of the Gyroscope, is currently shown at the Honda Collection Hall at Twin Ring Motegi, Japan.

🔗 Apple Inc. 🔗 Computing 🔗 Computing/Software

Contiki is an operating system for networked, memory-constrained systems with a focus on low-power wireless Internet of Things (IoT) devices. Extant uses for Contiki include systems for street lighting, sound monitoring for smart cities, radiation monitoring, and alarms. It is open-source software released under the BSD-3-Clause license.

Contiki was created by Adam Dunkels in 2002 and has been further developed by a worldwide team of developers from Texas Instruments, Atmel, Cisco, ENEA, ETH Zurich, Redwire, RWTH Aachen University, Oxford University, SAP, Sensinode, Swedish Institute of Computer Science, ST Microelectronics, Zolertia, and many others. Contiki gained popularity because of its built in TCP/IP stack and lightweight preemptive scheduling over event-driven kernel which is a very motivating feature for IoT. The name Contiki comes from Thor Heyerdahl's famous Kon-Tiki raft.

Contiki provides multitasking and a built-in Internet Protocol Suite (TCP/IP stack), yet needs only about 10 kilobytes of random-access memory (RAM) and 30 kilobytes of read-only memory (ROM). A full system, including a graphical user interface, needs about 30 kilobytes of RAM.

A new branch has recently been created, known as Contiki-NG: The OS for Next Generation IoT Devices

🔗 United States 🔗 Women's History 🔗 United States/Louisiana 🔗 United States/Franco-Americans

Correction girls was a term describing women who were forcibly shipped from France to its colonies in America as brides for its colonists during the early 18th century.

🔗 France 🔗 Architecture 🔗 Catholicism

The Cathedral of Saint Peter of Beauvais (French: Cathédrale Saint-Pierre de Beauvais) is a Roman Catholic church in the northern town of Beauvais, Oise, France. It is the seat of the Bishop of Beauvais, Noyon and Senlis.

The cathedral is in the Gothic style, and consists of a 13th-century choir, with an apse and seven polygonal apsidal chapels reached by an ambulatory, joined to a 16th-century transept.

It has the highest Gothic choir in the world: (48.50 m) under vault. From 1569 to 1573 the cathedral of Beauvais was, with its tower of 153 meters, the highest human construction of the world. Its designers had the ambition to make it the largest gothic cathedral in France ahead of Amiens. Victim of two collapses, one in the 13th century, the other in the 16th century, it remains unfinished today; only the choir and the transept have been built.

The planned nave of the cathedral was never constructed. The remnant of the previous 10th-century Romanesque cathedral, known as the Basse Œuvre ("Lower Work"), still occupies the intended site of the nave.

🔗 Agriculture 🔗 Food and drink 🔗 Birds 🔗 Agriculture/Livestock

The Silkie (also known as the Silky or Chinese silk chicken) is a breed of chicken named for its atypically fluffy plumage, which is said to feel like silk and satin. The breed has several other unusual qualities, such as black skin and bones, blue earlobes, and five toes on each foot, whereas most chickens only have four. They are often exhibited in poultry shows, and also appear in various colors. In addition to their distinctive physical characteristics, Silkies are well known for their calm, friendly temperament. It is among the most docile of poultry. Hens are also exceptionally broody, and care for young well. Although they are fair layers themselves, laying only about three eggs a week, they are commonly used to hatch eggs from other breeds and bird species due to their broody nature.

🔗 Jazz

The Real Book is a musicians' fake book – a compilation of lead sheets for jazz standards. Fake books had been around at least since the late 1920s, but their organization was haphazard, and their content did not always keep pace with contemporary musical styles. The Real Book was initially produced by two students at the Berklee College of Music in the 1970s, as an updated fake book. It became so popular that the books was eventually "legitimized" by publisher Hal Leonard, and re-released in a series of editions and transpositions for various instruments.

The Thomas of Cana copper plates (Malayalam: Knai Thoma Cheppedu), or Knanaya copper plates, dated variously between 345 C.E. and 811 C.E., are a lost set of copper-plate grants issued by the unidentified Chera/Perumal king of Kerala "Co-qua-rangon" to Syriac Christian merchants led by Knai Thoma (anglicized as Thomas of Cana) in the city of "Makotayar Pattinam" (present day Kodungallur), south India. The royal charters were reportedly engraved in ”Malabar”, Chaldean and Arabic on both sides of two copper plates (joined by a ring). Archbishop Francis Ros notes in his 1604 account M.S. ADD 9853 that the plates were taken to Portugal by the Franciscan Order.

Scholar M.G.S. Narayanan tentatively identifies king “Co-qua-rangon” with king Rama Rajasekhara (Co-qua-rangon → Ko Kotai Iraman → Rajadhiraja Rama) of the 9th century Chera Empire.

The Knanaya or the people of Knai Thoma were historically associated with the southern portion of the Chera/Perumal headquarters Kodungallur until in 1524 they were dispersed from the city due to conflict between the Kingdom of Cochin and the Kingdom of Calicut. The plate was cherished by the Knanaya as evidence of their arrival in Kerala under the leadership of Knai Thoma as well as a notation of the historical, economic, and social rights bestowed upon them by the Chera Perumal. The native Christian tradition places the arrival of Thomas of Cana in 345 C.E.

Translations of the existing Kollam Syrian Plates of the 9th century made by the Syrian Christian priest Ittimani in 1601 as well as the French Indologist Abraham Anquetil Duperron in 1758 both note that the one of the plates mentioned a brief of the arrival of Knai Thoma.It is believed that this was a notation of the previous rights bestowed upon the Christians by Cheraman Perumal. The contemporary set however does not mention this paragraph and is believed to be incomplete or a later inscription. Scholar of Early Christian history István Percvel theorizes that at one time the Kollam Syrian plates and the Thomas of Cana plates were kept together.

🔗 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.

🔗 Computer science

In computer science, the maximum sum subarray problem, also known as the maximum segment sum problem, is the task of finding a contiguous subarray with the largest sum, within a given one-dimensional array A[1...n] of numbers. Formally, the task is to find indices ${\displaystyle i}$ and ${\displaystyle j}$ with ${\displaystyle 1\leq i\leq j\leq n}$, such that the sum

${\displaystyle \sum _{x=i}^{j}A[x]}$

is as large as possible. (Some formulations of the problem also allow the empty subarray to be considered; by convention, the sum of all values of the empty subarray is zero.) Each number in the input array A could be positive, negative, or zero.

For example, for the array of values [−2, 1, −3, 4, −1, 2, 1, −5, 4], the contiguous subarray with the largest sum is [4, −1, 2, 1], with sum 6.

Some properties of this problem are:

1. If the array contains all non-negative numbers, then the problem is trivial; a maximum subarray is the entire array.
2. If the array contains all non-positive numbers, then a solution is any subarray of size 1 containing the maximal value of the array (or the empty subarray, if it is permitted).
3. Several different sub-arrays may have the same maximum sum.

This problem can be solved using several different algorithmic techniques, including brute force, divide and conquer, dynamic programming, and reduction to shortest paths.