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🔗 Mathematics 🔗 Physics

Stochastic resonance (SR) is a phenomenon where a signal that is normally too weak to be detected by a sensor, can be boosted by adding white noise to the signal, which contains a wide spectrum of frequencies. The frequencies in the white noise corresponding to the original signal's frequencies will resonate with each other, amplifying the original signal while not amplifying the rest of the white noise (thereby increasing the signal-to-noise ratio which makes the original signal more prominent). Further, the added white noise can be enough to be detectable by the sensor, which can then filter it out to effectively detect the original, previously undetectable signal.

This phenomenon of boosting undetectable signals by resonating with added white noise extends to many other systems, whether electromagnetic, physical or biological, and is an area of research.

🔗 Germany 🔗 Africa 🔗 Birds 🔗 European history

The term Pfeilstorch (German for "arrow stork") is given to storks injured by an arrow while wintering in Africa, before returning to Europe with the arrow stuck in their bodies. To date, around 25 Pfeilstörche have been documented.

The first and most famous Pfeilstorch was a white stork found in 1822 near the German village of Klütz, in the state of Mecklenburg-Vorpommern. It was carrying a 30-inch (76 cm) spear from central Africa in its neck. The specimen was stuffed and can be seen today in the zoological collection of the University of Rostock. It is therefore referred to as the Rostocker Pfeilstorch.

This Pfeilstorch was crucial in understanding the migration of European birds. Before migration was understood, people struggled to explain the sudden annual disappearance of birds like the white stork and barn swallow. Besides migration, some theories of the time held that they turned into other kinds of birds, mice, or hibernated underwater during the winter, and such theories were even propagated by zoologists of the time. The Rostocker Pfeilstorch in particular proved that birds migrate long distances to wintering grounds.

🔗 Biography 🔗 Aviation 🔗 Aviation/Aviation accident 🔗 Canada 🔗 Finance & Investment 🔗 Aviation/aerospace biography 🔗 Crime and Criminal Biography 🔗 Crime and Criminal Biography/Organized crime

Kenneth Leishman (June 20, 1931 – December 14, 1979), also known as the Flying Bandit or the Gentleman Bandit was a Canadian criminal responsible for multiple robberies between 1957 and 1966. Leishman was the mastermind behind the largest gold theft in Canadian history. This record stood for over 50 years, until it was surpassed by the Toronto Pearson airport heist in 2023. After being caught and arrested by the Royal Canadian Mounted Police (RCMP), Leishman managed to escape twice, before being caught and serving the remainder of his various sentences.

In December 1979, while flying a Mercy Flight to Thunder Bay, Leishman's aircraft crashed about 40 miles (64 km) north of Thunder Bay.

🔗 Medicine 🔗 Cats 🔗 Microbiology 🔗 Veterinary medicine

Toxoplasma gondii () is a parasitic protozoan (specifically an apicomplexan) that causes toxoplasmosis. Found worldwide, T. gondii is capable of infecting virtually all warm-blooded animals,^: 1 but felids are the only known definitive hosts in which the parasite may undergo sexual reproduction.

In rodents, T. gondii alters behavior in ways that increase the rodents' chances of being preyed upon by felids. Support for this "manipulation hypothesis" stems from studies showing that T. gondii-infected rats have a decreased aversion to cat urine while infection in mice lowers general anxiety, increases explorative behaviors and increases a loss of aversion to predators in general. Because cats are one of the only hosts within which T. gondii can sexually reproduce, such behavioral manipulations are thought to be evolutionary adaptations that increase the parasite's reproductive success since rodents that do not avoid cat habitations will more likely become cat prey. The primary mechanisms of T. gondii–induced behavioral changes in rodents occur through epigenetic remodeling in neurons that govern the relevant behaviors (e.g. hypomethylation of arginine vasopressin-related genes in the medial amygdala, which greatly decrease predator aversion).

In humans, particularly infants and those with weakened immunity, T. gondii infection is generally asymptomatic but may lead to a serious case of toxoplasmosis. T. gondii can initially cause mild, flu-like symptoms in the first few weeks following exposure, but otherwise, healthy human adults are asymptomatic. This asymptomatic state of infection is referred to as a latent infection, and it has been associated with numerous subtle behavioral, psychiatric, and personality alterations in humans. Behavioral changes observed between infected and non-infected humans include a decreased aversion to cat urine (but with divergent trajectories by gender) and an increased risk of schizophrenia. Preliminary evidence has suggested that T. gondii infection may induce some of the same alterations in the human brain as those observed in rodents. Many of these associations have been strongly debated and newer studies have found them to be weak, concluding:

On the whole, there was little evidence that T. gondii was related to increased risk of psychiatric disorder, poor impulse control, personality aberrations, or neurocognitive impairment.

T. gondii is one of the most common parasites in developed countries; serological studies estimate that up to 50% of the global population has been exposed to, and may be chronically infected with, T. gondii; although infection rates differ significantly from country to country. Estimates have shown the highest IgG seroprevalence to be in Ethiopia, at 64.2%, as of 2018.

🔗 California 🔗 Companies 🔗 Technology 🔗 Private Equity 🔗 California/San Francisco Bay Area

Y Combinator is an American seed accelerator launched in March 2005 and has been used to launch over 2,000 companies including Stripe, Airbnb, Cruise Automation, DoorDash, Coinbase, Instacart, and Dropbox. The combined valuation of the top YC companies was over $155 billion as of October, 2019.

🔗 United States/U.S. Government 🔗 United States 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Iran 🔗 Military history/Intelligence 🔗 Military history/Middle Eastern military history

The 1953 Iranian coup d'état, known in Iran as the 28 Mordad coup d'état (Persian: کودتای ۲۸ مرداد), was the overthrow of Prime Minister Mohammad Mosaddegh on 19 August 1953. Led by the Iranian army and supported by the United States and the United Kingdom, the coup aimed at strengthening the autocratic rule of the shah Mohammad Reza Pahlavi. A key motive was to protect British oil interests in Iran after its government refused to concede to western oil demands. It was instigated by the United States (under the name TP-AJAX Project or Operation Ajax) and the United Kingdom (under the name Operation Boot). This began a period of dissolution for Iranian democracy and society.

Mosaddegh had sought to audit the documents of the Anglo-Iranian Oil Company (AIOC), a British corporation (now part of BP), to verify that AIOC was paying the contracted royalties to Iran, and to limit the company's control over Iranian oil reserves. Upon the AIOC's refusal to cooperate with the Iranian government, the parliament (Majlis) voted to nationalize Iran's oil industry and to expel foreign corporate representatives from the country. After this vote, Britain instigated a worldwide boycott of Iranian oil to pressure Iran economically. Initially, Britain mobilized its military to seize control of the British-built Abadan oil refinery, then the world's largest, but Prime Minister Clement Attlee (in power until 1951) opted instead to tighten the economic boycott while using Iranian agents to undermine Mosaddegh's government.^: 3 Judging Mosaddegh to be unamenable and fearing the growing influence of the communist Tudeh, UK prime minister Winston Churchill and the Eisenhower administration decided in early 1953 to overthrow Iran's government. The preceding Truman administration had opposed a coup, fearing the precedent that Central Intelligence Agency (CIA) involvement would set,^: 3 and the U.S. government had been considering unilateral action (without UK support) to assist the Mosaddegh government as late as 1952. British intelligence officials' conclusions and the UK government's solicitations to the US were instrumental in initiating and planning the coup.

Following the coup, a government under General Fazlollah Zahedi was formed which allowed Mohammad Reza Pahlavi, the shah of Iran (Persian for 'king'), to rule more firmly as monarch. He relied heavily on United States support to hold on to power. According to the CIA's declassified documents and records, some of the most feared mobsters in Tehran were hired by the CIA to stage pro-shah riots on 19 August. Other men paid by the CIA were brought into Tehran in buses and trucks and took over the streets of the city. Between 200 and 300 people were killed because of the conflict. Mosaddegh was arrested, tried and convicted of treason by the Shah's military court. On 21 December 1953, he was sentenced to three years in jail, then placed under house arrest for the remainder of his life.^: 280 Other Mosaddegh supporters were imprisoned, and several received the death penalty. The coup strengthened the Shah's authority, and he continued to rule Iran for the next 26 years as a pro-Western monarch until he was overthrown in the Iranian Revolution in 1979.

In August 2013, the U.S. government formally acknowledged the U.S. role in the coup by releasing a bulk of previously classified government documents that show it was in charge of both the planning and the execution of the coup. According to American journalist Stephen Kinzer, the operation included false flag attacks, paid protesters, provocations, the bribing of Iranian politicians and high-ranking security and army officials, as well as pro-coup propaganda. The CIA is quoted as acknowledging the coup was carried out "under CIA direction" and "as an act of U.S. foreign policy, conceived and approved at the highest levels of government". In 2023, the CIA took credit for the coup, contradicting a previous scholarly assessment that the CIA had botched the operation, though other assessments agreed that America and Britain had engineered the coup.

In 2011, Randall Munroe in his comic xkcd coined the term "citogenesis" to describe the creation of "reliable" sources through circular reporting. This is a list of some well-documented cases where Wikipedia has been the source.

🔗 Aviation 🔗 Canada 🔗 Aviation/aircraft 🔗 Amateur radio 🔗 Canada/Alberta

Balloon Experiments with Amateur Radio (BEAR) is a series of Canadian-based amateur radio high-altitude balloon experiments by a group of amateur radio operators and experimenters from Sherwood Park and Edmonton, Alberta. The experiments started in the year 2000 and continued with BEAR-9 in 2012 reaching 36,010 metres (118,140 ft).

The balloons are made of latex filled with either helium or hydrogen. All of the BEAR payloads carry a tracking system comprising a GPS receiver, an APRS encoder, and a radio transmitter module. Other experimental payload modules include an Amateur Radio crossband repeater, and a digital camera all of which is contained within an insulated foam box suspended below the balloon. A parachute recovery system is automatically deployed when the balloon bursts at altitude.

🔗 Biography 🔗 London 🔗 Biography/science and academia 🔗 Engineering

Thomas Harold Flowers MBE (22 December 1905 - 28 October 1998) was an English engineer with the British General Post Office. During World War II, Flowers designed and built Colossus, the world's first programmable electronic computer, to help decipher encrypted German messages.

🔗 Psychology 🔗 Cognitive science

Functional fixedness is a cognitive bias that limits a person to use an object only in the way it is traditionally used. The concept of functional fixedness originated in Gestalt psychology, a movement in psychology that emphasizes holistic processing. Karl Duncker defined functional fixedness as being a "mental block against using an object in a new way that is required to solve a problem". This "block" limits the ability of an individual to use components given to them to complete a task, as they cannot move past the original purpose of those components. For example, if someone needs a paperweight, but they only have a hammer, they may not see how the hammer can be used as a paperweight. Functional fixedness is this inability to see a hammer's use as anything other than for pounding nails; the person couldn't think to use the hammer in a way other than in its conventional function.

When tested, 5-year-old children show no signs of functional fixedness. It has been argued that this is because at age 5, any goal to be achieved with an object is equivalent to any other goal. However, by age 7, children have acquired the tendency to treat the originally intended purpose of an object as special.