Random Articles (Page 2)
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🔗 List of sensors
This is a list of sensors sorted by sensor type.
Discussed on
- "List of sensors" | 2022-07-04 | 17 Upvotes 1 Comments
🔗 Naismith's Rule
Naismith's rule helps with the planning of a walking or hiking expedition by calculating how long it will take to travel the intended route, including any extra time taken when walking uphill. This rule of thumb was devised by William W. Naismith, a Scottish mountaineer, in 1892. A modern version can be formulated as follows:
- Allow one hour for every 3 miles (5 km) forward, plus an additional hour for every 2,000 feet (600 m) of ascent.
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- "Naismith's Rule" | 2024-04-11 | 47 Upvotes 14 Comments
🔗 Product Red
Product Red, stylized as (PRODUCT)RED or (PRODUCT)RED, is a licensed brand by the company Red, stylized as (RED), that seeks to engage the private sector in raising awareness and funds to help eliminate HIV/AIDS in eight African countries, namely Eswatini (formerly Swaziland), Ghana, Kenya, Lesotho, Rwanda, South Africa, Tanzania, and Zambia. It is licensed to partner companies including Apple Inc., Nike, American Express (UK), The Coca-Cola Company, Starbucks, Converse, Electronic Arts, Primark, Head, Buckaroo, Penguin Classics (UK & International), Gap, Armani, FIAT, Hallmark (US), SAP, Beats Electronics, and Supercell. The concept was founded in 2006 by U2 frontman and activist Bono, together with Bobby Shriver of the One Campaign and DATA. The Global Fund to Fight AIDS, Tuberculosis and Malaria is the recipient of Product Red's money.
As part of a new business model, each partner company creates a product with the Product Red logo. In return for the opportunity to increase revenue through the Product Red license, up to 50% of profits gained by each partner is donated to the Global Fund. As Product Red is owned by Red, a portion of the contributions received from the partner brands is assigned as profit. Such an amalgamation of humanitarian aid and for-profit businesses is one example of "ethical consumerism".
In 2012, One Campaign acquired Red as a division of One. Both organizations were co-founded by Bono and Shriver.
Since 2020, Product Red has been used in the global fund to combat the COVID-19 pandemic.
Discussed on
- "Product Red" | 2022-12-01 | 38 Upvotes 49 Comments
🔗 Herd Immunity
Herd immunity (also called herd effect, community immunity, population immunity, or social immunity) is a form of indirect protection from infectious disease that occurs when a large percentage of a population has become immune to an infection, whether through previous infections or vaccination, thereby providing a measure of protection for individuals who are not immune. In a population in which a large proportion of individuals possess immunity, such people being unlikely to contribute to disease transmission, chains of infection are more likely to be disrupted, which either stops or slows the spread of disease. The greater the proportion of immune individuals in a community, the smaller the probability that non-immune individuals will come into contact with an infectious individual, helping to shield non-immune individuals from infection.
Individuals can become immune by recovering from an earlier infection or through vaccination. Some individuals cannot become immune due to medical reasons, such as an immunodeficiency or immunosuppression, and in this group herd immunity is a crucial method of protection. Once a certain threshold has been reached, herd immunity gradually eliminates a disease from a population. This elimination, if achieved worldwide, may result in the permanent reduction in the number of infections to zero, called eradication. Herd immunity created via vaccination contributed to the eventual eradication of smallpox in 1977 and has contributed to the reduction of the frequencies of other diseases. Herd immunity does not apply to all diseases, just those that are contagious, meaning that they can be transmitted from one individual to another. Tetanus, for example, is infectious but not contagious, so herd immunity does not apply.
The term "herd immunity" was first used in 1923. It was recognized as a naturally occurring phenomenon in the 1930s when it was observed that after a significant number of children had become immune to measles, the number of new infections temporarily decreased, including among susceptible children. Mass vaccination to induce herd immunity has since become common and proved successful in preventing the spread of many infectious diseases. Opposition to vaccination has posed a challenge to herd immunity, allowing preventable diseases to persist in or return to communities that have inadequate vaccination rates.
Discussed on
- "Herd Immunity" | 2020-03-14 | 46 Upvotes 72 Comments
🔗 Toxoplasma Gondii
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.
🔗 Langton's Ant
Langton's ant is a two-dimensional universal Turing machine with a very simple set of rules but complex emergent behavior. It was invented by Chris Langton in 1986 and runs on a square lattice of black and white cells. The universality of Langton's ant was proven in 2000. The idea has been generalized in several different ways, such as turmites which add more colors and more states.
Discussed on
- "Langton’s ant" | 2023-05-17 | 102 Upvotes 23 Comments
- "Langton's Ant" | 2019-06-07 | 115 Upvotes 25 Comments
- "Langton's ant" | 2014-09-03 | 118 Upvotes 42 Comments
- "Langton's ant" | 2011-02-17 | 176 Upvotes 20 Comments
🔗 ACT-R: A cognitive architecture
ACT-R (pronounced /ˌækt ˈɑr/; short for "Adaptive Control of Thought—Rational") is a cognitive architecture mainly developed by John Robert Anderson and Christian Lebiere at Carnegie Mellon University. Like any cognitive architecture, ACT-R aims to define the basic and irreducible cognitive and perceptual operations that enable the human mind. In theory, each task that humans can perform should consist of a series of these discrete operations.
Most of the ACT-R's basic assumptions are also inspired by the progress of cognitive neuroscience, and ACT-R can be seen and described as a way of specifying how the brain itself is organized in a way that enables individual processing modules to produce cognition.
Discussed on
- "ACT-R: A cognitive architecture" | 2015-12-17 | 20 Upvotes 4 Comments
🔗 Citicorp Center Engineering Crisis
The Citicorp Center engineering crisis was the discovery, in 1978, of a significant structural flaw in Citicorp Center, then a recently completed skyscraper in New York City, and the subsequent effort to quietly make repairs over the next few months. The building, now known as Citigroup Center, occupied an entire block and was to be the headquarters of Citibank. Its structure, designed by William LeMessurier, had several unusual design features, including a raised base supported by four offset stilts, and diagonal bracing which absorbed wind loads from upper stories.
In the original design, potential wind loads for the building were calculated incorrectly. The flaw was discovered by Diane Hartley, an undergraduate student at Princeton University who was writing a thesis on the building, and was communicated to the firm responsible for the structural design. LeMessurier was subsequently lauded for acknowledging his error and orchestrating a successful repair effort. Estimates at the time suggested that the building could be toppled by a 70-mile-per-hour (110 km/h) wind, with possibly many people killed as a result. The crisis was kept secret until 1995 and Hartley had no knowledge of the significance of her work until after that time.
Discussed on
- "Citicorp Center Engineering Crisis" | 2022-05-21 | 18 Upvotes 1 Comments
🔗 Druze
The Druze (; Arabic: دَرْزِيٌّ, darzī or Arabic: دُرْزِيٌّ durzī, pl. دُرُوزٌ, durūz), known to adherents as al-Muwaḥḥidūn (Monotheists) or Muwaḥḥidūn (unitarians), are an Arab and Arabic-speaking esoteric ethnoreligious group from Western Asia who adhere to the Druze faith, an Abrahamic, monotheistic, syncretic, and ethnic religion whose main tenets are the unity of God and the belief in reincarnation and the eternity of the soul. Adherents of the Druze religion call themselves simply "the Monotheists" (al-Muwaḥḥidūn). Most Druze religious practices are kept secret. The Druze do not permit outsiders to convert to their religion. Marriage outside the Druze faith is rare and strongly discouraged.
The Epistles of Wisdom is the foundational and central text of the Druze faith. The Druze faith incorporates elements of Isma'ilism, Christianity, Gnosticism, Neoplatonism, Zoroastrianism, Buddhism, Hinduism, Pythagoreanism, and other philosophies and beliefs, creating a distinct and secretive theology based on an esoteric interpretation of scripture, which emphasizes the role of the mind and truthfulness. Druze believe in theophany and reincarnation. Druze believe that at the end of the cycle of rebirth, which is achieved through successive reincarnations, the soul is united with the Cosmic Mind (al-ʻaql al-kullī).
The Druze have a special reverence for Shuaib, who they believe is the same person as the biblical Jethro. The Druze believe that Adam, Noah, Abraham, Moses, Jesus, Muhammad, and Isma'il ibn Ja'far were prophets. Druze tradition also honors and reveres Salman the Persian, al-Khidr (who they identify as Elijah, reborn as John the Baptist and Saint George), Job, Luke the Evangelist, and others as "mentors" and "prophets".
Even though the faith originally developed out of Isma'ilism, the Druze are not Muslims. The Druze faith is one of the major religious groups in the Levant, with between 800,000 and a million adherents. They are found primarily in Lebanon, Syria, and Israel, with small communities in Jordan. They make up 5.5% of the population of Lebanon, 3% of Syria and 1.6% of Israel. The oldest and most densely-populated Druze communities exist in Mount Lebanon and in the south of Syria around Jabal al-Druze (literally the "Mountain of the Druze").
The Druze community played a critically important role in shaping the history of the Levant, where it continues to play a significant political role. As a religious minority in every country in which they are found, they have frequently experienced persecution by different Muslim regimes, including contemporary Islamic extremism.
Discussed on
- "Druze" | 2023-09-04 | 22 Upvotes 2 Comments
🔗 Chants of Sennaar
Chants of Sennaar is a 2023 adventure video game developed by Rundisc and published by Focus Entertainment. Players solve puzzles and minigames to translate fictional languages.
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- "Chants of Sennaar" | 2023-12-26 | 10 Upvotes 1 Comments