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๐ List of mass shootings in the United States in 2022
This is a list of shootings in the United States that have occurred in 2022. Mass shootings are incidents involving several victims of firearm-related violence. The precise inclusion criteria are disputed, and there is no broadly accepted definition.
Gun Violence Archive, a nonprofit research group, run by Tracy Holtan, that tracks shootings and their characteristics in the United States, defines a mass shooting as an incident in which four or more people, excluding the perpetrator(s), are shot in one location at roughly the same time. The Congressional Research Service narrows that definition, limiting it to "public mass shootings", defined by four or more victims killed, excluding any victims who survive. The Washington Post and Mother Jones use similar definitions, with the latter acknowledging that their definition "is a conservative measure of the problem", as many shootings with fewer fatalities occur. The crowdsourced Mass Shooting Tracker project has the most expansive definition of four or more shot in any incident, including the perpetrator in the victim inclusion criteria.
A 2019 study of mass shootings published in the journal Injury Epidemiology recommended developing "a standard definition that considers both fatalities and nonfatalities to most appropriately convey the burden of mass shootings on gun violence." The authors of the study further suggested that "the definition of mass shooting should be four or more people, excluding the shooter, who are shot in a single event regardless of the motive, setting or number of deaths."
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- "List of mass shootings in the United States in 2022" | 2022-05-25 | 11 Upvotes 1 Comments
๐ Many-valued logic
In logic, a many-valued logic (also multi- or multiple-valued logic) is a propositional calculus in which there are more than two truth values. Traditionally, in Aristotle's logical calculus, there were only two possible values (i.e., "true" and "false") for any proposition. Classical two-valued logic may be extended to n-valued logic for n greater than 2. Those most popular in the literature are three-valued (e.g., ลukasiewicz's and Kleene's, which accept the values "true", "false", and "unknown"), the finite-valued (finitely-many valued) with more than three values, and the infinite-valued (infinitely-many-valued), such as fuzzy logic and probability logic.
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- "Many-valued logic" | 2019-06-14 | 106 Upvotes 81 Comments
๐ Zip gun
Improvised firearms (sometimes called zip guns or pipe guns) are firearms manufactured other than by a firearms manufacturer or a gunsmith, and are typically constructed by adapting existing materials to the purpose. They range in quality from crude weapons that are as much a danger to the user as the target to high-quality arms produced by cottage industries using salvaged and repurposed materials.
Improvised firearms are commonly used as tools by criminals and insurgents and are often associated with such groups; other uses include self-defense in lawless areas and hunting game in poor rural areas.
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- "Zip gun" | 2018-09-15 | 50 Upvotes 36 Comments
๐ B. Traven
B. Traven (German: [หbeห หtสaหvnฬฉ]; Bruno Traven in some accounts) was the pen name of a presumably German novelist, whose real name, nationality, date and place of birth and details of biography are all subject to dispute. One of the few certainties about Traven's life is that he lived for years in Mexico, where the majority of his fiction is also setโincluding The Treasure of the Sierra Madre (1927). The film adaptation of the same name won three Academy Awards in 1948.
Virtually every detail of Traven's life has been disputed and hotly debated. There were many hypotheses on the true identity of B. Traven, some of them wildly fantastic. The person most commonly identified as Traven is Ret Marut, a German stage actor and anarchist who supposedly left Europe for Mexico around 1924 and who had edited an anarchist newspaper in Germany called Der Ziegelbrenner (The Brick Burner). Marut is thought to have operated under the "B. Traven" pseudonym, although no details are known about Marut's life before 1912, and many hold that "Ret Marut" was in fact also a pseudonym.
Some researchers further argue that Marut/Traven's original name was Otto Feige and that he was born in Schwiebus in Brandenburg, modern-day ลwiebodzin in Poland. This theory is not universally accepted. B. Traven in Mexico is also connected with the names of Berick Traven Torsvan and Hal Croves, both of whom appeared and acted in different periods of the writer's life. Both, however, denied being Traven and claimed that they were his literary agents only, representing him in contacts with his publishers.
B. Traven is the author of twelve novels, one book of reportage and several short stories, in which the sensational and adventure subjects combine with a critical attitude towards capitalism. B. Traven's best known works include the novels The Death Ship from 1926, The Treasure of the Sierra Madre from 1927 (filmed in 1948 by John Huston), and the so-called "Jungle Novels", also known as the Caoba cyclus (from the Spanish word caoba, meaning mahogany). The Jungle Novels are a group of six novels (including The Carreta and Government), published in the years 1930โ1939 and set among Mexican Indians just before and during the Mexican Revolution in the early 20th century. B. Traven's novels and short stories became very popular as early as the interwar period and retained this popularity after the Second World War; they were also translated into many languages. Most of B. Traven's books were published in German first, with their English editions appearing later; nevertheless, the author always claimed that the English versions were the original ones and that the German versions were only their translations. This claim is mostly treated by Traven scholars as a diversion or a joke, although there are those who accept it.
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- "B. Traven" | 2021-04-17 | 107 Upvotes 36 Comments
๐ Universal Disk Format
Universal Disk Format (UDF) is a profile of the specification known as ISO/IEC 13346 and ECMA-167 and is an open vendor-neutral file system for computer data storage for a broad range of media. In practice, it has been most widely used for DVDs and newer optical disc formats, supplanting ISO 9660. Due to its design, it is very well suited to incremental updates on both recordable and (re)writable optical media. UDF is developed and maintained by the Optical Storage Technology Association (OSTA).
Normally, authoring software will master a UDF file system in a batch process and write it to optical media in a single pass. But when packet writing to rewritable media, such as CD-RW, UDF allows files to be created, deleted and changed on-disc just as a general-purpose filesystem would on removable media like floppy disks and flash drives. This is also possible on write-once media, such as CD-R, but in that case the space occupied by the deleted files cannot be reclaimed (and instead becomes inaccessible).
Multi-session mastering is also possible in UDF, though some implementations may be unable to read disks with multiple sessions.
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- "Universal Disk Format" | 2013-01-20 | 10 Upvotes 10 Comments
๐ Conservation-Induced Extinction
Conservation-induced extinction is where efforts to save endangered species lead to the extinction of other species. This mostly threatens the parasite and pathogen species that are highly host-specific to critically endangered hosts. When the last individuals of a host species are captured for the purpose of captive breeding and reintroduction programs, they typically undergo anti-parasitic treatments to increase survival and reproductive success. This practice may unintentionally result in the extinction of the species antagonistic to the target species, such as certain parasites. It has been proposed that the parasites should be reintroduced to the endangered population. A few cases of conservation-induced extinction have occurred in parasitic lice.
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- "Conservation-Induced Extinction" | 2024-07-26 | 13 Upvotes 2 Comments
๐ Flocken Elektrowagen
The Flocken Elektrowagen is a four-wheeled electric car designed by Andreas Flocken (1845โ1913), manufactured in 1888 by Maschinenfabrik A. Flocken in Coburg. It is regarded as the first real electric car.
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- "Flocken Elektrowagen" | 2025-01-18 | 17 Upvotes 3 Comments
๐ Mycorrhizal Network
A mycorrhizal network (also known as a common mycorrhizal network or CMN) is an underground network found in forests and other plant communities, created by the hyphae of mycorrhizal fungi joining with plant roots. This network connects individual plants together. Mycorrhizal relationships are most commonly mutualistic, with both partners benefiting, but can be commensal or parasitic, and a single partnership may change between any of the three types of symbiosis at different times. Mycorrhizal networks were discovered in 1997 by Suzanne Simard, professor of forest ecology at the University of British Columbia in Canada. Simard grew up in Canadian forests where her family had made a living as foresters for generations. Her field studies revealed that trees are linked to neighboring trees by an underground network of fungi that resembles the neural networks in the brain. In one study, Simard watched as a Douglas fir that had been injured by insects appeared to send chemical warning signals to a ponderosa pine growing nearby. The pine tree then produced defense enzymes to protect against the insect.
The formation and nature of these networks is context-dependent, and can be influenced by factors such as soil fertility, resource availability, host or mycosymbiont genotype, disturbance and seasonal variation. Some plant species, such as buckhorn plantain, a common lawn and agricultural weed, benefit from mycorrhizal relationships in conditions of low soil fertility, but are harmed in higher soil fertility. Both plants and fungi associate with multiple symbiotic partners at once, and both plants and fungi are capable of preferentially allocating resources to one partner over another.
Mycorrhizal associations have profoundly impacted the evolution of plant life on Earth ever since the initial adaptation of plant life to land. In evolutionary biology, mycorrhizal symbiosis has prompted inquiries into the possibility that symbiosis, not competition, is the main driver of evolution.
Referencing an analogous function served by the World Wide Web in human communities, the many roles that mycorrhizal networks appear to play in woodland have earned them a colloquial nickname: the "Wood Wide Web". Many of the claims made about common mycorrhizal networks, including that they are ubiquitous in forests, that resources are transferred between plants through them, and that they are used to transfer warnings between trees, have been criticised as being not strongly supported by evidence.
๐ The Pioneer Anomaly
The Pioneer anomaly or Pioneer effect was the observed deviation from predicted accelerations of the Pioneer 10 and Pioneer 11 spacecraft after they passed about 20 astronomical units (3ร109ย km; 2ร109ย mi) on their trajectories out of the Solar System. The apparent anomaly was a matter of much interest for many years but has been subsequently explained by an anisotropic radiation pressure caused by the spacecraft's heat loss.
Both Pioneer spacecraft are escaping the Solar System but are slowing under the influence of the Sun's gravity. Upon very close examination of navigational data, the spacecraft were found to be slowing slightly more than expected. The effect is an extremely small acceleration towards the Sun, of (8.74ยฑ1.33)ร10โ10ย m/s2, which is equivalent to a reduction of the outbound velocity by 1ย km/h over a period of ten years. The two spacecraft were launched in 1972 and 1973. The anomalous acceleration was first noticed as early as 1980 but not seriously investigated until 1994. The last communication with either spacecraft was in 2003, but analysis of recorded data continues.
Various explanations, both of spacecraft behavior and of gravitation itself, were proposed to explain the anomaly. Over the period from 1998 to 2012, one particular explanation became accepted. The spacecraft, which are surrounded by an ultra-high vacuum and are each powered by a radioisotope thermoelectric generator (RTG), can shed heat only via thermal radiation. If, due to the design of the spacecraft, more heat is emitted in a particular direction by what is known as a radiative anisotropy, then the spacecraft would accelerate slightly in the direction opposite of the excess emitted radiation due to the recoil of thermal photons. If the excess radiation and attendant radiation pressure were pointed in a general direction opposite the Sun, the spacecraft's velocity away from the Sun would be decreasing at a rate greater than could be explained by previously recognized forces, such as gravity and trace friction due to the interplanetary medium (imperfect vacuum).
By 2012 several papers by different groups, all reanalyzing the thermal radiation pressure forces inherent in the spacecraft, showed that a careful accounting of this explains the entire anomaly; thus the cause is mundane and does not point to any new phenomenon or need for a different physical paradigm. The most detailed analysis to date, by some of the original investigators, explicitly looks at two methods of estimating thermal forces, concluding that there is "no statistically significant difference between the two estimates and [...] that once the thermal recoil force is properly accounted for, no anomalous acceleration remains."
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- "The Pioneer Anomaly" | 2011-03-04 | 52 Upvotes 10 Comments
๐ ChandraโToueg consensus algorithm
The ChandraโToueg consensus algorithm, published by Tushar Deepak Chandra and Sam Toueg in 1996, is an algorithm for solving consensus in a network of unreliable processes equipped with an eventually strong failure detector. The failure detector is an abstract version of timeouts; it signals to each process when other processes may have crashed. An eventually strong failure detector is one that never identifies some specific non-faulty process as having failed after some initial period of confusion, and, at the same time, eventually identifies all faulty processes as failed (where a faulty process is a process which eventually fails or crashes and a non-faulty process never fails). The ChandraโToueg consensus algorithm assumes that the number of faulty processes, denoted by f, is less than n/2 (i.e. the minority), i.e. it assumes f < n/2, where n is the total number of processes.