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🔗 Philosophy 🔗 Philosophy/Logic 🔗 Philosophy/Philosophy of mind

The knowledge argument (also known as Mary's room or Mary the super-scientist) is a philosophical thought experiment proposed by Frank Jackson in his article "Epiphenomenal Qualia" (1982) and extended in "What Mary Didn't Know" (1986). The experiment is intended to argue against physicalism—the view that the universe, including all that is mental, is entirely physical. The debate that emerged following its publication became the subject of an edited volume—There's Something About Mary (2004)—which includes replies from such philosophers as Daniel Dennett, David Lewis, and Paul Churchland.

🔗 Maps

In cartography, a trap street is a fictitious entry in the form of a misrepresented street on a map, often outside the area the map nominally covers, for the purpose of "trapping" potential copyright violators of the map who, if caught, would be unable to explain the inclusion of the "trap street" on their map as innocent. On maps that are not of streets, other "copyright trap" features (such as nonexistent towns, or mountains with the wrong elevations) may be inserted or altered for the same purpose.

Trap streets are often nonexistent streets; but sometimes, rather than actually depicting a street where none exists, a map will misrepresent the nature of a street in a fashion that can still be used to detect copyright violators but is less likely to interfere with navigation. For instance, a map might add nonexistent bends to a street, or depict a major street as a narrow lane, without changing its location or its connections to other streets.

Trap streets are rarely acknowledged by publishers. One known case is a popular driver's atlas for the city of Athens, Greece, which has a warning inside its front cover that potential copyright violators should beware of trap streets.

🔗 Chemistry 🔗 Animals 🔗 Molecular Biology/Molecular and Cell Biology

Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bioluminescent bacteria, and terrestrial arthropods such as fireflies. In some animals, the light is bacteriogenic, produced by symbiotic bacteria such as those from the genus Vibrio; in others, it is autogenic, produced by the animals themselves.

In a general sense, the principal chemical reaction in bioluminescence involves a light-emitting molecule and an enzyme, generally called luciferin and luciferase, respectively. Because these are generic names, luciferins and luciferases are often distinguished by the species or group, e.g. firefly luciferin. In all characterized cases, the enzyme catalyzes the oxidation of the luciferin.

In some species, the luciferase requires other cofactors, such as calcium or magnesium ions, and sometimes also the energy-carrying molecule adenosine triphosphate (ATP). In evolution, luciferins vary little: one in particular, coelenterazine, is found in 11 different animal phyla, though in some of these, the animals obtain it through their diet. Conversely, luciferases vary widely between different species, which is evidence that bioluminescence has arisen over 40 times in evolutionary history.

Both Aristotle and Pliny the Elder mentioned that damp wood sometimes gives off a glow. Many centuries later Robert Boyle showed that oxygen was involved in the process, in both wood and glowworms. It was not until the late nineteenth century that bioluminescence was properly investigated. The phenomenon is widely distributed among animal groups, especially in marine environments. On land it occurs in fungi, bacteria and some groups of invertebrates, including insects.

The uses of bioluminescence by animals include counterillumination camouflage, mimicry of other animals, for example to lure prey, and signaling to other individuals of the same species, such as to attract mates. In the laboratory, luciferase-based systems are used in genetic engineering and biomedical research. Researchers are also investigating the possibility of using bioluminescent systems for street and decorative lighting, and a bioluminescent plant has been created.

🔗 Japan 🔗 Japan/Culture

Cool Japan (クールジャパン, Kūru Japan) refers to the aspects of Japanese culture that non-Japanese people perceive as "cool". The Cool Japan strategy is part of Japan's overall brand strategy, aiming to disseminate Japan's attractiveness and allure to the world. The target of Cool Japan "encompasses everything from games, manga, anime, and other forms of content, fashion, commercial products, Japanese cuisine, and traditional culture to robots, eco-friendly technologies, and other high-tech industrial products".

Cool Japan has been described as a form of soft power, with the ability to "indirectly influence behavior or interests through cultural or ideological means".

🔗 Philately 🔗 Japan 🔗 Japan/Infrastructure 🔗 Japan/Law and government

The Japanese addressing system is used to identify a specific location in Japan. When written in Japanese characters, addresses start with the largest geographical entity and proceed to the most specific one. When written in Latin characters, addresses follow the convention used by most Western addresses and start with the smallest geographic entity (typically a house number) and proceed to the largest. The Japanese system is complex and idiosyncratic, the product of the natural growth of urban areas, as opposed to the systems used in cities that are laid out as grids and divided into quadrants or districts.

🔗 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.

🔗 Companies 🔗 France 🔗 Automobiles 🔗 Japan 🔗 Japan/Business and economy 🔗 Japan/Car

The Renault–Nissan–Mitsubishi Alliance, originally known as the Renault–Nissan Alliance, is a French-Japanese strategic alliance between the automobile manufacturers Renault (based in Boulogne-Billancourt, France), Nissan (based in Yokohama, Japan) and Mitsubishi Motors (based in Tokyo, Japan), which together sell more than 1 in 9 vehicles worldwide. Renault and Nissan are strategic partners since 1999 and have nearly 450,000 employees and control eight major brands: Renault, Nissan, Mitsubishi, Infiniti, Renault Korea, Dacia, Alpine, and Venucia. The car group sold 10.6 million vehicles worldwide in 2017, making it the leading light vehicle manufacturing group in the world. The Alliance adopted its current name in September 2017, one year after Nissan acquired a controlling interest in Mitsubishi and subsequently made Mitsubishi an equal partner in the Alliance.

As of December 2021, the Alliance is one of the world's leading electric vehicle manufacturing groups, with global sales of over 1 million light-duty electric vehicles since 2009. The top selling vehicles of its EV line-up are the Nissan Leaf and the Renault Zoe all-electric cars.

The strategic partnership between Renault, Nissan and Mitsubishi is not a merger or an acquisition. The three companies are joined through a cross-sharing agreement. The structure was unique in the auto industry during the 1990s consolidation trend and later served as a model for General Motors and the PSA Group, and Mitsubishi, as well as the Volkswagen Group and Suzuki, though the latter combination failed. The Alliance itself has broadened its scope substantially, forming additional partnerships with automakers including Germany's Daimler and China's Dongfeng.

Following the November 2018 arrest and imprisonment of Alliance chairman and CEO Carlos Ghosn, accompanied by his dismissal from the alliance and its components, press analysts have questioned both the stability of the Alliance's shareholding agreement and its long-term existence. These analysts also note that, because the companies' recent business strategies are interdependent, attempts to restructure the Alliance could be counter-productive for all of the members.

In January 2023, Renault and Nissan moved to restructure their alliance in order to recover from Ghosn's arrest and manage through a post-Covid economy. The primary objective was to give both companies more autonomy.

🔗 Spaceflight 🔗 Physics 🔗 Systems 🔗 Systems/Dynamical systems

The Interplanetary Transport Network (ITN) is a collection of gravitationally determined pathways through the Solar System that require very little energy for an object to follow. The ITN makes particular use of Lagrange points as locations where trajectories through space are redirected using little or no energy. These points have the peculiar property of allowing objects to orbit around them, despite lacking an object to orbit. While it would use little energy, transport along the network would take a long time.

🔗 Computing 🔗 Computer science

In computer science, the five-minute rule is a rule of thumb for deciding whether a data item should be kept in memory, or stored on disk and read back into memory when required. It was first formulated by Jim Gray and Gianfranco Putzolu in 1985, and then subsequently revised in 1997 and 2007 to reflect changes in the relative cost and performance of memory and persistent storage.

The rule is as follows:

The 5-minute random rule: cache randomly accessed disk pages that are re-used every 5 minutes or less.

Gray also issued a counterpart one-minute rule for sequential access:

The 1-minute rule: cache sequentially accessed disk pages that are re-used every 1 minute or less.

Although the 5-minute rule was invented in the realm of databases, it has also been applied elsewhere, for example, in Network File System cache capacity planning.

The original 5-minute rule was derived from the following cost-benefit computation:

BreakEvenIntervalinSeconds = (PagesPerMBofRAM / AccessesPerSecondPerDisk) × (PricePerDiskDrive / PricePerMBofRAM)

Applying it to 2007 data yields approximately a 90-minutes interval for magnetic-disk-to-DRAM caching, 15 minutes for SSD-to-DRAM caching and 2​¹⁄₄ hours for disk-to-SSD caching. The disk-to-DRAM interval was thus a bit short of what Gray and Putzolu anticipated in 1987 as the "five-hour rule" was going to be in 2007 for RAM and disks.

According to calculations by NetApp engineer David Dale as reported in The Register, the figures for disc-to-DRAM caching in 2008 were as follows: "The 50KB page break-even was five minutes, the 4KB one was one hour and the 1KB one was five hours. There needed to be a 50-fold increase in page size to cache for break-even at five minutes." Regarding disk-to-SSD caching in 2010, the same source reported that "A 250KB page break even with SLC was five minutes, but five hours with a 4KB page size. It was five minutes with a 625KB page size with MLC flash and 13 hours with a 4KB MLC page size."

In 2000, Gray and Shenoy applied a similar calculation for web page caching and concluded that a browser should "cache web pages if there is any chance they will be re-referenced within their lifetime."

🔗 Animal anatomy 🔗 Marine life 🔗 Limnology and Oceanography

Spicules are structural elements found in most sponges. The meshing of many spicules serves as the sponge's skeleton and thus it provides structural support and potentially defense against predators.

Sponge spicules are made of calcium carbonate or silica. Large spicules visible to the naked eye are referred to as megascleres, while smaller, microscopic ones are termed microscleres. The composition, size, and shape of spicules are major characters in sponge systematics and taxonomy.