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🔗 United States 🔗 United States/North Carolina 🔗 Appalachia 🔗 Tennessee

In the Appalachian Mountains of the eastern United States, balds are mountain summits or crests covered primarily by thick vegetation of native grasses or shrubs occurring in areas where heavy forest growth would be expected.

Balds are found primarily in the Southern Appalachians, where, even at the highest elevations, the climate is too warm to support an alpine zone, areas where trees fail to grow due to short or non-existent growing seasons. The difference between an alpine summit, such as Mount Washington in New Hampshire, and a bald, such as Gregory Bald in the Great Smoky Mountains, is that a lack of trees is normal for the colder climate of the former but abnormal for the warmer climate of the latter. One example of southern balds' abnormality can be found at Roan Mountain, where Roan High Knob (el. 6,285 ft/1,915 m) is coated with a dense stand of spruce-fir forest, whereas an adjacent summit, Round Bald (el. 5,826 ft/1,776 m), is almost entirely devoid of trees. Why some summits are bald and some are not is a mystery, though there are several hypotheses.

A stick bomb is a (mechanical) spring-loaded device constructed out of flat sticks woven together under a bending moment. Other names for stick bombs include Chinese stick puzzles, Cobra wave, and frame bombs. Stick bombs are created for fun and as art, not for any practical use.

PechaKucha (Japanese: ぺちゃくちゃ, IPA: [petɕa kɯ̥tɕa], chit-chat) is a storytelling format where a presenter shows 20 slides for 20 seconds of commentary each (6 minutes and 40 seconds total). At a PechaKucha Night, individuals gather at a venue to share personal presentations about their work. The PechaKucha format can be used, for example, in business presentations to clients or staff, as well as in education settings.

Inspired by their desire to "talk less, show more," Astrid Klein and Mark Dytham of Tokyo's Klein-Dytham Architecture (KDa) created PechaKucha in February 2003. It was a way to attract people to SuperDeluxe, their experimental event space in Roppongi, and to enable young designers to meet, show their work, and exchange ideas in 6 minutes 40 seconds.

In 2004, cities in Europe began hosting PK Nights and days, followed over the years by hundreds of others. As of April 2019, PKNs had been held in more than 1,142 cities worldwide. More than 3 million people have attended a PK Night.

PechaKucha is a registered trademark of PechaKucha, Inc.

In January 2018, PK's Astrid Klein, Mark Dytham, and Sean Smyth established PK, Inc. to create software to expand the PK platform.

🔗 United States 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 United States/Military history - U.S. military history 🔗 Military history/Intelligence 🔗 Military history/Maritime warfare 🔗 Ships 🔗 Israel 🔗 Palestine 🔗 Military history/Middle Eastern military history

The USS Liberty incident was an attack on a United States Navy technical research ship (spy ship), USS Liberty, by Israeli Air Force jet fighter aircraft and Israeli Navy motor torpedo boats, on 8 June 1967, during the Six-Day War. The combined air and sea attack killed 34 crew members (naval officers, seamen, two marines, and one civilian NSA employee), wounded 171 crew members, and severely damaged the ship. At the time, the ship was in international waters north of the Sinai Peninsula, about 25.5 nautical miles (47.2 km; 29.3 mi) northwest from the Egyptian city of Arish.

Israel apologized for the attack, saying that the USS Liberty had been attacked in error after being mistaken for an Egyptian ship. Both the Israeli and U.S. governments conducted inquiries and issued reports that concluded the attack was a mistake due to Israeli confusion about the ship's identity. Others, including survivors of the attack, have rejected these conclusions and maintain that the attack was deliberate.

In May 1968, the Israeli government paid US$3.32 million (equivalent to US$29.1 million in 2023) to the U.S. government in compensation for the families of the 34 men killed in the attack. In March 1969, Israel paid a further $3.57 million ($29.6 million in 2023) to the men who had been wounded. In December 1980, it agreed to pay $6 million ($22.2 million in 2023) as the final settlement for material damage to the ship plus 13 years of interest.

🔗 Economics 🔗 Business

The principal–agent problem, in political science, supply chain management and economics (also known as agency dilemma or the agency problem) occurs when one person or entity (the "agent"), is able to make decisions and/or take actions on behalf of, or that impact, another person or entity: the "principal". This dilemma exists in circumstances where agents are motivated to act in their own best interests, which are contrary to those of their principals, and is an example of moral hazard. Issues also arise when companies have an incentive to become increasingly deferential to management that have ownership stakes. As shareholders are dis-incentived to intervene, there are fewer checks on management. Issues can also arise among different types of management.

Common examples of this relationship include corporate management (agent) and shareholders (principal), elected officials (agent) and citizens (principal), or brokers (agent) and markets (buyers and sellers, principals). Consider a legal client (the principal) wondering whether their lawyer (the agent) is recommending protracted legal proceedings because it is truly necessary for the client's well-being, or because it will generate income for the lawyer. In fact the problem can arise in almost any context where one party is being paid by another to do something where the agent has a small or nonexistent share in the outcome, whether in formal employment or a negotiated deal such as paying for household jobs or car repairs.

The principal–agent problem typically arises where the two parties have different interests and asymmetric information (the agent having more information), such that the principal cannot directly ensure that the agent is always acting in their (the principal's) best interest, particularly when activities that are useful to the principal are costly to the agent, and where elements of what the agent does are costly for the principal to observe (see moral hazard and conflict of interest). Often, the principal may be sufficiently concerned at the possibility of being exploited by the agent that they choose not to enter into the transaction at all, when it would have been mutually beneficial: a suboptimal outcome that can lower welfare overall. The deviation from the principal's interest by the agent is called "agency costs".

The agency problem can be intensified when an agent acts on behalf of multiple principals (see multiple principal problem). When one agent acts on behalf of multiple principals, the multiple principals have to agree on the agent's objectives, but face a collective action problem in governance, as individual principals may lobby the agent or otherwise act in their individual interests rather than in the collective interest of all principals. As a result, there may be free-riding in steering and monitoring, duplicate steering and monitoring, or conflict between principals, all leading to high autonomy for the agent. The multiple principal problem is particularly serious in the public sector, where multiple principals are common and both efficiency and democratic accountability are undermined in the absence of salient governance. This problem may occur, for example, in the governance of the executive power, ministries, agencies, intermunicipal cooperation, public-private partnerships, and firms with multiple shareholders.

The relationships between investment managers and corporate management is an especially common example of the principal–agent relationship. There are several drivers of agency problems that affect investment managers of index funds and mutual funds include. First, investment managers receive a fraction of the benefits resulting from stewardship activities while having to handle all the costs. competition among investment managers is can also contribute to agency problems.And, lastly, another driver of agency problems is that investment managers can be heavily influenced by private incentives provided by the managers of corporations.

Various mechanisms may be used to align the interests of the agent with those of the principal. In employment, employers (principal) may use piece rates/commissions, profit sharing, efficiency wages, performance measurement (including financial statements), the agent posting a bond, or the threat of termination of employment to align worker interests with their own.

🔗 Mathematics

The 15-puzzle (also called Gem Puzzle, Boss Puzzle, Game of Fifteen, Mystic Square and many others) is a sliding puzzle that consists of a frame of numbered square tiles in random order with one tile missing. The puzzle also exists in other sizes, particularly the smaller 8-puzzle. If the size is 3×3 tiles, the puzzle is called the 8-puzzle or 9-puzzle, and if 4×4 tiles, the puzzle is called the 15-puzzle or 16-puzzle named, respectively, for the number of tiles and the number of spaces. The object of the puzzle is to place the tiles in order by making sliding moves that use the empty space.

The n-puzzle is a classical problem for modelling algorithms involving heuristics. Commonly used heuristics for this problem include counting the number of misplaced tiles and finding the sum of the taxicab distances between each block and its position in the goal configuration. Note that both are admissible, i.e. they never overestimate the number of moves left, which ensures optimality for certain search algorithms such as A*.

🔗 International relations 🔗 Human rights 🔗 Russia 🔗 Military history 🔗 Crime 🔗 Death 🔗 Ukraine 🔗 Russia/Russian, Soviet, and CIS military history 🔗 Military history/Russian, Soviet and CIS military history

In March 2022, a series of war crimes were committed by Russian occupation forces in the Ukrainian city of Bucha during the Battle of Bucha, following the Russian invasion of Ukraine. Ukrainian authorities said that more than 300 inhabitants of the town had been killed.

🔗 Spaceflight 🔗 Rocketry 🔗 Science 🔗 Photography

The V-2 No. 13 was a modified V-2 rocket that became the first object to take a photograph of the Earth from outer space. Launched on 24 October 1946, at the White Sands Missile Range in White Sands, New Mexico, the rocket reached a maximum altitude of 65 mi (105 km).

🔗 United States 🔗 Biography 🔗 Computer science 🔗 Women scientists 🔗 Biography/science and academia 🔗 Virginia

Gladys Brown West (née Gladys Mae Brown; October 27, 1930 – January 17, 2026) was an African American mathematician. She was known for her contributions to mathematical modeling of the shape of the Earth, and her work on the development of satellite geodesy models, which were later incorporated into the Global Positioning System (GPS).

West was inducted into the United States Air Force Hall of Fame in 2018. She was awarded the Webby Lifetime Achievement Award for the development of satellite geodesy models.

🔗 Video games

The Corrupted Blood incident was a virtual pandemic in the MMORPG World of Warcraft, which began on September 13, 2005, and lasted for one week. The epidemic began with the introduction of the new raid Zul'Gurub and its end boss Hakkar the Soulflayer. When confronted and attacked, Hakkar would cast a hit point-draining and highly contagious debuff spell called "Corrupted Blood" on players.

The spell, intended to last only seconds and function only within the new area of Zul'Gurub, soon spread across the virtual world by way of an oversight that allowed pets and minions to take the affliction out of its intended confines. By both accidental and purposeful intent, a pandemic ensued that quickly killed lower-level characters and drastically changed normal gameplay, as players did what they could do to avoid infection. Despite measures such as programmer-imposed quarantines, and the players' abandoning of densely populated cities (or even just not playing the game), it lasted until a combination of patches and resets of the virtual world finally controlled the spread.

The conditions and reactions of the event attracted the attention of epidemiologists for its implications of how human populations could react to a real-world epidemic.