Summary

HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

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Direct Methods (Electron Microscopy)
In crystallography, direct methods is a set of techniques used for structure determination using diffraction data and a priori information. It is a solution to the crystallographic phase problem, where phase information is lost during a diffraction measurement. Direct methods provides a method of estimating the phase information by establishing statistical relationships between the recorded amplitude information and phases of strong reflections.
  • 813
  • 04 Nov 2022
Topic Review
Incompatible Timesharing System
Incompatible Timesharing System (ITS) is a time-sharing operating system developed principally by the MIT Artificial Intelligence Laboratory, with help from Project MAC. The name is the jocular complement of the MIT Compatible Time-Sharing System (CTSS). ITS, and the software developed on it, were technically and culturally influential far beyond their core user community. Remote "guest" or "tourist" access was easily available via the early ARPAnet, allowing many interested parties to informally try out features of the operating system and application programs. The wide-open ITS philosophy and collaborative online community were a major influence on the hacker culture, as described in Steven Levy's book Hackers, and were the direct forerunners of the free and open-source software, open-design, and Wiki movements.
  • 825
  • 04 Nov 2022
Topic Review
Postinternet
Postinternet denotes an idea in arts and criticism that refers to society and modes of interaction following the widespread adoption of the internet. The term emerged from discussions about Internet Art by Marisa Olson, Gene McHugh, and Artie Vierkant. Guthrie Lonergan and Cory Arcangel have mentioned it as a term for being "internet aware", which some believe to be more accurate. Generally it is described as art that is about the internet's effects on aesthetics, culture and society. Critics of the term claim that it falsely implies that there is a kind of art made after the internet has ceased to exist (and artists such as Rafael Rozendaal have criticized the ambiguity of "post-" in this instance).
  • 1.8K
  • 04 Nov 2022
Topic Review
130–30 Fund
A 130–30 fund or a ratio up to 150/50 is a type of collective investment vehicle, often a type of specialty mutual fund, but which allows the fund manager simultaneously to hold both long and short positions on different equities in the fund. Traditionally, mutual funds were long-only investments. 130–30 funds are a fast-growing segment of the financial industry; they should be available both as traditional mutual funds, and as exchange-traded funds (ETFs). While this type of investment has existed for a while in the hedge fund industry, its availability for retail investors is relatively new. A 130–30 fund is considered a long-short equity fund, meaning it goes both long and short at the same time. The "130" portion stands for 130% exposure to its long portfolio and the "30" portion stands for 30% exposure to its short portfolio. The structure usually ranges from 120–20 up to 150–50 with 130–30 being the most popular and is limited to 150/50 because of Reg T limiting the short side to 50%.
  • 847
  • 04 Nov 2022
Topic Review
Popliteal Bypass Surgery
Popliteal bypass surgery, more specifically known as femoral popliteal bypass surgery (FPB) or more generally as lower extremity bypass surgery, is a surgical procedure used to treat diseased leg arteries above or below the knee. It is used as a medical intervention to salvage limbs that are at risk of amputation and to improve walking ability in people with severe intermittent claudication (leg muscle pain) and ischemic rest pain. Popliteal bypass surgery is a common type of peripheral bypass surgery which carries blood from the femoral artery of the thigh to the end of the popliteal artery behind the knee. The femoral artery runs along the thigh and extends to become the popliteal artery which runs posteriorly to the knee joint and femur. Smaller arteries carry blood supply from the popliteal artery to the calf and into the foot. Blockages caused by plaque build-up or atherosclerosis in any of these arteries can reduce leg blood circulation, causing leg pain that may interfere with daily life. Standard Popliteal bypass surgery involves the bypass of the popliteal artery. During surgery, incisions are made depending on the location of the blockage. Usually, a healthy vein is located and sewn above and below the blockage to bypass the narrowed or blocked femoral artery. This allows the blood to be redirected to flow through the new healthy vessel around the blockage. In some cases, synthetic graft materials (such as polytetrafluoroethylene) are used instead of a vein graft.
  • 1.7K
  • 04 Nov 2022
Topic Review
Estonian Folklore Archives
The Estonian Folklore Archives (EFA) is the central folklore archives in Estonia. The Archives functions currently as the subdivision of the Estonian Literary Museum but it was established in 1927 as the division of the Estonian National Museum. The current Head of the Archives is Dr. Risto Järv (et).
  • 2.2K
  • 08 Nov 2022
Topic Review
Villa Tunari Massacre
The Villa Tunari Massacre was a 27 June 1988 mass murder committed by UMOPAR (Rural Patrol Mobile Unit) troops in response to a protest by coca-growing peasants (cocaleros) in the town of Villa Tunari in Chapare Province, Bolivia. The cocalero movement had mobilized since late May 1988 in opposition to coca eradication under Law 1008, then on the verge of becoming law. According to video evidence and a joint church-labor investigative commission, UMOPAR opened fired on unarmed protesters, at least two of whom were fatally shot, and many of whom fled to their deaths over a steep drop into the San Mateo River. The police violence caused the deaths of 9 to 12 civilian protesters, including three whose bodies were never found, and injured over a hundred. The killings were followed by further state violence in Villa Tunari, Sinahota, Ivirgarzama, and elsewhere in the region, including machine gun fire, beatings, and arrests. The massacre helped bring about the consolidation of Chapare coca growers' unions into the Coordinadora of the Six Federations of the Tropic of Cochabamba. Representatives of the National Congress, Catholic Church, Permanent Assembly for Human Rights, and the Central Obrera Boliviana labor federation formed a joint "multisectoral commission" to investigate the repression in the Chapare, which traveled to the region on 30 June 1988.
  • 1.2K
  • 04 Nov 2022
Topic Review
Criticism of Non-Standard Analysis
Non-standard analysis and its offshoot, non-standard calculus, have been criticized by several authors, notably Errett Bishop, Paul Halmos, and Alain Connes. These criticisms are analyzed below.
  • 956
  • 04 Nov 2022
Topic Review
Law of the Land
The phrase law of the land is a legal term, equivalent to the Latin lex terrae, or legem terrae in the accusative case. It refers to all of the laws in force within a country or region, including statute law and case-made law.
  • 2.9K
  • 04 Nov 2022
Topic Review
Baddeley's Model of Working Memory
Baddeley's model of working memory is a model of human memory proposed by Alan Baddeley and Graham Hitch in 1974, in an attempt to present a more accurate model of primary memory (often referred to as short-term memory). Working memory splits primary memory into multiple components, rather than considering it to be a single, unified construct. Baddeley & Hitch proposed their three-part working memory model as an alternative to the short-term store in Atkinson & Shiffrin's 'multi-store' memory model (1968). This model is later expanded upon by Baddeley and other co-workers to add a fourth component, and has become the dominant view in the field of working memory. However, alternative models are developing, providing a different perspective on the working memory system. The original model of Baddeley & Hitch was composed of three main components: the central executive which acts as a supervisory system and controls the flow of information from and to its slave systems: the phonological loop and the visuo-spatial sketchpad. The phonological loop stores verbal content, whereas the visuo-spatial sketchpad caters to visuo-spatial data. Both the slave systems only function as short-term storage centers. In 2000, Baddeley added a third slave system to his model, the episodic buffer. Baddeley & Hitch's argument for the distinction of two domain-specific slave systems in the older model was derived from experimental findings with dual-task paradigms. Performance of two simultaneous tasks requiring the use of two separate perceptual domains (i.e. a visual and a verbal task) is nearly as efficient as performance of the tasks individually. In contrast, when a person tries to carry out two tasks simultaneously that use the same perceptual domain, performance is less efficient than when performing the tasks individually. A fourth component of Baddeley's model was added 25 years later to complement the central executive system. The third slave system was designated as episodic buffer. It is considered a limited-capacity system that provides temporary storage of information by conjoining information from the subsidiary systems, and long-term memory, into a single episodic representation.
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  • 04 Nov 2022
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