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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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TAL Effector
TAL (transcription activator-like) effectors (often referred to as TALEs, but not to be confused with the three amino acid loop extension homeobox class of proteins) are proteins secreted by Xanthomonas bacteria via their type III secretion system when they infect various plant species. These proteins can bind promoter sequences in the host plant and activate the expression of plant genes that aid bacterial infection. They recognize plant DNA sequences through a central repeat domain consisting of a variable number of ~34 amino acid repeats. There appears to be a one-to-one correspondence between the identity of two critical amino acids in each repeat and each DNA base in the target sequence. These proteins are interesting to researchers both for their role in disease of important crop species and the relative ease of retargeting them to bind new DNA sequences. Similar proteins can be found in the pathogenic bacterium Ralstonia solanacearum and Burkholderia rhizoxinica., as well as yet unidentified marine microorganisms. The term TALE-likes is used to refer to the putative protein family encompassing the TALEs and these related proteins.
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  • 08 Nov 2022
Topic Review
Hangul (Obsolete Unicode Block)
Hangul, Hangul Supplementary-A, and Hangul Supplementary-B were character blocks that existed in Unicode 1.0 and 1.1, and ISO/IEC 10646-1:1993. These blocks encoded precomposed modern Hangul syllables. These three Unicode 1.x blocks were deleted and superseded by the new Hangul Syllables block (U+AC00–U+D7AF) in Unicode 2.0 (July 1996) and ISO/IEC 10646-1:1993 Amd. 5 (1998), and are now occupied by CJK Unified Ideographs Extension A and Yijing Hexagram Symbols. Moving or removing existing characters has been prohibited by the Unicode Stability Policy for all versions following Unicode 2.0, so the Hangul Syllables block introduced in Unicode 2.0 is immutable.
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  • 08 Nov 2022
Topic Review
Space Apps
Space Apps is annual NASA's global hackathon, first held in April 2012, and serves as innovation incubation and civic engagement program. NASA and its partners put out challenges relating to current work for which space enthusiasts around the world of all backgrounds can develop innovative solutions (which can be more than just apps!), particularly focusing on use of NASA data and promoting education. The project, formerly run by NASA's Office of the Chief Information Officer, is part of NASA's Earth Science Mission Directorate and is a part of the Open Government Initiative founded under President Barack Obama "creating an unprecedented level of openness in Government." It also fulfills the United States’ commitments to the Open Government Partnership.
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  • 08 Nov 2022
Topic Review
List of Wartime Cross-Dressers
Many people have engaged in cross-dressing during wartime under various circumstances and for various motives. This has been especially true of women, whether while serving as a soldier in otherwise all-male armies, while protecting themselves or disguising their identity in dangerous circumstances, or for other purposes. Conversely, men would dress as women to avoid being drafted, the mythological precedent for this being Achilles hiding at the court of Lycomedes dressed as a girl to avoid participation in the Trojan War.
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  • 08 Nov 2022
Topic Review
Utopia
A utopia (/juːˈtoʊpiə/ yoo-TOH-pee-ə) is an imaginary community or society that possesses highly desirable or nearly perfect qualities for its citizens. The term was coined by Sir Thomas More for his 1516 book Utopia, describing a fictional island society in the south Atlantic Ocean off the coast of South America. The opposite of a utopia is a dystopia, which dominates the fictional literature from the 1950s onwards, chiefly because of the impact of George Orwell's Nineteen Eighty-Four, published in 1949. However, the term can also denote actual experiments in what participants regard as a vastly superior manner of living, generally in what are termed intentional communities. In common parlance it is synonymous with "impossible", "far-fetched", and "deluded". Literary utopias focus on, amongst other things, equality, in such categories as economics, government and justice, with the method and structure of proposed implementation varying based on ideology. Lyman Tower Sargent argues that the nature of a utopia is inherently contradictory because societies are not homogeneous and have desires which conflict and therefore cannot simultaneously be satisfied. According to Sargent:
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  • 08 Nov 2022
Topic Review
Coomassie Brilliant Blue
Coomassie Brilliant Blue is the name of two similar triphenylmethane dyes that were developed for use in the textile industry but are now commonly used for staining proteins in analytical biochemistry. Coomassie Brilliant Blue G-250 differs from Coomassie Brilliant Blue R-250 by the addition of two methyl groups. The name "Coomassie" is a registered trademark of Imperial Chemical Industries.
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  • 08 Nov 2022
Topic Review
Secondary Treatment
Secondary treatment is a treatment process for wastewater (or sewage) to achieve a certain degree of effluent quality by using a sewage treatment plant with physical phase separation to remove settleable solids and a biological process to remove dissolved and suspended organic compounds. After this kind of treatment, the wastewater may be called as secondary-treated wastewater. Secondary treatment is the portion of a sewage treatment sequence removing dissolved and colloidal compounds measured as biochemical oxygen demand (BOD). Secondary treatment is traditionally applied to the liquid portion of sewage after primary treatment has removed settleable solids and floating material. Secondary treatment is typically performed by indigenous, aquatic microorganisms in a managed aerobic habitat. Bacteria and protozoa consume biodegradable soluble organic contaminants (e.g. sugars, fats, and organic short-chain carbon molecules from human waste, food waste, soaps and detergent) while reproducing to form cells of biological solids. Biological oxidation processes are sensitive to temperature and, between 0 °C and 40 °C, the rate of biological reactions increase with temperature. Most surface aerated vessels operate at between 4 °C and 32 °C.
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  • 08 Nov 2022
Topic Review
Social Integration
Social integration is the process during which newcomers or minorities are incorporated into the social structure of the host society. Social integration, together with economic integration and identity integration, are three main dimensions of a newcomers' experiences in the society that is receiving them. A higher extent of social integration contributes to a closer social distance between groups and more consistent values and practices. Bringing together various ethnic groups irrespective of language, caste, creed, etc., without losing one's identity. It gives access to all areas of community life and eliminates segregation. In a broader view, social integration is a dynamic and structured process in which all members participate in dialogue to achieve and maintain peaceful social relations. Social integration does not mean forced assimilation. Social integration is focused on the need to move toward a safe, stable and just society by mending conditions of social conflict, social disintegration, social exclusion, social fragmentation, exclusion and polarization, and by expanding and strengthening conditions of social integration towards peaceful social relations of coexistence, collaboration and cohesion.
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  • 08 Nov 2022
Topic Review
Transition of State
In quantum mechanics, particularly Perturbation theory, a transition of state is a change from an initial quantum state to a final one.
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Topic Review
Bush Encroachment
Bush encroachment (also shrub encroachment, woody encroachment, bush thickening, woody plant proliferation) is a natural phenomenon characterised by the increase in density of woody plants, bushes and shrubs, at the expense of the herbaceous layer, grasses and forbs. It predominantly occurs in grasslands, savannas and woodlands and can cause biome shifts from open grasslands and savannas to closed woodlands. The term bush encroachment refers to the expansion of native plants and not the spread of alien invasive species. It is thus defined by plant density, not species. Bush encroachment is often considered an ecological regime shift and can be a symptom of land degradation. Its causes include land use intensification, such as high grazing pressure and the suppression of wildfires. Climate change is found to be an accelerating factor for woody encroachment. The impact of bush encroachment is highly context specific. It is often found to have severe negative consequences on key ecosystem services, especially biodiversity, animal habitat, land productivity and groundwater recharge. Across rangelands, woody encroachment has led to significant declines of productivity, threatening the livelihoods of affected land users. The phenomenon is observed across different ecosystems and with different characteristics and intensities globally. Various countries actively counter woody encroachment, through adapted grassland management practices and targeted bush thinning. In some cases, areas affected by woody encroachment are classified as carbon sinks and form part of national greenhouse gas inventories. However, carbon sequestration effects of woody encroachment are highly context specific and still insufficiently researched.
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