TR
Theodore Roosevelt Jr. (October 27, 1858 – January 6, 1919), commonly known by his initials TR, was an American statesman, naturalist, conservationist, historian, explorer, soldier, and author who served as the 26th president of the United States from 1901 to 1909 following the assassination of William McKinley.[1][2][3][4] Roosevelt's presidency emphasized expanding federal regulatory power over monopolistic corporations through antitrust enforcement, earning him the moniker "trust-buster" for actions like the dissolution of the Northern Securities Company.[5] His domestic agenda, known as the Square Deal, sought to balance interests of labor, business, and consumers via reforms in food safety, consumer protection, and railroad regulation.[6] In conservation, he championed the protection of natural resources, establishing the U.S. Forest Service, designating 150 national forests, 51 federal bird reserves, four national game preserves, five national parks, and 18 national monuments, thereby preserving over 230 million acres of public land.[7] Abroad, Roosevelt pursued an assertive foreign policy encapsulated in his maxim to "speak softly and carry a big stick," facilitating the construction of the Panama Canal after supporting Panama's independence from Colombia and mediating the end of the Russo-Japanese War in 1905, for which he became the first American to receive the Nobel Peace Prize.[8] His military exploits included leading the Rough Riders regiment during the Spanish-American War, where he earned recognition for charging up Kettle Hill in the Battle of San Juan Hill.[9] Roosevelt's energetic persona and prolific writings, including over 35 books on history, nature, and policy, influenced the modern expansion of presidential authority and public engagement with environmental stewardship, though his interventionist approach drew criticism for imperial overreach in Latin America and the Philippines.[5][10]Places
Geographical locations and regions
Turkey (Türkiye) is a transcontinental country located primarily in Western Asia, with a small portion in Southeastern Europe. Its Asian territory occupies the Anatolian Peninsula, while the European part, known as East Thrace, lies west of the Bosporus Strait. Geographically, it is situated between latitudes 36° and 42° N and longitudes 26° and 45° E.[11] The country covers a total area of 783,562 square kilometers, of which 769,632 square kilometers is land and 13,930 square kilometers is water. It shares land borders totaling 2,816 kilometers with eight countries: Armenia (268 km), Azerbaijan (482 km), Bulgaria (240 km), Georgia (273 km), Greece (203 km), Iran (534 km), Iraq (367 km), and Syria (449 km). Turkey's coastline measures 7,200 kilometers along the Black Sea to the north, the Aegean Sea to the west, and the Mediterranean Sea to the south.[11] Turkey features diverse terrain including high central plateaus, narrow coastal plains, and several mountain ranges such as the Taurus Mountains in the south and the Pontic Mountains along the Black Sea coast. Mount Ararat, at 5,137 meters, is the highest point, located in Eastern Anatolia near the border with Armenia and Iran. The country is prone to earthquakes due to its position on multiple tectonic plates, including the Anatolian Plate.[11] For statistical and developmental purposes, Turkey is divided into seven geographical regions: Marmara (northwest, including Istanbul), Aegean (west, along the Aegean coast), Mediterranean (south, with subtropical climate), Black Sea (north, humid and forested), Central Anatolia (interior plateau, home to Ankara), Eastern Anatolia (northeast, mountainous and coldest region), and Southeastern Anatolia (southeast, semi-arid with Euphrates and Tigris rivers). These regions, established in the 1960s by Turkey's State Planning Organization, reflect variations in climate, topography, agriculture, and economy, with the Marmara and Aegean regions being more industrialized and the eastern regions more agrarian and pastoral.[11][12]Administrative divisions
Turkey is divided into 81 provinces (Turkish: iller or il), each administered by a governor (vali) appointed by the President of Turkey and responsible for implementing central government policies at the provincial level. These provinces vary significantly in size, population, and economic importance, with Istanbul Province being the most populous at over 15 million residents as of 2023 estimates, while provinces like Tunceli have fewer than 100,000 inhabitants.[13] The provincial boundaries were largely established during the early Republican era, with the last additions occurring in 1995 when 9 new provinces were created from existing ones to address regional development needs. Each province is subdivided into districts (ilçeler), numbering 973 as of 2025, each led by a district governor (kaymakam) also appointed centrally to oversee local administration, security, and public services.[14] Districts handle day-to-day governance, including civil registration, education oversight, and law enforcement coordination, but lack fiscal autonomy as budgets derive from provincial allocations tied to national funds. The creation of new districts surged after 2012 legislative changes, increasing from around 850 to the current figure to decentralize administration in growing urban areas, though critics argue this fragments governance without enhancing local decision-making.[15] At the sub-district level, urban areas are organized into neighborhoods (mahalleler), totaling approximately 32,000, which serve as the basic unit for municipal services like waste collection and zoning, while rural areas feature villages (köyler), numbering around 18,000, focused on agricultural administration and basic infrastructure.[16] Local self-government operates parallel via elected municipalities: 30 metropolitan municipalities (büyükşehir belediyeleri) in major provinces manage extended urban services since expansions in 2012 and 2014, alongside 51 provincial municipalities and 922 district municipalities.[17] For statistical purposes, the Turkish Statistical Institute (TÜİK) groups provinces into 7 regions—Central Anatolia, Eastern Anatolia, Black Sea, Aegean, Mediterranean, Southeastern Anatolia, and Marmara—but these lack formal administrative powers.[18] This structure reflects a unitary state emphasizing central control, with limited devolution to elected bodies amid ongoing debates over efficiency and regional disparities.People
Historical and political figures
Mustafa Kemal Atatürk (1881–1938) founded the Republic of Turkey on October 29, 1923, following the Turkish War of Independence and the dissolution of the Ottoman Empire after World War I.[19] As the first president from 1923 until his death, he implemented sweeping reforms including the abolition of the caliphate in 1924, adoption of a secular constitution, introduction of the Latin alphabet in 1928, and granting women suffrage in 1934, aiming to modernize Turkey along Western lines while emphasizing Turkish nationalism.[19] His military leadership, notably at the Battle of Gallipoli in 1915, established his reputation as a national hero.[19] Süleyman I, known as Suleiman the Magnificent (1494/1495–1566), ruled the Ottoman Empire from 1520 to 1566, marking the peak of its territorial expansion and cultural flourishing.[20] During his 46-year reign, the empire conquered Belgrade in 1521, Rhodes in 1522, and much of Hungary after the Battle of Mohács in 1526, while he also reformed legal codes, earning the epithet "the Lawgiver" in Turkish.[20] Süleyman's era saw advancements in architecture, poetry, and administration, with Istanbul becoming a center of Islamic and Renaissance-influenced arts.[20] İsmet İnönü (1884–1973) served as the second president of Turkey from 1938 to 1950, succeeding Atatürk and maintaining continuity in secular republican policies during World War II, when Turkey adopted strict neutrality until joining the Allies in February 1945.[21] As a key commander in the War of Independence and chief negotiator of the Treaty of Lausanne in 1923, which defined modern Turkey's borders, he later transitioned the country to multiparty democracy in 1946, allowing the opposition Democratic Party to win elections in 1950.[21] Recep Tayyip Erdoğan has led Turkey as president since August 2014, following his tenure as prime minister from 2003 to 2014 with the Justice and Development Party (AKP), which he co-founded in 2001.[22] Elected mayor of Istanbul in 1994, his national rise capitalized on economic growth policies that expanded GDP from $230 billion in 2002 to over $900 billion by 2013, alongside infrastructure projects like high-speed rail and airports.[22] A 2017 constitutional referendum shifted Turkey to a presidential system, consolidating executive powers, which Erdoğan won with 52% of the vote in the 2018 election.[22]Other notable individuals
Science, technology, and mathematics
Computing and software
In computer science, "TR" most commonly denotes a technical report, a document that details research findings, methodologies, and preliminary results, often published by universities or organizations before formal peer review. These reports facilitate rapid dissemination of advancements in areas such as algorithms, systems, and artificial intelligence; for example, Purdue University's Department of Computer Science assigns sequential TR numbers to such publications, with archives dating back decades.[27] Similarly, Stanford maintains an extensive collection of computer science TRs summarizing collaborative digital library projects funded by agencies like ARPA.[28] Technical reports differ from journal articles by prioritizing completeness over conciseness, typically including abstracts, methodologies, results, and references, as outlined in guidelines from institutions like UMBC.[29] The tr utility in Unix-like operating systems, short for "translate" or "transliterate," processes text streams by substituting, deleting, or compressing characters according to specified rules. Introduced in early Unix versions, it supports operations like converting uppercase to lowercase (e.g.,tr 'A-Z' 'a-z') or removing duplicates (e.g., tr -s ' '), making it essential for scripting and data transformation tasks.[30] Its efficiency stems from stream-based processing without loading entire files into memory, though it lacks advanced pattern matching found in tools like sed or awk.
In markup languages, particularly HTML, specifies a table row element, grouping cells ( for data or for headers) within a structure. Defined in HTML standards since version 2.0, it enables tabular data presentation on the web, with attributes like rowspan or colspan for spanning multiple rows or columns; browsers render it as a horizontal row, often with default styling for zebra striping in modern CSS frameworks.[31]
Other uses include Tools Release in software development, referring to bundled updates for development toolkits, and Task Register in processor architectures, a hardware register holding task state pointers in segmented memory models like x86.[32][33] Less commonly, TR designates W3C's technical report namespace (w3.org/TR/), hosting draft and final specifications regardless of maturity level.[34]
Biology and medicine
Tricuspid regurgitation (TR), also known as tricuspid insufficiency, is a cardiac valvular abnormality in which the tricuspid valve fails to close fully during systole, permitting retrograde blood flow from the right ventricle into the right atrium.[35] This condition affects approximately 0.8% of the general population, with prevalence increasing to over 10% in individuals aged 75 years and older, often secondary to left-sided heart disease such as mitral regurgitation or aortic stenosis rather than primary valve pathology.[35] Severe TR correlates with reduced survival rates, with one-year mortality exceeding 30% in symptomatic cases untreated by intervention, underscoring its prognostic significance independent of left ventricular function.[35] Diagnosis of TR typically involves echocardiography, where regurgitant volume exceeding 45 mL per beat or effective regurgitant orifice area greater than 0.4 cm² classifies it as severe, guiding decisions for transcatheter or surgical repair. Recent advancements include transcatheter edge-to-edge repair systems, which have demonstrated feasibility in reducing TR severity by at least one grade in over 80% of high-risk patients ineligible for open surgery, as evidenced by trials initiated around 2018.[36] In endocrinology, thyroid hormone receptors (TRα and TRβ) are ligand-activated transcription factors belonging to the nuclear receptor superfamily, encoded by the THRA and THRB genes on chromosomes 17 and 3, respectively.[37] These receptors bind triiodothyronine (T3) with high affinity, modulating gene expression in tissues such as liver, heart, and brain to regulate metabolism, development, and homeostasis; mutations in TRβ, for instance, cause resistance to thyroid hormone syndrome, characterized by elevated serum T3 and T4 levels without thyrotoxic symptoms due to impaired receptor responsiveness.[37] In neuroimaging, repetition time (TR) denotes the interval between successive radiofrequency pulses in magnetic resonance imaging sequences, typically ranging from milliseconds to seconds, which influences signal-to-noise ratio and contrast weighting—shorter TR values enhance T1 weighting for anatomical detail, while longer TR minimizes it to emphasize T2 effects.[38] Optimal TR selection, often 500-2000 ms for T1-weighted scans, balances scan efficiency with diagnostic yield, as deviations can artifactually alter tissue differentiation.[38] Terminal repeats (TR) in molecular biology refer to short, identical DNA sequences flanking retroviral or transposon elements, facilitating integration into host genomes via reverse transcription; for example, long terminal repeats (LTRs) in retroviruses like HIV contain promoter and enhancer regions essential for viral replication.[37] These structures, averaging 200-1000 base pairs, exhibit bidirectional promoters that drive proviral transcription post-integration.[37]Physics and engineering
In physics, particularly in quantum mechanics and operator theory, Tr denotes the trace of a matrix or linear operator, defined as the sum of the elements along its principal diagonal, which is invariant under basis changes and basis-independent. This quantity is fundamental for computing quantities such as the partition function in statistical mechanics, given by Z = \mathrm{Tr}(e^{-\beta H}), where H is the Hamiltonian and \beta = 1/(kT), and for expectation values of observables in density matrix formalism, \langle O \rangle = \mathrm{Tr}(\rho O), with \rho the density operator./01%3A_Linear_Vector_Spaces_and_Hilbert_Space/1.05%3A_The_Trace_and_Determinant_of_an_Operator) Transition radiation (TR) refers to the electromagnetic radiation emitted by a relativistic charged particle when it crosses the interface between two media with differing dielectric constants, such as vacuum and a solid or between two solids. Predicted theoretically in 1945 and experimentally observed in the 1950s, TR produces X-ray or optical photons whose yield increases with particle Lorentz factor \gamma, typically requiring \gamma > 100 for significant emission; it is exploited in particle detectors like transition radiation detectors (TRDs) for distinguishing electrons from hadrons based on velocity-dependent signal strength. In mechanical and HVAC engineering, TR stands for ton of refrigeration, a unit of cooling capacity defined as the rate of heat removal required to melt 1 short ton (2000 lb or 907 kg) of ice at 0°C in 24 hours, equivalent to 12,000 BTU/h (British thermal units per hour) or approximately 3.517 kW. This standard, originating from early 20th-century ice-making practices, quantifies chiller and air conditioning system performance; for instance, a 100 TR system removes 1.2 million BTU/h, with conversions to SI units involving the latent heat of fusion of water at 334 kJ/kg.[39] In engineering documentation and research, TR abbreviates technical report, a structured document detailing the objectives, methodology, findings, and recommendations of a specific project, experiment, or study, often produced by government agencies, corporations, or academic institutions to disseminate non-peer-reviewed but verifiable technical data. Examples include U.S. Department of Energy TRs on materials testing or NASA TRs on propulsion systems, which follow standardized formats with abstracts, results sections, and appendices for reproducibility.[40]Other technical uses
In standards development, TR designates a technical report, an informative document that conveys research findings, analysis, or guidance without imposing normative requirements, distinguishing it from binding standards or specifications.[41] Such reports are issued by organizations like the International Organization for Standardization (ISO), where ISO/TR-series documents provide supplementary data, surveys, or tutorials to aid standard creation, as seen in ISO/TR 18394:2016 on Auger electron spectroscopy for chemical analysis.[42][43] Similarly, Ecma International publishes TRs to detail technical aspects of standardization efforts, emphasizing their non-mandatory nature.[44] In research and engineering contexts, TR commonly abbreviates technical report, a formal publication format for disseminating preliminary or specialized results from projects, often numbered sequentially within institutions (e.g., MIT's TR series or IEEE technical reports).[29] These documents typically include methodology, data, and conclusions but lack the peer-review rigor of journal articles, serving as interim outputs in fields like computer science or materials engineering.[45] In telecommunications standards bodies such as 3GPP, TRs precede technical specifications (TS) by outlining requirements and feasibility studies.[46] The World Wide Web Consortium (W3C) employs /TR/ in its URI structure for technical reports, encompassing working drafts, candidate recommendations, and final publications that evolve toward recommendations.[34] This usage underscores TR's role in iterative technical documentation, prioritizing factual dissemination over enforceability.Businesses and organizations
Companies and corporations
Thomson Reuters Corporation (commonly abbreviated TR) is a Canadian multinational conglomerate specializing in financial markets data, legal research, and professional services, formed by the 2008 merger of Thomson Corporation and Reuters Group. Headquartered in Toronto, Ontario, it reported revenues of $6.8 billion in 2023, with operations in over 100 countries and a workforce exceeding 25,000 employees. Tootsie Roll Industries, Inc. (NYSE: TR) is an American confectionery manufacturer founded in 1896, producing brands such as Tootsie Rolls, Tootsie Pops, and Dots, with annual sales around $700 million as of 2022. The company maintains a family-controlled structure and focuses on classic candy products distributed primarily in North America.[47] TRW Inc. was an American industrial conglomerate established in 1901 as Thompson Products, evolving through mergers to become a leader in aerospace systems, automotive components, and defense technologies until its $5.1 billion acquisition by Northrop Grumman in 2002. At its peak, TRW employed over 100,000 people and contributed to projects like the Apollo space program and early automotive airbags. The TRW brand persists in aftermarket automotive parts under ZF Friedrichshafen.[48][49]Non-profit and other organizations
Team Rubicon (TR) is a veteran-led 501(c)(3) non-profit organization that mobilizes military veterans, first responders, and skilled civilians for disaster response, community rebuilding, and humanitarian aid. Founded on January 8, 2010, by former U.S. Marine Corps intelligence officer Jake Wood and others in response to the Haiti earthquake, the group initially deployed to Port-au-Prince to clear debris and deliver medical supplies, marking the first of its "Go Days" for rapid mobilization.[50][51] By 2025, Team Rubicon had over 180,000 registered volunteers, with operations in all 50 U.S. states and more than 20 countries, including responses to events like Hurricane Helene in 2024 and glacial floods in Alaska.[52] The organization emphasizes leveraging veterans' training in logistics, medical care, and engineering for efficient, high-impact interventions, often partnering with government agencies and corporations like Ford for equipment and funding.[53] Other non-profits using the TR designation include smaller entities like TR's Cancer Fighters, Inc., a fundraising charity established to support cancer patients and research through community events and donations.[54] Various charitable trusts abbreviated as "TR," such as the Do Good Charitable Trust, operate under IRS 501(c)(3) status for philanthropic purposes but lack the scale or public prominence of Team Rubicon.[55] These trusts typically focus on targeted giving, such as family foundations or specific causes, without a unified national or international presence.Transportation
Vehicles and models
The Triumph TR series comprises a range of two-seat sports cars produced by the Triumph Motor Company from 1953 to 1981, emphasizing open-top roadsters with inline engines, rear-wheel drive, and a focus on export markets, particularly the United States.[56] Over 250,000 units were sold across the models, establishing the TR as one of the most successful British sports car lines of the postwar era, known for agile handling derived from a live-axle chassis and competitive pricing relative to rivals like the MG MGA.[56] Early models featured a 1,991 cc inline-four engine, evolving from 90 bhp in the TR2 to over 100 bhp with optional overdrive and disc brakes by the TR3A.[57] The TR4 introduced a more aerodynamic body with an optional hardtop, while the TR4A added independent rear suspension via a Chapman strut design, improving ride quality.[57] The TR5 and TR250 marked the shift to a 2,498 cc six-cylinder engine, with fuel injection on the UK-market TR5 for 145 bhp, though the US TR250 used carburetors to meet emissions standards.[57]| Model | Production Years | Engine and Output | Production Numbers | Notes |
|---|---|---|---|---|
| TR2 | 1953–1955 | 1,991 cc I4, 90 bhp | 8,628 | Original roadster with separate chassis; launched at 1953 Earls Court Motor Show.[57] [58] |
| TR3 | 1955–1957 | 1,991 cc I4, 95 bhp | 13,377 | Increased power; front disc brakes from late 1957.[57] |
| TR3A | 1958–1961 | 1,991 cc or 2,138 cc I4, up to 108 bhp | 58,236 | Facelifted grille; optional larger engine.[57] |
| TR3B | 1962 | 2,138 cc I4, 106 bhp | 3,331 | US-market only; updated with TR4 components.[57] |
| TR4 | 1961–1965 | 2,138 cc I4, 104 bhp | 40,253 | Unitary body; wind-up windows and rack-and-pinion steering.[57] |
| TR4A | 1965–1967 | 2,138 cc I4, 104 bhp | 28,465 | Independent rear suspension; optional IRS for US.[57] |
| TR5 | 1967–1968 | 2,498 cc I6, 145 bhp (fuel-injected) | 2,947 | UK-only six-cylinder; overdrive standard.[57] |
| TR250 | 1967–1968 | 2,498 cc I6, 111 bhp (carbureted) | 8,484 | US version of TR5 for emissions compliance.[57] |
Infrastructure and systems
In the context of public transportation, TR designates aerial tramway as a transit mode in the U.S. Federal Transit Administration's National Transit Database (NTD), encompassing systems where unpowered passenger cabins are suspended from overhead cables and propelled between terminals by external motors rather than onboard power.[59] These systems operate as reversible setups, with one or two cabins shuttling back and forth along a fixed route, supported by stationary track cables strung between towers and driven by a separate haul rope looped around drive sheaves at the terminals.[60] Aerial tramway infrastructure typically includes two end terminals housing drive machinery, counterweights, and loading/unloading platforms; intermediate support towers spaced 150 to 1,000 meters apart to maintain cable tension and alignment; and multi-strand steel cables rated for loads exceeding 100 metric tons per cabin, with haul ropes often featuring anti-rotation designs for stability.[59] The route length, measured as line miles, follows the path of the towers from terminal to terminal, enabling spans up to several kilometers while navigating steep terrain or urban obstacles impassable by ground vehicles.[59] Power systems rely on electric motors at one terminal, achieving speeds of 5 to 12 meters per second, with redundancy features like backup diesel generators ensuring operational continuity during outages.[60] Safety and maintenance protocols for TR systems emphasize cable inspections every 1,000 to 2,000 operating hours, tower foundation stability against wind loads up to 200 km/h, and emergency evacuation mechanisms such as descent ropes or helicopter access points.[61] Unlike detachable gondola systems, aerial tramways use fixed grips, limiting intermediate stops but providing higher capacity per cabin (up to 150 passengers) and lower energy use per passenger-kilometer due to centralized propulsion.[62] Deployment costs range from $10 to $30 million per kilometer, influenced by span length and terrain, with lifespans exceeding 40 years when cables are replaced every 20-25 years.[63]Language and linguistics
Abbreviations and symbols
In linguistic glossing, particularly within interlinear morpheme glosses used to analyze grammatical structures across languages, TR abbreviates "transitive," denoting transitive verbs or transitivizing morphemes. This convention is standardized in resources like the Leipzig Glossing Rules, which promote uniformity in abbreviations among linguists to facilitate cross-linguistic comparisons.[64] The abbreviation tr. appears in dictionaries, editorial notes, and bibliographic references to signify "translated," "translation," or "translator," often indicating the source of rendered text from another language.[65] It may also denote "transitive" in grammatical contexts, such as labeling verb valency.[66] In international standards for language identification, tr is the ISO 639-1 alpha-2 code for Turkish (Türkçe), used in computing, metadata, and localization to tag content in the Turkish language.[67] This code aligns with the Turkic language family and supports digital processing of Turkish texts, distinct from the ISO 3166-1 alpha-2 country code TR for Turkey.[68]Grammatical and orthographic uses
In grammatical analysis, particularly in dictionary entries and linguistic descriptions, "tr." serves as the standard abbreviation for "transitive," denoting verbs that require a direct object to complete their meaning. For instance, dictionaries label such verbs with "tr." to distinguish them from intransitive ones marked "intr.," aiding users in understanding syntactic behavior.[69] [66] In orthographic proofreading and copyediting, "tr" or "tr." functions as a correction mark signifying "transpose," which directs the reversal of adjacent or specified elements, such as letters within a word (e.g., "recieve" to "receive") or words in a phrase, to rectify errors in sequence without rewriting. This mark, often accompanied by a loop or underline in margins or text, streamlines editorial revisions in print and manuscript preparation.[70][71] Additionally, in etymological and bibliographic contexts within linguistic resources, "tr." abbreviates "translator," "translated," or "translation," indicating the source language or human involvement in rendering texts, as seen in reference works attributing origins or adaptations.[65] [66]Arts and entertainment
Music and albums
- TR/ST: Canadian electronic music project founded by Robert Alfons, initially as a duo with Maya Postepski before becoming a solo endeavor; the project has produced synthpop and darkwave albums including the debut TRST (February 28, 2012), Joyland (2014), The Destroyer – Part 1 and Part 2 (2019), and Performance (September 13, 2024).[72][73][74]
- TR (Tolvai Reni album): Debut studio album by Hungarian singer Tolvai Reni, released in 2012 following her win on Megasztár talent show; features pop tracks such as "Új Reni" and "Fékezz".[75]
- TR (British rapper): Stage name of UK drill and hip-hop artist TR, with releases including the mixtape The Streets (2025) and singles like "L4P" and "Mason Mount".[76]
- TR/ST EP: Extended play by TR/ST, surprise-released on January 26, 2024, containing tracks "Robrash", "Run" (featuring Cecile Believe), "Evercall", and a cover of Pet Shop Boys' "Being Boring" (featuring Jake Shears).[72][74]