PLP
The Parliamentary Labour Party (PLP) is the organized group of all Labour Members of Parliament serving in the United Kingdom's House of Commons.[1] As the parliamentary component of the Labour Party, the PLP coordinates legislative strategy, enforces voting discipline via whips, and engages in debates and committees to advance or oppose government measures depending on whether Labour holds power. It convenes weekly under a chair elected by its members—currently Jessica Morden as of 2024—and maintains an executive committee for internal governance, distinct from the party's National Executive Committee to focus on Commons-specific operations. Following the July 2024 general election, the PLP expanded to 412 MPs, forming the largest parliamentary majority since 1997 and enabling implementation of policies such as the establishment of Great British Energy.[2] The PLP's defining characteristics include its emphasis on pragmatic governance suited to parliamentary constraints, often placing it at odds with more ideological elements in the wider Labour movement, as evidenced by recurrent leadership contests and deselections. Notable achievements encompass key legislative pushes during Labour governments, including the nationalization of industries post-1945 and welfare reforms under Tony Blair, though these have drawn criticism for diverging from socialist first principles toward market-oriented approaches. Controversies have centered on internal power struggles, such as the 1981 defection of moderate MPs to form the Social Democratic Party amid perceptions of left-wing dominance, and the 2016 no-confidence motion against Jeremy Corbyn passed by 172 to 40 PLP members, reflecting empirical concerns over electoral viability and institutional failings later substantiated by independent investigations into party processes.[3][4]Biochemistry
Pyridoxal phosphate
Pyridoxal 5'-phosphate (PLP), the primary active coenzyme form of vitamin B6, consists of a pyridine ring substituted with an aldehyde at the 4-position, a hydroxymethyl group at the 5-position esterified to phosphate, and a phenolic hydroxy group at the 3-position.[5] This structure enables PLP to form Schiff bases with amino groups of substrates, facilitating catalysis in over 140 distinct enzymatic activities, which represent approximately 4% of all classified enzymes.[6] These enzymes predominate in amino acid metabolism but extend to neurotransmitter biosynthesis, glycogen degradation, and heme production.[5] PLP-dependent enzymes are ubiquitous across organisms, comprising about 1.5% of genes in free-living prokaryotes and fewer in eukaryotes, reflecting their conserved role in core metabolic processes.[6] De novo biosynthesis of PLP occurs in bacteria, plants, and fungi but not in humans or other animals, which depend on dietary intake of vitamin B6 vitamers (pyridoxine, pyridoxal, pyridoxamine).[5] Prokaryotic pathways, such as in Escherichia coli, utilize deoxyxylulose 5-phosphate and 4-phosphohydroxy-L-threonine via enzymes PDXA and PDXJ in a DXP-dependent route, while eukaryotes employ a DXP-independent path with PDX1/PDX2 using glyceraldehyde 3-phosphate, ribose 5-phosphate, and glutamine.[5] In salvage pathways across species, non-phosphorylated vitamers are first phosphorylated by pyridoxal kinase (PLK), then oxidized by FMN-dependent pyridox(am)ine 5'-phosphate oxidase (PNPOx) to yield PLP from pyridoxine 5'-phosphate (PNP) or pyridoxamine 5'-phosphate (PMP).[7] Human PNPOx, a homodimeric enzyme encoded on chromosome 17q21.2, favors this conversion in liver, muscle, and kidneys, with mutations linked to epileptic encephalopathy due to impaired PLP production.[7] The catalytic mechanism of PLP enzymes hinges on external aldimine formation between PLP's aldehyde and the substrate's amino group, followed by proton abstraction to generate a stabilized α-carbanion intermediate, often delocalized via the pyridine ring and imine.[8] This enables diverse reactions, including transamination (e.g., aspartate aminotransferase, EC 2.6.1.1, interconverting aspartate and α-ketoglutarate), decarboxylation (e.g., aromatic L-amino acid decarboxylase producing dopamine from L-DOPA or serotonin from 5-hydroxytryptophan), racemization (L- to D-amino acid conversion), β- and γ-eliminations/substitutions, retro-aldol cleavages, and oxidative deaminations.[5][8] For instance, serine hydroxymethyltransferase (EC 2.1.2.1) uses PLP for retro-aldol-like transfer of hydroxymethyl groups in one-carbon metabolism, while kynureninase performs a retro-Claisen cleavage of kynurenine to anthranilate and alanine.[6][8] PLP also activates glycogen phosphorylase by forming a covalent phosphohistidine intermediate and supports δ-aminolevulinic acid synthase in heme biosynthesis via decarboxylative condensation.[5] Deficiency in PLP availability, often from genetic PNPOx defects or dietary inadequacy, disrupts these pathways, leading to neurological issues like seizures and sideroblastic anemia due to impaired heme synthesis.[5]Politics
Parliamentary Labour Party
The Parliamentary Labour Party (PLP) is the organized group of all Labour Party Members of Parliament (MPs) serving in the House of Commons of the United Kingdom Parliament. It functions as the parliamentary wing of the Labour Party, responsible for coordinating the legislative activities, enforcing party discipline through whips, and representing MPs' interests in internal party decisions. The PLP operates semi-autonomously from the party's National Executive Committee (NEC) and annual conference, holding its own weekly meetings to deliberate on bills, government policy, and strategy.[9] Founded in 1906 following the election of the first Labour MPs in the 1906 general election, the PLP initially comprised a small number of representatives from trade unions and socialist societies. It grew alongside the party's expansion, reaching over 400 members after Labour's landslide victory in the July 2024 general election, where it secured 411 seats out of 650, granting a working majority of 161 seats. This numerical dominance has positioned the PLP as the backbone of Prime Minister Keir Starmer's government, tasked with passing legislation such as the King's Speech commitments on economic stability and public service reform. The PLP elects its officers, including a chair (typically a senior MP) and an executive committee of around 20 members, to oversee its operations and liaise with the party leadership.[9][10][11] In leadership elections, the PLP wields significant influence through nominations—requiring support from at least 15% of its MPs for candidates—and by shaping the electorate's preferences via endorsements and internal debates. For instance, in the 2020 leadership contest, Keir Starmer garnered 56% of PLP nominations, contributing to his victory over more left-wing rivals. The PLP has historically enforced accountability, as evidenced by its near-unanimous no-confidence motion against Jeremy Corbyn in June 2016 following Labour's poor local election results, though Corbyn retained the leadership via a member ballot. Recent tensions include allegations of irregularities in candidate selections for the 2024 election, where Starmer allies reportedly favored moderate figures, prompting claims of vote-rigging in shortlisting processes that sidelined left-leaning aspirants; investigations by the party's governance body found procedural flaws but no widespread fraud.[12][13] Ideological divisions within the PLP have periodically undermined party unity, with centrist MPs often clashing with the Corbynite faction over issues like Brexit and antisemitism definitions. During Corbyn's tenure (2015–2020), over 170 PLP members signed a 2015 letter criticizing his leadership as detached from mainstream voter concerns, reflecting empirical polling data showing Labour's support dipping below 30% amid internal strife. Under Starmer, the PLP has prioritized policy discipline, expelling or suspending around 20 MPs since 2020 for breaches including proscribed group affiliations, though critics argue this centralization stifles debate and favors electoral pragmatism over grassroots input. As of October 2025, the PLP continues to navigate post-election challenges, including a deputy leadership contest triggered by Angela Rayner's resignation, won by Lucy Powell with pledges to counter opposition narratives.[13][14]Progressive Labor Party (United States)
The Progressive Labor Party (PLP) emerged in the early 1960s as an anti-revisionist splinter from the Communist Party USA (CPUSA), driven by opposition to the de-Stalinization policies articulated by Nikita Khrushchev in his February 1956 "secret speech" denouncing Stalin's cult of personality and the ensuing doctrinal shifts toward peaceful coexistence with capitalism.[15] Dissident CPUSA members, including figures like Milton Howard and Harry Levin, formed the Progressive Labor Movement (PLM) in January 1962 to advocate for a return to revolutionary Marxism-Leninism, rejecting what they viewed as the CPUSA's accommodation to U.S. imperialism and liberal reforms.[16] The group reorganized as the full Progressive Labor Party by its founding convention in 1965, with an initial membership of approximately 200, primarily ex-CPUSA cadres and their relatives who emphasized vanguard party discipline and proletarian internationalism over electoral gradualism.[16] Early PLP ideology aligned closely with Mao Zedong's China, positioning it as a Maoist faction critical of Soviet "revisionism" and supportive of China's Cultural Revolution as a model for combating bureaucratic degeneration within communist movements.[15] During the late 1960s, PLP sought to infiltrate and influence the New Left, particularly through entry into Students for a Democratic Society (SDS), where it formed the Worker-Student Alliance faction starting around 1966.[17] By 1968, PLP membership had grown modestly to about 325, with roughly half concentrated in New York City, enabling it to gain a plurality in SDS national leadership at the 1969 convention through advocacy for anti-imperialist worker organizing over identity-based or nationalist tactics.[16] However, PLP's insistence on rejecting alliances with "bourgeois" nationalists and prioritizing class struggle led to its effective expulsion from SDS, as opponents formed rival groups like the Revolutionary Youth Movement, fracturing the organization and limiting PLP's broader New Left impact.[17] The party maintained a focus on industrial base-building, publishing its newspaper Challenge (first issue 1964) to promote anti-war agitation, workplace agitation, and criticism of U.S. involvement in Vietnam, while opposing conscription—many members were drafted despite resistance, viewing military service as a site for revolutionary agitation.[18] Ideologically, PLP evolved in the 1970s by rejecting Maoism following China's post-Mao shift under Deng Xiaoping toward market-oriented reforms, which PLP deemed capitalist restoration akin to Soviet revisionism; by 1976, it critiqued the two-stage theory of socialism preceding communism, advocating direct transition to a classless society without intermediate "socialist" states prone to degeneration.[19] Core tenets include democratic centralism for party organization, anti-racism framed as a class weapon against capitalist division rather than an autonomous struggle, and unrelenting opposition to imperialism, fascism, and borders as tools of exploitation.[20] The party has experienced internal purges and minor splits over tactical questions, such as the 1970s debates on China's reliability, but retained a small, disciplined cadre emphasizing criticism and self-criticism.[21] Today, PLP remains a marginal revolutionary communist group, active in sporadic protests against U.S. foreign policy (e.g., Gaza-related actions in October 2024), workplace organizing, and campus agitation, distributing Challenge at events drawing hundreds but without disclosed membership figures beyond historical estimates suggesting persistence at low hundreds.[22] Its influence is confined to niche leftist circles, with no electoral success or significant institutional penetration, prioritizing long-term revolutionary preparation over reformist gains.[18]Progressive Liberal Party (Bahamas)
The Progressive Liberal Party (PLP) is a centre-left political party in the Bahamas, established on November 23, 1953, as the nation's first organized party advocating for political representation by the black majority against the white oligarchy represented by the United Bahamian Party.[23] Founded by figures including William Cartwright and Cyril Stevenson, the PLP emphasized progressive reforms, social equity, and self-governance in a colony where voting rights were limited by property qualifications favoring elites.[23] Under early leadership, including Lynden Pindling from 1956, the party mobilized support among urban workers and rural communities, challenging colonial-era disenfranchisement.[24] The PLP achieved a breakthrough in the January 10, 1967, general election, securing 18 seats in a tie with the United Bahamian Party but forming a government with independent support, ushering in majority rule and ending minority white dominance in the House of Assembly.[23] Pindling became Premier, advancing constitutional reforms that expanded suffrage and public services. The party solidified power in the 1968 election with 29 seats and led the Bahamas to independence from Britain on July 10, 1973, with Pindling as the first Prime Minister.[24] Subsequent victories in 1972 (33 seats), 1977 (30 seats), 1982 (32 seats), and a narrow 1987 win (31 seats) entrenched PLP governance, focusing on nationalization of utilities, education expansion, and infrastructure like the New Providence highway system.[25] Pindling's long tenure faced scrutiny in the 1980s over allegations of corruption tied to drug trafficking, with a 1984 Commission of Inquiry documenting unexplained wealth among officials and police complicity in smuggling operations, though Pindling denied personal involvement and attributed claims to political opponents.[26][27] These issues contributed to the PLP's defeat in the 1992 election, where it won only 17 seats against the Free National Movement's 32, ending 25 years in power.[28] Perry Christie revived the party, leading it to victory in 2002 (29 seats) with policies on tourism diversification and crime reduction, but losses followed in 2007 (18 seats) and after the 2012 win (32 seats) due to economic critiques.[29] The PLP returned to opposition after the 2017 election (24 seats to FNM's 35) but capitalized on dissatisfaction with the incumbent's handling of Hurricane Dorian in 2019 and the COVID-19 pandemic, winning 32 seats in the September 16, 2021, election under Philip "Brave" Davis, who became Prime Minister.[30] Davis's administration prioritized economic stabilization, job creation through a 10-point plan targeting healthcare, education, and renewable energy, alongside relief for small businesses and vaccine distribution post-pandemic.[31] As of 2025, the PLP holds power ahead of the 2026 election, having ratified candidates and emphasized inclusive growth amid preparations for by-elections.[32] Ideologically, the PLP positions itself as populist and social liberal, promoting Bahamian empowerment, wealth redistribution, and public welfare while critiquing elite capture of resources.[23] Its platform has historically included land reforms for majority access and anti-corruption measures, though implementation has varied, with post-2021 focus on national ownership laws to prioritize locals in tourism and real estate.[31] The party alternates with the more conservative Free National Movement in a two-party system, reflecting Bahamas' stable parliamentary democracy since independence.[23]Business and Industry
Preformed Line Products
Preformed Line Products Company (PLPC) is a designer, manufacturer, and supplier of hardware and systems used in the construction and maintenance of overhead and underground electric, telecommunications, and fiber optic networks.[33] Founded in 1947 and headquartered in Mayfield Village, Ohio, the company specializes in preformed grips, dead-ends, suspension systems, and vibration control products that enhance the reliability and longevity of transmission and distribution lines.[34] [35] With operations spanning over 20 countries, PLP serves utilities, contractors, and renewable energy sectors globally, emphasizing engineered solutions for high-voltage applications and fiber optic deployments.[36] The company's origins trace to inventor Leslie F. Peterson, who developed the first preformed helical grip for securing guy wires on utility poles, addressing failures in traditional clamps.[37] Incorporated in 1947, PLP expanded through Peterson's 28 patents, introducing innovations like the first preformed dead-end for transmission lines in the 1950s and subsequent products for vibration damping and conductor support.[38] By the 1970s, it had established international subsidiaries, including in the UK (1957) and facilities in South Africa (1979), while relocating its U.S. headquarters to Mayfield Village in 1980 for integrated research and manufacturing.[39] [40] The firm went public on NASDAQ in 1980 and has since grown via acquisitions and product diversification into solar and wind farm hardware.[35] PLP's product portfolio includes armor rods for conductor protection, form-fit connectors for fiber optics, and helical fittings that reduce aeolian vibration and galloping in power lines.[34] These preformed items, made from materials like aluminum alloy and stainless steel, are engineered for installation without specialized tools, improving field efficiency over forged alternatives.[41] The company maintains modern manufacturing facilities with ISO-certified quality controls, supporting applications in substations, pole line hardware, and underground cabling.[34] As of 2024, PLPC employs approximately 3,401 people and reports trailing twelve-month revenue of $632.23 million, reflecting steady demand in infrastructure modernization and renewable integration.[42] [43]Computing and E-commerce
Product Listing Page
A product listing page (PLP) is a webpage on an e-commerce platform that presents multiple products in a structured format, typically derived from a specific category, search query, or applied filters, enabling users to scan options before navigating to individual product detail pages (PDPs).[44][45] These pages function as virtual shelves, mimicking physical retail layouts by aggregating inventory data such as images, titles, prices, and basic specifications to facilitate rapid browsing and decision-making.[46][47] PLPs play a pivotal role in the e-commerce conversion funnel, accounting for a significant portion of user engagement; studies indicate they influence up to 40-60% of site sessions by driving product discovery and filtering relevance.[48] Unlike PDPs, which provide in-depth details for single items, PLPs prioritize breadth over depth, often displaying 12-48 products per view with pagination or infinite scroll to handle large catalogs without overwhelming users.[49][50] Effective PLPs incorporate sorting options (e.g., by price ascending/descending, best-sellers, or newest arrivals) and faceted filters for attributes like brand, size, color, or price range, reducing search friction and boosting satisfaction metrics such as time-on-page and click-through rates.[51][52] Core components of a PLP include:- Product cards: Compact modules featuring high-resolution thumbnails (often zoomable on hover), concise titles with key descriptors, current pricing (including discounts or strikethrough originals), stock status indicators, and user-generated elements like star ratings or review counts from aggregated feedback.[46][53]
- Navigation aids: Breadcrumb trails for hierarchy (e.g., Home > Electronics > Smartphones), sidebar or top-bar filters with real-time result counts, and search refinements to refine queries dynamically.[48][52]
- Performance enhancers: Lazy loading for images, schema markup for SEO (e.g., structured data for rich snippets in search results), and A/B-tested layouts like grid vs. list views to accommodate desktop and mobile users, where mobile traffic often exceeds 50% of e-commerce visits.[49][48]