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PSC

Primary sclerosing cholangitis (PSC) is a rare, chronic cholestatic characterized by progressive , , and stricturing of the intrahepatic and extrahepatic bile ducts, resulting in biliary obstruction, , and eventual or . PSC primarily affects men aged 30 to 40 and is frequently associated with , especially , which occurs in up to 80% of cases; the disease's remains unknown but involves immune-mediated destruction of epithelium. It progresses insidiously, often presenting with fatigue, pruritus, , or asymptomatic elevations in , and lacks disease-modifying pharmacotherapies, with offering the only curative option for advanced cases despite high recurrence rates post-transplant. A defining feature of PSC is its elevated risk of , a biliary malignancy with poor prognosis, complicating surveillance and management; while is commonly used symptomatically, randomized trials have shown no survival benefit and potential harm at high doses. The condition's rarity—incidence around 1 per 100,000 in Western populations—hampers research, underscoring ongoing needs for biomarkers, genetic insights from HLA associations, and targeted therapies amid variable natural history, where median survival from diagnosis exceeds 10 years but varies widely.

Business and economics

Personal service corporation

A personal service corporation (PSC) is a corporation under U.S. federal tax law whose principal activity consists of performing personal services in designated fields, including health, law, , , , , , or consulting. The (IRS) defines a PSC as meeting these criteria: its main activities during the applicable testing period involve such services; substantially all services are performed by employee-owners; and those employee-owners own more than 10% of the of the corporation's outstanding on the last day of the testing period. This classification applies specifically to C corporations, reflecting concentrated patterns driven by professional licensing requirements and considerations, which limit stock ownership to qualified practitioners. PSCs face distinct tax treatments compared to other C corporations, including a requirement to adopt a calendar year as their taxable year unless they establish a valid business purpose for an alternative, such as a 52-53-week year ending with reference to December 31. Prior to the Tax Cuts and Jobs Act of 2017, PSCs were subject to a flat corporate income tax rate of 35% on all taxable income, forgoing graduated rates available to other corporations, to curb incentives for professionals to incorporate solely for tax deferral by retaining earnings at lower effective rates. Post-2017, all C corporations, including PSCs, face a uniform flat rate of 21%, though PSCs remain ineligible for certain fiscal year flexibilities and face heightened IRS scrutiny under provisions like IRC Section 269A, which attributes corporate income to personal levels if the entity was formed or availed primarily for tax avoidance. The PSC framework originated within the broader corporate taxation structure of the of 1954, which formalized anti-abuse measures against income shifting in closely held entities, evolving from earlier personal holding company rules aimed at service-based firms with dominant owner-employees. Amendments, including those in the Deficit Reduction Act of 1982 introducing Section 269A, targeted causal mechanisms of , such as disproportionate compensation or deferred distributions in professional practices like firms or medical groups, where revenue derives almost exclusively from rather than depreciable assets. IRS enforcement data highlights ongoing audits of PSCs for unreasonable compensation deductions, with disallowances averaging higher in service-dominated entities due to ownership concentration enabling income recharacterization. This regulatory approach underscores fiscal disincentives for status in personal service fields, channeling many such firms toward pass-through entities where feasible under state professional rules.

Product and service code

The Product and Service Code (PSC) is a standardized four-digit alphanumeric system employed in the U.S. federal to classify products, services, (R&D) activities, and efforts acquired by agencies. These codes facilitate precise categorization of actions reported to the Federal Procurement Data System (FPDS), enabling in by detailing the nature of purchases rather than vendors or agencies involved. Established under the (FAR) and maintained by the Office of Federal Procurement Policy, the PSC structure groups items into 70 major categories (e.g., 10 for weapons, 70 for general-purpose equipment), with subcategories for specificity, supporting empirical tracking of obligations exceeding $755 billion in fiscal year 2024. PSCs play a critical role in FPDS reporting, where they aggregate data for analysis of spending patterns, such as distinctions between Department of Defense (DoD) contracts—often concentrated in codes for weapons (10XXX) and R&D (AXXX)—and civilian agency procurements, which emphasize services like IT (D3XX) and professional support (R4XX). This categorization aids in evaluating bidding competitiveness and contract outcomes, as accurate PSC assignment links requirements to solicitation processes under FAR Part 5, promoting efficiency without presuming systemic inefficiencies absent verified causal evidence. Government Accountability Office (GAO) assessments of FPDS data quality underscore PSCs' utility in identifying reporting gaps that could obscure cost analyses, though direct attribution of overruns requires case-specific validation beyond aggregate coding. The PSC Manual, updated periodically to reflect evolving acquisition needs, underwent a revision in April 2024 via FPDS Version 1.5 Service Pack 21, introducing new codes, modifications, and retirements to accommodate emerging sectors like advanced technology integrations. Post-2020 developments have expanded classifications, including refinements to IT and telecommunications codes (D3XX series) to better capture and cybersecurity procurements amid increased federal reliance on remote capabilities following the onset, though pre-existing end-dating of legacy codes like D305 in 2019 preceded these shifts. such as the PSC Selection Tool further enhance accuracy in code assignment during pre-solicitation phases, linking to object class codes for budgetary alignment.

Government and administration

Public Service Commission

A Public Service Commission (PSC) is an independent tasked with regulating recruitment and appointments to prioritize merit through competitive examinations, thereby insulating administrative roles from political and ensuring bureaucratic competence. These bodies conduct standardized tests, evaluate candidates objectively, and advise on promotions, often enshrined in constitutional or statutory frameworks to maintain . In nations with such commissions, empirical studies indicate that meritocratic systems correlate with reduced risks, as professional criteria for advancement diminish opportunities for and compared to patronage-driven models. In , the (UPSC), established on October 1, 1926, exemplifies this function by administering annual civil services examinations that select officers for key administrative positions based on performance in preliminary, mains, and stages, with over 1 million applicants typically competing for around 1,000 vacancies. The United Kingdom's similarly oversees recruitment to ensure selections occur "on merit on the basis of fair and open competition," auditing processes to enforce neutrality and handling appeals against deviations. In the United States, state-level commissions, such as those in and , manage merit systems for public employees, conducting exams and classifying positions to replace spoils-era favoritism with testable qualifications, though federal oversight falls under the Office of Personnel Management. These commissions fundamentally separate political influence from administrative execution, a rooted in countering historical inefficiencies from politicized bureaucracies where trumped , leading to poorer and higher graft. Data from cross-national analyses show merit protections and impartial yield lower indices, with bureaucracies exhibiting sustained performance gains when promotions hinge on evaluations rather than affiliations. Globally, variations exist—such as constitutionally mandated PSCs in and focusing on oversight amid challenges like cadre imbalances—but core mandates emphasize verifiable competence over equity-driven adjustments that dilute standards.

Police Service Commission

The Police Service Commission (PSC) serves as an independent oversight body in several countries, tasked with managing functions specific to national police forces, including , appointments, promotions, and disciplinary actions. In , the PSC holds constitutional authority under Section 153 of the 1999 Constitution (as amended) and the Police Service Commission (Establishment) Act to exercise powers over the , such as selecting candidates through merit-based processes and enforcing accountability in officer conduct to ensure operational integrity. Similarly, in , the PSC, established via the 1962 Constitution, oversees appointments and promotions for members at or above the rank of , confirmations in office, and procedures for discipline or removal, prioritizing impartiality in security personnel decisions. These commissions operate to insulate police administration from executive interference, fostering selections based on verifiable qualifications rather than . Established in the post-colonial era to professionalize amid transitions to , Nigeria's PSC traces its modern form to the early following in 1960, with statutory reinforcement through subsequent acts despite periodic restructurings, such as its temporary abolition in 1989 before restoration. Jamaica's PSC was formalized at in 1962 as part of broader constitutional safeguards for public institutions, reflecting a deliberate separation of oversight from general administrative control to address colonial-era legacies of politicized policing. This timing aligns with independence movements across the , where such bodies emerged to standardize officer vetting, including background checks for integrity and fitness for roles involving public safety. Unlike general Public Service Commissions, which handle civil service appointments across government departments like administration and infrastructure, Police Service Commissions concentrate on law enforcement-specific domains, such as rigorous security clearances, tactical promotions, and sanctions for breaches like corruption or abuse of authority, excluding routine civil service examinations. In Trinidad and Tobago, for instance, the PSC's jurisdiction is explicitly limited to police personnel, distinct from the broader Public Service Commission's remit over civil, fire, and prison services. This specialization enables targeted accountability, with powers to investigate complaints and impose penalties, though empirical audits on misconduct reductions remain limited; independent reviews in similar oversight frameworks indicate that structured disciplinary mechanisms correlate with lower internal violation rates when enforced consistently, as opposed to decentralized command structures prone to bias. Overall, these commissions prioritize causal linkages between vetted recruitment and sustained force discipline, drawing on personnel data for evidence-based decisions rather than anecdotal reforms.

Persons with Significant Control

The Persons with Significant Control (PSC) regime requires companies, partnerships, and certain other entities to identify and disclose individuals who own or exert over them, thereby enhancing in corporate to deter illicit finance such as and . Enacted through the Small Business, Enterprise and Employment Act 2015 and effective from 6 April 2016, the regime mandates maintenance of a PSC register at , publicly accessible to reveal beneficial owners hidden behind complex structures. A PSC is defined as an individual meeting one or more conditions: holding more than 25% of shares or voting rights; having the right to appoint or remove a of directors; or exercising significant or over the entity, including through trusts or indirect means. Companies must confirm PSC details annually via confirmation statements, with failure to comply constituting an offence subject to civil penalties starting at £500 and escalating for persistent non-disclosure, alongside potential criminal prosecution for knowingly providing false information. The regime's core objective is to pierce layers of corporate anonymity that enable shell company abuse, integrating with UK anti-money laundering (AML) frameworks under the Money Laundering Regulations 2017 to verify ultimate and reduce opportunities for economic crime. Post-implementation reviews indicate it has facilitated earlier detection of opaque structures used for , as the became the first nation with a public register, though enforcement relies on proactive scrutiny rather than automatic data cross-checks. Amendments via the Economic Crime and Corporate Transparency Act 2023, receiving on 10 October 2023, bolster enforcement by granting powers to demand evidence, issue compliance notices, and impose fines up to £10,000 for identity verification failures, with mandatory digital ID checks for new PSCs from March 2024 and phased rollout for existing ones by November 2025. These measures prioritize efficacy, evidenced by 2024's introduction of automated queries and strikes against non-compliant entities, over individual privacy concerns, as non-disclosure fines underscore the causal deterrent against anonymous control facilitating illicit flows.

Medicine and biology

Primary sclerosing cholangitis

(PSC) is a chronic, progressive cholestatic marked by immune-mediated , , and multifocal stricturing of intrahepatic and extrahepatic ducts, leading to flow obstruction, , biliary , and eventual hepatic decompensation. The pathologic hallmark involves periductal ("onion-skin" pattern on ), segmental involvement producing a beaded appearance on , and increased risk of , with cumulative incidence of 6-13% over 10-20 years post-diagnosis. Unlike secondary sclerosing cholangitis, PSC lacks identifiable causes such as prior or ischemia, and its involves complex interactions of genetic and immune dysregulation, though no single causal pathway is established. Epidemiologic data from population-based cohorts indicate an incidence of 0.6-1.0 per 100,000 person-years and of 6-16 per 100,000, with higher rates in Northern European-descended populations and a male predominance (male-to-female ratio 2-3:1). Age at typically peaks in the 30s-40s, though bimodal occurs; incidence has remained over decades without clear geographic or temporal trends beyond genetic ancestry. PSC confers elevated in patients with , but causality direction remains unresolved in cohort analyses. Diagnosis relies on cholangiographic demonstration of irregular, multifocal biliary strictures and dilatations via , preferred for its non-invasiveness, or when therapeutic intervention is needed or MRCP is inconclusive. Supporting features include elevated serum (often >3x upper limit of normal) and antimitochondrial antibody negativity to distinguish from ; liver biopsy is not diagnostic but may reveal fibro-obliterative lesions in atypical cases. Exclusion of mimics like immunoglobulin G4-related sclerosing cholangitis requires serum IgG4 levels and if dominant strictures suggest . Genetic factors predominate in risk profiling, with genome-wide association studies identifying (HLA) alleles—particularly HLA-B08, HLA-DR3, and HLA-DRB113—as conferring odds ratios up to 3-5 for susceptibility, reflecting T-cell mediated targeting. Non-HLA loci like and MST1 further modulate risk, supporting an inherited immune dysregulation basis over environmental triggers alone. Environmental hypotheses, including microbial translocation or xenobiotics, lack prospective validation; dietary interventions promoted in non-peer-reviewed outlets (e.g., gluten-free or low-carbohydrate regimens) derive from small pilots showing biochemical shifts but no (RCT) evidence of histologic or survival benefits, underscoring absence of causal links. No pharmacologic agent halts progression; (UDCA) at 13-15 mg/kg/day reduces serum in phase III trials but fails to improve transplant-free survival or endpoints in multicenter RCTs, with high-dose (28-30 mg/kg/day) regimens linked to increased mortality from portal complications. and norursodeoxycholic acid show promise in phase II trials for biochemical response but await confirmatory outcome data. Endoscopic management targets dominant strictures via stenting to alleviate pruritus or cholangitis, though recurrence risk persists. Liver transplantation remains the definitive therapy for decompensated or recurrent bacterial cholangitis, with (UNOS) registry data reporting 1-, 5-, and 10-year post-transplant patient survival of 97%, 89%, and 79%, respectively, superior to waitlist outcomes due to lower (MELD) progression. Recurrence of PSC in the allograft occurs in 20-30% at 5-10 years, associated with younger age and non-HLA factors, but does not significantly impair overall graft survival in large cohorts. Surveillance for via and imaging is standard, though sensitivity remains limited pre-transplant.

Phosphatidylserine

Phosphatidylserine (PS) is an anionic phospholipid component of cell membranes, particularly enriched in the plasma membrane and neuronal tissues, where it contributes to maintaining membrane fluidity and asymmetry. It plays a key role in cellular processes such as signaling cascades, where its exposure on the outer membrane leaflet acts as an "eat me" signal for phagocytic clearance of apoptotic cells and facilitates blood clotting by interacting with coagulation factors. PS also supports membrane trafficking and vesicle fusion, essential for synaptic transmission and neuronal communication. Commercially, PS is sourced primarily from soy lecithin through enzymatic processes, following a shift from bovine brain-derived PS in the due to concerns over ; the U.S. has affirmed GRAS status for soy-derived PS at levels up to 90% purity for use in foods and supplements. from randomized controlled trials indicates that oral supplementation with 400–800 mg/day of PS blunts the cortisol response to acute stressors like exercise; for instance, 800 mg of bovine cortex-derived PS reduced post-exercise cortisol by approximately 30% compared to in a 1997 study, with similar attenuating effects observed at 400 mg doses in later soy-based formulations. These effects are attributed to PS's modulation of hypothalamic-pituitary-adrenal axis activity, independent of changes in ACTH levels. In applications, PS supplementation at 100–300 mg/day has shown modest benefits for cognitive function, including improved and in children with ADHD symptoms, as evidenced by symptom reductions in small clinical trials. Meta-analyses of trials in elderly populations with age-associated cognitive decline report positive effects on domains, potentially via PS's enhancement of function, such as increasing and affinity and supporting . However, claims of substantial efficacy against lack validation from large-scale, long-term randomized trials, with early bovine PS studies showing inconsistent results in Alzheimer's patients and relying on small cohorts without robust replication. Mechanisms involving reduced and preserved provide a causal basis for observed benefits, but overhyped therapeutic assertions exceed the from available RCTs.

Military and security

President's Security Command

The (PSC) in the operates as an elite component of the Armed Forces of the (), primarily responsible for close protection, escort duties, and threat neutralization involving the , , and select dignitaries. Originally structured as a command unit during the 1970s and 1980s under to counter threats and safeguard executive continuity amid law-era instability, it emphasized integrated military operations blending VIP security with selective counter- support. Disbanded in 1986 after the , it functioned as the leaner until reinstatement as PSC on January 23, 2024, under Nelson Morales, to address contemporary risks through expanded resources and coordination. Selection for PSC service demands exceptional physical fitness, marksmanship proficiency, and psychological resilience, drawn from AFP ranks with additional vetting for loyalty and discretion. Training regimens include specialized modules such as the VIP Protection Course, covering advanced , convoy operations, and intelligence-driven perimeter , often augmented by international exchanges like those conducted in for tactical refinement. Equipment standards feature state-issued firearms, armored vehicles, and surveillance systems calibrated for urban and rural threat environments, with protocols updated to incorporate cyber and countermeasures. Official AFP evaluations highlight the unit's operational discipline, evidenced by sustained protection without successful breaches of primary principals since restructuring, reflecting a focus on empirical threat mitigation over procedural formalities. In , the analogous Presidential Security Service (PSS) functions as an autonomous agency under direct presidential authority, integrating seamlessly into the national command structure for the defense of the , , and key residences like the . Established post-Korean War to prioritize regime stability against ideological subversion, the PSS maintains a led by a vice-ministerial director, with specialized battalions for medical support, , and explosive ordnance disposal, ensuring layered redundancy in high-threat scenarios. Its efficacy stems from mandatory pipelines feeding elite personnel, rigorous annual drills simulating attempts, and statutory that bypasses inter-agency delays, as affirmed in the Presidential Security Act governing duties and armament.

Places and geography

Port Sudan (airport code)

Port Sudan New International Airport serves as the principal aviation hub for , Sudan's key Red Sea port city, facilitating operations including commercial passenger flights, linked to regional , and deliveries. Designated with IATA code PZU and ICAO code HSPN, the facility is located approximately 20 kilometers south of the city center and features a paved measuring 2,500 meters in length, supporting international connectivity primarily to destinations in the and . As Sudan's second-busiest international airport by air traffic volume and destinations served, it underpins logistical support for activities, with operations tied to the export of products via the adjacent seaport, which handles over 80% of the country's oil shipments. The airport exhibits dual civil-military characteristics, having replaced the former Port Sudan Military Airport and occasionally accommodating strategic flights amid dynamics. It has become a vital node for humanitarian operations since the escalation of internal conflicts in 2023, serving as the primary for flights delivering supplies, personnel, and relief goods to conflict-affected regions, with agencies relying on it for the bulk of inbound assistance. Disruptions from strikes in 2025 temporarily halted operations, underscoring its infrastructural centrality, yet it resumed critical functions to sustain flows estimated at thousands of tons annually. Infrastructure expansions have addressed growing demands post-2010, including the near-completion of enlarged parking aprons by mid-2024 to boost for larger freighters and increased traffic, alongside additions of a VIP and dedicated hangar in early 2025. These upgrades, driven by rising commercial and relief needs, align with Sudan's integration into trade corridors, though specific ICAO traffic data remains limited; pre-conflict estimates indicated handling several thousand passengers and substantial cargo tonnage yearly, with causal links to economic stabilization via enhanced connectivity.

Politics and activism

Palestine Solidarity Campaign

The (PSC) is a -based established in 1982 amid preparations for Israel's invasion of , later incorporated as a in 2004. It describes its mission as advancing Palestinian rights through grassroots advocacy, including challenges to government policies perceived as supportive of Israel's , promotion of corporate accountability, and media scrutiny. The group operates branches across the and collaborates with affiliated entities to organize events and efforts focused on ending what it terms Israel's "illegal ." PSC endorses the Boycott, Divestment, and Sanctions (BDS) movement, launched in 2005 by Palestinian civil society, as a non-violent strategy to pressure over policies including expansion and the blockade. It has coordinated nationwide demonstrations, notably leading or co-organizing large-scale protests following the October 7, 2023, attacks and ensuing conflict, with events drawing estimates of up to 300,000 participants in on November 11, 2023, marking one of the largest pro-Palestinian rallies in British history. These activities include calls for halting arms sales to and suspending diplomatic ties, influencing debates within affiliated bodies. Funding and support for PSC derive substantially from trade union affiliations, with major unions such as , Unite, and the among its backers, comprising seven of the ten largest TUC affiliates as of 2025. These partnerships enable coordinated campaigns, including parliamentary lobbies and resolutions within unions to adopt BDS-aligned policies, though financial on the organization's remains limited, omitting detailed donor disclosures. PSC claims policy impacts, such as shifts in public and institutional discourse toward recognizing , evidenced by growing union endorsements and protest turnout altering political rhetoric on the conflict. Critics, however, argue these efforts exhibit one-sided advocacy, sidelining Hamas's role in escalations and concerns, potentially exacerbating communal tensions without reciprocal demands on Palestinian actors. PSC has faced allegations of fostering antisemitism, particularly through event programming and affiliations, with a 2025 investigation by documenting patterns of bigotry at PSC-led demonstrations, including speakers invoking tropes and minimization since October 2023. The group rejects the ( for equating certain Israel criticisms with Jew-hatred, maintaining its campaigns target state policies rather than . Empirical data from and community reports highlight "hybrid hate" incidents—blending anti-Israel protest with antisemitic acts—at PSC events, prompting scrutiny from bodies like the () in broader inquiries into institutional responses. While PSC defends free speech in such critiques, failed or settled claims against pro-Palestinian entities, including parallels in charity cases where accusers retracted under legal pressure, underscore tensions between advocacy and reputational protections. These controversies reflect deeper debates on whether PSC's focus on Israeli accountability inadvertently amplifies prejudicial narratives, as evidenced by analyses of left-wing anti-Israel bias in correlating with rising antisemitic incidents.

Partido Social Cristiano

The Partido Social Cristiano (PSC) is a center-right political party in , established in 1951 by Camilo Ponce Enríquez as the Movimiento Social Cristiano to advance Christian democratic ideals emphasizing and opposition to . The party's platform draws from , prioritizing traditional family structures, moral values rooted in Christianity, and resistance to leftist ideologies that it views as undermining national stability and cultural heritage. Early leaders like Ponce Enríquez, a former president (1956–1960), positioned the PSC as a bulwark against communist influences during the era, fostering alliances with business interests and conservative elites. Electorally, the PSC achieved significant successes in the 1980s and early 1990s, including the presidency of León Febres Cordero from 1984 to 1988, during which the administration pursued free-market reforms such as privatization, trade liberalization, and fiscal austerity to combat hyperinflation exceeding 50% annually in the early 1980s and stabilize the economy, achieving GDP growth averaging 2.5% yearly by mid-decade despite external debt pressures. Sixto Durán Ballén, another PSC figure who ran unsuccessfully in 1979, secured the presidency in 1992, continuing pro-business policies amid ongoing economic volatility. These periods highlighted the party's commitment to market-oriented governance, though left-wing critics attributed rising inequality— with the Gini coefficient climbing to around 0.55 by the late 1980s—to neoliberal adjustments, a claim countered by data showing reduced inflation from triple digits to single digits under Febres Cordero. The PSC's platform consistently advocates for policies safeguarding units against perceived secular erosions, including opposition to expansive interventions in spheres, while promoting private enterprise and to foster over . Post-2000, the party faced electoral marginalization as voters shifted toward populist alternatives amid economic crises and the rise of Correa's , which captured power in 2007; PSC presidential candidates garnered under 13% in 2002 and similarly low shares thereafter, reflecting a broader erosion of traditional parties rather than isolated ideological rejection. This decline correlates with Correa-era reforms that centralized authority and diminished opposition influence, though the PSC retains localized strongholds in coastal regions like .

Science and technology

Postsynaptic current

A postsynaptic current (PSC) is an electrophysiological signal representing the net ionic flux across the postsynaptic membrane of a , triggered by neurotransmitter release from the presynaptic terminal and subsequent activation of ligand-gated channels. These currents are typically excitatory (EPSCs), mediated by cations such as Na⁺ and Ca²⁺ through and NMDA receptors, or inhibitory (IPSCs), driven by Cl⁻ or K⁺ via GABA_A or receptors, and are quantified under voltage-clamp conditions to isolate membrane conductance changes without confounding action potentials. In synaptic transmission research, PSCs are measured using whole-cell patch-clamp , where a micropipette forms a high-resistance seal on the , enabling precise recording of spontaneous PSCs (mPSCs)—quantal events reflecting single-vesicle releases—or evoked PSCs from controlled presynaptic . Amplitude and frequency analyses of mPSCs provide empirical quantal parameters, such as quantal size (postsynaptic sensitivity) and release probability, with recent methods improving detection reliability in slices by addressing baseline noise and event overlap. Empirical studies in hippocampal slices demonstrate PSCs' roles in (LTP) and depression (), forms of Hebbian where high-frequency stimulation (e.g., 100 Hz tetani) enhances EPSC amplitude via postsynaptic Ca²⁺ influx through NMDA receptors, triggering trafficking and for strengthened transmission, while low-frequency protocols (1-5 Hz) induce through milder Ca²⁺ signals activating phosphatases like . These mechanisms, observed consistently in juvenile to adult , rely on causal postsynaptic depolarization relieving NMDA Mg²⁺ block, with developmental shifts showing reduced LTP efficacy in mature circuits due to altered spike-timing dependence. Such data underscore specific, activity-pattern-dependent causal pathways rather than generalized malleability often exaggerated in non-empirical accounts of brain adaptability. In epilepsy research, patch-clamp recordings reveal dysregulated PSCs contributing to hyperexcitability, such as diminished IPSC amplitudes in hippocampal CA1 pyramidal neurons from models, reflecting impaired GABA_A-mediated inhibition, or enhanced EPSC/IPSC ratios in interneuron-deficient states like parvalbumin knockout mice, where failures exacerbate imbalance. Interventions targeting PSC modulation, including positive allosteric modulators restoring inhibitory currents, have shown potential in reversing presynaptic hyperexcitability in analogs. These findings from controlled slice preparations highlight verifiable ionic imbalances over speculative theories.

Power supply cabinet

A power supply cabinet serves as a protective for housing electrical distribution and control components in industrial applications, such as facilities and substations, ensuring safe containment of live parts while facilitating organized wiring and access. These cabinets typically feature robust or aluminum to internal elements from dust, moisture, and mechanical damage, with designs adhering to established standards for environmental resilience. Key safety standards include NEMA ratings, which classify s based on protection levels—such as Type 1 for indoor general purpose or Type 4X for corrosion resistance and water-tightness—and IP codes under IEC 60529, specifying ingress protection against solids and liquids, like IP65 for dust-tight and low-pressure jet resistance. These ratings mitigate risks like incidents, where OSHA reports indicate that electrical burns from arcs account for up to 80% of reported workplace electrical injuries, often linked to inadequate integrity allowing fault propagation. Empirical data from NFPA analysis reveals 5 to 10 events daily in the U.S., with proper cabinet ratings enabling arc-resistant designs that contain plasma temperatures exceeding 35,000°F and reduce incident energy exposure. Internally, cabinets commonly integrate components like molded-case circuit breakers for protection, distribution transformers for voltage stepping, and busbars for efficient power routing, all mounted on insulated supports to prevent short circuits. In , such as data centers or hospitals, causal design principles incorporate redundancy, including dual feeder circuits and breaker configurations, to maintain continuity during component failures, as evidenced by Uptime guidelines emphasizing concurrent to achieve 99.982% uptime. systems and grounding provisions further enhance reliability by dissipating heat and diverting fault currents, directly addressing failure modes observed in OSHA incident logs where breaches contributed to 10% of arc-flash fatalities from 2011-2021.

Sports and education

PSC (sports clubs)

The acronym PSC designates several amateur and regional sports clubs, predominantly in youth soccer, which emphasize player development, local league participation, and community engagement over professional competition. The Parsippany Soccer Club (PSC), located in Parsippany, New Jersey, serves players from under-8 (U8) to U19 levels through academy, premier, and travel programs. Its teams compete in structured leagues including the U.S. Youth Soccer Elite 64 National League and National Premier Soccer League (NPSL) divisions. PSC earned designation as a Players First-licensed club by U.S. Youth Soccer, recognizing standards in coaching, player development, and facilities. In December 2012, the club's U-17 Gators team clinched the Super Y-League national championship, defeating Ironbound Soccer Club 4-2 in extra time. The Pasadena Soccer Club (PSC), based in , provides recreational, elite, and travel soccer for , prioritizing skill-building and lifelong participation in local and regional tournaments. From 2014 to 2016, its 10U United squad recorded 67 wins, 13 losses, and 8 draws while securing seven tournament victories. The club maintains fields and programs aligned with developmental leagues, such as those under regional youth soccer associations. Additional PSC entities include the Pacific Soccer Club in , a nonprofit recreational program for U5 to U19 players focused on affordable community-based play without elite competitive mandates. The Peninsula Sports Club (PSC), established in 1949 on Virginia's Peninsula, operates as a booster organization honoring high school, college, and professional athletes across multiple sports via scholarships and events, rather than direct team fielding. These clubs exemplify PSC's use in contexts, with records grounded in tournament outcomes and league affiliations rather than broader narratives.

Philippine Science High School (or similar educational)

The (PSHS) operates a network of specialized secondary schools across the , targeting intellectually gifted students with aptitude in science and . Established under Republic Act No. 3661, signed on June 22, 1963, the system formally commenced operations on September 5, 1964, with the main campus in . It admits scholars via the Competitive , selecting top performers from and elementary schools nationwide, with scholarships covering tuition, board, and allowances contingent on maintaining academic standards and pursuing degrees in college. The PSHS curriculum spans six years (grades 7-12), prioritizing intensive instruction in , physics, chemistry, , and research methodologies, alongside humanities and to foster well-rounded development. This structure emphasizes hands-on experimentation, problem-solving, and evidence-based inquiry, producing graduates who demonstrate strong empirical outcomes: alumni data indicate high enrollment in top programs at institutions like the and abroad, with many advancing to roles in , , and . For instance, PSHS scholars have secured positions at prestigious bodies such as MIT's Kavli Institute, underscoring the system's track record in cultivating verifiable expertise over broader curricular dilutions. As of 2025, the system comprises 16 campuses serving over 8,000 scholars, supported by recent legislation like Republic Act No. 12310, which expands infrastructure and mandates consistent -focused quality to address national shortages in scientific personnel. While some deviate from STEM paths, aggregate placement metrics affirm the program's causal efficacy in elevating participants' contributions to Philippine , with minimal integration of non-empirical educational trends that prioritize .

Transport and infrastructure

Tri-Cities Airport (PSC code)

Tri-Cities Airport, designated by the IATA code PSC and ICAO code KPSC, is a public-use commercial service airport owned and operated by the of Pasco, located approximately two miles northwest of downtown . It serves the metropolitan area, encompassing Pasco, Kennewick, and Richland in Franklin and Benton counties, facilitating regional , cargo operations tied to the area's agricultural (including wine production and farming), and general aviation. The airport supports nonstop commercial flights to major hubs such as , , , , and via carriers including , , and . Established on the site of the former Franklin County Airport, PSC originated in 1942 as a U.S. Navy training facility during , with commercial passenger service commencing in the postwar era following initial operations dating back to 1926 under Varney Airlines (predecessor to ). Infrastructure developments include two asphalt runways: the primary 03L/21R measuring 10,000 by 150 feet, capable of handling larger jets, and a secondary 03R/21L at 5,000 by 75 feet; these support instrument approaches and have undergone extensions and upgrades, notably a $43 million terminal and apron expansion completed in 2017 to accommodate growing demand. Such enhancements have directly enabled expanded service to economic drivers like the nuclear reservation and freight, contributing to the airport's role in regional connectivity without reliance on broader policy subsidies. Passenger traffic at PSC has shown consistent growth since the , driven by expansions and proximity to Washington's southeast agricultural and tech corridors, with enplanements reaching 476,639 in calendar year 2024 per records. Total travelers hit a record 949,110 in 2024, surpassing the prior year's 872,578 and reflecting an 8.8% enplanement increase, with monthly peaks like 2025's 49,014 exceeding prior benchmarks. The airport sustains approximately 2,194 direct jobs and bolsters freight for perishable goods, underscoring its operational efficiency with load factors around 85%, above the national average.

Other uses

PSC (musical group)

Pimp Squad Click (stylized as P$C), a collective from Atlanta's Bankhead neighborhood, formed in 2001 under the leadership of rapper (Clifford Harris Jr.) alongside his longtime associates, reflecting the gritty street dynamics of early-2000s Atlanta . The group, originally comprising , , C-Rod ( Thomas), AK (Akeem Lawal), and Mac Boney, drew from local hustling culture, with AK later departing and occasionally affiliating through shared ties. Their output emphasized raw narratives of pimping, , and survival, aligning with the Southern rap wave that elevated Atlanta's profile via independent mixtape circuits before major-label breakthroughs. The collective's early discography centered on self-released mixtapes under the In da Streetz series, distributed through Atlanta's underground networks in the early to build regional buzz and foster T.I.'s Grand Hustle empire. These tapes, featuring unpolished tracks on street economics and rivalries, preceded their sole major-label studio album, , released September 20, 2005, via Grand Hustle and . The album's title alluded to the approximate ages of core members at formation, peaking at No. 10 on the chart upon debut amid a competitive fall release slate, though it garnered lukewarm critical reception for formulaic tropes. Singles like "I'm a King" (featuring and ) highlighted posse-cut energy but failed to sustain commercial momentum, underscoring PSC's role as a crew extension rather than standalone chart dominators. Culturally, PSC amplified Atlanta's blueprint—characterized by 808-heavy beats and autobiographical crime tales—through 's mentorship, influencing mid-2000s Southern collectives by normalizing crew-based hustles that bypassed traditional radio gatekeepers. However, their lyrics, steeped in glorification of and pimping as economic imperatives, mirrored broader Southern critiques; while some studies correlate exposure to such content with attitudinal shifts toward aggression in youth demographics, causal evidence tying specific acts like PSC to real-world crime spikes remains empirically weak and confounded by socioeconomic factors. The group avoided high-profile feuds as a unit, though 's individual beefs, such as with , indirectly colored their narrative of territorial authenticity without escalating to PSC-branded diss tracks. Post-, activity waned amid 's solo ascent, positioning PSC as a foundational but niche artifact in trap's commercialization.

Programmable security code

The programmable security code (PSC) is a hardware-enforced mechanism integrated into certain chips, such as the SLE 4428 and SLE 4442 series, to restrict write and erase operations on the data memory. This feature requires verification of a multi-byte code—typically 2 or 3 bytes—stored separately in a memory area before any modification to the user data is permitted, while read remains unrestricted. The PSC is programmable during initialization but designed for one-time or limited reconfiguration to enhance tamper resistance. Verification involves transmitting the PSC via the chip's two-wire serial interface compliant with ISO 7816 standards, triggering a comparison against the stored value. A 3-bit error counter accompanies the mechanism; after eight consecutive incorrect attempts, it locks out further verifications, preventing brute-force attacks and requiring a hardware reset or specialized erasure procedure to restore functionality. This counter operates independently of the data memory, ensuring persistent enforcement even after power cycles. Chips like the SLE 5542 extend this with 256 bytes of protected , optimizing layout for security in technology. In practice, PSC-equipped cards find application in low-to-medium security scenarios, including key cards, hotel room locks, and basic tokens, where prevention of unauthorized data alteration suffices without needing . For instance, the FM 4428 variant supports 1024 x 8-bit with PSC logic, enabling secure storage in systems like electronic door entry. Empirical evaluations of similar schemes indicate reduced incidence of casual tampering in deployed systems, though vulnerabilities persist if the PSC is compromised through physical attacks or supply-chain leaks, underscoring the need for complementary measures like secure provisioning. Adoption remains steady in legacy and cost-sensitive deployments as of 2023, with no documented widespread breaches attributed solely to PSC failures in peer-reviewed analyses.