All articles starting with R

Respiratory tract epithelial cell

Respiratory tract epithelial cell (airway epithelial cell, CL:0002368), an endoderm-derived epithelial cell lining the airways; ciliated pseudostratified columnar in conducting airways, with goblet, basal, ionocyte, and alveolar pneumocyte subtypes.

Respiratory tract infection

Respiratory tract infection (RTI): infection of the sinuses, throat, airways, or lungs, divided into upper and lower RTIs. Mostly viral (flu, COVID-19, RSV, common cold); most resolve in 1-2 weeks; antibiotics only for bacterial causes like pneumonia.

Respiratory tuberculosis, not confirmed

Respiratory tuberculosis, not confirmed (ICD-11 1B10.1; ICD-10 A16) is the WHO classification category for respiratory TB presumed on clinical or radiological evidence without bacteriological or histological confirmation, equivalent to clinically diagnosed TB.

Respiratory-Gated Imaging Techniques

Respiratory-gated imaging techniques, also called gated imaging techniques, respiratory, time medical image acquisition to points in the breathing cycle to reduce motion blur in MRI, CT, and PET, and coordinate radiation beam on/off cycles in gated radiotherapy.

Respirometry

Respirometry is a measurement technique that quantifies how fast an organism, tissue, or cell consumes oxygen to estimate metabolic rate, making it a form of indirect calorimetry.

Respirovirus muris

Respirovirus muris (Sendai virus, murine parainfluenza virus 1) is an ICTV-accepted species of negative-sense ssRNA virus in Paramyxoviridae, genus Respirovirus; a mouse respiratory pathogen and widely used cytoplasmic RNA gene-delivery vector.

Respite care

Respite care (temporary relief care for family caregivers; lifespan respite) is planned or emergency short-term care for people with special needs, dementia, or disabilities, lasting hours to weeks; only 14% of US caregivers receive it, funded via Medicaid waivers, Medicare hospice/GUIDE, and VA programs.

Resplendent quetzal

Resplendent quetzal (Pharomachrus mocinno), a trogon of Mesoamerican cloud forests from southern Mexico to western Panama, national bird of Guatemala, Near Threatened, feeding mainly on Lauraceae fruits and dispersing their seeds.

Response amplitude operator

A response amplitude operator (RAO) is a frequency-dependent transfer function giving the motion or load response of a ship or floating structure to a wave of unit amplitude, as a function of wave frequency.

Response bias

Response bias, also called response set, is the systematic deviation of survey answers from the true value being measured, arising from the questionnaire, the interview mode, the interviewer, and the respondent.

Response element

Response element: short DNA sequence (hormone response element, HRE, CRE, TRE, ARE) bound by transcription factors or nuclear receptors to regulate gene transcription; defined by AGAACA/AGGTCA hexamer motifs and dimer binding.

Response Evaluation Criteria in Solid Tumors

The Response Evaluation Criteria in Solid Tumors (RECIST) are standardized rules for measuring solid tumors on CT and MRI and classifying treatment response, introduced in 2000.

Response history analysis

Response history analysis (RHA), also called time-history analysis, computes the time-dependent seismic response of a structure by numerically integrating its equations of motion under an earthquake ground-motion record.

Response modification factor

The response modification factor (R) is a seismic engineering coefficient that reduces elastic design forces for a structure's ductility, overstrength, and redundancy, first codified in the ATC-3-06 report of 1978.

Response priming

Response priming is a cognitive psychology paradigm in which a brief masked prime speeds or biases a speeded choice response, studied to probe unconscious control of action.

Response spectrum

A response spectrum is a plot of the maximum acceleration, velocity, or displacement of damped oscillators excited by an earthquake, and underlies every modern seismic design code.

Response spectrum analysis

Response spectrum analysis, also called the response spectrum method, is a structural dynamics method that estimates a structure's peak seismic response by combining modal responses from an earthquake response spectrum.

Response surface design

A response surface design is a design of experiments method that fits a quadratic model to input variables and responses, so a process can be optimized.

Response surface methodology

Response surface methodology (RSM), also called the Box-Wilson method, is a collection of statistical techniques for designing experiments and optimizing process responses, introduced by Box and Wilson in 1951.

Response time (metrology)

Response time, in metrology, is the interval between an abrupt stimulus change and the moment a measuring instrument's response settles within specified limits of its final value.

Response time analysis

Response time analysis (RTA) is a schedulability analysis method for real-time systems that computes each task's worst-case response time, introduced by Joseph and Pandya in 1986.

Response to intervention

Response to intervention (RTI) is an educational framework integrating assessment with instruction in a schoolwide, multi-tiered prevention system, used for early academic support and learning disability identification.

Response-adaptive randomization

Response-adaptive randomization is a clinical trial design in which the probabilities for assigning each new patient change as outcome data accumulate, shifting allocation toward treatments performing better.

Oct 22, 2026

Responsibilities

Responsibilities is a poetry collection by William Butler Yeats, first published in 1914 and expanded in 1916, marking his turn from romanticism toward a combative public voice and containing "September 1913" and "A Coat".

Oct 10, 2026

Responsibility accounting

Responsibility accounting is an accounting system that evaluates managers on the revenues and expenses they control, dividing a firm into cost, profit, and investment centers.

Responsibility assignment matrix

A responsibility assignment matrix (RAM), best known as the RACI chart, is a project management table crossing tasks with roles and labeling each cell Responsible, Accountable, Consulted, or Informed.

Responsibility for the Holocaust

Responsibility for the Holocaust covers the Nazi leadership, SS under Himmler, Wehrmacht, German state and industry, and ordinary perpetrators like Police Battalion 101, plus postwar accountability from the Nuremberg IMT and Eichmann trial to German reparations.

Responsibility for the September 11 attacks

Responsibility for the September 11 attacks lies with al Qaeda under Osama bin Laden, with Khalid Sheikh Mohammed as planning chief. Key facts: 19 al Qaeda hijackers, $400,000-$500,000 cost, no confirmed foreign-government funding, contested Saudi support claims.

Responsibility to protect

Responsibility to protect (R2P): UN norm adopted unanimously at the 2005 World Summit covering genocide, war crimes, ethnic cleansing and crimes against humanity; three pillars; first military use in Libya 2011 (Resolution 1973), while Syria exposed selectivity and veto paralysis.