All articles A–Z

Stability study statistics

Stability study statistics is the branch of pharmaceutical statistics that designs drug stability protocols and estimates shelf life, chiefly by regressing a quality attribute against time under ICH Q1E guidance.

Stability theory

Stability theory is the branch of model theory, founded on Saharon Shelah's classification program, that sorts first-order theories into dividing lines such as stable, simple, and NIP.

STABILITY trial (NCT00799903)

STABILITY (NCT00799903), Stabilization of Atherosclerotic Plaque by Initiation of Darapladib Therapy: phase 3 GlaxoSmithKline trial of darapladib 160 mg daily in 15,828 stable coronary heart disease patients; Lp-PLA2 lowered ~65% but primary endpoint (cardiovascular death, MI, stroke) not reduced (HR 0.94).

Stability-indicating method

A stability-indicating method, also called a stability-indicating assay, is a validated analytical procedure, typically HPLC with UV detection, that quantifies a drug's active ingredient without interference from degradation products, impurities, or excipients.

Stabilizer (aeronautics)

A stabilizer in aeronautics is a fixed tail surface of a fixed-wing aircraft: the horizontal stabilizer gives pitch stability, and the vertical fin gives yaw stability.

Stabilizer formalism

The stabilizer formalism, introduced by Daniel Gottesman in 1997, describes quantum states by the Pauli operators that fix them, enabling efficient classical simulation of Clifford circuits.

Stabilizer subgroup

The stabilizer subgroup, also called the isotropy group or little group, consists of the elements of a group action that leave a given point fixed.

Stabilometry

Stabilometry is a clinical assessment method that quantifies postural sway in standing subjects with a force platform, used in evaluating vestibular deficit and fall risk.

Stable

Стайня (Polish stajnia, stable): a building for housing horses and hoofed animals, from private equestrian stables like Stajnia Mortęgi to zoo stables in Warsaw, Żywiec, and Lubin.

Stable angina

Stable angina (angina pectoris) is predictable chest pain from heart-muscle oxygen shortage, usually coronary artery disease, triggered by exertion or stress, relieved by rest or nitroglycerin, and treated with beta blockers, calcium channel blockers, and prevention drugs.

Stable Audio

Stable Audio is a family of text-to-music and text-to-audio generative models from Stability AI, first released in September 2023 and named a TIME Best Invention of 2023.

Stable belt

Stable belt: a wide, regimentally coloured cloth belt worn with British and Commonwealth barrack or working dress. Originated with Victorian cavalry stable work from the surcingle; striped in regimental tie colours, twin-strap buckle, largely private purchase.

Stable Block (30 Yards South of Wherwell Priory)

Grade I listed mid-13th-century abbey building, probably Wherwell Abbey's refectory, in Wherwell, Hampshire; list entry 1093391, first listed 1984, likely built under Abbess Euphemia.

Stable Cascade

Stable Cascade is a text-to-image diffusion model released by Stability AI in research preview in 2024, built on the Würstchen architecture and organized as three models.

Stable Diffusion

Stable Diffusion is a family of open-weight text-to-image diffusion models developed by Stability AI, first publicly released in August 2022 and since expanded through versions 1.5, 2.x, XL, and 3.5.

Stable Diffusion 1.5

Stable Diffusion 1.5 is an open-weight text-to-image diffusion model released in October 2022, small enough to run on consumer GPUs and the foundation of the open fine-tuning ecosystem.

Stable Diffusion 3

Stable Diffusion 3 is a family of text-to-image models released by Stability AI in 2024, using a Multimodal Diffusion Transformer architecture that replaced the U-Net of earlier versions.

Stable Diffusion XL

Stable Diffusion XL (SDXL) is an open-weight, diffusion-based text-to-image model released by Stability AI on July 26, 2023, with a 2.6-billion-parameter UNet and native 1024×1024 generation.

Stable distribution

The stable distribution, or Lévy alpha-stable distribution, is a probability distribution whose shape is preserved under addition; it includes the normal, Cauchy, and Lévy distributions as closed-form cases.

Stable group

A stable group is a group definable in a model of a stable first-order theory; examples include abelian groups, algebraic groups over algebraically closed fields, and free groups.

Stable isotope analysis

Stable isotope analysis (SIA) measures heavy-to-light isotope ratios of elements such as carbon, nitrogen, and hydrogen to trace where materials come from and how energy moves through ecosystems.

Stable isotope labeling

Stable isotope labeling incorporates non-radioactive heavy isotopes such as ²H, ¹³C, and ¹⁵N into biomolecules, cells, or organisms to trace metabolic pathways and fluxes by mass spectrometry or NMR.

Stable isotope labeling by amino acids in cell culture

Stable isotope labeling by amino acids in cell culture (SILAC) is a metabolic labeling method for quantitative proteomics, reported by Shao-En Ong and colleagues in 2002.

Stable Lévy process

Stable Lévy process is a continuous-time Lévy process characterized by $\alpha$-stable increments for $0 < \alpha \leq 2$. It generalizes Brownian motion and exhibits power-law-tailed increments.

Stable manifold theorem

The stable manifold theorem, also known as the Hadamard–Perron theorem, states that orbits near a hyperbolic equilibrium that approach it form a smooth manifold tangent to the stable eigenspace.

Stable matching problem

The stable matching problem, also called the stable marriage problem, asks how to pair two sets of participants so no two would both prefer each other over their assigned partners.

Stable matrix

A stable matrix, also called a Hurwitz matrix, is a square matrix whose eigenvalues all have strictly negative real parts, meaning a continuous linear system governed by it decays to zero.

Stable rank

Stable rank, or topological stable rank, is a numerical invariant of a C-algebra, introduced by Marc Rieffel in 1983 as the first noncommutative generalization of covering dimension.

Stable Ronaldo

Stable Ronaldo (Rani Netz, born 2003) is an American Twitch streamer and former Fortnite pro; 2019 FNCS champion, viral 'Payphone' clip, FaZe Clan member 2022-2025, CORE co-founder 2026.