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A buffer solution used as a running medium in DNA gel electrophoresis; it maintains pH while allowing electric current through the apparatus.

Phosphate-buffered saline is an aqueous salt solution containing phosphate species that act as a buffer solution, together with salts that control its ionic strength and osmotic properties. Common formulations are designed to maintain a near-neutral pH, but their precise composition varies.

The phosphate acid-base pair consumes added acid or base, limiting small pH shifts. The salt content makes the solution useful when biological samples need a controlled ionic environment. It does not reproduce every component of a physiological fluid, and added divalent ions can interact with phosphate; the formulation must therefore be specified when comparing experiments.

Cited passages: Thread-Safety; Overwrite Operation; Writing to a Full Buffer; Iterator Invalidation; Caveats. The documented overwrite-by-assignment and synchronization behavior belongs to Boost.Circular Buffer.

Transverse relaxation describes loss of ensemble transverse magnetization. It must not automatically be identified with pure dephasing. In a simple completely positive two-level relaxation model,where $T_{\varphi }$ describes additional pure dephasing. Thus population recovery itself contributes to transverse decay. A spread of static magnetic fields can further cancel ensemble phases without the same microscopic relaxation; an observed free signal may have an effective $T_2^{\ast }$ rather than homogeneous $T_2$. The simple exponential examples below assume a uniform field and a single homogeneous $T_2$.

With no transverse drive, the Bloch equations giveLongitudinal nuclear spin relaxation restores the population imbalance and thus the magnetization parallel to the static magnetic field. It corresponds to population relaxation for the two-level model. Starting from $M_z(0)=0$, waiting $T_1$ recovers $1-e^{-1}$ of $M_0$, whereas waiting $5T_1$ recovers about $99.3\%$. This is why repeated measurements require a recovery-time decision.

Online text: openstax.org/books/biology-2e/pages/10-1-cell-division

Section of Biology 2e by Mary Ann Clark and others, whose whole-book authors are Mary Ann Clark, Matthew Douglas and Jung Choi. OpenStax publishes the book; no separate section author is credited. The citation panel gives whole-book publication on 28 March 2018, rather than a section revision date.

Cited passages: §10.1, Genomic DNA; Eukaryotic Chromosomal Structure and Compaction, Figure 10.4 and final paragraph; citation information identifying the authors and publication date.

Section of Biology 2e by Mary Ann Clark and others. Whole-book authors: Mary Ann Clark, Matthew Douglas and Jung Choi; no separate section byline is established. OpenStax publishes and hosts the text. The book was published on 28 March 2018; no separate section revision date is established.

Online text: openstax.org/books/biology-2e/pages/8-1-overview-of-photosynthesis

Inspected locators: Basic Photosynthetic Structures, Figure 8.6; The Two Parts of Photosynthesis, Figure 8.7; citation information.

By William Hayward Pickering, credited as William H. Pickering. Memoir pp. 24–38; institutional issuer: National Academy of Sciences.

In the aqueous model here, a strong base supplies hydroxide essentially completely under the conditions considered. Strength and concentration are different properties.

A small single-stranded-DNA bacteriophage used in molecular-genetics research. Its compact genome made it useful for testing relationships among sequence, genetic organization and viral function.