Inhalation is the inward movement of respiratory gas into the lungs. During ordinary spontaneous breathing, contraction of the respiratory diaphragm and contribution from external intercostal muscles expand the thoracic space; the resulting pressure relationships permit inward flow.^[ref] Positive-pressure ventilation can instead assist inward flow by raising pressure at the airway opening.

The flow-driving difference is between airway-opening pressure and alveolar pressure. In a simple resistive model,where $R$ is airway resistance. For constructed gauge pressures $p_{\mathrm{opening}}=0$ and $p_{\mathrm{alv}}=-2$ cm H${}_2$O, with $R=4$ cm H${}_2$O·s/L, inward flow is 0.5 L/s. These are illustrative pressures, not a measurement or a prescribed breathing pattern.

Transpulmonary pressure answers a separate question:with $p_{\mathrm{pl}}$ the pleural pressure. If the same example has $p_{\mathrm{pl}}=-7$ cm H${}_2$O, the distending difference is 5 cm H${}_2$O. At a later no-flow instant, $p_{\mathrm{alv}}$ can equal atmospheric pressure while $p_{\mathrm{pl}}$ remains negative. The expanded lung can then have positive transpulmonary pressure without continued inward airflow.

It is consequently misleading to use any single negative intrathoracic pressure as a synonym for inspiration. Pleural pressure, alveolar pressure, the applied airway pressure and volumetric flow rate refer to different parts of the mechanical system. Inhalation names the flow phase; the relevant pressure differences explain how it is produced.

Anatomical dead space is the volume of the conducting airways that transports gas without providing the pulmonary alveolus surface for gas exchange. It includes passages such as the trachea and bronchi. It is one component of respiratory dead space, distinct from alveolar dead space associated with ineffective exchange in ventilated alveolar regions.^[ref]

A single-breath tracer experiment makes the conducting volume observable. Following an oxygen inspiration, expired gas initially contains little nitrogen, then passes through a transition as airway and alveolar gas mix, and finally approaches an alveolar plateau. Recording gas fraction against expired volume distinguishes those phases.^[ref] A 1954 primary study explicitly compared single-breath measurements using different gases.^[ref]

An original idealized calculation uses expired volume $V_E$ and a normalized tracer fraction $g(V)$ that rises from zero to an alveolar value of one. Replacing a gradual transition with an equal-area step givesSuppose $V_E=0.50$ L, $g=0$ over the first 0.10 L, rises linearly to one over the next 0.10 L, and remains one for the last 0.30 L. The integral is $0.05+0.30=0.35$ L, giving $V_D=0.15$ L. Simply taking the first detectable tracer at 0.10 L would discard the mixing transition.

This is an operational estimate from a gas-transport record, not a direct anatomical scan. Mixing, the selected reference plateau and apparatus volume affect the interpretation. Identifying that measurement convention prevents a tracer-defined boundary from being mistaken for a sharp physical partition in every breath.

Exhalation is the outward movement of gas from the lungs through the airways. During ordinary quiet breathing, relaxation after inhalation allows elastic recoil to reduce lung volume. Forceful expiration can additionally involve active muscles.^[ref] The term identifies a flow phase, rather than one universal muscle-activation pattern.

For an ideal passive compartment, let $V$ be the excess volume above equilibrium with the outlet pressure. With airway resistance $R$ and respiratory-system compliance $C$,An original example uses $R=10$ cm H${}_2$O·s/L, $C=0.06$ L/cm H${}_2$O and $V_0=0.60$ L. The time constant is 0.60 s, leaving about 0.221 L excess volume after one time constant. After three time constants, only about 0.030 L remains. These are model calculations, not recommended expiration times.

The flow-driving pressure difference is between alveolar pressure and the pressure at the open airway. Pleural pressure affects the distension and geometry of the lung and airway but is not interchangeable with either of those endpoint pressures. Active expiration can also narrow intrathoracic airways, so greater effort need not produce proportionally greater flow.^[ref]

The linear decay model is therefore useful for isolating resistance, compliance and available time, while measured flow can reflect changing airway geometry, active effort or multiple compartments. Completing one expiratory interval is a mechanical event; removing a given amount of carbon dioxide additionally depends on the composition and origin of the expired gas.

Public Health Reports 30(46), 12 November 1915, pp.3336–3339 (PDF pages 2–5). Printed pp.3337–3339: diet, controls, six or more cases among eleven volunteers, conclusion. Original publication, not the 1990 reprint.

Official template: cdn.who.int/media/docs/default-source/documents/epp/respiratory-unity-study/unity-studies_g2_hhti.pdf

Section 1.3, printed p. 8, defines the latent period from infection to infectiousness and the incubation period from infection to clinical symptoms; Figure 1 distinguishes these intervals.

Verified Lesson 1, section 11, Level of disease and Epidemic Patterns: baseline-relative epidemic definition, case curves and common-source versus propagated patterns. The wiki numerical baseline example and SIR calculation are independent illustrations. Institutional source; follows existing CDC cards without a personal-author tag.

A psychological construct is a theoretically specified attribute or process used to explain behavior and experience. Working memory, for example, is not directly observed as a number on an instrument; researchers infer aspects of it from performance under stated tasks. A psychological construct supplies an interpretation of observations, rather than merely renaming a test score.^[ref]

Different operational definitions can target the same proposed attribute. Their agreement, differences and relationships to other measures inform construct validity. If a memory task also requires reading, a low score might reflect reading difficulty as well as the intended memory demand. Clear theory and several complementary measurements help distinguish these explanations.

By Amos Tversky and Daniel Kahneman. Science211(4481),453–458(30January1981). DOI doi.org/10.1126/science.7455683

Original publisher abstract: preference reversals under alternative formulations of equivalent decision problems, including monetary outcomes. Numerical choices written in the article are original teaching examples, not asserted original study conditions.

By Saul Sternberg. Science153(3736),652–654(5August1966). DOI doi.org/10.1126/science.153.3736.652

Original-paper copy www.ucg.ac.me/skladiste/blog_10209/objava_71030/fajlovi/Sternberg.pdf verifies full author byline. Abstract: mean reaction time increases with memorized-set length; original serial-comparison interpretation. An illustrative linear model does not uniquely prove that architecture.

By George Sperling. Psychological Monographs: General and Applied 74(11, Whole No.498), 1–29 (1960). DOI doi.org/10.1037/h0093759

Original author-hosted paper sites.socsci.uci.edu/~whipl/staff/sperling/PDFs/Sperling_PsychMonogr_1960.pdf

Introduction, p.1: reporting what is seen confounds available information with report limits. Partial-report experiments3–5; Experiment7, p.16: high/low tones select report order at specified post-exposure delays. Method details verified against indexed original text; invented examples are not reported data.

By William D. Marslen-Wilson and Alan Welsh. Cognitive Psychology 10(1), 29–63 (January 1978). DOI doi.org/10.1016/0010-0285(78)90018-X

Abstract: shadowing and mispronunciation-detection tasks; syllable-position and contextual-constraint effects, and a cohort account of continuous spoken-word recognition.

By Natalie Sebanz and colleagues. Cognition 88(3), B11–B21 (July 2003); DOI doi.org/10.1016/S0010-0277(03)00043-X

Author-institution record: research.birmingham.ac.uk/en/publications/representing-others-actions-just-like-ones-own/

Abstract: distribute the two responses of a spatial compatibility task between two people; compare solitary and joint performance, and a single person performing both responses. A compatibility effect occurred in the joint setting.

Brian Nosek, 28 November 2023. Author retrospective: founding of COS with Jeff Spies in 2013; transfer of OSF and Reproducibility Project: Psychology; four-laboratory prospective replication design.

Full title: The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information. Psychological Review 63, 81–97.

Relevant passages: immediate memory, recoding, and concluding comparison with absolute judgment.

Primary 1904 paper in institutional transcription; original publication American Journal of Psychology 15, 201–293. Original publication record.

GORT-5 Test structure: Rate, Accuracy, Fluency, Comprehension and Oral Reading Index. No protected test items reproduced.

Seventh edition publisher description: graded words and passages, accuracy, rate and oral/silent comprehension. Publisher preface.

Publisher description of Passage Comprehension: using syntactic and semantic context to supply a missing word.