Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Nonlinear Pharmacokinetics: Causes of Nonlinearity01:22

Nonlinear Pharmacokinetics: Causes of Nonlinearity

821
Nonlinearity in drug pharmacokinetics is caused by various factors influencing how a drug is absorbed, distributed, metabolized, and excreted. Understanding these nonlinear processes is crucial for predicting drug behavior in the body and optimizing drug dosing regimens.
Nonlinear drug absorption can occur when the process is rate-limited by solubility, carrier-mediated transport systems, or saturation of the presystemic gut wall or hepatic metabolism. For instance, high doses of riboflavin...
821
Introduction to Nonlinear Inequalities01:25

Introduction to Nonlinear Inequalities

261
Linear and nonlinear inequalities are fundamental for analyzing variable relationships and identifying ranges satisfying specific conditions. A linear inequality involves variables raised only to the first power, resulting in a straight-line graph. This line partitions the coordinate plane into two distinct regions: one that satisfies the inequality and one that does not. Each region represents a set of solutions where the linear relationship holds true under the specified constraint.Nonlinear...
261
Nonlinear Pharmacokinetics: Overview01:19

Nonlinear Pharmacokinetics: Overview

1.3K
Nonlinear or dose-dependent pharmacokinetics is a phenomenon that occurs when the pharmacokinetic parameters of certain drugs deviate from linear pharmacokinetics at higher doses. These drugs do not follow the expected first-order kinetics, where the rate of drug elimination is directly proportional to the drug concentration. Instead, they exhibit a nonlinear relationship, which can be attributed to several factors.
Nonlinearity can arise due to the saturation of plasma protein-binding or...
1.3K
Parameters Affecting Nonlinear Elimination: Zero-Order Input, First-Order Absorption and Two-Compartment Model01:13

Parameters Affecting Nonlinear Elimination: Zero-Order Input, First-Order Absorption and Two-Compartment Model

377
Drugs administered through various routes can lead to nonlinear elimination, resulting in complex pharmacokinetic behaviors crucial to understanding efficacious drug dosing.
When a drug is administered through a constant intravenous infusion and eliminated via nonlinear pharmacokinetics, it follows zero-order input. For example, oral drugs undergo first-order absorption upon administration and are eliminated through nonlinear pharmacokinetics.
In the case of subcutaneously administered drugs,...
377
Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving01:29

Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving

376
Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations.
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
376
Application of Nonlinear Inequalities01:29

Application of Nonlinear Inequalities

285
A nonlinear inequality describes a comparison involving an expression that curves or behaves more complexly than a straight line. These inequalities often appear in forms that include squares, products, or variables in the denominator.To solve such an inequality, one starts by rewriting it so that zero appears on one side. For example, the inequality:  can be factored as: This form makes it easier to identify the values that cause the expression to equal zero. In this case, the...
285

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Ethical Challenges in the Delivery of Family-Centered Nursing Care.

Journal of family nursing·2026
Same author

Moving Family Ethics Forward.

Journal of family nursing·2026
Same author

Implementing a behavioural intervention for paediatric type 1 diabetes: Key informant perspectives of multilevel barriers and facilitators.

Diabetic medicine : a journal of the British Diabetic Association·2026
Same author

The standing faculty Clinician Educator role in nursing: Benefits and challenges.

Nursing outlook·2026
Same author

A Cluster Analysis of Clinician Distress Trajectories when Caring for Seriously Ill Hospitalized Patients.

Journal of palliative medicine·2026
Same author

A comparative effectiveness trial for universal psychosocial screening with the Psychosocial Assessment Tool (PAT) across 18 childhood cancer programs in the United States: adoption, penetration, and health equity.

Implementation science : IS·2026

Related Experiment Video

Updated: Mar 6, 2026

Problem-Solving Before Instruction PS-I: A Protocol for Assessment and Intervention in Students with Different Abilities
10:26

Problem-Solving Before Instruction PS-I: A Protocol for Assessment and Intervention in Students with Different Abilities

Published on: September 11, 2021

4.5K

Incorporating nonlinearity into mediation analyses.

George J Knafl1, Kathleen A Knafl2, Margaret Grey3

  • 1School of Nursing, University of North Carolina at Chapel Hill, 5014 Carrington Hall, Campus Box 7460, Chapel Hill, NC, 27599-7460, USA. gknafl@unc.edu.

BMC Medical Research Methodology
|March 22, 2017
PubMed
Summary
This summary is machine-generated.

New adaptive regression methods effectively model nonlinear mediation relationships, crucial for understanding complex interactions in behavioral and medical sciences. These techniques account for monotonic pathways, enhancing accuracy in mediation analysis.

Keywords:
Adaptive regressionChildhood chronic conditionsFractional polynomialsMediationModerated mediationNonlinearity

More Related Videos

Applying an eMASS Customization Program as a Research Tool to Evaluate Consumer Benefits
08:27

Applying an eMASS Customization Program as a Research Tool to Evaluate Consumer Benefits

Published on: September 27, 2019

7.3K
Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
04:35

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

Published on: July 3, 2020

3.8K

Related Experiment Videos

Last Updated: Mar 6, 2026

Problem-Solving Before Instruction PS-I: A Protocol for Assessment and Intervention in Students with Different Abilities
10:26

Problem-Solving Before Instruction PS-I: A Protocol for Assessment and Intervention in Students with Different Abilities

Published on: September 11, 2021

4.5K
Applying an eMASS Customization Program as a Research Tool to Evaluate Consumer Benefits
08:27

Applying an eMASS Customization Program as a Research Tool to Evaluate Consumer Benefits

Published on: September 27, 2019

7.3K
Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
04:35

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

Published on: July 3, 2020

3.8K

Area of Science:

  • Behavioral Science
  • Medical Science
  • Social Science

Background:

  • Mediation analysis examines how a predictor (X) influences an outcome (Y) via an intervening mediator (M).
  • Traditional mediation methods often assume linear relationships between X, M, and Y.
  • Nonlinear relationships are common in mediation but often overlooked by existing methods.

Purpose of the Study:

  • To extend adaptive regression methods for assessing nonlinear mediation.
  • To incorporate monotonic relationships into mediation analysis.
  • To provide tools for situations where linear assumptions are insufficient.

Main Methods:

  • Adaptive regression techniques based on fractional polynomials are extended.
  • The methods assume monotonic relationships, aligning with directional theories in mediation.
  • Monotonic mediation and moderated monotonic mediation analyses are developed.

Main Results:

  • The study provides example analyses of linear and monotonic mediation.
  • The effect of family functioning (X) on child adaptation (Y) is mediated by management difficulty (M).
  • Simulation analyses are presented to validate the proposed methods.

Conclusions:

  • Adaptive methods offer an effective approach to mediation analysis with nonlinear monotonic relationships.
  • These methods enhance the understanding of complex interactions in various scientific fields.