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

Drug Absorption: Factors Affecting GI Absorption01:19

Drug Absorption: Factors Affecting GI Absorption

6.4K
The process of oral drug absorption can be influenced by several factors. Weakly acidic drugs tend to be absorbed more readily from the stomach due to their nonionized state. However, absorption may be less efficient in the upper intestine, where drugs are often ionized. Interestingly, despite the stomach's apparent advantage for drug absorption, its mucous layer can hinder diffusion. Its surface area is also smaller than the intestine's, which can further slow down the absorption rate.
6.4K
Fixation and Sectioning01:03

Fixation and Sectioning

8.0K
Two basic types of preparation are used to visualize specimens with a light microscope: wet mounts and fixed specimens.
The simplest type of preparation is the wet mount, in which the specimen is placed in a drop of liquid on the slide. A liquid specimen can be directly deposited on the slide using a dropper. Solid specimens, such as skin scraping, can be placed on the slide before adding a drop of liquid to prepare the wet mount. Sometimes the liquid is simply water, but stains are often added...
8.0K
Carbon-dioxide Fixation01:28

Carbon-dioxide Fixation

749
Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...
749
Absorption of Radiation01:05

Absorption of Radiation

1.3K
The rate of heat transfer by emitted radiation is described by the Stefan-Boltzmann law of radiation:
1.3K
Protein Absorption01:12

Protein Absorption

1.1K
Proteins in the gastrointestinal tract typically come from food, but they can also originate from disintegrated cells or secreted enzymes. In the stomach, the enzyme pepsin breaks down these proteins into polypeptides. The fragments then move into the duodenum as a semi-fluid mass called chyme. Pancreatic proteases, such as trypsin and chymotrypsin, and intestinal brush border enzymes like carboxypeptidases further dismantle the polypeptides into tripeptides, dipeptides, and free amino acids.
1.1K
Lipid Absorption01:24

Lipid Absorption

2.8K
Dietary triglycerides from chyme in the duodenum are mixed with bile salts produced by the liver to emulsify fats. As a result, large droplets are broken down into smaller ones, increasing the surface area for enzymatic action. Once emulsified, pancreatic lipases hydrolyze the triglycerides into free fatty acids and monoglycerides.
These breakdown products bind with bile salts and lecithin to form micelles, which quickly pass between microvilli to come in close contact with the apical...
2.8K

You might also read

Related Articles

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

Sort by
Same author

Niche Overlap Is Not Enough: Same Overlap, Contrasting Fluctuations.

Ecology letters·2026
Same author

A metric for tradable biodiversity credits quantifying impacts on global extinction risk.

Journal of industrial ecology·2026
Same author

The dominant-egalitarian transition in species-rich communities.

eLife·2025
Same author

Interaction network structures in competitive ecosystems.

Physical review. E·2025
Same author

Population dynamics in a time-varying environment with fat-tailed correlations.

Physical review. E·2024
Same author

Processes governing species richness in communities exposed to temporal environmental stochasticity: A review and synthesis of modelling approaches.

Mathematical biosciences·2023
Same journal

The male-biased sex ratio in humans and its role in the transition from promiscuity to pair bonding.

Journal of theoretical biology·2026
Same journal

Quantifying the counter-intuitive effects of vaccination by coupling the transmission dynamics of COVID-19 and the evolution of human behaviors.

Journal of theoretical biology·2026
Same journal

An integrative model of FGF2-induced signaling and muscle cell proliferation.

Journal of theoretical biology·2026
Same journal

A hybrid reaction-diffusion and mechanical stimulus model for mandibular bone remodeling under chewing and vibratory loading.

Journal of theoretical biology·2026
Same journal

Integrated tick management strategies in fragmented peridomestic environments.

Journal of theoretical biology·2026
Same journal

Joint likelihood-free inference of the number of selected single nucleotide polymorphisms and their selection coefficients in an evolving population.

Journal of theoretical biology·2026
See all related articles

Related Experiment Video

Updated: Feb 15, 2026

Measuring Microbial Mutation Rates with the Fluctuation Assay
07:44

Measuring Microbial Mutation Rates with the Fluctuation Assay

Published on: November 28, 2019

25.0K

Fixation and absorption in a fluctuating environment.

Matan Danino1, Nadav M Shnerb1

  • 1Department of Physics, Bar-Ilan University, Ramat-Gan IL52900, Israel.

Journal of Theoretical Biology
|January 14, 2018
PubMed
Summary
This summary is machine-generated.

This study models mutant fixation or extinction in finite populations with fluctuating selection. It provides new formulas for fixation probability and time, bridging constant selection and neutral dynamics.

Keywords:
AbsorptionDemographic stochasticityDriftEnvironmental stochasticityEvolutionFixationSelection

More Related Videos

Rapid Repetition Rate Fluctuation Measurement of Soliton Crystals in a Microresonator
07:42

Rapid Repetition Rate Fluctuation Measurement of Soliton Crystals in a Microresonator

Published on: December 15, 2021

3.6K
Determination of the Absorption, Translocation, and Distribution of Imidacloprid in Wheat
06:11

Determination of the Absorption, Translocation, and Distribution of Imidacloprid in Wheat

Published on: April 28, 2023

2.4K

Related Experiment Videos

Last Updated: Feb 15, 2026

Measuring Microbial Mutation Rates with the Fluctuation Assay
07:44

Measuring Microbial Mutation Rates with the Fluctuation Assay

Published on: November 28, 2019

25.0K
Rapid Repetition Rate Fluctuation Measurement of Soliton Crystals in a Microresonator
07:42

Rapid Repetition Rate Fluctuation Measurement of Soliton Crystals in a Microresonator

Published on: December 15, 2021

3.6K
Determination of the Absorption, Translocation, and Distribution of Imidacloprid in Wheat
06:11

Determination of the Absorption, Translocation, and Distribution of Imidacloprid in Wheat

Published on: April 28, 2023

2.4K

Area of Science:

  • Population Genetics
  • Evolutionary Biology
  • Community Ecology

Background:

  • The fate of a single mutant in a finite population is a core problem in evolutionary dynamics.
  • Classical models often assume neutral dynamics or constant selection, but real-world selection pressures fluctuate over time (temporal environmental stochasticity).

Purpose of the Study:

  • To develop a generic model for systems with demographic noise and fluctuating selection.
  • To derive asymptotic formulas for fixation probability, mean fixation time, and mean absorption time in such systems.

Main Methods:

  • Developed a mathematical model incorporating demographic stochasticity (drift) and time-varying selection.
  • Analyzed the system using asymptotic analysis for large population sizes (N).
  • Characterized fluctuating selection by time-averaged fitness (s0) and fluctuation parameters (amplitude γ, correlation time δ).

Main Results:

  • Derived asymptotic formulas for fixation probability, mean time to fixation, and mean time to absorption.
  • The derived expressions successfully interpolate between the limits of constant selection (γ→0) and time-averaged neutral dynamics (s0=0).

Conclusions:

  • The study provides a theoretical framework to understand mutant dynamics under fluctuating selection.
  • The new formulas offer valuable tools for analyzing evolutionary processes in environments with temporal variability.