Related Experiment Video
Updated: May 29, 2026
11:41
Real Time and Repeated Measurement of Skeletal Muscle Growth in Individual Live Zebrafish Subjected to Altered Electrical Activity
Published on: June 16, 2022
Summary
Human growth involves both size (amplitude) and maturation speed (tempo). Separating these components is crucial for accurate assessment, especially considering environmental impacts on tempo.
Area of Science:
- Human growth and development
- Biometrics
- Pediatrics
Background:
- Growth is typically measured by physical time, but this doesn't reflect internal maturation dynamics.
- Children mature at different rates, making calendar time an inconsistent measure of developmental stage.
Purpose of the Study:
- To differentiate and quantify the two primary components of height variance: growth tempo and amplitude.
- To highlight the importance of assessing developmental tempo in child and adolescent growth.
Main Methods:
- Utilized Functional Data Analysis and Principal Component Analysis.
- Statistically separated and quantified tempo and amplitude as sources of height variance.
Main Results:
- Identified tempo and amplitude as the two main sources of height variance.
- Demonstrated that developmental tempo is more sensitive to nutrition, health, and environmental stress than amplitude.
- Catch-up growth phenomena are largely tempo-related and may not impact final height (amplitude).
Conclusions:
- Accurate growth analysis requires disentangling amplitude and tempo.
- Assessing developmental tempo is integral to evaluating child and adolescent growth.
- There is a need for practical tools to analyze individual growth patterns, separating tempo and amplitude.
Related Concept Videos
01:26Exponential Equations for Modeling Growth
Exponential models are essential for describing rapid, multiplicative changes in natural systems, such as population growth. When a population doubles at regular intervals, the process can be modeled using a suitable base. For instance, a bacterial culture that doubles every three hours follows the model n(t)=n0⋅2t/3, where n(t) is the population at the time t.A more general model uses the natural base e, especially for continuous growth. This takes the form n(t)=n0⋅ert, where r is the relative...
01:29Exponential Growth
Bacterial populations exhibit exponential growth when conditions such as nutrient availability and temperature are favorable. In this phase, cells reproduce through binary fission, where each cell divides into two identical daughter cells. This process causes the population to double at regular intervals, resulting in a growth rate that is directly proportional to the current number of cells. As the population increases, the number of new cells formed during each generation also grows, creating...
01:10Wave Parameters
The simplest mechanical waves are associated with simple harmonic motion and repeat themselves for several cycles. These simple harmonic waves can be modeled using a combination of sine and cosine functions. Consider a simplified surface water wave that moves across the water's surface. Unlike complex ocean waves, in surface water waves, water moves vertically, oscillating up and down, whereas the disturbance of the wave moves horizontally through the medium. If a seagull is floating on the...
01:28Bacterial Growth Curve
The bacterial growth curve is a fundamental concept in microbiology that describes the dynamics of bacterial population growth in a closed system with controlled environmental conditions, such as temperature and nutrient availability. This curve is divided into four distinct phases: lag, log (exponential), stationary, and death phases, each reflecting a unique stage of bacterial adaptation and growth. During the lag phase, bacteria acclimate to their surroundings by synthesizing essential...
00:57Population Growth
Population size is dynamic, increasing with birth rates and immigration, and decreasing with death rates and emigration. In ideal conditions with unlimited resources, populations can increase exponentially, which plots as a J-shaped growth rate curve of population size against time. This type of curve is characteristic of newly-introduced invasive species, or populations that have suffered catastrophic declines and are rebounding.
01:27Microbial Growth Measurement: Indirect Methods
Estimating microbial growth is essential for understanding population dynamics and environmental adaptations. Indirect methods provide valuable insights by measuring parameters such as turbidity, metabolic activity, and biomass, enabling efficient and reproducible assessments.During exponential growth, microbial cells scatter light proportionally to their biomass, a principle used in turbidity measurements. About one million cells per milliliter produce detectable scattering, which a...