Annual Growth Rings
Annual Growth Rings - Related Videos
08:00
Directed Cellular Self-Assembly to Fabricate Cell-Derived Tissue Rings for Biomechanical Analysis and Tissue Engineering
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Cited by 39 •
2011
This article outlines a versatile method to create cell-derived tissue rings by cellular self-assembly. Smooth muscle cells seeded into ring-shaped agarose wells aggregate and contract to form robust three-dimensional (3D) tissues within 7 days. Millimeter-scale tissue rings are conducive to mechanical testing and serve as building blocks for tissue assembly.
09:20
The Assembly and Application of 'Shear Rings': A Novel Endothelial Model for Orbital, Unidirectional and Periodic Fluid Flow and Shear Stress
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Cited by 10 •
2016
Different levels and patterns of fluid shear are known to modulate endothelial gene expression, phenotype and susceptibility to disease. We discuss the assembly and use of 'shear rings': a model that produces unidirectional, periodic shear stress patterns. Shear rings are simple to assemble, economical and can produce high cell yields.
10:45
In Situ Visualization of Axon Growth and Growth Cone Dynamics in Acute Ex Vivo Embryonic Brain Slice Cultures
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Cited by 4 •
2021
This protocol demonstrates a straightforward and robust method to study in situ axon growth and growth cone dynamics. It describes how to prepare ex vivo physiologically relevant acute brain slices and provides a user-friendly analysis pipeline.
11:46
Axon Stretch Growth: The Mechanotransduction of Neuronal Growth
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Cited by 30 •
2011
A unique tissue engineering method was developed to elongate numerous nerve fibers in culture by recapitulating axon stretch growth; a form of nervous system growth whereby nerves elongate in conjunction with growth of the enlarging body.
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Population Growth - Student Protocol
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2019
Exponential Population Growth Model ExpandNOTE: In these experiments you will use computer software to simulate different types of growth models. HYPOTHESES: The experimental hypothesis might be that if we increase either R, the reproductive rate or the initial population size, NT, that this will increase the population size after 10 generations in an exponential growth model compared to unmanipulated control populations. The null hypothesis may be that populations of different R and initial...
FAQs
The visible boundary is produced by a seasonal shift in cambial activity, not merely by a change in wood color. During favorable spring growth, the cambium makes earlywood that is lighter and less dense; as growth slows, it produces darker, denser latewood. That density transition marks the end of one growth phase and makes successive annual layers distinguishable.
These stresses can reduce growth, modify ring width or structure, or interrupt the normal sequence of earlywood and latewood. As a result, a ring may not show the expected regular pattern for that period. Interpreting such irregularities helps biologists connect changes in wood formation with environmental stress, disturbance, or damage experienced by the tree.
Ring width and structure preserve complementary information about a tree’s growth history. Their variation records how development changed across successive periods and can reveal responses to environmental conditions. Analyzing both characteristics supports estimates of tree age, reconstruction of past climate and ecological disturbance, and evaluation of long-term forest health.
Researchers estimate age by examining the sequence of successive growth layers and determining how many annual periods it represents. Each completed layer contributes to the tree’s chronological record, while irregular or interrupted patterns require careful interpretation. This approach links a biological structure directly to the duration of the tree’s growth history.
Researchers compare changes in ring width and structure across successive growth periods to identify environmental responses preserved in wood. Reduced or altered growth can correspond with drought, unusual temperatures, injury, or other disturbances described in the record. These patterns allow ring analysis to extend biological observations into earlier climate and ecological history.
Each successive layer occupies a position in a tree’s growth history, creating a time-ordered biological record within the wood. Analyzing that record can help establish when the material formed. This application extends the value of ring analysis beyond living trees and connects plant development with the study of wooden objects and materials.
Long-term patterns in ring width and structure show how trees responded to changing environmental conditions over many growth periods. Persistent reductions, unusual structures, or signs of interrupted growth can indicate recurring stress or disturbance. Examining these records gives biologists a historical perspective on forest condition rather than relying only on present-day observations.