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Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
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In order to produce glucose, plants need to capture sufficient light energy. Many modern plants have evolved leaves specialized for light acquisition. Leaves can be only millimeters in width or tens of meters wide, depending on the environment. Due to competition for sunlight, evolution has driven the evolution of increasingly larger leaves and taller plants, to avoid shading by their neighbors with contaminant elaboration of root architecture and mechanisms to transport water and nutrients.
Potential Due to a Polarized Object01:29

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A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
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Bioluminescent Optogenetics 2.0: Harnessing Bioluminescence to Activate Photosensory Proteins In Vitro and In Vivo
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PHOTIC ORIENTATION BY TWO POINT-SOURCES OF LIGHT.

W H Mitchell1, W J Crozier

  • 1Laboratory of General Physiology, Harvard University, Cambridge.

The Journal of General Physiology
|October 30, 2009
PubMed
Summary
This summary is machine-generated.

This study presents general formulas for phototropic organism orientation under two-point light sources. Previously identified formulas are shown to be specific instances of these new general equations.

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Published on: July 21, 2018

Area of Science:

  • Plant Science
  • Biophysics
  • Photobiology

Background:

  • Phototropism is a key plant response to light.
  • Understanding orientation mechanisms is crucial for plant development.
  • Existing models often simplify light source conditions.

Purpose of the Study:

  • To derive general mathematical formulas for phototropic orientation.
  • To analyze organism orientation in a light field with two point sources.
  • To unify existing orientation formulas under a general framework.

Main Methods:

  • Mathematical derivation of orientation formulas.
  • Analysis of light vector interactions.
  • Comparative study with existing theoretical models.

Main Results:

  • General formulae for phototropic orientation were successfully derived.
  • The derived formulae account for two point-sources in the horizontal plane.
  • Previously established formulae were demonstrated as special cases of the general equations.

Conclusions:

  • The new general formulae provide a more comprehensive model for phototropism.
  • This work unifies and extends previous findings in phototropic orientation research.
  • The findings have implications for understanding plant behavior in complex light environments.