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Light intensity modulation by coccoliths of Emiliania huxleyi as a micro-photo-regulator.

Mizukawa Y, Miyashita Y, Satoh M, Shiraiwa Y, Iwasaka M - Sci Rep (2015)

Bottom Line: The magnetic field effect is induced by the diamagnetic torque force directing the coccolith radial plane perpendicular to the applied magnetic fields at 400 to 500 mT.The detached coccolith scatters radially the light incident to its radial plane.The experimental results on magnetically oriented coccoliths show that an individual coccolith has a specific direction of light scattering, although the possible physiological effect of the coccolith remains for further study, focusing on the light-scattering anisotropies of coccoliths on living cells.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Advanced Sciences of Matter, Hiroshima University, Hiroshima 739-8527, Japan.

ABSTRACT
In this study, we present experimental evidence showing that coccoliths have light-scattering anisotropy that contributes to a possible control of solar light exposure in the ocean. Changing the angle between the incident light and an applied magnetic field causes differences in the light-scattering intensities of a suspension of coccoliths isolated from Emiliania huxleyi. The magnetic field effect is induced by the diamagnetic torque force directing the coccolith radial plane perpendicular to the applied magnetic fields at 400 to 500 mT. The developed technique reveals the light-scattering anisotropies in the 3-μm-diameter floating coccoliths by orienting themselves in response to the magnetic fields. The detached coccolith scatters radially the light incident to its radial plane. The experimental results on magnetically oriented coccoliths show that an individual coccolith has a specific direction of light scattering, although the possible physiological effect of the coccolith remains for further study, focusing on the light-scattering anisotropies of coccoliths on living cells.

No MeSH data available.


Related in: MedlinePlus

Light scattering changes in floating coccoliths in water with and without magnetic field exposure at 400 mT.An enhancement (a)–(c) and an inhibition (d)–(f) of light scattering were obtained when the incident light was parallel and perpendicular to the magnetic field, respectively. (a) Dark field image of coccoliths immediately before the magnetic field exposure, as well as an expanded image. Bar, 50 μm. (b) Enhancement of light scattering by a 400 mT magnetic field parallel to the dark field illumination. (c) Post-exposure images of coccoliths scattering light. (d) Pre-exposure image. Bar, 50 μm. (e) Inhibition of light scattering during the application of magnetic fields parallel to the incident light. (f) Post-exposure image. (g) Speculation and proposed model of the enhancement of light scattering in coccoliths floating in water when the coccolith orientation was affected by the diamagnetic torque force. The magnetic orientation of the coccoliths caused their radial plane to align perpendicular to the magnetic field. Consequently, the light scattered toward the objective lens became intense. The light scattering pattern (column in orange-yellow) become anisotropic and directed to the objective lens because the incident light faced the coccolith plate. (h) Isotropic light scattering in randomly oriented floating coccoliths. (i) A magnetic field orthogonal to the incident light caused the direction of the coccolith plates to be parallel to the angle of incidence of the light, and the light passed through the coccolith plates. Details of the mechanism are shown (j)–(k). (j) Radial plane of the backboard-facing incident light. The light is reflected to the side, and the increase in brightness was measured. (k) Incident light nearly parallel to the radial plane can be reflected by the curved surface in front or in back of the calcite board. In both cases, light scattering enhancements in the vertical direction can be detected when a coccolith is observed from the front or the back. In contrast, less light is scattered in the direction that is orthogonal to both the incident light and the magnetic field.
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f4: Light scattering changes in floating coccoliths in water with and without magnetic field exposure at 400 mT.An enhancement (a)–(c) and an inhibition (d)–(f) of light scattering were obtained when the incident light was parallel and perpendicular to the magnetic field, respectively. (a) Dark field image of coccoliths immediately before the magnetic field exposure, as well as an expanded image. Bar, 50 μm. (b) Enhancement of light scattering by a 400 mT magnetic field parallel to the dark field illumination. (c) Post-exposure images of coccoliths scattering light. (d) Pre-exposure image. Bar, 50 μm. (e) Inhibition of light scattering during the application of magnetic fields parallel to the incident light. (f) Post-exposure image. (g) Speculation and proposed model of the enhancement of light scattering in coccoliths floating in water when the coccolith orientation was affected by the diamagnetic torque force. The magnetic orientation of the coccoliths caused their radial plane to align perpendicular to the magnetic field. Consequently, the light scattered toward the objective lens became intense. The light scattering pattern (column in orange-yellow) become anisotropic and directed to the objective lens because the incident light faced the coccolith plate. (h) Isotropic light scattering in randomly oriented floating coccoliths. (i) A magnetic field orthogonal to the incident light caused the direction of the coccolith plates to be parallel to the angle of incidence of the light, and the light passed through the coccolith plates. Details of the mechanism are shown (j)–(k). (j) Radial plane of the backboard-facing incident light. The light is reflected to the side, and the increase in brightness was measured. (k) Incident light nearly parallel to the radial plane can be reflected by the curved surface in front or in back of the calcite board. In both cases, light scattering enhancements in the vertical direction can be detected when a coccolith is observed from the front or the back. In contrast, less light is scattered in the direction that is orthogonal to both the incident light and the magnetic field.

Mentions: In Fig. 4a, illumination from the side caused dynamic light scattering in the direction of observation. When exposed to a 400 mT magnetic field that was parallel to the incident light, the light scattering from the coccoliths was enhanced, as shown in Fig. 4b. The diamagnetic energy can modulate coccolith rotation due to Brownian motion, which produces a change in the light-scattering intensity. The effect was reversible and reproducible. After the magnetic field was switched off, the intensity returned to the level observed prior to the exposure. In the model shown in Fig. 4g, we proposed that the radial component in the coccolith was directed perpendicular to the applied magnetic field. Consequently, we speculated that the incident light was bent by the edge of the coccolith board (Fig. 4j) and scattered to the sides.


Light intensity modulation by coccoliths of Emiliania huxleyi as a micro-photo-regulator.

Mizukawa Y, Miyashita Y, Satoh M, Shiraiwa Y, Iwasaka M - Sci Rep (2015)

Light scattering changes in floating coccoliths in water with and without magnetic field exposure at 400 mT.An enhancement (a)–(c) and an inhibition (d)–(f) of light scattering were obtained when the incident light was parallel and perpendicular to the magnetic field, respectively. (a) Dark field image of coccoliths immediately before the magnetic field exposure, as well as an expanded image. Bar, 50 μm. (b) Enhancement of light scattering by a 400 mT magnetic field parallel to the dark field illumination. (c) Post-exposure images of coccoliths scattering light. (d) Pre-exposure image. Bar, 50 μm. (e) Inhibition of light scattering during the application of magnetic fields parallel to the incident light. (f) Post-exposure image. (g) Speculation and proposed model of the enhancement of light scattering in coccoliths floating in water when the coccolith orientation was affected by the diamagnetic torque force. The magnetic orientation of the coccoliths caused their radial plane to align perpendicular to the magnetic field. Consequently, the light scattered toward the objective lens became intense. The light scattering pattern (column in orange-yellow) become anisotropic and directed to the objective lens because the incident light faced the coccolith plate. (h) Isotropic light scattering in randomly oriented floating coccoliths. (i) A magnetic field orthogonal to the incident light caused the direction of the coccolith plates to be parallel to the angle of incidence of the light, and the light passed through the coccolith plates. Details of the mechanism are shown (j)–(k). (j) Radial plane of the backboard-facing incident light. The light is reflected to the side, and the increase in brightness was measured. (k) Incident light nearly parallel to the radial plane can be reflected by the curved surface in front or in back of the calcite board. In both cases, light scattering enhancements in the vertical direction can be detected when a coccolith is observed from the front or the back. In contrast, less light is scattered in the direction that is orthogonal to both the incident light and the magnetic field.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555034&req=5

f4: Light scattering changes in floating coccoliths in water with and without magnetic field exposure at 400 mT.An enhancement (a)–(c) and an inhibition (d)–(f) of light scattering were obtained when the incident light was parallel and perpendicular to the magnetic field, respectively. (a) Dark field image of coccoliths immediately before the magnetic field exposure, as well as an expanded image. Bar, 50 μm. (b) Enhancement of light scattering by a 400 mT magnetic field parallel to the dark field illumination. (c) Post-exposure images of coccoliths scattering light. (d) Pre-exposure image. Bar, 50 μm. (e) Inhibition of light scattering during the application of magnetic fields parallel to the incident light. (f) Post-exposure image. (g) Speculation and proposed model of the enhancement of light scattering in coccoliths floating in water when the coccolith orientation was affected by the diamagnetic torque force. The magnetic orientation of the coccoliths caused their radial plane to align perpendicular to the magnetic field. Consequently, the light scattered toward the objective lens became intense. The light scattering pattern (column in orange-yellow) become anisotropic and directed to the objective lens because the incident light faced the coccolith plate. (h) Isotropic light scattering in randomly oriented floating coccoliths. (i) A magnetic field orthogonal to the incident light caused the direction of the coccolith plates to be parallel to the angle of incidence of the light, and the light passed through the coccolith plates. Details of the mechanism are shown (j)–(k). (j) Radial plane of the backboard-facing incident light. The light is reflected to the side, and the increase in brightness was measured. (k) Incident light nearly parallel to the radial plane can be reflected by the curved surface in front or in back of the calcite board. In both cases, light scattering enhancements in the vertical direction can be detected when a coccolith is observed from the front or the back. In contrast, less light is scattered in the direction that is orthogonal to both the incident light and the magnetic field.
Mentions: In Fig. 4a, illumination from the side caused dynamic light scattering in the direction of observation. When exposed to a 400 mT magnetic field that was parallel to the incident light, the light scattering from the coccoliths was enhanced, as shown in Fig. 4b. The diamagnetic energy can modulate coccolith rotation due to Brownian motion, which produces a change in the light-scattering intensity. The effect was reversible and reproducible. After the magnetic field was switched off, the intensity returned to the level observed prior to the exposure. In the model shown in Fig. 4g, we proposed that the radial component in the coccolith was directed perpendicular to the applied magnetic field. Consequently, we speculated that the incident light was bent by the edge of the coccolith board (Fig. 4j) and scattered to the sides.

Bottom Line: The magnetic field effect is induced by the diamagnetic torque force directing the coccolith radial plane perpendicular to the applied magnetic fields at 400 to 500 mT.The detached coccolith scatters radially the light incident to its radial plane.The experimental results on magnetically oriented coccoliths show that an individual coccolith has a specific direction of light scattering, although the possible physiological effect of the coccolith remains for further study, focusing on the light-scattering anisotropies of coccoliths on living cells.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Advanced Sciences of Matter, Hiroshima University, Hiroshima 739-8527, Japan.

ABSTRACT
In this study, we present experimental evidence showing that coccoliths have light-scattering anisotropy that contributes to a possible control of solar light exposure in the ocean. Changing the angle between the incident light and an applied magnetic field causes differences in the light-scattering intensities of a suspension of coccoliths isolated from Emiliania huxleyi. The magnetic field effect is induced by the diamagnetic torque force directing the coccolith radial plane perpendicular to the applied magnetic fields at 400 to 500 mT. The developed technique reveals the light-scattering anisotropies in the 3-μm-diameter floating coccoliths by orienting themselves in response to the magnetic fields. The detached coccolith scatters radially the light incident to its radial plane. The experimental results on magnetically oriented coccoliths show that an individual coccolith has a specific direction of light scattering, although the possible physiological effect of the coccolith remains for further study, focusing on the light-scattering anisotropies of coccoliths on living cells.

No MeSH data available.


Related in: MedlinePlus