Responses of cercariae of Trichobilharzia ocellata to white light, monochromatic light, and irradiance reduction

1974 ◽  
Vol 52 (5) ◽  
pp. 575-579 ◽  
Author(s):  
D. G. S. Wright
Keyword(s):  
Energy Spectrum ◽  
White Light ◽  
Monochromatic Light ◽  
Light Irradiance ◽  
Equal Energy ◽  
Illuminance Level ◽  
Trichobilharzia Ocellata

Cercariae of Trichobilharzia ocellata exhibited a significant directed response to white light starting at an illuminance level of 0.35 lx. When exposed to an equal energy spectrum of monochromatic light (irradiance = 0.22 μW/cm2), the most significant directed response occurred at 500 nm. Swimming in response to illuminance reduction varies inversely as the preadaptation irradiance levels.

Responses of miracidia of Schistosoma mansoni to an equal energy spectrum of monochromatic light

1974 ◽  
Vol 52 (7) ◽  
pp. 857-859 ◽  
Author(s):  
D. G. S. Wright
Keyword(s):  
Energy Spectrum ◽  
Schistosoma Mansoni ◽  
Fresh Water ◽  
Monochromatic Light ◽  
Spectral Intensity ◽  
Percentage Composition ◽  
Light Irradiance ◽  
Equal Energy

An equal energy spectrum of monochromatic light (irradiance = 0.22 μW/cm2) caused miracidia of Schistosoma mansoni to respond maximally in a directed manner to wavelengths of 525 nm and 650 um. Miracidia of S. mansoni responded to wavelengths which make up the greatest percentage composition of spectral intensity in clear fresh water and muddy waters.

Responses of miracidia of Schistosomatium douthitti (Cort 1914) to monochromatic light

1972 ◽  
Vol 50 (2) ◽  
pp. 197-200 ◽  
Author(s):  
D. G. S. Wright ◽  
D. M. Lavigne ◽  
K. Ronald
Keyword(s):  
Energy Spectrum ◽  
Monochromatic Light ◽  
Equal Energy

When exposed to an equal energy spectrum (irradiance = 0.225 W/m2) from 450–650 nm miracidia of Schistosomatium douthitti exhibited a significant directed response to monochromatic light at 500 and 525 nm.

scholarly journals Spectral Tuning of White Light Allows for Strong Reduction in Melatonin Suppression without Changing Illumination Level or Color Temperature

2018 ◽  
Vol 33 (4) ◽  
pp. 420-431 ◽  
Author(s):  
Jan L. Souman ◽  
Tobias Borra ◽  
Iris de Goijer ◽  
Luc J. M. Schlangen ◽  
Björn N. S. Vlaskamp ◽  
...  
Keyword(s):  
White Light ◽  
High Power ◽  
Spectral Power ◽  
Monochromatic Light ◽  
Action Spectrum ◽  
Color Temperature ◽  
Light Spectrum ◽  
Melatonin Suppression ◽  
Dim Light ◽  
Melatonin Production

Studies with monochromatic light stimuli have shown that the action spectrum for melatonin suppression exhibits its highest sensitivity at short wavelengths, around 460 to 480 nm. Other studies have demonstrated that filtering out the short wavelengths from white light reduces melatonin suppression. However, this filtering of short wavelengths was generally confounded with reduced light intensity and/or changes in color temperature. Moreover, it changed the appearance from white light to yellow/orange, rendering it unusable for many practical applications. Here, we show that selectively tuning a polychromatic white light spectrum, compensating for the reduction in spectral power between 450 and 500 nm by enhancing power at even shorter wavelengths, can produce greatly different effects on melatonin production, without changes in illuminance or color temperature. On different evenings, 15 participants were exposed to 3 h of white light with either low or high power between 450 and 500 nm, and the effects on salivary melatonin levels and alertness were compared with those during a dim light baseline. Exposure to the spectrum with low power between 450 and 500 nm, but high power at even shorter wavelengths, did not suppress melatonin compared with dim light, despite a large difference in illuminance (175 vs. <5 lux). In contrast, exposure to the spectrum with high power between 450 and 500 nm (also 175 lux) resulted in almost 50% melatonin suppression. For alertness, no significant differences between the 3 conditions were observed. These results open up new opportunities for lighting applications that allow for the use of electrical lighting without disturbance of melatonin production.

Physical and Mathematical Considerations About Laser Perimetry

1974 ◽  
Vol 23 (S1) ◽  
pp. 349-351 ◽  
Author(s):  
L. Favella ◽  
L. Liuzzi ◽  
F. Bartoli
Keyword(s):  
White Light ◽  
Laser Light ◽  
Monochromatic Light ◽  
Neon Laser ◽  
Helium Neon Laser ◽  
Helium Neon ◽  
Mathematical Characteristics

The physical and mathematical characteristics of white light, monochromatic light, and laser light, are discussed with reference to the advantages offered by perimetry using a red helium-neon laser.

scholarly journals Progress in the Measurement of Solar Magnetic Fields

1993 ◽  
Vol 141 ◽  
pp. 149-155 ◽  
Author(s):  
Guoxiang Ai
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
White Light ◽  
Historical Development ◽  
Solar Magnetic Field ◽  
Solar Physics ◽  
Monochromatic Light ◽  
Velocity Fields ◽  
Solar Magnetic Fields ◽  
Optical Instruments

AbstractThe historical development of optical instruments for solar physics is outlined, from white light to unpolarized and polarized monochromatic light, to Stokes profiles and simultaneous fields of view, from points to lines, plane to cube. An evolutionary series and classificaton of instruments for the solar magnetic field is described. As a next step the 2-D real time polarizing spectrograph has been proposed. The planned instruments in China for measurements of solar magnetic and velocity fields are briefly introduced.

scholarly journals On the luminosity curves of persons having normal and abnormal colour vision

1913 ◽  
Vol 88 (604) ◽  
pp. 404-428 ◽  
Keyword(s):  
White Light ◽  
Wave Length ◽  
Monochromatic Light ◽  
Absolute Intensity ◽  
White Patch ◽  
The Press ◽  
Colour Sense ◽  
Intimate Relation ◽  
Series Of Experiments ◽  
Pass Through

1. When reading a recent paper before the Royal Society, and also in the Press, Dr. Edridge Green has stated that he can find no connection between the luminosity and the colour sense of persons having either normal or abnormal colour sensations. Since I feel that to allow such a statement to go unchallenged might be interpreted as meaning that no such connection could be shown to exist, I propose in the following paper to place before the Society some of the evidence which indicated that there is in reality a very intimate relation between luminosity and colour sense. The results given include a small part of those which have been obtained in a series of experiments which have occupied the last two years and form part of investigation which is still in progress. The term “luminosity” as used in this paper has the following meaning: Suppose that light from some source, such as the electric arc, is admitted to a spectroscope by means of which a real pure spectrum is produced, and that a slide in the plane in which the spectrum is formed carries a slit of fixed width. Light of sensibly one wave-length, i. e. monochromatic light, will pass through this slit, and by means of a lens placed in the beam of this light an image of the first face of the prism which is used to from the spectrum can be formed on a screen. In this way a monochromatic patch of light is obtained, the brightness of which depends on the nature of the source of light, the width of the collimator slit, the width of the slit placed in the spectrum, which for short will be called the movable slit, and the dimensions of the lenses employed. Further, if alongside this coloured patch is formed a white patch of light produced by light which proceeds from the same source but has not undergone dispersion, and that by some means or other the intensity of this white light is altered till the coloured and white light, measured in any arbitrary units, measure the luminosity of the light of that colour which is passing through the movable slit. Since the unit in which the white light is measured is arbitrary, we are not concerned with the absolute intensity of illumination of the white patch, and may use any device we like to alter the quantity of white light which falls on the screen so long as we are able to measure the ratio of the quantity of light employed in different experiments. It will further be observed that for any given person the measurement of the luminosity of a given coloured light in the spectrum involves the comparsion of the brightness of the coloured patch as it appears to him with the brightness of the white patch as it appears to him.

scholarly journals Behavioral Responses of the SnailLymnaea acuminatatowards Photo and Chemo Attractants: A New Step in Control Program of Fasciolosis

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Anupam Pati Tripathi ◽  
V. K. Singh ◽  
D. K. Singh
Keyword(s):  
White Light ◽  
Fasciola Hepatica ◽  
Signal Transmission ◽  
Monochromatic Light ◽  
Behavioral Responses ◽  
Control Program ◽  
Light Control ◽  
Maximum Change ◽  
Food Borne ◽  
The Brain

Fasciolosis is water and food borne disease, caused byFasciola hepaticaandF. gigantica. SnailLymnaea acuminatais an intermediate host of these flukes. Snail control is one of the major methods to reduce the incidences of fasciolosis. Trapping of snails with the help of photo- and chemoattractants for treatment purposes will be a new tool in control program of fasciolosis. The present study shows that maximum numbers of snails were attracted (52 to 60%), when exposed to photo- and chemostimulant simultaneously, rather than when only chemo- (control) (18 to 24%) or photo- (control) (14 to 19%) stimulus was given. Maximum change in AChE activity in nervous tissue was observed when red monochromatic light was used (258.37% of white light control) as opposed to blue (243.44% of white light control) and orange (230.37% of white light control). The exposure of light directly stimulated the photoreceptors in eye which transmit the signals through nerves to the brain and snail response accordingly. In this signal transmission AChE is one of the important enzymes involved in this process.

Time Dependence of the Metastable, Optically-Induced Esr in a-Si:H

1986 ◽  
Vol 70 ◽  
Author(s):  
C. Lee ◽  
W. D. Ohlsen ◽  
P. C. Taylor
Keyword(s):  
Time Dependence ◽  
Spin Density ◽  
Power Law ◽  
White Light ◽  
Monochromatic Light ◽  
Extended Range ◽  
Unique Power ◽  
Spin Densities ◽  
Optically Induced

ABSTRACTThe occurrence of optically-induced, metastable changes in the paramagnetism in films of a-Si:H is well known. The effect was first observed with white light in powdered samples, but recent experiments with both white and monochromatic light incident on films on substrates have observed a similar effect. This optically-induced ESR appears to be stable at temperatures < 400 K. Typical inducing curves for samples with initial dark spin densities ns > 1016 spins/cm3 approach a power law behavior (ns ∼ t1 / 3) at long times. However, when the dark spin density is less than 1016 spins/cm3, the samples exhibit an inducing curve (on a log-log scale) with a continuously decreasing slope. The curve does not exhibit a unique power law behavior over an extended range of time and is at all times < t1 / 3.

Optical Absorption of Deep Defects in Neutron Irradiated Semi-Insulating GaAs.

1989 ◽  
Vol 163 ◽  
Author(s):  
M. O. Manasreh ◽  
P. J. Pearah
Keyword(s):  
Optical Absorption ◽  
Thermal Neutron ◽  
Infrared Absorption ◽  
White Light ◽  
Monochromatic Light ◽  
Annealing Conditions ◽  
Lec Gaas ◽  
Order Of Magnitude ◽  
Insulating Liquid ◽  
Absorption Technique

AbstractTwo defects were observed in thermal neutron irradiated semi-insulating liquid-encapsulated Czochralski (LEC) GaAs materials by using the infrared absorption technique. The first defect was observed before thermal annealing and it has a broad peak at ~0.83 eV. The second defect was observed after annealing the sample at 250 °C for 15 min. The latter defect is an EL2 - like defect, but is thermally unstable at 400 °C with a concentration of about an order of magnitude larger than [EL2] observed in as grown LEC materials. Both defects were found to photoquench with white light or 1.1 eV monochromatic light at 9 K and thermally recovered at 150 K. The concentration of the EL2 - like defect is reduced from 8.5×1016cm3 after annealing the sample at 300 °C for 15 min to 2×1016cm-3 after annealing at 400 °C for 15 min. This defect becomes unquenchable after the latter annealing conditions. An explanation for this behavior is offered.

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