The aligning effect of light flicker on phototaxis of the ambrosia beetle Trypodendron lineatum (Olivier)

1968 ◽  
Vol 46 (3) ◽  
pp. 602-603 ◽  
Author(s):  
K. Graham ◽  
Isabelle A. Moeck
Keyword(s):  
Light Intensity ◽  
Ambrosia Beetle ◽  
Trypodendron Lineatum ◽  
Chemical Attractants ◽  
Light Flicker ◽  
Effect Of Light

A light which was flickered at approximately 5 cycles per second provoked a more direct guided response in the ambrosia beetle Trypodendron lineatum (Olivier) than did a steady source of the same intensity. Among the principal implications are those which concern the use of the beetles in bioassay of chemical attractants in which light is used as an opposing stimulus. The light intensity should be at least stabilized, and preferably flickered at an appropriate frequency.

Anaerobic induction of primary chemical attractancy for ambrosia beetles

1968 ◽  
Vol 46 (5) ◽  
pp. 905-908 ◽  
Author(s):  
K. Graham
Keyword(s):  
Experimental Evidence ◽  
Oxygen Deficiency ◽  
Causal Factor ◽  
Ambrosia Beetle ◽  
Anaerobic Conditions ◽  
Trypodendron Lineatum ◽  
Ambrosia Beetles ◽  
Fermentative Metabolism ◽  
Chemical Attractants ◽  
Anaerobic Induction

Experimental evidence supports a hypothesis that oxygen deficiency may be a causal factor in the formation of chemical attractants for the ambrosia beetle Trypodendron lineatum (Olivier). Detectable attractancy can be induced by anaerobic conditions at 20 °C, imposed for 4 hours on fresh sapwood. Maximum attractancy develops within 24 hours of anaerobic processing. The hypothesis proposes that in a log or dying tree stagnation of the translocative and pneumatic systems leads to deficiency of oxygen at the active metabolic centers. The consequent change from oxidative to fermentative metabolism thus induces attractant formation.

Effect of light intensity on the ultrastructure of the filamentous cyanobacterium, Anabaena variabilis

1988 ◽  
Vol 46 ◽  
pp. 300-301
Author(s):  
C. S. Bricker ◽  
S. R. Barnum ◽  
B. Huang ◽  
J. G. Jaworskl
Keyword(s):  
Fatty Acid ◽  
Light Intensity ◽  
Acid Content ◽  
Fatty Acid Content ◽  
Anabaena Variabilis ◽  
Chloroplast Envelope ◽  
Major Constituent ◽  
Filamentous Cyanobacterium ◽  
Photosynthetic Membrane ◽  
Effect Of Light

Cyanobacteria are Gram negative prokaryotes that are capable of oxygenic photosynthesis. Although there are many similarities between eukaryotes and cyanobacteria in electron transfer and phosphorylation during photosynthesis, there are two features of the photosynthetic apparatus in cyanobacteria which distinguishes them from plants. Cyanobacteria contain phycobiliproteins organized in phycobilisomes on the surface of photosynthetic membrane. Another difference is in the organization of the photosynthetic membranes. Instead of stacked thylakolds within a chloroplast envelope membrane, as seen In eukaryotes, IntracytopIasmlc membranes generally are arranged in three to six concentric layers. Environmental factors such as temperature, nutrition and light fluency can significantly affect the physiology and morphology of cells. The effect of light Intensity shifts on the ultrastructure of Internal membrane in Anabaena variabilis grown under controlled environmental conditions was examined. Since a major constituent of cyanobacterial thylakolds are lipids, the fatty acid content also was measured and correlated with uItrastructural changes. The regulation of fatty acid synthesis in cyanobacteria ultimately can be studied if the fatty acid content can be manipulated.

Effect of light intensity and water aging on surface hardness of dental resin-composites

2019 ◽  
Vol 64 (11) ◽  
pp. 1007-1014
Author(s):  
Tong XU ◽  
◽  
Jia-Hui ZHANG ◽  
Zhao-Ying LIU ◽  
Xuan LI ◽  
...  
Keyword(s):  
Light Intensity ◽  
Surface Hardness ◽  
Resin Composites ◽  
Dental Resin ◽  
Dental Resin Composites ◽  
Effect Of Light

LINEATIN ENANTIOMER PREFERENCE, FLIGHT PERIODS, AND EFFECT OF PHEROMONE CONCENTRATION AND TRAP LENGTH ON THREE SYMPATRIC SPECIES OF TRYPODENDRON (COLEOPTERA: SCOLYTIDAE)

2000 ◽  
Vol 132 (6) ◽  
pp. 877-887 ◽  
Author(s):  
B.S. Lindgren ◽  
S.E.R. Hoover ◽  
A.M. MacIsaac ◽  
C.I. Keeling ◽  
K.N. Slessor
Keyword(s):  
Sex Ratio ◽  
Reproductive Isolation ◽  
Release Rate ◽  
Sympatric Species ◽  
Ambrosia Beetle ◽  
Flight Period ◽  
Trypodendron Lineatum ◽  
Temporal Separation ◽  
Baited Traps ◽  
Pheromone Concentration

AbstractThe effects of lineatin enantiomer ratios, lineatin release rate, and trap length on catches and the flight periods of three sympatric species of Trypodendron Stephens were investigated in field bioassays using multiple-funnel traps. The ambrosia beetle, Trypodendron betulae Swaine, was caught in similar numbers in baited traps and blank control traps, showing that this species does not respond to lineatin. Our results confirmed that Trypodendron lineatum (Olivier) is attracted only to (+)-lineatin. Trypodendron rufitarsus (Kirby) and Trypodendron retusum (LeConte) were shown to utilize lineatin and like T. lineatum were caught only when (+)-lineatin was present. These results indicate that lineatin does not govern reproductive isolation among these three species. There was no effect by (+)-lineatin release rate within the range tested. The flight of T. rufitarsus commenced earlier and ceased before the peak of the T. lineatum flight, suggesting that temporal separation may be an important component of reproductive isolation between these two species. The flight period of T. retusum was similar to that of T. lineatum. Host odours may aid in reproductive isolation of these two species. Enantiomer blend did not significantly affect sex ratio in any species; however, sex ratio differed among species, indicating that different species responded differently to the traps or that natural sex ratios differ. Catches of T. rufitarsus and T. retusum increased with trap length when pheromone release per trap was held constant and when release was held constant relative to trap length. Trap length and release rate did not affect sex ratio.

scholarly journals Effect of Light Intensity and Quality on Growth Rate and Composition of Chlorella vulgaris

Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 31 ◽  
Author(s):  
Maria N. Metsoviti ◽  
George Papapolymerou ◽  
Ioannis T. Karapanagiotidis ◽  
Nikolaos Katsoulas
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Chlorella Vulgaris ◽  
Lipid Content ◽  
Growth Rates ◽  
Solar Irradiance ◽  
White Led ◽  
Microalgal Biomass ◽  
Nm Range ◽  
Effect Of Light

In this research, the effect of solar irradiance on Chlorella vulgaris cultivated in open bioreactors under greenhouse conditions was investigated, as well as of ratio of light intensity in the 420–520 nm range to light in the 580–680 nm range (I420–520/I580–680) and of artificial irradiation provided by red and white LED lamps in a closed flat plate laboratory bioreactor on the growth rate and composition. The increase in solar irradiance led to faster growth rates (μexp) of C. vulgaris under both environmental conditions studied in the greenhouse (in June up to 0.33 d−1 and in September up to 0.29 d−1) and higher lipid content in microalgal biomass (in June up to 25.6% and in September up to 24.7%). In the experiments conducted in the closed bioreactor, as the ratio I420–520/I580–680 increased, the specific growth rate and the biomass, protein and lipid productivities increased as well. Additionally, the increase in light intensity with red and white LED lamps resulted in faster growth rates (the μexp increased up to 0.36 d−1) and higher lipid content (up to 22.2%), while the protein, fiber, ash and moisture content remained relatively constant. Overall, the trend in biomass, lipid, and protein productivities as a function of light intensity was similar in the two systems (greenhouse and bioreactor).

scholarly journals PHOTOKINESIS AND TONIC EFFECT OF LIGHT IN UNIONICOLA

1932 ◽  
Vol 16 (2) ◽  
pp. 349-355 ◽  
Author(s):  
John H. Welsh
Keyword(s):  
Light Intensity ◽  
Simple Relation ◽  
Combined Effect ◽  
Direct Proportion ◽  
Water Mite ◽  
Locomotor Muscles ◽  
Leg Movement ◽  
Changing Light ◽  
Effect Of Light

1. The speed of progression of Unionicola, a water mite, is influenced by light; and over a certain range increases as a function of the light intensity. 2. The relation between speed and light intensity is not a simple one, as the speed of progression is due to the combined effect of amplitude of steps and frequency of leg movement. 3. The amplitude of stride increases in direct proportion to the logarithm of the light intensity, while the frequency of stepping has no such simple relation to intensity. 4. The change in length of stride with changing light intensity indicates a tonic effect of light on the locomotor muscles. Such an effect has been observed previously in studies of orientation, due to unequal illumination, which produces changes in posture.

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