Brewster's dark patch: a neglected optical phenomenon in the landscape

Weather ◽  
2019 ◽  
Vol 74 (4) ◽  
pp. 154-155
Author(s):  
G. P. Können
Keyword(s):  
Optical Phenomenon ◽  
Dark Patch

scholarly journals The dark-ventral-patch of male red deer, a sexual signal that conveys the degree of involvement in rutting behavior

BMC Zoology ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Eva de la Peña ◽  
Javier Pérez-González ◽  
José Martín ◽  
Giovanni Vedel ◽  
Juan Carranza
Keyword(s):  
Sexual Behaviors ◽  
Red Deer ◽  
Decisive Role ◽  
Female Mate Choice ◽  
Doñana National Park ◽  
Sexual Signal ◽  
Mating Competition ◽  
Dark Patch ◽  
Rutting Behavior

Abstract Background In polygynous mammals, signalling may play a decisive role in mating behavior, mediating the intensity of male fights and female mate choice. During the rutting season, male red deer may show a visible dark patch in their ventral fur. Recently, this patch has been suggested to act as a flexible sexual signal, due to its relationships with other variables such as age, body size, antler development, volatile compounds, or the competitive environment. The analysis of fur pigmentation at the ventral patch suggests that this might also visually indicate the male intrinsic predisposition to take part in mating competition. Results To assess the possible role of this trait as a communicative signal related to mate competition, we used red deer behavioral observations during the rut in Doñana National Park (Spain) to examine the link between the degree of expression of the dark ventral patch and the rutting activity (assessed from both intra-and-inter-sexual behaviors). Consistent with our predictions, we found in a field study that males with large dark patches showed a higher frequency of rutting behaviors (mainly roaring and flehmen), more interactions with females, and attained larger harem sizes. Conclusions The dark ventral patch was a better predictor of male behavior than antler tines or territory holding, thus standing as a short-term indicator of male willingness to invest in mating competition.

scholarly journals Monochromatic Conical IR Emission from Decaying KrF Laser Filaments in Xenon as Coherent Stimulated Four-Wave Mixing Process

Photonics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 47
Author(s):  
Igor V. Smetanin ◽  
Alexey V. Shutov ◽  
Nikolay N. Ustinovskii ◽  
Vladimir D. Zvorykin ◽  
Anna V. Bogatskaya ◽  
...  
Keyword(s):  
Transverse Relaxation Time ◽  
Four Wave Mixing ◽  
Theoretical Background ◽  
Wave Mixing ◽  
Mixing Process ◽  
Optical Phenomenon ◽  
Coherent Interaction ◽  
Conical Emission ◽  
Krf Laser ◽  
Ir Emission

We develop theoretical background for the new nonlinear optical phenomenon of narrowly directed monochromatic IR conical emission which has been recently observed when 248-nm UV filaments propagate in xenon (V. D. Zvorykin, et al., Laser Phys. Lett. 13, 125404 (2016)). We treat it as coherent stimulated four-wave mixing process in which two pump KrF laser photons are converted into the coupled pair of resonance IR(828 nm) and VUV (147 nm) photons through 5p5(2P3/2)6p[1/2]0→5p5(2P3/2)6s[3/2]1o and 5p5(2P3/2)6s[3/2]1o→1S0 transitions. We explore the coherent interaction regime which proceeds at a time scale shorter than transverse relaxation time T2. The momentum and energy conservation laws determine the characteristic angle of conical emission. We find that the threshold of this coherent process is determined by the KrF laser pump pulse area.

A New Optical Phenomenon: Exciton Surface Polaritons at Room Temperature

1979 ◽  
Vol 50 (1) ◽  
pp. 139-162 ◽  
Author(s):  
M. R. Philpott ◽  
A. Brillante ◽  
I. R. Pockrand ◽  
J. D. Swalen
Keyword(s):  
Room Temperature ◽  
Surface Polaritons ◽  
Optical Phenomenon

scholarly journals An Optical Phenomenon

Nature ◽  
1909 ◽  
Vol 80 (2068) ◽  
pp. 458-458
Author(s):  
CHARLES E. BENHAM
Keyword(s):  
Optical Phenomenon

scholarly journals An Optical Phenomenon

Nature ◽  
1909 ◽  
Vol 81 (2077) ◽  
pp. 220-220
Author(s):  
L. G. HOXTON
Keyword(s):  
Optical Phenomenon

scholarly journals An Optical Phenomenon

Nature ◽  
1904 ◽  
Vol 70 (1817) ◽  
pp. 396-396
Author(s):  
GEORGE W. WALKER
Keyword(s):  
Optical Phenomenon

'A Singular Optical Phenomenon'

Science ◽  
1884 ◽  
Vol ns-3 (71) ◽  
pp. 704-704
Author(s):  
J. Herschel
Keyword(s):  
Optical Phenomenon

'A Singular Optical Phenomenon'

Science ◽  
1884 ◽  
Vol ns-3 (61) ◽  
pp. 404-404
Author(s):  
Joseph Le Conte
Keyword(s):  
Optical Phenomenon

Application of Moire Methods to the Determination of Transient Stress and Strain Distributions

1962 ◽  
Vol 29 (1) ◽  
pp. 23-29 ◽  
Author(s):  
W. F. Riley ◽  
A. J. Durelli
Keyword(s):  
Strain Distribution ◽  
Stress And Strain ◽  
Two Dimensional ◽  
Distribution Problem ◽  
Principal Stresses ◽  
Transient Stress ◽  
Optical Phenomenon ◽  
Moiré Effect ◽  
Fringe Patterns

When two arrays of lines are superimposed an optical phenomenon known as the moire effect is observed under certain conditions. This moire effect is used by the authors to determine the distribution of transient strains on the surface of two-dimensional bodies. The method can be used to solve completely the strain-distribution problem or it can be used in combination with photoelasticity to separate the principal stresses. The methods used in interpreting the moire fringe patterns and the techniques used to produce the patterns are described in the paper. Two applications are discussed.

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