scholarly journals Polarized Light and the Orientation of Two Marine Crustacea

1957 ◽  
Vol 34 (3) ◽  
pp. 342-364
Author(s):  
RICHARD BAINBRIDGE ◽  
TALBOT H. WATERMAN
Keyword(s):  
Polarized Light ◽  
Longitudinal Axis ◽  
The Sun ◽  
Visual Contact ◽  
General Direction ◽  
Terrestrial Arthropods ◽  
Linearly Polarized ◽  
Vertical Beam ◽  
Celestial Compass ◽  
The Mean

1. Quantitative experiments are described, designed to test the hypothesis that underwater polarized light is used for orientation by aquatic animals as that of the blue sky is by terrestrial arthropods. 2. Studied in the laboratory the littoral mysid, mysidium gracile, was found capable of orientation relative to the e vector in a vertical beam of linearly polarized light. 3. Statistically significant preference was shown by this animal for aligning its longitudinal axis at right angles to the plane of polarization. 4. A secondary slight preference was shown for swimming parallel with the plane and the degree of random orientation was often high (4% mean). 5. The littoral prawn, Palaemon northropi, when released in quiet water far enough from the bottom and the shore to prevent visual contact, was found to swim on relatively straight horizontal courses for appreciable distances in forty-one out of sixty-one tests. 6. The mean length of these runs was 24.5 m., the maximum 119 m. ; swimming velocities up to about 1 km./hr. were measured. 7. The sun's position seems to be the only directional clue not controlled in these tests, and the general direction of the runs is significantly correlated with the direction of the sun, being at right anglea to it. 8. It is thus concluded that this animar can use the sun, either directly or through the polarization pattern, as a celestial compass.

scholarly journals Problems of Menotactic Orientation According to the Polarized Light of the Sky

1975 ◽  
Vol 30 (1-2) ◽  
pp. 88-90 ◽  
Author(s):  
Kuno Kirschfeld ◽  
M. Lindauer ◽  
H. Martin
Keyword(s):  
Infinite Number ◽  
Polarized Light ◽  
The Sun ◽  
Number Of Solutions ◽  
Special Cases ◽  
Linearly Polarized ◽  
Vector Direction

Abstract It is shown that the knowledge of the E-vector direction of the linearly polarized light at any point of the sky alone is insufficient for the determination of the position of the sun. If the E-vector direction of a second point is not known the knowledge of at least one other parameter is necessary. This parameter might be the height of the sun over the horizon. With the knowledge of the height the infinite number of solutions for the sun’s position becomes reduced to two, or in special cases to one. These cases are derived.

scholarly journals The lizard celestial compass detects linearly polarized light in the blue

2012 ◽  
Vol 215 (18) ◽  
pp. 3200-3206 ◽  
Author(s):  
G. Beltrami ◽  
A. Parretta ◽  
F. Petrucci ◽  
P. Buttini ◽  
C. Bertolucci ◽  
...  
Keyword(s):  
Polarized Light ◽  
Linearly Polarized ◽  
Celestial Compass

Turbidity and the Polarized Light Orientation of the Crustacean Mysidium

1958 ◽  
Vol 35 (3) ◽  
pp. 487-493 ◽  
Author(s):  
RICHARD BAINBRIDGE ◽  
TALBOT H. WATERMAN
Keyword(s):  
Sea Water ◽  
Polarized Light ◽  
Polarization Plane ◽  
Careful Consideration ◽  
Light Illumination ◽  
Turbid Water ◽  
Significant Preference ◽  
Directional Orientation ◽  
Linearly Polarized ◽  
Vertical Beam

1. The influence of the turbidity of the medium on the previously reported directional orientation of the littoral mysid, Mysidium gracile, swimming in a vertical beam of linearly polarized light, has been studied. 2. In carefully clarified sea water the slight preference shown for orientation perpendicular to the polarization plane was not statistically significant. 3. In water made turbid with known amounts of suspended yeast a statistically significant preference for swimming perpendicular to the plane of polarization appeared. 4. This response to the pattern of plarized light illumination appears strontger in highly turbid water than it is in water of moderate turbidity. 5. The mechanism of the observed response seems largely depedent upon discrimination of intensity differences in the light scattered horizontally. 6. These results emphasize the need for careful consideration of the scattering and reflexion artifacts almost invariably present with linearly polarized light.

scholarly journals Effect of Polarized Light Treatment on Milk Production and Milk Somatic Cell Count of Cows

2008 ◽  
Vol 77 (2) ◽  
pp. 225-229 ◽  
Author(s):  
M. Fenyő ◽  
G. Szita ◽  
J. Bartyik ◽  
J. Dóra ◽  
S. Bernáth
Keyword(s):  
Somatic Cell ◽  
Milk Yield ◽  
Polarized Light ◽  
Treated Group ◽  
Control Group ◽  
Cell Counts ◽  
Significant Difference ◽  
Linearly Polarized ◽  
The Mean ◽  
And Control

Treatment with linearly polarized light (LPL) is a widely used and recognized therapeutic method in human medicine for healing wounds, ulcers and a variety of other dermatological problems. Polarized light mobilizes the inadequately functioning defence mechanisms of the human body. The aim of the present experiment was to investigate the effect of LPL treatment on the udder of milking cows. Before the start of treatment, there was no significant difference between cows to be treated with LPL and the control cows in mean somatic cell counts (SCC) of milk samples taken separately by udder quarter and in the mean milk yield. The LPL treatment lasted for 20 min and was performed twice a day over a period of one month. Before treatment, the mean SCC of milk was 3.47 × 105 ± 910 in the group to be treated and 4.07 × 105 ± 920 in the control group. In a six-week period immediately after treatment, the mean SCC of the treated and the control group was 1.32 × 105 ± 825 and 2.63 × 105 ± 825, indicating a significant difference in favour of the treated group. Before the LPL treatment, the milk yield of cows in the group to be treated was 25.77 ± 1.2 kg/ day, while that of the control cows was 27.30 ± 1.4 kg/day. In a six-week period after treatment, the milk yield of cows in the treated and control groups was 28.83 ± 1.5 kg/day and 25.48 ± 1.4 kg/day, respectively. There is a significant difference between these values in favour of the treated group. The results show that a regular LPL treatment of the udder of cows can significantly reduce the SCC of milk and significantly increase the milk yield. The treatment can be applied during lactation without interfering with the milking regime.

scholarly journals The polarized Sun and sky radiometer SSARA: design, calibration, and application for ground-based aerosol remote sensing

2020 ◽  
Vol 13 (1) ◽  
pp. 239-258 ◽  
Author(s):  
Hans Grob ◽  
Claudia Emde ◽  
Matthias Wiegner ◽  
Meinhard Seefeldner ◽  
Linda Forster ◽  
...  
Keyword(s):  
Polarized Light ◽  
Calibration Method ◽  
Saharan Dust ◽  
The Sun ◽  
Dust Layer ◽  
Additional Information ◽  
Clear Sky ◽  
Linearly Polarized ◽  
Aerosol Remote Sensing ◽  
Sky Conditions

Abstract. Recently, polarimetry has been used to enhance classical photometry to infer aerosol optical properties, as polarized radiation contains additional information about the particles. Therefore, we have equipped the Sun–sky automatic radiometer (SSARA) with polarizer filters to measure linearly polarized light at 501.5 nm. We describe an improved radiometric and polarimetric calibration method, which allows us to simultaneously determine the linear polarizers' diattenuation and relative orientation with high accuracy (0.002 and 0.1∘, respectively). Furthermore, we employed a new calibration method for the alt-azimuthal mount capable of correcting the instrument's pointing to within 32 arcmin. So far, this is limited by the accuracy of the Sun tracker. Both these methods are applicable to other Sun and sky radiometers, such as the Cimel CE318-DP instruments used in the AErosol RObotic NETwork (AERONET). During the A-LIFE (Absorbing aerosol layers in a changing climate: aging, LIFEtime and dynamics) field campaign in April 2017, SSARA collected 22 d of data. Here, we present two case studies. The first demonstrates the performance of an aerosol retrieval from SSARA observations under partially cloudy conditions. In the other case, a high aerosol load due to a Saharan dust layer was present during otherwise clear-sky conditions.

Dalnegroite, Tl5–xPb2x(As,Sb)2l–xS34, a new thallium sulphosalt from Lengenbach quarry, Binntal, Switzerland

2009 ◽  
Vol 73 (6) ◽  
pp. 1027-1032 ◽  
Author(s):  
F. Nestola ◽  
A. Guastoni ◽  
L. Bindi ◽  
L. Secco
Keyword(s):  
Polarized Light ◽  
New Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Concentrations ◽  
Reflected Light ◽  
Mohs Hardness ◽  
The Mean ◽  
The University ◽  
Probable Space

AbstractDalnegroite, ideally Tl4Pb2(As12Sb8)Σ20S34, is a new mineral from Lengenbach, Binntal, Switzerland. It occurs as anhedral to subhedral grains up to 200 μm across, closely associated with realgar, pyrite, Sb-rich seligmanite in a gangue of dolomite. Dalnegroite is opaque with a submetallic lustre and shows a brownish-red streak. It is brittle; the Vickers hardness (VHN25) is 87 kg mm-2(range: 69—101) (Mohs hardness ∼3—3½). In reflected light, dalnegroite is highly bireflectant and weakly pleochroic, from white to a slightly greenish-grey. In cross-polarized light, it is highly anisotropic with bluish to green rotation tints and red internal reflections.According to chemical and X-ray diffraction data, dalnegroite appears to be isotypic with chabournéite, Tl5-xPb2x(Sb,As)21-xS34. It is triclinic, probable space groupP1, witha= 16.217(7) Å,b= 42.544(9) Å,c= 8.557(4) Å, α = 95.72(4)°, β = 90.25(4)°, γ = 96.78(4)°,V= 5832(4) Å3,Z= 4.The nine strongest powder-diffraction lines [d(Å) (I/I0) (hkl)] are: 3.927 (100) (10 0); 3.775 (45) (22); 3.685 (45) (60); 3.620 (50) (440); 3.124 (50) (2); 2.929 (60) (42); 2.850 (70) (42); 2.579 (45) (02); 2.097 (60) (024). The mean of 11 electron microprobe analyses gave elemental concentrations as follows: Pb 10.09(1) wt.%, Tl 20.36(1), Sb 23.95(1), As 21.33(8), S 26.16(8), totalling 101.95 wt.%, corresponding to Tl4.15Pb2.03(As11.86Sb8.20)S34. The new mineral is named for Alberto Dal Negro, Professor in Mineralogy and Crystallography at the University of Padova since 1976.

scholarly journals Metasurface of Combined Semicircular Rings with Orthogonal Slit Pairs for Generation of Dual Vector Beams

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1718
Author(s):  
Qian Kong ◽  
Manna Gu ◽  
Xiangyu Zeng ◽  
Rui Sun ◽  
Yuqin Zhang ◽  
...  
Keyword(s):  
Time Domain ◽  
Finite Difference Time Domain ◽  
Polarized Light ◽  
Orientation Angle ◽  
Fdtd Simulation ◽  
Dual Vector ◽  
Vector Beams ◽  
Linearly Polarized ◽  
Potential Applications ◽  
Difference Time

Manipulation of multichannel vector beams (VBs) with metasurfaces is an important topic and holds potential applications in information technology. In this paper, we propose a novel metasurface for the generation of dual VBs, which is composed of orthogonal slit pairs arranged on multiple groups of combined semicircular rings (CSRs). A group of CSRs include a right-shifted set and a left-shifted set of semicircular rings, and each set of semicircular rings has two halves of circles with different radii, sharing the same shifted center. Under the illumination of linearly polarized light, the two shifted sets of semicircular rings generate the two VBs at the shifted center positions on the observation plane. The slit units of each set are designed with independent rotation order and initial orientation angle. By adjusting the linear polarization of illumination, both two VBs with their orders and polarization states are independently controlled simultaneously. The principle and design are demonstrated by the finite-difference time domain (FDTD) simulation. The work is of significance for miniatured devices of VB generators and for related applications.

scholarly journals Formation of half-period surface relief gratings in azobenzene containing polymer films

2020 ◽  
Vol 126 (9) ◽  
Author(s):  
Joachim Jelken ◽  
Carsten Henkel ◽  
Svetlana Santer
Keyword(s):  
Polymer Film ◽  
Polymer Films ◽  
Surface Relief ◽  
Incident Light ◽  
Glassy State ◽  
Polarized Light ◽  
Half Period ◽  
Polarization Distribution ◽  
Linearly Polarized ◽  
Set Up

Abstract We study the peculiar response of photo-sensitive polymer films irradiated with a certain type of interference pattern where one interfering beam is S-polarized, while the second one is P-polarized. The polymer film, although in a glassy state, deforms following the local polarization distribution of the incident light, and a surface relief grating (SRG) appears whose period is half the optical one. All other types of interference patterns result in the matching of both periods. The topographical response is triggered by the alignment of photo-responsive azobenzene containing polymer side chains orthogonal to the local electrical field, resulting in a bulk birefringence grating (BBG). We investigate the process of dual grating formation (SRG and BBG) in a polymer film utilizing a dedicated set-up that combines probe beam diffraction and atomic force microscopy (AFM) measurements, and permits acquiring in situ and in real-time information about changes in local topography and birefringence. We find that the SRG maxima appear at the positions of linearly polarized light (tilted by 45° relative to the grating vector), causing the formation of the half-period topography. This permits to inscribe symmetric and asymmetric topography gratings with sub-wavelength period, while changing only slightly the polarization of one of the interfering beams. We demonstrate an easy generation of sawtooth profiles (blazed gratings) with adjustable shape. With these results, we have taken a significant step in understanding the photo-induced deformation of azo-polymer films.

Fibre bundles in the human extensor carpi ulnaris tendon are arranged in a spiral

2011 ◽  
Vol 37 (6) ◽  
pp. 550-554 ◽  
Author(s):  
N. S. Kalson ◽  
P. S. C. Malone ◽  
R. S. Bradley ◽  
P. J. Withers ◽  
V. C. Lees
Keyword(s):  
Polarized Light ◽  
Clinical Importance ◽  
Longitudinal Axis ◽  
Distal Radioulnar Joint ◽  
Forearm Rotation ◽  
Fibre Bundles ◽  
Extensor Carpi Ulnaris ◽  
Dart Throwing ◽  
Dynamic Stabilizer ◽  
Antagonist Action

The extensor carpi ulnaris musculotendinous unit has important agonist and antagonist action in wrist motion, including the dart-throwing action, and is a dynamic stabilizer of the distal radioulnar joint during forearm rotation. Despite its functional and clinical importance, little is known about its internal structure. Investigation of the ultrastructure of the human extensor carpi ulnaris (ECU) tendon was undertaken using plane polarized light microscopy and microcomputer tomography with 3D reconstruction. The study demonstrates that the tendon comprises fibre bundles (fascicles) approximately 0.1 mm in diameter that are arranged in a gradual spiral. The spiralling fibres make an angle of 8º to the longitudinal axis of the tendon. The spiral structure of the human ECU tendon has important biomechanical implications, allowing fascicular sliding during forearm rotation. The observed features may prevent injury.

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