POLARIZED LIGHT AND BODY TEMPERATURE LEVEL AS ORIENTATION FACTORS IN THE LIGHT REACTIONS OF SOME HYMENOPTEROUS AND LEPIDOPTEROUS LARVAE

1951 ◽  
Vol 29 (6) ◽  
pp. 339-351 ◽  
Author(s):  
W. G. Wellington ◽  
C. R. Sullivan ◽  
G. W. Green
Keyword(s):  
Body Temperature ◽  
Choristoneura Fumiferana ◽  
Polarized Light ◽  
The Other ◽  
Malacosoma Disstria ◽  
The Sun ◽  
Ice Crystal ◽  
Polarization Pattern ◽  
Internal Temperature ◽  
Temperature Level

Larvae of the diprionid sawfly, Neodiprion banksianae Roh., the lasiocampid, Malacosoma disstria Hbn., and the tortricid, Choristoneura fumiferana (Clem.), were used to demonstrate the effects of heat and of plane-polarized light upon the photic orientation of immature insects. Photic orientation was shown to be primarily a result of internal temperature level. When larvae were heated sufficiently, they reversed the sign of their orientation. Larvae of the three species were sensitive to variations in the plane of polarization, and they used the polarization pattern of the sky to varying degrees in their orientation. Neodiprion larvae orientated primarily with reference to the polarization pattern when one was available. Malacosoma larvae and photonegative Choristoneura larvae appeared to orientate with reference to the position of the sun, but rotation of the axis of a "Polaroid" screen through 90° could change the direction of their travel by this amount. On the other hand, photonegative Choristoneura larvae subjected to a 90° shift of the axis continued to orientate with reference to the solar compass position when the sun was visible, even when their actions under the "Polaroid" showed that they could detect changes in polarization. The type of eye structure, the number of pairs of eyes, and the position of these on hypognathous and prognathous heads are considered to have some influence upon the different degrees of efficiency in orientation. Smoke and ice crystal cloud affected the orientation of the "Polaroid" axis that would produce a response, notably when the sun was obscured. Water droplet cloud had little effect, except in a complete overcast, under which polarization was disrupted.

scholarly journals Matched-filter coding of sky polarization results in an internal sun compass in the brain of the desert locust

2020 ◽  
Vol 117 (41) ◽  
pp. 25810-25817
Author(s):  
Frederick Zittrell ◽  
Keram Pfeiffer ◽  
Uwe Homberg
Keyword(s):  
Spatial Orientation ◽  
Matched Filter ◽  
Polarized Light ◽  
Central Complex ◽  
Insect Brain ◽  
The Sun ◽  
Polarization Pattern ◽  
Sun Compass ◽  
Small Spot ◽  
Polarization Compass

Many animals use celestial cues for spatial orientation. These include the sun and, in insects, the polarization pattern of the sky, which depends on the position of the sun. The central complex in the insect brain plays a key role in spatial orientation. In desert locusts, the angle of polarized light in the zenith above the animal and the direction of a simulated sun are represented in a compass-like fashion in the central complex, but how both compasses fit together for a unified representation of external space remained unclear. To address this question, we analyzed the sensitivity of intracellularly recorded central-complex neurons to the angle of polarized light presented from up to 33 positions in the animal’s dorsal visual field and injected Neurobiotin tracer for cell identification. Neurons were polarization sensitive in large parts of the virtual sky that in some cells extended to the horizon in all directions. Neurons, moreover, were tuned to spatial patterns of polarization angles that matched the sky polarization pattern of particular sun positions. The horizontal components of these calculated solar positions were topographically encoded in the protocerebral bridge of the central complex covering 360° of space. This whole-sky polarization compass does not support the earlier reported polarization compass based on stimulation from a small spot above the animal but coincides well with the previously demonstrated direct sun compass based on unpolarized light stimulation. Therefore, direct sunlight and whole-sky polarization complement each other for robust head direction coding in the locust central complex.

Conditional Perception Under Stimulus Ambiguity: Polarization- and Azimuth-Sensitive Neurons in the Locust Brain Are Inhibited by Low Degrees of Polarization

2011 ◽  
Vol 105 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Keram Pfeiffer ◽  
Mario Negrello ◽  
Uwe Homberg
Keyword(s):  
Polarized Light ◽  
The Sun ◽  
Intracellular Recordings ◽  
Polarization Pattern ◽  
Direct Sunlight ◽  
Compass Orientation ◽  
Stimulus Ambiguity ◽  
Low Degrees ◽  
The Brain ◽  
Intensity Contrast

Sensory perception often relies on the integration and matching of multisensory inputs. In the brain of desert locusts, identified neurons that signal the sun's direction relative to the animal's head integrate information about the polarization pattern of the sky with information on the color and intensity contrast of the sky. The cloudless blue sky exhibits a gradient from unpolarized sunlight to strongly polarized light at 90° from the sun. Therefore the percentage of polarized light in the sky is highest at dusk and dawn and lowest when the sun is in the zenith. We investigated the effect of different degrees of polarization on neurons of the anterior optic tubercle of the desert locust through intracellular recordings. Whereas dorsal presentation of strongly polarized light largely excited the neurons, weakly polarized light, i.e., a blend of polarized light of many orientations, led to inhibition. The data suggest that the polarization input to these neurons is inhibited within a radius of 50° around the sun, thereby avoiding conflicting input from the polarization and direct sunlight channels. These properties can be regarded as sensory filters to avoid ambiguous signaling during sky compass orientation.

Body temperature of horses spending time in paddocks in various weather conditions during the summer

2020 ◽  
Vol 16 (1) ◽  
pp. 53-66
Author(s):  
Iwona Janczarek ◽  
Elżbieta Wnuk - Pawlak ◽  
Anna Wiśniewska ◽  
Dominika Dziuban ◽  
Martyna Frątczak ◽  
...  
Keyword(s):  
Body Temperature ◽  
Surface Temperature ◽  
Air Temperature ◽  
Infrared Camera ◽  
Weather Conditions ◽  
The Other ◽  
Body Parts ◽  
Internal Temperature ◽  
Thermal Imagers ◽  
Sunny Weather

The aim of the study was to determine the internal and surface temperature of selected body parts of horses during their stay in paddocks in various weather conditions in the summer. The study was conducted on 10 adult thoroughbred mares. The experiment was carried out on horses spending time in the paddock in four eight-hour stages with differing weather conditions in summer (sunny, cloudy, rainy and windy). Measurements of internal temperature (Veterinär SC 12 veterinary thermometer) and surface temperature of the head, rib area and croup (Thermal Imagers Ti9 FLUKE infrared camera and SmartView 4.1 software) were carried out at rest and again after four and eight hours in the paddock. It was concluded that the time horses spend in the paddock in summer should depend on weather conditions. Many hours spent outside the stable during sunny weather accompanied by high air temperature can contribute to overheating. On the other hand, rain and wind can cause hypothermia. Therefore, it is worth considering leaving horses in the stable or limiting their stay in the paddock to no more than four hours.

scholarly journals Dermoscopic aspect of verrucous epidermal nevi: New findings

2019 ◽  
Author(s):  
ÖMER FARUK ELMAS ◽  
NECMETTİN AKDENİZ
Keyword(s):  
Polarized Light ◽  
Diagnostic Methods ◽  
The Other ◽  
Diagnostic Process ◽  
Fine Scale ◽  
Epidermal Nevus ◽  
Clinical Interpretation ◽  
New Findings ◽  
Clinical Variants ◽  
Histopathological Investigation

Background and Aim: Verrucous epidermal nevi are cutaneous hamartomas having many clinical variants. Dermoscopic features of verrucous epidermal nevus have rarely been investigated. We aimed to identify dermoscopic findings of the entity which will facilitate the diagnostic process by reducing the use of invasive diagnostic methods. Material and Methods: The study included the patients with histopathologically approved verrucous epidermal nevus. Clinical, dermoscopic and histopathological features of the patients were retrospectively reviewed and the findings identified were recorded. Dermoscopic examination was performed with a polarized-light handheld dermoscope with 10-fold magnification. Results: The most common dermoscopic features were thick brown circles, thick brown branched lines and terminal hairs. The most common vessel pattern was dotted vessels. Branched thick brown lines, brown globules, brown dots forming lines, serpiginous brown dots, white and brown exophytic papillary structures, fine scale, thick adherent scale and cerebriform structures were the other findings. Conclusion: We observed many vascular and non-vascular dermoscopic findings which have not been described previously for the entity. Dermoscopic examination of the verrucous epidermal nevi may lead more reliable clinical interpretation and thus it may reduce the need for histopathological investigation. Keywords: dermoscopy, large brown circles, verrucous epidermal nevus

scholarly journals Exploiting the Binocular Head in Polarized Light Microscopy

1994 ◽  
Vol 2 (4) ◽  
pp. 16-16
Author(s):  
Walter C. McCrone
Keyword(s):  
Light Microscopy ◽  
Polarized Light ◽  
Polarized Light Microscopy ◽  
The Other ◽  
Monocular Viewing ◽  
Area Of Interest

Having been brought up on monocular microscopes I find the omnipresent binocular systems a luxury. To support this viewpoint I'd like to suggest some benefits you may not have considered.Because I'm used to monocular viewing I sometimes use two different oculars, say 10X and 25X, in order to scan quickly to find an area of interest and then to examine the detail with higher magnification. Occasionally I use both oculars simultaneously and “concentrate” on either image to the exclusion of the other. A better way is to set the interocular distance at the extreme setting most different from your own interocular distance. By moving your head about a centimeter either way you can use either ocular.

III. Spectroscopic observations of the sun

1867 ◽  
Vol 15 ◽  
pp. 256-258 ◽  
Keyword(s):  
The Other ◽  
The Sun ◽  
Chemical Action ◽  
Spectroscopic Observations ◽  
Gaseous Mass ◽  
Other Hand ◽  
Sun Spots ◽  
Physical Constitution ◽  
Upward Current

The two most recent theories dealing with the physical constitution of the sun are due to M. Faye and to Messrs. De la Rue, Balfour Stewart, and Loewy. The chief point of difference in these two theories is the explanation given by each of the phenomena of sun-spots. Thus, according to M. Faye, the interior of the sun is a nebulous gaseous mass of feeble radiating-power, at a temperature of dissociation; the photosphere is, on the other hand, of a high radiating-power, and at a temperature sufficiently low to permit of chemical action. In a sunspot we see the interior nebulous mass through an opening in the photosphere, caused by an upward current, and the sun-spot is black, by reason of the feeble radiating-power of the nebulous mass.

scholarly journals How dim is dim? Precision of the celestial compass in moonlight and sunlight

2011 ◽  
Vol 366 (1565) ◽  
pp. 697-702 ◽  
Author(s):  
M. Dacke ◽  
M. J. Byrne ◽  
E. Baird ◽  
C. H. Scholtz ◽  
E. J. Warrant
Keyword(s):  
Dung Beetle ◽  
The Sun ◽  
The Moon ◽  
Polarization Pattern ◽  
Animal Group ◽  
Straight Line ◽  
Celestial Orientation ◽  
Polarization Compass ◽  
Celestial Compass ◽  
Diurnal Species

Prominent in the sky, but not visible to humans, is a pattern of polarized skylight formed around both the Sun and the Moon. Dung beetles are, at present, the only animal group known to use the much dimmer polarization pattern formed around the Moon as a compass cue for maintaining travel direction. However, the Moon is not visible every night and the intensity of the celestial polarization pattern gradually declines as the Moon wanes. Therefore, for nocturnal orientation on all moonlit nights, the absolute sensitivity of the dung beetle's polarization detector may limit the precision of this behaviour. To test this, we studied the straight-line foraging behaviour of the nocturnal ball-rolling dung beetle Scarabaeus satyrus to establish when the Moon is too dim—and the polarization pattern too weak—to provide a reliable cue for orientation. Our results show that celestial orientation is as accurate during crescent Moon as it is during full Moon. Moreover, this orientation accuracy is equal to that measured for diurnal species that orient under the 100 million times brighter polarization pattern formed around the Sun. This indicates that, in nocturnal species, the sensitivity of the optical polarization compass can be greatly increased without any loss of precision.

The ecology of the island-lizard Podarcis sicula salfii

1981 ◽  
Vol 2 (3) ◽  
pp. 243-257 ◽  
Author(s):  
P.E. Ouboter
Keyword(s):  
Body Temperature ◽  
Interspecific Competition ◽  
The Sun ◽  
Podarcis Sicula ◽  
Dense Vegetation ◽  
Food Size ◽  
Preferred Body Temperature ◽  
Erica Arborea ◽  
Sufficient Food ◽  
Excursion Time

AbstractIn the summers of 1974 till 1979 microdistribution of Podarcis sicula saffti was examined. Areas without much vegetation and areas with dense vegetation have low densities. Horizontal space, predators, parasites, interspecific competition, shelter and dew appear to be non important factors in the microdistribution of P. s. safii. From 9 a. m. until 6 p. m. temperature in the sun is above PBT (preferred-body-temperature) in all zones. Shade temperature is different from one zone to another. In the most rocky zone without much vegetation, shade is provided by crevices. Shade temperature is under PBT. Food is mainly available outside crevices, in vegetation of Statice sinuatum. Food-size is small, so excursion-time will be long. Lizards are able to collect sufficient food if Statice-plants are close to crevices. The zone with vegetation of Erica arborea, on top of the island, is shaded all day. Shade temperature is under PBT. Only clearings are inhabited by lizards. All other zones have bushes and open areas. During the hot hours bushes provide shade, with shade temperature close to PBT. Food is mainly available in these bushes.

An in vitro Evaluation of Artificial Caries-like Lesions on Restored Overdenture Abutments

1988 ◽  
Vol 67 (3) ◽  
pp. 582-584 ◽  
Author(s):  
P.P. Kambhu ◽  
R.L. Ettinger ◽  
J.S. Wefel
Keyword(s):  
Light Microscopy ◽  
Polarized Light ◽  
Polarized Light Microscopy ◽  
The Other ◽  
Type Ii ◽  
Restorative Materials ◽  
Abutment Teeth ◽  
The Mean ◽  
Materials Used

An acidified dialyzed gelatin gel system was used to determine the caries resistance of a variety of restorative materials used to obturate the canal orifice of overdenture abutment teeth. The restorative materials used were Tytin, Tytin + Copalite, P30 + Scotchbond, Fuji Ionomer-Type II, and Miracle Mix. Polarized light microscopy and microradiography were used to examine the caries-like lesions adjacent to the restorations. The lesions formed in the Fuji Ionomer-Type II and Miracle Mix groups appeared arrested at the wall adjacent to the restoration, and did not penetrate apically down the wall as did those associated with the other restorative materials. The mean depths of lesions adjacent to Fuji Ionomer-Type II and Miracle Mix restorations were significantly less than those of Tytin, Tytin + Copalite, or P30 + Scotchbond.

scholarly journals Pengolahan Limbah Kulit Durian dan Baterai Bekas Menjadi Salah Satu Sumber Energi Listrik yang Ramah Lingkungan

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Muhammad Gifron ◽  
Nelmi Agustina ◽  
Doris Wela
Keyword(s):  
Alternative Energy ◽  
Organic Waste ◽  
Plastic Waste ◽  
The Other ◽  
Basic Material ◽  
The Sun ◽  
Environmental Friendly ◽  
Waste Rubber ◽  
The World ◽  
Parallel Circuit

Abstrak. Seiring dengan bertambahnya jumlah penduduk dunia, selalu diiringi oleh masalah limbah yang berasal dari sampah, baik sampah organik maupun non organik. Berbagai usaha untuk mengatasi masalah limbah tersebut secara berkesinambungan terus dilakukan , baik itu sampah-sampah anorganik seperti, berbahan plastik, karet dan lain-lain. Bisa dimanfaatkan kembali melalui daur ulang menjadi barang-barang kebutuhan harian. Sedangkan untuk sampah organik selain dimanfaatkan untuk pupuk, juga dapat digunakan sebagai bahan dasar pengisi baterai untuk menghasilkan energi alternatif yang ramah lingkungan. Terkhususnya untuk pemanfaatan limbah organik dalam pembuatan baterai telah dilakukan dengan beda potensial tertinggi yang dihasilkan adalah 1,67 volt. Dalam penelitian ini dilakukan modifikasi massa bahan pengisi baterai yang bersumber dari kulit durian yang yang diproses khususnya melalui pengeringan menggunakan oven serta dicampur dengan asam dan ada juga kulit durian yang dijemur selama 7 hari dengan massa kulit durian 3, 5, dan 10. Beda potensial baterai tertinggi yang didapatkan adalah 10 gram yaitu sebesar 1,67 volt. Selanjutnya baterai dengan massa 10 gram difabrikasi dalam jumlah tertentu yang digunakan untuk menyalakan LED. Baterai tersebut dirangkai baik secara seri maupun paralel untuk menghasilkan beda potensial yang bervariasi. Abstract. Along with the growing number of the world populations, there always followed by troubles waste derived from trash, organic waste, and non-organic waste. Many attempts to deal with an organic waste such as plastic waste, rubber, and etc, has been continued, so those waste can be recycled and reused for daily demand. On the other hand, organic waste can be used as fertilizer, and basic material for the battery that results an environmental friendly alternative energy. Especially to utilize the organic waste, the making of battery has been done that yields highest voltage, 1.67 volts. This research aims to modify the mass filler of the battery that obtained from durian skin which is processed by mixing it with acid and drying it using oven, there also other technique by drying the durian skin under the sun for about 7 days which varied masses of 3 gram, 5 gram, and 10 gram. The highest voltage that obtained is 1.67 volt using 10 gram durian skin. Further, the battery with 10 grams durian skin is then fabricated in a specified number to light up the LED. This battery placed either in serial or parallel circuit to obtain varied voltage.

Sign in / Sign up

Export Citation Format

Share Document