Functional Determination of Rod Free Area of Human Retina

1956 ◽  
Vol 64 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Tadashi Aizawa
Keyword(s):  
Human Retina ◽  
Free Area

The role of opsin expression and apoptosis in determination of cone types in human retina

2004 ◽  
Vol 78 (6) ◽  
pp. 1143-1154 ◽  
Author(s):  
Elisa E. Cornish ◽  
Ming Xiao ◽  
Zhantao Yang ◽  
Jan M. Provis ◽  
Anita E. Hendrickson
Keyword(s):  
Human Retina ◽  
Opsin Expression

A limnological survey of the Ablation Point area, Alexander Island, Antarctica

1977 ◽  
Vol 279 (963) ◽  
pp. 39-54 ◽  
Keyword(s):  
Biological Samples ◽  
New Genera ◽  
Ice Shelf ◽  
Open Sea ◽  
The Antarctic ◽  
Limnological Survey ◽  
Free Area

The ice-free area around Ablation Point (70° 49' S, 68° 25' W) is of particular limnological interest. Numerous ponds and pools lie on coastal moraines and large, permanently ice-covered lakes lie in the valleys. Two of the lakes are unusual in that they are in contact with seawater from George VI Sound which is covered by an ice shelf, 100-500 m thick, and which separates Alexander Island from the Antarctic mainland. Evidence for the existence of a marine biome, 100 km from the open sea, was obtained from one lake. Freshwater biological samples added new genera to Antarctic lists, extended the known range of species, and illustrated the important role of isolation in the determination of antarctic biocoeneses.

Determination of the allowable maximum size of the obstacle while dragging a pipeline

2018 ◽  
Vol 13 (3) ◽  
pp. 42-46
Author(s):  
I.N. Krioni ◽  
A.V. Semenova
Keyword(s):  
Maximum Size ◽  
Moment Equilibrium ◽  
Free Area

In this article, the process of overcoming the stony obstacle while dragging pipeline through the channel is considered. Depending on the size of the duct and the pipeline itself the permissible size of the obstacle that the pipeline can overcome without resting against the upper part of the channel, is considered. To solve this problem, the pipeline is conditionally divided into two sections: the site located up to the obstacle and resting on it, and a free area that is after the obstacle. Directly on the process of dragging through an obstacle are acting the forces and moments which have influence on the pipeline. Starting from the equations of moment equilibrium for different points of the pipeline, and also from the equations of bending beams the value of the obstacle is evaluated.

On the Correspondence between the Spectral Sensitivity Characteristics of Human Eye Retina Photo-Receivers and the Frequencies of the Universal Period-Tripling System

2021 ◽  
pp. 12-19
Author(s):  
Vadim N. Lesnykh ◽  
Valery A. Kolombet ◽  
Alexander V. Elistratov ◽  
Anatoly M. Taranenko ◽  
Simon E. Shnoll
Keyword(s):  
Visual Perception ◽  
Spectral Sensitivity ◽  
Main Parameter ◽  
Great Accuracy ◽  
Human Vision ◽  
Human Retina ◽  
Research Material ◽  
Almost All ◽  
Eye Retina

The article is devoted to the discussion of the evolutionary adjustment of the photodetectors of the human retina to the frequencies of the UPTS (the so-called universal period-tripling system). This is a new scientific direction in the study of complex systems. The article invites lighting engineers who study the issues of visual perception to get acquainted with the phenomenon of UPTS. To date, an experimental research material has been accumulated and sufficient theoretical grounds have been obtained for the formulation of the assumption that the UPTS and its main parameter Тk, m are manifested in almost all time scales. The values of Тk, m are described with great accuracy by means of the empirical Puetz’s formula. In human vision, UPTS manifests itself in the form of nine periods of Тk, m, corresponding to the cases of m = –11, –8, –5, –3, 0, 3, 5, 8, and 11, where the five central ones dominate –5, –3, 0, 3, and 5, corresponding to the rods, as well as the B- and R-cones. Some questions remain about the G-cones and the ipRGC cells that respond to the extreme, “weakened” values of the index m = –11, –8, 8, and 11. The determination of the proposed calculated values of the wavelengths of light corresponding to the maximum spectral sensitivity of retinal photodetectors is important for specialists in the field of visual perception, medicine, optics, as well as for applications in a number of technical applications.

Image Analysis in the Evaluation of the Physical and Physiological Quality of Jiló (Solanum gilo) Seeds during Development

2019 ◽  
pp. 1-10
Author(s):  
Marcus Vinicius Prado Alves ◽  
Édila Vilela De Resende Von Pinho ◽  
Gustavo Costa Prado Alves ◽  
Maria Laene Moreira de Carvalho ◽  
Heloisa Oliveira dos Santos
Keyword(s):  
Image Analysis ◽  
Radiographic Images ◽  
X Ray ◽  
Physiological Quality ◽  
Non Destructive ◽  
Days After Anthesis ◽  
Free Area

Currently, the X-ray image analysis of seeds has proved effective for the evaluation of the physical and physiological quality of the seeds, besides being a non-destructive method. The objective of this work was to evaluate the internal free area of jiló seeds (Solanum gilo) through the analysis of radiographic images and to relate the results with the germination of seeds in different stages of maturation. The seeds were harvested at 35, 40, 45 days after anthesis and 45 days after anthesis with 7 days at rest (45 DAAr). Seeds with free internal area ≤ 10% produced normal seedlings whereas seeds with an average free area above 10% produced abnormal or non-germinated seedlings. Seeds of fruits harvested at 45 DAA and seven days at rest showed a smaller internal free area and a formation of 100% of normal seedlings. The analysis of the radiographic images of jiló seeds allows the measurement of the free internal areas, as well as the determination of the relation between these and the germination.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

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