scholarly journals On the genetics of tetraploid plants in Primula sinensis

1914 ◽  
Vol 87 (597) ◽  
pp. 484-492 ◽  
Keyword(s):  
Somatic Cells ◽  
Cytological Investigation ◽  
Special Significance ◽  
Ordinary Case

The purpose of this paper is to describe certain peculiar results obtained in the genetics of two “giant” races of Primula sinensis . Cytological investigation has shown these giants, unlike the giant races already described,* to be in the tetraploid condition, that is to say, that whereas in ordinary Primulas the chromosomes are x (12) in the gametic and 2 x (24) in the somatic stage, in the tetraploid giants the chromosomes are 2 x (24) in the gametic and, as nearly as can be counted, 4 x (48) in the somatic cells. Nilsson-Ehle and East have shown that factors of similar property may be reduplicated in the same zygote (or gamete), with various peculiar numerical consequences not otherwise intelligible, notably the appearance in certain F 2 -families of such ratios as 15D : 1R, 63D : 1R, and so on, when in the ordinary case 3:1 would be expected. The occurrences to be described in part recall this phenomenon ; but, as will be seen, they are accompanied by others at first sight entirely paradoxical (as, for example, the fact that the ostensible recessive may throw the dominant), and the whole series may be regarded as of special significance in view of the association with the doubled condition of the cell-constituents. Moreover, in the tetraploid Primulas, the reduplication affects not merely the factors for isolated characters, but extends simultaneously to the factors for all the characters so far investigated.

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

3-D examination of the cytoskeletal sheets of mammalian eggs

1992 ◽  
Vol 50 (1) ◽  
pp. 914-915
Author(s):  
Carolyn A. Larabell ◽  
David G. Capco ◽  
G. Ian Gallicano ◽  
Robert W. McGaughey ◽  
Karsten Dierksen ◽  
...  
Keyword(s):  
Actin Filaments ◽  
Somatic Cells ◽  
Freeze Fracture ◽  
Blastocyst Stage ◽  
Cell Cytoplasm ◽  
Planar Structures ◽  
Cytoskeletal Network ◽  
Entire Cell ◽  
Cytoskeletal Networks ◽  
Mammalian Eggs

Mammalian eggs and embryos contain an elaborate cytoskeletal network of “sheets” which are distributed throughout the entire cell cytoplasm. Cytoskeletal sheets are long, planar structures unlike the cytoskeletal networks typical of somatic cells (actin filaments, microtubules, and intermediate filaments), which are filamentous. These sheets are not found in mammalian somatic cells nor are they found in nonmammalian eggs or embryos. Evidence that they are, indeed, cytoskeletal in nature is derived from studies demonstrating that 1) the sheets are retained in the detergent-resistant cytoskeleton fraction; 2) there are no associated membranes (determined by freeze-fracture); and 3) the sheets dissociate into filaments at the blastocyst stage of embryogenesis. Embedment-free sections of hamster eggs viewed at 60 kV show sheets running across the egg cytoplasm (Fig. 1). Although this approach provides excellent global views of the sheets and their reorganization during development, the mechanism of image formation for embedment-free sections does not permit evaluation of the sheets at high resolution.

The Contribution of Pavlov's Typology of CNS Properties to Personality Research

1997 ◽  
Vol 2 (2) ◽  
pp. 125-138 ◽  
Author(s):  
Jan Strelau
Keyword(s):  
Soviet Union ◽  
Former Soviet Union ◽  
Animal Species ◽  
Special Significance ◽  
The West ◽  
Personality Dimensions ◽  
Personality Research ◽  
Personality Theories ◽  
Strength Of Excitation ◽  
Point Of Departure

This paper presents Pavlov's contribution to the development of biological-oriented personality theories. Taking a short description of Pavlov's typology of central nervous system (CNS) properties as a point of departure, it shows how, and to what extent, this typology influenced further research in the former Soviet Union as well as in the West. Of special significance for the development of biologically oriented personality dimensions was the conditioned reflex paradigm introduced by Pavlov for studying individual differences in dogs. This paradigm was used by Russian psychologists in research on types of nervous systems conducted in different animal species as well as for assessing temperament in children and adults. Also, personality psychologists in the West, such as Eysenck, Spence, and Gray, incorporated the CR paradigm into their theories. Among the basic properties of excitation and inhibition on which Pavlov's typology was based, strength of excitation and the basic indicator of this property, protective inhibition, gained the highest popularity in arousaloriented personality theories. Many studies have been conducted in which the Pavlovian constructs of CNS properties have been related to different personality dimensions. In current research the behavioral expressions of the Pavlovian constructs of strength of excitation, strength of inhibition, and mobility of nervous processes as measured by the Pavlovian Temperament Survey (PTS) have been related to over a dozen of personality dimensions, mostly referring to temperament.

The capacity to reprogramme is an intrinsic property of adult somatic cells

2014 ◽  
Author(s):  
Domenico Iuso ◽  
Paola Toschi ◽  
Debora Agata Anzalone ◽  
Marta Czernik ◽  
Grazyna Ewa Ptak ◽  
...  
Keyword(s):  
Somatic Cells ◽  
Intrinsic Property

ABCs of the Revolution

2020 ◽  
Vol 17 (3) ◽  
pp. 278-291
Author(s):  
Egor A. Yesyunin
Keyword(s):  
Civil War ◽  
Second World War ◽  
World War ◽  
Special Significance ◽  
Development History ◽  
The People ◽  
Red Army ◽  
History Of ◽  
Second World ◽  
The Revolution

The article is devoted to the satirical agitation ABCs that appeared during the Civil War, which have never previously been identified by researchers as a separate type of agitation art. The ABCs, which used to have the narrow purpose of teaching children to read and write before, became a form of agitation art in the hands of artists and writers. This was facilitated by the fact that ABCs, in contrast to primers, are less loaded with educational material and, accordingly, they have more space for illustrations. The article presents the development history of the agitation ABCs, focusing in detail on four of them: V.V. Mayakovsky’s “Soviet ABC”, D.S. Moor’s “Red Army Soldier’s ABC”, A.I. Strakhov’s “ABC of the Revolution”, and M.M. Cheremnykh’s “Anti-Religious ABC”. There is also briefly considered “Our ABC”: the “TASS Posters” created by various artists during the Second World War. The article highlights the special significance of V.V. Mayakovsky’s first agitation ABC, which later became a reference point for many artists. The authors of the first satirical ABCs of the Civil War period consciously used the traditional form of popular prints, as well as ditties and sayings, in order to create images close to the people. The article focuses on the iconographic connections between the ABCs and posters in the works of D.S. Moor and M.M. Cheremnykh, who transferred their solutions from the posters to the ABCs.

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