scholarly journals The role of sleep in forming a memory representation of a two-dimensional space

Hippocampus ◽  
2013 ◽  
Vol 23 (12) ◽  
pp. 1189-1197 ◽  
Author(s):  
Marc N. Coutanche ◽  
Carol A. Gianessi ◽  
Avi J.H. Chanales ◽  
Kate W. Willison ◽  
Sharon L. Thompson-Schill
Author(s):  
K. Stróż

AbstractThe plane groups are rarely discussed in the crystallography courses and the didactic role of the plane groups for teaching symmetry is rather underestimated. Most crystallographic concepts known from 3-dimensional space group descriptions concern also these 2-dimensional groups and can be easier illustrated. Symmetry of atomic layers as well as symmetry of mosaics, lattice designs, symmetry of electron diffraction patterns or any pattern with two-dimensional periodicity can be characterised on a unique basis. Such a pattern can be generated by decorating the points of a crystallographic orbit by different graphical objects. The orbits are visualised as “crystallographic mosaics” (by connection of the closest points of the orbit), they can be characterised by Shubnikov or Laves nets and there always exists a number (circle packing density) that is related to a given orbit. The paper and a didactic computer program presented in it give some ideas and framework for the plane symmetry experiments: from finding the isometries on the generated patterns to identifying the non-characteristic orbits. It is also shown that the contour map of a circle packing density is a good frame for locating symmetry elements, asymmetric units or points with higher plane symmetry into a unit cell. The applied complex approach to the orbit characterisation will narrow the gap existing between concepts used by practising and theoretical crystallographers and mathematicians interested in tessellations.


1994 ◽  
Vol 09 (09) ◽  
pp. 1555-1568 ◽  
Author(s):  
DMITRIJ P. SOROKIN ◽  
DMITRIJ V. VOLKOV

Drawing an analogy with the Dirac theory of fermions interacting with electromagnetic and gravitational field we write down supersymmetric equations of motion and construct a superfield action for particles with spin [Formula: see text] and [Formula: see text] (quartions), where the role of quartion momentum in effective (2+1)-dimensional space–time is played by an Abelian gauge superfield propagating in a basic two-dimensional Grassmann-odd space with a cosmological constant showing itself as the quartion mass. So, the (0|2) (0 even and 2 odd) dimensional model of quartions interacting with the gauge and gravitational field manifests itself as an effective (2 + 1)-dimensional supersymmetric theory.


2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Gergana Tabakova ◽  

I offer a glimpse at the essence of the visual arts, which is related to the conceptual and the visual constructions through which the image is constructed. Although very different from painting, cinema, as a visual art, is influenced by it at a depth that is hard to imagine. I am taking into account the views of Sergei Eisenstein – one of the proponents of the formal theory of cinema, displayed in his theoretical works, as well as several of his films. Changes in the visual arts that result from the advent of photography give new meaning and role of painting. Artists occupied in painting are beginning to look for new ways to solve the problem of three-dimensional space in a two-dimensional surface. In the time that cinema develops own language, it sets to itself similar tasks. At that moment, cinema turns to the familiar visual-artistic experience and its forms in order to construct its own imaginative language. Cinema, like painting, gives us the joy of looking at the form in which the correlation of the elements is sensed. Accordingly, in order to bring pleasure and meaning, this form is created in constructions that we know from the field of painting. Editing, the basis of cinematic language, is built by putting together frames that serve as building blocks of the film. In this capacity they are of utmost importance. It is frame’s compositional organization, which at first takes place in a two-dimensional space as in picture that plays a major role in the approach to the editing. The composition of the frame which is the core of the editing process is built in the parameters of the main points through which the composition in painting can be built – rhythm, dynamics, statics, symmetry, asymmetry, analysis and synthesis of form, and at a later stage of the development of cinema – even color. The visual arts are based on similar structures and ways of building the form though they do it through different languages. There are unifying principles that define the world of images. Whether they are moving or static, their construction is often done on the basis of similar intentions and through similar instruments. Knowing them, understanding them, is a tool for creating quality images.


Author(s):  
P. M. Pustovoit ◽  
E. G. Yashina ◽  
K. A. Pshenichnyi ◽  
S. V. Grigoriev

Author(s):  
Russell J. Dalton

This chapter uses the cleavage positions of Candidates to the European Parliament (CEPs) to as representative of their parties’ political positions. Three surveys of CEPs track the evolution of party supply in European party systems. In 1979 parties were primarily aligned along a Left–Right economic cleavage. Gradually new left and Green parties began to compete in elections and crystallized and represented liberal cultural policies. In recent decades new far-right parties arose to represent culturally conservative positions. The cross-cutting cultural cleavage has also prompted many of the established parties to alter their policy positions. In most multiparty systems, political parties now compete in a fully populated two-dimensional space. This increases the supply of policy choices for the voters. The analyses are based on the Candidates to the European Parliament Studies in 1979, 1994, and 2009.


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