Morphological investigation of the dynamic structure of the optic cortex in the cat

1967 ◽  
Vol 63 (4) ◽  
pp. 429-432
Author(s):  
E. L. Shul'ga
Keyword(s):  
Dynamic Structure ◽  
Morphological Investigation ◽  
Optic Cortex

The Formation, Structure, Distribution and Frequency of Nuclear Pores

1971 ◽  
Vol 29 ◽  
pp. 518-519
Author(s):  
G. G. Maul
Keyword(s):  
Nuclear Pore Complex ◽  
Nuclear Membrane ◽  
Dynamic Structure ◽  
Nuclear Pore ◽  
Nuclear Pores ◽  
Filter Function ◽  
Etching Technique ◽  
Selective Filter ◽  
Membranous Part

The chromatin of eukaryotic cells is separated from the cytoplasm by a double membrane. One obvious structural specialization of the nuclear membrane is the presence of pores which have been implicated to facilitate the selective nucleocytoplasmic exchange of a variety of large molecules. Thus, the function of nuclear pores has mainly been regarded to be a passive one. Non-membranous diaphragms, radiating fibers, central rings, and other pore-associated structures were thought to play a role in the selective filter function of the nuclear pore complex. Evidence will be presented that suggests that the nuclear pore is a dynamic structure which is non-randomly distributed and can be formed during interphase, and that a close relationship exists between chromatin and the membranous part of the nuclear pore complex.Octagonality of the nuclear pore complex has been confirmed by a variety of techniques. Using the freeze-etching technique, it was possible to show that the membranous part of the pore complex has an eight-sided outline in human melanoma cells in vitro. Fibers which traverse the pore proper at its corners are continuous and indistinguishable from chromatin at the nucleoplasmic side, as seen in conventionally fixed and sectioned material. Chromatin can be seen in octagonal outline if serial sections are analyzed which are parallel but do not include nuclear membranes (Fig. 1). It is concluded that the shape of the pore rim is due to fibrous material traversing the pore, and may not have any functional significance. In many pores one can recognize a central ring with eight fibers radiating to the corners of the pore rim. Such a structural arrangement is also found to connect eight ribosomes at the nuclear membrane.

Application of FRAP and digitized fluorescence microscopy to problems in cell membrane dynamics

1988 ◽  
Vol 46 ◽  
pp. 118-119
Author(s):  
K. Jacobson ◽  
A. Ishihara ◽  
B. Holifield ◽  
F. Zhang
Keyword(s):  
Fluorescence Microscopy ◽  
Cell Biology ◽  
Extended Period ◽  
Dynamic Structure ◽  
Living Cells ◽  
Membrane Dynamics ◽  
Molecular Cell Biology ◽  
Image Averaging ◽  
Single Living Cells ◽  
Single Living

Our laboratory is concerned with understanding the dynamic structure of the plasma membrane with particular reference to the movement of membrane constituents during cell locomotion. In addition to the standard tools of molecular cell biology, we employ both fluorescence recovery after photo- bleaching (FRAP) and digitized fluorescence microscopy (DFM) to investigate individual cells. FRAP allows the measurement of translational mobility of membrane and cytoplasmic molecules in small regions of single, living cells. DFM is really a new form of light microscopy in that the distribution of individual classes of ions, molecules, and macromolecules can be followed in single, living cells. By employing fluorescent antibodies to defined antigens or fluorescent analogs of cellular constituents as well as ultrasensitive, electronic image detectors and video image averaging to improve signal to noise, fluorescent images of living cells can be acquired over an extended period without significant fading and loss of cell viability.

Structure, assembly and interactions of the nuclear lamina and the nuclear pore complex

1992 ◽  
Vol 50 (1) ◽  
pp. 490-491
Author(s):  
N. Panté ◽  
M. Jarnik ◽  
E. Heitlinger ◽  
U. Aebi
Keyword(s):  
Nuclear Pore Complex ◽  
Divalent Cations ◽  
Nuclear Lamina ◽  
Dynamic Structure ◽  
Nucleocytoplasmic Transport ◽  
Nuclear Pore ◽  
Cytoplasmic Filaments ◽  
Radial Spokes ◽  
Nuclear Ring ◽  
Central Plug

The nuclear pore complex (NPC) is a ∼120 MD supramolecular machine implicated in nucleocytoplasmic transport, that is embedded in the double-membraned nuclear envelope (NE). The basic framework of the ∼120 nm diameter NPC consists of a 32 MD cytoplasmic ring, a 66 MD ‘plug-spoke’ assembly, and a 21 MD nuclear ring. The ‘central plug’ seen in en face views of the NPC reveals a rather variable appearance indicating that it is a dynamic structure. Projecting from the cytoplasmic ring are 8 short, twisted filaments (Fig. 1a), whereas the nuclear ring is topped with a ‘fishtrap’ made of 8 thin filaments that join distally to form a fragile, 30-50 nm distal diameter ring centered above the NPC proper (Fig. 1b). While the cytoplasmic filaments are sensitive to proteases, they as well as the nuclear fishtraps are resistant to RNase treatment. Removal of divalent cations destabilizes the distal rings and thereby opens the fishtraps, addition causes them to reform. Protruding from the tips of the radial spokes into perinuclear space are ‘knobs’ that might represent the large lumenal domain of gp210, a membrane-spanning glycoprotein (Fig. 1c) which, in turn, may play a topogenic role in membrane folding and/or act as a membrane-anchoring site for the NPC. The lectin wheat germ agglutinin (WGA) which is known to recognize the ‘nucleoporins’, a family of glycoproteins having O-linked N-acetyl-glucosamine, is found in two locations on the NPC (Fig. 1. d-f): (i) whereas the cytoplasmic filaments appear unlabelled (Fig. 1d&e), WGA-gold labels sites between the central plug and the cytoplasmic ring (Fig. le; i.e., at a radius of 25-35 nm), and (ii) it decorates the distal ring of the nuclear fishtraps (Fig. 1, d&f; arrowheads).

Modulated polarization microscopy displays the dynamics of cytoskeletal structures in living, motile cells

1995 ◽  
Vol 53 ◽  
pp. 902-903
Author(s):  
J. R. Kuhn ◽  
M. Poenie
Keyword(s):  
Mitotic Spindle ◽  
Actin Filaments ◽  
Cell Shape ◽  
Dynamic Structure ◽  
Living Cells ◽  
Cytoskeletal Proteins ◽  
Polarization Microscopy ◽  
Video Enhancement ◽  
Ultrastructural Studies ◽  
Motile Cells

Cell shape and movement are controlled by elements of the cytoskeleton including actin filaments an microtubules. Unfortunately, it is difficult to visualize the cytoskeleton in living cells and hence follow it dynamics. Immunofluorescence and ultrastructural studies of fixed cells while providing clear images of the cytoskeleton, give only a static picture of this dynamic structure. Microinjection of fluorescently Is beled cytoskeletal proteins has proved useful as a way to follow some cytoskeletal events, but long terry studies are generally limited by the bleaching of fluorophores and presence of unassembled monomers.Polarization microscopy has the potential for visualizing the cytoskeleton. Although at present, it ha mainly been used for visualizing the mitotic spindle. Polarization microscopy is attractive in that it pro vides a way to selectively image structures such as cytoskeletal filaments that are birefringent. By combing ing standard polarization microscopy with video enhancement techniques it has been possible to image single filaments. In this case, however, filament intensity depends on the orientation of the polarizer and analyzer with respect to the specimen.

Collection of Ego-Centered Network Data with Computer-Assisted Interviews

Methodology ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Joachim Gerich ◽  
Roland Lehner
Keyword(s):  
Survey Methods ◽  
A Priori ◽  
Dynamic Structure ◽  
Computer Assisted ◽  
Network Data ◽  
Great Effort ◽  
Self Administration ◽  
Face To Face ◽  
Full Network

Although ego-centered network data provide information that is limited in various ways as compared with full network data, an ego-centered design can be used without the need for a priori and researcher-defined network borders. Moreover, ego-centered network data can be obtained with traditional survey methods. However, due to the dynamic structure of the questionnaires involved, a great effort is required on the part of either respondents (with self-administration) or interviewers (with face-to-face interviews). As an alternative, we will show the advantages of using CASI (computer-assisted self-administered interview) methods for the collection of ego-centered network data as applied in a study on the role of social networks in substance use among college students.

STATIC AND DYNAMIC STRUCTURE FACTORS FOR MODELLED NORMAL 4HELIUM

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-215-C6-216
Author(s):  
C. G. Harris ◽  
W.A.B. Evans
Keyword(s):  
Dynamic Structure ◽  
Structure Factors

Features hormonal hemostasis in patients with benign hyper-plastic processes of breasts

2016 ◽  
pp. 72-74 ◽  
Author(s):  
M. Makarenko ◽  
◽  
D. Govsieiev ◽  
O. Gromova ◽  
L. Martynova ◽  
...  
Keyword(s):  
Luteal Phase ◽  
Reproductive Organs ◽  
Breast Diseases ◽  
Hormonal Changes ◽  
Morphological Investigation ◽  
Fibrocystic Disease ◽  
X Ray ◽  
Pelvic Organs ◽  
Hormone Research ◽  
Gynecological Diseases

The objective: to study the incidence of gynecological diseases, clinical and hormonal parameters of the menstrual cycle in patients with benign hyper-plastic processes of breasts. Patients and methods. 65 women with various forms of mastitis were investigated. The following investigations were conducted: mammologistic and gynecological investigation, mommologistic X-ray investigation, ultrasound of breasts and of the pelvic organs, endometrial aspiration biopsy that was followed by cytology; when it was necessary the diagnostic laparoscopy, colposcopy, hysteroscope with curettage and morphological investigation of the endometrium, hormone research and rectal temperature measurements were conducted. Results. The frequency of the benign breast diseases was set: fibrocystic disease of breast – 32 women (49.2±6.20%), fibrous of breast – 16 women (24.6±5.34%), nodular of breasts – 8 women (12.3±4.07%), fibroadenoma – 6 women (9.2±3.59%), nodular disease of breasts on the background of fibroid changes – 3 women (4.6±2.60%). All in all, 96.9±2.14% of the patients had any gynecological diseases. Thus, the average age of the ‘debut’ of mastitis was 31.4±1.09 years; the hyper-plastic processes in the uterus was 35.2±1.17 years. Anovulation was detected in 17 (47.2±8.3%) patients, the lack of the luteal phase (NLF) was detected in 11 (30.6±7.6) patients. Conclusions. Identified hormonal changes are typical for patients with the hyper-plastic processes of the reproductive organs with different localization (breasts, uterus, ovaries). Due to the commonality of the hormone changes in most cases mastitis is combined with the various gynecological diseases (96.9±2.14%). Key words: gynecological pathology, hormonal changes, breast, factors of risk.

Systematics of Hymenophyllum subgenus Mecodium (Hymenophyllaceae) in Taiwan

2019 ◽  
Vol 44 (4) ◽  
pp. 753-767
Author(s):  
Tian-Chuan Hsu ◽  
Yu-Fang Huang ◽  
Yi-Shan Chao
Keyword(s):  
Phylogenetic Relationships ◽  
The Philippines ◽  
Common Element ◽  
Morphological Investigation ◽  
Eastern Asia ◽  
Type Specimens ◽  
The Status ◽  
Molecular Phylogenetic ◽  
A New Species ◽  
Independent Species

Abstract—Hymenophyllum subg. Mecodium, composed of the taxonomically notorious H. polyanthos and approximately 15 other closely related taxa, is a common element of filmy fern communities in the tropical and subtropical moist forests. In Taiwan, although only H. polyanthos and one or two closely related taxa were recognized in recent studies, considerable morphological variation has been observed among populations throughout the island. Thus, we conducted an extensive morphological investigation, as well as a molecular phylogenetic analysis, to clarify the specific diversity and phylogenetic relationships within Hymenophyllum subg. Mecodium in Taiwan. Field and herbaria surveys helped in recognizing five morphs in Taiwan, mainly differentiated by the combination of certain traits, viz., the presence or absence of stipe wings, general frond size and shape, degree of laminar crispation, sori position, and involucre shape. The different morphs had diverse ecological preferences. The phylogenetic tree, inferred from the sequences of the plastid loci rbcL and rps4-trnS, demonstrated that Hymenophyllum subg. Mecodium materials in Taiwan comprise several well-supported lineages, mostly corresponding to the classification based on morphology. Comparing with the protologues and type specimens of 34 related scientific names, the five morphs are herein recognized as five independent species. A new species, Hymenophyllum exquisitum, is described here. Also, the status of H. paniculiflorum is reconfirmed and that of H. fujisanense, H. parallelocarpum, and H. punctisorum reinstated. Only H. exquisitum and H. parallelocarpum are endemic to Taiwan among all the species studied. In addition, the names Hymenophyllum blumeanum, H. integrum, H. microsorum, H. polyanthos, H. tenellum, and H. wrightii are now excluded from the regional flora, and several related taxa from China, Taiwan, and the Philippines are treated as synonyms. This study unravels the deep phylogenetic relationships within Hymenophyllum subg. Mecodium in Taiwan and Eastern Asia.

TO THE PROBLEM OF FORMING THE CATEGORIAL AND CONCEPTUAL APPARATUS OF THE COURSE “HISTORY AND METHODOLOGY OF DESIGN DESIGN”

2020 ◽  
Vol 1 (2) ◽  
pp. 8-15
Author(s):  
N. Aganina ◽  
D. Filonenko D.
Keyword(s):  
Design Theory ◽  
Comparative Method ◽  
Dynamic Structure ◽  
Cultural Analysis ◽  
Problem Statement ◽  
Conceptual Systems ◽  
Concepts And Categories ◽  
Cultural Approach ◽  
Conceptual Apparatus ◽  
Design Culture

The relevance of the study is due to the inevitable obsolescence of fixed concepts and categories of design theory that make up the theoretical foundation of the master's course “History and Methodology of Design”, which is associated with the closeness of the resulting categorical-conceptual systems. The aim of the study is to create a dynamic structure of concepts and design categories that form the categorical-conceptual apparatus of the course. As a methodological basis of the study, a cultural approach is used that allows one to "practically implement a systematic view" on a design that is in the process of constant development and updating. In the course of work, the following research methods are used: problem statement, definition and systematization of concepts and categories, comparative method, historical and cultural analysis. As a result of the study, the authors of the article propose to consider the system of concepts and categories of the course in the form of a “network” formed around the concept of “design culture”, the content of which is revealed using the category of “proektnost”. The proposed structure allows us to preserve the fundamental plurality of interpretations of the concept of design and justify the methodological pluralism of design practice.

THE METADIALOGUE CONCEPT IN ITS LINGUISTIC ASPECT

2019 ◽  
Vol 29 (5) ◽  
pp. 721-726
Author(s):  
Yu.V. Kupriyanova ◽  
I.M. Vasilyanova
Keyword(s):  
Subject Matter ◽  
Dynamic Structure ◽  
Point Of View ◽  
Semantic Relations ◽  
Human Cognition ◽  
Main Research ◽  
Key Points ◽  
Research Findings ◽  
The Subject ◽  
Linguistic Aspect

The article summarizes the key points in the development of the metadialogue phenomenon from a linguistic point of view. Some stages of the development of this concept and the difficulties associated with its structuring are covered. The main research findings of modern foreign and domestic experts on its study are considered. Some characteristics of the subject of the research from the standpoint of various pragmatic installations are given. On the basis of the dynamic structure of the metadialogue development, certain principles of semantic relations connected with the dialectical nature of human cognition are presented. Excursion into the history and evolution of the concept is presented. Several types of formulation of the subject matter are given. In accordance with the goal of speech exposure, internal problems of the development of metadialogue are highlighted and the critical points related to solving these problems are described. The rules of metadialogue flow are explained at the level of steps, the success/failure of which directly affects the final result of communication. The prospects of development of the concept research in accordance with various types of discourse are indicated.

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