The Structure of Trichocysts in Paramecium Caudatum

1972 ◽  
Vol 11 (3) ◽  
pp. 899-929
Author(s):  
L. H. BANNISTER
Keyword(s):  
Amorphous Matrix ◽  
Boundary Surface ◽  
The Body ◽  
Single Type ◽  
Apical Region ◽  
Paramecium Caudatum ◽  
Lower Phase ◽  
Microscopic Appearance ◽  
Outer Sheath ◽  
Crystalline Matrix

The structure of undischarged and discharged trichocysts has been examined in Paramecium caudatum, and their light-microscopic appearance compared with their fine-structural organization. In living specimens undischarged trichocysts appear to be of a single type with a unimodal variation in length about a mean of 3.7 µm. When fixed for electron microscopy or compressed beneath a coverslip many of the trichocysts expand within the cell, giving rise to a variety of different forms of lower phase density. Ultrastructurally the undischarged trichocyst consists of at least 10 different components: these include a mesh-like sheath surrounding the body of the organelle; an inner and an outer sheath enclosing the tip, the inner sheath being made up of 4 spiralling envelopes with a square net substructure, and the outer sheath being formed of a dense amorphous matrix containing longitudinal microtubules and scattered fine filaments; a boundary surface to the outer sheath; a membranous trichocyst sac the apical region of which is surrounded by a cylinder of microtubules joined to each other with dense material; and lastly, the crystalline matrix of the trichocyst body and tip. This crystalline appearance is apparently related to the presence of a loosely interwoven complex of fine filaments which form a highly regular pattern of unit structures repeating at 16-nm intervals. In extended trichocysts the 60-nm banding pattern of the body is also composed of fine filaments arranged in a different, elongated manner in 2 distinct and alternating patterns which are taken to be 2 views of the same structure. Measurements indicate that when trichocysts extend they elongate by a factor of from 6 to 8. It is proposed that the crystalline pattern of the unextended trichocyst body transforms into the extended form by a simple rearrangement of the constituent filaments accompanied by their elongation. Possible models of the undischarged and discharged states of organization are suggested.

scholarly journals CHANGES IN FINE STRUCTURE DURING SILK PROTEIN PRODUCTION IN THE AMPULLATE GLAND OF THE SPIDER ARANEUS SERICATUS

1969 ◽  
Vol 42 (1) ◽  
pp. 284-295 ◽  
Author(s):  
Allen L. Bell ◽  
David B. Peakall
Keyword(s):  
Fine Structure ◽  
Epithelial Cells ◽  
Protein Production ◽  
Distal Portion ◽  
Silk Gland ◽  
The Body ◽  
Single Type ◽  
Secretory Cells ◽  
The Web ◽  
Tunica Intima

The ampullate silk gland of the spider, Araneus sericatus, produces the silk fiber for the scaffolding of the web. The fine structure of the various parts of the gland is described. The distal portion of the duct consist of a tube of epithelial cells which appear to secrete a substance which forms the tunica intima of the duct wall. At the proximal end of the duct there is a region of secretory cells. The epithelium of the sac portion contains five morphologically distinct types of granules. The bulk of the synthesis of silk occurs in the tail of the gland, and in this region only a single type of secretory droplet is seen in the epithelium. Protein synthesis can be stimulated by the injection of 1 mg/kg acetylcholine into the body fluids. 10 min after injection, much of the protein stored in the cytoplasm of the epithelial cells has been secreted into the lumen. 20 min after stimulation, the ergastoplasmic sacs form large whorls in the cytoplasm. Protein, similar in electron-opacity to protein found in the lumen, begins to form in that portion of the cytoplasm which is enclosed by the whorls. The limiting membrane of these droplets is formed by ergastoplasmic membranes which lose their ribosomes. No Golgi material has been found in these cells. Protein appears to be manufactured in the cytoplasm of the tail cells in a form which is ready for secretion.

The Problem on Dynamical Loading of Plane Elastic Regions With Irregular Boundaries

1998 ◽  
Vol 65 (2) ◽  
pp. 476-478
Author(s):  
N. Morozov ◽  
I. Sourovtsova
Keyword(s):  
Wave Propagation ◽  
Boundary Conditions ◽  
The Body ◽  
Single Type ◽  
Edge Condition ◽  
Special Boundary ◽  
Elastic Wedge ◽  
Surface Loading ◽  
Special Surface ◽  
Extension Of Operators

The study of the problem of wave propagation in elastic wedge meets considerable difficulties, which are intensified by the presence of waves of two types that interact with each other through boundary conditions. However, some special surface loading permits separation of the potentials in the boundary conditions, but even in this case the problem cannot be simply reduced to two acoustic ones. The reason for this is that the edge condition cannot be satisfied if the disturbances are limited to a single type (longitudinal or shear). In spite of this the problem, such a special boundary loading nevertheless turns out to be very similar to the acoustic one, which makes it possible to find a closed analytical solution by means of the modified Kostrov method (Kostrov, 1966) and the idea of extension of operators. A similar approach is used for the study of the general problem of loading of the body with several angles.

The development of the tail and the excretory system in the cercaria of Cryptocotyle lingua (Creplin) (Digenea: Heterophyidae from Littorina Littorea (L.))

1977 ◽  
Vol 195 (1121) ◽  
pp. 425-452 ◽  
Keyword(s):  
Secretory Cell ◽  
Proximal Region ◽  
The Body ◽  
Single Type ◽  
Free Swimming ◽  
Wound Area ◽  
Basement Lamina ◽  
Second Intermediate Host ◽  
Separate System ◽  
Vesicular Secretion

The tail of the cercaria of Cryptocotyle lingua develops within the redia (intraredial stage) the process being completed in the molluscan haemocoel (intramolluscan stage). During growth epidermal cell bodies are carried into the proximal region of the tail while the single type of epidermal (secretory) cell body, containing two types of secretions develops later in the same region. The vesicular secretion bodies disperse throughout the outer cytoplasmic epidermis while the clear secretion bodies collect between the inner plasma membrane of the outer cytoplasmic epidermis and the basement lamina, near the tail root, forming the proximal caudal dilation. The epidermal and epidermal (secretory) cell bodies soon degenerate. The longitudinal caudal muscles, at first similar to and continuous with those of the body, gradually develop into the separate system of striated caudal muscles characteristic of the free swimming cercaria. The nuclei of most of the muscle cells degenerate before emer­gence of the cercaria. A secondary excretory pore is formed at the posterior end of the body, in the intraredial cercaria, the caudal excretory vessel and primary pores subsequently degenerating. The tail is shed when the cercaria contacts the fish second intermediate host. The mechanical break at the body–tail junction is caused by the movement of the tail against the resistance of the fixed body. The resulting ‘wound area’ on the body, at first enclosed in the caudal pocket, is soon covered by a layer of outer cytoplasmic epidermis.

scholarly journals Description of Harpagorhynchus golvaneuzeti n. gen. n. sp. (Acanthocephala, Harpagorhynchinae n. sub-fam.) with a review of acanthocephalan parasites of soleid fishes in the Mediterranean Basin

Parasite ◽  
2019 ◽  
Vol 26 ◽  
pp. 15
Author(s):  
Yuriy Kvach ◽  
Isaure de Buron
Keyword(s):  
Mediterranean Basin ◽  
New Genus ◽  
Cerebral Ganglion ◽  
The Body ◽  
Valid Species ◽  
Single Type ◽  
Review Of The Literature ◽  
Sea Of Marmara ◽  
The Mediterranean ◽  
The Mediterranean Basin

A species of acanthocephalan new to science from soleid fishes in the Mediterranean Sea and the Sea of Marmara is described. The new species is characterised by individuals having a club-shaped proboscis armed with 12–13 rows of 6–7 rooted hooks of a single type, a basal cerebral ganglion, and tegumental spines on the anterior two thirds of the body. Males have six cement glands and females show spines around the genital opening. To accommodate this species, a new genus, Harpagorhynchus n. gen., and a new subfamily in Echinorhynchidae, Harpagorhynchinae n. sub-fam., are erected. A critical review of the literature on echinorhynchid species infecting soleid fishes in the Mediterranean basin showed that Solearhynchus soleae (Porta, 1906) should be considered a junior synonym of S. rhytidotes (Monticelli, 1905) and that S. kostylewi (Meyer, 1932) is a valid species. An identification key of acanthocephalans of Mediterranean soleids is provided.

Abstract 297: The Oracle™ Device: A New Snare for Removal of Thrombus

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Richard R Heuser
Keyword(s):  
Randomized Trials ◽  
Mechanical Thrombectomy ◽  
Stroke Care ◽  
Canine Model ◽  
The Body ◽  
Clot Removal ◽  
Outer Sheath ◽  
Minimal Loss ◽  
Thrombus Removal ◽  
Retrieval Device

Stroke is a leading cause of serious disability and death worldwide. Randomized trials have shown benefits of mechanical thrombectomy compared to usual cases with intravenous thombolysis. A simple intuitively obvious device for clot removal would be ideal. To deal with thrombus removal, we introduce the ORACLE™ snare. This snare pictured has the ability to be placed through an .014 system to remove thrombus or other foreign material throughout the body (Figure 1). The Oracle Retrieval Device is composed of three primary parts: an outer sheath tube, a core wire, and 4 capture loops. The 180cm device has loop sizes that range from 2 - 6 millimeters in diameter (Figure 2). There is an ABS plastic operating handle on the proximal end which is used to direct the device as well as to lock the capture loops in the expanded and retracted positions. Utilizing the ORACLE™ snare, we have successfully removed thrombus in a canine model (3 out of 3 removed successfully) and bovine model (2 out of 2 removed successfully) with minimal loss of endothelial cells (Figure 3). With the emergence of dedicated thrombus removal devices for stroke care, more challenges have occurred in treating smaller vessels. Simple intuitively obvious devices available in all carotid and stroke centers as well as centers performing coronary interventions would be ideal. The ORACLE™ may be one approach to remove thrombus and can be placed through .014 compatible catheters.

scholarly journals Applying potential-based panel method for steady flow analysis across a wing with finite span

2019 ◽  
Vol 31 ◽  
pp. 125-136
Author(s):  
Konstantin Metodiev
Keyword(s):  
Steady Flow ◽  
Potential Function ◽  
Collocation Point ◽  
Source Code ◽  
Flow Analysis ◽  
Boundary Surface ◽  
Arbitrary Point ◽  
The Body ◽  
Layer Potential ◽  
Submerged Body

In the paper hereby, an incompressible irrotational steady flow across a submerged body with finite dimensions will be studied. For this purpose, it is necessary to solve Laplace’s differential equation about a potential function in order to obtain the conservative velocity vector field. A general solution to the problem utilizing the Green identity implies the double layer potential function at an arbitrary point not belonging to the boundary surface. The potential is expressed by source/sink and doublet singularities distributed over the body surface and a wake attached to the trailing edge. The wake ensures that the Kutta condition is fulfilled. The submerged body geometry is approximated further by quadrilateral panels in order to compute the surface integrals for each panel exactly. To form a linear non-homogenous algebraic system, it is essentially to compute each panel influence to a collocation point of interest. The obtained coefficient matrix is diagonally dominant. The system is solved iteratively by means of the Gauss-Seidel method. The goal is development of a non-proprietary source code in order to work out a solution to the stated problem. The developed source code is authentic. Auxiliary libraries have not been used. Validation case and numerical results are depicted and discussed in the paper.

scholarly journals X-ray examination methods of veins of the human rectum

2019 ◽  
Vol 18 (2) ◽  
pp. 146-156
Author(s):  
A. N. Russkikh ◽  
A. D. Shabokha
Keyword(s):  
Vascular System ◽  
Rectal Wall ◽  
Structural Characteristics ◽  
The Body ◽  
Portal System ◽  
Single Type ◽  
Contrast Study ◽  
Body Type ◽  
X Ray ◽  
Vein Formation

The aim of this study is to determine the morphometric features of the vessels of the venous system of the rectum of men of different body types using the X-ray method. Materials and methods. To carry out X-ray contrast study of rectum veins in a direct projection of the pelvic organs was performed. Results. As a result of the study, it was established that the developed method of radiological examination of rectum veins, consisting of three consecutive photographs of the stage contrasting of the organ vessels, allows to determine the features of angioarchitectonics and the spatial arrangement of rectal vessels of corpses of men of different body types according to J.M. Tanner without extracting it. The maximum values of the corners of the formation of the second-order portal system of the corpus gynecomorphic somatotype male corpuscles, as well as the minimum values of the angles of vein formation of the first order of their caval system, the constancy of the loose type branching of the portal system parallel to the organ of the vessels, and the frequent occurrence of a single type of branching of the direct vascular organ in the absence of constitutional features branching of the vessels of the cadavers of the rectum of the investigated corpses of men. Conclusion. This finding can be used to assess the effect of venous outflow on the structural characteristics of the vascular system of the rectal wall, depending on the body type of the individual.

scholarly journals THERMAL SHOCK AND DYNAMIC THERMOELASTICITY

2016 ◽  
Vol 11 (1) ◽  
pp. 67-74
Author(s):  
A. Yu. Strigunova ◽  
E. M. Kartashov
Keyword(s):  
Thermal Stress ◽  
Thermal Shock ◽  
Boundary Surface ◽  
Thermal Reaction ◽  
The Body ◽  
Tensor Algebra ◽  
Inertial Effects ◽  
Dynamic Problems ◽  
Heating Rates ◽  
Cooling Mode

This paper considers the problem of thermal shock in the case of a massive body in different conditions of heating and cooling. The most dangerous mode of heating was identified. The influence of inertial effects on the value of emerging thermal stress was investigated. A new equation of compatibility of stress with the inertial effects, which generalizes the known Beltrami-Mitchell relation for quasi-static cases, was obtained by methods of the tensor algebra. The theory of thermal shock in solids was developed in terms of dynamic problems of thermoelasticity in different forms of heat stress: temperature heating; thermal heating; heating medium. Equations for the calculation the jumps in the front of thermoelastic waves were obtained. The most dangerous mode of thermal shock was identified. The effect of relaxation in thermal problems was described in the context of the investigation of thermal stress state of a massive body. It was shown that an increase in relaxation time, i.e. heating rates of the boundary surface of the body, causes a reduction of thermal stress maxima. Original results of the thermal reaction of a solid to cooling were obtained. It was shown that, in comparison with the heating mode, the cooling mode is more devastating, especially for nearsurface layers of solids. The role of the relaxation temperature in the cooling mode was identified. New functional structures were proposed as analytical solutions to the major dynamic problems of thermomechanics on the basis of the use of the Kar functions, which are relatively new.

scholarly journals Molecular and cellular architecture of the larval sensory organ in the cnidarian Nematostella vectensis

2021 ◽  
Author(s):  
Callum Teeling ◽  
Eleanor Gilbert ◽  
Siffreya Pedersen ◽  
Nathan Chrismas ◽  
Vengamanaidu Modepalli
Keyword(s):  
In Situ Hybridisation ◽  
Cell Types ◽  
Molecular Data ◽  
The Body ◽  
Molecular Signature ◽  
Sensory Organ ◽  
Nematostella Vectensis ◽  
Secretory Cells ◽  
Apical Region ◽  
Apical Domain

The apical pole of eumetazoan ciliated larvae acts as a neurosensory structure and is principally composed of sensory-secretory cells. Cnidarians like the sea anemone Nematostella vectensis are the only non-bilaterian group to evolve ciliated larvae with a neural integrated sensory organ that is likely homologous to bilaterians. Here, we uncovered the molecular signature of the larval sensory organ in Nematostella by generating a transcriptome of the apical tissue. We characterised the cellular identity of the apical domain by integrating larval single-cell data with the apical transcriptome and further validated this through in-situ hybridisation. We discovered that the apical domain comprises a minimum of 6 distinct cell types, including apical cells, neurons, peripheral flask-shaped gland/secretory cells, and undifferentiated cells. By profiling the spatial expression of neuronal genes, we showed that the apical region has a unique neuronal signature distinct from the rest of the body. By combining the planula cilia proteome with the apical transcriptome data, we revealed the sheer complexity of the non-motile apical tuft. Overall, we present comprehensive spatial/molecular data on the Nematostella larval sensory organ and open new directions for elucidating the functional role of the apical organ and larval nervous system.

scholarly journals Position of arms as an essential element of the orthodox funeral tradition in Siberia (case study of the Nikolskaya Church cemetery in the city of Novosibirsk)

2021 ◽  
pp. 62-71
Author(s):  
S.V. Gorokhov
Keyword(s):  
Essential Element ◽  
The Body ◽  
Single Type ◽  
Migration Flow ◽  
Her Family ◽  
Funeral Rite ◽  
Specific Position ◽  
Place Of Origin ◽  
The Right ◽  
Over Time

The purpose of this article is to analyze the planigraphic distribution of graves characterized by different posi-tions of arms of the buried people and to identify patterns in their localization. The source base of the research is represented by 384 graves of the Nikolskaya Church necropolis in the town of Krivoshchyokovo. The arms posi-tion has been determined for individuals from 152 graves. The classification criteria for arms positions of the de-ceased have been developed. The analysis of graves enabled us to make a full list of all possible positions of the right or left arm, including the following ones: the arm is stretched along the body (0°), bent at the elbow at ~40°, ~68°, ~90°, ~112°, ~139° or ~166°. In cases when one arm was put on the other one, the relative position of arms (above or below) was recorded. The combination of individual positions of arms and their positioning relatively to each other determines the overall type of arms position. The planigraphic analysis of arms positions of buried people by types has been undertaken. It has been identified that graves with several “plain” and complex types of arms positions are located quite closely to each other. The distribution of graves with certain types of arms posi-tions in the studied part of the necropolis cannot be accidental. Therefore, the established facts of restricted loca-lization of types and complex types of arms positions of the buried people are determined by a cause or a group of causes associated with the historic circumstances of the period when the necropolis was formed. One could assume that the types of arms positions changed over time, following the transformation of beliefs and prescrip-tions of the church in relation to the existing burial tradition. The specific position of arms can be related to the confession of the deceased person and his/her family, as well as traditions of particular regions. In the former case, the position of arms can be characteristic of a specific confession, while in the latter case — of the place of origin of the colonists. Over time, as a result of the long cohabitation and mixing of populations through marriages, the funeral rite should be reduced to a specific single type, however, never reaching an absolute unification due to migration flow of people following different burial traditions. The program of further research into the funeral tradi-tions has been proposed.

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