scholarly journals IV. The electromotive properties of the skin of the common eel

1893 ◽  
Vol 184 ◽  
pp. 335-365 ◽  
Keyword(s):  
Outer Surface ◽  
Complete Removal ◽  
Corrosive Sublimate ◽  
Skin Tissue ◽  
Amphibian Skin ◽  
Du Bois ◽  
Oder Nicht ◽  
The Common ◽  
A Current ◽  
Different Origin

Hermann (1) has investigated the electromotive properties of the skins of Fish. His object in so doing was to attempt to determine, by the employment for experiment of a skin usually credited with being bereft of glands, whether the marked “current of rest” exhibited by the skins of Amphibia is with greater probability to be ascribed to glandular processes in accordance with the opinion of du Bois Reymond (2), or whether the phenomena are not explained with greater simplicity upon the principles of his own ‘Alterations-Theorie.’ Du Bois failed to obtain evidence of a “current of rest” in the four kinds of Fish with which he worked (Eel, Tench, Pike, and Perch), a fact, which taken in conjunction with the absence of “glands” satisfied him that in the richly glandular Amphibian skin the source of the E. M. F. must lie in the secreting structures. Hermann himself, previous to his examination of the skins of Fish, shared to some extent the opinion of du Bois, for in a paper published in 1878 (3), he inclines to the idea, that preparatory processes of glandular origin are the cause of the E. M. F. of the current of rest in the skin of the Frog, but also advances the supposition of a possible contribution from epithelial action at the surface. Finally, as is well known, Hermann demonstrated the presence of an ingoing current of rest in the skins of some ten genera of Fish, but found that its E. M. F. was far less than that exhibited by the Amphibian skin. After noting that substances, the application of which destroys the current of rest in Amphibian skin, cannot be traced microscopically beyond the upper layers of epidermic cells, and recalling the fact that an electromotive excitatory change was demonstrated by Bach and Oehler (4), in the skin of the Frog, after complete removal of the current of rest, by the action of corrosive sublimate applied to the outer surface, Hermann concludes that the E. M. F. of the current of rest, and that of the current of action are of different origin. In speaking of the origin of the current of rest, he makes the following statement, upon the strength of his demonstration of such a current in the “non-glandular” skins of Fish, “dass nicht, oder nicht in erster Linie, die Driisen, sondern die Epithelschicht, der Sitz der elektromotorischen Haut-wirkung ist.” Finally he bases his explanation of the source of the E. M. F. of the current of rest of the skins of both Amphibians and Fish upon the axioms of the “Alterations-Theorie.” According to this hypothesis, the processes of dying or excitation in the continuity of protoplasm cause the more altered parts to be negative electrically to the less altered, so Hermann says “Nun haben wir aber zunächst in alien verhornenden Epithelgebilden eine dem Absterben völlig analoge Alteration, welche von aussen nach innen fortschreitet (und durch den Nachwuchs compensirt wird), nämlich die Verhornung.” Thus in the case of the Amphibian the keratinized superficial cells of the epidermis are supposed to form a demarcation surface whose electrical sign is negative to that of the deeper less altered portions of the skin tissue. Analogous to the “keratin-metamorphose” of protoplasm stands in this connection a “mucin-metamorphose,” and Hermann remarks “Am Aal und an der Trüsche kann man direct sehen, wie die äusseren Zellenden unter Mucinbildung zu Grunde gehen.”

Gill structure in the common limpet Patella vulgata

1978 ◽  
Vol 58 (4) ◽  
pp. 817-823 ◽  
Author(s):  
M. A. Nuwayhid ◽  
P. Spencer Davies ◽  
H. Y. Elder
Keyword(s):  
Epithelial Cells ◽  
Outer Surface ◽  
Smooth Endoplasmic Reticulum ◽  
Single Layer ◽  
Muscle Fibres ◽  
Nervous Control ◽  
Gill Structure ◽  
Membrane Bound ◽  
The Common ◽  
A Current

The gills of Patella consist of a row of triangular shaped leaflets suspended from the roof of the pallial groove. The surface of each gill is thrown into a series of transverse furrows. Tufts of cilia are irregularly distributed over the surface and generate a current of water which flows in the opposite direction to the flow of blood within. The central part of the gill comprises a large haemocoelic space traversed by trabeculae which contain muscle fibres and suggesting that the flow of blood through the gill may be under nervous control. A blood channel runs around the periphery of the gill.The epithelial layer bounding the blood space comprises a single layer of columnar epithelial cells. The outer surface is protected by a structured mucopolysaccharide glycocalyx held in place by a dense mat of microvilli. The cells contain clearly defined mitochondria, Golgi complex, lysosomes, rough and smooth endoplasmic reticulum. In addition, the non-ciliated cells are characterized by a layer of membrane-bound granules, of unknown function, in the apical cytoplasm.Phagocytes are frequently found associated with the basement membrane. They contain large membrane-bound granules and appear to move outwards between the epithelial cells to expel the granules at the outer surface of the gill. It is possible that the gill has an excretory as well as respiratory role in the physiology of the animal.

Amorphous Polymeric Dithiazine apDTZ Solid Fouling: Critical Review, Analysis and Solution of an Ongoing Challenge in Triazine-Based Hydrogen Sulphide Mitigation

2021 ◽  
Author(s):  
Grahame Taylor ◽  
Jonathan Wylde ◽  
Walter Samaniego ◽  
Ken Sorbie
Keyword(s):  
Hydrogen Sulphide ◽  
Reaction Pathway ◽  
Theoretical Calculations ◽  
Mechanism Of Formation ◽  
Review Analysis ◽  
Operational Problem ◽  
Depth Study ◽  
The Common ◽  
By Products ◽  
A Current

Abstract Despite attempts to inhibit or avoid the formation of fouling deposits (polymeric amorphous dithiazine or apDTZ for short) from the use of MEA triazine, this remains a major operational problem and limits the use of this most popular and ubiquitous hydrogen sulphide (H2S) scavenger. This paper (a) reviews and summarizes previous work, (b) provides fresh insights into the reaction product and mechanism of formation, (c) proposes an effective method of removal, and (d) proposes some mechanisms of apDTZ digestion. The mechanism of apDTZ formation is discussed and reasoning is provided from a variety of perspectives as to the mechanism of MEA-triazine reaction with H2S. These include basicity and nucleophilic substitution considerations, steric properties and theoretical calculations for electron density. Novel procedures to chemically react with and destroy this solid fouling are presented with an in-depth study and experimental verification of the underlying chemistry of this digestion process. A review of agents to chemically destroy apDTZ is undertaken and a very effective solution has been found in peroxyacetic acid, which is much more powerful and effective than previously suggested peroxides. The structure of amorphous polymeric dithiazine is emphasized and the reason why this fouling cannot be 1,3,5-trithiane is stressed. This work therefore overcomes a current industry misconception by providing insight on two major paradoxes in the reaction pathway; namely i) why the thiadiazine reaction product from tris hydroxyethyl triazine (MEA triazine) is never observed and ii) why does the dithiazine in all cases never progress to the trithiane (3rd sulphur molecule substitution)? The latter issue is probably the biggest misconception in the industry and literature regarding triazine and H2S reactions. Many reasons for this are put forward and the common misconception of "overspent" triazine is refuted. A very effective chemical reaction that results in soluble by-products, counteracting the problems produced by this intractable polymer is found and their composition is proposed and experimentally verified.

scholarly journals Doing nothing does something: Embodiment and data in the COVID-19 pandemic

2020 ◽  
Vol 7 (1) ◽  
pp. 205395172093393
Author(s):  
Mickey Vallee
Keyword(s):  
Public Health ◽  
Media Studies ◽  
Common Good ◽  
Current Data ◽  
The Body ◽  
Health Crisis ◽  
Critical Data ◽  
The Social ◽  
The Common ◽  
A Current

The COVID-19 pandemic redefines how we think about the body, physiologically and socially. But what does it mean to have and to be a body in the COVID-19 pandemic? The COVID-19 pandemic offers data scholars the unique opportunity, and perhaps obligation, to revisit and reinvent the fundamental concepts of our mediated experiences. The article critiques the data double, a longstanding concept in critical data and media studies, as incompatible with the current public health and social distancing imperative. The data double, instead, is now the presupposition of a new data entity, which will emerge out of a current data shimmer: a long-sustaining transition that blurs the older boundaries of bodies and the social, and establishes new ethical boundaries around the (in)activity and (im)mobility of doing nothing to do something. The data double faces a unique dynamic in the COVID-19 pandemic between boredom and exhaustion. Following the currently simple rule to stay home presents data scholars the opportunity to revisit the meaning of data as something given, a shimmering embodied relationship with data that contributes to the common good in a global health crisis.

scholarly journals Turn-Taking in Colloquial Indonesian

2017 ◽  
Vol 12 (4) ◽  
pp. 238
Author(s):  
Agus Subiyanto Subiyanto
Keyword(s):  
Repair Mechanism ◽  
Recording Technique ◽  
Informal Conversation ◽  
Turn Taking ◽  
The Common ◽  
Current Speaker ◽  
A Current ◽  
Participatory Observation

Participants in a conversation follow certain basic rules in obtaining turns. Some questions addressed in this paper are, firstly, how turns are allocated in Indonesian conversation. Secondly, what  are the signals given by a current speaker willing to yield to a next speaker (i.e. turn-yielding signals). Thirdly, what repair mechanism is  employed by the participants when the turn-taking procedures are broken. The data used in this study were taken from an informal conversation of four Indonesians from Jakarta. The data were collected by using a non-participatory observation with a recording technique. The analysis shows that the turn-taking system in the Indonesian language confirms the model of turn-taking system developed by Sacks et al (1974), covering the occurrence and the recurrence of speaker change, the overwhelming tendency for one party to talk at a time,the common occurrences of more than one speaker at a time, and the common switches of speakers with no gapsand no overlaps.

The opercular bond in the egg-shell of the monogenean Entobdella soleae, a platyhelminth skin parasite of the common sole (Solea solea)

Parasitology ◽  
1999 ◽  
Vol 118 (4) ◽  
pp. 433-438
Author(s):  
G. C. KEARN ◽  
R. EVANS-GOWING ◽  
T. TAPPENDEN
Keyword(s):  
Embryonic Development ◽  
Outer Surface ◽  
Outer Region ◽  
Cement Layer ◽  
Solea Solea ◽  
Inner Surface ◽  
The Common ◽  
Egg Shell ◽  
Common Sole

The monogenean (platyhelminth) skin parasite Entobdella soleae from the common sole (Solea solea) lays tetrahedral eggs. One of the 4 corners of the tetrahedron is a detachable operculum which is bonded to the rest of the egg-shell by cement. Most of this cement layer, beginning at the inner surface of the shell and running through almost to the outer surface (a distance of about 2 μm), is more or less uniform in thickness (30–38 nm), or tapers slightly. About 345 nm from the outer surface the cement layer narrows abruptly to about 10 nm. The cement is exposed on the inner surface of the shell, but in most eggs a layer of shell about 10 nm thick covers the narrow outer region of the cement layer. When experimentally perforated eggs were incubated with trypsin, the wide inner layer of cement was digested, but the narrow outer region initially remained intact. These observations are discussed in relation to the following (1) survival of the eggs during embryonic development, (2) hatching, (3) the ‘hinge’ often connecting the operculum to the empty egg-shell, (4) the rapid hatching that occurs in some other monogeneans.

scholarly journals II. Note on the electromotive properties of muscle

1877 ◽  
Vol 25 (171-178) ◽  
pp. 435-439 ◽  
Keyword(s):  
Original Work ◽  
Transverse Section ◽  
Longitudinal Section ◽  
Great Work ◽  
Circular Area ◽  
Du Bois ◽  
Nearest Point ◽  
Equal Distance ◽  
The Law ◽  
A Current

In the great work entitled ‘Untersuchungen über thierische Electricitat,’ of which the first volume was published by Professor du Bois-Reymond in 1848, the author promulgated, as the result of the remarkable investigations undertaken by him during the previous six years, certain propositions relating to the electromotive properties of muscle. These propositions (which in the original work were printed in large type) were termed by the author collectively the “Law of the musclecurrent.” They have been accepted by all later observers as fundamental truths. They are as follows :— “ The Law of the Muscle-current . I. Active arrangements . A. Strong Currents . If any point of the natural or artificial longitudinal section of a muscle is brought into connexion with any point of the natural or artificial transverse section of the same muscle, so that no tension is thereby produced, a current is indicated by any galvanoscopic apparatus introduced into the inactive conducting circuit, of which the direction in the circuit is from the longitudinal to the transverse section.—B. Weak Currents . a. Currents of the transverse section . Further, if any point of a natural or artificial transverse section of a muscle is connected in the manner already described with another point of the same transverse section, or with a point of another natural or artificial transverse section of the same muscle, which we will regard as a cylinder, and if the points are at unequal distances from the centre of the circular area of the transverse section, the galvanoscopic apparatus again indicates a current, though much weaker than the previous one, of which the direction is from the point more distant from the centre to the nearest point.—b. Currents of the longitudinal section . Thirdly, if a point of the natural or artificial longitudinal section, lying nearer to the geometrically central transverse section of the cylinder formed by the muscle, is brought in the same way into relation with a point of the natural or artificial longitudinal section of the same muscle more distant from the central transverse section, the galvanoscopic apparatus again indicates a current, which is, however, much weaker than that between any point of the natural or artificial longitudinal and any point on the transverse section, but is equal in strength to that between different points on one or two natural or artificial transverse sections. Its direction in the circuit is from the point lying nearer to the middle transverse section to that further removed from it.—II. Inactive arrangements . The galvanoscopic apparatus, on the contrary, remains at rest when two points in one or two natural or artificial transverse sections connected through the inactive conducting circuit are at an equal distance from the centre; or when one or two points in the natural or artificial longitudinal section so connected are at an equal distance from the central transverse section.

scholarly journals 4th International Academic Conference “Liturgical Practices and Hieratic Arts Nowadays: Prospects for the Development of Research Area” (Krasnodar, November 9–12, 2020)

2021 ◽  
pp. 141-145
Author(s):  
Svetlana Hvatova
Keyword(s):  
Human Life ◽  
Religious Practice ◽  
Research Area ◽  
Religious Practices ◽  
Current State ◽  
Academic Conference ◽  
New Information ◽  
The Common ◽  
A Current

The paper analyses the findings of the 4th International Academic Conference. The academics reported new information on the current state of religious practices of different faith communities, as well as identified the hieratic signs in the context of secular art. The reporting researchers also explored the state of the liturgical canon in a current religious practice and reviewed the sacral aspect of human life in the context of traditional religious practices. The scholars also discussed the role of hieratic art in community life, its educational and enlightening capacity, and the modern forms of representation of the sacred. For the fourth time, the common subject of the study brings together art historians, historians, culture researchers, educators, psychologists, theologians, philosophers, and a number of persons involved in spiritual enlightenment and education.

scholarly journals ATTEMPT TO IMPROVE THE OPERATING AND TECHNOLOGICAL PROPERTIES OF THE COMBINED GRAIN WASHING MACHINE

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
L. Soldatenko ◽  
A. Shipko ◽  
I. Shipko
Keyword(s):  
Water Consumption ◽  
Opposite Direction ◽  
Outer Surface ◽  
Complete Removal ◽  
Control Device ◽  
Lower Edge ◽  
Mineral Particles ◽  
Washing Machines ◽  
Vertical Speed ◽  
Light Impurities

Washing machines are used in the production lines of grain cleaning departments of flour mills for thorough cleaning of the grain surface, in particular, its grooves from the remnants of organic and mineral dust, microorganisms and mold. In addition, the grain mass during washing is cleaned of hydrodynamically light and heavy impurities - chaff, seeds of waste plants, straw fragments, mineral particles in the form of sand, small stones, lumps of earth, as well as spores and wormwood seeds. At the same time, foreign odors of grain disappear.Experience in the operation of Ж9-БМА machines shows that along with many advantages, they have some disadvantages. In particular, the productivity of the machine 10 t / h does not correspond to the productivity of the conjugated technological equipment of the production line, and the specific water consumption for washing grain is 1.8… 2.0 l / kg, which is too much in modern conditions of acute shortage of drinking water. Enterprises to abandon the use of washing machines. In addition, certain problems and inconveniences are caused by the design of the sieve shell of the impression column. Stamped sieves with scaly asymmetric holes have a low coefficient of living cross section, which complicates the process of dehydration of washed grain, quickly corrode and rub, require special attention during installation or replacement. Therefore, an attempt is made to eliminate these shortcomings.In particular, the reduction of water consumption is achieved due to the elimination of the grain hydraulic conveyor during its transfer from the washing bath to the pressure column. For this purpose, a device for mechanical overloading of grain by a rotary bucket device located within the alloy chamber is used. At the same time, attention was paid to the separation of light organic impurities from the grain. This decision needs further explanation.The functional diagram shows that the initial grain mixture enters the receiving device, which feeds it with a minimum vertical speed into the ascending water streams created by the screws of two grain augers rotating with the same frequency in the opposite direction. The augers pick up the grain and, keeping it afloat in a suspended state, mix it with the water of the washing bath. At the same time the grain is washed and particles are separated from it, which differ from it in terms of density: mineral impurities begin to sink, fall down and through the longitudinal slit in the auger trough fall into the area of the auger for mineral impurities. This auger transports the "stones" in the opposite direction to the funnel with the ejector of the hydrotransporter of mineral particles. Light impurities, during the transportation of grain by grain augers, float to the surface of the water, the level of which in the washing bath is maintained up to the axis of the augers. Together with grain and water, these impurities are pushed out of the bath into the alloy chamber.In the chamber, in the transverse direction, a pipe with a longitudinal absorption slot is installed, the lower edge of which is immersed in water so that the upper layer of water merges into this slot together with light impurities that have surfaced in the washing bath. The amount of water that fuses light impurities can be adjusted by the depth of immersion in water of the lower edge of the absorption hole. To do this, the pipe is rotated relative to its axis with a special handle with a clamp and a pointing scale. One end of the pipe is closed by a plug, and the other passes through a hole in the wall and drains the water with light impurities into the sink sump. The described device provides almost complete removal of light impurities and minimal consumption of floating water. This solution is in the invention according to the copyright certificate 701708404, developed by specialists of the department TOZV. In addition, certain problems and inconveniences are caused by the design of the sieve shell of the squeezing column. Dirt particles tend to stick to the outer surface of the sieve cylinder and block its holes. This can slow down and even stop the separation of water by centrifugation. Therefore, the upper outer surface of the cylinder is washed with water, which in automatic mode is periodically fed to the sieve by the control device and the solenoid valve. It also saves water.

On the nature of roots

2020 ◽  
Vol 2 (1) ◽  
pp. 56-83
Author(s):  
Phoevos Panagiotidis
Keyword(s):  
Final Section ◽  
Native Speakers ◽  
Semantic Content ◽  
Current Understanding ◽  
Common Denominator ◽  
Logical Conclusion ◽  
The Common ◽  
Grammatical Structures ◽  
A Current ◽  
Late Insertion

Abstract This paper offers a review of a current understanding of the content and the form of linguistic roots. It first updates and buttresses the case against semantic content of uncategorised roots and for Late Insertion of roots; then it investigates how native speakers identify roots. More specifically, the idea that roots may be polysemous or may encode the shadow of a denotation, namely the common denominator of the denotations of words derived from it, is refuted on the basis of conceptual and empirical arguments from a number of languages. Subsequently, the existence of a spectrum of content to which roots belong, with roots ranging from contentless to semantically specific and concrete, is also shown to be illusory, and to result from the actual productivity, hence diversity, of the words derived from it. Arguments for Late Insertion of roots are then reviewed and updated, divorcing roots from the forms that realise them. These arguments are systematically combined with the semantic contentlessness of roots in support of Acquaviva’s analysis of them as abstract indices, i.e. as the syntax-internal criteria of lexical identity. This account is taken to its logical conclusion in the final section: if roots are indeed abstract indices, then they cannot be identified either by the semantic content they realise within grammatical structures or by their forms. An account is therefore advanced according to which roots are identified just once by native speakers over their lexicon at a given moment and on the basis of three heuristic principles: one form-based, one based on the feature content and the exponence of the structures in which roots are embedded, and one taking care of root suppletion.

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