XIII. Electro-physiological researches.—third memoir. On Induced contractions

1845 ◽  
Vol 135 ◽  
pp. 303-317 ◽  
Keyword(s):  
Electric Current ◽  
Electric Discharge ◽  
The Other ◽  
Spinal Marrow ◽  
In The Beginning ◽  
Saline Solutions ◽  
A Current ◽  
Made In

The term Induced contractions was applied in England to a physiological fact discovered by myself, and described in the tenth chapter of my treatise on the Electro-physiological Phenomena of Animals. I shall henceforth adopt this denomination, since it has the advantage of expressing the phenomenon with brevity, and, to a certain degree, its nature. I will begin by explaining, in a few words, in what this fact consists, together with the principal researches which I made in the commencement for the purpose of discovering its laws. Having prepared a galvanoscopic frog, I laid its nerve upon one or both the thighs of a frog prepared in the ordinary manner; this done, on applying the poles of a pile upon the lumbar plexuses of the frog, at the same time that the muscles of the thighs were contracted, contractions were excited in the galvanoscopic leg, the nerve of which reposed upon the thigh of the other frog. I discovered the same fact, placing the nerve of the galvanoscopic frog upon a muscle of the thigh of a rabbit, and exciting the muscle to contraction by means of a current, which traverses its nerve. I have even seen contractions of the galvanoscopic frog occur without applying the electric current for the purpose of contracting the muscle which ought to induce the contractions, adopting for this purpose any other stimulus to the lumbar plexuses or to the spinal marrow. I finally tried these experiments, introducing between the nerve of the galvanoscopic frog and the inducing muscular surface very fine laminæ of different substances. A leaf of gold and a very fine non-conducting stratum of mica or of glazed paper being interposed prevented the phenomenon, that is to say, the induced contractions in the galvanoscopic frog failed to appear, whilst a stratum of fine paper soaked in water did not interrupt the induced contraction. From the whole of these facts I was led to conclude,—1st, that the contraction induced in the galvanoscopic frog could not be attributed to the effect of derived currents; 2nd, that it should rather be considered the effect of an electric discharge taking place during the contraction of a muscle. For the sake of supporting this explanation of the induced contractions by facts, I instituted a great number of experiments which are described in the tenth chapter above referred to. With this view I composed a pile of entire frogs, and closed the circuit with the two extremities of the galvanometer. Allowing the needle to become stationary, I touched specially the nerves of the frogs composing the pile with a solution of potassa, by which means contractions were excited in these frogs. Operating in this manner, I have often remarked the deflection of the needle to be increased by a few degrees, after which the needle retrograded. When the frogs were touched several times with the potassa, or were very much weakened, so that touching them again with the alkali no longer produced contractions, it has, in most cases, occurred that there was no sign of increased deflection in the needle of the galvanometer. Finally, bathing the nerves of frogs arranged in piles with acid or saline solutions, the deflection, far from increasing, rapidly diminished, at least in the beginning.

Crowdfunding research agenda: Semantic analysis of the media and geography of investments

2019 ◽  
pp. 1930001
Author(s):  
Israel José dos Santos Felipe ◽  
Wesley Mendes-Da-Silva ◽  
Cristiane Chaves Gattaz
Keyword(s):  
Mass Media ◽  
Research Agenda ◽  
Semantic Analysis ◽  
The Other ◽  
Financial Returns ◽  
Regional Characteristics ◽  
Present Information ◽  
The Media ◽  
A Current ◽  
Made In

This paper proposes a current research agenda on crowdfunding from two different perspectives, mass media and geography. It is believed that these two elements must exert some kind of influence on the dynamics of the investments made in that market. Semantic analysis of mass news can be a useful tool for investors to assess their exposure to risk as well as help predict financial returns. Geography, on the other hand, can be used on the origin of the capital contributions and, therefore, present information on the location and regional characteristics of the investors.

scholarly journals The electrical reactions of certain bacteria, and an application in the detection of tubercle bacilli in urine by means of an electric current

1909 ◽  
Vol 81 (548) ◽  
pp. 314-322 ◽  
Keyword(s):  
Electric Current ◽  
Platinum Foil ◽  
Electrical Connection ◽  
Glass Cell ◽  
Pathogenic Organisms ◽  
A Current ◽  
Made In

The aim of the following experiments was to ascertain whether bacteria suspended in an electrolyte through which a current passes are transmitted to either electrode, and if so, whether pathogenic organisms could be collected and extracted by such means from pathological liquids. Method of Experiment . The first observations as to a possible migration of bacteria under the action of an electric current were made in the following way :— A cover square was fitted with two platinum foil terminals, separated about 6 mm. From each other. A drop of weak bacterial emulsion made electrical connection between these two terminals, and was prevented from evaporating by another cover square resting on the top of the first one, the edges of which were greased; the “glass cell,” as it may be called, was then mounted on a stand (fig. 1), which rested on the stage of a microscope, and a current of about 1 milliampere sent through it.

XXV. Electro-physiological researches.-Fourth Memoir. The physiological action of the electric current

1846 ◽  
Vol 136 ◽  
pp. 483-499 ◽  
Keyword(s):  
Electric Current ◽  
The Other ◽  
Physiological Action ◽  
A Current

In my treatise upon the electro-physiological phenomena of animals, at page 230 I have described the following experiment:-"I prepare a frog after the method adopted by GALVANI, separating the junction of the two thigh-bones, and placing them so divided between two glasses, with the claws immersed in these glasses. Introducing the conductors of a pile of from sixty to eighty pairs in both the glasses, I pass a current through the frog, which is direct in one limb and inverse in the other.

scholarly journals Electro-physiological researches. -7th series

1851 ◽  
Vol 5 ◽  
pp. 902-904
Keyword(s):  
Electric Current ◽  
Direct Action ◽  
Muscular Fibre ◽  
Living Animal ◽  
Chemical Decomposition ◽  
Liquid Part ◽  
Metallic Wires ◽  
A Current ◽  
Indirect Action ◽  
Made In

In this memoir, Prof. Matteucci, after recapitulating the results of his previous researches on electro-physiology, published in the Philosophical Transactions, proceeds to the relation of new experiments. He first shows that nervous filaments made to conduct an electric current in a liquid are not capable, like metallic wires, of acting as electroids, and giving rise to electro-chemical decomposition. The solution employed was that of iodide of potassium; the nerves, two large ones taken from a living animal, each of which was separately attached to the metallic extremities of a pile of fifteen couples. No trace of decomposition followed; and he concludes from hence, that the conductihility of nervous matter is due to the liquid part of the matter itself. He then gives further experiments on the relative conductibility of muscles and nerves, with a view to ascertain whether, when a current was impelled through a mass of muscle, any part of the current might have passed through the nervous filaments spread through that muscle. For this purpose he inserted the nerve of a galvanoscopic frog into a hole made in a piece of dead muscle, through which he then passed a very powerful current: no contraction followed in the galvanoscopic frog. When muscles still retaining their irritability were substituted for the dead muscle, induced contractions occurred in the galvanoscopic frog during the passage of the current. He concludes that when the poles of a pile of twenty-five or thirty elements are applied to the surface of the muscles of a living animal, the phenomena produced by the passage of the current must depend either on the direct action of the current on the muscular fibre, or on the indirect action or influence of the electric current transmitted by the muscular fibre to its own nervous filaments, or rather to the nervous force existing in those filaments.

I. On the effect of occluded gases on the thermo-electric properties of bodies, and on their resistances; also on the thermo-electric and other properties of graphite and car­bon

1888 ◽  
Vol 44 (266-272) ◽  
pp. 220-236 ◽  
Keyword(s):  
Electric Current ◽  
Electric Properties ◽  
The Other ◽  
Thermo Electric ◽  
The Wire ◽  
A Current

" Le Roux has shown that when a notch is filed into a wire and one side heated there is in general a thermo-electric current. He also found that when two wires of the same metal, with flat ends, are pressed together, so that one forms a continuation of the other, and the wire on one side of the junction is heated, no current is obtained, hut he observed a current in all cases where there was dyssymmetry.

Researches into the effects of certain physical and chemical agents on the nervous system

1851 ◽  
Vol 5 ◽  
pp. 667-668
Keyword(s):  
Nervous System ◽  
Electric Current ◽  
Mechanical Injury ◽  
The Body ◽  
The Other ◽  
Hydrocyanic Acid ◽  
Spinal Marrow ◽  
Chemical Agents ◽  
The Subject ◽  
Physical And Chemical

The professed object of the author, in the present paper, is “ to detail the results of an investigation of the phenomena and the laws of production and action of certain secondary or induced conditions of the nervous system, which are effected by a voltaic, and proba­bly by any other electric current, but persistent after the influence of that current is withdrawn.” This condition he designates by the new term electrogenic , as describing at once the origin and the independence of that condition. On the present occasion he confines himself to the subject of the electrogenic condition of the muscular nerves, postponing to future inquiries that of the incident nerves and of the spinal marrow; and also the modes of action of other physical and chemical agents, such as mechanical injury, heat and cold, strychnine, and the hydrocyanic acid. The bones and muscles of the brachial lumbar and pelvic regions of a frog, being isolated from all the other parts of the body, except­ing only by means of their respective brachial and lumbar nerves, which were perfectly denuded on all sides, and raised from the glass on which the limbs were laid, a voltaic current from a pair of the “couronne de tasses” was passed downwards through the nerves, in a direction from their origin in the spinal marrow towards their ter­minations in the muscles. Energetic muscular movements were at first excited; and the current was thus continued during the space of five, ten, or fifteen minutes, and at the end of this period was withdrawn. No sooner was the current discontinued than the mus­cles were affected with spasmodic contractions, and with a tetanoid rigidity, constituting the secondary, or what the author denominates the electrogenic condition ; an effect, which as instantly subsides on the restoration of the voltaic current.

scholarly journals Electro-physiological researches.—Fourth memoir

1851 ◽  
Vol 5 ◽  
pp. 629-629
Keyword(s):  
Electric Current ◽  
Direct Current ◽  
The Other ◽  
Electric Currents ◽  
Physiological Action ◽  
Other Hand ◽  
A Current ◽  
Contrary Direction ◽  
Mixed Nerve

In the prosecution of his inquiries on the physiological action of electric currents, the author found it necessary to employ an apparatus, which was expressly made for him by M. Bréguet, adapted to the delicate appreciation of the intensity of the force of the mus­cular contractions excited by those currents; of which apparatus he gives a minute description, illustrated by a drawing. He was thus enabled to institute an exact comparison between the contrac­tions caused by the direct, and those by the reverse currents, both at the commencement and at the termination of their action. The following are the general conclusions he deduces from the experi­ments thus conducted. 1. The passage of the electric current through a mixed nerve pro­duces a variation in the excitability of the nerve, differing essen­tially in degree, according to the direction of the current through the nerve. This excitability is weakened and ultimately destroyed; and this takes place more or less rapidly according as the direct current , that is, a current circulating through the nerve from the centre to the periphery, is more or less intense. On the other hand, by the passage of the same current in the contrary direction, that is, from the periphery to the centre, or the inverse current , the ex­citability is preserved and increased.

Rem Study of Current Effect on the Structure of Clean Si(111) Surface

1990 ◽  
Vol 48 (1) ◽  
pp. 306-307
Author(s):  
A. Yamanaka ◽  
H. Ohse ◽  
K. Yagi
Keyword(s):  
The Other ◽  
Current Direction ◽  
Clean Surface ◽  
Current Effect ◽  
Atomic Steps ◽  
Step Bunching ◽  
Terrace Width ◽  
Step Down ◽  
A Current

Recently current effects on clean and metal adsorbate surfaces have attracted much attention not only because of interesting phenomena but also because of practically importance in treatingclean and metal adsorbate surfaces [1-6]. In the former case, metals deposited migrate on the deposit depending on the current direction and a patch of the deposit expands on the clean surface [1]. The migration is closely related to the adsorbate structures and substrate structures including their anisotropy [2,7]. In the latter case, configurations of surface atomic steps depends on the current direction. In the case of Si(001) surface equally spaced array of monatom high steps along the [110] direction produces the 2x1 and 1x2 terraces. However, a relative terrace width of the two domain depends on the current direction; a step-up current widen terraces on which dimers are parallel to the current, while a step-down current widen the other terraces [3]. On (111) surface, a step-down current produces step bunching at temperatures between 1250-1350°C, while a step-up current produces step bunching at temperatures between 1050-1250°C [5].In the present paper, our REM observations on a current induced step bunching, started independently, are described.Our results are summarized as follows.(1) Above around 1000°C a step-up current induces step bunching. The phenomenon reverses around 1200 C; a step-down current induces step bunching. The observations agree with the previous reports [5].

On the Future of the Financial Redistribution across Member States in the EU

2006 ◽  
Vol 56 (1) ◽  
pp. 1-43
Author(s):  
Sándor Richter
Keyword(s):  
Value Added ◽  
The Other ◽  
Current Debate ◽  
Member States ◽  
New Member States ◽  
Financial Position ◽  
Cross Member ◽  
Expenditure Structure ◽  
The Eu ◽  
Made In

The order and modalities of cross-member state redistribution as well as the net financial position of the member states are one of the most widely discussed aspects of European integration. The paper addresses selected issues in the current debate on the EU budget for the period 2007 to 2013 and introduces four scenarios. The first is identical to the European Commission's proposal; the second is based on reducing the budget to 1% of the EU's GNI, as proposed by the six net-payer countries, while maintaining the expenditure structure of the Commission's proposal. The next two scenarios represent radical reforms: one of them also features a '1% EU GNI'; however, the expenditures for providing 'EU-wide value-added' are left unchanged and it is envisaged that the requisite cuts will be made in the expenditures earmarked for cohesion. The other reform scenario is different from the former one in that the cohesion-related expenditures are left unchanged and the expenditures for providing 'EU-wide value-added' are reduced. After the comparison of the various scenarios, the allocation of transfers to the new member states in terms of the conditions prevailing in the different scenarios is analysed.

Physical and Mechanical Properties of Tenun Pahang Fabrics using Alternative Yarns

2016 ◽  
Vol 13 (2) ◽  
pp. 67
Author(s):  
Engku Liyana Zafirah Engku Mohd Suhaimi ◽  
Jamil Salleh ◽  
Suzaini Abd Ghani ◽  
Mohamad Faizul Yahya ◽  
Mohd Rozi Ahmad
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Silk Fabrics ◽  
Recovery Angle ◽  
Made In

An investigation on the properties of Tenun Pahang fabric performances using alternative yarns was conducted. The studies were made in order to evaluate whether the Tenun Pahang fabric could be produced economically and at the same time maintain the fabric quality. Traditional Tenun Pahang fabric uses silk for both warp and weft. For this project, two alternative yarns were used which were bamboo and modal, which were a little lower in cost compared to silk. These yarns were woven with two variations, one with the yarns as weft only while maintaining the silk warp and the other with both warp and weft using the alternative yarns. Four (4) physical testings and three (3) mechanical testings conducted on the fabric samples. The fabric samples were evaluated including weight, thickness, thread density, crease recovery angle, stiffness and drapability. The results show that modal/silk and bamboo silk fabrics are comparable in terms of stiffness and drapability, hence they have the potential to replace 100% silk Tenun Pahang.

Sign in / Sign up

Export Citation Format

Share Document