The Possible Role of the Supra-Oesophageal Ganglion in the Responses of Nephtys (Polychaeta, Annelida) to Changes in Hydrostatic Pressure

1969 ◽  
Vol 51 (1) ◽  
pp. 171-179
Author(s):  
ELFED MORGAN
Keyword(s):  
Hydrostatic Pressure ◽  
The Body ◽  
Swimming Activity ◽  
Tail Region ◽  
Sensory Structures

1. The swimming activity of the isolated ‘tail’ region of Nephtys is not affected by changes in hydrostatic pressure. In contrast the responses shown by the isolated anterior third of the body are indistinguishable from those of intact worms. 2. Decerebration, or transection of both circum-oesophageal connectives, also destroys the worms' ability to respond, whereas transection of the connective on one side only does not. 3. Not one of the sensory structures hitherto described in association with the supra-oesophageal ganglion appears to be the sole mediator of the response.

The Role of the Coelomic Fluid in the Movements of Earthworms

1950 ◽  
Vol 27 (1) ◽  
pp. 110-122 ◽  
Author(s):  
G. E. NEWELL
Keyword(s):  
Short Review ◽  
The Body ◽  
Coelomic Fluid ◽  
Average Pressure ◽  
Normal Range ◽  
Tail Region ◽  
X Ray ◽  
Effective Barrier ◽  
Intrinsic Muscles

1. A short review is given of the coelom and of its morphological relations in the earthworm. 2. The arrangement of the intrinsic muscles in a typical septum is described. Four main sets of muscles are recognized: viz. radial muscles, circular muscles, oblique muscles, and the sphincter around the ventral foramen. 3. It is suggested that the function of the radial, circular and possibly of the oblique muscles is to control bulging of the septa, and so serve to localize differences in pressure in the coelomic fluid. Normally, in active worms, the sphincter of the ventral foramen is contracted and forms an effective barrier to the passage of fluid from one coelomic compartment to the next. This was verified experimentally and by X-ray photography. 4. A series of measurements of the pressure in the coelomic fluid in different regions of active worms was recorded by means of a capillary manometer and by the use of a spoon-gauge apparatus. Manometric measurements showed the average pressure in the anterior third of the body to be 16.0 cm. water and in the tail region to be 8.0 cm. water. The corresponding figures obtained with a spoon gauge were 13.5 and 8.5 cm. water. The pressure in narcotized worms is zero. 5. These results are discussed, and it is pointed out that the manometer readings suffer from the disadvantage of failing to show the rapid fluctuations in pressure which occur during wriggling movements of the worms. 6. It is calculated from these pressure readings that a worm can exert a forward thrust equivalent to forces of between 1.5 and 8.0 g. These figures agree well with those obtained by Gray & Lissman by the use of a special torsion balance. 7. The burrowing movements of earthworms are briefly described. 8. It is shown that the sphincters of the dorsal pores and of the nephridiopores do not normally allow of the escape of coelomic fluid, and will withstand a pressure well outside the normal range.

Of the Movement of Worms

1950 ◽  
Vol 27 (1) ◽  
pp. 29-39 ◽  
Author(s):  
GARTH CHAPMAN
Keyword(s):  
Hydrostatic Pressure ◽  
Closed System ◽  
Body Fluid ◽  
The Body ◽  
Cross Sectional ◽  
Working Length ◽  
Cylindrical Form ◽  
Maximum Thrust

Four aspects of the functioning of a fluid-filled cylindrical animal have been examined, viz.: (I) the role of the body fluid as a skeleton for the interaction of the longitudinal and circular muscles of which the animal must be composed; (2) the measurement of the maximum thrust which the animal can exert by measurement of its internal hydrostatic pressure; (3) the application of the force to the substratum and the part played by friction; (4) the relation between the changes in dimensions of the animal and the working length of the muscles. Under (1) the necessity for a longitudinal and circular construction has been shown and the necessity for a closed system emphasized. Under (2) the pressure exerted on the body fluid by the contraction of the longitudinal and circular muscles is discussed, and from their cross-sectional areas it is shown to be probable that when contracting maximally in Lumbricus they are not balanced, but that the longitudinals are about ten times as strong as the circulars. Under (3) it is shown that the strength of an animal as measured by its internal hydrostatic pressure is sufficient to account for its customary activities. Use which may be made of the longitudinals during burrowing is pointed out. Under (4) it is shown to be mechanically sound for burrowing animals of cylindrical form to be ‘fat’, but that a ‘thin’ animal is more efficient at progression.

scholarly journals The role of adrenoreceptors in the implementation of the stimulatory effect of serotonin on the gastric motor activity

2020 ◽  
Vol 1 (10) ◽  
pp. 52-56
Author(s):  
V. M. Smirnov ◽  
D. S. Sveshnikov ◽  
A. V. Kuchuk ◽  
T. E. Kuznetsova ◽  
O. S. Raevskaya ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Motor Activity ◽  
The Body ◽  
Analog To Digital Converter ◽  
Digital Converter ◽  
Stimulatory Action ◽  
Analog To Digital ◽  
Gastric Motor Activity ◽  
Gastric Contractions

Purpose of the study — study of the role of adrenoreceptors in the development of the stimulatory action of serotonin on the gastric motor activity.Materials and methods. The experiments were performed on rats (27) of the Wistar line in the surgical stage of anesthesia. Electromyogram and hydrostatic pressure in the stomach cavity were recorded using a BioAmp ML132 amplifier (Adinstruments, Australia), an Maclab 8e analog-to-digital converter (Adinstruments, Australia), a Macintosh Performa 6400/180 computer, and Chart 4.2.3. program. Serotonin injected into the body to intact animals and against the background of separate and joint blockade of α- and β-adrenoreceptors.The results of the study. In experiments on rats established that the preliminary simultaneous blockade of α- and β- adrenoreceptors leads to an increase in the stimulatory effect of the stomach with the introduction of serotonin by 58%, blockade of α-adrenoreceptors only — by 62%, β-adrenoreceptor blockade — by 89%. In intact animals, the stimulatory eff ect of serotonin is only + 26%. Simultaneous blockade of α- and β-adrenoreceptors and blockade of α-adrenoreceptors only (without serotonin administration) did not aff ect the gastric motor activity of intact animals. Blockade only β-adrenoreceptors will lead to an increase in gastric contractions by 34%.Conclusion. Intact α- and β-adrenoreceptors inhibit the stimulatory eff ect of serotonin on gastric motor activity.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

The Role of Computer Modeling in Electrocardiography

1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom
Keyword(s):  
Electrical Activity ◽  
Computer Modeling ◽  
Body Surface ◽  
Electrical Current ◽  
The Body ◽  
Volume Conductor ◽  
Current Generator ◽  
Cardiac Electrical Activity ◽  
Source Models

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.

Questions on the role of biofilms for the adaptation of microorganisms to unfavorable environmental factors by the example of P. aeruginosa

2020 ◽  
Vol 99 (4) ◽  
pp. 379-383
Author(s):  
Vasily N. Afonyushkin ◽  
N. A. Donchenko ◽  
Ju. N. Kozlova ◽  
N. A. Davidova ◽  
V. Yu. Koptev ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Environmental Factors ◽  
Barrier Function ◽  
Infectious Agent ◽  
Antagonistic Activity ◽  
The Body ◽  
Main Function ◽  
Pathogenic Potential ◽  
The Face

Pseudomonas aeruginosa is a widely represented species of bacteria possessing of a pathogenic potential. This infectious agent is causing wound infections, fibrotic cystitis, fibrosing pneumonia, bacterial sepsis, etc. The microorganism is highly resistant to antiseptics, disinfectants, immune system responses of the body. The responses of a quorum sense of this kind of bacteria ensure the inclusion of many pathogenicity factors. The analysis of the scientific literature made it possible to formulate four questions concerning the role of biofilms for the adaptation of P. aeruginosa to adverse environmental factors: Is another person appears to be predominantly of a source an etiological agent or the source of P. aeruginosa infection in the environment? Does the formation of biofilms influence on the antibiotic resistance? How the antagonistic activity of microorganisms is realized in biofilm form? What is the main function of biofilms in the functioning of bacteria? A hypothesis has been put forward the effect of biofilms on the increase of antibiotic resistance of bacteria and, in particular, P. aeruginosa to be secondary in charcter. It is more likely a biofilmboth to fulfill the function of storing nutrients and provide topical competition in the face of food scarcity. In connection with the incompatibility of the molecular radii of most antibiotics and pores in biofilm, biofilm is doubtful to be capable of performing a barrier function for protecting against antibiotics. However, with respect to antibodies and immunocompetent cells, the barrier function is beyond doubt. The biofilm is more likely to fulfill the function of storing nutrients and providing topical competition in conditions of scarcity of food resources.

Receptions of the Past: Commemoration, Racism, Desire

Somatechnics ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 288-303
Author(s):  
Michael Connors Jackman
Keyword(s):  
Critical Point ◽  
Social Relations ◽  
White Privilege ◽  
Body Politic ◽  
The Body ◽  
Race And Racism ◽  
Lesbian And Gay ◽  
The Past ◽  
History Of

This article investigates the ways in which the work of The Body Politic (TBP), the first major lesbian and gay newspaper in Canada, comes to be commemorated in queer publics and how it figures in the memories of those who were involved in producing the paper. In revisiting a critical point in the history of TBP from 1985 when controversy erupted over race and racism within the editorial collective, this discussion considers the role of memory in the reproduction of whiteness and in the rupture of standard narratives about the past. As the controversy continues to haunt contemporary queer activism in Canada, the productive work of memory must be considered an essential aspect of how, when and for what reasons the work of TBP comes to be commemorated. By revisiting the events of 1985 and by sifting through interviews with individuals who contributed to the work of TBP, this article complicates the narrative of TBP as a bluntly racist endeavour whilst questioning the white privilege and racially-charged demands that undergird its commemoration. The work of producing and preserving queer history is a vital means of challenging the intentional and strategic erasure of queer existence, but those who engage in such efforts must remain attentive to the unequal terrain of social relations within which remembering forms its objects.

A Good Sentencing Precedent is Hard to Find

2020 ◽  
Vol 32 (3) ◽  
pp. 138-144
Author(s):  
Brian A. Jacobs
Keyword(s):  
United States ◽  
Significant Role ◽  
College Admissions ◽  
The Body ◽  
Federal Law ◽  
Criminal Cases ◽  
Federal Sentencing

In federal criminal cases, federal law requires that judges consider the sentences other courts have imposed in factually similar matters. Courts and parties, however, face significant challenges in finding applicable sentencing precedents because judges do not typically issue written sentencing opinions, and transcripts of sentencings are not readily available in advanced searchable databases. At the same time, particularly since the Supreme Court’s 2005 decision in United States v. Booker, sentencing precedent has come to play a significant role in federal sentencing proceedings. By way of example, this article discusses recent cases involving defendants with gambling addictions, and recent cases involving college admissions or testing fraud. The article explores the ways the parties in those cases have used sentencing precedent in their advocacy, as well as the ways the courts involved have used sentencing precedent to justify their decisions. Given the important role of sentencing precedent in federal criminal cases, the article finally looks at ways in which the body of sentencing law could be made more readily available to parties and courts alike.

Putting the Madhyamaka Trick in Context: A Contextualist Reading of Huntington’s Interpretation of Madhyamaka

2014 ◽  
Vol 31 (1) ◽  
pp. 91-124
Author(s):  
Michael Dorfman
Keyword(s):  
Fifteenth Century ◽  
Common Ground ◽  
Correspondence Theory ◽  
The Body ◽  
Rational Analysis ◽  
At Command ◽  
Rational Argumentation ◽  
Logical Fallacies ◽  
Key Terms

In a series of works published over a period of twenty five years, C.W. Huntington, Jr. has developed a provocative and radical reading of Madhyamaka (particularly Early Indian Madhyamaka) inspired by ‘the insights of post- Wittgensteinian pragmatism and deconstruction’ (1993, 9). This article examines the body of Huntington’s work through the filter of his seminal 2007 publication, ‘The Nature of the M?dhyamika Trick’, a polemic aimed at a quartet of other recent commentators on Madhyamaka (Robinson, Hayes, Tillemans and Garfield) who attempt ‘to read N?g?rjuna through the lens of modern symbolic logic’ (2007, 103), a project which is the ‘end result of a long and complex scholastic enterprise … [which] can be traced backwards from contemporary academic discourse to fifteenth century Tibet, and from there into India’ (2007, 111) and which Huntington sees as distorting the Madhyamaka project which was not aimed at ‘command[ing] assent to a set of rationally grounded doctrines, tenets, or true conclusions’ (2007, 129). This article begins by explicating some disparate strands found in Huntington’s work, which I connect under a radicalized notion of ‘context’. These strands consist of a contextualist/pragmatic theory of truth (as opposed to a correspondence theory of truth), a contextualist epistemology (as opposed to one relying on foundationalist epistemic warrants), and a contextualist ontology where entities are viewed as necessarily relational (as opposed to possessing a context-independent essence.) I then use these linked theories to find fault with Huntington’s own readings of Candrak?rti and N?g?rjuna, arguing that Huntington misreads the semantic context of certain key terms (tarka, d???i, pak?a and pratijñ?) and fails to follow the implications of N?g?rjuna and Candrak?rti’s reliance on the role of the pram??as in constituting conventional reality. Thus, I find that Huntington’s imputation of a rejection of logic and rational argumentation to N?g?rjuna and Candrak?rti is unwarranted. Finally, I offer alternate readings of the four contemporary commentators selected by Huntington, using the conceptual apparatus developed earlier to dismiss Robinson’s and Hayes’s view of N?g?rjuna as a charlatan relying on logical fallacies, and to find common ground between Huntington’s project and the view of N?g?rjuna developed by Tillemans and Garfield as a thinker committed using reason to reach, through rational analysis, ‘the limits of thought.’

Ghrelin and Obesity-An Update

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Gandhi M. ◽  
Swaminathan S.
Keyword(s):  
Diabetes Mellitus ◽  
Cardiac Output ◽  
Energy Balance ◽  
Vascular Resistance ◽  
The Body ◽  
Ghrelin Receptor ◽  
Type2 Diabetes ◽  
Type2 Diabetes Mellitus ◽  
Natural Hormones

Ghrelin as human natural hormones is involved in fundamental regulatory process of eating and energy balance. It is a stomach derived hormone that acts as at the ghrelin receptor in multiple tissues throughout to the body. Its properties includes increasing appetite, decreasing systemic inflammation, decreasing vascular resistance ,increasing cardiac output, increasing glucose and IGF-1 levels, Hence it may play a significant role in Diabetes mellitus. Many studies have linked ghrelin to obesity and this paper is an attempt to bring out recent findings on the role of ghrelin in Diabetes Mellitus, particularly type2 Diabetes mellitus.

Sign in / Sign up

Export Citation Format

Share Document