Changes of Internal Hydrostatic Pressure and Body Shape in Acanthocephalus Ranae

1966 ◽  
Vol 45 (2) ◽  
pp. 197-202
Author(s):  
R. A. HAMMOND
Keyword(s):  
Hydrostatic Pressure ◽  
Internal Pressure ◽  
Body Length ◽  
Body Shape ◽  
Muscular Activity ◽  
The Body ◽  
Trunk Muscles ◽  
Rapid Rise ◽  
Indirect Methods ◽  
Pressure Changes

1. Two indirect methods for recording changes of hydrostatic pressure within the trunk of Acanthocephalus ranae have been described. 2. Internal pressure has been shown to be lowest when the trunk is fully contracted and the proboscis invaginated, and highest when the trunk is fully elongated. 3. A rapid rise of internal pressure occurs when the circular trunk muscles contract. 4. Overall internal pressure changes of up to 0.5 cm. Hg have been shown to occur in active specimens. 5. The body length when fully extended is only 40-50% greater than when contracted. 6. The correlation between muscular activity, body shape, and internal hydrostatic pressure in A. ranae is discussed

scholarly journals Analyzing the Response Behavior of Lumbriculus variegatus (Oligochaeta: Lumbriculidae) to Different Concentrations of Copper Sulfate Based on Line Body Shape Detection and a Recurrent Self-Organizing Map

2020 ◽  
Vol 17 (8) ◽  
pp. 2627 ◽  
Author(s):  
Chang Woo Ji ◽  
Young-Seuk Park ◽  
Yongde Cui ◽  
Hongzhu Wang ◽  
Ihn-Sil Kwak ◽  
...  
Keyword(s):  
Body Length ◽  
Copper Sulfate ◽  
Body Shape ◽  
Tracking System ◽  
Total Body Length ◽  
The Body ◽  
Self Organizing Map ◽  
Lumbriculus Variegatus ◽  
Indicator Organisms ◽  
Self Organizing

Point detection (e.g., the centroid of the body) of species has been conducted in numerous studies. However, line detection (i.e., the line body shape) of elongated species has rarely been investigated under stressful conditions. We analyzed the line movements of an Oligochaeta Lumbriculus variegatus in response to treatments with a toxic chemical, copper sulfate, at low concentrations (0.01 mg/L and 0.1 mg/L). The automatic line-tracking system was devised to identify the movement of body segments (body length) and the movements of segments (i.e., the speed and angles between segments) were recorded before and after treatment. Total body length was shortened from 31.22 (±5.18) mm to 20.91 (±4.65) mm after the 0.1 mg/L treatment. The Shannon entropy index decreased from 0.44 (±0.1) to 0.28 (±0.08) after treatment. On the other hand, the body and movement segments did not significantly change after the 0.01 mg/L treatment. Sequential movements of test organisms were further analyzed with a recurrent self-organizing map (RSOM) to determine the pattern of time-series line movements. The RSOM made it feasible to classify sequential behaviors of indicator organisms and identify various continuous body movements under stressful conditions.

Differentiation of external morphology of Damaeidae (Acari: Oribatida) in light of the ontogeny of three species

Zootaxa ◽  
2011 ◽  
Vol 2775 (1) ◽  
pp. 1 ◽  
Author(s):  
STANISŁAW SENICZAK ◽  
ANNA SENICZAK
Keyword(s):  
Body Size ◽  
Body Length ◽  
Body Shape ◽  
The Body ◽  
The Other ◽  
External Morphology ◽  
Dorsal Seta ◽  
Size And Shape ◽  
Juvenile Stages ◽  
Shape And Size

Morphology of juvenile stages and ontogeny of Damaeus onustus C. L. Koch, 1844, Damaeus clavipes (Hermann, 1804) and Kunstidamaeus tecticola (Michael, 1888) was investigated. The juveniles of these species differ mainly in body shape and size, and shape of some setae on the gastronotum and legs. The nymphs of all species lose centrodorsal setae of the d-series, and carry the exuviae of previous instars, but D. onustus carries also compact humus mass adhering to exuviae, D. clavipes a lot of loose debris, while K. tecticola usually only exuviae. The kind of camouflage is partly determined by the shape of gastronotal setae; in D. onustus these setae are curved ventrally, in D. clavipes are raised, while in K. tecticola are raised, and strongly curved medial. The nymphs of these species, as the nymphs of all other known Damaeidae, have gastronotal cornicle, which connects the exuviae of previous instars to the gastronotum. The cornicle of particular species differs in shape and location on the gastronotum; in some species is located anteromedial to setae la, in the other between setae lm, and in the other yet between setae lp or h 3 . The adults of these species differ mainly in body size, presence and shape of cuticular apophyses on the body, length of some setae on the prodorsum and notogaster, and the number of setae on legs, including dorsal seta d on genua I–III and tibiae I–IV.

scholarly journals Muscular and Hydrostatic Action in the Sea-Anemone Metridium Senile (L.)

1950 ◽  
Vol 27 (3) ◽  
pp. 264-289 ◽  
Author(s):  
E. J. BATHAM ◽  
C. F. A. PANTIN
Keyword(s):  
Body Wall ◽  
Circular Muscle ◽  
Muscular Activity ◽  
Isometric Tension ◽  
The Body ◽  
Muscle Fibres ◽  
Skeletal System ◽  
Metridium Senile ◽  
Pressure Changes ◽  
Muscular Action

1. In contrast with most other Actinians, Metridium senile exhibits a great variety of shapes of the body. These are brought about by continual slow muscular activity. The mechanics of muscular action are discussed. The action of most of the muscles is extremely slow. An isotonic contraction of the parietal muscles requires 40-60 sec. to reach its maximum and many minutes to relax. The body wall is capable of extension by about 400%. There are limits to extensibility in the normal animal. The mechanisms by which the animal itself increases or reduces extension by controlling its coelenteric volume are described. Fluid is gained chiefly through the siphonoglyph, though under certain conditions there may be suction into the coelenteron. Fluid is lost chiefly through reflex opening of the mouth. From time to time Metridium empties itself of fluid, and then refills in a few hours. A rate of refilling of 14 c.c./hr. has been measured. 2. Pressure changes in the coelenteron which occur during activity show that both retraction and extension of the column are active processes involving a rise in pressure which enforces reciprocal extension of the opposing musculature. 3. The relation of normal activity and shape to the coelenteric pressure is shown. This average pressure is extremely low; about 2-3 mm. of water. In a moderately filled unstimulated animal the natural muscular contractions are accompanied by a rise in pressure not generally exceeding 6-7 mm. of water. In such animals the natural contractions are of considerable extent, reaching over 30% of the body length. 4. By experimental inflation of the coelenteron with sea water, the system can be made to work more isometrically. The extent of movement is reduced and the animal may appear inactive. The presence of considerable though ineffective muscular activity is shown by the fact that large pressure changes (up to about 12 mm. of water) now take place. By raising the coelenteric pressure increased contractile activity in the body wall may actually reduce the extent of movement. 5. The isometric pressure which the body wall can develop in the coelenteron has been estimated. Pressures developed during natural contractions of a moderately filled animal demand muscular tensions in the body wall ranging between 20 and 50% of the isometric tension. The range of tension corresponds to that which would be most mechanically efficient if Metridium muscle resembles that of other animals. 6. An estimate is deduced from the coelenteric pressure of the isometric tension developed by the circular muscle of the column of Metridium. It is about 3-5 g./cm. of body wall transverse to the muscle. This is in agreement with direct observation of the isometric tension developed by strips of circular muscle. This tension in the column may correspond to a tension of 40 kg./sq.cm. of the individual muscle fibres and is very much greater than the values obtained from the frog's sartorius. 7. The extensive responses of the powerful retractor muscles involve much greater pressures (40-100 mm.) than those against which the column muscles can operate. The development of these muscles is related to the necessity of speed of action in a system undergoing great deformation. 8. Muscular action in a hydrostatic skeletal system is contrasted with that in the jointed skeletal system of Vertebrates and Arthropods. The former system is characterized by slowness of action and great change of length. In contrast with the Vertebrate skeletal system, in the hydrostatic system reciprocal muscular action is not localized. The movement of every muscle influences the mechanical conditions of every other in the system. Each muscle has two actions, a local direct action, and an indirect action, as in the elongation of Metridium on contraction of the circular muscles. The consequences of this are discussed.

Updating long-held assumptions about fat stigma: For women, body shape plays a critical role

2020 ◽  
Author(s):  
Jaimie Krems ◽  
Steven L. Neuberg
Keyword(s):  
Body Shape ◽  
Critical Role ◽  
The Body ◽  
Theoretical Assumption ◽  
Obesity Stigma ◽  
Obese Female ◽  
Three Samples ◽  
Female Bodies ◽  
Different Parts ◽  
Fat Stigma

Heavier bodies—particularly female bodies—are stigmatized. Such fat stigma is pervasive, painful to experience, and may even facilitate weight gain, thereby perpetuating the obesity-stigma cycle. Leveraging research on functionally distinct forms of fat (deposited on different parts of the body), we propose that body shape plays an important but largely underappreciated role in fat stigma, above and beyond fat amount. Across three samples varying in participant ethnicity (White and Black Americans) and nation (U.S., India), patterns of fat stigma reveal that, as hypothesized, participants differently stigmatized equally-overweight or -obese female targets as a function of target shape, sometimes even more strongly stigmatizing targets with less rather than more body mass. Such findings suggest value in updating our understanding of fat stigma to include body shape and in querying a predominating, but often implicit, theoretical assumption that people simply view all fat as bad (and more fat as worse).

Chaos in body–vortex interactions

2010 ◽  
Vol 466 (2119) ◽  
pp. 1871-1891 ◽  
Author(s):  
Johan Roenby ◽  
Hassan Aref
Keyword(s):  
Body Shape ◽  
Mass Density ◽  
Relative Equilibrium ◽  
Large Body ◽  
Point Vortex ◽  
Cylindrical Body ◽  
The Body ◽  
Body Motion ◽  
Single Vortex ◽  
Vortex Interactions

The model of body–vortex interactions, where the fluid flow is planar, ideal and unbounded, and the vortex is a point vortex, is studied. The body may have a constant circulation around it. The governing equations for the general case of a freely moving body of arbitrary shape and mass density and an arbitrary number of point vortices are presented. The case of a body and a single vortex is then investigated numerically in detail. In this paper, the body is a homogeneous, elliptical cylinder. For large body–vortex separations, the system behaves much like a vortex pair regardless of body shape. The case of a circle is integrable. As the body is made slightly elliptic, a chaotic region grows from an unstable relative equilibrium of the circle-vortex case. The case of a cylindrical body of any shape moving in fluid otherwise at rest is also integrable. A second transition to chaos arises from the limit between rocking and tumbling motion of the body known in this case. In both instances, the chaos may be detected both in the body motion and in the vortex motion. The effect of increasing body mass at a fixed body shape is to damp the chaos.

scholarly journals Sea stars generate downforce to stay attached to surfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mark Hermes ◽  
Mitul Luhar
Keyword(s):  
Body Shape ◽  
Control Volume ◽  
Water Channel ◽  
Morphological Plasticity ◽  
The Body ◽  
Sea Star ◽  
Sea Stars ◽  
Hydrodynamic Loads ◽  
Spherical Dome ◽  
Star Models

AbstractIntertidal sea stars often function in environments with extreme hydrodynamic loads that can compromise their ability to remain attached to surfaces. While behavioral responses such as burrowing into sand or sheltering in rock crevices can help minimize hydrodynamic loads, previous work shows that sea stars also alter body shape in response to flow conditions. This morphological plasticity suggests that sea star body shape may play an important hydrodynamic role. In this study, we measured the fluid forces acting on surface-mounted sea star and spherical dome models in water channel tests. All sea star models created downforce, i.e., the fluid pushed the body towards the surface. In contrast, the spherical dome generated lift. We also used Particle Image Velocimetry (PIV) to measure the midplane flow field around the models. Control volume analyses based on the PIV data show that downforce arises because the sea star bodies serve as ramps that divert fluid away from the surface. These observations are further rationalized using force predictions and flow visualizations from numerical simulations. The discovery of downforce generation could explain why sea stars are shaped as they are: the pentaradial geometry aids attachment to surfaces in the presence of high hydrodynamic loads.

scholarly journals Digital 3D models of theropods for approaching body-mass distribution and volume

2021 ◽  
Author(s):  
Matías Reolid ◽  
Francisco J. Cardenal ◽  
Jesús Reolid
Keyword(s):  
Body Length ◽  
Heat Dissipation ◽  
Volume Ratio ◽  
3D Models ◽  
The Body ◽  
3D Analysis ◽  
Skull Length ◽  
Knowing That ◽  
Fossil Bones ◽  
Primitive Forms

AbstractThe aim of this work is to obtain diverse morphometric data from digitized 3D models of scientifically accurate palaeoreconstructions of theropods from eight representative families. The analysed polyvinyl chloride (PVC) models belong to the genera Coelophysis, Dilophosaurus, Ceratosaurus, Allosaurus, Baryonyx, Carnotaurus, Giganotosaurus, and Tyrannosaurus. The scanned 3D models were scaled considering different body-size estimations of the literature. The 3D analysis of these genera provides information on the skull length and body length that allows for recognition of major evolutionary trends. The skull length/body length in the studied genera increases according with the size of the body from the smallest Coelophysis with a ratio of 0.093 to ratios of 0.119–0.120 for Tyrannosaurus and Giganotosaurus, the largest study theropods. The study of photogrammetric 3D models also provides morphometric information that cannot be obtained from the study of bones alone, but knowing that all reconstructions begin from the fossil bones, such as the surface/volume ratio (S/V). For the studied theropod genera surface/volume ratio ranges from 35.21 for Coelophysis to 5.55 for Tyrannosaurus. This parameter, closely related to the heat dissipation, help in the characterization of the metabolism of extinct taxa. Accordingly, slender primitive forms of the Early Jurassic (i.e. Coelophysis and Dilophosaurus) had relatively smaller skulls and higher mass-specific metabolic rates than the robust large theropods of the Cretaceous (i.e. Giganotosaurus and Tyrannosaurus). This work presents a technique that, when applied to proper dinosaur models, provides extent and accurate data that may help in diverse study areas within the dinosaur palaeontology and palaeobiology.

The history of anabolic steroids and a review of clinical experience with anabolic steroids

1985 ◽  
Vol 110 (3_Suppla) ◽  
pp. S11-S18 ◽  
Author(s):  
H. Kopera
Keyword(s):  
Protein Synthesis ◽  
Protein Metabolism ◽  
Anabolic Steroids ◽  
Muscular Activity ◽  
Living Cells ◽  
Cellular Protein ◽  
Complex Compounds ◽  
The Body ◽  
Anabolic Effect ◽  
Vital Functions

Metabolism is the term employed to embrace the various physical and chemical processes occurring within the tissues upon which the growth and heat production of the body depend and from which the energy for muscular activity, for the maintenance of vital activity and for the maintenance of vital functions is derived (Best & Taylor 1950). The destructive processes by which complex substances are converted by living cells into more simple compounds are called catabolism. Anabolism denotes the constructive processes by which simple substances are converted by living cells into more complex compounds, especially into living matter. Catabolism and anabolism are part of all metabolic processes, the carbohydrate, fat and protein metabolism. The term anabolic refers only to substances that exert an anabolic effect on protein metabolism and are unlikely to cause adverse androgenic effects. They shift the equilibrium between protein synthesis and degradation in the body as a whole in the direction of synthesis, either by promoting protein synthesis or reducing its breakdown. The protein anabolic effect of anabolic steroids is not restricted to single organs but is the result of stimulated biosynthesis of cellular protein in the whole organism.

Survey on the Indirect Methods of Potential Flow Used for the Optimization of Airships Profile

2014 ◽  
Vol 554 ◽  
pp. 717-723
Author(s):  
Reza Abbasabadi Hassanzadeh ◽  
Shahab Shariatmadari ◽  
Ali Chegeni ◽  
Seyed Alireza Ghazanfari ◽  
Mahdi Nakisa
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Flow Field ◽  
Drag Coefficient ◽  
Body Surface ◽  
Potential Flow ◽  
The Body ◽  
Indirect Methods ◽  
Singularity Method ◽  
Singularity Distribution

The present study aims to investigate the optimized profile of the body through minimizing the Drag coefficient in certain Reynolds regime. For this purpose, effective aerodynamic computations are required to find the Drag coefficient. Then, the computations should be coupled thorough an optimization process to obtain the optimized profile. The aerodynamic computations include calculating the surrounding potential flow field of an object, calculating the laminar and turbulent boundary layer close to the object, and calculating the Drag coefficient of the object’s body surface. To optimize the profile, indirect methods are used to calculate the potential flow since the object profile is initially amorphous. In addition to the indirect methods, the present study has also used axial singularity method which is more precise and efficient compared to other methods. In this method, the body profile is not optimized directly. Instead, a sink-and-source singularity distribution is used on the axis to model the body profile and calculate the relevant viscose flow field.

The development and validation of the body shape questionnaire

1987 ◽  
Vol 6 (4) ◽  
pp. 485-494 ◽  
Author(s):  
Peter J. Cooper ◽  
Melanie J. Taylor ◽  
Zafra Cooper ◽  
Christopher G. Fairbum
Keyword(s):  
Body Shape ◽  
The Body ◽  
Development And Validation
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