scholarly journals The Effects of Hypergravity on Xenopus Embryo Growth and Cardiac Hypertrophy

2012 ◽  
Vol 11 (1 and 2) ◽  
Author(s):  
Bryce Duchman ◽  
Darrell Wiens
Keyword(s):  
Xenopus Laevis ◽  
Body Length ◽  
Cardiac Tissue ◽  
Cross Sectional Area ◽  
The Body ◽  
Sectional Area ◽  
Cross Sectional ◽  
Organism Growth ◽  
Ventricle Size ◽  
Average Body

All life on earth has developed and evolved in a unity gravity (1G) environment. Any deviation below or above 1G could affect animal development, a period when much change occurs and sensitivity is high. We imposed simulated hypergravity through centrifugation and analyzed the effects on the overall body length and cardiac growth of Xenopus laevis embryos. We predicted that increased contractile force would be required from the heart to adequately circulate blood, dispersing nutrients, and that this would inhibit organism growth and possibly induce a state of hypertrophy. Embryos reaching gastrulation stage were exposed to a 7G or 1G (control) field via centrifugation for 96 hours. We then recorded behavior, mortality and took body length measurements. We found no significant differences in behavior or mortality, however, body length was significantly reduced by an average of 6.8% in the 7G group. We then fixed, embedded, sectioned and stained embryos in order to investigate the dimensions of cardiac tissue and of the cardiac region of the body using image analysis software. We found the 7G group had a significantly reduced average body cross-sectional area (-18%) and yet a significantly larger ventricular cross-sectional area (+36%) when compared to the 1G group. The average ratio of ventricle cross-sectional area to average body cross-sectional area was significantly higher in the 7G group when compared to the 1G. From these data, we conclude that hypergravity has a significant inhibitory impact on the Xenopus laevis embryo growth and causes a significant increase in ventricle size.

Correlation between the Minimal Cross-Sectional Area of the Nasal Cavity and Body Surface Area: Preliminary Results in Normal Patients

2002 ◽  
Vol 16 (4) ◽  
pp. 209-213 ◽  
Author(s):  
Martin Jurlina ◽  
Ranko Mladina ◽  
Krsto Dawidowsky ◽  
Davor Ivanković ◽  
Zeljko Bumber ◽  
...  
Keyword(s):  
Surface Area ◽  
Body Surface Area ◽  
Body Surface ◽  
Anterior Part ◽  
Inferior Turbinate ◽  
Objective Evaluation ◽  
Cross Sectional Area ◽  
The Body ◽  
Sectional Area ◽  
Cross Sectional

Nasal symptoms often are inconsistent with rhinoscopic findings. However, the proper diagnosis and treatment of nasal pathology requires an objective evaluation of the narrow segments of the anterior part of the nasal cavities (minimal cross-sectional area [MCSA]). The problem is that the value of MCSA is not a unique parameter for the entire population, but rather it is a distinctive value for particular subject (or smaller groups of subjects). Consequently, there is a need for MCSA values to be standardized in a simple way that facilitates the comparison of results and the selection of our treatment regimens. We examined a group of 157 healthy subjects with normal nasal function. A statistically significant correlation was found between the body surface area and MCSA at the level of the nasal isthmus and the head of the inferior turbinate. The age of subjects was not found a statistically significant predictor for the value of MCSA. The results show that the expected value of MCSA can be calculated for every subject based on anthropometric data of height and weight.

The Vertical Mean Force and Moment of Submerged Bodies Under Waves

1971 ◽  
Vol 15 (03) ◽  
pp. 231-245 ◽  
Author(s):  
C. M. Lee ◽  
J. N. Newman
Keyword(s):  
Free Surface ◽  
Added Mass ◽  
Cross Sectional Area ◽  
The Body ◽  
Slender Body ◽  
Longitudinal Distribution ◽  
Vertical Force ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Mean

A neutrally buoyant slender body of arbitrary sectional form, submerged beneath a free surface, is free to respond to an incident plane progressive wave system. The fluid is assumed inviscid, incompressible, homogeneous and infinitely deep. The first-order oscillatory motion of the body and the second-order time-average vertical force and pitching moment acting on the body are obtained in terms of Kochin's function. By use of slender-body theory for a deeply submerged body, the final expressions for the mean force and the moment are shown to depend on the longitudinal distribution of sectional area and added mass and on the amplitude and the frequency of the ambient surface waves. The magnitude of the mean force for various simple geometric cylinders is compared with that of a circular cylinder of equal cross-sectional area. The mean force on a nonaxisymmetric body is often approximated by replacing the section with circular profiles of equivalent cross-sectional area. A better scheme of approximation is presented, based on a simple way of estimating the two-dimensional added mass. It is expected that the effect of the cross-sectional geometry on mean vertical force and moment will be more significant when the body is very close to the free surface.

CFD Solution of a Two-Canopy Parachute in a Top-to-Top Formation With a Vent of Air From One of Its Canopy

2008 ◽  
Author(s):  
Mohammad J. Izadi
Keyword(s):  
Cross Sectional Area ◽  
The Body ◽  
The Other ◽  
Bluff Bodies ◽  
Variable Cross ◽  
Sectional Area ◽  
Cross Sectional ◽  
Drag Forces ◽  
Varied Form ◽  
Two Bodies

A CFD study of a 3 Dimensional flow field around two bodies (Two Canopies of a Parachutes) as two bluff bodies in an incompressible fluid (Air) is modeled here. Formations of these two bodies are top-to-top (One on the top of the other) with respect to the center of each other. One canopy with a constant cross sectional area with a vent of air at its apex, and the other with a variable cross sectional area with no vent is studied here. Vertical distances of these two bodies are varied form zero to half, equal, double and triple radius of the body with a vent on it. The flow condition is considered to be 3-D, unsteady, turbulent, and incompressible. The vertical distances between the bluff bodies, cross sectional area, and also vent ratio of bluff bodies are varied here. The drag forces with static pressures around the two bodies are calculated. From the numerical results, it can be seen that, the drag coefficient is constant on the range of zero to twenty percent of the vent ratio and it decreases for higher vent ratios for when the upper parachute is smaller than the lower one, and it increases for when the upper parachute is larger than the lower one. Both Steady and Unsteady cases gave similar results especially when the distance between the canopies is increased.

scholarly journals An Analytical Simulation of Boundary Roughness for Incompressible Viscous Flows

2021 ◽  
Vol 16 ◽  
pp. 9-15
Author(s):  
John Venetis
Keyword(s):  
Flow Direction ◽  
Deformable Body ◽  
Cross Sectional Area ◽  
The Body ◽  
Sectional Area ◽  
Cross Sectional ◽  
Random Roughness ◽  
Analytical Simulation ◽  
The Cross ◽  
Boundary Roughness

The intention of this paper is to investigate the boundary roughness of a mounted obstacle which is inserted into an incompressible, external and viscous flow field of a Newtonian fluid. In particular, the present study focuses on the cross – sectional area of the obstacle, which is assumed to be a non deformable body (rigid object) with a predefined shape of random roughness. For facility reasons and without violating the generality, one may select the cross – section of the body which contains its center of gravity and is perpendicular to the main flow direction. The boundary of this cross – sectional area is mathematically simulated as the polygonal path of the length of a single – valued continuous function. Evidently, this function should be of bounded variation. The novelty of this work is that the formulation of the random roughness of the boundary has been carried out in a deterministic manner.

Numerical Effect of Airflow From a Lower Canopy (Bluff Body) Into an Upper Canopy in Steady and Turbulent Condition

2008 ◽  
Author(s):  
Mohammad J. Izadi
Keyword(s):  
Drag Force ◽  
Bluff Body ◽  
Cross Sectional Area ◽  
The Body ◽  
Bluff Bodies ◽  
Variable Cross ◽  
Sectional Area ◽  
Cross Sectional ◽  
Varied Form ◽  
Two Bodies

In this paper, a 3-D flow field around two bluff bodies in an incompressible fluid is modeled [1]. Formations of these two bodies are top to top (One on the top of the other) with respect to the center of each other. The lower on has a constant cross sectional area with a vent of air at its apex and the upper one has a variable cross sectional area with no vent on it. The vertical distances between the bluff bodies, the cross sectional area, and also the vent ratio of bluff bodies are varied here. Vertical distances of these two bodies are varied form zero to half, equal, double and triple the radius of the body with a vent on it (lower body). Flow condition is considered 3D, steady, turbulent, and incompressible. The drag force on each body and also the pressure around the two bodies are calculated. From the numerical results, it can be seen that, the drag force is constant over the range of zero to twenty percent of the vent ratios and for higher vent ratios when the upper bluff body is smaller than the lower one the drag force decreased, and it increased when the upper bluff body is larger than the lower one.

Fleece characters and their influence on wool production per unit area of skin in Merino sheep

1958 ◽  
Vol 9 (3) ◽  
pp. 363 ◽  
Author(s):  
SSY Young ◽  
RE Chapman
Keyword(s):  
Unit Area ◽  
Fibre Diameter ◽  
Fibre Volume ◽  
Cross Sectional Area ◽  
The Body ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fibre Density ◽  
Wool Production ◽  
Staple Length

The variations in fleece characters and the dependence of wool production per unit area of skin on these characters were studied with 15 sheep in both a medium and a strong-wool strain of Merino. Small but significant differences in staple length and fibre diameter were found between regions on the body, whereas differences in density were large. The variation in density was about three times as large as those in staple length and fibre diameter. Distinct dorsoventral and anteroposterior gradients over the body existed for fibre density, but not for staple length and fibre diameter. The influences of the fleece characters on wool production per unit area were somewhat different in the two strains, and changed with level of production. Among the medium-wool sheep, fibre density had the largest effect on production, with staple length less and mean fibre cross-sectional area least. Among the strong-wool sheep, length was more important than density, which in turn was more important than fibre cross-sectional area. The combined data indicated that as mean wool weight per unit area increased, the influence of density rose to a maximum and then diminished, whereupon mean fibre volume became the main contributor to wool weight. For different positions on the body of individual sheep, the dependence of wool production per unit area on the fleece characters was found to be similar in the two strains. Fibre density had the major effect in determining the level of production, whereas the influences of staple length and fibre area were negligible.

Methods of analysis and the influence of fleece characters on unit area wool production of Romney lambs

1960 ◽  
Vol 11 (5) ◽  
pp. 851 ◽  
Author(s):  
AE Henderson ◽  
BI Hayman
Keyword(s):  
Unit Area ◽  
Fibre Length ◽  
Fibre Volume ◽  
Cross Sectional Area ◽  
The Body ◽  
Skin Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Wool Production ◽  
Fibre Number

Investigation has been made of the influence of fibre number per unit area (N), cross-sectional area of fibre (A), and fibre length (L), on wool production per unit area of skin (W). The influence of the compound characters fibre volume (V) and proportion of skin area occupied by fibre (0) has also been considered. Methods are given whereby the significance of the variation associated with any one of these interacting components can be assessed. Data from four groups of lambs were analysed, each group having been subjected to a different nutritional regime. Slightly more than three-quarters of the variation induced in W by these treatments was due to variation in L, with N and A having negligible effects. No evidence was found that the relative influence of the components changed with change in level of production. Differences in W between lambs on the same nutritional level were influenced almost equally by variation in N and L, with A again having a negligible effect. Of the variation in W between positions on lambs, approximately 50 per cent. was accounted for by variation in N, 40 per cent. by variation in A, and 10 per cent. by variation in L. Variation of the compound character O accounted for nearly 90 per cent. of the variation in W over the body.

The Four Components of the Nasal Valve

2003 ◽  
Vol 17 (2) ◽  
pp. 107-110 ◽  
Author(s):  
Philip Cole
Keyword(s):  
Cross Sectional Area ◽  
The Body ◽  
Isometric Contractions ◽  
Lateral Cartilage ◽  
Sectional Area ◽  
Nasal Valve ◽  
Cross Sectional ◽  
Airflow Resistance ◽  
Orifice Flow ◽  
Upper Lateral Cartilage

The nasal valve consists of four distinct airflow-resistive components. (i) The vestibule terminates in an airflow-resistive aperture between the septum and the caudal end of the upper lateral cartilage. Its cross-sectional area is stabilized by the cartilaginous structures and by inspiratory isometric contractions of alar dilator muscles. Its walls are devoid of erectile tissues that might otherwise affect its cross-sectional area and airflow resistance. By contrast, (ii) the bony entrance to the cavum is occupied by erectile tissues of both (iii) lateral (turbinate) and (iv) septal nasal walls that modulate the cross-sectional area of the airway and airflow resistance. The body of the cavum offers little resistance to airflow. Valve constrictions induce “orifice flow” of inspiratory air as it enters the body of the cavum, disrupting laminar characteristics and thereby enhancing exchanges with the nasal mucosa of heat, water, and contaminants. Acoustic rhinometric and rhinomanometric measurements show the sites, dimensions, and resistances of the valve constrictions and indicate that it is seldom necessary to extend septal and/or turbinate surgery far beyond the piriform aperture in the treatment of nasal obstruction.

Anatomy of the intestine of Ascaris suum: a three dimensional study with silicone rubber casts

1977 ◽  
Vol 55 (7) ◽  
pp. 1110-1117
Author(s):  
Robert P. Harpur
Keyword(s):  
Body Wall ◽  
Female Worm ◽  
Ascaris Suum ◽  
Three Dimensional ◽  
Cross Sectional Area ◽  
The Body ◽  
Sectional Area ◽  
Expansion Chamber ◽  
Cross Sectional ◽  
Posterior Intestine

To facilitate studies of the physiology of Ascaris suum the relations between the intestine and the other organs were investigated. The anterior intestine, which starts, with a thin-walled expansion chamber, is held by connective tissue and by the bellies of muscle cells. A coarctation of the intestine marks the junction of the anterior and midintestine and in the female this narrowing occurs near the genital pore. The midintestine lies free amongst the reproductive organs and terminates near the most posterior excursions of the ovaries and uteri in the female, and of the testis in the male. The posterior intestine is attached continuously, but not initially circumferentially, to the body wall. Relative lengths for the different parts of the female worm are given and microfil casts made in situ with both sexes yielded information about the relative volumes of the midintestine and posterior intestine. The coarctation is the narrowest pan of the intestine and the largest cross-sectional area is reached at the start of the posterior intestine. The attachments to the body wall indicate that the anterior and posterior intestine change length like an accordion when the muscles contract but the cross-sectional area of the lumen is decreased by dorsoventral compression.

scholarly journals PO-155 Comparison of effects of different exercise modes on rat gastrocnemius muscle

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Xiujuan Liu ◽  
Nianyun Zhang
Keyword(s):  
Body Weight ◽  
Protein Expression ◽  
Gastrocnemius Muscle ◽  
Exercise Group ◽  
Cross Sectional Area ◽  
The Body ◽  
Morphological Observation ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross

Objective   To explore the effects of different exercise patterns on gastrocnemius weight. Methods   Forty-eight SD rats were randomly divided into 4 groups, which were quiet control group (Con), continuous exercise group (CE), high-intensity intermittent exercise group (HIIT) and ladder exercise group (LE). After 8 weeks of exercise training, each group was anesthetized and samples were collected for testing. The body weight and gastrocnemius weight of each group were recorded. The cross-sectional area (CSA) of ​​gastrocnemius muscle was observed by HE staining. The levels of MSTN and insulin in serum were detected by ELISA. The expressions of MSTN, IGF1 and p70S6K in rat gastrocnemius muscle were detected by Western blot. Results Compared with group Con, the body weights of the three exercise groups were significantly lower, and the weight of the gastrocnemius muscles in group CE was significantly lower. Morphological observation of gastrocnemius showed that the cross-sectional area of ​​the gastrocnemius muscle in group CE was significantly decreased, compared with group Con, and the cross-sectional area of ​​the gastrocnemius muscle in group LE was significantly increased. There was no significant change in the cross-sectional area of ​​the gastrocnemius muscle in group HIIT. The ELISA results showed that serum GDF8 levels were significantly decreased in the three exercise groups compared with group Con, while the insulin levels were not significantly changed. Compared with group Con, the expression of GDF8 protein in the gastrocnemius muscle of the group LE was significantly decreased, while the protein expression of IGF1 and P70S6K was significantly increased. The protein expression of the gastrocnemius P70S6K in group CE was also significantly increased. Conclusions   Although the three exercise modes can significantly reduce the body weight of rats, only HIIT and LE improve the gastrocnemius muscle mass index. CE significantly reduced the body weight and cross-sectional area of ​​the gastrocnemius muscle. Although the protein expression of P70S6K was increased, there was no significant effect on the protein expression of GDF8 and IGF1. Ladder movement may increase the gastrocnemius cross-sectional area by reducing MSTN and increasing protein expression of IGF1 and P70S6K.

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