Evaluation of corallite size as a criterion for species discrimination in favositids

1988 ◽  
Vol 62 (1) ◽  
pp. 32-40 ◽  
Author(s):  
D. J. Lee ◽  
J. P. A. Noble
Keyword(s):  
Cross Section ◽  
Statistical Treatment ◽  
Intraspecific Variability ◽  
West Point ◽  
Species Discrimination ◽  
Cross Sectional ◽  
The Best Approximation ◽  
Computer Based ◽  
The Mean ◽  
Upper Silurian

Of all the morphologic characters used in favositid taxonomy, corallite size has most frequently been given more weight than others because of its relative ease of measurement and because it has been generally believed to be less variable. This study evaluates the reliability of corallite size as a criterion by a statistical treatment of several populations of favositids in the Upper Silurian West Point Reef Complex in Gaspé, Québec. Calculation of corallite cross-sectional area was made feasible by computer-based image analysis which provides a quick and accurate measure of size. The present study shows that the mean of the largest 10 percent corallite areas in mature parts of colonies with a minimum sample size of 100 corallites per cross section is the best approximation available of mean adult corallite size.It is suggested that intraspecific variability of corallite size is often too large for this character to be used in practice, probably due to phenotypic plasticity. The same may be true of most other morphologic characters. In some cases, however, one or two characters remain invariate within a species and can be used diagnostically. The same characters may be extremely variable in other species.

Evaluation of corallite size as a criterion for species discrimination in favositids

1988 ◽  
Vol 62 (01) ◽  
pp. 32-40
Author(s):  
D. J. Lee ◽  
J. P. A. Noble
Keyword(s):  
Cross Section ◽  
Statistical Treatment ◽  
Intraspecific Variability ◽  
West Point ◽  
Species Discrimination ◽  
Cross Sectional ◽  
The Best Approximation ◽  
Computer Based ◽  
The Mean ◽  
Upper Silurian

Of all the morphologic characters used in favositid taxonomy, corallite size has most frequently been given more weight than others because of its relative ease of measurement and because it has been generally believed to be less variable. This study evaluates the reliability of corallite size as a criterion by a statistical treatment of several populations of favositids in the Upper Silurian West Point Reef Complex in Gaspé, Québec. Calculation of corallite cross-sectional area was made feasible by computer-based image analysis which provides a quick and accurate measure of size. The present study shows that the mean of the largest 10 percent corallite areas in mature parts of colonies with a minimum sample size of 100 corallites per cross section is the best approximation available of mean adult corallite size.It is suggested that intraspecific variability of corallite size is often too large for this character to be used in practice, probably due to phenotypic plasticity. The same may be true of most other morphologic characters. In some cases, however, one or two characters remain invariate within a species and can be used diagnostically. The same characters may be extremely variable in other species.

Follicle Microstructure and Innervation Vary between Pinniped Micro- and Macrovibrissae

2016 ◽  
Vol 88 (1) ◽  
pp. 43-58 ◽  
Author(s):  
Erin E. Mattson ◽  
Christopher D. Marshall
Keyword(s):  
Cross Section ◽  
Hair Shaft ◽  
Silver Stain ◽  
Cross Sectional ◽  
Aquatic Mammal ◽  
Pagophilus Groenlandicus ◽  
Histological Data ◽  
The Mean ◽  
Capsule Thickness ◽  
The Relationship

Histological data from terrestrial, semiaquatic, and fully aquatic mammal vibrissa (whisker) studies indicate that follicle microstructure and innervation vary across the mystacial vibrissal array (i.e. medial microvibrissae to lateral macrovibrissae). However, comparative data are lacking, and current histological studies on pinniped vibrissae only focus on the largest ventrolateral vibrissae. Consequently, we investigated the microstructure, medial-to-lateral innervation, and morphometric trends in harp seal (Pagophilus groenlandicus) vibrissal follicle-sinus complexes (F-SCs). The F-SCs were sectioned either longitudinally or in cross-section and stained with a modified Masson's trichrome stain (microstructure) or Bodian's silver stain (innervation). All F-SCs exhibited a tripartite blood organization system. The dermal capsule thickness, the distribution of major branches of the deep vibrissal nerve, and the hair shaft design were more symmetrical in medial F-SCs, but these features became more asymmetrical as the F-SCs became more lateral. Overall, the mean axon count was 1,221 ± 422.3 axons/F-SC and mean axon counts by column ranged from 550 ± 97.4 axons/F-SC (medially, column 11) to 1,632 ± 173.2 axons/F-SC (laterally, column 2). These values indicate a total of 117,216 axons innervating the entire mystacial vibrissal array. The mean axon count of lateral F-SCs was 1,533 ± 192.9 axons/ F-SC, which is similar to values reported in the literature for other pinniped F-SCs. Our data suggest that conventional studies that only examine the largest ventrolateral vibrissae may overestimate the total innervation by ∼20%. However, our study also accounts for variation in quantification methods and shows that conventional analyses likely only overestimate innervation by ∼10%. The relationship between axon count and cross-sectional F-SC surface area was nonlinear, and axon densities were consistent across the snout. Our data indicate that harp seals exhibit microstructural and innervational differences between their microvibrissae (columns 8-11) and macrovibrissae (columns 1-7). We hypothesize that this feature is conserved among pinnipeds and may result in functional compartmentalization within their mystacial vibrissal arrays.

Large Eddy Simulation in a Duct With Rounded Skewed Ribs

2005 ◽  
Author(s):  
Aroon K. Viswanathan ◽  
Danesh K. Tafti
Keyword(s):  
Heat Transfer ◽  
Large Eddy Simulation ◽  
Cross Section ◽  
Mean Flow ◽  
Cross Sectional ◽  
Square Duct ◽  
Eddy Simulation ◽  
Large Eddy ◽  
The Mean ◽  
Experimental Values

Results from Large Eddy Simulation (LES) of fully developed flow in a ribbed duct are presented with rib pitch-to-height ratio (P/e) is 10 and a rib height to hydraulic diameter ratio (e/Dh) is 0.1. Computations are carried out on a square duct with 45° ribs on the top and bottom walls arranged in a staggered fashion. The ribs have a rounded cross-section and are skewed at 45° to the main flow. The Reynolds number based on bulk velocity is 25,000. Mean flow and turbulent quantities, together with heat transfer and friction augmentation results are presented for a stationary case. The flow is characterized by a helical vortex behind each rib and a complementary cross-sectional secondary flow, both of which result from the angle of the rib with respect to the mean flow and result in a spanwise variation of the heat transfer. The mean flow, the turbulent quantities and the heat transfer in the duct show similar trends as in the duct with square cross-section ribs. However the results show that there is lesser friction in the ducts with rounded ribs. The overall heat transfer on the ribbed wall was augmented by 2.85 times that of a smooth duct, at the cost of friction which increases by a factor of 10. The computed values compare well with the experimental values.

scholarly journals Fibular Dimensions for Mandibular Reconstruction among Filipinos

2018 ◽  
Vol 32 (1) ◽  
pp. 2
Author(s):  
Nikkoh P. Muñoz ◽  
Adrian F. Fernando ◽  
Samantha S. Castañeda
Keyword(s):  
Cross Section ◽  
Cortical Thickness ◽  
Free Flaps ◽  
Cross Sectional Study ◽  
Mandibular Reconstruction ◽  
Sectional Study ◽  
Cross Sectional ◽  
The Mean ◽  
Bone Dimensions

Objective: To determine if the anatomic dimensions (length, cross-sectional width, cortical             thickness) of the Filipino fibula are ideal for mandibular reconstruction. Method: Design:           Cross-sectional study Setting:           Anatomy dissection laboratory Patients:         40 fibulas from 20 adult cadavers Results: Morphometric examination showed the mean length of the harvested fibulas was 33.5 cm. The mean horizontal (a-d) and vertical (b-c) widths of the proximal cross-section (point B) were 15.1 ± 0.28 mm and 9.9 ± 0.15 mm respectively. The mean horizontal (a-d) and vertical (b-c) widths of the distal cross-section (point D) were 15.4 ± 0.24 mm and 10.3 ± 0.49 mm respectively. The mean cortical thickness of the anterior (a), lateral (b), posterior (c) and medial (d) aspects of the proximal cross-section (point B) were 5.2 ± 0.1 mm, 3.2 ± 0.04 mm, 3.6 ± 0.01 mm, and 2.9 ± 0.06 mm respectively. The mean cortical thickness of the anterior (a), lateral (b), posterior (c) and medial (d) aspects of the distal cross-section (point D) were 5.1 ± 0.21 mm, 3.1 ± 0.11 mm, 3.5 ± 0.04 mm, and 2.9 ± 0.09 mm respectively. Conclusion: Our findings show that the Filipino fibulas studied have dimensions that are ideal for mandibular reconstruction. Keywords: Mandibular reconstruction, Fibula, Free Flaps, Fibular bone dimensions, Filipino

Aerodynamic behavior of wind turbines with polygonal cross- sectional tower

2021 ◽  
Author(s):  
Yong Chul Kim ◽  
Yukio Tamura
Keyword(s):  
Cross Section ◽  
Wind Turbines ◽  
Cross Sections ◽  
Lift Force ◽  
Circular Cross Section ◽  
Force Coefficient ◽  
Cross Sectional ◽  
The World ◽  
The Mean ◽  
Power Generation Systems

<p>Wind turbines are commonly used power generation systems around the world and their application is becoming increasingly widespread. Traditionally, circular‐cross‐section wind towers have been used, but recent upsizing of wind turbines has exposed weaknesses of these structures, including problems related to manufacturing and inadequate strength. Thus, the concept of site‐ assembled modular towers with polygonal cross‐sections such as octagonal and/or tetradecagonal has been proposed, but their wind‐resistant performances have not been clearly investigated. In the present study, the wind‐resistant performances of polygonal cross‐sectional towers were investigated through wind tunnel tests. It was thus found that the maximum force coefficient of the upper structure is larger than that of the tower, which makes the effect of cross‐sectional tower shape rather small. The mean and fluctuating lift force coefficients of a helical square cross‐sectional tower were quite small for cases of tower only and wind turbine.</p>

Mass Determination by Direct Measurement of Electron Scattering

1975 ◽  
Vol 33 ◽  
pp. 240-241
Author(s):  
M. K. Lamvik ◽  
A. V. Crewe
Keyword(s):  
Cross Section ◽  
Electron Scattering ◽  
Mass Density ◽  
Variable Mass ◽  
Scattering Cross Section ◽  
Mass Determination ◽  
Number Density ◽  
Cross Sectional ◽  
Thin Slice ◽  
Scattering Cross

If a molecule or atom of material has molecular weight A, the number density of such units is given by n=Nρ/A, where N is Avogadro's number and ρ is the mass density of the material. The amount of scattering from each unit can be written by assigning an imaginary cross-sectional area σ to each unit. If the current I0 is incident on a thin slice of material of thickness z and the current I remains unscattered, then the scattering cross-section σ is defined by I=IOnσz. For a specimen that is not thin, the definition must be applied to each imaginary thin slice and the result I/I0 =exp(-nσz) is obtained by integrating over the whole thickness. It is useful to separate the variable mass-thickness w=ρz from the other factors to yield I/I0 =exp(-sw), where s=Nσ/A is the scattering cross-section per unit mass.

A tilting high temperature gas reaction chamber for the JEM 7A T.E.M.

1978 ◽  
Vol 36 (1) ◽  
pp. 70-71
Author(s):  
Brian L. Rhoades
Keyword(s):  
Cross Section ◽  
Reaction Chamber ◽  
Objective Lens ◽  
Reduced Cross Section ◽  
Cross Sectional ◽  
Structural Investigations ◽  
Transmission Electron ◽  
Dynamic Experiments ◽  
Successful Design ◽  
Thermocouple Junction

A gas reaction chamber has been designed and constructed for the JEM 7A transmission electron microscope which is based on a notably successful design by Hashimoto et. al. but which provides specimen tilting facilities of ± 15° aboutany axis in the plane of the specimen.It has been difficult to provide tilting facilities on environmental chambers for 100 kV microscopes owing to the fundamental lack of available space within the objective lens and the scope of structural investigations possible during dynamic experiments has been limited with previous specimen chambers not possessing this facility.A cross sectional diagram of the specimen chamber is shown in figure 1. The specimen is placed on a platinum ribbon which is mounted on a mica ring of the type shown in figure 2. The ribbon is heated by direct current, and a thermocouple junction spot welded to the section of the ribbon of reduced cross section enables temperature measurement at the point where localised heating occurs.

Microstructure of laser-irradiated, conducting Kapton polyimide

1995 ◽  
Vol 53 ◽  
pp. 502-503
Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Surface ◽  
Cross Sectional ◽  
General Utility ◽  
Transmission Electron ◽  
Considerable Debate ◽  
Potential Applications

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.

Relationship of Sense of Coherence to Other Psychosocial Indices

2004 ◽  
Vol 20 (4) ◽  
pp. 227-236 ◽  
Author(s):  
Sara Holmberg ◽  
Anders Thelin ◽  
Eva-Lena Stiernström
Keyword(s):  
Social Support ◽  
Psychosocial Factors ◽  
Sense Of Coherence ◽  
Living Conditions ◽  
Strong Negative Correlation ◽  
Cross Sectional ◽  
Positive Correlation ◽  
Work Related ◽  
Job Demand ◽  
The Mean

Summary: The concept of “sense of coherence” (SOC) has been widely recognized since it was first introduced by Antonovsky. The originality and usefulness of the SOC scale and its relation to other psychosocial measures has been the subject of lively debate. The aim of this paper was to test for associations between SOC and work-related psychosocial factors (mainly the Job Demand-Control model), general living conditions, education, and social network factors. Cross-sectional data from a population-based sample of 1782 rural males from nine counties in Sweden were analyzed with a multiple regression technique. The subjects were occupationally active at inclusion and the mean age was 50 years (range 40-60). SOC was assessed with the original 29-item questionnaire. Psychosocial variables and lifestyle factors were assessed using questionnaires and structured interviews. The mean SOC among the subjects was 152.3 (standard deviation, 19.4). A strong negative correlation was found between SOC and job demand, whereas a positive correlation with job control was demonstrated. A positive correlation with general living conditions and with social support was also found. However, there was no correlation to education and occupation. Thus, SOC was shown to be strongly correlated to work-related psychosocial factors and social support, but independent of sociodemographic factors.

Age related volume of cadaver-prostates in Bangladesh

1970 ◽  
Vol 4 (2) ◽  
pp. 74-77
Author(s):  
Rukshana Ahmed ◽  
Shamim Ara
Keyword(s):  
Prostate Gland ◽  
Age Groups ◽  
Clinical Settings ◽  
Cross Sectional ◽  
Medical College ◽  
Age Related ◽  
Group A ◽  
Key Words Prostate ◽  
The Mean ◽  
Group B

Pathological changes in the prostate gland occur commonly with advancing age including inflammation, atrophy, hyperplasia and carcinoma and a change in volume is also evident. Estimation of volume of prostate may be useful in a variety of clinical settings. A cross-sectional descriptive study was designed to see the changes in volume of the prostate with advancing age and done in the Department of Anatomy, Dhaka Medical College, Dhaka from August 2006 to June 2007. The study was performed on 70 post-mortem human prostates collected from the unclaimed dead bodies that were under examination in the Department of Forensic Medicine, Dhaka Medical College, Dhaka. The samples were divided into three age groups; group A (10-20 years), group B (21-40 years) and group C (41-70 years). Volume of the sample was measured by using the ellipsoid formula. The mean ± SD volume of prostate was 7.68 ± 3.64 cm3 in group A, 10.61 ± 3.99 cm3 in group B and 15.40 ± 6.31 cm3 in group C. Mean difference in volume between group A and group C, group B and group C were statistically significant (p<0.001). Statistically significant positive correlation was found between age and volume of prostate (r = + 0.579, p < 0.001). Key Words: Prostate; volume; Bangladeshi. DOI: 10.3329/imcj.v4i2.6501Ibrahim Med. Coll. J. 2010; 4(2): 74-77

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