scholarly journals A juvenile cf. Edmontosaurus annectens (Ornithischia, Hadrosauridae) femur documents a poorly represented growth stage for this taxon

2019 ◽  
Vol 7 ◽  
Author(s):  
Andrew Farke ◽  
Eunice Yip
Keyword(s):  
Size Range ◽  
Femoral Shaft ◽  
Relative Increase ◽  
Slight Reduction ◽  
Femur Length ◽  
Hell Creek Formation ◽  
Juvenile Specimen ◽  
Juvenile Individual ◽  
Asymmetrical Shape ◽  
Distinct Separation

A nearly complete, but isolated, femur of a small hadrosaurid from the Hell Creek Formation of Montana is tentatively referred to Edmontosaurus annectens. At 28 cm long, the element can be classified as that from an “early juvenile” individual, approximately 24 percent of the maximum known femur length for this species. Specimens from this size range and age class have not been described previously for E. annectens. Notable trends with increasing body size include increasingly distinct separation of the femoral head and greater trochanter, relative increase in the size of the cranial trochanter, a slight reduction in the relative breadth of the fourth trochanter, and a relative increase in the prominence of the cranial intercondylar groove. The gross profile of the femoral shaft is fairly consistent between the smallest and largest individuals. Although an ontogenetic change from relatively symmetrical to an asymmetrical shape in the fourth trochanter has been suggested previously, the new juvenile specimen shows an asymmetric fourth trochanter. Thus, there may not be a consistent ontogenetic pattern in trochanteric morphology. An isometric relationship between femoral circumference and femoral length is confirmed for Edmontosaurus. Overall ontogenetic trends in the femur of Edmontosaurus are concordant with patterns seen in other Hadrosauridae, supporting a fairly conserved pattern of development for this element within the clade.

scholarly journals A juvenile cf. Edmontosaurus annectens (Ornithischia, Hadrosauridae) femur documents a poorly represented growth stage for this taxon

2018 ◽  
Author(s):  
Andrew Farke ◽  
Eunice Yip
Keyword(s):  
Size Range ◽  
Femoral Shaft ◽  
Relative Increase ◽  
Slight Reduction ◽  
Femur Length ◽  
Hell Creek Formation ◽  
Juvenile Specimen ◽  
Juvenile Individual ◽  
Asymmetrical Shape ◽  
Distinct Separation

A nearly complete, but isolated, femur of a small hadrosaurid from the Hell Creek Formation of Montana is tentatively referred to Edmontosaurus annectens. At 28 cm long, the element can be classified as that from an “early juvenile” individual, approximately 24 percent of the maximum known femur length for this species. Specimens from this size range and age class have not been described previously for E. annectens. Notable trends with increasing body size include increasingly distinct separation of the femoral head and greater trochanter, relative increase in the size of the cranial trochanter, a slight reduction in the relative breadth of the fourth trochanter, and a relative increase in the prominence of the cranial intercondylar groove. The gross profile of the femoral shaft is fairly consistent between the smallest and largest individuals. Although an ontogenetic change from relatively symmetrical to an asymmetrical shape in the fourth trochanter has been suggested previously, the new juvenile specimen shows an asymmetric fourth trochanter. Thus, there may not be a consistent ontogenetic pattern in trochanteric morphology. An isometric relationship between femoral circumference and femoral length is confirmed for Edmontosaurus. Overall ontogenetic trends in the femur of Edmontosaurus are concordant with patterns seen in other Hadrosauridae, supporting a fairly conserved pattern of development for this element within the clade.

Morphological channeling by structural constraint: convergence in styles of dwarfing and gigantism in Cerion, with a description of two new fossil species and a report on the discovery of the largest Cerion

Paleobiology ◽  
1984 ◽  
Vol 10 (2) ◽  
pp. 172-194 ◽  
Author(s):  
Stephen Jay Gould
Keyword(s):  
Size Range ◽  
Relative Increase ◽  
Spiral Growth ◽  
Structural Constraint ◽  
Maximum Width ◽  
Fossil Species ◽  
Normal Number ◽  
The Common

A survey of all Cerion taxa and geographic variants reveals that a distinctive shape—a narrowly spired “smokestack” shell more than three times higher than wide—occurs only in dwarfs and giants and never in the much more common populations of normal size. The smokestack shape evolved once in giants (in the newly described species C. excelsior from Great Inagua and Mayaguana—the largest of all Cerion), but at least seven and probably eight times independently in dwarfs. A study of complex allometric patterns in Cerion's ontogeny, and of covariance sets in growth, indicates that smokestacks can easily evolve in dwarfs and giants by the common route of relative increase in whorl number during an allometric phase that adds height but no width to the shell. (Giants simply add more whorls to a shell with whorls of normal size; dwarfs grow a normal number of whorls in a shell with small whorls and reduced maximum width.) This pathway is not open to Cerion of normal size, and the restriction of smokestacks to both extremes of the size range records a channel set by Cerion's invariant allometries and the geometry of spiral growth in general, not an immediate adaptation conferring special advantages via the elevated spire itself.

Fractionation Studies on Plasma of Normals and Patients with Laron Dwarfism and Hypopituitary Gigantism

1973 ◽  
Vol 51 (11) ◽  
pp. 845-852 ◽  
Author(s):  
R. M. Bala ◽  
J. C. Beck
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Size Range ◽  
Human Growth ◽  
Molecular Size ◽  
Relative Increase ◽  
Normal Serum ◽  
Main Peak ◽  
Relationship Of ◽  
The Relationship

The molecular size of immunoreactive human growth hormone (IR-HGH) in serum and the relationship of IR-HGH to sulfation factor (SF) require further investigation. Sera obtained from normal volunteers, patients with Laron-type dwarfism, and hypopituitary patients with gigantism were fractionated on large columns of Sephadex. The IR-HGH in normal serum was found in a molecular size range similar to extracted pituitary HGH (epHGH), as well as in a larger and a smaller molecular size. Laron dwarf plasma had a similar molecular size IR-HGH distribution when compared with normal serum. Sera from hypopituitary patients with gigantism showed an increased relative amount of small IR-HGH compared with normal serum. SF activity was recovered in normal serum but not in other sera fractions. SF activity appeared mainly in the molecular size range less than 17 000 and another peak was noted in the molecular size area greater than 55 000.This study further supports the existence of IR-HGH in a large and a small molecular size in normal serum. IR-HGH in Laron dwarf serum appears similar in molecular size to normal serum IR-HGH. The relative increase in small IR-HGH in hypopituitary patients with gigantism requires further investigation. SF activity appears in a molecular size different from epHGH in normal serum, the main peak being in a smaller molecular size area, with a lesser peak in a larger size area.

scholarly journals Bicondylar Angle and its Relation with Length and Neck Length of Human Femur

2018 ◽  
Vol 6 (1) ◽  
pp. 17-20
Author(s):  
Rabita Kharbuja ◽  
Rashmi Manjushree Adhikari ◽  
Anupama Shrestha
Keyword(s):  
Femoral Neck ◽  
Femoral Shaft ◽  
Point Of View ◽  
Neck Length ◽  
Femur Length ◽  
Femoral Length ◽  
Bipedal Gait ◽  
The Difference ◽  
Two Parameters ◽  
Two Sides

Introduction: Femoral bicondylar angle has immense importance from anatomical and clinical (forensic and anthropometric) point of view and is the characteristic feature of bipedal gait in humans. It is the angle between axis of femoral shaft and a line perpendicular to its transcondylar axis. The study was carried out to assess bicondylar angle and its relationship with femur length and neck length. Methods: Bicondylar angle, length, and neck length of available dry human femurs of unknown sex and age were measured using osteometric board and vernier caliper. Bicondylar angle between two sides were compared. Similarly, relation between the angle and femoral length and length of femoral neck was studied. Result: Bicondylar angle on right side was 8.65° (SD = 2.03) and on left side was 9.35° (SD = 2.05) and the different was not statistically significant (p = 0.08). On both sides, no significant correlation was found between bicondylar angle with femoral length and length of femoral neck. Conclusion: Mean bicondylar angle of right femur was 8.65° and that of left was 9.35° and the difference was not statistically significant. There was no significant relation between the angle and other two parameters.

scholarly journals Exploration of the coefficients of correlation of different segmental measurements with total length of disarticulated femoral bones: a systematic review

2017 ◽  
Vol 34 (02) ◽  
pp. 114-122
Author(s):  
L. Khanal ◽  
S. Shah ◽  
S. Koirala
Keyword(s):  
Distal Part ◽  
Femoral Shaft ◽  
Proximal Part ◽  
Femur Length ◽  
Coefficient Of Correlation ◽  
Total Length ◽  
Study Results ◽  
Forensic Case ◽  
Width Measurements ◽  
Highly Correlated

Abstract Introduction: In a forensic case with availability of femoral fragments, estimation of the total femoral length of the available segment is one of the steps used for estimating an inidividual's stature. This estimation will be more accurate if the segment has a high coefficient of correlation with the total length of the femur. This article reviews the coefficients of correlation of different segmental measurements with femur length. Materials and Methods: Seventeen articles were selected from PubMed, Google Scholar and other public research sharing sites. Articles with coefficients of correlation of segmental measurements with the total length of the femur were included in the study. Results and Discussion: Among the 17 articles, two were related to measurement of the proximal part of the femur only, one was concerned with femoral shaft measurement only, 7 focus on the distal part only, 3 concerned both proximal and distal parts, and 4 articles included all parts of the femur. Sample sizes varied from 50 to 2388 femur bones. The value of the coefficient of correlation (‘r’) was found to vary with respect to gender and nationality. The value of ‘r’ for several width measurements of the segments had a higher correlation among females compared to male individuals. Conclusion: Though segment 1 of the proximal part, segment 3 of the shaft, and the epicondylar and bicondylar breadths of the distal part of the femur are highly correlated with the total length of femur, an investigator should also consider of gender, race, ethnicity and environmental factors when choosing the femur segment that has the highest value of ‘r’.

Microtomy of spherical Al2O3 powders

1983 ◽  
Vol 41 ◽  
pp. 74-75
Author(s):  
E.J. Jenkins ◽  
D.S. Tucker ◽  
J.J. Hren
Keyword(s):  
Thin Film ◽  
Size Range ◽  
Particle Aggregation ◽  
Ion Milling ◽  
Thin Sections ◽  
Α Phase ◽  
Convenient Means ◽  
Van Der Waals Attraction ◽  
Negative Feature ◽  
Film Substrate

The size range of mineral and ceramic particles of one to a few microns is awkward to prepare for examination by TEM. Electrons can be transmitted through smaller particles directly and larger particles can be thinned by crushing and dispersion onto a substrate or by embedding in a film followed by ion milling. Attempts at dispersion onto a thin film substrate often result in particle aggregation by van der Waals attraction. In the present work we studied 1-10 μm diameter Al2O3 spheres which were transformed from the amprphous state to the stable α phase.After the appropriate heat treatment, the spherical powders were embedded in as high a density as practicable in a hard EPON, and then microtomed into thin sections. There are several advantages to this method. Obviously, this is a rapid and convenient means to study the microstructure of serial slices. EDS, ELS, and diffraction studies are also considerably more informative. Furthermore, confidence in sampling reliability is considerably enhanced. The major negative feature is some distortion of the microstructure inherent to the microtoming operation; however, this appears to have been surprisingly small. The details of the method and some typical results follow.

Microdiffraction Patterns of Small Metallic Particles II; Theoretical Analysis

1982 ◽  
Vol 40 ◽  
pp. 668-669
Author(s):  
A. Gómez ◽  
P. Schabes-Retchkiman ◽  
M. José-Yacamán ◽  
T. Ocaña
Keyword(s):  
Experimental Data ◽  
Electron Diffraction ◽  
Theoretical Analysis ◽  
Size Range ◽  
Dynamical Theory ◽  
Metallic Particles ◽  
Splitting Effect

The splitting effect that is observed in microdiffraction pat-terns of small metallic particles in the size range 50-500 Å can be understood using the dynamical theory of electron diffraction for the case of a crystal containing a finite wedge. For the experimental data we refer to part I of this work in these proceedings.

Electron Microscopy of the Shape of Small Metal Particles

1977 ◽  
Vol 35 ◽  
pp. 300-301
Author(s):  
M. Jose Yacaman
Keyword(s):  
Electron Microscopy ◽  
Metal Particle ◽  
Field Experiments ◽  
Size Range ◽  
Dark Field ◽  
Metal Particles ◽  
Bragg Condition ◽  
Crystal Particle ◽  
Small Metal Particle ◽  
Small Metal Particles

In the Study of small metal particles the shape is a very Important parameter. Using electron microscopy Ino and Owaga(l) have studied the shape of twinned particles of gold. In that work electron diffraction and contrast (dark field) experiments were used to produce models of a crystal particle. In this work we report a method which can give direct information about the shape of an small metal particle in the amstrong- size range with high resolution. The diffraction pattern of a sample containing small metal particles contains in general several systematic and non- systematic reflections and a two-beam condition can not be used in practice. However a N-beam condition produces a reduced extinction distance. On the other hand if a beam is out of the bragg condition the effective extinction distance is even more reduced.

Freeze-dried dispersions for automated SEM analysis of individual submicron airborne particulates

1992 ◽  
Vol 50 (1) ◽  
pp. 408-409
Author(s):  
Karen A. Katrinak ◽  
David W. Brekke ◽  
John P. Hurley
Keyword(s):  
Air Pollutants ◽  
Size Range ◽  
Sem Analysis ◽  
Individual Particle ◽  
Chemical Data ◽  
Particle Analysis ◽  
Bulk Analysis ◽  
Airborne Particulates ◽  
Freeze Dried ◽  
Individual Particle Analysis

Individual-particle analysis is well established as an alternative to bulk analysis of airborne particulates. It yields size and chemical data on a particle-by-particle basis, information that is critical in predicting the behavior of air pollutants. Individual-particle analysis is especially important for particles with diameter < 1 μm, because particles in this size range have a disproportionately large effect on atmospheric visibility and health.

Electron Microscopy in the Study of Natural Phytoplankton Assemblages

1985 ◽  
Vol 43 ◽  
pp. 620-623
Author(s):  
Linda Sicko-Goad
Keyword(s):  
Electron Microscopy ◽  
Aquatic Environment ◽  
Size Range ◽  
Physical Parameters ◽  
Specific Information ◽  
Phytoplankton Assemblages ◽  
Phytoplankton Productivity ◽  
Ecosystem Effects ◽  
Time Of Year ◽  
Species Specific

Although the use of electron microscopy and its varied methodologies is not usually associated with ecological studies, the types of species specific information that can be generated by these techniques are often quite useful in predicting long-term ecosystem effects. The utility of these techniques is especially apparent when one considers both the size range of particles found in the aquatic environment and the complexity of the phytoplankton assemblages.The size range and character of organisms found in the aquatic environment are dependent upon a variety of physical parameters that include sampling depth, location, and time of year. In the winter months, all the Laurentian Great Lakes are uniformly mixed and homothermous in the range of 1.1 to 1.7°C. During this time phytoplankton productivity is quite low.

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