Assessment of age at death by microscopy: Unbiased quantification of secondary osteons in femoral cross sections

2006 ◽  
Vol 159 ◽  
pp. S100-S103 ◽  
Author(s):  
Niels Lynnerup ◽  
Bruno Frohlich ◽  
Jørgen L. Thomsen
Keyword(s):  
Cross Sections ◽  
Age At Death ◽  
Secondary Osteons

scholarly journals Skeletochronology and Paleohistology of Hyposaurus rogersii (Crocodyliformes, Dyrosauridae) from the Early Paleogene of New Jersey, USA

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3067
Author(s):  
Rodrigo A. Pellegrini ◽  
Wayne R. Callahan ◽  
Alexander K. Hastings ◽  
David C. Parris ◽  
John D. McCauley
Keyword(s):  
Cross Sections ◽  
Fundamental System ◽  
Small Sample ◽  
Medullary Cavity ◽  
Mature Adult ◽  
Linear Path ◽  
Near Shore ◽  
Cyclical Growth ◽  
Early Paleogene ◽  
Secondary Osteons

The paleohistology of dyrosaurids is known from a small sample, despite being common fossils and representing a rare lineage of crocodylomorphs that survived the Cretaceous–Paleogene extinction. Their lifestyle has been inferred only from sections of the snout, vertebrae, partial femur, and tibia. To improve this, we conducted a skeletochronological and paleohistological study of midshaft cross-sections of both femora and humeri of a nearly complete Hyposaurus rogersii skeleton. We found lamellar-zonal bone that underwent remodeling, evidenced by resorption cavities and abundant secondary osteons within the primary periosteal cortex. The osteons, mostly longitudinally oriented and arranged in circular rows, often anastomose radially along a linear path, resembling radial rows. The medullary cavity is completely open, lacking trabeculae: endosteal deposition is limited to thin lamellae surrounding the cavity. Analysis of cyclical growth marks and the presence of an external fundamental system indicate the specimen was a fully mature adult 17–18 years of age. Comparison of the skeleton to others suggests sexual dimorphism and that it was female. The open medullary cavity, and no evidence for pachyosteosclerosis, osteosclerosis, osteoporosis, or pachyostosis indicate H. rogersii was not a deep diver or a fast swimmer in the open ocean but a near-shore marine ambush predator.

Age at death determination by means of femoral frequency of secondary osteons

1994 ◽  
Vol 9 (4) ◽  
pp. 329-337 ◽  
Author(s):  
G. Alciati ◽  
A. G. Drusini ◽  
M. Di Bacco ◽  
S. Pezzulli
Keyword(s):  
Age At Death ◽  
Death Determination ◽  
Secondary Osteons

scholarly journals Age-related changes of the histological structure in the limb bones of the domestic fowl

2021 ◽  
Vol 22 (2) ◽  
pp. 264-277
Author(s):  
N. S. Sukhanova
Keyword(s):  
Bone Tissue ◽  
Cross Sections ◽  
Domestic Fowl ◽  
Distal Part ◽  
Histological Structure ◽  
Limb Bones ◽  
Tissue Degeneration ◽  
Age Related ◽  
The Cross ◽  
Secondary Osteons

To assess the possibility of using the bird bone tissue as a recording structure, the histomorphological parameters of the bone tissue of laying hens of the lohman brown cross from the Kirov region (9 females and 1 male) aged from 1 month to 7.5 years were investigated. The comparison of the cross-sections of the humerus and femur, the phalanx of the toe and tibiotarsus of a 6-year-old individual revealed that tibiotarsus is the least susceptible to resorption. For further research in 7 individuals, this bone was divided into 3 sections (T1, T2 and T3), for each of which the description and measurement of the microstructure of the cross sections was carried out. It was revealed that the process of resorption of the periosteum begins at 2.5 years of age with the appearance of primary osteons. At the age of 3.5 years and later they penetrate into all layers of the periosteum, locating in chains between the lines of arrested growth. At 4.5 years of age, secondary osteons appear in the place of the primary ones, and areas of resorption are formed at the intersection of the Haversian and Volkmann canals. At the age of 5.5 years the medullary bone disappears from the bone cavity, rounded cavities filled with centripetal deposition of new bone tissue at the edges appear within the resorption sites. At the age of 6-7 years, bone tissue degeneration occurs, when the small cavities enlarge and merge into large resorption cavities, up to the complete resorption of the mesost. In the distal part of tibiotarsus (T3), a prolonged apposition of the layers of the periosteum and the latest resorption were recorded. The increase of the thickness of the periosteum and a decrease in the density of the osteon population was revealed by the morphometry of cross sections of the center of diaphysis. The sites of tibiotarsus where the age of females corresponds to the lines of growth layer of the periosteum were determined. The sites with additional lines of the arrested growth were demarcated. It was concluded that the periosteal layer of the domestic fowl tibiotarsus in the distal and proximal sites are suitable as a recording structure.

scholarly journals Estimating age at death from an archaeological bone sample – a preliminary study based on comparison of histomorphometric methods

2017 ◽  
Vol 80 (1) ◽  
pp. 37-55 ◽  
Author(s):  
Barbara Mnich ◽  
Janusz Skrzat ◽  
Krzysztof Szostek
Keyword(s):  
Cross Sections ◽  
Microscopic Analysis ◽  
Skeletal Remains ◽  
Biological Parameters ◽  
Age At Death ◽  
Methodological Issues ◽  
Structural Units ◽  
Preliminary Study ◽  
The Individual

Abstract The estimation of age at death is one of the most fundamental biological parameters, determined on skeletal remains in anthropological context. That is why, there is a constant need to improve applied methods. Histomorphometry, which uses microscopic analysis of bone tissue is suggested to be one alternative method. In general, this technique is based on measurements and the determination of the number and density of basic bone structural units, osteons. Osteon density is found to be related with age of the individual. The main goal of this research was to compare results of determined age at death, on the basis of ribs histology, comes from methods proposed by different authors. We analyzed ground cross sections of ribs from archeological origin. The presented methodology is simple in use and effective. Four different methods were tested (Stout and Paine 1992; Cho et al. 2002; Kim et al. 2007; Bednarek et al. 2009). The obtained age results were compared with each other as well as related to the age estimated by standard macroscopic method used in anthropology. Bednarek’s method is recognized to be the most supportive for anthropological analyzes. Methodological issues connected with grinding methodology and results interpretation are also presented. Hypothesis about interpopulation as well as histological and dimorphic differences were confirmed.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

An Analysis of Dissociation of Molecules in a High Resolution Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 486-487
Author(s):  
Mihir Parikh
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Sections ◽  
Resolving Power ◽  
Peak Intensity ◽  
Molecular Film ◽  
Resolution Electron ◽  
Dissociation Cross Section ◽  
High Resolution Electron Microscope ◽  
The Stability

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used

Surface ultrastructure of danazol treated rat endometrium: A SEM study

1983 ◽  
Vol 41 ◽  
pp. 556-557
Author(s):  
R.P. Apkarian ◽  
J.S. Sanfilippo
Keyword(s):  
Cross Sections ◽  
Reproductive Tract ◽  
Preliminary Investigation ◽  
Breast Disease ◽  
Distal Segment ◽  
Uterine Horn ◽  
Female Reproductive Tract ◽  
Ultrastructural Changes ◽  
Cycle Phase ◽  
Sprague Dawley

The synthetic androgen danazol, is an isoxazol derivative of ethisterone. It is utilized in the treatment of endometriosis, fibrocystic breast disease, and has a potential use as a contraceptive. A study was designed to evaluate the ultrastructural changes associated with danazol therapy in a rat model. The preliminary investigation of the distal segment of the rat uterine horn was undertaken as part of a larger study intended to elucidate the effects of danazol on the female reproductive tract.Cross-sections (2-3 mm in length) of the distal segment of the uterine horn from sixteen Sprague-Dawley rats were prepared for SEM. Ten rats in estrus served as controls and six danazol treated rats were noted to have alterations of the estrus cycle i.e. a lag in cycle phase or noncycling patterns. Specimens were fixed in 3% glutaraldehyde in 0.05M phosphate buffer containing CaCl2 at pH 7.0-7.4 and chilled to 4°C. After a brief wash in distilled water, specimens were passed through a graded series of ethanol, critical point dryed in CO2 from absolute ethanol, and coated with 6nm Au. Observations were made with an IS1-40 SEM operated at 15kV.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

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