scholarly journals Secondary osteons scale allometrically in mammalian humerus and femur

2017 ◽  
Author(s):  
A. A. Felder ◽  
C. Phillips ◽  
H. Cornish ◽  
M. Cooke ◽  
J. R. Hutchinson ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Mammalian Species ◽  
Haversian Canal ◽  
Scaling Analysis ◽  
Cross Sectional ◽  
Spatial Dimensions ◽  
A Cell ◽  
Bone Cortex ◽  
Haversian Canals ◽  
Secondary Osteons

Intra-cortical bone remodelling is a cell-driven process that replaces existing bone tissue with new bone tissue in the bone cortex, leaving behind histological features called secondary osteons. While the scaling of bone dimensions on a macroscopic scale is well known, less is known about how the spatial dimensions of secondary osteons vary in relation to the adult body size of the species. We measured the cross-sectional area of individual intact secondary osteons and their central Haversian canals in transverse sections from 40 stylopodal bones of 39 mammalian species. Scaling analysis of our data shows that mean osteonal resorption area (negative allometry, exponent 0.23, R2 0.54, p < 0.005) and Haversian canal area (negative allometry, exponent 0.34, R2 0.45, p < 0.005) are significantly related to body mass, independent of phylogeny. This study is the most comprehensive of its kind to date, and allows us to describe overall trends in the scaling behaviour of secondary osteon dimensions, supporting the inference that osteonal resorption area may be limited by the need to avoid fracture in smaller mammalian species, but the need to maintain osteocyte viability in larger mammalian species.

scholarly journals Secondary osteons scale allometrically in mammalian humerus and femur

2017 ◽  
Vol 4 (11) ◽  
pp. 170431 ◽  
Author(s):  
A. A. Felder ◽  
C. Phillips ◽  
H. Cornish ◽  
M. Cooke ◽  
J. R. Hutchinson ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Body Mass ◽  
Mammalian Species ◽  
Haversian Canal ◽  
Scaling Analysis ◽  
Cross Sectional ◽  
Spatial Dimensions ◽  
A Cell ◽  
Bone Cortex ◽  
Secondary Osteons

Intra-cortical bone remodelling is a cell-driven process that replaces existing bone tissue with new bone tissue in the bone cortex, leaving behind histological features called secondary osteons. While the scaling of bone dimensions on a macroscopic scale is well known, less is known about how the spatial dimensions of secondary osteons vary in relation to the adult body size of the species. We measured the cross-sectional area of individual intact secondary osteons and their central Haversian canals in transverse sections from 40 stylopodal bones of 39 mammalian species (body mass 0.3–21 000 kg). Scaling analysis of our data shows that mean osteonal resorption area (negative allometry, exponent 0.23, R 2  0.54, p <0.005) and Haversian canal area (negative allometry, exponent 0.31, R 2  0.45, p <0.005) are significantly related to body mass, independent of phylogeny. This study is the most comprehensive of its kind to date, and allows us to describe overall trends in the scaling behaviour of secondary osteon dimensions, supporting the inference that the osteonal resorption area may be limited by the need to avoid fracture in smaller mammalian species, but the need to maintain osteocyte viability in larger mammalian species.

Mechanical Anisotropy of Individual Osteons in Bone Tissue at High Spatial Resolutions

2009 ◽  
Author(s):  
Davide Carnelli ◽  
Haimin Yao ◽  
Ming Dao ◽  
Pasquale Vena ◽  
Roberto Contro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cortical Bone ◽  
Mechanical Anisotropy ◽  
Haversian Canal ◽  
Maximum Penetration ◽  
Fundamental Units ◽  
Anisotropy Of Mechanical Properties ◽  
Penetration Depths ◽  
Secondary Osteons ◽  
Mineralized Collagen

Secondary osteons, the fundamental units of cortical bone, consist of cylindrical lamellar composites composed of mineralized collagen fibrils. Due to its lamellar structure, a multiscale knowledge of the mechanical properties of cortical bone is required to understand the biomechanical function of the tissue. In this light, nanoindentation tests were performed along the axial and transverse directions following a radial path from the Haversian canal to the osteonal edges. Different length scales are explored by means of indentations at different maximum penetration depths. Indentation moduli and hardness data were then interpreted in the context of the known microstructure. Results suggest that secondary osteons hierarchical structure is responsible for an observed length scale effect, homogenization phenomena and anisotropy of mechanical properties.

Form follows function: how muscle shape is regulated by work

2000 ◽  
Vol 88 (3) ◽  
pp. 1127-1132 ◽  
Author(s):  
Brenda Russell ◽  
Delara Motlagh ◽  
William W. Ashley
Keyword(s):  
Muscle Cell ◽  
Cell Shape ◽  
Force Production ◽  
Cardiac Cells ◽  
Cross Sectional Area ◽  
Dynamic Responses ◽  
Mechanical Activity ◽  
Sectional Area ◽  
Cross Sectional ◽  
A Cell

What determines the shape, size, and force output of cardiac and skeletal muscle? Chicago architect Louis Sullivan (1856–1924), father of the skyscraper, observed that “form follows function.” This is as true for the structural elements of a striated muscle cell as it is for the architectural features of a building. Function is a critical evolutionary determinant, not form. To survive, the animal has evolved muscles with the capacity for dynamic responses to altered functional demand. For example, work against an increased load leads to increased mass and cross-sectional area (hypertrophy), which is directly proportional to an increased potential for force production. Thus a cell has the capacity to alter its shape as well as its volume in response to a need for altered force production. Muscle function relies primarily on an organized assembly of contractile and other sarcomeric proteins. From analysis of homogenized cells and molecular and biochemical assays, we have learned about transcription, translation, and posttranslational processes that underlie protein synthesis but still have done little in addressing the important questions of shape or regional cell growth. Skeletal muscles only grow in length as the bones grow; therefore, most studies of adult hypertrophy really only involve increased cross-sectional area. The heart chamber, however, can extend in both longitudinal and transverse directions, and cardiac cells can grow in length and width. We know little about the regulation of these directional processes that appear as a cell gets larger with hypertrophy or smaller with atrophy. This review gives a brief overview of the regulation of cell shape and the composition and aggregation of contractile proteins into filaments, the sarcomere, and myofibrils. We examine how mechanical activity regulates the turnover and exchange of contraction proteins. Finally, we suggest what kinds of experiments are needed to answer these fundamental questions about the regulation of muscle cell shape.

scholarly journals Brucellosis in camel and human: Seroprevalence and associated risk factors in Amibara district of Afar region, Ethiopia

2021 ◽  
Author(s):  
Fekadu Gutema ◽  
Prof Kebede Amenu ◽  
Adugna Chalchisa ◽  
Prof Gezahegn Mamo
Keyword(s):  
Risk Factors ◽  
Close Contact ◽  
Mammalian Species ◽  
Raw Milk ◽  
Cross Sectional Study ◽  
Public Health Importance ◽  
Cross Sectional ◽  
North East ◽  
Afar Region ◽  
Associated Risk Factors

Abstract Background: Brucellosis is an important neglected zoonotic disease caused by infection with bacteria of the genus Brucella affecting different mammalian species including man. A cross-sectional study was conducted to estimate the seroprevalence of brucellosis in camels and human and its associated risk factors in Amibara district of Afar region, North east Ethiopia from October 2019 to May 2020Result: A total of 250 camel and 120 human sera were serially tested using the Rose Bengal Plate Test (RBPT), and Complement Fixation Test (CFT). The overall seroprevalence of camel brucellosis in the current study was 7.6% (95% CI: 4.9-11.56) using RBPT and 3.2% (95% CI: 1.63-6.2) by combined RBPT and CFT. In Human twelve (10%) of the collected sera were positive by RBPT among which only four of them (3.33%) were positive by CFT. The risk factors analysis indicated that, age, body condition, number of parity and abortion history were significantly associated with brucella seropositivity in camel(P≤0.05). In human, occupation and non-protective handling of dystocia cases showed apparent association with brucella seropositivity.Conclusion: The results of the present study indicated that, brucellosis is a common health problem in camel and human in Amibara district of Afar region. The public health importance of this disease is associated with raw milk consumption and close contact with the animals having history of recent abortion. Therefore, controlling the risk factors, establishing brucella diagnostic service in human clinics and hospitals, continuous social training with feedback assessments and overall implementing of One Health approach framework to attain optimal health for people and domestic animals in area are recommended to safeguard the health of society.

scholarly journals DON-induced changes in bone homeostasis in mink dams

2017 ◽  
Vol 61 (3) ◽  
pp. 357-362 ◽  
Author(s):  
Ewa Tomaszewska ◽  
Piotr Dobrowolski ◽  
Siemowit Muszyński ◽  
Krzysztof Kostro ◽  
Iwona Taszkun ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Bone Mineral ◽  
Wall Thickness ◽  
Vertical Wall ◽  
Control Group ◽  
Bone Homeostasis ◽  
Mineral Density ◽  
Cross Sectional ◽  
Final Body Weight ◽  
Induced Changes

AbstractIntroduction: The aim of the study was to investigate the mechanical and geometric properties as well as bone tissue and mineral density of long bones in mink dams exposed to deoxynivalenol (DON) since one day after mating, throughout gestation (ca. 46 d) and lactation to pelt harvesting. Material and Methods: Thirty clinically healthy multiparous minks (Neovison vison) of the standard dark brown type were used. After the mating, the minks were randomly assigned into two equal groups: nontreated control group and DON group fed wheat contaminated naturally with DON at a concentration of 1.1 mg·kg-1of feed. Results: The final body weight and weight and length of the femur did not differ between the groups. However, DON contamination decreased mechanical endurance of the femur. Furthermore, DON reduced the mean relative wall thickness and vertical wall thickness of the femur, while vertical cortical index, midshaft volume, and cross-sectional moment of inertia increased. Finally, DON contamination did not alter bone tissue density, bone mineral density, or bone mineral content, but decreased the values of all investigated structural and material properties. Conclusion: DON at applied concentration probably intensified the process of endosteal resorption, which was the main reason for bone wall thinning and the weakening of the whole bone.

Onlay Silicone and Hydroxyapatite-Tricalciumphosphate Composite (HAP-TCP) Blocks Interfere with Nasal Bone Growth in Rabbits

1995 ◽  
Vol 32 (4) ◽  
pp. 282-289
Author(s):  
Minoru Arakaki ◽  
Shunichi Yamashita ◽  
Mehmet Mutaf ◽  
Shinji Naito ◽  
Tohru Fujii
Keyword(s):  
Bone Tissue ◽  
Bone Growth ◽  
Nasal Bone ◽  
Growth Period ◽  
Blood Biochemistry ◽  
Hydroxyapatite Ceramic ◽  
Cross Sectional ◽  
Porous Hydroxyapatite ◽  
New Type ◽  
The Right

We investigated how a new type of synthetic porous hydroxyapatite ceramic (HAP-TCP) acts when it is implanted in growing membranous bone. Seventy-six New Zealand White infant male rabbits (4-week-olds) were used. Rabbits received HAP-TCP block or silicone block implantation in their right nasal bone. The left nasal bone was used for a sham. Serial or cross-sectional examinations by morphometry, radiology, blood biochemistry, and histology were carried out. Both the HAP-TCP and silicone groups exhibited no systemic growth disturbance in terms of morphometry and blood biochemistry. Dual energy x-ray absorptiometry (DEXA) revealed, however, a decrease in the bone mineral content (BMC) of the right nasal bone in the silicone group. Histology revealed a superior affinity of HAP-TCP to bone tissue than that of silicone. When a HAP-TCP block was implanted under the periosteum it bonded directly to bone tissue. However, sinking of the implants into the bone tissue were noted both in the HAP-TCP and the silicone groups in longitudinal observation. These results suggest that although HAP-TCP has superior affinity to bone tissue, this by itself is not enough sufficient reason to believe that HAP-TCP can be effectively applied during the growth period.

Statistical Thermodynamics and Surface Phase Transitions of Interacting Particles Adsorbed on One-Dimensional Channels Arranged in a Triangular Cross-Sectional Structure

2009 ◽  
Vol 150 ◽  
pp. 73-100 ◽  
Author(s):  
P.M. Pasinetti ◽  
F. Romá ◽  
J.L. Riccardo ◽  
A.J. Ramirez-Pastor
Keyword(s):  
Monte Carlo ◽  
Interaction Energy ◽  
Lattice Gas ◽  
Nearest Neighbor ◽  
Single Channel ◽  
Scaling Analysis ◽  
Surface Phase ◽  
Cross Sectional ◽  
One Dimensional ◽  
Sectional Structure

Monte Carlo simulations and finite-size scaling analysis have been carried out to study the critical behavior in a submonolayer lattice-gas, which mimics a nanoporous environment. In this model, one-dimensional chains of atoms were arranged in a triangular cross-sectional structure. Two kinds of lateral interaction energies have been considered: (1) wL, interaction energy between nearest-neighbor particles adsorbed along a single channel and (2) wT, interaction energy between particles adsorbed across nearest-neighbor channels. We focus on the case of repulsive transverse interactions (wT > 0), where a rich variety of structural orderings are observed in the adlayer, depending on the value of the parameters kBT/wT (kB being the Boltzmann constant) and wL /wT. For wL /wT = 0, successive planes are uncorrelated, the system is equivalent to the triangular lattice, and the well-known [ ] ordered phase is found at low temperatures and a coverage, , of 1/3 [2/3]. In the more general case (wL /wT  0), the competition between interactions along a single channel and the transverse coupling between sites in neighboring channels leads to a three-dimensional adsorbed layer. Consequently, the and structures “propagate” along the channels and new ordered phases appear in the adlayer. The influence of each ordered phase on adsorption isotherms, differential heat of adsorption and configurational entropy of the adlayer has been analyzed and discussed in the context of the lattice-gas theory. Finally, the Monte Carlo technique was combined with the recently reported free energy minimization criterion approach (FEMCA) [F. Romá et al.: Phys. Rev. B Vol. 68 (2003), art. no. 205407] to predict the critical temperatures of the surface-phase transformations occurring in the adsorbate. The excellent qualitative agreement between simulated data and FEMCA results allows us to interpret the physical meaning of the mechanisms underlying the observed transitions.

scholarly journals Medium- and large-sized mammal composition in the Chapada dos Veadeiros National Park and adjacent areas, state of Goiás, Brazil

2019 ◽  
Vol 59 ◽  
pp. e20195942 ◽  
Author(s):  
Átilla Colombo Ferreguetti ◽  
Isadora Cristina Motta Lessa ◽  
Emerson Monteiro Vieira ◽  
André Almeida Cunha ◽  
Helena Godoy Bergallo
Keyword(s):  
Species Composition ◽  
National Park ◽  
Mammalian Species ◽  
Scaling Analysis ◽  
Large Mammals ◽  
Conservation Units ◽  
Mammal Species ◽  
The Difference ◽  
Dry And Rainy Seasons

The Cerrado is the second largest Brazilian biome and only 2.8% is represented by protected areas. Considering the relevance of the Cerrado and Conservation Units in preserving the mammalian diversity, we provided the first assessment of the diversity of medium- and large-sized mammal species in the Chapada dos Veadeiros National Park (CVNP) and surroundings. We tested the effectiveness of the CVNP by assessing the difference in species composition within the park and its surroundings. We sampled CVNP in the rainy (October-December 2013) and dry seasons (March-June 2014) in order to characterize the seasonality within the community. We selected 36 sampling sites to evaluate the composition of the medium and large mammals in the CVNP and its surroundings, 18 in the CVNP and 18 in the park surroundings. We ordered mammalian composition and frequency of individuals data by using a Non-metric Multidimensional Scaling analysis (NMDS). We assessed the effect of season (dry and rainy seasons) and locality (within the CVNP and surroundings) on mammalian species richness with a two-way analysis of variance (Two-way ANOVA). We recorded 23 species, 13 within the CVNP and 17 species in its surroundings. Composition and frequency of records differed between dry and rainy seasons, with higher richness in the rainy season. Species’ composition and the frequency of records were also different between within the CVNP and its surroundings, with higher richness in the surroundings. These results provide information for the increase of the knowledge of mammalian ecology but also is useful as a tool for future strategies to the conservation of these species. More attention should be given to the monitoring of these species in the long term because this area still harbor some viable populations.

scholarly journals Bone tissue amount related to upper incisors inclination

2013 ◽  
Vol 84 (2) ◽  
pp. 279-285 ◽  
Author(s):  
Ana Carla Raphaelli Nahás-Scocate ◽  
Aluana de Siqueira Brandão ◽  
Mayara Paim Patel ◽  
Michel Eli Lipiec-Ximenez ◽  
Israel Chilvarquer ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Pearson Correlation ◽  
Cervical Region ◽  
Apical Region ◽  
Middle Region ◽  
Central Incisor ◽  
Cross Sectional ◽  
Strong Linear Correlation ◽  
The Mean ◽  
The Relationship

ABSTRACT Objective: To evaluate the amount of buccal and lingual supporting bone tissue of 60 upper central incisors and the relationship with their inclination. Materials and Methods: Thirty healthy adult patients with no previous orthodontic treatment were evaluated using cone-beam computed tomography. Cross-sectional views were analyzed to check the amount of the bone tissue on the cervical (cervical buccal thickness/CBT; lingual/CLT), middle (middle buccal thickness/MBT; lingual/MLT), and apical regions (apical buccal thickness/ABT; lingual/ALT). The Pearson correlation, linear regression, and analysis of variance tests were used (P &lt; .05). Results: The values of ABT of both teeth (11, right upper central incisor; 21, left upper central incisor) were significantly increased with the increase in the angle between the axis of the upper central incisor and the palatal plane (1/PP) (tooth 11 P  =  .034; tooth 21 P  =  .009), yet without a strong linear correlation. At the buccal and lingual surfaces, the mean apical supporting bone tissue was significantly greater than the other areas, and the middle region significantly greater than the cervical (P &lt; .001). Conclusions: For both surfaces (buccal and lingual), the amount of bone tissue in the apical region was significantly higher than the middle and cervical regions, and the middle region was significantly higher than the cervical region. In relation to the upper central incisor's inclination, the higher the 1/PP the higher was ABT. However, the coefficient values for both teeth were low.

Sign in / Sign up

Export Citation Format

Share Document