Comparative Analysis of 3-D Trabecular Bone Architecture: Applications to Locomotor Reconstruction in Fossil Primates

这个项目的主要目标是测量骨小梁的重要特征--在骨骼长骨末端发现的海绵组织。 研究人员希望测量灵长类动物之间骨小梁结构的变化与体重和运动的关系，并使用计算模型确定这种变化的机械后果。 骨小梁由复杂的棒和板互连网络组成，在骨质疏松症所致的衰老和骨丢失研究中受到了大量关注，但物理人类学家和比较解剖学家的关注相对较少。 许多因素，如行为，身体大小，性别，遗传和发展可能发挥重要作用，在决定骨小梁结构的成年动物。 本项目将通过研究三个重要问题来研究其中的一些因素：（1）灵长类动物物种内和物种间的骨小梁结构如何变化，以及这种变化与体型和性别的关系是什么？(2)骨小梁结构是否反映运动行为和运动期间不同的肢体使用（例如，在跳跃或手臂摆动）？以及（3）松质骨的弹性特性如何随身体大小、运动模式和肢体元素而变化？高分辨率的x射线计算机断层扫描将用于收集从肱骨和股骨的数据，这些数据来自不同的现存和最近灭绝的灵长类动物样本，大小从鼠狐猴到大猩猩不等。 将分析骨特征，如体积、厚度、数量、形状、互连性和方向。 将使用微观力学有限元模型通过模拟实验压缩测试来计算体积的弹性性能。 利用骨的结构特性和弹性常数，分析体重、骨结构和计算的力学特性之间的关系。该项目的智力价值包括更好地理解生理和行为因素对骨结构的作用。 它不仅将拓宽对骨生物学和骨结构变异的理解，而且还将产生重建已灭绝灵长类动物古生物学所需的比较数据。该项目也代表了一个跨-宾夕法尼亚州立大学的物理人类学家和荷兰埃因霍温科技大学的生物力学工程师之间的学科国际合作，研究人员的各种专业知识将用于回答与灵长类动物解剖学、功能形态学、骨生物学和人类健康相关的骨生物学问题。 该项目的更广泛影响包括制作一个大型比较数据集，将纳入人类学课程，用于培训体质人类学本科生和研究生。 CT数据的副本也将提供给出借博物馆的馆长，以便存档供其他科学家使用，并可能用于互动式计算机博物馆展览。 该项目的结果肯定会对理解人类骨骼疾病如骨质疏松症产生影响。

The principal goal of this project is to measure important features of trabecular bone -- the spongy tissue found inside the ends of the long bone of the skeleton. The investigators want to measure the variation of trabecular bone structure across primates in relation to body mass and locomotion and to determine the mechanical consequences of that variation using computational models. Trabecular bone, which is made up of a complex interconnected network of rods and plates, has received a significant amount of attention in studies of aging and bone loss due to osteoporosis, but comparatively little attention from physical anthropologists and comparative anatomists. Many factors such as behavior, body size, sex, genetics, and development may play important roles in determining the structure of trabecular bone in adult animals. This project will investigate some of these factors by looking at three important questions: (1) how does trabecular structure vary within and between primate species and what is the relationship of this variation to body size and sex? (2) does trabecular bone structure reflect locomotor behaviors and differential limb usage during locomotion (e.g., in leaping or arm swinging)? and (3) how do the elastic properties of trabecular bone vary across body size, locomotor mode, and limb element?High-resolution x-ray computed tomography will be used to collect data from the humerus and femur for a diverse sample of living and recently extinct primates ranging in size from mouse lemur to gorilla. Bone features such as volume, thickness, number, shape, interconnectedness, and orientation will be analyzed. Micromechanical finite element models will be used to calculate the elastic properties of the volumes by simulating experimental compression tests. Using the bone architectural properties and elastic constants, the relationships among body mass, bone structure and the calculated mechanical properties will be analyzed.The intellectual merits of this project include producing a better understanding of the role of physiological and behavioral factors on bone structure. It will not only broaden understanding of bone biology and bone structural variation, but will also produce the comparative data necessary to reconstruct the paleobiology of extinct primates.This project also represents a cross-disciplinary international collaboration between physical anthropologists at Penn State University and a biomechanical engineer at Eindhoven University of Technology in the Netherlands in which the varied expertise of the researchers will be used to answer questions about bone biology that have relevance to primate anatomy, functional morphology, bone biology, and human health. The broader impacts of the project include the production of a large comparative dataset that will be implemented into the anthropological curriculum and used to train undergraduate and graduate students in physical anthropology. Copies of the CT data also will be given to the curators of the lending museums to be archived for use by other scientists and potentially to be used for interactive computer-based museum exhibits. The results of this project will certainly have implications for understanding human skeletal disorders such as osteoporosis.