Rib kinematics and intercostal muscle function in amniotes

呼吸似乎是我们做的最简单的事情之一，但实际上胸腔的结构和运动是非常复杂的。肋骨和相关肌肉（肋间肌）有助于人类和其他动物的呼吸，但肋骨和肋间肌的确切呼吸活动几个世纪以来一直存在争议。为什么很难从这些肌肉的结构和与肋骨的连接来推断它们的活动呢？答案在于：(1)肋形的三维复杂性；(2)呼吸过程中肋骨运动的三维复杂性；(3)肋间肌的三维复杂性；(4)以上所有的变化，从上到下，从胸腔的前到后。对狗和人类进行了数十年的研究，终于对这些哺乳动物的呼气和吸气有了坚实的了解，但这项工作一直缓慢而艰苦。现在，一种新的3D x射线技术——x射线运动形态重建技术（XROMM）刚刚问世，它将极大地加快对活体动物骨骼形状和骨骼运动数据的收集。在这个项目中，xrom将被用于确定七个物种的三维肋骨形状、三维肋骨运动和肋间肌功能：三种蜥蜴、两种鸟类、一条短吻鳄和一条鳄鱼。选择这些动物是因为它们表现出不同的肋骨形状、肋骨关节形态、体型和运动行为（游泳、跑步和飞行）。xrom的出现将使这七个新物种有可能添加到目前仅有的两个物种的知识中，所有这些都将在短短三年内完成。在未来，这项工作的结果可用于重建灭绝动物的呼吸系统，特别是与有争议的恐龙呼吸机制相关。该项目包括为一名博士后和一名博士生提供跨学科培训，为K-12教育做出贡献，增加代表性不足群体的参与，并加强科学基础设施。博士后和研究生将通过与工程、计算机科学和计算与可视化中心的合作伙伴进行互动，获得跨学科的培训。博士后和研究生将领导具体项目，指导本科生研究人员，并与普罗维登斯公立学校的K-12教师合作。在普罗维登斯公立学校系统中，超过80%的学生来自代表性不足的群体，超过80%的学生有资格享受免费或减价午餐。科学家们将与K-12教师合作，开发并提供课程和项目，向学生传授动物运动、生物力学和xrom等科学方法。为了加强科学基础设施，xrom技术将得到改进，并开发新的软件来简化数据分析。所有的硬件和软件创新都是公开的，并且可以通过同事（通过NSF研究协调网络和www.xromm.org）获得。研究产生的完整元数据将立即通过公共在线数据库（xromm.ccv.brown.edu/webportal/）发布。元数据发布允许同事查看数据集的内容并提出合作建议。出版后或10年后（以较早者为准），所有数据将向公众公布。

Breathing seems like one of the simplest things we do, but actually the structures and motions of the rib cage are enormously complex. Ribs and associated muscles (the intercostal muscles) contribute to breathing in humans and other animals, but the exact respiratory actions of the ribs and intercostal muscles have been controversial for centuries. Why is it so difficult to infer the actions of these muscles from their structure and attachments to the ribs? The answer lies in: (1) the 3D complexity of rib shape; (2) the 3D complexity of rib motion during breathing; (3) the 3D complexity of intercostal muscles; and (4) variation in all of the above from top to bottom and front to back of the rib cage. Decades of work on dogs and humans have finally yielded a solid understanding of exhalation and inhalation in these mammals, but the work has been slow and laborious. Now a new 3D X-ray technology, X-ray Reconstruction of Moving Morphology (XROMM), has just become available and will vastly speed up the collection of data on bone shape and bone motion in living animals. In this project, XROMM will be used to determine 3D rib shape, 3D rib motion, and intercostal muscle function in seven species: three lizards, two birds, an alligator, and a crocodile. These animals were selected because they show a diverse spectrum of rib shapes, rib joint morphologies, body forms, and locomotor behaviors (swimming, running and flying). The advent of XROMM will make it possible to add these seven new species to the current knowledge of just two species, all within just three years. In the future, the results of this work can be used to reconstruct the respiratory system of extinct animals, with particular relevance to the controversial respiratory mechanisms of dinosaurs.The project includes interdisciplinary training for a Postdoctoral Fellow and a doctoral student, contributions to K-12 education, to increasing participation of underrepresented groups, and to enhancing scientific infrastructure. The postdoc and graduate student will gain interdisciplinary training through interactions with our collaborators in Engineering, Computer Science, and the Center for Computation and Visualization. The postdoc and graduate student will take the lead on specific projects, mentor undergraduate researchers, and work with K-12 teachers from the Providence Public Schools. More than 80% of students in the Providence Public School system are from underrepresented groups and more than 80% qualify for free or reduced cost lunch. In cooperation with K-12 teachers, the scientists will develop and deliver lessons and projects to teach the students about animal motion, biomechanics, and scientific methods such as XROMM. Toward enhancing scientific infrastructure, the XROMM technology will be improved and new software developed to simplify the data analysis. All hardware and software innovations are made public and are available to colleagues (through an NSF Research Coordination Network and via www.xromm.org). The complete metadata generated by the study will be published immediately through a public online database (xromm.ccv.brown.edu/webportal/). Metadata publication allows colleagues to see the contents of the data sets and suggest collaborations. After publication or after 10 years, whichever is earlier, all data will be made public.