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1. Limb and hip morphology of two African colobine monkeys and its relationship to the mechanics of leaping and bounding locomotion

   https://doi.org/10.1002/ajpa.24839  

   Polvadore, Taylor ; McGraw, W. Scott ; Daegling, David J. ( August 2023 , American Journal of Biological Anthropology)

   Although a bounding gait is practiced by a diversity of animals, the morphological characteristics, kinematics, and energetics associated with this locomotor form remain poorly understood. This study focuses on the locomotor anatomy of two species of African colobine monkeys (Piliocolobus badius, a leaper, andColobus polykomos, a leaper–bounder) in an effort to assess if bounding should be considered a unique primate locomotor category or is better viewed as a behavior on a leaping continuum.

   A total of 53 femora, 28 humeri, and 45 ossa coxae from the two species provide comparative morphological data. Free‐body models of bounding and leaping are presented to characterize loading conditions. Species differences in morphometric traits are evaluated via parametric and nonparametric tests (i.e., analysis of variance, resampling).

   C. polykomosexhibits traits that align more closely with putative leaping specializations when compared toP. badius(e.g., large femoral head, long femur, low femoral neck angle), while also possessing certain traits that are not (e.g., long femoral neck and reduced relative femoral robusticity). Consequently,C. polykomoslikely experiences absolutely greater joint forces at the hip and higher bending at the femoral neck both when it leaps and bounds, given equivalent accelerations in bounding and leaping.

   Bounding is best described as a form of low‐acceleration leaping. If bounding has lower acceleration requirements relative to leaping,C. polykomosachieves locomotor competence with less energy, relatively smaller bending moments, and reduced joint forces.

    

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2. Beyond Dimorphism: Body Size Variation Among Adult Orangutans Is Not Dichotomous by Sex

   https://doi.org/10.1093/icb/icad015  

   Kralick, Alexandra E. ; O'Connell, Caitlin A. ; Bastian, Meredith L. ; Hoke, Morgan K. ; Zemel, Babette S. ; Schurr, Theodore G. ; Tocheri, Matthew W. ( April 2023 , Integrative And Comparative Biology)

   Among extant great apes, orangutans are considered the most sexually dimorphic in body size. However, the expression of sexual dimorphism in orangutans is more complex than simply males being larger than females. At sexual maturity, some male orangutans develop cheek pads (flanges), while other males remain unflanged even after becoming reproductively capable. Sometimes flange development is delayed in otherwise sexually mature males for a few years. In other cases, flange development is delayed for many years or decades, with some males even spending their entire lifespan as unflanged adults. Thus, unflanged males of various chronological ages can be mistakenly identified as “subadults.” Unflanged adult males are typically described as “female-sized,” but this may simply reflect the fact that unflanged male body size has only ever been measured in peri-pubescent individuals. In this study, we measured the skeletons of 111 wild adult orangutans (Pongo spp.), including 20 unflanged males, 45 flanged males, and 46 females, resulting in the largest skeletal sample of unflanged males yet studied. We assessed long bone lengths (as a proxy for stature) for all 111 individuals and recorded weights-at-death, femoral head diameters, bi-iliac breadths, and long bone cross-sectional areas (CSA) (as proxies for mass) for 27 of these individuals, including seven flanged males, three adult confirmed-unflanged males, and three young adult likely-unflanged males. ANOVA and Kruskal–Wallis tests with Tukey and Dunn post-hoc pairwise comparisons, respectively, showed that body sizes for young adult unflanged males are similar to those of the adult females in the sample (all P ≥ 0.09 except bi-iliac breadth), whereas body sizes for adult unflanged males ranged between those of adult flanged males and adult females for several measurements (all P < 0.001). Thus, sexually mature male orangutans exhibit body sizes that range from the female end of the spectrum to the flanged male end of the spectrum. These results exemplify that the term “sexual dimorphism” fails to capture the full range of variation in adult orangutan body size. By including adult unflanged males in analyses of body size and other aspects of morphology, not as aberrations but as an expected part of orangutan variation, we may begin to shift the way that we think about features typically considered dichotomous according to biological sex.

    

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3. Influences of passive intervertebral range of motion on cervical vertebral form

   https://doi.org/10.1002/ajpa.24044  

   Grider‐Potter, Neysa ; Nalley, Thierra K. ; Thompson, Nathan E. ; Goto, Ryosuke ; Nakano, Yoshihiko ( March 2020 , American Journal of Physical Anthropology)

   The cervical spine is the junction between the head and trunk, and it therefore facilitates head mobility and stability. The goal of this study is to test several predictions regarding cervical morphology and intervertebral ranges of motion.

   Intervertebral ranges of motion for 12 primate species were collected via radiographs or taken from the literature. Morphometric data describing functionally relevant aspects of cervical vertebral morphology were obtained from museum specimens representing these species. We tested for correlations between intervertebral movement and vertebral form using phylogenetic generalized least‐squares regression.

   Results demonstrate limited support for the hypothesis that range of motion (ROM) is influenced by cervical vertebral morphology. Few morphological variables correlate with ROM and no relationship is consistently significant across cervical joints.

   These results indicate that the relationship between vertebral morphology and joint ranges of motion is, at most, weak, providing little support the use of bony morphology to reconstruct axial mobility in fossil specimens. Future work should investigate the role of soft tissues in vertebral joint stability.

    

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4. Arthritic Periosteal Tissue From Joint Replacement Surgery: A Novel, Autologous Source of Stem Cells

   https://doi.org/10.5966/sctm.2013-0056  

   Chang, Hana ; Docheva, Denitsa ; Knothe, Ulf_R ; Knothe_Tate, Melissa_L ( January 2014 , Stem Cells Translational Medicine)

   The overarching aim of this study is to assess the feasibility of using periosteal tissue from the femoral neck of arthritic hip joints, usually discarded in the normal course of hip replacement surgery, as an autologous source of stem cells. In addition, the study aims to characterize intrinsic differences between periosteum-derived cell (PDC) populations, isolated via either enzymatic digestion or a migration assay, including their proliferative capacity, surface marker expression, and multipotency, relative to commercially available human bone marrow-derived stromal cells (BMSCs) cultured under identical conditions. Commercial BMSCs and PDCs were characterized in vitro, using a growth assay, flow cytometry, as well as assay of Oil Red O, alizarin red, and Safranin O/Fast Green staining after respective culture in adipo-, osteo-, and chondrogenic media. Based on these outcome measures, PDCs exhibited proliferation rate, morphology, surface receptor expression, and multipotency similar to those of BMSCs. No significant correlation was observed between outcome measures and donor age or diagnosis (osteoarthritis [OA] and rheumatoid arthritis [RA], respectively), a profound finding given recent rheumatological studies indicating that OA and RA share not only common biomarkers and molecular mechanisms but also common pathophysiology, ultimately resulting in the need for joint replacement. Furthermore, PDCs isolated via enzymatic digestion and migration assay showed subtle differences in surface marker expression but otherwise no significant differences in proliferation or multipotency; the observed differences in surface marker expression may indicate potential effects of isolation method on the population of cells isolated and/or the behavior of the respective isolated cell populations. This study demonstrates, for the first time to our knowledge, the feasibility of using arthritic tissue resected during hip replacement as a source of autologous stem cells. In sum, periosteum tissue that is resected with the femoral neck in replacing the hip represents an unprecedented and, to date, unstudied source of stem cells from OA and RA patients. Follow-up studies will determine the degree to which this new, autologous source of stem cells can be banked for future use.

    

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5. FOVEA: a new program to standardize the measurement of foveal pit morphology

   https://doi.org/10.7717/peerj.1785  

   Moore, Bret A. ; Yoo, Innfarn ; Tyrrell, Luke P. ; Benes, Bedrich ; Fernandez-Juricic, Esteban ( April 2016 , PeerJ)

   The fovea is one of the most studied retinal specializations in vertebrates, which consists of an invagination of the retinal tissue with high packing of cone photoreceptors, leading to high visual resolution. Between species, foveae differ morphologically in the depth and width of the foveal pit and the steepness of the foveal walls, which could influence visual perception. However, there is no standardized methodology to measure the contour of the foveal pit across species. We present here FOVEA, a program for the quantification of foveal parameters (width, depth, slope of foveal pit) using images from histological cross-sections or optical coherence tomography (OCT). FOVEA is based on a new algorithm to detect the inner retina contour based on the color variation of the image. We evaluated FOVEA by comparing the fovea morphology of two Passerine birds based on histological cross-sections and its performance with data from previously published OCT images. FOVEA detected differences between species and its output was not significantly different from previous estimates using OCT software. FOVEA can be used for comparative studies to better understand the evolution of the fovea morphology in vertebrates as well as for diagnostic purposes in veterinary pathology. FOVEA is freely available for academic use and can be downloaded at:http://estebanfj.bio.purdue.edu/fovea.

    

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