The intervertebral disc (IVD) has long been considered unique to mammals. Palaeohistological sampling of 17 mostly extinct clades across the amniote tree revealed preservation of different ...intervertebral soft tissue types (cartilage, probable notochord) seen in extant reptiles. The distribution of the fossilised tissues allowed us to infer the soft part anatomy of the joint. Surprisingly, we also found evidence for an IVD in fossil reptiles, including non-avian dinosaurs, ichthyosaurs, plesiosaurs, and marine crocodiles. Based on the fossil dataset, we traced the evolution of the amniote intervertebral joint through ancestral character state reconstruction. The IVD evolved at least twice, in mammals and in extinct diapsid reptiles. From this reptilian IVD, extant reptile groups and some non-avian dinosaurs independently evolved a synovial ball-and-socket joint. The unique birds dorsal intervertebral joint evolved from this dinosaur joint. The tuatara and some geckos reverted to the ancestral persisting notochord.
Developing automated methods to efficiently process large volumes of point cloud data remains a challenge for three-dimensional (3D) plant phenotyping applications. Here, we describe the development ...of machine learning methods to tackle three primary challenges in plant phenotyping: lamina/stem classification, lamina counting, and stem skeletonization. For classification, we assessed and validated the accuracy of our methods on a dataset of 54 3D shoot architectures, representing multiple growth conditions and developmental time points for two Solanaceous species, tomato (
) and
Using deep learning, we classified lamina versus stems with 97.8% accuracy. Critically, we also demonstrated the robustness of our method to growth conditions and species that have not been trained on, which is important in practical applications but is often untested. For lamina counting, we developed an enhanced region-growing algorithm to reduce oversegmentation; this method achieved 86.6% accuracy, outperforming prior methods developed for this problem. Finally, for stem skeletonization, we developed an enhanced tip detection technique, which ran an order of magnitude faster and generated more precise skeleton architectures than prior methods. Overall, our improvements enable higher throughput and accurate extraction of phenotypic properties from 3D point cloud data.
Fossil evidence points to an African origin of Homo sapiens from a group called either H. heidelbergensis or H. rhodesiensis. However, the exact place and time of emergence of H. sapiens remain ...obscure because the fossil record is scarce and the chronological age of many key specimens remains uncertain. In particular, it is unclear whether the present day 'modern' morphology rapidly emerged approximately 200 thousand years ago (ka) among earlier representatives of H. sapiens or evolved gradually over the last 400 thousand years. Here we report newly discovered human fossils from Jebel Irhoud, Morocco, and interpret the affinities of the hominins from this site with other archaic and recent human groups. We identified a mosaic of features including facial, mandibular and dental morphology that aligns the Jebel Irhoud material with early or recent anatomically modern humans and more primitive neurocranial and endocranial morphology. In combination with an age of 315 ± 34 thousand years (as determined by thermoluminescence dating), this evidence makes Jebel Irhoud the oldest and richest African Middle Stone Age hominin site that documents early stages of the H. sapiens clade in which key features of modern morphology were established. Furthermore, it shows that the evolutionary processes behind the emergence of H. sapiens involved the whole African continent.
Anatomy of the Platysma Muscle Hwang, Kun; Kim, Ji Yeon; Lim, Jae Hyun
The Journal of craniofacial surgery,
03/2017, Letnik:
28, Številka:
2
Journal Article
Recenzirano
The aim of this paper was to review the anatomy the platysma systematically.The term "platysma AND anatomy" was used to search PubMed and Scopus, producing 394 and 214 papers, respectively. After ...excluding 95 duplicate titles, 513 abstracts and 98 full papers were reviewed. Among these 98 papers, 83 were excluded and 5 were added. Ultimately, 20 papers were analyzed.The most common aging-related change of the platysma was shortening (70.7%), followed by thinning (25.2%). The platysma most commonly originated from the upper portion of thorax anterior to clavicle (67.7%), followed by the subcutaneous tissue of the subclavicular and acromial regions (22.6%) and pectoralis (9.7%). The platysma ascended upward and medially (68.5%) or ascended from the clavicle to the face (31.5%). The platysma most commonly inserted on the cheek skin (57.5%), followed by the cutaneous muscles around the mouth (18.6%), the mandibulocutaneous ligament or zygoma (18.6%), and the parotid fascia or periosteum of the mandible (5.3%). The platysma was most commonly innervated by the cervical branch of the facial nerve (38.2%) or the cervical branch and mandibular branch of the facial nerve (60.5%), followed by the cervical plexus (0.6%), the cervical motor nucleus (0.6%), and the glossopharyngeal nerve (0.1%). The most common action of the platysma was drawing the lips inferiorly (83.3%) or posteriorly (12.9%). Four papers classified the platysma into subtypes; however, these classification strategies used arbitrary standards.Further studies will be necessary to establish the thickness of the platysma and to characterize age-related changes of the platysma.
The primary aim of this study was to evaluate the differences in labial plate thickness in patients identified as having thin versus thick/average periodontal biotypes. The association between ...biotype and labial plate thickness was evaluated by correlating information obtained from cone beam computed tomographs, diagnostic impressions, and clinical examinations of the maxillary anterior teeth (canine to canine) in 60 patients. Compared to a thick/average biotype, a thin biotype was associated with thinner labial plate thickness (P < .001), narrower keratinized tissue width (P < .001), greater distance from the cementoenamel junction to the initial alveolar crest (P = .02), and probe visibility through the sulcus. There was no relationship between biotype and tooth height-to-width ratio or facial recession. Periodontal biotype is significantly related to labial plate thickness, alveolar crest position, keratinized tissue width, gingival architecture, and probe visibility but unrelated to facial recession.
At present, no consensus has been reached on the compartmental subdivision of the jugular foramen (JF), which can complicate surgical planning in this area and hinder understanding of foraminal tumor ...growth patterns. The extradural neural axis compartment (EDNAC) might aid in producing a standardized model in the future. In the present review, we have summarized the models of JF compartmentalization and analyzed how sound they are anatomically.
The present narrative review identified the key studies and supporting reports that had discussed, referenced, or first presented models of JF compartmentalization.
Three intraforaminal components serve as the basis for JF compartmentalization: the fibro-osseous bridge, neurovascular contents, and EDNAC. A total of 4 models have been proposed to date. These include the 2-part (bipartite) models by Hovelacque (1934) and Shapiro (1972) and the 3-part (tripartite) subdivisions by Katsuta (1997) and Bernard (2018).
The bipartite model has been criticized as being oversimplified and lacking surgical validity. However, support for this compartmentation has persisted despite the increasing popularity of the tripartite model. The 3-part subdivision of Bernard can be considered the most anatomically faithful model to date owing to the consideration of the dura and EDNAC. It is important that future studies consider the entire anatomy of the JF, which may generate an anatomically accurate and surgically applicable compartmental model.
Discoveries of bird-like theropod dinosaurs and basal avialans in recent decades have helped to put the iconic 'Urvogel' Archaeopteryx into context and have yielded important new data on the origin ...and early evolution of feathers. However, the biological context under which pennaceous feathers evolved is still debated. Here we describe a new specimen of Archaeopteryx with extensive feather preservation, not only on the wings and tail, but also on the body and legs. The new specimen shows that the entire body was covered in pennaceous feathers, and that the hindlimbs had long, symmetrical feathers along the tibiotarsus but short feathers on the tarsometatarsus. Furthermore, the wing plumage demonstrates that several recent interpretations are problematic. An analysis of the phylogenetic distribution of pennaceous feathers on the tail, hindlimb and arms of advanced maniraptorans and basal avialans strongly indicates that these structures evolved in a functional context other than flight, most probably in relation to display, as suggested by some previous studies. Pennaceous feathers thus represented an exaptation and were later, in several lineages and following different patterns, recruited for aerodynamic functions. This indicates that the origin of flight in avialans was more complex than previously thought and might have involved several convergent achievements of aerial abilities.
By identifying homogeneity in bone and soft tissue covariation patterns in living hominids, it is possible to produce facial approximation methods with interspecies compatibility. These methods may ...be useful for producing facial approximations of fossil hominids that are more realistic than currently possible. In this study, we conducted an interspecific comparison of the nasomaxillary region in chimpanzees and modern humans with the aim of producing a method for predicting the positions of the nasal tips of Plio-Pleistocene hominids. We addressed this aim by first collecting and performing regression analyses of linear and angular measurements of nasal cavity length and inclination in modern humans (Homo sapiens; n = 72) and chimpanzees (Pan troglodytes; n = 19), and then performing a set of out-of-group tests. The first test was performed on four subjects that belonged to the same genus as the training sample, i.e., Homo (n = 2) and Pan (n = 2), and the second test, which functioned as an interspecies compatibility test, was performed on Pan paniscus (n = 1), Gorilla gorilla (n = 3), Pongo pygmaeus (n = 1), Pongo abelli (n = 1), Symphalangus syndactylus (n = 3), and Papio hamadryas (n = 3). We identified statistically significant correlations in both humans and chimpanzees with slopes that displayed homogeneity of covariation. Prediction formulae combining these data were found to be compatible with humans and chimpanzees as well as all other African great apes, i.e., bonobos and gorillas. The main conclusion that can be drawn from this study is that our set of regression models for approximating the position of the nasal tip are homogenous among humans and African apes, and can thus be reasonably extended to ancestors leading to these clades.
Anatomical studies in animals have described multiple striatal circuits and suggested that sub-components of the striatum, although functionally related, project to distinct cortical areas. To date, ...anatomical investigations in humans have been limited by methodological constraints such that most of our knowledge of fronto-striatal networks relies on nonhuman primate studies. To better identify the fronto-striatal pathways in the human brain, we used Diffusion Tensor Imaging (DTI) tractography to reconstruct neural connections between the frontal cortex and the caudate nucleus and putamen in vivo. We demonstrate that the human caudate nucleus is interconnected with the prefrontal cortex, inferior and middle temporal gyrus, frontal eye fields, cerebellum and thalamus; the putamen is interconnected with the prefrontal cortex, primary motor area, primary somatosensory cortex, supplementary motor area, premotor area, cerebellum and thalamus. A connectivity-based seed classification analysis identified connections between the dorsolateral prefrontal areas (DLPFC) and the dorsal-posterior caudate nucleus and between the ventrolateral prefrontal areas (VLPFC) and the ventral-anterior caudate nucleus. For the putamen, connections exist between the supplementary motor area (SMA) and dorsal-posterior putamen while the premotor area projects to medial putamen, and the primary motor area to the lateral putamen. Identifying the anatomical organization of the fronto-striatal network has important implications for understanding basal ganglia function and associated disease processes.
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