Anatomy models using Silicone Moulds - An innovative meth

Introduction: Neuroanatomy specimens like cerebrum, cerebellum, brain stem, etc. when taken out of preservation solution dries up and becomes discoloured within a short span of time. These specimens are easily damaged when used repeatedly and become unfit for teaching. The models of these specimen made with silicone using silicone moulds are similar to the original specimens with excellent surface detailing.Using silicone moulds, models like vertebrae using resin also can be made. Materials and methods : The silicone material used in our study is Moldsil P. For making a silicone mould, an acrylic jar is made, which is little bigger than the specimen. Moldsil P is mixed with hardner and poured into the container so that it fills half the volume of the jar. The specimen is immersed into the silicone in such a way that only its upper half is exposed. After the silicone is hardened, the rest of the specimen is covered with the silicone mixture [Moldsil P+hardener] and allowed to dry. The specimen is taken out and the cavity of the impression is filled with silicone or resin to make a cast. Results & Conclusion: The silicone models of neuroanatomy specimens made using silicone moulds are soft, easy to handle and are exactly similar to the specimens. These are used as an alternative teaching aid. Silicone moulds can be used for taking resin cast of vertebra

Paleoneuroanatomy of the aetosaur Neoaetosauroides engaeus (Archosauria: Pseudosuchia) and its paleobiological implications among archosauriforms

The paleoneuroanatomy of pseudosuchian archosaurs is poorly known, based on direct examination of the internal morphology of braincases and a few artificial endocasts. Among aetosaurs, only one endocast has been described almost a century ago by Case (1921) corresponding to Desmatosuchus spurensis from the Chinle Formation (Norian) of Texas, US, based on a resin cast. Here, we describe the first natural endocast of an aetosaur, Neoaetosauroides engaeus from the Los Colorados Formation (Norian) of NW Argentina, and also developed the first digital endocast of this taxon including the encephalon, cranial nerves, inner ear, and middle ear sinuses. The neuroanatomy of Neoaetosauroides engaeus exhibits several differences from that of Desmatosuchus spurensis despite their phylogenetic proximity, which may be a reflection of their different habits. The information provided by the endocasts of Neoaetosauroides engaeus about its olfactory region and the orientation of its head, based on the inclination of the inner ear, could support the proposal for an animalivorous diet, instead of an herbivorous one as in most aetosaurs. The new information here obtained contributes to the knowledge of the neuroanatomical diversity of archosauriforms and more specifically among pseudosuchians and their paleobiological roles in the Triassic continental communities.

Mudslide and/or animal attack are more plausible causes and circumstances of death for AL 288 (‘Lucy'): A forensic anthropology analysis

Following a global morphological and micro-CT scan examination of the original and cast of the skeleton of Australopithecus afarensis AL 288 (‘Lucy’), Kappelman et al. have recently proposed a diagnosis of a fall from a significant height (a tree) as a cause of her death. According to topographical data from the discovery site, complete re-examination of a high-quality resin cast of the whole skeleton and forensic experience, we propose that the physical process of a vertical deceleration cannot be the only cause for her observed injuries. Two different factors were involved: rolling and multiple impacts in the context of a mudslide and an animal attack with bite marks, multi-focal fractures and violent movement of the body. It is important to consider a differential diagnosis of the observed fossil lesions because environmental factors should not be excluded in this ancient archaeological context as with any modern forensic anthropological case.

Imaging Resin-Cast Osteocyte Lacuno-Canalicular System at Bone-Bioactive Glass Interface by Scanning Electron Microscopy

The morphology of the osteocyte lacuno-canalicular system at the bone-biomaterial implant-interface has not been fully investigated. In this study, the resin-cast scanning electron microscopy technique was used, for the first time, to image the lacuno-canalicular network within neoformed bone around bioactive glass (BG) particles implanted in rat tibia bone marrow. The most salient finding was that the osteocyte canaliculi pass through the calcium-phosphorus layer formed at the bone-BG interface and reach the silica-rich layer of the reacted BG.

Diffusion Pathways for Heartwood Substances in Acacia Mangium

The cellular distribution of heartwood substances and the structure of the pathways for their diffusion were studied in Acacia mangium Willd. Apart from ray parenchyma cells, axial parenchyma cells also are involved in the formation of heartwood substances. Heartwood substances were unevenly distributed in the heartwood. A closer inspection of interfibre pit pairs revealed that, although many pit membranes were completely covered with encrusting materials, some pit pairs had many small openings on their pit membranes. The openings possibly function as intercellular diffusion pathways for heartwood substances. The sizes of the pits varied considerably, ranging from 0.4 to 2.3 μm in diameter. These structural variations in the interfiber pits might be one of the factors contributing to the uneven distribution of the heartwood substances. A large number of blind pits were present in the ray parenchyma cells and faced the intercellular spaces, into which heartwood substances from the ray parenchyma cells were released via these blind pits. Resin-cast replicas demonstrated that the intercellular spaces and the blind pits formed a three-dimensional network that is considered to serve as an extracellular diffusion pathway for heartwood substances.