My colleagues and myself are happy to invite you all to Join the Pod for
the second episode of the webinar series!
Join us on *Friday*, *10th December at 12* (noon - GMT/UTC) for Episode 02:
"*Cetaceans from above: drones for research*" (Episode 2: Cetaceans from
above - YouTube <https://www.youtube.com/watch?v=4W1GLJ3x1wU>). Three
amazing invited speakers, three different species, three different research
objectives. A great program lined up:
- *"Continuous focal group follows operated by a drone enable analysis of
the relation between sociality and position in a group of male Risso's
dolphins* (*Grampus griseus*)" - Dr. Karin Hartman, Nova Atlantis Foundation
- *"Scale of the whale: measuring sperm whales in northern Norway"* - Sean
O'Callaghan, Galway-Mayo Institute of Technology & Norwegian Sperm Whale
Research Project
- "*Blowing off steroids: collecting blow samples with drones to measure
stress-related hormones*" - Tom Grove, University of Edinburgh & WhaleWise
The talks will be followed by a live Q&A for you to ask all your questions.
So get ready for take off... You can subscribe to the webinars here:
jointhepodseminars.wixsite.com/jointhepod
<http://www.jointhepodseminars.wixsite.com/jointhepod> and on YouTube
https://www.youtube.com/channel/UC625JyiWKMvTSLwCjciM6Ig to stay tuned
about our upcoming monthly episodes!
Hope to have many of you with us,
Kind regards,
Fiona Cummins, Joanne O'Brien, María Pérez Tadeo, Morgane Pommier & Cynthia
Barile
Dear MARMAM subscribers,
My co-authors and I are pleased to announce the following paper in the
*Archives
of Oral Biology*:
*Microstructure, elemental composition and mechanical properties of enamel
and dentine in the polar bear Ursus maritimus*
Carolina Loch, Louisa Hemm, Bertie Taylor, Ingrid N. Visser, Øystein Wiig
https://doi.org/10.1016/j.archoralbio.2021.105318
*Abstract*
Objective: To investigate the microstructure, elemental composition and
mechanical properties of polar bear teeth.
Design: Incisors, canines and fourth premolar teeth of two subadult male
museum specimens were analysed. Teeth were measured, photographed, embedded
in Epoxy resin, sectioned, polished and etched for scanning electron
microscope (SEM) imaging, elemental composition and nanomechanical testing
analyses.
Results: The thickness of enamel ranged from 350 to 430µm in canines, 220
to 330µm in incisors and 320 to 510µm in premolars. SEM images showed
distinct transversely-oriented undulating Hunter Schreger bands (HSB) from
the enamel-dentine junction (EDJ) to the outer enamel surface. Enamel
prisms had a hexagonal shape, with open prism sheaths. Prisms measured
6-8µm in diameter. The EDJ was straight with no evidence of scalloping.
Larger tubules adjacent to the EDJ were observed in the mantle dentine
zone. Enamel Hardness and Elastic modulus values were higher in premolars
(6.9 GPa and 269 GPa), followed by canines (6.5 GPa and 230 GPa) and
incisors (4.9 GPa and 187 GPa). Dentine Hardness and Elastic modulus values
were higher in canines. CaO and P2O5 were the components with higher oxide
weight percentage in both enamel and dentine.
Conclusions: Understanding the microstructure, elemental composition and
mechanical properties of polar bear teeth can help elucidate the biology
and functional morphology of this globally threatened species and could be
used as a proxy for studies with fossil ursids.
Keywords: Elastic modulus; Hardness; Hunter-Schreger bands; Ursidae; Teeth
Full text is available at:
https://www.sciencedirect.com/science/article/pii/S0003996921002818
Or alternatively, a *pdf* can be requested at: carolina.loch(a)otago.ac.nz
Best regards,
_______________________________________
Carolina Loch Silva, PhD
Lecturer in Oral Biology
Department of Oral Sciences
Sir John Walsh Research Institute
Faculty of Dentistry, University of Otago
Dunedin 9054, New Zealand
Phone: +(64) 03 479-9255
http://www.otago.ac.nz/sjwri/people/profile/index.html?id=2033
