2,672 research outputs found
Alien Registration- Carr, Thomas D. (Auburn, Androscoggin County)
https://digitalmaine.com/alien_docs/30920/thumbnail.jp
THE OSTEOLOGY OF ALIORAMUS, A GRACILE AND LONG-SNOUTED TYRANNOSAURID (DINOSAURIA: THEROPODA) FROM THE LATE CRETACEOUS OF MONGOLIA
Fig. 68: Closeup of right ilium of the holotype specimen of Alioramus altai (IGM 100/1844) in lateral view. Scale bar 5 5 cm. Abbreviations as in figure 66.Published as part of Brusatte, Stephen L., Carr, Thomas D. & Norell, Mark A., 2012, The Osteology Of Alioramus, A Gracile And Long-Snouted Tyrannosaurid (Dinosauria: Theropoda) From The Late Cretaceous Of Mongolia, pp. 1-197 in Bulletin of the American Museum of Natural History 2012 (366) on page 149, DOI: 10.1206/770.1, http://zenodo.org/record/539926
Keratoacanthoma management: results of a survey of UK dermatologists and surgeons.
Distinction of keratoacanthoma (KA) from squamous cell carcinoma (SCC) is challenging. Management is controversial, with some advocating prompt surgical excision and others monitoring to allow for spontaneous resolution(1) . The controversy is compounded by rare reports of metastasis(2) . And yet the benign natural history of KA is supported by various studies, including a systematic review of 455 cases with no cases of metastasis or death(1) , and observational studies confirming spontaneous resolution(1)
Crystallization and preliminary X-ray diffraction analysis of two N-terminal fragments of the DNA-cleavage domain of topoisomerase IV from Staphylococcus aureus. Corrigendum
A corrigendum to the paper by Carr et al. (2006), Acta Cryst. F62, 1164–1167
Crystallization and preliminary X-ray diffraction analysis of two N-terminal fragments of the DNA-cleavage domain of topoisomerase IV from Staphylococcus aureus
The crystallization and data collection of topoisomerase IV from S. aureus is described. Phasing by molecular replacement proved difficult owing to the presence of translational NCS and strategies used to overcome this are discussed
A new tyrannosaur with evidence for anagenesis and crocodile-like facial sensory system
A new species of tyrannosaurid from the upper Two Medicine Formation of Montana supports the presence of a Laramidian anagenetic (ancestor-descendant) lineage of Late Cretaceous tyrannosaurids. In concert with other anagenetic lineages of dinosaurs from the same time and place, this suggests that anagenesis could have been a widespread mechanism generating species diversity amongst dinosaurs, and perhaps beyond. We studied the excellent fossil record of the tyrannosaurid to test that hypothesis. Phylogenetic analysis places this new taxon as the sister species to Daspletosaurus torosus. However, given their close phylogenetic relationship, geographic proximity, and temporal succession, where D. torosus (~76.7–75.2 Ma) precedes the younger new species (~75.1–74.4 Ma), we argue that the two forms most likely represent a single anagenetic lineage. Daspletosaurus was an important apex predator in the late Campanian dinosaur faunas of Laramidia; its absence from later units indicates it was extinct before Tyrannosaurus rex dispersed into Laramidia from Asia. In addition to its evolutionary implications, the texture of the facial bones of the new taxon, and other derived tyrannosauroids, indicates a scaly integument with high tactile sensitivity. Most significantly, the lower jaw shows evidence for neurovasculature that is also seen in birds
Preserving the palaeoenvironmental record in Drylands: Bioturbation and its significance for luminescence-derived chronologies
Luminescence (OSL) dating has revolutionised the understanding of Late Pleistocene dryland activity. However,
one of the key assumptions for this sort of palaeoenvironmental work is that sedimentary sequences have been
preserved intact, enabling their use as proxy indicators of past changes. This relies on stabilisation or burial
soon after deposition and a mechanism to prevent any subsequent re-mobilisation. As well as a dating
technique OSL, especially at the single grain level, can be used to gain an insight into post-depositional
processes that may distort or invalidate the palaeoenvironmental record of geological sediment sequences.
This paper explores the possible impact of bioturbation (the movement of sediment by flora and fauna) on
luminescence derived chronologies from Quaternary sedimentary deposits in Texas and Florida (USA) which
have both independent radiocarbon chronologies and archaeological evidence. These sites clearly illustrate the
ability of bioturbation to rejuvenate ancient weathered sandy bedrock and/or to alter depositional stratigraphies
through the processes of exhumation and sub-surface mixing of sediment. The use of multiple OSL replicate
measurements is advocated as a strategy for checking for bioturbated sediment. Where significant OSL
heterogeneity is found, caution should be taken with the derived OSL ages and further measurements at the
single grain level are recommended. Observations from the linear dunes of the Kalahari show them to have no
bedding structure and to have OSL heterogeneity similar to that shown from the bioturbated Texan and Florida
sites. The Kalahari linear dunes could have therefore undergone hitherto undetected post-depositional sediment
disturbance which would have implications for the established OSL chronology for the region
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