Search

Your search keyword '"Austin, Jeremy"' showing total 1,075 results
Start Over Author "Austin, Jeremy"
1,075 results on '"Austin, Jeremy"'

3. Integrating spectrophotometric and XRD analyses in the investigation of burned dental remains

Author

Rahmat, Rabiah A., Humphries, Melissa A., Austin, Jeremy J., Linacre, Adrian M. T., Raven, Mark, and Self, Peter

Subjects
Condensed Matter - Materials Science, Physics - Medical Physics, Statistics - Applications
Abstract

Heat alters colour and crystallinity of teeth by destruction of the organic content and inducing hydroxyapatite crystal growth. The colour and crystallite changes can be quantified using spectrophotometric and x-ray diffraction analyses, however these analyses are not commonly used in combination to evaluate burned dental remains. In this study, thirty-nine teeth were incinerated at 300-1000$^\circ$C for 15 and 30 minutes and then measured using a spectrophotometer and an x-ray diffractometer. Response variables used were lightness, L$^\ast$, and chromaticity a$^\ast$ and b$^\ast$ and luminance (whiteness and yellowness) for colour, and crystal size for crystallinity. Statistical analysis to determine the attribution of these variables revealed yellowness and crystal size were significantly affected by temperature ($p < 0.05$), whilst duration of heat-exposure showed no significant effect. This study suggests the inclusion of both spectrophotometric and x-ray diffraction in investigating thermal-heated teeth is useful to accurately estimate the temperature teeth are exposed to.

Published
2020
Full Text
View/download PDF

19. 52,000 years of woolly rhinoceros population dynamics reveal extinction mechanisms.

Author

Fordham, Damien A., Brown, Stuart C., Canteri, Elisabetta, Austin, Jeremy J., Lomolino, Mark V., Haythorne, Sean, Armstrong, Edward, Bocherens, Hervé, Manica, Andrea, Rey-Iglesia, Alba, Rahbek, Carsten, Nogués-Bravo, David, and Lorenzen, Eline D.

Subjects
POPULATION dynamics, RHINOCEROSES, HOLOCENE extinction, FOSSIL DNA, GLACIAL Epoch
Abstract

The extinction of the woolly rhinoceros (Coelodonta antiquitatis) at the onset of the Holocene remains an enigma, with conflicting evidence regarding its cause and spatiotemporal dynamics. This partly reflects challenges in determining demographic responses of late Quaternary megafauna to climatic and anthropogenic causal drivers with available genetic and paleontological techniques. Here, we show that elucidating mechanisms of ancient extinctions can benefit from a detailed understanding of fine-scale metapopulation dynamics, operating over many millennia. Using an abundant fossil record, ancient DNA, and high-resolution simulation models, we untangle the ecological mechanisms and causal drivers that are likely to have been integral in the decline and later extinction of the woolly rhinoceros. Our 52,000-y reconstruction of distribution-wide metapopulation dynamics supports a pathway to extinction that began long before the Holocene, when the combination of cooling temperatures and low but sustained hunting by humans trapped woolly rhinoceroses in suboptimal habitats along the southern edge of their range. Modeling indicates that this ecological trap intensified after the end of the last ice age, preventing colonization of newly formed suitable habitats, weakening stabilizing metapopulation processes, triggering the extinction of the woolly rhinoceros in the early Holocene. Our findings suggest that fragmentation and resultant metapopulation dynamics should be explicitly considered in explanations of late Quaternary megafauna extinctions, sending a clarion call to the fragility of the remaining large-bodied grazers restricted to disjunct fragments of poor-quality habitat due to anthropogenic environmental change. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

36. Developing Loop Mediated Isothermal Amplification (LAMP) assays for rapid, presumptive DNA detection of an invasive reptile (Boa constrictor).

Author

Deliveyne, Nathan, Austin, Jeremy J., and Cassey, Phillip

Abstract

Context. Wildlife trade is a prominent pathway for invasive species introductions into novel environments. Deliberate or accidental release of exotic pets can result in the establishment of alien populations, with damaging impacts for native species and environmental assets. This process is well documented for reptiles globally and is of considerable biosecurity concern in Australia. Boa constrictor is one species at high risk of establishment in Australia, and has insufficient biosecurity detection and post-border control capacity. Aims. We aimed to develop rapid DNA-based presumptive testing capacity for detecting B. constrictor, with appropriate sensitivity and specificity to operate in a trace DNA biosecurity context. Methods. Loop Mediated Isothermal Amplification (LAMP) is an emerging biosecurity tool that provides highly specific, sensitive, low-resource methods for detection of trace DNA in the absence of physical evidence. We developed colourimetric and fluorescent LAMP assays targeting the mitochondrial DNA control region of B. constrictor. We tested and validated these assays against synthetic DNA fragments, as well as DNA extracted from: (1) vouchered museum B. constrictor tissue; (2) shed B. constrictor skin samples; (3) a range of non-target species to test specificity; and (4) trace DNA recovered from glass tanks post B. constrictor presence. Key results. We successfully detected synthetic target DNA down to 1 fg and genomic B. constrictor DNA from tissue and shed skins down to <10 pg in under 30 minutes with our fluorescence-based LAMP assay. Additionally, we were able to detect B. constrictor trace DNA following 24 h of presence utilising a traditional laboratory-based DNA extraction method (approximately 180 min) and a rapid lysis step (approximately 8 min). Conclusions. Both colourimetric and fluorescent assays show promise for the specific detection of B.constrictor in biosecurity contexts, including post-border enforcement and compliance checksin the domestic illicit wildlife trade. Implications. Our findings greatly strengthen the ongoing development of biosecurity tools for trace DNA detection of commonly traded and trafficked species (i.e. reptiles) in wildlife enforcement contexts, advancing both preparedness and surveillance. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

45. Shining a LAMP on the applications of isothermal amplification for monitoring environmental biosecurity

Author

Deliveyne, Nathan, Young, Jennifer, Austin, Jeremy J., and Cassey, Phill

Subjects
wildlife forensics, loop mediated isothermal amplification (LAMP), Environmental biosecurity, invasive species
Abstract

Environmental biosecurity risks associated with the transnational wildlife trade include the loss of biodiversity, threats to public health, and the proliferation of invasive alien species. To assist enforcement agencies in identifying species either intentionally (trafficked) or unintentionally (stowaway) entrained in the trade-chain pathway, rapid forensic techniques are needed to enable their detection from DNA samples when physical identification is not possible. Loop Mediated Isothermal Amplification (LAMP) is an emerging technique, with recent applications in biosecurity and forensic sciences, which has potential to function as a field-based detection tool. Here we provide an overview of current research that applies LAMP to environmental biosecurity, including identification of ornamental wildlife parts, consumer products, and invasive species monitoring and biosecurity detection. We discuss the current scope of LAMP as applied to various wildlife trade scenarios and biosecurity checkpoint monitoring, highlight the specificity, sensitivity, and robustness for these applications, and review the potential utility of LAMP for rapid field-based detection at biosecurity checkpoints. Based on our assessment of the literature we recommend broader interest, research uptake, and investment in LAMP as an appropriate field-based species detection method for a wide range of environmental biosecurity scenarios.

Published
2023

Catalog

Books, media, physical & digital resources
See catalog results