703 research outputs found
The mitochondrial T1095C mutation increases gentamicin-mediated apoptosis
No full textAbstract not availableHakan Muyderman, Neil R. Sims, Masashi Tanaka, Noriyuki Fuku, Ravinarayan Raghupathi, Dominic Thyagaraja
Mechanisms of brain cell death in stroke
No full textDr Neil R Sims$AUD 144,352.66NHMRC Project GrantsStandard Project Gran
Brain cell death following Cardiac arrest
No full textDr Neil R Sims$AUD 278,379.59NHMRC Project GrantsStandard Project Gran
Mechanisms of selective brain cell death after cardiac arrest and stroke
No full textDr Neil R Sims$AUD 74,597.80NHMRC Project GrantsStandard Project Gran
Losses of NG2 and NeuN immunoreactivity but not astrocytic markers during early reperfusion following severe focal cerebral ischemia
No full textDiane R. Lee, Stephen C. Helps, Ian L. Gibbins, Michael Nilsson, Neil R. Sim
Synthesis of furanosesquiterpenoid natural products
No full textThe effect of addition of a catalytic quantity of a crown ether in the reaction of a phosphonate anion with a carbonyl compound (Wadsworth-Emmons reaction) has been studied and found to greatly facilitate this reaction. This modification of the Wadsworth-Emmons reaction, using a catalytic amount of 15-crown-5, has been employed in the synthesis of the naturally occurring furanosesquiterpene Pallescensin-E. The structure of this compound has been confirmed by comparison of its spectral data with that of the synthesised isomer, 4,l0-dihydro-7,8-dimethyl 10H-benzof4,5Jcycloheptafl,2-bJ furan.Homosesquirosefuran, an analogue of the naturally occurring furanosesquiterpene Sesquirosefuran, has been synthesised via the dianion of methylacetoacetate.An approach to the synthesis of Pinguisone (a component of the essential oil of the liverwort Aneura pinguis)has been attempted employing two Diels-Alder reactions to generate the four cis-methyl groups found in the natural product.In a study of the reaction of n-(2-methylallyl)nickel bromide complex with a range of epoxides, this complex was found not only to react with reactive epoxides (e.g. styrene epoxide) but also with less reactive propylene epoxide.Substrates for possible intramolecular n-allylnickel cyclisation to generate an a-methylene-6-valerolactone ring system have been prepared
"The Hangout was Serious Business:" Exploring Literacies and Learning in an Online Sims Fan Fiction Community
No full textabstract: The purpose of this study is to explore the literacy practices members of an online fan community engage in to participate in the space and to question what learning happens through that participation. This dissertation is the product of a two-year virtual ethnographic study of The Sims Writers' Hangout (SWH), a discussion forum website established by fans of The Sims to support members' interests in creating and sharing Sims fan fiction. Affinity space theory informs an understanding of SWH's organization, and a definition of literacies as situated, social practices also frames the study. Data were collected following a discourse-centered online ethnographic approach, which guided systematic observation and interactions with eight key informants. The data corpus includes hundreds of pages of discussion forum posts, member profiles, moderator-created norming texts, numerous digital, multimodal Sims fan fiction texts, virtual interview responses from informants, field notes, and additional virtual artifacts, such as informants' websites and Flickr® photostreams. Study results are presented within three separate manuscripts prepared for publication and presentation, each exploring different lines of inquiry related to SWH. Chapter 3 focuses on tensions visible in the forum discussions to argue for an expansion of affinity space theory that accounts for the “hanging out” members do in the space. Chapter 4 analyzes one informant's literacy practices using a Design perspective. This analysis reveals the collaborative nature of Sims fan fiction literacies. The final manuscript (Chapter 5) offers an analysis of SWH pedagogy using Bernstein's pedagogic device concept. Data illustrate how pedagogic discourse in this online, informal learning space aligns with and challenges Bernstein's theory. Finally, Chapter 6 offers conclusions about how these three analyses expand our understanding of adolescent literacies and 21st century learning. This chapter also contains implications for theory and practice, recommendations for future research, and reflections on lessons learned.Dissertation/ThesisPh.D. Curriculum and Instruction 201
Accuracy and reproducibility of coral Sr/Ca SIMS timeseries in modern and fossil corals
No full text© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Sayani, H., Cobb, K., Monteleone, B., & Bridges, H. Accuracy and reproducibility of coral Sr/Ca SIMS timeseries in modern and fossil corals. Geochemistry, Geophysics, Geosystems, 23(9), (2022): e2021GC010068, https://doi.org/10.1029/2021gc010068.Coral strontium-to-calcium ratios (Sr/Ca) provide quantitative estimates of past sea surface temperatures (SST) that allow for the reconstruction of changes in the mean state and climate variations, such as the El Nino-Southern Oscillation, through time. However, coral Sr/Ca ratios are highly susceptible to diagenesis, which can impart artifacts of 1–2°C that are typically on par with the tropical climate signals of interest. Microscale sampling via Secondary Ion Mass Spectrometry (SIMS) for the sampling of primary skeletal material in altered fossil corals, providing much-needed checks on fossil coral Sr/Ca-based paleotemperature estimates. In this study, we employ a set modern and fossil corals from Palmyra Atoll, in the central tropical Pacific, to quantify the accuracy and reproducibility of SIMS Sr/Ca analyses relative to bulk Sr/Ca analyses. In three overlapping modern coral samples, we reproduce bulk Sr/Ca estimates within ±0.3% (1σ). We demonstrate high fidelity between 3-month smoothed SIMS coral Sr/Ca timeseries and SST (R = −0.5 to −0.8; p < 0.5). For lightly-altered sections of a young fossil coral from the early-20th century, SIMS Sr/Ca timeseries reproduce bulk Sr/Ca timeseries, in line with our results from modern corals. Across a moderately-altered section of the same fossil coral, where diagenesis yields bulk Sr/Ca estimates that are 0.6 mmol too high (roughly equivalent to −6°C artifacts in SST), SIMS Sr/Ca timeseries track instrumental SST timeseries. We conclude that 3–4 SIMS analyses per month of coral growth can provide a much-needed quantitative check on the accuracy of fossil coral Sr/Ca-derived estimates of paleotemperature, even in moderately altered samples.We'd also like to thank Yolande Berta and Georgia Tech's Center for Nanostructure Characterization for providing access to their SEM facilities, and the Khaled bin Sultan Living Ocean Foundation and The Nature Conservancy for financial and logistical support for field excursions to Palmyra. Funding for this work was provided by the National Science Foundation (Award Numbers 1502832 and 2002458 to K.M.C) and the National Oceanic and Atmospheric Administration (Award Number: NA11OAR4310165 to K.M.C)
Historical data reveal power-law dispersal patterns of invasive aquatic species
No full textUnderstanding how invasive species spread is of particular concern in the current era of globalisation and rapid environmental change. The occurrence of super-diffusive movements within the context of Lévy flights has been discussed with respect to particle physics, human movements, microzooplankton, disease spread in global epidemiology and animal foraging behaviour. Super-diffusive movements provide a theoretical explanation for the rapid spread of organisms and disease, but their applicability to empirical data on the historic spread of organisms has rarely been tested. This study focuses on the role of long-distance dispersal in the invasion dynamics of aquatic invasive species across three contrasting areas and spatial scales: open ocean (north-east Atlantic), enclosed sea (Mediterranean) and an island environment (Ireland). Study species included five freshwater plant species, Azolla filiculoides, Elodea canadensis, Lagarosiphon major, Elodea nuttallii and Lemna minuta; and ten species of marine algae, Asparagopsis armata, Antithamnionella elegans, Antithamnionella ternifolia, Codium fragile, Colpomenia peregrina, Caulerpa taxifolia, Dasysiphonia sp., Sargassum muticum, Undaria pinnatifida and Womersleyella setacea. A simulation model is constructed to show the validity of using historical data to reconstruct dispersal kernels. Lévy movement patterns similar to those previously observed in humans and wild animals are evident in the re-constructed dispersal pattern of invasive aquatic species. Such patterns may be widespread among invasive species and could be exacerbated by further development of trade networks, human travel and environmental change. These findings have implications for our ability to predict and manage future invasions, and improve our understanding of the potential for spread of organisms including infectious diseases, plant pests and genetically modified organisms
The application of scanning electron microscopy to the determination of elemental and isotopic composition in individual actinide particles
No full textTechniques for the determination of both elemental and isotopic composition of actinides within single particles are required by the IAEA in support of their environmental safeguards programme. SEM and SIMS are valuable techniques for the measurement of elemental and isotopic composition, respectively, on the particle scale. The potential for effective combination of SEM and SIMS has been investigated at Harwell Laboratory. In trials, copper finder grids have been successfully used to enable re-identification of particles between SEM and SIMS instruments. Use of the grids enables rapid relocation of particles pre-selected by SEM for SIMS measurement. The work has highlighted a possible matrix effect in plutonium measurement that results in variable sensitivity dependent on the presence of other elements (including uranium). This effect would limit the use of SIMS to obtain elemental ratios, and highlights the requirement to use both SEM and SIMS to gain full and accurate information. The possible use of autoradiography as an adjunct to SEM has been investigated. In principle, autoradiography could be used to identify higher enrichments of uranium and enable pre-selection of particles for SIMS measurement. During trials, practical problems have been encountered which have demonstrated this particular approach to be unsuitable. (author)Also issued as AEAT/R/NS/0108 and UK A01036Available from British Library Document Supply Centre-DSC:9082.66732(277) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
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