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Stephen Cameron

Publications and source records attributed to Stephen Cameron.

4 recordsLinked to original sources
PubMed2006

A genomic perspective on the shortcomings of mitochondrial DNA for "barcoding" identification.

Approximately 600-bp sequences of mitochondrial DNA (mtDNA) have been designated as "DNA barcodes" and have become one of the most contentious and animated issues in the application of genetic information to global biodiversity assessment and species identification. Advocates of DNA barcodes have received extensive attention and promotion in many popular and refereed scientific publications. However, we suggest that the utility of barcodes is suspect and vulnerable to technical challenges that are particularly pertinent to mtDNA. We review the natural history of mtDNA and discuss problems for barcoding which are particularly associated with mtDNA and inheritance, including reduced effective population size, maternal inheritance, recombination, inconsistent mutation rate, heteroplasmy, and compounding evolutionary processes. The aforementioned could significantly limit the application and utility of mtDNA barcoding efforts. Furthermore, global use of barcodes will require application and acceptance of a barcode-based species concept that has not been evaluated in the context of the extensive literature concerning species designation. Implementation of mtDNA barcodes in spite of technical and practical shortcomings we discuss may degrade the longstanding synthesis of genetic and organism-based research and will not advance studies ranging from genomic evolution to biodiversity assessment.

Animals↗
PubMed2005

Are plant DNA barcodes a search for the Holy Grail?

In a recent study, Kress et al. compared two plant genomes to seek out plant DNA barcodes. Two promising markers balanced the variability that is needed to distinguish species with conserved primer regions that enable universal amplification. Although this study is the most rigorous effort to date, problems from earlier barcoding efforts, such as the use of non-evolutionary species concepts and differential sorting of genes and species, could reemerge. Single-gene barcoding might not be universally effective owing to inherent inaccuracies. Kress et al. suggest the use of multiple genes, reflecting an integrated approach that is likely to be the best answer to identifying species quickly and accurately.

Biodiversity↗
PubMed2005

Helicopter primary retrieval: tasking who should do it?

BACKGROUND: Cairns Base Hospital utilizes a helicopter retrieval system, which until 2001 had been tasked and staffed by emergency physicians. Since 2001, the ambulance service has assumed the role of both tasking and staffing the helicopter with intensive care paramedics. The present study examines whether the change has resulted in different activation patterns and patient outcomes. METHOD: A retrospective chart review over 4 consecutive years, comparing the two groups, was carried out examining 30 day mortality, length of in-hospital stay, transfer rates, the Revised Trauma Score where appropriate and rates of discharge directly from the ED. RESULTS: A total of 374 patients were retrieved (211 patients in the emergency physician group from 1 April 1999 to 31 March 2001 and 163 in the ambulance group from 1 April 2001 to 31 March 2003) over the 4 year period. The demographics of the two groups were similar. Fifty-four patients in the ambulance group (33.1%) were discharged from the ED without admission while 31 (14.7%) were discharged from the physician group. This was statistically significant (P = 0.0001). There were no other significant differences between the two groups. The subgroup of patients admitted also did not show any significant difference in outcomes. CONCLUSION: The similarities in outcomes for admitted patients support the view that both groups have similar tasking criteria for high-acuity patients and suggest that paramedics are as efficacious as physicians in delivering prehospital care in this group of patients. However, for lower-acuity patients, there is a statistically significant higher rate of clinically unnecessary taskings by the ambulance group. Given the recent fatal aeromedical accidents in Queensland (Thursday Island 1998, Rockhampton 1999 and Mackay 2003), it would seem prudent to reduce clinically unnecessary retrievals through clinical coordination with appropriately qualified emergency physicians.

Adult↗