I had gone to teach but stayed to learn: Geraldine MacKenzie at Aurukun Mission, 1925-1965

This article examines the missionary career of Geraldine MacKenzie who, with her husband Bill MacKenzie, served on the Presbyterian mission at Aurukun on the Cape York Peninsula between 1925 and 1965. It focuses primarily on MacKenzie’s own interpretation of and reflection on her experiences, as described in her memoir, Aurukun Diary. While the memoir elides some of the more controversial features of the MacKenzies’ tenure at Aurukun, it provides insights into the changing nature of missionary theology and practice on Aboriginal missions in the early twentieth century, particularly as they relate to the role of women—both missionaries and mission residents.

Indigenous blood and ethical regimes in the United States and Australia since the 1960s

Blood samples collected from members of indigenous communities in the mid-20th century by scientists interested in human variation remain frozen today in institutional repositories around the world. This article focuses on two such collections-one established and maintained in the United States and the other in Australia. Through historical and ethnographic analysis, we show how scientific knowledge about the human species and ethical knowledge about human experimentation are coproduced differently in each national context over time. Through a series of vignettes, we trace the attempts of scientists and indigenous people to assemble and reassemble blood samples, ethical regimes, human biological knowledge, and personhood. In including ourselves-a U.S. historian of science and an Australian anthropologist-in the narrative, we show how humanistic and social scientific analysis contributes to ongoing efforts to maintain indigenous samples. [indigenous, biospecimens, science, genomics, postcolonial, ethics, cryopreservation].

Mountain barriers and river conduits: phylogeographical structure in a large, mobile lizard (Varanidae: Varanus varius) from eastern Australia

Aim: Across eastern Australia, mountain ranges (the Great Dividing Range) and river catchments (the Murray-Darling Basin) are likely to have shaped the phylogeographical structure of many species. We address how such processes have influenced the phylogeography of the lace monitor, Varanus varius, a large mobile lizard. Location: Eastern and south-eastern Australia. Methods: Phylogeographical hypotheses were tested using up to 90 museum and field-collected samples from across the entire species' range; a 671-bp region of the mtDNA gene ND4 was sequenced and all individuals were genotyped (eight microsatellite loci). Results: Maximum-likelihood analysis of sequence data revealed three geographically separate clades, with divergences estimated to have occurred during the Pleistocene. The south-eastern clade showed an expansion pattern from northern refugia and dispersal appears to have occurred along the Murray-Darling river system. Microsatellite analyses support mtDNA clades but indicate secondary contact in the Hunter Valley, New South Wales. Main conclusions: Our results indicate that phylogeographical structure and contemporary gene flow in Varanus varius is shaped by dispersal capacity, geographical barriers and the presence of ancient river corridors. Indeed, only the most significant geological (McPherson Range) and habitat barriers (Burdekin Gap) appear to limit gene flow in this species. The expansion of the clade on the western side of the Great Dividing Range suggests that ancient riparian corridors have facilitated extensive gene flow. Our study highlights the importance of understanding a species' ecological dynamics when examining broad-scale evolutionary patterns.

Fusing data mining, machine learning and traditional statistics to detect biomarkers associated with depression

BACKGROUND: Atheoretical large-scale data mining techniques using machine learning algorithms have promise in the analysis of large epidemiological datasets. This study illustrates the use of a hybrid methodology for variable selection that took account of missing data and complex survey design to identify key biomarkers associated with depression from a large epidemiological study.

METHODS: The study used a three-step methodology amalgamating multiple imputation, a machine learning boosted regression algorithm and logistic regression, to identify key biomarkers associated with depression in the National Health and Nutrition Examination Study (2009-2010). Depression was measured using the Patient Health Questionnaire-9 and 67 biomarkers were analysed. Covariates in this study included gender, age, race, smoking, food security, Poverty Income Ratio, Body Mass Index, physical activity, alcohol use, medical conditions and medications. The final imputed weighted multiple logistic regression model included possible confounders and moderators.

RESULTS: After the creation of 20 imputation data sets from multiple chained regression sequences, machine learning boosted regression initially identified 21 biomarkers associated with depression. Using traditional logistic regression methods, including controlling for possible confounders and moderators, a final set of three biomarkers were selected. The final three biomarkers from the novel hybrid variable selection methodology were red cell distribution width (OR 1.15; 95% CI 1.01, 1.30), serum glucose (OR 1.01; 95% CI 1.00, 1.01) and total bilirubin (OR 0.12; 95% CI 0.05, 0.28). Significant interactions were found between total bilirubin with Mexican American/Hispanic group (p = 0.016), and current smokers (p<0.001).

CONCLUSION: The systematic use of a hybrid methodology for variable selection, fusing data mining techniques using a machine learning algorithm with traditional statistical modelling, accounted for missing data and complex survey sampling methodology and was demonstrated to be a useful tool for detecting three biomarkers associated with depression for future hypothesis generation: red cell distribution width, serum glucose and total bilirubin.