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"Of which I took possession" : settler materiality & the Plains feathered headdress
No full textThe “war bonnet,” an eagle feathered headdress originating with the tribes of the North American Plains, has been a key element in material-based mimesis and commodification among non-Native people. Manufacturing headdress replicas has become a successful commercial project via major costume companies as well as small businesses, domestically and abroad. As a source of material fascination for non-Native people, this research traces the complex milieu of identity and object through an examination of the historic and contemporary interaction between the headdress and U.S. settlers. Written as a series of historical vignettes woven with ethnographic data this dissertation spans a period of 400 years, framing the consumption of the headdress within a reading of settler semiotics and a detailed chronology of U.S. iconography.
This project places special emphasis on how objects function in settler colonial contexts as a means of national identity, seeking to integrate settler colonial theory into research on objects and materiality. As such, I propose a new theoretical framework introducing the concepts of settler materiality and settler semiotics. This dissertation is multi-sited drawing on archival and ethnographic research in over twenty U.S. states and three countries
Elevated δ15N linked to inhibited nitrification coupled to ammonia volatilization in sediments of shallow alkaline-hypersaline lakes
Get PDFFunding: This work was supported by the NASA Fellowship Activity in support of C.J.T. under Cooperative Agreement no. 80NSSC19K1739 issued through the NASA Office of STEM Engagement. Funding was provided to T.W.L. through the NASA Astrobiology Institute under Cooperative Agreement No. NNA15BB03A issued through the Science Mission Directorate and the NASA Interdisciplinary Consortia for Astrobiology Research (ICAR). E.E.S. acknowledges funding from a NERC Frontiers grant (NE/V010824/1).Alkaline lakes are among the most bioproductive aquatic ecosystems on Earth. The factors that ultimately limit productivity in these systems can vary, but nitrogen (N) cycling in particular has been shown to be adversely affected by high salinity, evidently due to the inhibition of nitrifying bacteria (i.e., those that convert ammonic species to nitrogen oxides). The coastal plain of Coorong National Park in South Australia, which hosts several alkaline lakes along 130 km of coastline, provides an ideal natural laboratory for examining how fine-scale differences in the geochemistry of such environments can lead to broad variations in nitrogen cycling through time, as manifest in sedimentary δ15N. Moreover, the lakes provide a gradient of aqueous conditions that allows us to assess the effects of pH, salinity, and carbonate chemistry on the sedimentary record. We report a wide range of δ15N values (3.8‰–18.6‰) measured in the sediments (0–35 cm depth) of five lakes of the Coorong region. Additional data include major element abundances, carbonate δ13C and δ18O values, and the results of principal component analyses. Stable nitrogen isotopes and wt% sodium (Na) display positive correlation (R2 = 0.59, p < 0.001) across all lake systems. Principal component analyses further support the notion that salinity has historically impacted nitrogen cycling. We propose that the inhibition of nitrification at elevated salinity may lead to the accumulation of ammonic species, which, when exposed to the water column, are prone to ammonia volatilization facilitated by intervals of elevated pH. This process is accompanied by a significant isotope fractionation effect, isotopically enriching the nitrogen that remains in the lake water. This nitrogen is eventually buried in the sediments, preserving a record of these combined processes. Analogous enrichments in the rock record may provide important constraints on past chemical conditions and their associated microbial ecologies. Specifically, ancient terrestrial aquatic systems with high δ15N values attributed to denitrification and thus oxygen deficiency may warrant re-evaluation within the framework of this alternative. Constraints on pH as provided by elevated δ15N via ammonia volatilization may also inform critical aspects of closed-basin paleoenvironments and their suitability for a de novo origin of life.Peer reviewe
Parenteral nutrition emulsion inhibits CYP3A4 in an iPSC derived liver organoids testing platform
Get PDFFunding: Research Council of Norway. Grant Number: 262613. FRIPRO. Grant Number: 247624. UiO:Life Science. Grant Number: 20493.Objectives: Parenteral nutrition (PN) is used for patients of varying ages with intestinal failure to supplement calories. Premature newborns with low birth weight are at a high risk for developing PN associated liver disease (PNALD) including steatosis, cholestasis, and gallbladder sludge/stones. To optimize nutrition regimens, models are required to predict PNALD. Methods: We have exploited induced pluripotent stem cell derived liver organoids to provide a testing platform for PNALD. Liver organoids mimic the developing liver and contain the different hepatic cell types. The organoids have an early postnatal maturity making them a suitable model for premature newborns. To mimic PN treatment we used medium supplemented with either clinoleic (80% olive oil/20% soybean oil) or intralipid (100% soybean oil) for 7 days. Results: Homogenous HNF4a staining was found in all organoids and PN treatments caused accumulation of lipids in hepatocytes. Organoids exhibited a dose dependent decrease in CYP3A4 activity and expression of hepatocyte functional genes. The lipid emulsions did not affect overall organoid viability and glucose levels had no contributory effect to the observed results. Conclusions: Liver organoids could be utilized as a potential screening platform for the development of new, less hepatotoxic PN solutions. Both lipid treatments caused hepatic lipid accumulation, a significant decrease in CYP3A4 activity and a decrease in the RNA levels of both CYP3A4 and CYP1A2 in a dose dependent manner. The presence of high glucose had no additive effect, while Clinoleic at high dose, caused significant upregulation of interleukin 6 and TLR4 expression.Peer reviewe
Sexual selection, genomic evolution and population fitness in Drosophila pseudoobscura
Get PDFFunding: Natural Environment Research Council (grant number NE/V001566/1).Sexual selection shapes the genome in unique ways. It is also likely to have significant fitness consequences, such as purging deleterious mutations from the genome or conversely maintaining genetic load in a population via sexual conflict. Here, we examined what the influence of sexual selection has on genomic variation potentially underlying population fitness using experimentally evolved Drosophila pseudoobscura populations. Sexual selection was manipulated by keeping replicate lines in elevated polyandry or strict monogamy for approximately 200 generations followed by individual-based sequencing. Using pi (π), fixation index (Fst)and recombination rate measures, we confirmed signatures of selection were not dispersed but mainly localized to the third and X chromosome. Overall mutational load was similar between lines but our analysis of the distribution of fitness effects revealed considerable variation between lines and chromosomes. Furthermore, we found that the distribution of transposable elements differs between the lines, with a higher load in monogamous lines. Our results suggest that complex interactions between purifying selection and sexual conflict are shaping the genome, particularly on chromosome 3 and the sex chromosome; sexual selection influences divergence across chromosomes but in a more complex way than proposed by simple ‘purging’ of deleterious loci.Peer reviewe
Hiding in plain sight : children with visual perceptual difficulties in schools
Get PDFCerebral visual impairment (CVI) is increasingly being recognized as a significant cause of visual difficulties in children, particularly those with typical visual acuity, who nonetheless struggle in educational settings. This narrative review aims to elucidate the nature and impact of visual perceptual difficulties (VPD) associated with CVI in school-aged children, who often remain undiagnosed due to the current erroneous focus on visual acuity as a required diagnostic criterion for CVI. The review synthesizes findings from recent studies, highlighting that up to 3.4% of children in mainstream schools and a higher percentage in special educational settings may experience VPD, which significantly impacts upon their learning and development. The manifestations of VPDs, such as difficulties in motion perception, recognition, and visuospatial processing, are often subtle and can thus be overlooked, leading to misconceptions about the origins of the affected child’s abilities and behaviors. The review also discusses the challenges in current diagnostic processes, emphasizing the need for comprehensive history taking and assessments that go beyond standard visual acuity tests. It proposes a multi-faceted approach to identification and support, incorporating both clinical assessments and teacher/parental observations, to better address the needs of affected children. Furthermore, this paper advocates for the inclusion of VPDs in the International Classification of Diseases (ICD 11) to ensure children with these visual issues receive appropriate educational support. By integrating lived experiences of individuals with CVI and the latest research findings, this review underscores the urgent need for awareness and tailored educational strategies designed to support children with VPDs. The findings suggest that without such recognition and intervention, many children with VPDs will continue to “hide in plain sight,” facing unnecessary challenges in their educational and social development. The review concludes with recommendations for policy changes and future research directions to improve the identification, classification, and support of children with VPDs within the educational system.Peer reviewe
Theology and policing
Get PDFThis article assesses the notion of “policing” in John Perry and Joanna Leidenhag’s Science-Engaged Theology to consider the contemporary practice of theological inquiry as a theoretical endeavor. Drawing on their construal of science-engaged theology, which involves a twofold resistance towards “authoritarian” tendencies of asserting theology as the queen of the sciences as well as modernity’s “border police” who seek to exclude religion and theology from public discourse, this essay suggests that Perry and Leidenhag’s vision for science-engaged theology not only brings to light one of the ways theology is sometimes deployed as a political mechanism for policing but also how theology itself can perhaps even be considered an act of “theological de-policing.”Peer reviewe
Context-dependent coordination of movement in Tribolium castaneum larvae
Get PDFFunding: Institute for Behavioural and Neural Sciences, University of St Andrews - Undergraduate Research Assistant Scheme.Insect pests, like the red flour beetle Tribolium castaneum, destroy up to 20% of stored grain products worldwide, making them a significant threat to food security. Their success hinges upon adapting their movements to unpredictable, heterogeneous environments like flour. Tribolium is well developed as a genetic model system; however, little is known about their natural locomotion and how their nervous systems coordinate adaptive movement. Here, we employed videographic whole-animal and leg tracking to assess how Tribolium larvae locomote over different substrates and analyze their gait kinematics across speeds. Unlike many hexapods, larvae employed a bilaterally symmetric, posterior-to-anterior wave gait during fast locomotion. At slower speeds, coordination within thoracic segments was disrupted, although intersegmental coordination remained intact. Moreover, larvae used terminal abdominal structures (pygopods) to support challenging movements, such as climbing overhangs. Pygopod placement coincided with leg swing initiation, suggesting a stabilizing role as adaptive anchoring devices. Surgically lesioning the connective between thoracic and abdominal ganglia impaired pygopod engagement and led to escalating impairments in flat-terrain locomotion, climbing and tunnelling. These results suggest that effective movement in Tribolium larvae requires thoracic-abdominal coordination, and that larval gait and limb recruitment is context-dependent. Our work provides the first kinematic analysis of Tribolium larval locomotion and gives insights into its neural control, creating a foundation for future motor control research in a genetically tractable beetle that jeopardizes global food security.Peer reviewe
Longitudinal analysis within one hospital in sub-Saharan Africa over 20 years reveals repeated replacements of dominant clones of Klebsiella pneumoniae and stresses the importance to include temporal patterns for vaccine design considerations
Get PDFFunding: We acknowledge funding from Wellcome (EH; grant 217303/Z/19/Z) and the BMGF (NAF and EH; grant INV-005180) as well as Wellcome funding providing core support for the Wellcome Sanger Institute (206194) and MLW (206454).Background: Infections caused by multidrug-resistant gram-negative bacteria present a severe threat to global public health. The WHO defines drug-resistant Klebsiella pneumoniae as a priority pathogen for which alternative treatments are needed given the limited treatment options and the rapid acquisition of novel resistance mechanisms by this species. Longitudinal descriptions of genomic epidemiology of Klebsiella pneumoniae can inform management strategies but data from sub-Saharan Africa are lacking. Methods: We present a longitudinal analysis of all invasive K. pneumoniae isolates from a single hospital in Blantyre, Malawi, southern Africa, from 1998 to 2020, combining clinical data with genome sequence analysis of the isolates. Results: We show that after a dramatic increase in the number of infections from 2016 K. pneumoniae becomes hyperendemic, driven by an increase in neonatal infections. Genomic data show repeated waves of clonal expansion of different, often ward-restricted, lineages, suggestive of hospital-associated transmission. We describe temporal trends in resistance and surface antigens, of relevance for vaccine development. Conclusions: Our data highlight a clear need for new interventions to prevent rather than treat K. pneumoniae infections in our setting. Whilst one option may be a vaccine, the majority of cases could be avoided by an increased focus on and investment in infection prevention and control measures, which would reduce all healthcare-associated infections and not just one.Peer reviewe
Applying movement ecology models to comparative cognition experiments : a field test in hummingbirds
Get PDFFunding: D.J.P. was supported by the University of St Andrews, University of Lincoln and Newcastle University during the course of this study, while T.P. was funded by a Royal Society Newton International Fellowship (NF170682) between 2018 and 2020.Traditionally, evidence for spatial learning in animals involves experiments; however, tools developed for analysing tracking data are increasingly being used to infer the use of spatial memory and other cognitive processes in animal movements. In this study, we combined these statistical models with field experiments to analyse how patterns of hummingbird movements change as birds learn a rewarded location. Using hidden Markov models (HMMs), we used both changes in two movement states as well as experimental behavioural measures of spatial memory to determine how searching performance and behaviour changed as birds gained experience and how important local landmarks were for guiding search. Regardless of whether birds had a single training trial to learn a flower's location or 12 repeated trials, hummingbirds learned the location of the flower although performance suffered when we removed the local landmarks. While the hovering locations suggested that removing landmarks led to a slight decrease in accuracy compared with when landmarks were present, the HMMs suggest that this was part of a larger shift from a memory-led search strategy to a more systematic searching process. Our results suggests that models used in movement ecology could provide a valuable tool for experiments in comparative cognition.Peer reviewe
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