Haloe Antarctic observations in the spring of 1991

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95167/1/grl6630.pd

Mn Interstitial Diffusion in (Ga,Mn)As

We present a combined theoretical and experimental study of the ferromagnetic semiconductor (Ga,Mn)As which explains the remarkably large changes observed on low temperature annealing. Careful control of the annealing conditions allows us to obtain samples with ferromagnetic transition temperatures up to 159 K. Ab initio calculations, and resistivity measurements during annealing, show that the observed changes are due to out-diffusion of Mn interstitials towards the surface, governed by an energy barrier of about 0.7-0.8 eV. The Mn interstitial is a double donor resulting in compensation of charge carriers and suppression of ferromagnetism. Electric fields induced by high concentrations of substitutional Mn acceptors have a significant effect on the diffusion.Comment: 5 pages, 4 figures, submitted to Physical Review Letter

Development of bone marrow lesions is associated with adverse effects on knee cartilage while resolution is associated with improvement - a potential target for prevention of knee osteoarthritis: a longitudinal study

INTRODUCTION: To examine the relationship between development or resolution of bone marrow lesions (BMLs) and knee cartilage properties in a 2 year prospective study of asymptomatic middle-aged adults. METHODS: 271 adults recruited from the Melbourne Collaborative Cohort Study, underwent a magnetic resonance imaging scan (MRI) of their dominant knee at baseline and again approximately 2 years later. Cartilage volume, cartilage defects and BMLs were determined at both time points. RESULTS: Among 234 subjects free of BMLs at baseline, 33 developed BMLs over 2 years. The incidence of BMLs was associated with progression of tibiofemoral cartilage defects (OR 2.63 (95% CI 0.93, 7.44), P = 0.07 for medial compartment; OR 3.13 (95% CI 1.01, 9.68), P = 0.048 for lateral compartment). Among 37 subjects with BMLs at baseline, 17 resolved. Resolution of BMLs was associated with reduced annual loss of medial tibial cartilage volume (regression coefficient -35.9 (95%CI -65, -6.82), P = 0.02) and a trend for reduced progression of medial tibiofemoral cartilage defects (OR 0.2 (95% CI 0.04, 1.09), P = 0.06). CONCLUSIONS: In this cohort study of asymptomatic middle-aged adults the development of new BMLs was associated with progressive knee cartilage pathology while resolution of BMLs prevalent at baseline was associated with reduced progression of cartilage pathology. Further work examining the relationship between changes and BML and cartilage may provide another important target for the prevention of knee osteoarthritis

Conformal Mapping on Rough Boundaries II: Applications to bi-harmonic problems

We use a conformal mapping method introduced in a companion paper to study the properties of bi-harmonic fields in the vicinity of rough boundaries. We focus our analysis on two different situations where such bi-harmonic problems are encountered: a Stokes flow near a rough wall and the stress distribution on the rough interface of a material in uni-axial tension. We perform a complete numerical solution of these two-dimensional problems for any univalued rough surfaces. We present results for sinusoidal and self-affine surface whose slope can locally reach 2.5. Beyond the numerical solution we present perturbative solutions of these problems. We show in particular that at first order in roughness amplitude, the surface stress of a material in uni-axial tension can be directly obtained from the Hilbert transform of the local slope. In case of self-affine surfaces, we show that the stress distribution presents, for large stresses, a power law tail whose exponent continuously depends on the roughness amplitude

Psychoneuroimmunology-Based Stress Management during Adjuvant Chemotherapy for Early Breast Cancer

Objective. In a randomized trial of women with early stage breast cancer undergoing adjuvant chemotherapy, two stress management interventions, tai chi training and spiritual growth groups, were compared to a usual care control group, to evaluate psychosocial functioning, quality of life (QOL), and biological markers thought to reflect cancer- and treatment-specific mechanisms. Method. The sample consisted of 145 women aged 27–75 years; 75% were Caucasian and 25% African American. A total of 109 participants completed the study, yielding a 75% retention rate. Grounded in a psychoneuroimmunology framework, the overarching hypothesis was that both interventions would reduce perceived stress, enhance QOL and psychosocial functioning, normalize levels of stress-related neuroendocrine mediators, and attenuate immunosuppression. Results. While interesting patterns were seen across the sample and over time, the interventions had no appreciable effects when delivered during the period of chemotherapy. Conclusions. Findings highlight the complex nature of biobehavioral interventions in relation to treatment trajectories and potential outcomes. Psychosocial interventions like these may lack sufficient power to overcome the psychosocial or physiological stress experienced during the chemotherapy treatment period. It may be that interventions requiring less activity and/or group attendance would have enhanced therapeutic effects, and more active interventions need to be tested prior to and following recovery from chemotherapy

Distinct sex-specific gene expression changes in the placenta in association with childhood allergy

BACKGROUND: The prevalence of allergic disease has risen significantly during recent years. A major component of the susceptibility to allergic disease is determined in prenatal life, when the placenta plays a central role in fetal growth and development. In this study, we aimed to identify the patterns of gene expression in the placenta that may program early immune function to increase susceptibility to allergy. METHODS: A set of immune genes known to be associated with asthma, allergy and inflammation were selected for analysis by quantitative real-time polymerase chain reaction (qRT-PCR) on placental tissue from infants who did or did not develop an allergy by 2 years of age. Analysis was performed on males and females separately for each allergy type including eczema, rhinitis or asthma. RESULTS: Of 11 candidate allergy-associated genes tested by qRT-PCR, 4 were found to be associated with the development of specific childhood allergy types (P < 0.05). These included MMP9 for both males and females that developed eczema, TLR7 for females that developed eczema, KITL1 for males that developed rhinitis and ORMDL3 for females that developed asthma. CONCLUSIONS: This study has identified altered expression of placental genes involved in inflammation in association with the development of specific allergies in childhood. The current data provide supporting evidence implicating the placenta in programming the fetal immune system in early life.Astrud R Tuck, Luke E Grzeskowiak, Annette Osei-Kumah, Zarqa Saif, Suzanne M Edwards, Andrew Tai, Susan L Prescott, MeriTulic, Richard Saffery, and Vicki L Clifto

Voice, autonomy and utopian desire in participatory film-making with young refugees

This article is a reflection on what reflexive documentary scholars call the ‘moral dimension’ (Nash 2012: 318) of a participatory filmmaking project with refugee young people, who wanted to make a film to support other new young arrivals in the process of making home in Scotland. In the first part, we highlight some of the challenges of collaborating with refugee young people, in light of the often de-humanising representations of refugees in mainstream media and the danger of the triple conflation of authenticity-voice-pain in academic narratives about refugees. In the second part, we show how honouring young people’s desire to convey the hopeful aspects of making home, emerged as a key pedagogical strategy to affirm their expert position and encourage their participation in the project. Revisiting key moments of learning and interaction, we demonstrate how young people’s process of ‘finding a voice’ in moment-by-moment filmmaking practice was not a linear, developmental process towards ‘pure’ individual empowerment and singular artistic expression. Their participation in shaping their visual (self-)representation in the final film, was embedded in the dialogical process and pragmatic requirements of a collaborative film production, in which voice, autonomy and teacher authority were negotiated on a moment-by-moment basis. We conclude that it is vital for a reflexive practice and research to not gloss over the moral dilemmas in the name of progressive ideals, for example, when representations are co-created by project filmmakers/educators, but embrace these deliberations as part of the ‘fascinating collaborative matrix’ (Chambers 2019: 29) of participatory filmmaking

Dietary fatty acid intake affects the risk of developing bone marrow lesions in healthy middle-aged adults without clinical knee osteoarthritis: a prospective cohort study

INTRODUCTION: Fatty acids have been implicated in osteoarthritis (OA), yet the mechanism by which fatty acids affect knee structure and consequently the risk of knee OA has not been fully elucidated. Higher intakes of fatty acids have been shown to be associated with the risk of bone marrow lesions (BMLs) in a healthy population. The aim of this study was to examine the association between fatty acid consumption and the incidence of BMLs in healthy middle-aged adults without clinical knee OA. METHODS: Two hundred ninety-seven middle-aged adults without clinical knee OA underwent magnetic resonance imaging (MRI) of their dominant knee at baseline. BMLs were assessed. Of the 251 participants with no BMLs in their knee at baseline, 230 underwent MRI of the same knee approximately 2 years later. Intakes of fatty acids were estimated from a food frequency questionnaire. RESULTS: Increased consumption of saturated fatty acids was associated with an increased incidence of BMLs over 2 years after adjusting for energy intake, age, gender, and body mass index (odds ratio of 2.56 for each standard deviation increase in dietary intake, 95% confidence interval 1.03 to 6.37, P = 0.04). Intake of monounsaturated or polyunsaturated fatty acids was not significantly associated with the incidence of BMLs. CONCLUSIONS: Increased fatty acid consumption may increase the risk of developing BMLs. As subchondral bone is important in maintaining joint integrity and the development of OA, this study suggests that dietary modification of fatty acid intake may be one strategy in the prevention of knee OA which warrants further investigation

A Decolonial Critique of the Racialized “Localwashing” of Extraction in Central Africa

Responding to calls for increased attention to actions and reactions “from above” within the extractive industry, we offer a decolonial critique of the ways in which corporate entities and multinational institutions propagate racialized rhetoric of “local” suffering, “local” consultation, and “local” fault for failure in extractive zones. Such rhetoric functions to legitimize extractive intervention within a set of practices that we call localwashing. Drawing from a decade of research on and along the Chad-Cameroon Oil Pipeline, we show how multi-scalar actors converged to assert knowledge of, responsibility for, and collaborations with “local” people within a racialized politics of scale. These corporate representations of the racialized “local” are coded through long-standing colonial tropes. We identify three interrelated and overlapping flexian elite rhetoric(s) and practices of racialized localwashing: (a) anguishing, (b) arrogating, and (c) admonishing. These elite representations of a racialized “local” reveal diversionary efforts “from above” to manage public opinion, displace blame for project failures, and domesticate dissent in a context of persistent scrutiny and criticism from international and regional advocates and activists