Changes in vertical ice extent along the East Antarctic Ice Sheet margin in western Dronning Maud Land – initial field and modelling results of the MAGIC-DML collaboration

Constraining numerical ice sheet models by comparison with observational data is crucial to address the interactions between cryosphere and climate at a wide range of scales. Such models are tested and refined by comparing model predictions of past ice geometries with field-based reconstructions from geological, geomorphological, and ice core data. However, for the East Antarctic Ice sheet, there is a critical gap in the empirical data necessary to reconstruct changes in ice sheet geometry in the Dronning Maud Land (DML) region. In addition, there is poor control on the regional climate history of the ice sheet margin, because ice-core locations, where detailed reconstructions of climate history exist, are located on high inland domes. This leaves numerical models ofregional glaciation history in this near-coastal area largely unconstrained. MAGIC-DML is an ongoing Swedish-US-Norwegian-German-UK collaboration with a focus on improvingice sheet models of the western DML margin by combining advances in modeling with filling critical data gaps regarding the timing and pattern of ice-surface changes. A combination of geomorphological mapping using remote sensing data, field observations, cosmogenic nuclide surface exposure dating, and numerical ice sheetmodeling are being used in an iterative manner to produce a comprehensive reconstruction of the glacial historyof western DML. Here, we present an overview of the project, field evidence for formerly higher ice surfaces and in-situ cosmogenic nuclide measurements from the 2016/17 expedition. Preliminary field evidence indicate that interior sectors of DML have experienced a general decrease in ice sheet thickness since the late Miocene, with potential episodes of increasing thickness in the late Pleistocene (700-300 ka, 250-75 ka). To aid in interpreting these field data, new high-resolution ice sheet model reconstructions, constraining ice sheet configurations during key episodes, are presented

Mid-Pleistocene ice sheet fluctuations from cosmogenic nuclide field constraints in western Dronning Maud Land, Antarctica

The East Antarctic Ice Sheet (EAIS) is generally assumed to have been relatively insensitive to Quaternary climat echange. However, recent studies have shown potential instabilities in coastal, marine sectors of the EAIS. In addition, long-term climate reconstructions and modelling experiments indicate the potential for significant changes in ice volume and ice sheet configuration since the Pliocene. Hence, more empirical evidence for ice surface and ice volume changes is required to discriminate between contrasting inferences. MAGIC-DML is an ongoing Swedish-US-Norwegian-German-UK collaboration focused on improving ice sheetm odels by filling critical data gaps that exist in our knowledge of the timing and pattern of ice surface changes along the western Dronning Maud Land (DML) margin and combining this with advances in numerical techniques. As part of the project, field studies in the 2016/17 and 2017/18 austral summers targeted selected sites spanning accessible altitudes in the Heimefrontfjella, Vestfjella, Ahlmannryggen, Borgmassivet, and Kirwanveggen nunatakranges for in situcosmogenic nuclide sampling. Comparing concentrations of nuclides with widely differing half-lives in bedrock and erratics from a range of altitudes above modern ice surfaces can provide information on ice sheet fluctuations and complex burial and exposure histories, and thus, past configurations of non-erosive ice. Quartz-bearing rock types were sampled and analyzed for 10Be (t1/21.4 My),14C (t1/25.7 ky),26Al (t1/2705ky), and 21Ne (stable), and mafic lithologies for36Cl (t1/2301 ky). Results thus far for 3210Be and 26Al isotope pairs complemented with seven21Ne measurements have yielded some consistent patterns of paleoglaciation for the western DML margin. Eight out of fourteen bedrock samples from high-elevation (1700-2238 m a.s.l.) ridges and summits return some of the oldest exposure ages in Antarctica and have consistent 10Be,26Al, and 21Ne minimum apparent exposure ages of 1.8-4.1 Ma. Initial results therefore indicate that parts of the ice sheet marginal to the Antarctic plateau, along the Heimefrontfjella range, generally have experienced a decrease in ice thickness since the late Miocene. Another six bedrock samples (1556-1732 ma.s.l.) fall in the 300-700 ka range, and they all show significant burial. At face value, perhaps this indicates aregional ice sheet surface above 1700 m a.s.l. for much of the Plio-early Pleistocene. All other samples analyzedto date are erratics from lower elevation and more coastal sites (10 from nunataks at 553-1400 m a.s.l., and 6 froma surface moraine at 1385 m a.s.l.), exhibiting ages between 59 and 275 ka, save for two (4 and 6 ka). Whereas almost all of the nunatak erratics (including the young ones) show significant burial durations, five of the six surface moraine samples do not. These 2016/17 field samples are not yet leading to conclusive age constraints but already start to paint a picture of the western DML margin being relatively stable although there was possibly one or more episodes of relatively limited ice thickening during the last 700 ka

Creative destruction in science

Drawing on the concept of a gale of creative destruction in a capitalistic economy, we argue that initiatives to assess the robustness of findings in the organizational literature should aim to simultaneously test competing ideas operating in the same theoretical space. In other words, replication efforts should seek not just to support or question the original findings, but also to replace them with revised, stronger theories with greater explanatory power. Achieving this will typically require adding new measures, conditions, and subject populations to research designs, in order to carry out conceptual tests of multiple theories in addition to directly replicating the original findings. To illustrate the value of the creative destruction approach for theory pruning in organizational scholarship, we describe recent replication initiatives re-examining culture and work morality, working parents\u2019 reasoning about day care options, and gender discrimination in hiring decisions. Significance statement It is becoming increasingly clear that many, if not most, published research findings across scientific fields are not readily replicable when the same method is repeated. Although extremely valuable, failed replications risk leaving a theoretical void\u2014 reducing confidence the original theoretical prediction is true, but not replacing it with positive evidence in favor of an alternative theory. We introduce the creative destruction approach to replication, which combines theory pruning methods from the field of management with emerging best practices from the open science movement, with the aim of making replications as generative as possible. In effect, we advocate for a Replication 2.0 movement in which the goal shifts from checking on the reliability of past findings to actively engaging in competitive theory testing and theory building. Scientific transparency statement The materials, code, and data for this article are posted publicly on the Open Science Framework, with links provided in the article

Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

Relationship between molecular pathogen detection and clinical disease in febrile children across Europe: a multicentre, prospective observational study

BackgroundThe PERFORM study aimed to understand causes of febrile childhood illness by comparing molecular pathogen detection with current clinical practice.MethodsFebrile children and controls were recruited on presentation to hospital in 9 European countries 2016-2020. Each child was assigned a standardized diagnostic category based on retrospective review of local clinical and microbiological data. Subsequently, centralised molecular tests (CMTs) for 19 respiratory and 27 blood pathogens were performed.FindingsOf 4611 febrile children, 643 (14%) were classified as definite bacterial infection (DB), 491 (11%) as definite viral infection (DV), and 3477 (75%) had uncertain aetiology. 1061 controls without infection were recruited. CMTs detected blood bacteria more frequently in DB than DV cases for N. meningitidis (OR: 3.37, 95% CI: 1.92-5.99), S. pneumoniae (OR: 3.89, 95% CI: 2.07-7.59), Group A streptococcus (OR 2.73, 95% CI 1.13-6.09) and E. coli (OR 2.7, 95% CI 1.02-6.71). Respiratory viruses were more common in febrile children than controls, but only influenza A (OR 0.24, 95% CI 0.11-0.46), influenza B (OR 0.12, 95% CI 0.02-0.37) and RSV (OR 0.16, 95% CI: 0.06-0.36) were less common in DB than DV cases. Of 16 blood viruses, enterovirus (OR 0.43, 95% CI 0.23-0.72) and EBV (OR 0.71, 95% CI 0.56-0.90) were detected less often in DB than DV cases. Combined local diagnostics and CMTs respectively detected blood viruses and respiratory viruses in 360 (56%) and 161 (25%) of DB cases, and virus detection ruled-out bacterial infection poorly, with predictive values of 0.64 and 0.68 respectively.InterpretationMost febrile children cannot be conclusively defined as having bacterial or viral infection when molecular tests supplement conventional approaches. Viruses are detected in most patients with bacterial infections, and the clinical value of individual pathogen detection in determining treatment is low. New approaches are needed to help determine which febrile children require antibiotics.FundingEU Horizon 2020 grant 668303

Reconstructing Ice Sheet Surface Changes in Western Dronning Maud Land, Antarctica

Understanding climate-driven changes in global land-based ice volume is a critical component in our capability to predict how global sea level will rise as a consequence of the current humandriven climate change. At the last glacial maximum (LGM, which peaked around 20 ka), ephemeral ice sheets covered vast regions of the northern hemisphere while both the Greenland and Antarctic ice sheets were more extensive than at present. As global temperatures rose at the transition into the Holocene, driving the LGM deglaciation, eustatic sea level rose by approximately 125 m. The east Antarctic ice sheet (EAIS) is the largest ice sheet on Earth today, holding an ice volume equivalent to ca. 53 m rise in global sea level. Considering current trends in global climate, specifically rapidly increasing atmospheric CO2 levels and global temperature, it is important to improve our understanding of how the EAIS will respond to global warming so that we can make better predictions of future sea level changes to guide community adaptation and planning efforts. Numerical ice sheet models which inform projections of future ice volume changes, and can, therefore, yield projections of sea level rise, rely on empirical data to test their ability to accurately represent former and present ice configurations. However, there is a general lack of data on the paleoglaciology of the EAIS along the western Dronning Maud Land (DML) margin. In order to address this situation, the paleoglaciology of western DML forms the focus of the work presented in this thesis. Together with collaborators within the MAGIC-DML consortium (Mapping, Measuring and Modelling Antarctic Geomorphology and Ice Change in Dronning Maud Land) that provides the funding for this MS project, the author has performed geomorphological mapping across western DML; an area of approximately 200,000 km2 . The results of the mapping presented in this thesis will provide the basis for a detailed glacial reconstruction of the region. The geomorphological mapping was completed almost entirely by remote sensing using very high-resolution (sub-meter in the panchromatic) WordView-2 and WorldView-3 (WV) satellite imagery, combined with ground validation studies during field work. Compared to Landsat products, the improved spatial resolution provided by WV imagery has fundamentally changed the scale and detail at which remote sensing based geomorphological mapping can be completed. The mapping presented here is focused on the glacial geomorphology of mountain summits and flanks that protrude through the ice sheet’s surface (nunataks). In our study area of western DML these nunatak surfaces make up \u3c0.2 % of the total surface area, and the landforms mapped here are generally smaller than can be identified from Landsat products (30 m spatial resolution). The detail achieved in our mapping, across such a vast, remote area that presents numerous obstacles to accessibility highlights the benefits of utilizing the new VHR WV data. As such an evaluation of the WV data, as applied to geomorphological mapping is presented here together with our mapping of the glacial geomorphology of western DML. The results of which provides evidence of ice having overridden sites at all elevations across the entire study area; from the highest elevation inland nunataks that form the coast-parallel escarpment, to low-elevation emerging nunataks close to the coast. Hence from our studies of the glacial geomorphology of this region we can ascertain that, at some point in the glacial history of western DML, ice covered all of the mountain summits that are exposed today, indicating an ice sheet surface lowering of up to 700 m in some places

Assessing child and adolescent internalizing disorders

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Conversations in Times of Isolation: Exploring Rural-Dwelling Older Adults’ Experiences of Isolation and Loneliness during the COVID-19 Pandemic in Manitoba, Canada

Older adults have been described as a vulnerable group in the current context of the COVID-19 pandemic. In Canada, where this study took place, older adults have been encouraged to self-isolate while the rest of the population has been cautioned against in-person contact with them. Prior to COVID-19, social isolation and loneliness among older adults was considered a serious public health concern. Using a series of semi-structured interviews with 26 community-dwelling older adults (65+) living in rural Manitoba, we explore older adults’ experiences of isolation and loneliness in the initial stages of the pandemic between the months of May and July 2020. Participants identified a loss of autonomy, loss of activities and social spaces (e.g., having coffee or eating out, volunteering, and going to church), and lack of meaningful connection at home as factors influencing their sense of isolation and loneliness. Although these loses initially influenced participants’ self-reported isolation and loneliness, the majority developed strategies to mitigate isolation and loneliness, such as drawing on past experiences of isolation, engaging in physically distanced visits, connecting remotely, and “keeping busy.” Our findings call attention to the role of different environments and resources in supporting older adults social and emotional wellbeing, particularly as they adapt to changes in social contact over time

The Impact of brief parental anxiety management on child anxiety treatment outcomes : a controlled trial

Parental anxiety is a risk to optimal treatment outcomes for childhood anxiety disorders. The current trial examined whether the addition of a brief parental anxiety management (BPAM) program to family cognitive behavioral therapy (CBT) was more efficacious than family CBT-only in treating childhood anxiety disorders. Two hundred nine children (aged 6-13 years, 104 female, 90% Caucasian) with a principal anxiety disorder were randomly allocated to family CBT with a five-session program of BPAM (n = 109) or family CBT-only (n = 100). Family CBT comprised the Cool Kids program, a structured 12-week program that included both mothers and fathers. Overall, results revealed that the addition of BPAM did not significantly improve outcomes for the child or the parent compared to the CBT-only group at posttreatment or 6-month follow-up. Overall, however, children with nonanxious parents were more likely to be diagnosis free for any anxiety disorder compared to children with anxious parents at posttreatment and 6-month follow-up. BPAM did not produce greater reductions in parental anxiety. The results support previous findings that parent anxiety confers poorer treatment outcomes for childhood anxiety disorders. Nevertheless the addition of BPAM anxiety management for parents in its current format did not lead to additional improvements when used as an adjunct to family CBT in the treatment of the child's anxiety disorder. Future benefits may come from more powerful methods of reducing parents' anxiety.11 page(s

A topographic hinge-zone divides coastal and inland ice dynamic regimes in East Antarctica

The impact of late Cenozoic climate on the East Antarctic Ice Sheet is uncertain. Poorly constrained patterns of relative ice thinning and thickening impair the reconstruction of past ice-sheet dynamics and global sea-level budgets. Here we quantify long-term ice cover of mountains protruding the ice-sheet surface in western Dronning Maud Land, using cosmogenic Chlorine-36, Aluminium-26, Beryllium-10, and Neon-21 from bedrock in an inverse modeling approach. We find that near-coastal sites experienced ice burial up to 75–97% of time since 1 Ma, while interior sites only experienced brief periods of ice burial, generally <20% of time since 1 Ma. Based on these results, we suggest that the escarpment in Dronning Maud Land acts as a hinge-zone, where ice-dynamic changes driven by grounding-line migration are attenuated inland from the coastal portions of the East Antarctic Ice Sheet, and where precipitation-controlled ice-thickness variations on the polar plateau taper off towards the coast