410 research outputs found

    300 years of tropospheric ozone changes using CMIP6 scenarios with a parameterised approach

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    Tropospheric Ozone (O3) is both an air pollutant and a greenhouse gas. Predicting changes to O3 is therefore important for both air quality and near-term climate forcing. It is computationally expensive to predict changes in tropospheric O3 from every possible future scenario in composition climate models like those used in the 6th Coupled Model Intercomparison Project (CMIP6). Here we apply the different emission pathways used in CMIP6 with a model based on source-receptor relationships for tropospheric O3 to predict historical and future changes in O3 and its radiative forcing over a 300 year period (1750–2050). Changes in regional precursor emissions (nitrogen oxides, carbon monoxide and volatile organic compounds) and global methane abundance are used to quantify the impact on tropospheric O3 globally and across 16 regions, neglecting any impact from changes in climate. We predict large increases in global surface O3 (+8 ppbv) and O3 radiative forcing (+0.3 W m−2) over the industrial period. Nine different Shared Socio-economic Pathways are used to assess future changes in O3. Scenarios involving weak air pollutant controls and climate mitigation are inadequate in limiting the future degradation of surface O3 air quality and enhancement of near-term climate warming over all regions. Middle-of-the-road and strong mitigation scenarios reduce both surface O3 concentrations and O3 radiative forcing by up to 5 ppbv and 0.17 W m−2 globally, providing benefits to future air quality and near-term climate forcing. Sensitivity experiments show that targeting mitigation measures towards reducing global methane abundances could yield additional benefits for both surface O3 air quality and near-term climate forcing. The parameterisation provides a valuable tool for rapidly assessing a large range of future emission pathways that involve differing degrees of air pollutant and climate mitigation. The calculated range of possible responses in tropospheric O3 from these scenarios can be used to inform other modelling studies in CMIP6

    With my mouth

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    This collection of short stories explores many possible forms and uses of the genre of science fiction, ranging from explorations of the impact of science upon philosophical and religious issues and vice versa, to speculations about possible future understandings of identity rooted in ethnicity, culture, and even species. These stories range in setting and mood from a bizarre but humorous alternate history (á la Dickens) to a Buddhist-inhabited far-future dystopia, and employ a wide range of techniques and strategies. While these stories tend to use traditional (realist) narrative techniques, they use them strategically to immerse readers in performative examinations of many issues which are often addressed through formal experimentation--sometimes from perspectives that address these issues more forcefully than a formal experiment might succeed in doing. While thereby seeking to literally "hack" (in both senses of the word) readerly assumptions, these stories also argue performatively for a much wider range of imaginative possibilities and suitable topics of direct examination for SF than is often utilized by its practitioners or even acknowledged possible by its readers, both those of the street and those of the academy

    An evaluation of two decades of aerosol optical depth retrievals from MODIS over Australia

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    We present an evaluation of Aerosol Optical Depth (AOD) retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) over Australia covering the period 2001–2020. We focus on retrievals from the Deep Blue (DB) and Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithms, showing how these compare to one another in time and space. We further employ speciated AOD estimates from Copernicus Atmospheric Monitoring Service (CAMS) reanalyses to help diagnose aerosol types and hence sources. Considering Australia as a whole, monthly mean AODs show similar temporal behaviour, with a well-defined seasonal peak in the Austral summer. However, excepting periods of intense biomass burning activity, MAIAC values are systematically higher than their DB counterparts by, on average, 50%. Decomposing into seasonal maps, the patterns of behaviour show distinct differences, with DB showing a larger dynamic range in AOD, with markedly higher AODs (ΔAOD∼0.1) in northern and southeastern regions during Austral winter and summer. This is counter-balanced by typically smaller DB values across the Australian interior. Site level comparisons with all available level 2 AOD data from Australian Aerosol Robotic Network (AERONET) sites operational during the study period show that MAIAC tends to marginally outperform DB in terms of correlation (RMAIAC = 0.71, RDB = 0.65) and root-mean-square error (RMSEMAIAC = 0.065, RMSEDB = 0.072). To probe this behaviour further, we classify the sites according to the predominant surface type within a 25 km radius. This analysis shows that MAIAC’s advantage is retained across all surface types for R and all but one for RMSE. For this surface type (Bare, comprising just 1.2% of Australia) the performance of both algorithms is relatively poor, (RMAIAC = 0.403, RDB = 0.332)

    Access to languages other than English in Australian universities: an educational pipeline of privilege

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    © 2018, © 2018 HERDSA. This article explores factors contributing to unequal patterns of access to languages other than English (LOTE) in Australian universities. A critical analysis of qualitative and quantitative data generated through interviews, surveys and document analysis reveals that underrepresentation in LOTE courses in Australian universities is attributable to: (a) unequal access to LOTE learning areas at the school level; (b) low tertiary entrance scores that do not grant access to elite universities that offer broad LOTE course options; (c) differential prior international learning experiences that inform dispositions towards intercultural competence, including proficiency in LOTE; and (d) limited provision of LOTE courses in regional university campuses. We conclude that access to foreign language courses in Australian universities is not equitable, and in the context of globalisation opportunities, this poses a risk of reproducing social disadvantage alongside other structural factors such as socio-economic status and regional background

    Degradation of GSPT1 causes TP53-independent cell death in leukemia while sparing normal hematopoietic stem cells

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    Targeted protein degradation is a rapidly advancing and expanding therapeutic approach. Drugs that degrade GSPT1 via the CRL4CRBN ubiquitin ligase are a new class of cancer therapy in active clinical development with evidence of activity against acute myeloid leukemia in early-phase trials. However, other than activation of the integrated stress response, the downstream effects of GSPT1 degradation leading to cell death are largely undefined, and no murine models are available to study these agents. We identified the domains of GSPT1 essential for cell survival and show that GSPT1 degradation leads to impaired translation termination, activation of the integrated stress response pathway, and TP53-independent cell death. CRISPR/Cas9 screens implicated decreased translation initiation as protective following GSPT1 degradation, suggesting that cells with higher levels of translation are more susceptible to the effects of GSPT1 degradation. We defined 2 Crbn amino acids that prevent Gspt1 degradation in mice, generated a knockin mouse with alteration of these residues, and demonstrated the efficacy of GSPT1-degrading drugs in vivo with relative sparing of numbers and function of long-term hematopoietic stem cells. Our results provide a mechanistic basis for the use of GSPT1 degraders for the treatment of cancer, including TP53-mutant acute myeloid leukemia

    Immunophenotypic analysis of cell cycle status in acute myeloid leukaemia: relationship to cytogenetics, genotype and clinical outcome

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    Cell cycle status may play an important role in directing patient therapy. We therefore determined the cell cycle status of leukaemic cells by immunophenotypic analysis of bone marrow trephine biopsies from 181 patients with acute myeloid leukaemia (AML) and correlated the results with biological features and clinical outcome. There was considerable heterogeneity between patients. The presenting white cell count significantly correlated with the proportion of non-quiescent cells (P < 0·0001), of cycling cells beyond G1 (P < 0·0001) and the speed of cycling (P < 0·0001). Profiles in acute promyelocytic leukaemia (APL) differed from non-APL and were consistent with more differentiated cells with reduced proliferative potential, but no significant differences were observed between non-APL cytogenetic risk groups. NPM1 mutations but not FLT3 internal tandem duplication (FLT3ITD ) were significantly associated with a higher proportion of cells beyond G1 (P = 0·002) and faster speed of cycling (P = 0·003). Resistance to standard cytosine arabinoside and daunorubicin induction chemotherapy was significantly related to a slower speed of cycling (P = 0·0002), as was a higher relapse rate (P = 0·05), but not with the proportion of non-quiescent cells or actively cycling cells. These results show a link between the cycling speed of AML cells and the response to chemotherapy, and help to identify a group with a very poor prognosis

    Imaging Fourier transform spectrometers for environmental sensing

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77073/1/AIAA-1998-291-523.pd

    Ethnicity and the Writing of Medieval Scottish history

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    Historians have long tended to define medieval Scottish society in terms of interactions between ethnic groups. This approach was developed over the course of the long nineteenth century, a formative period for the study of medieval Scotland. At that time, many scholars based their analysis upon scientific principles, long since debunked, which held that medieval 'peoples' could only be understood in terms of 'full ethnic packages'. This approach was combined with a positivist historical narrative that defined Germanic Anglo-Saxons and Normans as the harbingers of advances of Civilisation. While the prejudices of that era have largely faded away, the modern discipline still relies all too often on a dualistic ethnic framework. This is particularly evident in a structure of periodisation that draws a clear line between the 'Celtic' eleventh century and the 'Norman' twelfth. Furthermore, dualistic oppositions based on ethnicity continue, particularly in discussions of the law, kingship, lordship and religion

    Lunar Flashlight: Illuminating the Lunar South Pole

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    Recent reflectance data from LRO instruments suggest water ice and other volatiles may be present on the surface in lunar permanentlyshadowed regions, though the detection is not yet definitive. Understanding the composition, quantity, distribution, and form of water and other volatiles associated with lunar permanently shadowed regions (PSRs) is identified as a NASA Strategic Knowledge Gap (SKG) for Human Exploration. These polar volatile deposits are also scientifically interesting, having the potential to reveal important information about the delivery of water to the Earth- Moon system

    Lunar Flashlight: Illuminating the Moon's South Pole

    Get PDF
    Recent reflectance data from LRO instruments suggest water ice and other volatiles may be present on the surface in lunar permanently shadowed regions, though the detection is not yet definitive. Understanding the composition, quantity, distribution, and form of water and other volatiles associated with lunar permanently shadowed regions (PSRs) is identified as a NASA Strategic Knowledge Gap (SKG) for Human Exploration. These polar volatile deposits are also scientifically interesting, having the potential to reveal important information about the delivery of water to the Earth-Moon system
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