63 research outputs found

    Assessment of CMIP6 performance and projected temperature and precipitation changes over South America

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    We evaluate the performance of a large ensemble of Global Climate Models (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) over South America for a recent past reference period and examine their projections of twenty-first century precipitation and temperature changes. The future changes are computed for two time slices (2040–2059 and 2080–2099) relative to the reference period (1995–2014) under four Shared Socioeconomic Pathways (SSPs, SSP1–2.6, SSP2–4.5, SSP3–7.0 and SSP5–8.5). The CMIP6 GCMs successfully capture the main climate characteristics across South America. However, they exhibit varying skill in the spatiotemporal distribution of precipitation and temperature at the sub-regional scale, particularly over high latitudes and altitudes. Future precipitation exhibits a decrease over the east of the northern Andes in tropical South America and the southern Andes in Chile and Amazonia, and an increase over southeastern South America and the northern Andes—a result generally consistent with earlier CMIP (3 and 5) projections. However, most of these changes remain within the range of variability of the reference period. In contrast, temperature increases are robust in terms of magnitude even under the SSP1–2.6. Future changes mostly progress monotonically from the weakest to the strongest forcing scenario, and from the mid-century to late-century projection period. There is an increase in the seasonality of the intra-annual precipitation distribution, as the wetter part of the year contributes relatively more to the annual total. Furthermore, an increasingly heavy-tailed precipitation distribution and a rightward shifted temperature distribution provide strong indications of a more intense hydrological cycle as greenhouse gas emissions increase. The relative distance of an individual GCM from the ensemble mean does not substantially vary across different scenarios. We found no clear systematic linkage between model spread about the mean in the reference period and the magnitude of simulated sub-regional climate change in the future period. Overall, these results could be useful for regional climate change impact assessments across South America

    An integrated environmental and fairtrade labelling scheme for product supply chains

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    Environmental initiatives such as carbon labelling have been suggested as a driver for achieving sustainable production systems of product supply chains. The paper therefore presents a systematic process of developing an environmental labelling framework as an extension of carbon labelling using the fairtrade certification as a platform to facilitate the process. Using the general theoretical constructs of lifecycle assessments, the framework presented provides insight into the formulation of multi-regional supply chains which has been specifically characterised in this paper for the UK-India-Rest of the World supply chain. The environmental labelling process presented in this paper is based on two key principles; Quantitative Principle in Eco-labelling and the Principle of Whole Lifecycle Perspective and it is used to inform two key stakeholder groups in the supply chain: consumers and supply chain partners. For consumers, a consistent way of presenting the environmental label information is presented highlighting the supply chain impacts across the indicators of CO2-eq emissions, water consumption and land use in addition to regional contributions to these impacts from a global supply chain perspective. Additionally, communicating the environmental impacts to supply chain partners provides a decision support to take actions to reduce the overall impacts by identifying processes within the global supply chain that needed prioritization. Given that fairtrade partnership is based on participatory development and a strict guidelines and standardization process, it is envisaged that synergies can be derived by integrating environmental labelling with the fairtrade scheme to enhance the environmental sustainability of product supply chains

    Machine Learning Identifies Stemness Features Associated with Oncogenic Dedifferentiation.

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    Cancer progression involves the gradual loss of a differentiated phenotype and acquisition of progenitor and stem-cell-like features. Here, we provide novel stemness indices for assessing the degree of oncogenic dedifferentiation. We used an innovative one-class logistic regression (OCLR) machine-learning algorithm to extract transcriptomic and epigenetic feature sets derived from non-transformed pluripotent stem cells and their differentiated progeny. Using OCLR, we were able to identify previously undiscovered biological mechanisms associated with the dedifferentiated oncogenic state. Analyses of the tumor microenvironment revealed unanticipated correlation of cancer stemness with immune checkpoint expression and infiltrating immune cells. We found that the dedifferentiated oncogenic phenotype was generally most prominent in metastatic tumors. Application of our stemness indices to single-cell data revealed patterns of intra-tumor molecular heterogeneity. Finally, the indices allowed for the identification of novel targets and possible targeted therapies aimed at tumor differentiation

    Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission

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    AbstractUnderstanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university. We identify considerable onward transmission associated with student accommodation and courses; this was effectively contained using local infection control measures and following a national lockdown. Transmission clusters were largely segregated within the university or the community. Our study highlights key determinants of SARS-CoV-2 transmission and effective interventions in a higher education setting that will inform public health policy during pandemics.</jats:p

    Molecular characterization and clinical relevance of metabolic expression subtypes in human cancers.

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    Metabolic reprogramming provides critical information for clinical oncology. Using molecular data of 9,125 patient samples from The Cancer Genome Atlas, we identified tumor subtypes in 33 cancer types based on mRNA expression patterns of seven major metabolic processes and assessed their clinical relevance. Our metabolic expression subtypes correlated extensively with clinical outcome: subtypes with upregulated carbohydrate, nucleotide, and vitamin/cofactor metabolism most consistently correlated with worse prognosis, whereas subtypes with upregulated lipid metabolism showed the opposite. Metabolic subtypes correlated with diverse somatic drivers but exhibited effects convergent on cancer hallmark pathways and were modulated by highly recurrent master regulators across cancer types. As a proof-of-concept example, we demonstrated that knockdown of SNAI1 or RUNX1—master regulators of carbohydrate metabolic subtypes-modulates metabolic activity and drug sensitivity. Our study provides a system-level view of metabolic heterogeneity within and across cancer types and identifies pathway cross-talk, suggesting related prognostic, therapeutic, and predictive utility

    Pancreatic and Colonic Abscess Formation Secondary to HELLP Syndrome

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    Preeclampsia and the variant HELLP syndrome are systemic conditions associated with vascular changes resulting in vasoconstriction. Most commonly, patients present with elevated blood pressure and proteinuria, with a background of complaints such as headache, scotoma, and right upper quadrant pain. The systemic vascular changes experienced can target any organ system, oftentimes with more than one organ system being involved. We present the case of a patient admitted with HELLP syndrome who subsequently developed multisystem organ dysfunction, including placental abruption, disseminated intravascular coagulopathy, acute renal failure, colitis, abdominal ascites, pancreatitis, and the development of pancreatic and colonic abscesses
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