1,481 research outputs found

    Coupled ocean-atmosphere modeling and predictions

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    Key aspects of the current state of the ability of global and regional climate models to represent dynamical processes and precipitation variations are summarized. Interannual, decadal, and globalwarming timescales, wherein the influence of the oceans is relevant and the potential for predictability is highest, are emphasized. Oceanic influences on climate occur throughout the ocean and extend over land to affect many types of climate variations, including monsoons, the El Niño Southern Oscillation, decadal oscillations, and the response to greenhouse gas emissions. The fundamental ideas of coupling between the ocean-atmosphere-land system are explained for these modes in both global and regional contexts. Global coupled climate models are needed to represent and understand the complicated processes involved and allow us to make predictions over land and sea. Regional coupled climate models are needed to enhance our interpretation of the fine-scale response. The mechanisms by which large-scale, low-frequency variations can influence shorter timescale variations and drive regionalscale effects are also discussed. In this light of these processes, the prospects for practical climate predictability are also presented.AJMwas supported by theNSFEarth System Modeling Program (OCE1419306) and the NOAA Climate Variability and Prediction Program (NA14OAR4310276). HS thanks the Office of Naval Research for support under N00014-15-1-2588. LPP was supported by “Advanced Studies in Medium and High Latitudes Oceanography” (CAPES 23038.004304/2014-28) and “National Institute of Science andTechnology of the Cryosphere” (CNPq/PROANTAR704222/2009). VM was supported by NOAA grant NA12OAR4310078. TGJ was supported by the U. S. Naval Research Laboratory 6.2 project “Fresh Water Balance in the Coupled Ocean-Atmosphere System” (BE-435-040-62435N-6777) YHT was supported by the MOST grant 106-2111-M-002-001, Taiwan

    Hepatitis B Virus X Protein Drives Multiple Cross-Talk Cascade Loops Involving NF-ÎșB, 5-LOX, OPN and Capn4 to Promote Cell Migration

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    Hepatitis B virus X protein (HBx) plays an important role in the development of hepatocellular carcinoma (HCC). However, the mechanism remains unclear. Recently, we have reported that HBx promotes hepatoma cell migration through the upregulation of calpain small subunit 1 (Capn4). In addition, several reports have revealed that osteopontin (OPN) plays important roles in tumor cell migration. In this study, we investigated the signaling pathways involving the promotion of cell migration mediated by HBx. We report that HBx stimulates several factors in a network manner to promote hepatoma cell migration. We showed that HBx was able to upregulate the expression of osteopontin (OPN) through 5-lipoxygenase (5-LOX) in HepG2-X/H7402-X (stable HBx-transfected cells) cells. Furthermore, we identified that HBx could increase the expression of 5-LOX through nuclear factor-ÎșB (NF-ÎșB). We also found that OPN could upregulate Capn4 through NF-ÎșB. Interestingly, we showed that Capn4 was able to upregulate OPN through NF-ÎșB in a positive feedback manner, suggesting that the OPN and Capn4 proteins involving cell migration affect each other in a network through NF-ÎșB. Importantly, NF-ÎșB plays a crucial role in the regulation of 5-LOX, OPN and Capn4. Thus, we conclude that HBx drives multiple cross-talk cascade loops involving NF-ÎșB, 5-LOX, OPN and Capn4 to promote cell migration. This finding provides new insight into the mechanism involving the promotion of cell migration by HBx

    Prognostic factors in metaplastic carcinoma of the breast: A multi-institutional study

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    Background: Metaplastic breast carcinoma (MBC) is a rare type of breast cancer that has basal-like characteristics and is perceived to have poorer prognosis when compared with conventional no specific type/ductal carcinomas (ductal/NST). However, current data on MBC are largely derived from small case series or population-based reports. This study aimed to assess the clinicopathological features and outcome of MBC identified through an international multicentre collaboration. Methods: A large international multicentre series of MBC (no=405) with histological confirmation and follow-up information has been included in this study. The prognostic value of different variables and outcome has been assessed and compared with grade, nodal status and ER/HER2 receptor-matched ductal/NST breast carcinoma. Results: The outcome of MBC diagnosed in Asian countries was more favourable than those in Western countries. The outcome of MBC is not different from matched ductal/NST carcinoma but the performance of the established prognostic variables in MBC is different. Lymph node stage, lymphovascular invasion and histologic subtype are associated with outcome but tumour size and grade are not. Chemotherapy was associated with longer survival, although this effect was limited to early-stage disease. In this study no association between radiotherapy and outcome was identified. Multivariate analysis of MBC shows that histologic subtype is an independent prognostic feature. Conclusions: This study suggests that MBC is a heterogeneous disease. Although the outcome of MBC is not different to matched conventional ductal/NST breast carcinoma, its behaviour is dependent on the particular subtype with spindle cell carcinoma in particular has an aggressive biological behaviour. Management of patients with MBC should be based on validated prognostic variables

    First Solar Orbiter observation of the Alfvénic slow wind and identification of its solar source

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    Context: Turbulence dominated by large amplitude nonlinear Alfvén-like fluctuations mainly propagating away from the Sun is ubiquitous in high speed solar wind streams. Recent studies have shown that also slow wind streams may show strong Alfvénic signatures, especially in the inner heliosphere. Aims: The present study focuses on the characterisation of an Alfvénic slow solar wind interval observed by Solar Orbiter on July 14-18, 2020 at a heliocentric distance of 0.64 AU. Methods: Our analysis is based on plasma moments and magnetic field measurements from the Solar Wind Analyser (SWA) and Magnetometer (MAG) instruments, respectively. We compare the behaviour of different parameters to characterise the stream in terms of the Alfvénic content and magnetic properties. We perform also a spectral analysis to highlight spectral features and waves signature using power spectral density and magnetic helicity spectrograms, respectively. Moreover, we reconstruct the Solar Orbiter magnetic connectivity to the solar sources via both a ballistic and a Potential Field Source Surface (PFSS) model. Results: The Alfvénic slow wind stream described in this paper resembles in many respects a fast wind stream. Indeed, at large scales, the time series of the speed profile shows a compression region, a main portion of the stream and a rarefaction region, characterised by different features. Moreover, before the rarefaction region, we pinpoint several structures at different scales recalling the spaghetti-like flux-tube texture of the interplanetary magnetic field. Finally, we identify the connections between Solar Orbiter in situ measurements, tracing them down to coronal streamer and pseudostreamer configurations. Conclusions. The characterisation of the Alfvénic slow wind stream observed by Solar Orbiter and the identification of its solar source are extremely important aspects to understand possible future observations of the same solar wind regime, especially as solar activity is increasing toward a maximum, where a higher incidence of this solar wind regime is expected

    Developing an Observing Air–Sea Interactions Strategy (OASIS) for the global ocean

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    The Observing Air–Sea Interactions Strategy (OASIS) is a new United Nations Decade of Ocean Science for Sustainable Development programme working to develop a practical, integrated approach for observing air–sea interactions globally for improved Earth system (including ecosystem) forecasts, CO2 uptake assessments called for by the Paris Agreement, and invaluable surface ocean information for decision makers. Our “Theory of Change” relies upon leveraged multi-disciplinary activities, partnerships, and capacity strengthening. Recommendations from >40 OceanObs’19 community papers and a series of workshops have been consolidated into three interlinked Grand Ideas for creating #1: a globally distributed network of mobile air–sea observing platforms built around an expanded array of long-term time-series stations; #2: a satellite network, with high spatial and temporal resolution, optimized for measuring air–sea fluxes; and #3: improved representation of air–sea coupling in a hierarchy of Earth system models. OASIS activities are organized across five Theme Teams: (1) Observing Network Design & Model Improvement; (2) Partnership & Capacity Strengthening; (3) UN Decade OASIS Actions; (4) Best Practices & Interoperability Experiments; and (5) Findable–Accessible–Interoperable–Reusable (FAIR) models, data, and OASIS products. Stakeholders, including researchers, are actively recruited to participate in Theme Teams to help promote a predicted, safe, clean, healthy, resilient, and productive ocean.publishedVersio
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