143 research outputs found

    The strategies preventing particle transportation into the inlets of nuclear power plants: Mechanisms of physical oceanography

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    The formation of aquatic organism aggregations near the inlets of nuclear power plants (NPPs) has become an important global concern, as the aggregated organisms can block the cooling systems of NPPs, and, therefore, threaten their operational safety. In this study we focus on the trajectory of aquatic organisms, that is., how these organisms can be transported to the inlets of NPPs by physical ocean processes related to currents and waves. The Changjiang NPP, located on the west side of Hainan Island in China, is occasionally subject to serious gulfweed blocking events in spring. To study the physical mechanism, with the use of a three-dimensional numerical current–wave-coupled model, the current and wave conditions near the NPP were simulated. Based on the model, several particle-tracking simulations were run to evaluate the extent of the blocking that occurred in the inlet of the NPP’s cooling system with different forcings introduced. The results showed that the windage effect and the surface Stokes drift induced by waves were the main causes of blocking events in the Changjiang NPP, with the former transporting surface particles from upstream and the latter transporting surrounding particles onshore, into the NPP’s inlet. Further simulations revealed that bending of the inlet and changing the offshore mouth to downstream mouth could limit the blocking greatly, as particles were seldom transported into the mouth by cross-shore transport processes such as the Stokes drift. We suggest that such findings may provide a valuable reference for the development of strategies to prevent aquatic organism aggregation events in other NPPs

    The coastal ocean response to the global warming acceleration and hiatus

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    本研究揭示了全球沿岸对目前全球气候变暖减缓背景下的不同的区域响应,有助于理解全球增暖减缓现象的潜在机理,并为近期发生在各个海岸地区的极端热和极端冷的事件提供了更好的理解,有助于灾害防治和生态保护的政策制定。【Astract】Coastlines are fundamental to humans for habitation, commerce, and natural resources. Many coastal ecosystem disasters, caused by extreme sea surface temperature (SST), were reported when the global climate shifted from global warming to global surface warming hiatus after 1998. The task of understanding the coastal SST variations within the global context is an urgent matter. Our study on the global coastal SST from 1982 to 2013 revealed a significant cooling trend in the low and mid latitudes (31.4% of the global coastlines) after 1998, while 17.9% of the global coastlines changed from a cooling trend to a warming trend concurrently. The trend reversals in the Northern Pacific and Atlantic coincided with the phase shift of Pacific Decadal Oscillation and North Atlantic Oscillation, respectively. These coastal SST changes are larger than the changes of the global mean and open ocean, resulting in a fast increase of extremely hot/cold days, and thus extremely hot/cold events. Meanwhile, a continuous increase of SST was detected for a considerable portion of coastlines (46.7%) with a strengthened warming along the coastlines in the high northern latitudes. This suggests the warming still continued and strengthened in some regions after 1998, but with a weaker pattern in the low and mid latitudes.该研究工作获得了中国国家自然基金委、福建省和美国NOAA-Sea Grant 的资助

    International Consensus Recommendations for the Treatment of Pediatric NMDAR Antibody Encephalitis

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    To create an international consensus treatment recommendation for pediatric NMDA receptor antibody encephalitis (NMDARE).After selection of a panel of 27 experts with representation from all continents, a 2-step Delphi method was adopted to develop consensus on relevant treatment regimens and statements, along with key definitions in pediatric NMDARE (disease severity, failure to improve, and relapse). Finally, an online face-to-face meeting was held to reach consensus (defined as ?75% agreement).Corticosteroids are recommended in all children with NMDARE (pulsed IV preferred), with additional IV immunoglobulin or plasma exchange in severe patients. Prolonged first-line immunotherapy can be offered for up to 3-12 months (oral corticosteroids or monthly IV corticosteroids/immunoglobulin), dependent on disease severity. Second-line treatments are recommended for cases refractory to first-line therapies (rituximab preferred over cyclophosphamide) and should be considered about 2 weeks after first-line initiation. Further immunotherapies for refractory disease 1-3 months after second-line initiation include another second-line treatment (such as cyclophosphamide) and escalation to tocilizumab. Maintenance immune suppression beyond 6 months (such as rituximab redosing or mycophenolate mofetil) is generally not required, except for patients with a more severe course or prolonged impairments and hospitalization. For patients with relapsing disease, second-line and prolonged maintenance therapy should be considered. The treatment of NMDARE following herpes simplex encephalitis should be similar to idiopathic NMDARE. Broad guidance is provided for the total treatment duration (first line, second line, and maintenance), which is dictated by the severity and clinical course (i.e., median 3, 9 and 18 months in the best, average, and worst responders, respectively). Recommendations on the timing of oncologic searches are provided.These international consensus recommendations for the management of pediatric NMDARE aim to standardize the treatment and provide practical guidance for clinicians, rather than absolute rules. A similar recommendation could be applicable to adult patients.Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology

    SYNGAP1 encephalopathy:A distinctive generalized developmental and epileptic encephalopathy

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    Objective To delineate the epileptology, a key part of the SYNGAP1 phenotypic spectrum, in a large patient cohort. Methods Patients were recruited via investigators' practices or social media. We included patients with (likely) pathogenic SYNGAP1 variants or chromosome 6p21.32 microdeletions incorporating SYNGAP1. We analyzed patients' phenotypes using a standardized epilepsy questionnaire, medical records, EEG, MRI, and seizure videos. Results We included 57 patients (53% male, median age 8 years) with SYNGAP1 mutations (n = 53) or microdeletions (n = 4). Of the 57 patients, 56 had epilepsy: generalized in 55, with focal seizures in 7 and infantile spasms in 1. Median seizure onset age was 2 years. A novel type of drop attack was identified comprising eyelid myoclonia evolving to a myoclonic-atonic (n = 5) or atonic (n = 8) seizure. Seizure types included eyelid myoclonia with absences (65%), myoclonic seizures (34%), atypical (20%) and typical (18%) absences, and atonic seizures (14%), triggered by eating in 25%. Developmental delay preceded seizure onset in 54 of 56 (96%) patients for whom early developmental history was available. Developmental plateauing or regression occurred with seizures in 56 in the context of a developmental and epileptic encephalopathy (DEE). Fifty-five of 57 patients had intellectual disability, which was moderate to severe in 50. Other common features included behavioral problems (73%); high pain threshold (72%); eating problems, including oral aversion (68%); hypotonia (67%); sleeping problems (62%); autism spectrum disorder (54%); and ataxia or gait abnormalities (51%). Conclusions SYNGAP1 mutations cause a generalized DEE with a distinctive syndrome combining epilepsy with eyelid myoclonia with absences and myoclonic-atonic seizures, as well as a predilection to seizures triggered by eating.</p

    Three-dimensional structure of a low salinity tongue in the southern Taiwan Strait observed in the summer of 2005

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    Cruise observations with CTD (conductivity-temperature-depth) profiler were carried out in the southern Taiwan Strait in the summer of 2005. Using the cruise data, two-dimensional maps of salinity and temperature distributions at depths of 5, 10, 15, 20, and 30 m were generated. The maps show a low salinity tongue sandwiched by low temperature and high salinity waters on the shallow water side and high temperature and high salinity waters on the deep water side. The further analysis indicates that the low salinity water has a nature of river-diluted water. A possible source of the diluted water is the Zhujiang (Pearl) Estuary. Meanwhile, the summer monsoon is judged as a possible driving force for this northeastward jet-like Current. The coastal upwelling and the South China Sea Warm Current confine the low salinity water to flow along the central line of the strait. Previous investigations and a numerical model are used to verify that the upstream of the low salinity current is the Zhujiang Estuary. Thus, the low salinity tongue is produced by four major elements: Zhujinag Estuary diluted water, monsoon wind driving, coastal upwelling and South China Sea Warm Current modifications.National Natural Science Foundation of China [40331004, 40576015, 40810069004, 40821063]; MEL Open Project [MEL0506]; ONR [N00014-05-1-0328, N00014-05-1-0606]; NSF [071003-9222

    Modeling the Total Allowable Area for Coastal Reclamation : a case study of Xiamen, China

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    Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Ocean & Coastal Management 76 (2013):38-44, doi:10.1016/j.ocecoaman.2013.02.015.This paper presents an analytical framework to estimate the Total Allowable Area for Coastal Reclamation (TAACR) to provide scientific support for the implementation of a coastal reclamation restriction mechanism. The logic of the framework is to maximize the net benefits of coastal reclamation subject to a set of constraints. Various benefits and costs, including the ecological and environmental costs of coastal reclamation, are systematically quantified in the framework. Model simulations are developed using data from Tongan Bay of Xiamen. The results suggest that the TAACR in Tongan Bay is 5.67 km2, and the area of the Bay should be maintained at least at 87.52 km2.The study was funded by the National Oceanic Public Welfare Projects (No. 201105006) and the Fujian Natural Science Foundation (No. 2010J01360

    New insight into smart ocean: how is it different from digital ocean?

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    Oceans occupy approximately seventy-one percent of the earth’s surface, and vast regions of oceans are virtually unexplored, especially the deep parts where humans have never been. Therefore, it is urgent to understand our oceans from a number of perspectives. In this paper, the concept of Smart Ocean (SO) is constructed from the perspectives of environmental protection, sustainable development of the blue economy and marine disaster prevention and mitigation. First, a double-funnel structure concept model of SO, including ocean observation infrastructure, data, information, application, knowledge and decision support layers, is put forward. Second, the differences between SO and Digital Ocean (DO) are analyzed. Third, taking the Decision Support System for Emergency at Taiwan Strait as an example, a case study, which has assisted in saving more than 200 people, is introduced. Finally, future research agenda is summarized into seven aspects, including new instrumentation and sensor technologies, ocean big data mining and knowledge discovering, prediction, forecast and uncertainty analysis, ocean environment protection technologies and policy, sustainable use of ocean energy and resource, the influence and response to global changes in the ocean, and interdisciplinary collaboration and public service

    Comparing Statistical and Semi-Distributed Rainfall–Runoff Models for a Large Subtropical Watershed: A Case Study of Jiulong River Catchment, China

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    In this contribution, the authors present their preliminary investigations into modeling the rainfall&#8315;runoff generation relation in a large subtropical catchment (Jiulong River catchment) on the southeast coast of China. Previous studies have mostly focused on modeling the streamflow and water quality of its small rural subcatchments. However, daily runoff on the scale of the whole catchment has not been modeled before, and hourly runoff data are desirable for some oceanographic applications. Three methods are proposed for modeling streamflow using rainfall outputted by the Weather Research Forecast (WRF) model, calculated potential evaporation (PET), and land cover type: (i) a ridge regression model; (ii) NPRED-KNN: a nonparametric k-nearest neighbor model (KNN) employing a parameter selection method (NPRED) based on partial information coefficient; (iii) the Hydrological Simulation Program-Fortran (HSPF) model with an hourly time step. Results show that the NPRED-KNN approach is the most unsuitable method of those tested. The HSPF model was manually calibrated, and ridge regression performs no worse than HSPF based on daily verification, whilst HSPF can produce realist daily flow time series, of which ridge regression is incapable. The HSPF model seems less prone to systematic underprediction when replicating monthly-annual water balance, and it successfully replicates the baseflow index (the flow intensity) of the Jiulong River catchment system
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