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Cranial electrotherapy stimulation and transcranial pulsed current stimulation: A computer based high-resolution modeling study

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NEUROIMAGE 2013年 65卷 280-287页

作者： Datta, Abhishek Dmochowski, Jacek P. Guleyupoglu, Berkan Bikson, Marom Fregni, Felipe CUNY City Coll Dept Biomed Engn Neural Engn Lab Grove Sch Engn New York NY 10031 USA Harvard Univ Sch Med Spaulding Rehabil Hosp Lab Neuromodulat Boston MA 02114 USA Harvard Univ Sch Med Beth Israel Deaconess Med Ctr Berenson Allen Ctr Noninvas Brain Stimulat Boston MA 02115 USA

The field of non-invasive brain stimulation has developed significantly over the last two decades. Though two techniques of noninvasive brain stimulation transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) are becoming established tools for research in neuroscience and for some clinical applications, related techniques that also show some promising clinical results have not been developed at the same pace. One of these related techniques is cranial electrotherapy stimulation (CES), a class of transcranial pulsed current stimulation (tPCS). In order to understand further the mechanisms of CES, we aimed to model CES using a magnetic resonance imaging (MRI)-derived finite element head model including cortical and also subcortical structures. Cortical electric field (current density) peak intensities and distributions were analyzed. We evaluated different electrode configurations of CES including in-ear and over-ear montages. Our results confirm that significant amounts of current pass the skull and reach cortical and subcortical structures. In addition, depending on the montage, induced currents at subcortical areas, such as midbrain, pons, thalamus and hypothalamus are of similar magnitude than that of cortical areas. Incremental variations of electrode position on the head surface also influence which cortical regions are modulated. The high-resolution modeling predictions suggest that details of electrode montage influence current flow through superficial and deep structures. Finally we present laptop based methods for tPCS dose design using dominant frequency and spherical models. These modeling predictions and tools are the first step to advance rational and optimized use of tPCS and CES. (C) 2012 Elsevier Inc. All rights reserved.

关键词： Cranial electrotherapy stimulation CES Brain stimulation computer based modeling Brainstem

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Interactions between urbanization, heat stress, and climate change

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CLIMATIC CHANGE 2015年第3-4期129卷 525-541页

作者： Oleson, K. W. Monaghan, A. Wilhelmi, O. Barlage, M. Brunsell, N. Feddema, J. Hu, L. Steinhoff, D. F. Natl Ctr Atmospher Res Boulder CO 80307 USA Univ Kansas Lawrence KS 66045 USA

Heat stress (HS) is a leading cause of weather-related human mortality. As temperatures continue to increase due to climate change, HS is expected to worsen. HS can be magnified in urban areas because of the urban heat island effect. We use an urban canyon model coupled to a land surface model to quantify present-day and projected mid-21st century rural and urban HS for boreal summer over the U.S. and southern Canada and examine the effects of three urban density classes on HS. Five indices of HS are implemented in the model [the NWS Heat Index (HI), Apparent Temperature (AT), Simplified Wet Bulb Globe Temperature, Humidex, and Discomfort Index]. The present-day urban-rural contrast in HS differs according to which index is used. The HI and Humidex have higher urban-rural HS for all density classes than defined by temperature alone. Future urban HS is amplified by 0.5-1.0 A degrees C for the AT, HI, and Humidex compared to temperature alone. For four cities examined in further detail, climate change by mid-century increases the number of high HS days and nights in both rural and urban areas, the magnitude being highly dependent on HS index, urban density class, and each city's climatic setting. Houston exhibits noteworthy mid-century increases in high heat stress nights, with more than half of summer nights qualifying as high HS in not only urban areas but also rural areas, indicating the need to consider vulnerability and adaptive capacity of both rural and urban populations in the context of climate change.

关键词： Climate change Urban areas Temperature Heat computer based modeling

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Inverse model for limited-area hindcasts on the continental shelf

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JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY 2001年第6期18卷 962-981页

作者： Lynch, DR Hannah, CG Dartmouth Coll Thayer Sch Engn Hanover NH 03755 USA Fisheries & Oceans Canada Bedford Inst Oceanog Dartmouth NS B2Y 4A2 Canada

The authors have constructed an inverse model for interpreting subtidal velocity observations in a limited-area hindcasting context. The intended use is following removal of a best prior circulation estimate that accounts for tide, local baroclinicity, and the direct response to local wind forcing. The remaining, subtidal velocity signal is inverted to provide far-field subtidal pressure forcing. The forward portion of the model is a linearization of a full-physics 3D simulator (QUODDY). Its inversion is achieved by gradient descent, using an exact algebraic adjoint and strong dynamical constraints. The cost function is a weighted least squares blend of velocity mismatch plus boundary condition size, slope, and tendency. The control parameters are barotropic open-water boundary conditions. Solution is achieved in the time domain, as a complement to the frequency-domain "detiding'' inversion presented earlier. A simple test case is introduced to demonstrate features of the inversion: precision, accuracy, interpolation, and extrapolation. A representative application on realistic topography (Georges Bank) is given.

关键词： computer based modeling Meteorology Velocity Atmosphere

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BioEarth: Envisioning and developing a new regional earth system model to inform natural and agricultural resource management

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CLIMATIC CHANGE 2015年第3-4期129卷 555-571页

作者： Adam, Jennifer C. Stephens, Jennie C. Chung, Serena H. Brady, Michael P. Evans, R. David Kruger, Chad E. Lamb, Brian K. Liu, Mingliang Stoeckle, Claudio O. Vaughan, Joseph K. Rajagopalan, Kirti Harrison, John A. Tague, Christina L. Kalyanaraman, Ananth Chen, Yong Guenther, Alex Leung, Fok-Yan Leung, L. Ruby Perleberg, Andrew B. Yoder, Jonathan Allen, Elizabeth Anderson, Sarah Chandrasekharan, Bhagyam Malek, Keyvan Mullis, Tristan Miller, Cody Nergui, Tsengel Poinsatte, Justin Reyes, Julian Zhu, Jun Choate, Janet S. Jiang, Xiaoyan Nelson, Roger Yoon, Jin-Ho Yorgey, Georgine G. Johnson, Kristen Chinnayakanahalli, Kiran J. Hamlet, Alan F. Nijssen, Bart Walden, Von Washington State Univ Pullman WA 99164 USA Clark Univ Worcester MA 01610 USA Washington State Univ Wenatchee WA USA Washington State Univ Vancouver WA USA Univ Calif Santa Barbara Santa Barbara CA 93106 USA Oregon State Univ Corvallis OR 97331 USA Pacific NW Natl Lab Richland WA 99352 USA Natl Ctr Atmospher Res Boulder CO 80307 USA Washington State Univ Seattle WA USA AIRWorldwide Boston MA USA Notre Dame Univ Notre Dame IN USA Univ Washington Seattle WA 98195 USA

As managers of agricultural and natural resources are confronted with uncertainties in global change impacts, the complexities associated with the interconnected cycling of nitrogen, carbon, and water present daunting management challenges. Existing models provide detailed information on specific sub-systems (e.g., land, air, water, and economics). An increasing awareness of the unintended consequences of management decisions resulting from interconnectedness of these sub-systems, however, necessitates coupled regional earth system models (EaSMs). Decision makers' needs and priorities can be integrated into the model design and development processes to enhance decision-making relevance and "usability" of EaSMs. BioEarth is a research initiative currently under development with a focus on the U.S. Pacific Northwest region that explores the coupling of multiple stand-alone EaSMs to generate usable information for resource decision-making. Direct engagement between model developers and non-academic stakeholders involved in resource and environmental management decisions throughout the model development process is a critical component of this effort. BioEarth utilizes a bottom-up approach for its land surface model that preserves fine spatial-scale sensitivities and lateral hydrologic connectivity, which makes it unique among many regional EaSMs. This paper describes the BioEarth initiative and highlights opportunities and challenges associated with coupling multiple stand-alone models to generate usable information for agricultural and natural resource decision-making.

关键词： Climate change Agriculture computer based modeling

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Understanding tDCS effects in schizophrenia: a systematic review of clinical data and an integrated computation modeling analysis

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EXPERT REVIEW OF MEDICAL DEVICES 2014年第4期11卷 383-394页

作者： Brunoni, Andre R. Shiozawa, Pedro Truong, Dennis Javitt, Daniel C. Elkis, Helio Fregni, Felipe Bikson, Marom Univ Sao Paulo Dept & Inst Psychiat Sao Paulo Brazil Univ Sao Paulo SIN Sao Paulo Brazil Univ Sao Paulo CINA Sao Paulo Brazil Univ Sao Paulo Inst Psychiat Lab Neurosci LIM 27 Sao Paulo Brazil Santa Casa Med Sch Lab Clin Neuromodulat Sao Paulo Brazil CUNY CCNY Dept Biomed Engn New York NY USA Columbia Coll Phys & Surg Div Expt Therapeut Dept Psychiat New York NY USA Harvard Univ Sch Med Spaulding Rehabil Hosp Lab Neuromodulat Boston MA USA

Although recent clinical studies using transcranial direct current stimulation (tDCS) for schizophrenia showed encouraging results, several tDCS montages were employed and their current flow pattern has not been investigated. We performed a systematic review to identify clinical tDCS studies in schizophrenia. We then applied computer head modeling analysis for prediction of current flow. Out of 41 references, we identified 12 relevant studies. The most employed montage was anode and cathode over the left dorsolateral prefrontal and temporoparietal cortex, respectively. Computational model analysis predicted activation and under-activation under the anode and the cathode, respectively, occurring in areas respectively associated with negative and positive symptoms. We also identified tDCS-induced electrical currents in cortical areas between the electrodes (frontoparietal network) and, to a lesser extent, in deeper structures involved in schizophrenia pathophysiology. Mechanisms of tDCS effects in schizophrenia and the usefulness of computer modeling techniques for planning tDCS trials in schizophrenia are discussed.

关键词： auditory hallucinations computer based modeling non-invasive brain stimulation schizophrenia transcranial direct current stimulation

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Weather support for the 2002 Winter Olympic and Paralympic Games

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BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY 2002年第2期83卷 227-+页

作者： Horel, J Potter, T Dunn, L Steenburgh, WJ Eubank, M Splitt, M Onton, DJ Univ Utah NOAA Cooperat Inst Reg Predict Salt Lake City UT 84112 USA Salt Lake City Weather Forecast Off Salt Lake City UT USA KSL Salt Lake City UT USA

The 2002 Winter Olympic and Paralympic Games will be hosted by Salt Lake City, Utah, during February-March 2002. Adverse weather during this period may delay sporting events, while snow and ice-covered streets and highways may impede access by the athletes and spectators to the venues. While winter snowstorms and other large-scale weather systems typically have widespread impacts throughout northern Utah, hazardous winter weather is often related to local terrain features (the Wasatch Mountains and Great Salt Lake are the most prominent ones). Examples of such hazardous weather include lake-effect snowstorms, ice fog, gap winds, downslope windstorms, and low visibility over mountain passes. A weather support system has been developed to provide weather information to the athletes, games officials, spectators, and the interested public around the world. This system is managed by the Salt Lake Olympic Committee and relies upon meteorologists from the public, private, and academic sectors of the atmospheric science community. Weather forecasting duties will be led by National Weather Service forecasters and a team of private weather forecasters organized by KSL, the Salt Lake City NBC television affiliate. Other government agencies, commercial firms, and the University of Utah are providing specialized forecasts and support services for the Olympics. The weather support system developed for the 2002 Winter Olympics is expected to provide long-term benefits to the public through improved understanding, monitoring, and prediction of winter weather in the Intermountain West.

关键词： Weather Meteorology computer based modeling Olympic games-2002

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Impact of Atlantic SST and high frequency atmospheric variability on the 1993 and 2008 Midwest floods: Regional climate model simulations of extreme climate events

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CLIMATIC CHANGE 2015年第3-4期129卷 397-411页

作者： Patricola, Christina M. Chang, Ping Saravanan, R. Texas A&M Univ Dept Atmospher Sci College Stn TX 77843 USA Texas A&M Univ Dept Oceanog College Stn TX 77843 USA Ocean Univ China Phys Oceanog Lab Qingdao Peoples R China

The role of sea surface temperature anomalies (SSTAs) in the Atlantic and eastern Pacific and high-frequency atmospheric variability from the Pacific during the 1993 and 2008 Midwest floods is investigated with a regional climate model. The SSTAs insignificantly modulate Midwest rainfall during the 1993 flood, but enhance precipitation during the 2008 peak flood by strengthening the southern portion of the Great Plains low-level jet, enhancing moisture transport from the Gulf of Mexico into the Midwest. This work suggests that while North Atlantic SST strongly controls Midwest decadal drought and pluvial periods, it plays a minimal or secondary role in modulating extreme flood events lasting weeks to months. A negative Pacific/North American (PNA) teleconnection marked the peak of both floods, suggesting a link between extreme Midwest warm season rainfall and high-frequency PNA variations. Simulations that apply a 10-day low-pass filter to the western lateral boundary condition indicate that interactions between the eddy and time-mean flow played a significant, but counterintuitive role, during the 1993 flood. Although above normal Pacific cyclone activity was observed to trigger heavy Midwest precipitation, the synoptic eddies also indirectly influenced rainfall by modifying the time-mean circulation. Simulations show that eddies from the Pacific dampened the positive rainfall anomalies by weakening vertically integrated moisture transport and upper level divergence anomalies over the Midwest.

关键词： Climate change Atmosphere Floods Simulation computer based modeling

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modeling radionuclide migration in complex nonuniform water bodies using the POMRad model system

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RUSSIAN METEOROLOGY AND HYDROLOGY 2014年第1期39卷 29-37页

作者： Krylov, A. L. Nosov, A. V. Kiselev, V. P. Russian Acad Sci Inst Atom Energy Dev Safety Problems Moscow 115191 Russia

The POMRad system of computer models is developed using the Princeton Ocean Model (POM) program code. The system enables modeling the radionuclide migration in large nonuniform water bodies (seas, bays, large rivers, and lakes) taking account of the migration of radioactive substances in the water mass-bottom system associated with the migration of radionuclides sorbed on suspended sediments and in solutes. In order to take account of radionucide transport with sediments the POM program code is supplemented with the models describing transport, settling, and resuspension of suspended sediments. The verification was carried out through comparing analytical solutions of simplified problems concerning the content of radionuclides in water, and modeling results. A potential of the POMRad application is demonstrated by an example of simulating the radioactivity transport in marine environment in the case of hypothetical accidents in the Saida and Kola bays.

关键词： computer based modeling Radioactivity Hydrology

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Investigating the nexus of climate, energy, water, and land at decision-relevant scales: the Platform for Regional Integrated modeling and Analysis (PRIMA)

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CLIMATIC CHANGE 2015年第3-4期129卷 573-588页

作者： Kraucunas, Ian Clarke, Leon Dirks, James Hathaway, John Hejazi, Mohamad Hibbard, Kathy Huang, Maoyi Jin, Chunlian Kintner-Meyer, Michael van Dam, Kerstin Kleese Leung, Ruby Li, Hong-Yi Moss, Richard Peterson, Marty Rice, Jennie Scott, Michael Thomson, Allison Voisin, Nathalie West, Tristram Pacific NW Natl Lab Richland WA 99352 USA

The Platform for Regional Integrated modeling and Analysis (PRIMA) is an innovative modeling system developed at Pacific Northwest National Laboratory (PNNL) to simulate interactions among natural and human systems at scales relevant to regional decision making. PRIMA brings together state-of-the-art models of regional climate, hydrology, agriculture and land use, socioeconomics, and energy systems using a flexible coupling approach. Stakeholder decision support needs underpin the application of the platform to regional issues, and an uncertainty characterization process is used to identify robust decisions. The platform can be customized to inform a variety of complex questions, such as how a policy in one sector might affect the ability to meet climate mitigation targets or adaptation goals in another sector. Current numerical experiments focus on the eastern United States, but the framework is designed to be regionally flexible. This paper provides a high-level overview of PRIMA's functional capabilities and describes some key challenges and opportunities associated with integrated regional modeling.

关键词： Climate change computer based modeling Hydrology

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Connection between Eurasian and North Atlantic Climate Anomalies and Natural Variations in the Atlantic Thermohaline Circulation based on Long-Term Model Calculations

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DOKLADY EARTH SCIENCES 2008年第2期419卷 502-505页

作者： Mokhov, I. I. Semenov, V. A. Khon, V. Ch. Latif, M. Roeckner, E. Russian Acad Sci Oboukhov Inst Atmospher Phys Moscow 119017 Russia Univ Kiel Leibniz Inst Marine Sci D-24105 Kiel Germany Max Planck Inst Meteorol D-20146 Hamburg Germany

The authors obtained estimates of the correlation between regional characteristics of the climate in Eurasia and the North Atlantic and the Atlantic thermohaline circulation (ATHC) based on the results of calculations using the ocean-atmosphere global climate model (OAGCM) without external forcing (reference numerical experiment) for the period of 500 yr. The regions of statistically signicant correlation between the ATHC variations in a few decades with the anomalies of surface air temperature, pressure at sea level, and precipitation in different seasons were distinguished. The most significant correlation was found in the winter period. A correlation was also found between the ATHC and the intensity of the Iceland minimum of the atmospheric action center (AC) [1], which has a strong influence on the weather conditions in Europe.

关键词： Oceans Atmosphere Climate computer based modeling Geophysics Temperature Studies

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