scholarly journals Modeling Epidemic Spread among a Commuting Population Using Transport Schemes

Mathematics ◽  
2021 ◽  
Vol 9 (16) ◽  
pp. 1861
Author(s):  
Daniela Calvetti ◽  
Alexander P. Hoover ◽  
Johnie Rose ◽  
Erkki Somersalo
Keyword(s):  
Network Model ◽  
Transport Theory ◽  
Optimal Transport ◽  
State Level ◽  
Compartment Model ◽  
Census Bureau ◽  
Mitigation Strategies ◽  
Mitigation Measures ◽  
Metapopulation Model ◽  
Infection Dynamics

Understanding the dynamics of the spread of COVID-19 between connected communities is fundamental in planning appropriate mitigation measures. To that end, we propose and analyze a novel metapopulation network model, particularly suitable for modeling commuter traffic patterns, that takes into account the connectivity between a heterogeneous set of communities, each with its own infection dynamics. In the novel metapopulation model that we propose here, transport schemes developed in optimal transport theory provide an efficient and easily implementable way of describing the temporary population redistribution due to traffic, such as the daily commuter traffic between work and residence. Locally, infection dynamics in individual communities are described in terms of a susceptible-exposed-infected-recovered (SEIR) compartment model, modified to account for the specific features of COVID-19, most notably its spread by asymptomatic and presymptomatic infected individuals. The mathematical foundation of our metapopulation network model is akin to a transport scheme between two population distributions, namely the residential distribution and the workplace distribution, whose interface can be inferred from commuter mobility data made available by the US Census Bureau. We use the proposed metapopulation model to test the dynamics of the spread of COVID-19 on two networks, a smaller one comprising 7 counties in the Greater Cleveland area in Ohio, and a larger one consisting of 74 counties in the Pittsburgh–Cleveland–Detroit corridor following the Lake Erie’s American coastline. The model simulations indicate that densely populated regions effectively act as amplifiers of the infection for the surrounding, less densely populated areas, in agreement with the pattern of infections observed in the course of the COVID-19 pandemic. Computed examples show that the model can be used also to test different mitigation strategies, including one based on state-level travel restrictions, another on county level triggered social distancing, as well as a combination of the two.

scholarly journals Mitigation Strategies and Compliance in the Covid-19 Fight; How Much Compliance is Enough?

2020 ◽  
Author(s):  
Swati Mukerjee ◽  
Clifton Chow ◽  
Mingfei Li
Keyword(s):  
New York ◽  
State Level ◽  
Mitigation Strategies ◽  
Mitigation Measures ◽  
Policy Makers ◽  
Time Dynamic ◽  
Policy Tool ◽  
Daily Data ◽  
Suitable Combination ◽  
The U.S

Today, with only 4% of the world's population, the U.S. is bearing a disproportionate share of COVID-19 infections. Seeking to understand this puzzle, we investigate how mitigation strategies and compliance can work together (or in opposition) to reduce (or increase) the spread of COVID-19 infection. Drilling down to the state level, we create specific state indices suitable for the U.S. to measure the degree of strictness of public mitigation measures. In this, we build on the Oxford Stringency Index. A modified time-varying SEIRD model, incorporating this Stringency Index as well as a Compliance Indicator to reduce the transmission, is then estimated with daily data for a sample of 6 U.S. states. These are New York, New Hampshire, New Mexico, Colorado, Texas, and Arizona. We provide a simple visual policy tool to evaluate the various combinations of mitigation policies and compliance that can reduce the basic reproduction number to less than one; this is the acknowledged threshold in the epidemiological literature to control the pandemic. States successful in combating the pandemic were able to achieve a suitable combination. Understanding of this relationship by the public and policy makers is key to controlling the pandemic. This tool has the potential to be used in a real-time, dynamic fashion for flexible policy options.

Pharmacokinetics and Effects on Fibrinolytic and Coagulation Parameters of Two Doses of Recombinant Tissue-Type Plasminogen Activator in Healthy Volunteers

1986 ◽  
Vol 56 (01) ◽  
pp. 001-005 ◽  
Author(s):  
M Verstraete ◽  
C A P F Su ◽  
P Tanswell ◽  
W Feuerer ◽  
D Collen
Keyword(s):  
Healthy Volunteers ◽  
Plasminogen Activator ◽  
Degradation Products ◽  
Plasma Concentrations ◽  
State Level ◽  
Compartment Model ◽  
Tissue Type ◽  
Maximum Plasma ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator

SummaryPharmacokinetics and pharmacological effects of two intravenous doses of recombinant tissue-type plasminogen activator (rt-PA) (40 and 60 mg over 90 min) were determined in healthy volunteers. Mean maximum plasma concentrations were 1080 and 1560 ng/ml respectively. The steady state level during subsequent maintenance infusion of 30 mg over 6 h was 250 ng/ml. The pharmacokinetics of rt-PA showed a bi-exponential disappearance from plasma consistent with a 2-compartment model of t½α = 5.7 min, a t½β = 1.3 h and a total clearance of 380 ml/min.Mean fibrinogen levels at the end of the infusions of 40 mg or 60 mg rt-PA over 90 min, measured in thawed plasma samples collected on citrate/aprotinin, decreased to 74% and 57% of the preinfusion values respectively. Plasminogen fell to 55% and 48%, and α2-antiplasmin to 28% and 18% of initial values. No further decrease of these parameters was observed during the infusion of 30 mg rt-PA over 6 h. Only 2% of the preinfusion fibrinogen levels could be recovered as fibrinogen-fibrin degradation products. This moderate extent of systemic fibrinogenolysis is much less than that reported for therapeutic i.v. infusions of streptokinase.

scholarly journals Design of COVID-19 staged alert systems to ensure healthcare capacity with minimal closures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Haoxiang Yang ◽  
Özge Sürer ◽  
Daniel Duque ◽  
David P. Morton ◽  
Bismark Singh ◽  
...  
Keyword(s):  
Hospital Admissions ◽  
Optimal Strategies ◽  
Mitigation Strategies ◽  
Mitigation Measures ◽  
Public Confidence ◽  
Proof Of Concept ◽  
Alert System ◽  
System Safety ◽  
Reducing Costs ◽  
Restrictive Measures

AbstractCommunity mitigation strategies to combat COVID-19, ranging from healthy hygiene to shelter-in-place orders, exact substantial socioeconomic costs. Judicious implementation and relaxation of restrictions amplify their public health benefits while reducing costs. We derive optimal strategies for toggling between mitigation stages using daily COVID-19 hospital admissions. With public compliance, the policy triggers ensure adequate intensive care unit capacity with high probability while minimizing the duration of strict mitigation measures. In comparison, we show that other sensible COVID-19 staging policies, including France’s ICU-based thresholds and a widely adopted indicator for reopening schools and businesses, require overly restrictive measures or trigger strict stages too late to avert catastrophic surges. As proof-of-concept, we describe the optimization and maintenance of the staged alert system that has guided COVID-19 policy in a large US city (Austin, Texas) since May 2020. As cities worldwide face future pandemic waves, our findings provide a robust strategy for tracking COVID-19 hospital admissions as an early indicator of hospital surges and enacting staged measures to ensure integrity of the health system, safety of the health workforce, and public confidence.

scholarly journals Wildlife Monitoring Using a Multi-UAV System with Optimal Transport Theory

2021 ◽  
Vol 11 (9) ◽  
pp. 4070
Author(s):  
Rabiul Hasan Kabir ◽  
Kooktae Lee
Keyword(s):  
Detection Rate ◽  
Transport Theory ◽  
Optimal Transport ◽  
Position Estimation ◽  
Wildlife Monitoring ◽  
High Detection Rate ◽  
Monitoring Strategies ◽  
Spatio Temporal ◽  
Optimal Transport Theory ◽  
Multi Uav

This paper addresses a wildlife monitoring problem using a team of unmanned aerial vehicles (UAVs) with the optimal transport theory. The state-of-the-art technology using UAVs has been an increasingly popular tool to monitor wildlife compared to the traditional methods such as satellite imagery-based sensing or GPS trackers. However, there still exist unsolved problems as to how the UAVs need to cover a spacious domain to detect animals as many as possible. In this paper, we propose the optimal transport-based wildlife monitoring strategy for a multi-UAV system, to prioritize monitoring areas while incorporating complementary information such as GPS trackers and satellite-based sensing. Through the proposed scheme, the UAVs can explore the large-size domain effectively and collaboratively with a given priority. The time-varying nature of wildlife due to their movements is modeled as a stochastic process, which is included in the proposed work to reflect the spatio-temporal evolution of their position estimation. In this way, the proposed monitoring plan can lead to wildlife monitoring with a high detection rate. Various simulation results including statistical data are provided to validate the proposed work. In all different simulations, it is shown that the proposed scheme significantly outperforms other UAV-based wildlife monitoring strategies in terms of the target detection rate up to 3.6 times.

scholarly journals Assessing Soil Loss by Water Erosion in a Typical Mediterranean Ecosystem of Northern Greece under Current and Future Rainfall Erosivity

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2002
Author(s):  
Stefanos Stefanidis ◽  
Vasileios Alexandridis ◽  
Chrysoula Chatzichristaki ◽  
Panagiotis Stefanidis
Keyword(s):  
Open Source ◽  
Soil Loss ◽  
Renewable Resource ◽  
Mitigation Strategies ◽  
Mitigation Measures ◽  
Mediterranean Ecosystem ◽  
Rainfall Erosivity ◽  
Negative Consequences ◽  
Northern Greece ◽  
Erosion Risk

Soil is a non-renewable resource essential for life existence. During the last decades it has been threatened by accelerating erosion with negative consequences for the environment and the economy. The aim of the current study was to assess soil loss changes in a typical Mediterranean ecosystem of Northern Greece, under climate change. To this end, freely available geospatial data was collected and processed using open-source software package. The widespread RUSLE empirical erosion model was applied to estimate soil loss. Current and future rainfall erosivity were derived from a national scale study considering average weather conditions and RCMs outputs for the medium Representative Concentration Pathway scenario (RCP4.5). Results showed that average rainfall erosivity (R-Factor) was 508.85 MJ mm ha h−1 y−1 while the K-factor ranged from 0.0008 to 0.05 t ha h ha−1 MJ−1 mm−1 and LS-factor reached 60.51. Respectively, C-factor ranged from 0.01 to 0.91 and P-factor ranged from 0.42 to 1. The estimated potential soil loss rates will remain stable for the near future period (2021–2050), while an increase of approximately 9% is expected by the end of the 21th century (2071–2100). The results suggest that appropriate erosion mitigation strategies should be applied to reduce erosion risk. Subsequently, appropriate mitigation measures per Land Use/Land Cover (LULC) categories are proposed. It is worth noting that the proposed methodology has a high degree of transferability as it is based on open-source data.

Schrödinger dynamics and optimal transport of measures

2021 ◽  
pp. 2150016
Author(s):  
Lorenzo Zanelli
Keyword(s):  
Schrödinger Equation ◽  
Schrodinger Equation ◽  
Transport Theory ◽  
Optimal Transport ◽  
Time Dependent ◽  
Probability Measures ◽  
Flat Torus ◽  
Optimal Transport Theory

In this paper, we recover a class of displacement interpolations of probability measures, in the sense of the Optimal Transport theory, by means of semiclassical measures associated with solutions of Schrödinger equation defined on the flat torus. Moreover, we prove the completing viewpoint by proving that a family of displacement interpolations can always be viewed as a path of time-dependent semiclassical measures.

Emerging mitigation measures and strategies are needed for riverine ecology to ensure sustainable hydropeaking production in Norway 

2021 ◽  
Author(s):  
Jo Halvard Halleraker ◽  
Mahmoud S. R. Kenawi ◽  
Jan Henning L’Abée - Lund ◽  
Anders G. Finstad ◽  
Knut Alfredsen
Keyword(s):  
Biological Indicators ◽  
Ecological Impacts ◽  
Mitigation Strategies ◽  
Mitigation Measures ◽  
National Database ◽  
Political Agenda ◽  
Regulated Rivers ◽  
Hydropower Production ◽  
Multiple Pressures ◽  
Environmental Requirements

<p><strong>Riverine biodiversity</strong> is threatened with severe degradation from multiple pressures worldwide. One of the key pressures in European rivers are hydromorphological alterations. Rehabilitation of river habitats is accordingly high on the political agenda at the start of UN decade of ecological restoration (2021-2030).</p><p><strong>Water storage</strong> for hydropower production (HP) has severe impacts on aquatic ecology in Norway, with more than 3000 water bodies designated as heavily modified due to hydropower. Norway is the largest hydropower producer in Europe with a huge amount of high head storage schemes. Ca 86 TWh of this is storage hydropower, which constitutes more than 50% of the total in Europe. This makes Norway a potentially significant supplier of hydropeaking services. Flexible hydropower operations are crucial for EUs Green Deal in balancing electricity from renewable intermittent power generation such as wind and solar. </p><p>Many Norwegian <strong>HP licenses</strong> were issued before modern environmental requirements evolved. Few are re-licensed with emerging strategies to mitigate hydropeaking. Still, there seems to be a common understanding of relevant mitigation strategies emerging between many large hydropower producers. For example, flow ramping from hydropower tailrace water with direct outlet into fjords or other lake reservoirs may be less environmentally harmful than outlet into riverine habitat.In this study, we have assessed the Norwegian hydropower portfolio of more than 1600 HP facilities constructing a national database focusing on the knowledge base for assessing potential downstream hydropower ecological impacts. The ecological severity of such flow ramping and the restoration/mitigation potential, may depend on;</p><p> </p><p>About 51 % of the HPs (ca<strong> 80TWh</strong>) have tailrace into shorter rivers (<1 km) or directly into fjords or lake/reservoirs. Many of the largest HPs are in this category (e.g 50 HP> 500 MW). Close to 800 HP might have downstream impacts on rivers (> 0.5 km; about 49 % of all HP, in total of ca<strong> 56 TWh</strong>). Probably <strong>> 3 000 km of regulated rivers</strong> in Norway therefor might need more ecosystem-based mode of HP operation. <strong>Flow ramping analysis: </strong> Ecosystem-based HP operational rules are established in a selection of sustainably managed Norwegian rivers, still with significant baseload production (0.35-0.76 - TWh annual prod). However, eco-friendly mode of operation seems to be rare as our analysis indicate that flow ramping with potential ecological degradation seems widespread in many rivers. Surprisingly, even in many with operational ramping restriction as required mitigation.Our database may be further improved and updated (with e.g. more flow ramping data and biological indicators) and serve as a basis for a national hydropeaking strategy, and hence make more of the Norwegian hydropower portfolio in line with the EUs sustainability taxonomy.</p>

scholarly journals Questionable Reform: The Adoption of the Double-Entry Bookkeeping and Accrual Basis Accounting System in Korea

2018 ◽  
Vol 33 (1) ◽  
pp. 57-80
Author(s):  
Im Tobin ◽  
Lee Hyunkuk ◽  
Lim Dongwan
Keyword(s):  
Physical Properties ◽  
Natural Disasters ◽  
State Level ◽  
Disaster Mitigation ◽  
Mitigation Measures ◽  
School Buildings ◽  
Accounting System ◽  
Seismic Evaluation ◽  
Political Factors ◽  
Double Entry

This study examines the factors that influence human vulnerability to natural disasters by focusing on the seismic evaluation of school buildings in Korea. Since natural disasters such as an earthquake often do not take people’s lives directly, but rather indirectly through the destruction of physical structures, seismic reinforcement of school buildings may reduce the vulnerability of their occupants by strengthening structures to withstand such disasters. Disaster mitigation measures are implemented within a state; however, little is known about how they are distributed when the physical properties of structures are taken into account. This paper analyzes a panel data based on the structural properties of school buildings in eight different provinces between 2011 and 2015 using a logistic regression model. The results show that factors identified in cross-country studies, such as economic capacity and political factors, still have influence on earthquake preparedness at the state level, even when the physical properties of structures or technical factors are considered.

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