We examine estimation of the parameters of Susceptible-Infective-Recovered (SIR) models in the context of least squares. We review the use of asymptotic statistical theory and sensitivity analysis to obtain measures of uncertainty for estimates of the model parameters and the basic reproductive number (R0)---an epidemiologically significant parameter grouping. We find that estimates of different parameters, such as the transmission parameter and recovery rate, are correlated, with the magnitude and sign of this correlation depending on the value of R0. Situations are highlighted in which this correlation allows R0 to be estimated with greater ease than its constituent parameters. Implications of correlation for parameter identifiability are discussed. Uncertainty estimates and sensitivity analysis are used to investigate how the frequency at which data is sampled affects the estimation process and how the accuracy and uncertainty of estimates improves as data is collected over the course of an outbreak. We assess the informativeness of individual data points in a given time series to determine when more frequent sampling (if possible) would prove to be most beneficial to the estimation process. This technique can be used to design data sampling schemes in more general contexts.
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http://dx.doi.org/10.3934/mbe.2012.9.553 | DOI Listing |
Environ Sci Technol
January 2025
College of Environmental Science and Engineering, Nankai University, 38 Tongyan Road, Jinnan District, 300350 Tianjin, China.
Reclaimed asphalt pavement (RAP) is a widely used end-of-life (EoL) material in asphalt pavements to increase the material circularity. However, the performance loss due to using RAP in the asphalt binder layer often requires a thicker layer, leading to additional material usage, energy consumption, and transportation effort. In this study, we developed a parametric and probabilistic life cycle assessment (LCA) framework to robustly compare various pavement designs incorporating recycled materials.
View Article and Find Full Text PDFScand J Clin Lab Invest
January 2025
Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
Background: Direct oral anticoagulants (DOACs) can interfere with coagulation analyses, causing erroneous results such as false-positive lupus anticoagulant and false-normal antithrombin, threatening patient safety when overlooked. A test using a prothrombin time quotient method to detect DOAC presence in plasma samples is now commercially available, the MRX PT DOAC, with the result expressed as Clot Time Ratio (CTR).
Objectives: Evaluate the ability of MRX PT DOAC to identify interfering apixaban or rivaroxaban concentrations, identify non-interfering or interfering patient samples, and detect whether a patient is on DOAC treatment.
New Phytol
January 2025
School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA.
The partitioning of photosynthate among various forest carbon pools is a key process regulating long-term carbon sequestration, with allocation to aboveground woody biomass carbon (AGBC) in particular playing an outsized role in the global carbon cycle due to its slow residence time. However, directly estimating the fraction of gross primary productivity (GPP) that goes to AGBC has historically been difficult and time-consuming, leaving us with persistent uncertainties. We used an extensive dataset of tree-ring chronologies co-located at flux towers to assess the coupling between AGBC and GPP, calculate the fraction of fixed carbon that is allocated to AGBC, and understand the drivers of variability in this fraction.
View Article and Find Full Text PDFJ Clin Monit Comput
January 2025
Department of Health Sciences, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam Public Health research institute, Van der Boechorststraat 7, Amsterdam, 1081 BT, the Netherlands.
Purpose: This study provides an economic evaluation of bedside, data-driven, and model-informed precision dosing of antibiotics in comparison with usual care among critically ill patients with sepsis or septic shock.
Methods: This economic evaluation was conducted alongside an AutoKinetics randomized controlled trial. Effect measures included quality-adjusted life years (QALYs), mortality and pharmacokinetic target attainment.
Entropy (Basel)
January 2025
Shandong Rongxin Group Co., Ltd., Zoucheng 273517, China.
In gas-to-methanol processes, optimizing multi-energy systems is a critical challenge toward efficient energy allocation. This paper proposes an entropy-based stochastic optimization method for a multi-energy system in a gas-to-methanol process, aiming to achieve optimal allocation of gas, steam, and electricity to ensure executability under modeling uncertainties. First, mechanistic models are developed for major chemical equipments, including the desulfurization, steam boilers, air separation, and syngas compressors.
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