Uncertainty Assessment of Soil Erosion Model Using Particle Filtering

Recent advances in computer with geographic information system(GIS) technologies have allowed modelers to develop physics-based models for modeling soil erosion processes in time and space.However, it has been widely recognized that the effect of uncertainties on model predictions may be more significant when modelers apply such models for their own modeling purposes.Sources of uncertainty involved in modeling include data, model structural, and parameter uncertainty.To deal with the uncertain parameters of a catchment-scale soil erosion model(CSEM) and assess simulation uncertainties in soil erosion, particle filtering modeling(PF) is introduced in the CSEM.The proposed method, CSEM-PF, estimates parameters of non-linear and non-Gaussian systems, such as a physics-based soil erosion model by assimilating observation data such as discharge and sediment discharge sequences at outlets.PF provides timevarying feasible parameter sets as well as uncertainty bounds of outputs while traditional automatic calibration techniques result in a time-invariant global optimal parameter set.CSEM-PF was applied to a small mountainous catchment of the Yongdamdam in Korea for soil erosion modeling and uncertainty assessment for three historical typhoon events.Finally, the most optimal parameter sets and uncertainty bounds of simulation of both discharge and sediment discharge at each time step of the study events are provided.

MCMV-based vaccine vectors expressing full-length viral proteins provide long-term humoral immune protection upon a single-shot vaccination

Global pandemics caused by influenza or coronaviruses cause severe disruptions to public health and lead to high morbidity and mortality.There remains a medical need for vaccines against these pathogens.CMV(cytomegalovirus)is aβ-herpesvirus that induces uniquely robust immune responses in which remarkably large populations of antigen-specific CD8+T cells are maintained for a lifetime.Hence,CMV has been proposed and investigated as a novel vaccine vector for expressing antigenic peptides or proteins to elicit protective cellular immune responses against numerous pathogens.We generated two recombinant murine CMV(MCMV)vaccine vectors expressing hemagglutinin(HA)of influenza A virus(MCMV^(HA))or the spike protein of severe acute respiratory syndrome coronavirus 2(MCMV^(S)).A single injection of MCMVs expressing either viral protein induced potent neutralizing antibody responses,which strengthened over time.Importantly,MCMV^(HA)-vaccinated mice were protected from illness following challenge with the influenza virus,and we excluded that this protection was due to the effects of memory T cells.Conclusively,we show here that MCMV vectors induce not only long-term cellular immunity but also humoral responses that provide long-term immune protection against clinically relevant respiratory pathogens.