Overview Of Available Models Research Articles

Pluripotent stem cell assays: Modalities and applications for predictive developmental toxicity

This manuscript provides a review focused on embryonic stem cell-based models and their place within the landscape of alternative developmental toxicity assays. Against the background of the principles of developmental toxicology, the wide diversity of alternative methods using pluripotent stem cells developed in this area over the past half century is reviewed. In order to provide an overview of available models, a systematic scoping review was conducted following a published protocol with inclusion criteria, which were applied to select the assays. Critical aspects including biological domain, readout endpoint, availability of standardized protocols, chemical domain, reproducibility and predictive power of each assay are described in detail, in order to review the applicability and limitations of the platform in general and progress moving forward to implementation. The horizon of innovative routes of promoting regulatory implementation of alternative methods is scanned, and recommendations for further work are given.

Current Evidence for Simulation-Based Training and Assessment of Myringotomy and Ventilation Tube Insertion: A Systematic Review.

Myringotomy and ventilation tube insertion (MT) is a key procedure in otorhinolaryngology and can be trained using simulation models. We aimed to systematically review the literature on models for simulation-based training and assessment of MT and supporting educational evidence. PubMed, Embase, Cochrane Library, Web of Science, Directory of Open Access Journals. Inclusion criteria were MT training and/or skills assessment using all types of training modalities and learners. Studies were divided into 1) descriptive and 2) educational interventional/observational in the analysis. For descriptive studies, we provide an overview of available models including materials and cost. Educational studies were appraised using Kirkpatrick's level of educational outcomes, Messick's framework of validity, and a structured quality assessment tool. Forty-six studies were included consisting of 21 descriptive studies and 25 educational studies. Thirty-one unique physical and three virtual reality simulation models were identified. The studies report moderate to high realism of the different simulators and trainees and educators perceive them beneficial in training MT skills. Overall, simulation-based training is found to reduce procedure time and errors, and increase performance as measured using different assessment tools. None of the studies used a contemporary validity framework and the current educational evidence is limited. Numerous simulation models and assessment tools have been described in the literature but educational evidence and systematic implementation into training curricula is scarce. There is especially a need to establish the effect of simulation-based training of MT in transfer to the operating room and on patient outcomes.

A review on numerical modelling of flashing flow with application to nuclear safety analysis

The flashing flow is a relevant multiphase phenomenon in many technical applications including nuclear safety analysis, which has been the subject of intense research for several decades. Numerical studies have evolved from one-dimensional to multi-dimensional. A variety of methods has been proposed, while a broad consensus does not exist yet. The present work aims to present an overview of available models and assess their limitations and perspectives by conducting an extensive literature survey. The final focus was put on recent progresses of computational fluid dynamics simulations. Some consensus on modelling interfacial slip, phase change mechanism and bubble size is identified. Since flashing scenarios often accompanying with high void fraction and broad bubble size range, a poly-disperse two-fluid model is recommended. Thermal phase change model is superior to pressure phase change, relaxation and equilibrium models for practical flashing problems, however incorporation of pressure effects is desirable. Major challenges comprise improving closure models for interphase transfer, bubble dynamics processes, interfacial area as well two-phase turbulence. For this purpose, high-resolution high quality experimental data are important, which are lacking in many cases. Considering that heterogeneous gas structures often exist in flashing flows, multi-field approaches able to handle different shapes of gas-liquid interface and including the shape effect in closure models are recommended for further study.

Calcium based sorbent calcination and sintering reaction models overview

Several models considering the pulverized sorbent reactions with pollutant gases were developed over the past years. In this paper, we present a detailed overview of available models for direct furnace injection of pulverized calcium sorbent suitable for potential application in CFD codes, with respect to implementation difficulty and computational resources demand. Depending on the model, variations in result accuracy, data output, and computational power required may occur. Some authors separate the model of calcination reaction, combined with the sintering model, and afterwards model the sulfation. Other authors assume the calcination to be instantaneous, and focus the modelling efforts toward the sulfation reaction, adding the sintering effects as a parameter in the efficiency coefficient. Simple models quantify the reaction effects, while more complex models attempt to describe and explain internal particle reactions through different approaches to modelling of the particle internal structure.

An overview of available crop growth and yield models for studies and assessments in agriculture.

The scientific community offers numerous crop models with different levels of sophistication. In such a wide range of crop models, users should have the possibility to choose the most suitable, in terms of detail, scale and representativeness, to their objectives. However, even when an appropriate choice is made, model limitations should be clarified such that modelling studies are put in the proper perspective and robust applications are achieved. This work is an overview of available models to simulate crop growth and yield. A summary matrix with more than 70 crop models is provided, storing the main model characteristics that can help users to choose the proper tool according to their purposes. Overall, we found that two main aspects of models, despite their importance, are not always clear from the published references, i.e. the versatility of the models, in terms of reliable transferability to different conditions, and the degree of complexity. Hence, the developers of models should be encouraged to pay more attention to clarifying the model limitations and limits of applicability, and users should make an effort in proper model selection, to save time often devoted to iteration of tuning steps to force an inappropriate model to be adapted to their own purpose.

Animal Models forFrancisella tularensisandBurkholderiaSpecies

The development and regulatory approval of medical countermeasures (MCMs) for the treatment and prevention of bacterial threat agent infections will require the evaluation of products in animal models. To obtain regulatory approval, these models must accurately recapitulate aspects of human disease, including, but not necessarily limited to, route of exposure, time to disease onset, pathology, immune response, and mortality. This article focuses on the state of animal model development for 3 agents for which models are largely immature: Francisella tularensis, Burkholderia mallei, and Burkholderia pseudomallei. An overview of available models and a description of scientific and regulatory gaps are provided.

State‐of‐the‐art management models for lakes and reservoirs

AbstractThis paper reviews current models that can be used in lake management, mainly for eutrophication and wetland areas. The latter type of model, in particular, has developed rapidly during the past decade due to the increasing importance of wetlands as traps for nutrients originating from non‐point sources. The experience gained in lake modelling since the mid‐1980s can be summarized as follows: (i) 3‐D hydrodynamic models are available today but are not necessarily the right answer to a given modelling problem (dependent on data availability); (ii) models with a wide spectrum of complexities are available which make it possible to select a type of model appropriate to available data; and (iii) several models with general applicability are available, yet it is necessary to tailor a model for each individual case (generally based on experience from previous model studies). The experience gained by the use of the so‐called Glumsø model on 25 case studies led to the same conclusion: modifications are needed in the original model for each new case study to allow for the specific characteristics of the lake modelled. Lake management models have been developed for eutrophication, oxygen depletion, various specific pollution problems, thermocline formation, acidification, and the use of wetlands to cope with non‐point pollution, particularly for removal of nitrogen by denitrification. An overview of available models, including their shortcomings, is given in the text. We have experience in using models for many different environmental problems of lakes, but it is necessary to improve these models by including more ecological components. These improvements are discussed in relation to the most recent experiences in the use of models with dynamic structures.