•Methods of meso scale modelling are discussed with challenges and possible remedies.•Continuum analysis methods and discrete analysis methods are discussed.•Geometry generation, placing algorithms ...and material constitutive laws are discussed.•Applications of mesoscale modelling in fracture and durability are investigated.
Concrete can be considered as a heterogeneous material at mesoscale comprising of several constituents such as aggregates, mortar and Interfacial Transition Zone (ITZ). Mechanical behavior as well as the durability characteristics of concrete is highly dependent on the mesostructure of concrete and investigating the complex phenomena surrounding concrete at mesoscale considering the heterogeneity presents an important tool to understand these complex mechanisms. Presenting the state-of-the-art developments in mesoscale modelling of concrete considering different analysis methods such as continuum Finite Element Modelling (FEM), Lattice Element Method (LEM), Rigid Body Spring Method (RBSM), Discrete Element Method (DEM) and Lattice Discrete Particle Method (LDPM) is the focus of this review paper. Effective methods to generate the geometry of consisting phases in the mesoscale models including different particle shapes and placing algorithms, selecting suitable material constitutive relations for the consisting phases are discussed for these different methods of mesoscale modelling. Potential applications including fracture mechanics and strengths and weaknesses of each technique are highlighted with possible methods to overcome the challenges of mesoscale modelling of concrete.
Purpose
This paper aims to review some effective methods for fully fourth-order nonlinear integral boundary value problems with fractal derivatives.
Design/methodology/approach
Boundary value ...problems arise everywhere in engineering, hence two-scale thermodynamics and fractal calculus have been introduced. Some analytical methods are reviewed, mainly including the variational iteration method, the Ritz method, the homotopy perturbation method, the variational principle and the Taylor series method. An example is given to show the simple solution process and the high accuracy of the solution.
Findings
An elemental and heuristic explanation of fractal calculus is given, and the main solution process and merits of each reviewed method are elucidated. The fractal boundary value problem in a fractal space can be approximately converted into a classical one by the two-scale transform.
Originality/value
This paper can be served as a paradigm for various practical applications.
Objectives:
Multi-analyte assays with algorithmic analyses (MAAAs) use combinations of circulating and clinical markers including omics-based sources for diagnostic and/or prognostic purposes. ...Assessing MAAAs is challenging under existing health technology assessment (HTA) methods or practices. We undertook a scoping review to explore the HTA methods used for MAAAs to identify the criteria used for clinical research and reimbursement purposes.
Methods:
This review included only non-companion (stand-alone) tests that are actionable and that have been evaluated by leading HTA or insurer/reimbursement bodies up to September 2017.
Results:
Twenty-five reports and articles evaluating seventeen MAAAs were examined, most of which have been developed in oncology. The two main models used were the EUnetHTA Core model and the Evaluation of Genomic Applications in Practice and Prevention ACCE framework. Clinical validity and utility criteria were used, as were economic, ethical, legal, and social aspects. Economic evidence on MAAAs was scarce, and there is no consensus on whether the perspectives used are sufficiently broad to include all relevant stakeholders.
Conclusions:
Clinical utility and efficiency were the most used criteria, with stronger evidence needed linking the use of the algorithm with the clinical outcomes in real-life practice. HTA bodies must as well consider questions related to the analytical validity of MAAAs or with organizational aspects. The two main models, the EUnetHTA Core model and the ACCE framework, could be adapted to the assessment of MAAAs.
Aim
To assess the accuracy of guided surgery (mucosa and bone‐supported) compared to mental navigation or the use of a surgical template, in fully edentulous jaws, in a randomized controlled study.
...Material and Methods
Fifty‐nine patients (72 jaws), requiring four to six implants (maxilla or mandible), were consecutively recruited and randomly assigned to one of the following treatment groups; guidance via Materialise Universal®/mucosa, Materialise Universal®/bone, Facilitate™/mucosa, Facilitate™/bone, or mental navigation or a pilot‐drill template. The precision was assessed by matching the planning computed tomography (CT) with a post‐operative cone beam CT.
Results
A significant lower mean deviation at the entry point (1.4 mm, range: 0.3–3.7), at the apex (1.6 mm, range: 0.2–3.7) and angular deviation (3.0°, range: 0.2–16°) was observed for the guiding systems when compared to mental navigation (2.7 mm, range: 0.3–8.3; 2.9 mm, range: 0.5–7.4 and 9.9°, range: 1.5–27.8) and to the surgical template group (3.0 mm, range: 0.6–6.6; 3.4 mm, range: 0.3–7.5 and 8.4°, range: 0.6–21.3°). Differences between bone and mucosa support or type of guidance were negligible. Jaw and implant location (posterior–anterior, left–right), however, had a significant influence on the accuracy when guided.
Conclusion
Based on these findings, guided implant placement appears to offer clear accuracy benefits.
A new 3-D domain decomposition based hybrid finite-difference time-domain (FDTD)/finite-element time-domain (FETD) method is introduced to facilitate electromagnetic modeling by exploiting both the ...computational efficiency of FDTD and the meshing flexibility of FETD. The proposed hybrid method allows the FETD mesh and the FDTD grid to be nonconformal based on domain decomposition technique. It implements the hybridization with a buffer zone, which functions as a transition region between FDTD and FETD. The buffer zone helps the proposed hybrid method obviate the interpolation approach for field coupling of the nonconformal mesh and hence overcome the late-time instability issue. The discontinuous Galerkin method is utilized to couple different regions, thus improving the coupling accuracy compared with that using the Dirichlet boundary condition. Moreover, the hybrid method allows further division of the FETD region into multiple subdomains when the degrees of freedom in this region are large. For temporal discretization, a global leapfrog time integration scheme is implemented to sequentially update the fields in the FDTD, buffer, and FETD regions. The numerical results are shown to demonstrate the meshing flexibility and computational efficiency of the proposed hybrid method inherited from FETD and FDTD methods.
Compared to RNA-sequencing transcript differential analysis, gene-level differential expression analysis is more robust and experimentally actionable. However, the use of gene counts for statistical ...analysis can mask transcript-level dynamics. We demonstrate that 'analysis first, aggregation second,' where the p values derived from transcript analysis are aggregated to obtain gene-level results, increase sensitivity and accuracy. The method we propose can also be applied to transcript compatibility counts obtained from pseudoalignment of reads, which circumvents the need for quantification and is fast, accurate, and model-free. The method generalizes to various levels of biology and we showcase an application to gene ontologies.
•A new iteration regularization algorithm is proposed.•The proposed iteration regularization algorithm is strictly proved.•The present method is powerful for load identification for stochastic ...structure.•The newly developed method saves computational cost remarkably compared with MCS.•Numerical simulations validate the obtained theoretical results.
In this paper, we propose a novel fast convergence iterative regularization method on the basis of a new iterative regularization operator to solve the dynamic load identification of stochastic structures. Firstly, the validity and convergence of the proposed algorithm is proved by strict mathematical theory and numerical results of engineering example. Secondly, the dynamic load identification of uncertain structures can be transformed into a series of deterministic inverse problems by the matrix perturbation method. Finally, we also assess the statistical characteristics of identified loads using the statistical theory. Particularly, the proposed method successfully solves the dynamic load identification of stochastic structure. Numerical simulations are given to validate the feasibility of the presented method in this paper.
The NIH-funded National Research Mentoring Network (NRMN) aims to increase the representation and success of underrepresented groups (URGs) in biomedical research by enhancing the training and career ...development of individuals from diverse backgrounds, communities, and cultures. The national scope of NRMN, its wide array of innovative programs in mentor and mentee matching and training across the career spectrum, requires a collaborative evaluation strategy that addresses both internal and external evaluation needs. Due to the variety of programs implemented for each target group, the NRMN program is responsible for its own process and short-term outcome evaluations and the national Coordination and Evaluation Center (CEC) is responsible for assessing the medium and long-term effectiveness of the implemented strategies and program sustainability. Using a collaborative, utilization-focused evaluation framework, both internal NRMN evaluators and the CEC are working to translate findings into information that can be used to make both short term and long-term decisions about the efficacy and reach of the NRMN model. This important information can then inform efforts to institutionalize the current programs and potentially replicate them elsewhere.
The overall evaluation of NRMN is guided by both outcome and process questions that are tailored for each target group. The different target groups include faculty and others who serve as mentors, mentees across academic training and career stages, and researchers without a history of independently funded research. NRMN is also building the capacity for training those pursuing biomedical careers by developing "master trainers" for both mentoring and grantsmanship programs in organizations and institutions that can support expanded training efforts aimed at diversifying the biomedical workforce.
Results of this evaluation will be used to inform the design and implementation of sustainable, effective, and comprehensive mentoring and career development initiatives that promote diversity in the biomedical research workforce. Our collaborative evaluation design, theoretically-derived measurement instruments, efficient data systems, and timely reporting serve as an example of how to put evaluation principles described into practice for large, multi-site, and multi-dimensional research training programs like NRMN.
Summary
This paper presents a hybrid element‐free Galerkin (HEFG) method for solving wave propagation problems. By introducing the dimension split method, the three‐dimensional wave propagation ...problems are transformed into a series of two‐dimensional ones in other one‐dimensional directions. The two‐dimensional problems are solved using the improved element‐free Galerkin (IEFG) method, and the finite difference method is used in the one‐dimensional splitting direction and the time space. Then, the formulas of the HEFG method for three‐dimensional wave propagation problems are obtained. Numerical examples are selected to show the effectiveness and the advantage of the HEFG method. The convergence and error analysis of the HEFG method are discussed according to the numerical results under different splitting directions, weight functions, node distributions, scale parameters of the influence domain, penalty factors, and time steps. The numerical results are given to show the convergence and advantages of the HEFG method over the IEFG method. Comparing with the IEFG method, the HEFG method has greater computational precision and speed for three‐dimensional wave propagation problems.
In the last 10 years, the barriers preventing the uptake of foreign DNA by clinical
isolates have been identified and powerful mutagenesis techniques such as allelic exchange are now possible in most ...genotypes. However, these targeted approaches can still be cumbersome, and the construction of unmarked deletions/point mutations may take many weeks or months. Here, we introduce a streamlined allelic exchange protocol using IMxxB
and the plasmid pIMAY-Z. With this optimized approach, a site-specific mutation can be introduced into
in 5 days, from the start of cloning to isolation of genomic DNA for confirmatory whole-genome sequencing. This streamlined protocol considerably reduces the time required to introduce a specific, unmarked mutation in
and should dramatically improve the scalability of gene-function studies.
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