The 21st Annual Meeting of the Rocky Mountain Virology Association

Nestled within the Rocky Mountain National Forest, 114 scientists and students gathered at Colorado State University’s Mountain Campus for this year’s 21st annual Rocky Mountain National Virology Association meeting. This 3-day retreat consisted of 31 talks and 30 poster presentations discussing advances in research pertaining to viral and prion diseases. The keynote address provided a timely discussion on zoonotic coronaviruses, lessons learned, and the path forward towards predicting, preparing, and preventing future viral disease outbreaks. Other invited speakers discussed advances in SARS-CoV-2 surveillance, molecular interactions involved in flavivirus genome assembly, evaluation of ethnomedicines for their efficacy against infectious diseases, multi-omic analyses to define risk factors associated with long COVID, the role that interferon lambda plays in control of viral pathogenesis, cell-fusion-dependent pathogenesis of varicella zoster virus, and advances in the development of a vaccine platform against prion diseases. On behalf of the Rocky Mountain Virology Association, this report summarizes select presentations.

Accurate long-read de novo assembly evaluation with Inspector

Long-read de novo genome assembly continues to advance rapidly. However, there is a lack of effective tools to accurately evaluate the assembly results, especially for structural errors. We present Inspector, a reference-free long-read de novo assembly evaluator which faithfully reports types of errors and their precise locations. Notably, Inspector can correct the assembly errors based on consensus sequences derived from raw reads covering erroneous regions. Based on in silico and long-read assembly results from multiple long-read data and assemblers, we demonstrate that in addition to providing generic metrics, Inspector can accurately identify both large-scale and small-scale assembly errors.

Pengembangan media pembelajaran interaktif berbasis flash dengan pendekatan kontekstual pada materi jarak, waktu, dan kecepatan untuk siswa SD kelas V semester I

Peningkatan kualitas pendidikan dapat dicapai dengan menciptakan terobosan dalam bidang pembelajaran, salah satunya adalah dengan menciptakan media pembelajaran. Tujuan dari penelitian ini adalah menghasilkan media pembelajaran interaktif dengan pendekatan kontekstual untuk siswa SD pada pokok bahasan jarak, waktu, dan kecepatan. Pengembangan media pembelajaran interaktif ini mengadaptasi model pengembangan Luther (Sutopo, 2003) dan Purwanto (2004), yaitu model CADMAETR (Concept, Analysis, Design, Material collecting, Assembly, Evaluation, Testing, and Revition). Uji coba yang dilaksanakan adalah uji kevalidan dilakukan oleh satu orang dosen dan dua orang guru matematika, sedangkan uji kepraktisan dan uji keefektifan dilakukan oleh 6 orang siswa sebagai subjek uji coba. Berdasarkan analisis pengembangan didapatkan hasil bahwa media pembelajaran yang dikembangkan dinyatakan valid, praktis, dan efektif.

Significantly improving the quality of genome assemblies through curation

Genome sequence assemblies provide the basis for our understanding of biology. Generating error-free assemblies is therefore the ultimate, but sadly still unachieved goal of a multitude of research projects. Despite the ever-advancing improvements in data generation, assembly algorithms and pipelines, no automated approach has so far reliably generated near error-free genome assemblies for eukaryotes. Whilst working towards improved datasets and fully automated pipelines, assembly evaluation and curation is actively used to bridge this shortcoming and significantly reduce the number of assembly errors. In addition to this increase in product value, the insights gained from assembly curation are fed back into the automated assembly strategy and contribute to notable improvements in genome assembly quality. We describe our tried and tested approach for assembly curation using gEVAL, the genome evaluation browser. We outline the procedures applied to genome curation using gEVAL and also our recommendations for assembly curation in a gEVAL-independent context to facilitate the uptake of genome curation in the wider community.

A Roadmap to Sequence Assembly Evaluation Tools

: The assembly evaluation process is the starting step towards meaningful downstream data analysis. We need to know how much accurate information is included in an assembled sequence before going further to any data analysis stage. Four basic metrics are targeted by different assembly evaluation tools: contiguity, accuracy, completeness, and contamination. Some tools evaluate these metrics based on comparing the assembly results to a closely related reference. Others utilize different types of heuristics to overcome the missing of a guiding reference, such as the consistency between assembly results and sequencing reads. In this paper, we discuss the assembly evaluation process as a core stage in any sequence assembly pipeline and present a roadmap that is followed by most assembly evaluation tools to assess different metrics. We highlight the challenges that currently exist in the assembly evaluation tools and summarize their technical and practical details to help the end-users choose the best tool according to their working scenarios. To address the similarities/differences among different assembly assessment tools, including their evaluation approaches, metrics, comprehensive nature, limitations, usability and how the evaluated results are presented to the end-user, we provide a practical example for evaluating Velvet assembly results for S. aureus dataset from GAGE competition. A Github repository (https://github.com/SaraEl-Metwally/Assembly-Evaluation-Tools) is created for evaluation result details along with their generated command line parameters.

Merqury: reference-free quality, completeness, and phasing assessment for genome assemblies

Recent long-read assemblies often exceed the quality and completeness of available reference genomes, making validation challenging. Here we present Merqury, a novel tool for reference-free assembly evaluation based on efficient k-mer set operations. By comparing k-mers in a de novo assembly to those found in unassembled high-accuracy reads, Merqury estimates base-level accuracy and completeness. For trios, Merqury can also evaluate haplotype-specific accuracy, completeness, phase block continuity, and switch errors. Multiple visualizations, such as k-mer spectrum plots, can be generated for evaluation. We demonstrate on both human and plant genomes that Merqury is a fast and robust method for assembly validation.

Significantly improving the quality of genome assemblies through curation

BackgroundGenome sequence assemblies provide the basis for our understanding of biology. Generating error-free assemblies is therefore the ultimate, but sadly still unachieved goal of a multitude of research projects. Despite the ever-advancing improvements in data generation, assembly algorithms and pipelines, no automated approach has so far reliably generated near error-free genome assemblies for eukaryotes.ResultsWhilst working towards improved data sets and fully automated pipelines, assembly evaluation and curation is actively employed to bridge this shortcoming and significantly reduce the number of assembly errors. In addition to this increase in product value, the insights gained from assembly curation are fed back into the automated assembly strategy and contribute to notable improvements in genome assembly quality.ConclusionsWe describe our tried and tested approach for assembly curation using gEVAL, the genome evaluation browser. We outline the procedures applied to genome curation using gEVAL and also our recommendations for assembly curation in an gEVAL-independent context to facilitate the uptake of genome curation in the wider community.

PDR: a new genome assembly evaluation metric based on genetics concerns

Motivation Existing genome assembly evaluation metrics provide only limited insight on specific aspects of genome assembly quality, and sometimes even disagree with each other. For better integrative comparison between assemblies, we propose, here, a new genome assembly evaluation metric, Pairwise Distance Reconstruction (PDR). It derives from a common concern in genetic studies, and takes completeness, contiguity, and correctness into consideration. We also propose an approximation implementation to accelerate PDR computation. Results Our results on publicly available datasets affirm PDR’s ability to integratively assess the quality of a genome assembly. In fact, this is guaranteed by its definition. The results also indicated the error introduced by approximation is extremely small and thus negligible. Availabilityand implementation https://github.com/XLuyu/PDR. Supplementary information Supplementary data are available at Bioinformatics online.

Assessment the Quality of Genome Assemblies by using QUAST Tool for Metagenomics

Number of assembly algorithms have emerged out but due to constraints of genome sequencing techniques no one is perfect. Various methods for assembler’s comparison have been developed, but none is yet a recognized standard. The problem of evaluating assemblies of formerly unsequenced species has not been considered, because mostly existing methods for comparing assemblies are only applicable to new assemblies of finished genomes. For comparing and evaluating genome assemblies we have used QUAST (Quality Assessment Tool). This tool is used to assess the quality of leading assembly software by evaluating quality metrics. Assemblies with a reference genome, as well as without a reference can be evaluated by QUAST tool. For genome assembly evaluation based on alignment of contigs to a reference, it is a modern tool. In this study we demonstrate QUAST performance by comparing several leading genome assemblers on three metagenomic datasets.