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Biology subjects

Dums, J. T.

Publications and source records attributed to Dums, J. T..

3 recordsLinked to original sources

Student experiences with an interactive 3D immersive biotechnology simulation and its impact on motivational beliefs

The development and use of virtual laboratories to augment traditional in-person skills training continues to grow. Virtual labs have been implemented in a number of diverse educational settings, which have many purported benefits including their adaptability, accessibility, and repeatability. However, few studies have evaluated the impact of virtual laboratories outside of academic achievement and skills competencies, especially in biotechnology. In this study, an interdisciplinary team of content experts, video game researchers, instructional designers, and assessment experts developed a 3D immersive simulation designed to teach novice scientists the technical skills necessary to perform sterile mammalian cell culture technique. Unique to the simulation development process is the recreation of an immersive experience through the capture of details in the real-world lab where participants have the freedom of choice in their actions, while receiving immediate feedback on their technical skills as well as procedural execution. However, unlike an in-person laboratory course, students are able to iterate and practice their skills outside of class time and learn from their mistakes. Using a mixed-methods study design, over the course of two semesters we evaluated student attitudes of the simulation and their science motivational beliefs including self-efficacy and science identity after engaging with the simulation prior to the physical laboratory. Our results show that students science identity remained unchanged while their science self-efficacy increased. Furthermore, students had positive perceptions of the benefits of the virtual simulation. These data suggest that the virtual cell culture simulation can be a useful pedagogical training tool to bolster students motivational beliefs that is both accessible and easy to implement.

scientific communication and education↗

B12-dependent virioplankton demonstrate interseasonal dynamics and associate with a diversity of pelagic bacterioplankton

Through infection and lysis of their coexisting bacterial hosts, viruses impact the biogeochemical cycles sustaining globally significant pelagic oceanic ecosystems. Currently, little is known of the ecological interactions between lytic viruses and their bacterial hosts underlying these biogeochemical impacts at ecosystem scales. This study focused on populations of lytic viruses carrying the B12- dependent Class II monomeric ribonucleotide reductase (RNR) gene, ribonucleotide triphosphate reductase (RTPR), documenting seasonal changes in pelagic virioplankton and bacterioplankton using amplicon sequences of RTPR and the 16S rRNA gene, respectively. Amplicon sequence libraries were analyzed using compositional data analysis tools that account for the compositional nature of these data. Both virio- and bacterioplankton communities responded to environmental changes typically seen across seasonal cycles as well as shorter term upwelling-downwelling events. Defining RTPR-carrying viral populations according to major phylogenetic clades proved a more robust means of exploring virioplankton ecology than operational taxonomic units defined by percent sequence homology. Virioplankton RTPR populations showed positive associations with a broad phylogenetic diversity of bacterioplankton including dominant taxa within pelagic oceanic ecosystems such as Prochlorococcus and SAR11. Temporal changes in RTPR-virioplankton, occurring as both free viruses and within infected cells, indicated possible viral-host pairs undergoing sustained infection and lysis cycles throughout the seasonal study. Phylogenetic relationships inferred from RTPR sequences mirrored ecological patterns in virio- and bacterioplankton populations demonstrating possible genome to phenome associations for an essential viral replication gene.

ecology↗

Spontaneously produced lysogenic phages are an important component of the soybean Bradyrhizobium mobilome

The ability to nodulate and fix atmospheric nitrogen in soybean root nodules makes soybean Bradyrhizobium spp. (SB) critical in supplying humanitys nutritional needs. The intricacies of SB-plant interactions have been studied extensively; however, bradyrhizobial ecology as influenced by phages has received somewhat less attention even though these interactions may significantly impact soybean yield. In batch culture four SB strains, S06B (B. japonicum, S06B-Bj), S10J (B. japonicum, S10J-Bj), USDA 122 (B. diazoefficiens, USDA 122-Bd), and USDA 76T (B. elkanii, USDA 76-Be), spontaneously (without apparent exogenous chemical or physical induction) produced phages throughout the growth cycle; for three strains, phage concentrations exceeded cell numbers by ca. 3-fold after 48 h incubation. Observed spontaneously produced phages (SPP) were tailed. Phage terminase large-subunit protein phylogeny revealed possible differences in phage packaging and replication mechanisms. Bioinformatic analyses predicted multiple prophage regions within each SB genome preventing accurate identification of SPP genomes. A DNA sequencing approach was developed that accurately delineated the boundaries of four SPP genomes within three of the SB chromosomes. Read mapping suggested that the SPP are capable of transduction. In addition to the phages, bacterial strains S06B-Bj and USDA 76-Be were rich in mobile elements consisting of insertion sequences (IS) and large, conjugable, broad host range plasmids. The prevalence of SPP along with IS and plasmids indicate that horizontal gene transfer likely plays an outsized role in SB ecology and may subsequently impact soybean productivity. ImportancePrevious studies have shown that IS and plasmids mediate horizontal gene transfer (HGT) of symbiotic nodulation (nod) genes in SB; however, these events require close cell to cell contact which could be limited in soil environments. Bacteriophage assisted gene transduction through spontaneously produced prophages could provide stable means of HGT not limited by the constraints of proximal cell to cell contact. Phage mediated HGT events could be important in SB population ecology with concomitant impacts on soybean agriculture.

microbiology↗