Using AR and VR characters for enhancing user experience in a museum

Museums and cultural heritage institutions have used technology to create interactive exhibits and pedagogical tools that help spark visitors’ interests. The rise of Augmented, Virtual and Mixed Reality Systems has further enabled the creation of a new generation of immersive experiences that can engage and educate visitors. These technologies can be used to develop digital characters that can serve as virtual tour guides and improve user engagement by answering questions and forming social bonds with the users. While such tour guides have been deployed as exhibits at many museums, the implementation is usually limited to a single exhibit or a section of the museum space. We believe that visitors will be better served if the virtual guide not only enriches the onsite experience but also provides a take-home experience for users to encourage future visits. This thesis explores the enhancement in user experience that such a system can bring by offering onsite and offsite AR and WebVR technologies to create a virtual tour guide that assists visitors at the Genesee Country Village & Museum through interactive dialog as they explore the historic village on the museum campus

Comparison of membrane permeabilities of trace amines and corresponding neurotransmitters

Trace amines (2-phenylethylamine, p-tyramine, p-octopamine and tryptamine) are endogenous compounds structurally similar to the monoamine neurotransmitters and distributed throughout the nervous systems of vertebrates. However, they are not thought to be stored in synaptic vesicles, nor released in an activity-dependent manner. Their synthesis, however, is regulated with the enzyme aromatic L-amino acid decarboxylase being a rate limiting factor. Distinct post-synaptic effects of trace amines have been demonstrated and a family of G-protein-coupled Trace Amine-Associated Receptors (TAAR) has been identified. The TAAR protein, though, is poorly translocated to the cell membrane and remains intracellular. Hence, in order to bind to post-synaptic TAAR, trace amines have to cross cell membranes. This was previously thought to occur by simple diffusion. Recent computer simulations have, however, predicted a high-energy barrier associated with this process. Here the membrane passage of trace amines in the absence of transporters has been measured directly for the first time using the Fluorosome system. The trace amines tyramine (p<0.01), and tryptamine (p<0.001), had significantly greater membrane permeability than the comparable monoamine neurotransmitters, with trace amine permeability half-lives under 15 seconds. The effect of membrane transporters on the permeability of a representative trace amine (tyramine) and neurotransmitter (dopamine) was examined in Caco-2 and synaptosome studies. Tyramine accumulation (≈7-8% of administered concentration) was approximately twice that of dopamine (3-4%) in Caco-2 cells. Equilibration of both tyramine and dopamine occurred in less than 10 minutes. In synaptosomes both tyramine and dopamine uptake equilibrated within 1 minute. Tyramine release from synaptosomes was significantly faster (p<0.001) than that of dopamine. Dopamine release in depolarized membranes was significantly faster (p<0.01, F = 6.95) while tyramine release was significantly slower (p< 0.05, F = 5.86) than in non-depolarized membranes. Release from synaptosomes was significantly slower than Fluorosome membrane passage for both tyramine (p<0.0002, F = 13.63) and dopamine (p<0.0001, F = 56.77) indicating the involvement of processes other than simple diffusion. In conclusion, the trace amines are more permeable than the corresponding neurotransmitters both in the absence and presence of transporters

Mechanistic and metabolic basis of bacterial cross-feeding

In their natural habitat, microorganisms interact with a variety of micro- as well as macroorganisms. Such interactions result in either positive or negative effects on the growth and survival of involved species. Negative effects on growth, can be mostly attributed to competition for limited resources and space, while positive effects on growth are challenging to justify. Metabolite cross-feeding is one such interaction that describes the transfer of primary or secondary metabolites from one organism to another. Considering that metabolites are costly and impose a significant energetic cost to the cell producing them, it is intriguing to know how the process of cross-feeding is favourable. Bacteria employ different mechanisms to carry out the exchange of metabolic by-products, intermediates, and electrons between each other during the process of cross-feeding. Contact-dependent mechanisms of exchange (such as direct cell-cell contact, type secretion systems, and pili), provide the following advantages: (i) protection of the exchanged product from environmental degradation or modification, (ii) provision of the product in a concentrated form, and (iii) prevention of uptake of the product by unintended recipients. The role of contact-dependent mechanisms in the transfer of genetic material (bacterial conjugation) and toxins (contact-dependent inhibition or killing) has been studied for years. However, the importance of similar contact-dependent mechanisms during the cross-feeding of essential nutrients is not fully understood. This thesis aimed at identifying a contact-dependent mechanism for amino acid cross-feeding in bacteria

Mutational meltdown of putative microbial altruists in Streptomyces coelicolor colonies

In colonies of the filamentous multicellular bacterium Streptomyces coelicolor, a subpopulation of cells arises that hyperproduces metabolically costly antibiotics, resulting in a division of labor that increases colony fitness. Because these cells contain large genomic deletions that cause massive reductions to individual fitness, their behavior is similar to altruistic worker castes in social insects or somatic cells in multicellular organisms. To understand these mutant cells’ reproductive and genomic fate after their emergence, we use experimental evolution by serially transferring populations via spore-to-spore transfer for 25 cycles, reflective of the natural mode of bottlenecked transmission for these spore-forming bacteria. We show that in contrast to wild-type cells, putatively altruistic mutant cells continue to decline in fitness during transfer while they lose more fragments from their chromosome ends. In addition, the base-substitution rate in mutants increases roughly 10-fold, possibly due to mutations in genes for DNA replication and repair. Ecological damage, caused by reduced sporulation, coupled with DNA damage due to point mutations and deletions, leads to an inevitable and irreversible type of mutational meltdown in these cells. Taken together, these results suggest the cells arising in the S. coelicolor division of labor are analogous to altruistic reproductively sterile castes of social insects

Generating heterokaryotic cells via bacterial cell-cell fusion

NWOMicrobial Biotechnolog

Exosomal mediated signal transduction through artificial microRNA (amiRNA):A potential target for inhibition of SARS-CoV-2

Exosome trans-membrane signals provide cellular communication between the cells through transport and/or receiving the signal by molecule, change the functional metabolism, and stimulate and/or inhibit receptor signal complexes. COVID19 genetic transformations are varied in different geographic positions, and single nucleotide polymorphic lineages were reported in the second waves due to the fast mutational rate and adaptation. Several vaccines were developed and in treatment practice, but effective control has yet to reach in cent presence. It was initially a narrow immune-modulating protein target. Controlling these diverse viral strains may inhibit their transuding mechanisms primarily to target RNA genes responsible for COVID19 transcription. Exosomal miRNAs are the main sources of transmembrane signals, and trans-located miRNAs can directly target COVID19 mRNA transcription. This review discussed targeted viral transcription by delivering the artificial miRNA (amiRNA) mediated exosomes in the infected cells and significant resources of exosome and their efficacy

Endocytosis-like DNA uptake by cell wall-deficient bacteria

Horizontal gene transfer in bacteria can occur through mechanisms such as conjugation, transduction and transformation, which facilitate the passage of DNA across the cell wall. Here, Kapteijn et al. show that cell wall-deficient bacteria can take up DNA and other extracellular materials via an endocytosis-like process.Horizontal gene transfer in bacteria is widely believed to occur via conjugation, transduction and transformation. These mechanisms facilitate the passage of DNA across the protective cell wall using sophisticated machinery. Here, we report that cell wall-deficient bacteria can engulf DNA and other extracellular material via an endocytosis-like process. Specifically, we show that L-forms of the filamentous actinomycete Kitasatospora viridifaciens can take up plasmid DNA, polysaccharides (dextran) and 150-nm lipid nanoparticles. The process involves invagination of the cytoplasmic membrane, leading to formation of intracellular vesicles that encapsulate extracellular material. DNA uptake is not affected by deletion of genes homologous to comEC and comEA, which are required for natural transformation in other species. However, uptake is inhibited by sodium azide or incubation at 4 degrees C, suggesting the process is energy-dependent. The encapsulated materials are released into the cytoplasm upon degradation of the vesicle membrane. Given that cell wall-deficient bacteria are considered a model for early life forms, our work reveals a possible mechanism for primordial cells to acquire food or genetic material before invention of the bacterial cell wall.Microbial BiotechnologySupramolecular & Biomaterials Chemistr