Uber

Uber focuses primarily on the ride-hailing industry, which puts the company in direct competition with regular taxis. The company is like a lot of tech-driven, fast growing entrepreneurial firms in that it still struggles for profitability. Also, the popularity of this new form of transportation has put the company and its close competitors, such as Lyft, in the spotlight of government lawmakers and regulators. If they classify Uber drivers as employees rather than independent contractors, it could dramatically alter the Uber business model. This case is written in the aftermath of the ouster of one of the company’s co-founders as CEO, a not-so-successful initial public offering (IPO), and some very serious human resources issues associated with widely publicized instances of sexual harassment and mistreatment of drivers

Transparent Furnace for Observing Electrochemical Separation of Used Nuclear Fuel

Electrochemical separation of used nuclear fuel (UNF) operating at 500°C is confined within a furnace, making it difficult for a visual observation. Thus, flow characteristic predictions from the furnace are often calculated through advanced computational modeling methods. Therefore, it is necessary to develop an innovative idea, combining mechanical and chemical skill sets to design and build a transparent furnace that provides a clear visualization that can later be coupled with an optical flow-visualization method, such as Laser Doppler Anemometry (LDA). Deliverables of the project include the complete design and illustration of the prototype operating up to 500°C. Challenges of the project include available resources, limited budget and time, preventing further experimentations with a large variety of chemicals and prototype construction materials. The team began the project by researching materials and designing the prototype using CAD software. Once the experimental setup was designed, the team allocated and purchased resources, performed necessary machining, and assembled the prototype. The chemicals and prototype were then tested in the lab at high temperatures to provide a proof of concept. Finally, electrochemical experiments were performed using a ternary AgCl-LiCl-KCl salt system (0.5:44.0:55.5 wt%), resulting in a successful silver deposition on the cathode. Remaining issues include: (1) complete purging of the system to produce entirely transparent liquid chemicals in which to observe the electrochemical separation, (2) complete melting of the outer chemical bath with submersible heater and temperature controller to provide consistent, continual heating of the inner vessel, and (3) revisiting insulation challenges to prevent the inner and outer system from cooling while remaining transparent continuously. This project provides a preliminary understanding of the fundamental electrorefining model and reprocessing and recycling of UNF.https://scholarscompass.vcu.edu/capstone/1136/thumbnail.jp

Functional genomics and microbiome profiling of the Asian longhorned beetle (\u3ci\u3eAnoplophora glabripennis\u3c/i\u3e) reveal insights into the digestive physiology and nutritional ecology of wood feeding beetles

Background: Wood-feeding beetles harbor an ecologically rich and taxonomically diverse assemblage of gut microbes that appear to promote survival in woody tissue, which is devoid of nitrogen and essential nutrients. Nevertheless, the contributions of these apparent symbionts to digestive physiology and nutritional ecology remain uncharacterized in most beetle lineages. Results: Through parallel transcriptome profiling of beetle- and microbial- derived mRNAs, we demonstrate that the midgut microbiome of the Asian longhorned beetle (Anoplophora glabripennis), a member of the beetle family Cerambycidae, is enriched in biosynthetic pathways for the synthesis of essential amino acids, vitamins, and sterols. Consequently, the midgut microbiome of A. glabripennis can provide essential nutrients that the beetle cannot obtain from its woody diet or synthesize itself. The beetle gut microbiota also produce their own suite of transcripts that can enhance lignin degradation, degrade hemicellulose, and ferment xylose and wood sugars. An abundance of cellulases from several glycoside hydrolase families are expressed endogenously by A. glabripennis, as well as transcripts that allow the beetle to convert microbe-synthesized essential amino acids into non-essential amino acids. A. glabripennis and its gut microbes likely collaborate to digest carbohydrates and convert released sugars and amino acid intermediates into essential nutrients otherwise lacking from their woody host plants. Conclusions: The nutritional provisioning capabilities of the A. glabripennis gut microbiome may contribute to the beetles’ unusually broad host range. The presence of some of the same microbes in the guts of other Cerambycidae and other wood-feeding beetles suggests that partnerships with microbes may be a facilitator of evolutionary radiations in beetles, as in certain other groups of insects, allowing access to novel food sources through enhanced nutritional provisioning

Structure-guided evolution of antigenically distinct adeno-associated virus variants for immune evasion

Preexisting neutralizing antibodies (NAbs) against adeno-associated viruses (AAVs) pose a major, unresolved challenge that restricts patient enrollment in gene therapy clinical trials using recombinant AAV vectors. To tackle this problem, we developed a structure-guided approach to evolve AAV variants with altered antigenic footprints that cannot be recognized by preexisting antibodies. These proof-of-principle studies demonstrate that synthetic AAV variants can be evolved to evade neutralizing sera from different species—mice, nonhuman primates, and humans—without compromising yield and transduction efficiency or altering tropism. Our approach provides a roadmap for engineering any AAV strain to evade NAbs in prospective patients for human gene therapy

Genome of the Asian Longhorned Beetle (\u3cem\u3eAnoplophora glabripennis\u3c/em\u3e), a Globally Significant Invasive Species, Reveals Key Functional and Evolutionary Innovations at the Beetle-Plant Interface

Background: Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle. Results: The Asian longhorned beetle genome encodes a uniquely diverse arsenal of enzymes that can degrade the main polysaccharide networks in plant cell walls, detoxify plant allelochemicals, and otherwise facilitate feeding on woody plants. It has the metabolic plasticity needed to feed on diverse plant species, contributing to its highly invasive nature. Large expansions of chemosensory genes involved in the reception of pheromones and plant kairomones are consistent with the complexity of chemical cues it uses to find host plants and mates. Conclusions: Amplification and functional divergence of genes associated with specialized feeding on plants, including genes originally obtained via horizontal gene transfer from fungi and bacteria, contributed to the addition, expansion, and enhancement of the metabolic repertoire of the Asian longhorned beetle, certain other phytophagous beetles, and to a lesser degree, other phytophagous insects. Our results thus begin to establish a genomic basis for the evolutionary success of beetles on plants

Genome of the Asian longhorned beetle (Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetle–plant interface

Background Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle. Results The Asian longhorned beetle genome encodes a uniquely diverse arsenal of enzymes that can degrade the main polysaccharide networks in plant cell walls, detoxify plant allelochemicals, and otherwise facilitate feeding on woody plants. It has the metabolic plasticity needed to feed on diverse plant species, contributing to its highly invasive nature. Large expansions of chemosensory genes involved in the reception of pheromones and plant kairomones are consistent with the complexity of chemical cues it uses to find host plants and mates. Conclusions Amplification and functional divergence of genes associated with specialized feeding on plants, including genes originally obtained via horizontal gene transfer from fungi and bacteria, contributed to the addition, expansion, and enhancement of the metabolic repertoire of the Asian longhorned beetle, certain other phytophagous beetles, and to a lesser degree, other phytophagous insects. Our results thus begin to establish a genomic basis for the evolutionary success of beetles on plants

Genome of the Asian longhorned beetle (Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetle-plant interface

Background: Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle. Results: The Asian longhorned beetle genome encodes a uniquely diverse arsenal of enzymes that can degrade the main polysaccharide networks in plant cell walls, detoxify plant allelochemicals, and otherwise facilitate feeding on woody plants. It has the metabolic plasticity needed to feed on diverse plant species, contributing to its highly invasive nature. Large expansions of chemosensory genes involved in the reception of pheromones and plant kairomones are consistent with the complexity of chemical cues it uses to find host plants and mates. Conclusions: Amplification and functional divergence of genes associated with specialized feeding on plants, including genes originally obtained via horizontal gene transfer from fungi and bacteria, contributed to the addition, expansion, and enhancement of the metabolic repertoire of the Asian longhorned beetle, certain other phytophagous beetles, and to a lesser degree, other phytophagous insects. Our results thus begin to establish a genomic basis for the evolutionary success of beetles on plants

Functional genomics and microbiome profiling of the Asian longhorned beetle (Anoplophora glabripennis) reveal insights into the digestive physiology and nutritional ecology of wood feeding beetles

Background: Wood-feeding beetles harbor an ecologically rich and taxonomically diverse assemblage of gut microbes that appear to promote survival in woody tissue, which is devoid of nitrogen and essential nutrients. Nevertheless, the contributions of these apparent symbionts to digestive physiology and nutritional ecology remain uncharacterized in most beetle lineages. Results: Through parallel transcriptome profiling of beetle- and microbial- derived mRNAs, we demonstrate that the midgut microbiome of the Asian longhorned beetle (Anoplophora glabripennis), a member of the beetle family Cerambycidae, is enriched in biosynthetic pathways for the synthesis of essential amino acids, vitamins, and sterols. Consequently, the midgut microbiome of A. glabripennis can provide essential nutrients that the beetle cannot obtain from its woody diet or synthesize itself. The beetle gut microbiota also produce their own suite of transcripts that can enhance lignin degradation, degrade hemicellulose, and ferment xylose and wood sugars. An abundance of cellulases from several glycoside hydrolase families are expressed endogenously by A. glabripennis, as well as transcripts that allow the beetle to convert microbe-synthesized essential amino acids into non-essential amino acids. A. glabripennis and its gut microbes likely collaborate to digest carbohydrates and convert released sugars and amino acid intermediates into essential nutrients otherwise lacking from their woody host plants. Conclusions: The nutritional provisioning capabilities of the A. glabripennis gut microbiome may contribute to the beetles’ unusually broad host range. The presence of some of the same microbes in the guts of other Cerambycidae and other wood-feeding beetles suggests that partnerships with microbes may be a facilitator of evolutionary radiations in beetles, as in certain other groups of insects, allowing access to novel food sources through enhanced nutritional provisioning

Genome of the Asian longhorned beetle (Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetle-plant interface

Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle

Endocytosis of HIV-1 activates plasmacytoid dendritic cells via Toll-like receptor– viral RNA interactions

HIV-1 directly activates human plasmacytoid DCs (pDCs) by upregulating the expression of costimulatory and MHC molecules and maturation markers, increasing T cell stimulatory activity, and inducing the production of type I interferons and TNF-α. A consequence of this activation is the bystander maturation of myeloid DCs and overall enhancement of antigen-presenting function. However, little is known about the mechanism(s) of pDC activation by HIV-1. Here we demonstrate by in vitro studies that IFN-α production by pDC in response to HIV-1 requires at least 2 interactions between the cell and virus. Initially, envelope-CD4 interactions mediate endocytosis of HIV-1, as demonstrated through the use of inhibitors of binding, fusion, endocytosis, and endosomal acidification. Subsequently, endosomally delivered viral nucleic acids, particularly RNA, stimulate pDCs through TLRs, as activation is reproduced with purified genomic RNA but not viral RNA packaging–deficient HIV-1 and blocked with different inhibitory TLR ligands. Finally, by using genetic complementation, we show that TLR7 is the likely primary target. Viral RNA rather than DNA in early retrotranscripts appears to be the active factor in HIV-1 that induces IFN-α secretion by pDCs. Since the decline in pDCs in chronic HIV-1 infection is associated with high viral loads and opportunistic infections, exploiting this natural adjuvant activity of HIV-1 RNA might be useful in the development of vaccines for the prevention of AIDS