239 research outputs found

    Real Intentions and Virtual Wrongs

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    In this thesis, I answer the gamer\u27s dilemma or the inability to find a moral distinction between virtual pedophilia and virtual murder. I expand virtual pedophilia to virtual rape to address increasing rates of sexual harassment and assault in virtual reality. In this thesis, I 1) explain what occurs when one engages in virtual rape; 2) identify relevant moral differences between physical rape and virtual rape; 3) challenge the existing relationship between committing harm and wrong in the case of rape; and 4) argue that virtual rape is morally reprehensible due to the agent’s intention to utilize a person as a mere tool for pleasure

    Participatory Research and Community Organizing

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    The paper summarizes the political economy of knowledge production in an increasingly privatized, postindustrial world of knowledge society. This analysis is linked to the emergence of participatory research movements. It argues that the participatory approach to community research offers epistemology and methodology that address people, power and praxis in our postmodern, information society. The paper then describes howa participatory research project is carried out in community practice, articulating key moments and the roles of the researcher and participants. In order to develop this understanding further, it examines the efforts of two specific projects and shows how knowledge production can serve as a conceptual entry point in community organizing through which people make choices, shape action, and create social movements

    Preparative Synthesis of dTDP-L-Rhamnose Through Combined Enzymatic Pathways

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    dTDP-L-rhamnose, an important precursor of O-antigen, was prepared on a large scale from dTMP by executing an one-pot reaction in which six enzymes are involved. Two enzymes, dTDP-4-keto-6-deoxy-D-glucose 3,5-epimerase and dTDP-4-keto-rhamnose reductase, responsible for the conversion of dTDP-4-keto-6-deoxy- D-glucose to dTDP-L-rhamnose, were isolated from their putative sequences in the genome of Mesorhizobium loti, functionally expressed in Escherichia coli, and their enzymatic activities were identified. The two enzymes were combined with an enzymatic process for dTDP-4- keto-6-deoxy-D-glucose involving TMP kinase, acetate kinase, dTDP-glucose synthase, and dTDP-glucose 4,6- dehydratase, which allowed us to achieve a preparative scale synthesis of dTDP-L-rhamnose using dTMP and glucose-1-phosphate as starting materials. About 82% yield of dTDP-L-rhamnose was obtained based on initial dTMP concentration at 20 mM dTMP, 1 mM ATP, 10 mM NADH, 60 mM acetyl phosphate, and 80 mM glucose-1- phosphate. From the reaction with 20 ml volume, approximately 180 mg of dTDP-L-rhamnose was obtained in an overall yield of 60% after two-step purification, that is, anion exchange chromatography and gel filtration for desalting. The purified product was identifiedbyHPLC, ESI-MS,andNMR,showingabout95%purity

    Comparative study on melanin production and collagen expression profile of polyphenols and their glycosides

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    A total of twenty different polyphenol aglycones and their biochemically synthesized glycoside derivatives were accessed for cell toxicity, collagen synthesis and melanin content inhibition assays to illustrate the double-edged sword role of glycobiology, in particular, modification of hydroxyl group in polyphenol structure without glycone moiety over anti-aging and defense to oxidative stress in skin dermatology. All molecules at (0.1-200) µM concentration inhibited cell growth in a dose dependent manner on human dermal fibroblast (HDF) and melanoma skin cancer (B16F10) cells. At lower concentrations of (0.1-10) µM, most of the molecules were nontoxic to HDF cells, while the same molecules were toxic to B16F10 cells except astilbin (6), baicalein (13), baicalein 7-O-β-D-glucoside (14) and mangostin (18). Results showed that two molecules, quercetin (1) and diosmin (17), inhibited melanogenesis in α-melanocyte stimulating hormone (α-MSH)-stimulated melanoma skin cancer cells (B16F10) in comparison to the control at 0.1 µM concentration, indicating the possible use of these molecules in skin-whitening products. Similarly, the maintenance of collagen in HDF cells was found to be highly activated by the compound, kaempferol (11), at 1.0 µM concentration, at which the cell viability was above 95%. Compound 1, apigenin 7-O-β-D-glucoside (10) andbaicalein (13) exhibited comparable collagen biosynthesis activity to control with significantly low cell toxicity

    One-pot Enzymatic Synthesis of Deoxy-thymidine-diphosphate (TDP)-2-deoxy-∝-d-glucose Using Phosphomannomutase

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    Production of deoxy-thymidine-diphosphate (TDP)-sugars as substrates of glycosyltransferases, has been one of main hurdles for combinatorial antibiotic biosynthesis, which combines sugar moiety with aglycon of various antibiotics. Here, we report the one-pot enzymatic synthesis of TDP-2-deoxy-glucose employing high efficient TMP kinase (TMK; E.C. 2.7.2.12), acetate kinase (ACK; E.C. 2.7.1.21), and TDP-glucose synthase (TGS; E.C. 2.7.7.24) with phosphomannomutase (PMM; E.C. 5.4.2.8). In this study, replacing phosphoglucomutase (PGM; E.C. 5.4.2) by PMM from Escherichia coli gave four times higher specific activity on 2-deoxy-6-phosphate glucose, suggesting that the activity on 2-deoxy-glucose-6-phosphate was mainly affected by PMM activity, not PGM activity. Using an in vitro system starting from TMP and 2-deoxy-glucose-6-phosphate glucose, TDP-2-deoxy-glucose (63% yield) was successfully synthesized. Considering low productivity of NDP-sugars from cheap starting materials, this paper showed how production of NDP-sugars could be enhanced by controlling mutase activity

    Metabolic Engineering of Escherichia coli for Enhanced Production of Naringenin 7-Sulfate and Its Biological Activities

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    Flavonoids are one of the predominant groups of plant polyphenols, and these compounds have significant effects on human health and nutrition. Sulfated flavonoids have more favorable attributes compared to their parent compounds such as increased solubility, stability, and bioavailability. In this research, we developed a microbial system to produce sulfated naringenin using Escherichia coli expressing a sulfotransferase (ST) from Arabidopsis thaliana (At2g03770). This wild-type strain was used as a model system for testing clustered regularly interspaced short palindromic repeats (CRISPR) interference (CRISPRi) metabolic engineering strategies. Using synthetic sgRNA to mediate transcriptional repression of cysH, a gene encoding 3′-phosphoadenosine-5′-phosphosulfate (PAPS) ST, which is involved in sulfur metabolism, resulted in an increase in intracellular PAPS accumulation by over 3.28-fold without impairing cell growth. Moreover, naringenin 7-sulfate production by engineering E. coli with its cysH gene repressed in the open reading frame through CRISPRi was enhanced by 2.83-fold in compared with the wild-type control. To improve the efficiency of biotransformation, the concentration of SO42−, glucose, and substrate were optimized. The bioproductivity of naringenin 7-sulfate was 135.49 μM [∼143.1 mg (47.7 mg L-1)] in a 3-L fermenter at 36 h. These results demonstrated that the CRISPRi system was successfully applied for the first time in E. coli to develop an efficient microbial strain for production of a sulfated flavonoid. In addition, antibacterial and anticancer activities of naringenin 7-sulfate were investigated and found to be higher than the parent compound

    Methods for determining the CO2 removal capacity of enhanced weathering in agronomic settings

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    Recent analysis by the IPCC suggests that, across an array of scenarios, both GHG emissions reductions and various degrees of carbon removal will be required to achieve climate stabilization at a level that avoids the most dangerous climate changes in the future. Among a large number of options in the realm of natural climate solutions, atmospheric carbon dioxide removal (CDR) via enhanced silicate weathering (EW) in global working lands could, in theory, achieve billions of tons of CO2 removal each year. Despite such potential, however, scientific verification and field testing of this technology are still in need of significant advancement. Increasing the number of EW field trials can be aided by formal presentation of effective study designs and methodological approaches to quantifying CO2 removal. In particular, EW studies in working lands require interdisciplinary “convergence” research that links low temperature geochemistry and agronomy. Here, drawing on geologic and agronomic literature, as well as demonstration-scale research on quantifying EW, we provide an overview of (1) existing literature on EW experimentation as a CO2 removal technique, (2) agronomic and geologic approaches to studying EW in field settings, (3) the scientific bases and tradeoffs behind various techniques for quantifying CO2 removal and other relevant methodologies, and (4) the attributes of effective stakeholder engagement for translating scientific research in action. In doing so, we provide a guide for establishing interdisciplinary EW field trials, thereby advancing the verification of atmospheric CO2 in working lands through the convergence of geochemistry and agronomy

    Investigation of Early Protein Changes in the Urinary Bladder Following Partial Bladder Outlet Obstruction by Proteomic Approach

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    We investigated the pathophysiological mechanism by proteomic approach as a possible tool to detect the marker proteins to develop lower urinary tract symptoms following bladder outlet obstruction (BOO). Rats were randomized into 3 groups; control, sham operation and BOO groups. BOO group was divided into 1, 3, and 5 day-group. Conventional proteomics was performed with high resolution 2-D gel electrophoresis followed by computational image analysis and protein identification using mass spectrometry using rat urinary bladders. A comparison of bladder of BOO group with control bladder showed that three proteins of optineurin, thioredoxin and preprohaptoglobin were over-expressed in the bladder of BOO group. In addition, four proteins, such as peroxiredoxin 2, transgelin, hippocampal cholinergic neurostimulating peptide (HCNP) and beta-galactoside-binding lectin, were under-expressed in the bladder of BOO group. These data supported that down-regulation of HCNP might make detrusor muscle be supersensitive to acetylcholine, up-regulation of optineurin means the protection of nerve injury, and down-regulation of transgelin means the decreased contractility of detrusor muscle. Beside these proteins, other proteins are related to oxidative stress or have a nonspecific function in this study. However more information is needed in human bladder tissue for clinical usage
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