Toro Times: Raising Our Voices!

During the Spring 2019 semester, Dr. Noah Asher Golden\u27s Teaching of Writing K-12 students partnered with the Journalism class at Yorba Academy for the Arts. Through collaboration over a four-month period, Chapman\u27s future teachers and Yorba\u27s junior high journalists engaged a deep writing process to write a series of features, editorials, and news articles related to a number of global issues. Thank you to Principal Preciado-Martin, former principal Tracy Knibb, Mrs. Andrea Lopez, Mrs. Kori Shelton, and the Lloyd E. and Elisabeth H. Klein Family Foundation for supporting this project.https://digitalcommons.chapman.edu/yorba-chapman/1004/thumbnail.jp

Reduction of aqueous CO_2 to 1-Propanol at MoS_2 electrodes

Reduction of carbon dioxide in aqueous electrolytes at single-crystal MoS_2 or thin-film MoS_2 electrodes yields 1-propanol as the major CO_2 reduction product, along with hydrogen from water reduction as the predominant reduction process. Lower levels of formate, ethylene glycol, and t-butanol were also produced. At an applied potential of −0.59 V versus a reversible hydrogen electrode, the Faradaic efficiencies for reduction of CO_2 to 1-propanol were ∼3.5% for MoS2single crystals and ∼1% for thin films with low edge-site densities. Reduction of CO_2 to 1-propanol is a kinetically challenging reaction that requires the overall transfer of 18 e– and 18 H+ in a process that involves the formation of 2 C–C bonds. NMR analyses using ^(13)CO_2 showed the production of ^(13)C-labeled 1-propanol. In all cases, the vast majority of the Faradaic current resulted in hydrogen evolution via water reduction. H_2S was detected qualitatively when single-crystal MoS_2 electrodes were used, indicating that some desulfidization of single crystals occurred under these conditions

Ecological and Anthropogenic Spatial Gradients Shape Patterns of Dispersal of Foot-and-Mouth Disease Virus in Uganda

Using georeferenced phylogenetic trees, phylogeography allows researchers to elucidate interactions between environmental heterogeneities and patterns of infectious disease spread. Concordant with the increasing availability of pathogen genetic sequence data, there is a growing need for tools to test epidemiological hypotheses in this field. In this study, we apply tools traditionally used in ecology to elucidate the epidemiology of foot-and-mouth disease virus (FMDV) in Uganda. We analyze FMDV serotype O genetic sequences and their corresponding spatiotemporal metadata from a cross-sectional study of cattle. We apply step selection function (SSF) models, typically used to study wildlife habitat selection, to viral phylogenies to show that FMDV is more likely to be found in areas of low rainfall. Next, we use a novel approach, a resource gradient function (RGF) model, to elucidate characteristics of viral source and sink areas. An RGF model applied to our data reveals that areas of high cattle density and areas near livestock markets may serve as sources of FMDV dissemination in Uganda, and areas of low rainfall serve as viral sinks that experience frequent reintroductions. Our results may help to inform risk-based FMDV control strategies in Uganda. More broadly, these tools advance the phylogenetic toolkit, as they may help to uncover patterns of spread of other organisms for which genetic sequences and corresponding spatiotemporal metadata exist

Phylogeographic analysis of foot‐and‐mouth disease virus serotype O dispersal and associated drivers in East Africa

The continued endemicity of foot and mouth disease virus (FMDV) in East Africa has significant implications for livestock production and poverty reduction, yet its complex epidemiology in endemic settings remains poorly understood. Identifying FMDV dispersal routes and drivers of transmission is key to improved control strategies. Environmental heterogeneity and anthropogenic drivers (e.g. demand for animal products) can impact viral spread by influencing host movements. Here, we utilized FMDV serotype O VP1 genetic sequences and corresponding spatiotemporal data in order to (i) infer the recent dispersal history, and (II) investigate the impact of external factors (cattle density, human population density, proximity to livestock markets, and drought) on dispersal velocity, location, and direction of FMDV serotype O in East Africa. We identified statistical evidence of long-distance transmission events, and we found that FMDV serotype O tends to remain circulating in areas of high cattle density, high human population density, and in close proximity to livestock markets. The latter two findings highlight the influence of anthropogenic factors on FMDV serotype O spread in this region. These findings contribute to the understanding of FMDV epidemiology in East Africa and can help guide improved control measures.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Phylogeographic analysis of foot-and-mouth disease virus serotype O dispersal and associated drivers in East Africa

The continued endemicity of foot and mouth disease virus (FMDV) in East Africa has significant implications for livestock production and poverty reduction, yet its complex epidemiology in endemic settings remains poorly understood. Identifying FMDV dispersal routes and drivers of transmission is key to improved control strategies. Environmental heterogeneity and anthropogenic drivers (e.g. demand for animal products) can impact viral spread by influencing host movements. Here, we utilized FMDV serotype O VP1 genetic sequences and corresponding spatiotemporal data in order to (i) infer the recent dispersal history, and (II) investigate the impact of external factors (cattle density, human population density, proximity to livestock markets, and drought) on dispersal velocity, location, and direction of FMDV serotype O in East Africa. We identified statistical evidence of long-distance transmission events, and we found that FMDV serotype O tends to remain circulating in areas of high cattle density, high human population density, and in close proximity to livestock markets. The latter two findings highlight the influence of anthropogenic factors on FMDV serotype O spread in this region. These findings contribute to the understanding of FMDV epidemiology in East Africa and can help guide improved control measures.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Acute Podocyte Vascular Endothelial Growth Factor (VEGF-A) Knockdown Disrupts alpha_Vbeta₃ Integrin Signaling in the Glomerulus

<div><p>Podocyte or endothelial cell VEGF-A knockout causes thrombotic microangiopathy in adult mice. To study the mechanism involved in acute and local injury caused by low podocyte VEGF-A we developed an inducible, podocyte-specific VEGF-A knockdown mouse, and we generated an immortalized podocyte cell line (VEGF^KD) that downregulates VEGF-A upon doxycycline exposure. <em>Tet-O-siVEGF:podocin-rtTA</em> mice express <em>VEGF</em> shRNA in podocytes in a doxycycline-regulated manner, decreasing VEGF-A mRNA and VEGF-A protein levels in isolated glomeruli to ∼20% of non-induced controls and urine VEGF-A to ∼30% of control values a week after doxycycline induction. Induced <em>tet-O-siVEGF:podocin-rtTA</em> mice developed acute renal failure and proteinuria, associated with mesangiolysis and microaneurisms. Glomerular ultrastructure revealed endothelial cell swelling, GBM lamination and podocyte effacement. VEGF knockdown decreased podocyte fibronectin and glomerular endothelial alpha_Vbeta₃ integrin <em>in vivo</em>. VEGF receptor-2 (VEGFR2) interacts with beta₃ integrin and neuropilin-1 in the kidney <em>in vivo</em> and in VEGF^KD podocytes. Podocyte VEGF knockdown disrupts alpha_Vbeta₃ integrin activation in glomeruli, detected by WOW1-Fab. VEGF silencing in cultured VEGF^KD podocytes downregulates fibronectin and disrupts alpha_Vbeta₃ integrin activation cell-autonomously. Collectively, these studies indicate that podocyte VEGF-A regulates alpha_Vbeta₃ integrin signaling in the glomerulus, and that podocyte VEGF knockdown disrupts alpha_Vbeta₃ integrin activity via decreased VEGFR2 signaling, thereby damaging the three layers of the glomerular filtration barrier, causing proteinuria and acute renal failure.</p> </div

Pertechnetate-Induced Addition of Sulfide in Small Olefinic Acids: Formation of [TcO(dimercaptosuccinate)₂]^5– and [TcO(mercaptosuccinate)₂]^3– Analogues

Technetium-99 (⁹⁹Tc) is important to the nuclear fuel cycle as a long-lived radionuclide produced in ∼6% fission yield from ²³⁵U or ²³⁹Pu. In its most common chemical form, namely, pertechnetate (⁹⁹TcO₄^–), it is environmentally mobile. In situ hydrogen sulfide reduction of pertechnetate has been proposed as a potential method to immobilize environmental ⁹⁹TcO₄^– that has entered the environment. Reactions of ⁹⁹TcO₄^– with sulfide in solution result in the precipitation of Tc₂S₇ except when olefinic acids, specifically fumaric or maleic acid, are present; a water-soluble ⁹⁹Tc species forms. NMR (¹H, ¹³C, and 2D methods) and X-ray absorption spectroscopy [XAS; near-edge (XANES) and extended fine structure (EXAFS)] studies indicate that sulfide adds across the olefinic bond to generate mercaptosuccinic acid (H₃MSA) and/or dimercaptosuccinic acid (H₄DMSA), which then chelate(s) the ⁹⁹Tc to form [⁹⁹TcO­(MSA)₂]^3–, [⁹⁹TcO­(DMSA)₂]^5–, or potentially [⁹⁹TcO­(MSA)­(DMSA)]^4–. 2D NMR methods allowed identification of the products by comparison to ⁹⁹Tc and nonradioactive rhenium standards. The rhenium standards allowed further identification by electrospray ionization mass spectrometry. ⁹⁹TcO₄^– is essential to the reaction because no sulfide addition occurs in its absence, as determined by NMR. Computational studies were performed to investigate the structures and stabilities of the potential products. Because olefinic acid is a component of the naturally occurring humic and fulvic acids found in soils and groundwater, the viability of in situ hydrogen sulfide reduction of environmental ⁹⁹TcO₄^– as an immobilization method is evaluated

Blood Pressure in <i>siVEGF</i> mice.

<p>Systolic blood pressure and diastolic blood pressure is normal in VEGF knockdown mice. In control period and VEGF knockdown period, values are mean ±SE in peak of activity (dark period) and rest (light period).</p