128 research outputs found

    Financing Direct Democracy: Revisiting the Research on Campaign Spending and Citizen Initiatives

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    The conventional view in the direct democracy literature is that spending against a measure is more effective than spending in favor of a measure, but the empirical results underlying this conclusion have been questioned by recent research. We argue that the conventional finding is driven by the endogenous nature of campaign spending: initiative proponents spend more when their ballot measure is likely to fail. We address this endogeneity by using an instrumental variables approach to analyze a comprehensive dataset of ballot propositions in California from 1976 to 2004. We find that both support and opposition spending on citizen initiatives have strong, statistically significant, and countervailing effects. We confirm this finding by looking at time series data from early polling on a subset of these measures. Both analyses show that spending in favor of citizen initiatives substantially increases their chances of passage, just as opposition spending decreases this likelihood

    CMB-S4 Science Book, First Edition

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    This book lays out the scientific goals to be addressed by the next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned to consist of dedicated telescopes at the South Pole, the high Chilean Atacama plateau and possibly a northern hemisphere site, all equipped with new superconducting cameras. CMB-S4 will dramatically advance cosmological studies by crossing critical thresholds in the search for the B-mode polarization signature of primordial gravitational waves, in the determination of the number and masses of the neutrinos, in the search for evidence of new light relics, in constraining the nature of dark energy, and in testing general relativity on large scales

    Modelling Cell Polarization Driven by Synthetic Spatially Graded Rac Activation

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    The small GTPase Rac is known to be an important regulator of cell polarization, cytoskeletal reorganization, and motility of mammalian cells. In recent microfluidic experiments, HeLa cells endowed with appropriate constructs were subjected to gradients of the small molecule rapamycin leading to synthetic membrane recruitment of a Rac activator and direct graded activation of membrane-associated Rac. Rac activation could thus be triggered independent of upstream signaling mechanisms otherwise responsible for transducing activating gradient signals. The response of the cells to such stimulation depended on exceeding a threshold of activated Rac. Here we develop a minimal reaction-diffusion model for the GTPase network alone and for GTPase-phosphoinositide crosstalk that is consistent with experimental observations for the polarization of the cells. The modeling suggests that mutual inhibition is a more likely mode of cell polarization than positive feedback of Rac onto its own activation. We use a new analytical tool, Local Perturbation Analysis, to approximate the partial differential equations by ordinary differential equations for local and global variables. This method helps to analyze the parameter space and behaviour of the proposed models. The models and experiments suggest that (1) spatially uniform stimulation serves to sensitize a cell to applied gradients. (2) Feedback between phosphoinositides and Rho GTPases sensitizes a cell. (3) Cell lengthening/flattening accompanying polarization can increase the sensitivity of a cell and stabilize an otherwise unstable polarization

    Upper ocean oxygenation dynamics from I/Ca ratios during the Cenomanian-Turonian OAE 2

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    Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 30 (2015): 510–526, doi:10.1002/2014PA002741.Global warming lowers the solubility of gases in the ocean and drives an enhanced hydrological cycle with increased nutrient loads delivered to the oceans, leading to increases in organic production, the degradation of which causes a further decrease in dissolved oxygen. In extreme cases in the geological past, this trajectory has led to catastrophic marine oxygen depletion during the so-called oceanic anoxic events (OAEs). How the water column oscillated between generally oxic conditions and local/global anoxia remains a challenging question, exacerbated by a lack of sensitive redox proxies, especially for the suboxic window. To address this problem, we use bulk carbonate I/Ca to reconstruct subtle redox changes in the upper ocean water column at seven sites recording the Cretaceous OAE 2. In general, I/Ca ratios were relatively low preceding and during the OAE interval, indicating deep suboxic or anoxic waters exchanging directly with near-surface waters. However, individual sites display a wide range of initial values and excursions in I/Ca through the OAE interval, reflecting the importance of local controls and suggesting a high spatial variability in redox state. Both I/Ca and an Earth System Model suggest that the northeast proto-Atlantic had notably higher oxygen levels in the upper water column than the rest of the North Atlantic, indicating that anoxia was not global during OAE 2 and that important regional differences in redox conditions existed. A lack of correlation with calcium, lithium, and carbon isotope records suggests that neither enhanced global weathering nor carbon burial was a dominant control on the I/Ca proxy during OAE 2.Z.L. thanks NSF OCE 1232620. J.D.O. is supported by an Agouron Postdoctoral Fellowship. T.W.L. acknowledges support from the NSF-EAR and NASA-NAI. A.R. thanks the support of NERC via NE/J01043X/1.2015-11-1

    Influence of ARHGEF3 and RHOA Knockdown on ACTA2 and Other Genes in Osteoblasts and Osteoclasts

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    Osteoporosis is a common bone disease that has a strong genetic component. Genome-wide linkage studies have identified the chromosomal region 3p14-p22 as a quantitative trait locus for bone mineral density (BMD). We have previously identified associations between variation in two related genes located in 3p14-p22, ARHGEF3 and RHOA, and BMD in women. In this study we performed knockdown of these genes using small interfering RNA (siRNA) in human osteoblast-like and osteoclast-like cells in culture, with subsequent microarray analysis to identify genes differentially regulated from a list of 264 candidate genes. Validation of selected findings was then carried out in additional human cell lines/cultures using quantitative real-time PCR (qRT-PCR). The qRT-PCR results showed significant down-regulation of the ACTA2 gene, encoding the cytoskeletal protein alpha 2 actin, in response to RHOA knockdown in both osteoblast-like (P<0.001) and osteoclast-like cells (P = 0.002). RHOA knockdown also caused up-regulation of the PTH1R gene, encoding the parathyroid hormone 1 receptor, in Saos-2 osteoblast-like cells (P<0.001). Other findings included down-regulation of the TNFRSF11B gene, encoding osteoprotegerin, in response to ARHGEF3 knockdown in the Saos-2 and hFOB 1.19 osteoblast-like cells (P = 0.003– 0.02), and down-regulation of ARHGDIA, encoding the Rho GDP dissociation inhibitor alpha, in response to RHOA knockdown in osteoclast-like cells (P<0.001). These studies identify ARHGEF3 and RHOA as potential regulators of a number of genes in bone cells, including TNFRSF11B, ARHGDIA, PTH1R and ACTA2, with influences on the latter evident in both osteoblast-like and osteoclast-like cells. This adds further evidence to previous studies suggesting a role for the ARHGEF3 and RHOA genes in bone metabolism

    Competition and Combative Advertising: An Historical Analysis

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    Fred K. Beard (PhD, University of Oklahoma) is a professor of advertising in the Gaylord College of Journalism and Mass Communication, University of Oklahoma. His research interests include comparative advertising, advertising humor, and advertising history. His work has appeared in the Journal of Advertising, the Journal of Advertising Research, the Journal of Business Ethics, the Journal of Business Research, Journalism History, the Journal of Historical Research in Marketing, the Journal of Macromarketing, and the Journal of Marketing Communications, among others.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
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