637 research outputs found
Understanding Terrorist Organizations with a Dynamic Model
Terrorist organizations change over time because of processes such as
recruitment and training as well as counter-terrorism (CT) measures, but the
effects of these processes are typically studied qualitatively and in
separation from each other. Seeking a more quantitative and integrated
understanding, we constructed a simple dynamic model where equations describe
how these processes change an organization's membership. Analysis of the model
yields a number of intuitive as well as novel findings. Most importantly it
becomes possible to predict whether counter-terrorism measures would be
sufficient to defeat the organization. Furthermore, we can prove in general
that an organization would collapse if its strength and its pool of foot
soldiers decline simultaneously. In contrast, a simultaneous decline in its
strength and its pool of leaders is often insufficient and short-termed. These
results and other like them demonstrate the great potential of dynamic models
for informing terrorism scholarship and counter-terrorism policy making.Comment: To appear as Springer Lecture Notes in Computer Science v2:
vectorized 4 figures, fixed two typos, more detailed bibliograph
THE ELEVENTH AND TWELFTH DATA RELEASES OF THE SLOAN DIGITAL SKY SURVEY: FINAL DATA FROM SDSS-III
Citation: Alam, S., Albareti, F. D., Prieto, C. A., Anders, F., Anderson, S. F., Anderton, T., . . . Zhu, G. T. (2015). THE ELEVENTH AND TWELFTH DATA RELEASES OF THE SLOAN DIGITAL SKY SURVEY: FINAL DATA FROM SDSS-III. Astrophysical Journal Supplement Series, 219(1), 27. doi:10.1088/0067-0049/219/1/12The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12 adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 deg(2) of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include the measured abundances of 15 different elements for each star. In total, SDSS-III added 5200 deg(2) of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 deg(2); 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra.Additional Authors: Berlind, A. A.;Beutler, F.;Bhardwaj, V.;Bird, J. C.;Bizyaev, D.;Blake, C. H.;Blanton, M. R.;Blomqvist, M.;Bochanski, J. J.;Bolton, A. S.;Bovy, J.;Bradley, A. S.;Brandt, W. N.;Brauer, D. E.;Brinkmann, J.;Brown, P. J.;Brownstein, J. R.;Burden, A.;Burtin, E.;Busca, N. G.;Cai, Z.;Capozzi, D.;Rosell, A. C.;Carr, M. A.;Carrera, R.;Chambers, K. C.;Chaplin, W. J.;Chen, Y. C.;Chiappini, C.;Chojnowski, S. D.;Chuang, C. H.;Clerc, N.;Comparat, J.;Covey, K.;Croft, R. A. C.;Cuesta, A. J.;Cunha, K.;da Costa, L. N.;Da Rio, N.;Davenport, J. R. A.;Dawson, K. S.;De Lee, N.;Delubac, T.;Deshpande, R.;Dhital, S.;Dutra-Ferreira, L.;Dwelly, T.;Ealet, A.;Ebelke, G. L.;Edmondson, E. M.;Eisenstein, D. J.;Ellsworth, T.;Elsworth, Y.;Epstein, C. R.;Eracleous, M.;Escoffier, S.;Esposito, M.;Evans, M. L.;Fan, X. H.;Fernandez-Alvar, E.;Feuillet, D.;Ak, N. F.;Finley, H.;Finoguenov, A.;Flaherty, K.;Fleming, S. W.;Font-Ribera, A.;Foster, J.;Frinchaboy, P. M.;Galbraith-Frew, J. G.;Garcia, R. A.;Garcia-Hernandez, D. A.;Perez, A. E. G.;Gaulme, P.;Ge, J.;Genova-Santos, R.;Georgakakis, A.;Ghezzi, L.;Gillespie, B. A.;Girardi, L.;Goddard, D.;Gontcho, S. G. A.;Hernandez, J. I. G.;Grebel, E. K.;Green, P. J.;Grieb, J. N.;Grieves, N.;Gunn, J. E.;Guo, H.;Harding, P.;Hasselquist, S.;Hawley, S. L.;Hayden, M.;Hearty, F. R.;Hekker, S.;Ho, S.;Hogg, D. W.;Holley-Bockelmann, K.;Holtzman, J. A.;Honscheid, K.;Huber, D.;Huehnerhoff, J.;Ivans, II;Jiang, L. H.;Johnson, J. A.;Kinemuchi, K.;Kirkby, D.;Kitaura, F.;Klaene, M. A.;Knapp, G. R.;Kneib, J. P.;Koenig, X. P.;Lam, C. R.;Lan, T. W.;Lang, D. T.;Laurent, P.;Le Goff, J. M.;Leauthaud, A.;Lee, K. G.;Lee, Y. S.;Licquia, T. C.;Liu, J.;Long, D. C.;Lopez-Corredoira, M.;Lorenzo-Oliveira, D.;Lucatello, S.;Lundgren, B.;Lupton, R. H.;Mack, C. E.;Mahadevan, S.;Maia, M. A. G.;Majewski, S. R.;Malanushenko, E.;Malanushenko, V.;Manchado, A.;Manera, M.;Mao, Q. Q.;Maraston, C.;Marchwinski, R. C.;Margala, D.;Martell, S. L.;Martig, M.;Masters, K. L.;Mathur, S.;McBride, C. K.;McGehee, P. M.;McGreer, I. D.;McMahon, R. G.;Menard, B.;Menzel, M. L.;Merloni, A.;Meszaros, S.;Miller, A. A.;Miralda-Escude, J.;Miyatake, H.;Montero-Dorta, A. D.;More, S.;Morganson, E.;Morice-Atkinson, X.;Morrison, H. L.;Mosser, B.;Muna, D.;Myers, A. D.;Nandra, K.;Newman, J. A.;Neyrinck, M.;Nguyen, D. C.;Nichol, R. C.;Nidever, D. L.;Noterdaeme, P.;Nuza, S. E.;O'Connell, J. E.;O'Connell, R. W.;O'Connell, R.;Ogando, R. L. C.;Olmstead, M. D.;Oravetz, A. E.;Oravetz, D. J.;Osumi, K.;Owen, R.;Padgett, D. L.;Padmanabhan, N.;Paegert, M.;Palanque-Delabrouille, N.;Pan, K. K.;Parejko, J. K.;Paris, I.;Park, C.;Pattarakijwanich, P.;Pellejero-Ibanez, M.;Pepper, J.;Percival, W. J.;Perez-Fournon, I.;Perez-Rafols, I.;Petitjean, P.;Pieri, M. M.;Pinsonneault, M. H.;de Mello, G. F. P.;Prada, F.;Prakash, A.;Price-Whelan, A. M.;Protopapas, P.;Raddick, M. J.;Rahman, M.;Reid, B. A.;Rich, J.;Rix, H. W.;Robin, A. C.;Rockosi, C. M.;Rodrigues, T. S.;Rodriguez-Torres, S.;Roe, N. A.;Ross, A. J.;Ross, N. P.;Rossi, G.;Ruan, J. J.;Rubino-Martin, J. A.;Rykoff, E. S.;Salazar-Albornoz, S.;Salvato, M.;Samushia, L.;Sanchez, A. G.;Santiago, B.;Sayres, C.;Schiavon, R. P.;Schlegel, D. J.;Schmidt, S. J.;Schneider, D. P.;Schultheis, M.;Schwope, A. D.;Scoccola, C. G.;Scott, C.;Sellgren, K.;Seo, H. J.;Serenelli, A.;Shane, N.;Shen, Y.;Shetrone, M.;Shu, Y. P.;Aguirre, V. S.;Sivarani, T.;Skrutskie, M. F.;Slosar, A.;Smith, V. V.;Sobreira, F.;Souto, D.;Stassun, K. G.;Steinmetz, M.;Stello, D.;Strauss, M. A.;Streblyanska, A.;Suzuki, N.;Swanson, M. E. C.;Tan, J. C.;Tayar, J.;Terrien, R. C.;Thakar, A. R.;Thomas, D.;Thomas, N.;Thompson, B. A.;Tinker, J. L.;Tojeiro, R.;Troup, N. W.;Vargas-Magana, M.;Vazquez, J. A.;Verde, L.;Viel, M.;Vogt, N. P.;Wake, D. A.;Wang, J.;Weaver, B. A.;Weinberg, D. H.;Weiner, B. J.;White, M.;Wilson, J. C.;Wisniewski, J. P.;Wood-Vasey, W. M.;Yeche, C.;York, D. G.;Zakamska, N. L.;Zamora, O.;Zasowski, G.;Zehavi, I.;Zhao, G. B.;Zheng, Z.;Zhou, X.;Zhou, Z. M.;Zou, H.;Zhu, G. T
Modulation of enhancer looping and differential gene targeting by Epstein-Barr virus transcription factors directs cellular reprogramming
Epstein-Barr virus (EBV) epigenetically reprogrammes B-lymphocytes to drive immortalization and facilitate viral persistence. Host-cell transcription is perturbed principally through the actions of EBV EBNA 2, 3A, 3B and 3C, with cellular genes deregulated by specific combinations of these EBNAs through unknown mechanisms. Comparing human genome binding by these viral transcription factors, we discovered that 25% of binding sites were shared by EBNA 2 and the EBNA 3s and were located predominantly in enhancers. Moreover, 80% of potential EBNA 3A, 3B or 3C target genes were also targeted by EBNA 2, implicating extensive interplay between EBNA 2 and 3 proteins in cellular reprogramming. Investigating shared enhancer sites neighbouring two new targets (WEE1 and CTBP2) we discovered that EBNA 3 proteins repress transcription by modulating enhancer-promoter loop formation to establish repressive chromatin hubs or prevent assembly of active hubs. Re-ChIP analysis revealed that EBNA 2 and 3 proteins do not bind simultaneously at shared sites but compete for binding thereby modulating enhancer-promoter interactions. At an EBNA 3-only intergenic enhancer site between ADAM28 and ADAMDEC1 EBNA 3C was also able to independently direct epigenetic repression of both genes through enhancer-promoter looping. Significantly, studying shared or unique EBNA 3 binding sites at WEE1, CTBP2, ITGAL (LFA-1 alpha chain), BCL2L11 (Bim) and the ADAMs, we also discovered that different sets of EBNA 3 proteins bind regulatory elements in a gene and cell-type specific manner. Binding profiles correlated with the effects of individual EBNA 3 proteins on the expression of these genes, providing a molecular basis for the targeting of different sets of cellular genes by the EBNA 3s. Our results therefore highlight the influence of the genomic and cellular context in determining the specificity of gene deregulation by EBV and provide a paradigm for host-cell reprogramming through modulation of enhancer-promoter interactions by viral transcription factors
Upregulation of the cell-cycle regulator RGC-32 in Epstein-Barr virus-immortalized cells
Epstein-Barr virus (EBV) is implicated in the pathogenesis of multiple human tumours of lymphoid and epithelial origin. The virus infects and immortalizes B cells establishing a persistent latent infection characterized by varying patterns of EBV latent gene expression (latency 0, I, II and III). The CDK1 activator, Response Gene to Complement-32 (RGC-32, C13ORF15), is overexpressed in colon, breast and ovarian cancer tissues and we have detected selective high-level RGC-32 protein expression in EBV-immortalized latency III cells. Significantly, we show that overexpression of RGC-32 in B cells is sufficient to disrupt G2 cell-cycle arrest consistent with activation of CDK1, implicating RGC-32 in the EBV transformation process. Surprisingly, RGC-32 mRNA is expressed at high levels in latency I Burkitt's lymphoma (BL) cells and in some EBV-negative BL cell-lines, although RGC-32 protein expression is not detectable. We show that RGC-32 mRNA expression is elevated in latency I cells due to transcriptional activation by high levels of the differentially expressed RUNX1c transcription factor. We found that proteosomal degradation or blocked cytoplasmic export of the RGC-32 message were not responsible for the lack of RGC-32 protein expression in latency I cells. Significantly, analysis of the ribosomal association of the RGC-32 mRNA in latency I and latency III cells revealed that RGC-32 transcripts were associated with multiple ribosomes in both cell-types implicating post-initiation translational repression mechanisms in the block to RGC-32 protein production in latency I cells. In summary, our results are the first to demonstrate RGC-32 protein upregulation in cells transformed by a human tumour virus and to identify post-initiation translational mechanisms as an expression control point for this key cell-cycle regulator
The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey
The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic
data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data
release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median
z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar
spectra, along with the data presented in previous data releases. These spectra
were obtained with the new BOSS spectrograph and were taken between 2009
December and 2011 July. In addition, the stellar parameters pipeline, which
determines radial velocities, surface temperatures, surface gravities, and
metallicities of stars, has been updated and refined with improvements in
temperature estimates for stars with T_eff<5000 K and in metallicity estimates
for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars
presented in DR8, including stars from SDSS-I and II, as well as those observed
as part of the SDSS-III Sloan Extension for Galactic Understanding and
Exploration-2 (SEGUE-2).
The astrometry error introduced in the DR8 imaging catalogs has been
corrected in the DR9 data products. The next data release for SDSS-III will be
in Summer 2013, which will present the first data from the Apache Point
Observatory Galactic Evolution Experiment (APOGEE) along with another year of
data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at
http://www.sdss3.org/dr
TLR-4 ligation of dendritic cells is sufficient to drive pathogenic T cell function in experimental autoimmune encephalomyelitis
<p>Abstract</p> <p>Background</p> <p>Experimental autoimmune encephalomyelitis (EAE) depends on the initial activation of CD4<sup>+</sup> T cells responsive to myelin autoantigens. The key antigen presenting cell (APC) population that drives the activation of naïve T cells most efficiently is the dendritic cell (DC). As such, we should be able to trigger EAE by transfer of DC that can present the relevant autoantigen(s). Despite some sporadic reports, however, models of DC-driven EAE have not been widely adopted. We sought to test the feasibility of this approach and whether activation of the DC by toll-like receptor (TLR)-4 ligation was a sufficient stimulus to drive EAE.</p> <p>Findings</p> <p>Host mice were seeded with myelin basic protein (MBP)-reactive CD4+ T cells and then were injected with DC that could present the relevant MBP peptide which had been exposed to lipopolysaccharide as a TLR-4 agonist. We found that this approach induced robust clinical signs of EAE.</p> <p>Conclusions</p> <p>DC are sufficient as APC to effectively drive the differentiation of naïve myelin-responsive T cells into autoaggressive effector T cells. TLR-4-stimulation can activate the DC sufficiently to deliver the signals required to drive the pathogenic function of the T cell. These models will allow the dissection of the molecular requirements of the initial DC-T cell interaction in the lymphoid organs that ultimately leads to autoimmune pathology in the central nervous system.</p
Subnational climate entrepreneurship: innovative climate action in California and São Paulo
The distinct role of subnational governments such as states and provinces in addressing climate change has been increasingly acknowledged. But while most studies investigate the causes and consequences of particular governments’ actions and networking activities, this article argues that subnational governments can develop climate action as a collective entrepreneurial activity. Addressing many elements explored in this special issue, it focuses on the second question and identifies climate entrepreneurship in two subnational governments—the states of California (USA) and São Paulo (Brazil). Examining internal action, as well as interaction with local authorities, national governments and the international regime, entrepreneurial activities are identified in the invention, diffusion and evaluation of subnational climate policy in each case. The article draws from the recent scholarship on policy innovation, entrepreneurship and climate governance. It contributes to the literature by exploring entrepreneurial subnational government activity in addressing climate change and expanding the understanding of the effects of policy innovation at the subnational level
Superfund, Hedonics, and the Scales of Environmental Justice
Environmental justice (EJ) is prominent in environmental policy, yet EJ research is plagued by debates over methodological procedures. A well-established economic approach, the hedonic price method, can offer guidance on one contentious aspect of EJ research: the choice of the spatial unit of analysis. Environmental managers charged with preventing or remedying inequities grapple with these framing problems. This article reviews the theoretical and empirical literature on unit choice in EJ, as well as research employing hedonic pricing to assess the spatial extent of hazardous waste site impacts. The insights from hedonics are demonstrated in a series of EJ analyses for a national inventory of Superfund sites. First, as evidence of injustice exhibits substantial sensitivity to the choice of spatial unit, hedonics suggests some units conform better to Superfund impacts than others. Second, hedonic estimates for a particular site can inform the design of appropriate tests of environmental inequity for that site. Implications for policymakers and practitioners of EJ analyses are discussed
Grazing Systems Demonstration to Optimise Pasture Utilisation and Stocking Rate in Mediterranean Environments of Southern Australia
Differentiation and displacement: Unpicking the relationship between accounts of illness and social structure
This article seeks to unpack the relationship between social structure and accounts of illness. Taking dentine hypersensitivity as an example, this article explores the perspective that accounts of illness are sense-making processes that draw on a readily available pool of meaning. This pool of meaning is composed of a series of distinctions that make available a range of different lines of communication and action about such conditions. Such lines of communication are condensed and preserved over time and are often formed around a concept and its counter concept. The study of such processes is referred to as semantic analysis and involves drawing on the tools and techniques of conceptual history. This article goes on to explore how the semantics of dentine hypersensitivity developed. It illustrates how processes of social differentiation led to the concept being separated from the more dominant concept of dentine sensitivity and how it was medicalised, scientised and economised. In short, this study seeks to present the story of how society has developed a specific language for communicating about sensitivity and hypersensitivity in teeth. In doing so, it proposes that accounts of dentine hypersensitivity draw on lines of communication that society has preserved over time
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