Mostrando recursos 21 - 40 de 8.894

  1. Bayesian nonlinear structural FE model and seismic input identification for damage assessment of civil structures

    Astroza, Rodrigo; Ebrahimian, Hamed; Li, Yong; Conte, Joel P.
    A methodology is proposed to update mechanics-based nonlinear finite element (FE) models of civil structures subjected to unknown input excitation. The approach allows to jointly estimate unknown time-invariant model parameters of a nonlinear FE model of the structure and the unknown time histories of input excitations using spatially-sparse output response measurements recorded during an earthquake event. The unscented Kalman filter, which circumvents the computation of FE response sensitivities with respect to the unknown model parameters and unknown input excitations by using a deterministic sampling approach, is employed as the estimation tool. The use of measurement data obtained from arrays of...

  2. Effects of biological, economic and management factors on tuna and billfish stock status

    Pons, Maite; Branch, Trevor A.; Melnychuk, Michael C.; Jensen, Olaf P.; Brodziak, Jon; Fromentin, Jean-marc; Harley, Shelton J.; Haynie, Alan C.; Kell, Laurie T.; Maunder, Mark N.; Parma, Ana M.; Restrepo, Victor R.; Sharma, Rishi; Ahrens, Robert; Hilborn, Ray
    Commercial tunas and billfishes (swordfish, marlins and sailfish) provide considerable catches and income in both developed and developing countries. These stocks vary in status from lightly exploited to rebuilding to severely depleted. Previous studies suggested that this variability could result from differences in life-history characteristics and economic incentives, but differences in exploitation histories and management measures also have a strong effect on current stock status. Although the status (biomass and fishing mortality rate) of major tuna and billfish stocks is well documented, the effect of these diverse factors on current stock status and the effect of management measures in rebuilding...

  3. Galaxy and Mass Assembly (GAMA): Probing the merger histories of massive galaxies via stellar populations

    Ferreras, I; Hopkins, AM; Gunawardhana, MLP; Sansom, AE; Owers, MS; Driver, S; Davies, L; Robotham, A; Taylor, EN; Konstantopoulos, I; Brough, S; Norberg, P; Croom, S; Loveday, J; Wang, L; Bremer, M
    © 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.The merging history of galaxies can be traced with studies of dynamically close pairs. These consist of a massive primary galaxy and a less massive secondary (or satellite) galaxy. The study of the stellar populations of secondary (lower mass) galaxies in close pairs provides a way to understand galaxy growth by mergers. Here we focus on systems involving at least one massive galaxy - with stellar mass above 1011M in the highly complete Galaxy and Mass Assembly (GAMA) survey. Our working sample comprises 2692 satellite...

  4. Uncanny History: Temporal Topology in the Post-Ottoman World

    Stewart, CW
    Post-Ottoman temporal topologies—cases where the past, present, and future may be bent around one another rather than ordered linearly—may produce uncanny histories. The uncanny is activated, as Freud noted, when something secret comes to light, but also when the expectations of a given genre are exceeded. In these cases, the genre of historicism has been violated. Rather than contending that the post-Ottoman world is entirely different from Western Europe, the examples here alert one to the presence of uncanny histories in many other places since historicism has nowhere managed to eradicate its alternatives. Unsettled pasts of violence and displacement and presents beset by ongoing tensions (political, economic, religious/ethnic)...

  5. Impact of Sex and Menopausal Status on Episodic Memory Circuitry in Early Midlife

    Jacobs, E. G.; Weiss, B. K.; Makris, N.; Buka, S. L.; Klibanski, A.; Goldstein, J. M.; Whitfield-Gabrieli, Susan
    Cognitive neuroscience of aging studies traditionally target participants age 65 and older. However, epidemiological surveys show that many women report increased forgetfulness earlier in the aging process, as they transition to menopause. In this population-based fMRI study, we stepped back by over a decade to characterize the changes in memory circuitry that occur in early midlife, as a function of sex and women's reproductive stage. Participants (N = 200; age range, 45–55) performed a verbal encoding task during fMRI scanning. Reproductive histories and serologic evaluations were used to determine menopausal status. Results revealed a pronounced impact of reproductive stage on...

  6. Galaxy and Mass Assembly (GAMA): Probing the merger histories of massive galaxies via stellar populations

    Ferreras, I; Hopkins, AM; Gunawardhana, MLP; Sansom, AE; Owers, MS; Driver, S; Davies, L; Robotham, A; Taylor, EN; Konstantopoulos, I; Brough, S; Norberg, P; Croom, S; Loveday, J; Wang, L; Bremer, M
    The merging history of galaxies can be traced with studies of dynamically close pairs. These consist of a massive primary galaxy and a less massive secondary (or satellite) galaxy. The study of the stellar populations of secondary (lower mass) galaxies in close pairs provides a way to understand galaxy growth by mergers. Here we focus on systems involving at least one massive galaxy – with stellar mass above 1011M⊙ in the highly complete Galaxy and Mass Assembly (GAMA) survey. Our working sample comprises 2692 satellite galaxy spectra (0.1 ≤ z ≤ 0.3). These spectra are combined into high S/N stacks,...

  7. Tracking the Evolution of Non-Small-Cell Lung Cancer.

    Jamal-Hanjani, M; Wilson, GA; McGranahan, N; Birkbak, NJ; Watkins, TBK; Veeriah, S; Shafi, S; Johnson, DH; Mitter, R; Rosenthal, R; Salm, M; Horswell, S; Escudero, M; Matthews, N; Rowan, A; Chambers, T; Moore, DA; Turajlic, S; Xu, H; Lee, S-M; Forster, MD; Ahmad, T; Hiley, CT; Abbosh, C; Falzon, M; Borg, E; Marafioti, T; Lawrence, D; Hayward, M; Kolvekar, S; Panagiotopoulos, N; Janes, SM; Thakrar, R; Ahmed, A; Blackhall, F; Summers, Y; Shah, R; Joseph, L; Quinn, AM; Crosbie, PA; Naidu, B; Middleton, G; Langman, G; Trotter, S; Nicolson, M; Remmen, H; Kerr, K; Chetty, M; Gomersall, L; Fennell, DA; Nakas, A; Rathinam, S; Anand, G; Khan, S; Russell, P; Ezhil, V; Ismail, B; Irvin-Sellers, M; Prakash, V; Lester, JF; Kornaszewska, M; Attanoos, R; Adams, H; Davies, H; Dentro, S; Taniere, P; O'Sullivan, B; Lowe, HL; Hartley, JA; Iles, N; Bell, H; Ngai, Y; Shaw, JA; Herrero, J; Szallasi, Z; Schwarz, RF; Stewart, A; Quezada, SA; Le Quesne, J; Van Loo, P; Dive, C; Hackshaw, A; Swanton, C; TRACERx Consortium,
    Background Among patients with non-small-cell lung cancer (NSCLC), data on intratumor heterogeneity and cancer genome evolution have been limited to small retrospective cohorts. We wanted to prospectively investigate intratumor heterogeneity in relation to clinical outcome and to determine the clonal nature of driver events and evolutionary processes in early-stage NSCLC. Methods In this prospective cohort study, we performed multiregion whole-exome sequencing on 100 early-stage NSCLC tumors that had been resected before systemic therapy. We sequenced and analyzed 327 tumor regions to define evolutionary histories, obtain a census of clonal and subclonal events, and assess the relationship between intratumor heterogeneity and...

  8. A study of flare assessment in systemic lupus erythematosus (SLE) based on paper patients.

    Isenberg, D; Sturgess, J; Allen, E; Aranow, C; Askanase, A; Sang-Cheol, B; Bernatsky, S; Bruce, I; Buyon, J; Cervera, R; Clarke, A; Dooley, MA; Fortin, P; Ginzler, E; Gladman, D; Hanly, J; Inanc, M; Jacobsen, S; Kamen, D; Khamashta, M; Lim, S; Manzi, S; Nived, O; Peschken, C; Petri, M; Kalunian, K; Rahman, A; Ramsey-Goldman, R; Ruiz-Irastorza, G; Sanchez-Guerrero, J; Steinsson, K; Sturfelt, G; Urowitz, M; van Vollenhoven, R; Wallace, DJ; Zoma, A; Merrill, J; Gordon, C
    OBJECTIVE: To determine the level of agreement of disease flare severity (distinguishing severe, moderate and mild flare and persistent disease activity) in a large paper patient exercise involving 988 individual cases of systemic lupus erythematosus. METHODS: 988 individual lupus case histories were assessed by three individual physicians. Complete agreement about the degree of flare (or persistent disease activity) was obtained in 451 cases (46%) and these provided the reference standard for the second part of the study. This component utilised three flare activity instruments (BILAG 2004, SELENA flare index (SFI) and the revised SELENA flare index (rSFI)). The 451 patient...

  9. Fragility assessment of a RC structure under tsunami actions via nonlinear static and dynamic analyses

    Petrone, C; Rossetto, T; Goda, K
    Current guidelines for design and assessment of buildings under tsunami actions do not explicitly state how to apply tsunami loads to buildings and which analysis methods to use in order to assess the structural response to the tsunami loads. In this paper, a reinforced concrete (RC) moment-resisting frame, which is designed as a tsunami evacuation building, is selected as a case study and subjected to simulated 2011 Tohoku tsunami waves. To assess tsunami impact on the model building, different nonlinear static analyses, i.e. constant-height pushover (CHPO) and variable-height pushover (VHPO), are compared with nonlinear dynamic analysis. The results of VHPO...

  10. Entangled histories

    Cotler, Jordan S.; Wilczek, Frank
    We introduce quantum history states and their mathematical framework, thereby reinterpreting and extending the consistent histories approach to quantum theory. Through thought experiments, we demonstrate that our formalism allows us to analyze a quantum version of history in which we reconstruct the past by observations. In particular, we can pass from measurements to inferences about 'what happened' in a way that is sensible and free of paradox. Our framework allows for a richer understanding of the temporal structure of quantum theory, and we construct history states that embody peculiar, non-classical correlations in time.

  11. The stellar mass assembly of galaxies in the Illustris simulation: growth by mergers and the spatial distribution of accreted stars

    Rodriguez-Gomez, Vicente; Pillepich, Annalisa; Sales, Laura V.; Genel, Shy; Zhu, Qirong; Wellons, Sarah; Nelson, Dylan; Springel, Volker; Ma, Chung-Pei; Hernquist, Lars; Vogelsberger, Mark; Torrey, Paul A.
    We use the Illustris simulation to study the relative contributions of in situ star formation and stellar accretion to the build-up of galaxies over an unprecedentedly wide range of masses (M* = 109-1012 M⊙), galaxy types, environments, and assembly histories. We find that the ‘two-phase’ picture of galaxy formation predicted by some models is a good approximation only for the most massive galaxies in our simulation – namely, the stellar mass growth of galaxies below a few times 10¹¹ M⊙ is dominated by in situ star formation at all redshifts. The fraction of the total stellar mass of galaxies at z =...

  12. On the assembly of dwarf galaxies in clusters and their efficient formation of globular clusters

    Mistani, Pouria A.; Sales, Laura V.; Pillepich, Annalisa; Sanchez-Janssen, Rubén; Nelson, Dylan; Rodriguez-Gomez, Vicente; Hernquist, Lars; Vogelsberger, Mark; Torrey, Paul A.
    Galaxy clusters contain a large population of low-mass dwarf elliptical galaxies whose exact origin is unclear: their colours, structural properties and kinematics differ substantially from those of dwarf irregulars in the field. We use the Illustris cosmological simulation to study differences in the assembly histories of dwarf galaxies (3 × 10⁸ < M*/M⊙ < 10¹⁰) according to their environment. We find that cluster dwarfs achieve their maximum total and stellar mass on average ∼8 and ∼4.5 Gyr ago (or redshifts z = 1.0 and 0.4, respectively), around the time of infall into the clusters. In contrast, field dwarfs not subjected...

  13. An analysis of the evolving comoving number density of galaxies in hydrodynamical simulations

    Wellons, Sarah; Nelson, Dylan; Rodriguez-Gomez, Vicente; McKinnon, Ryan; Pillepich, Annalisa; Ma, Chung-Pei; Springel, Volker; Hernquist, Lars; Torrey, Paul A.; Leal Machado, Francisco; Griffen, Brendan F.; McKinnon, Ryan Michael; Vogelsberger, Mark
    We present an analysis of the evolving comoving cumulative number density of galaxy populations found in the Illustris simulation. Cumulative number density is commonly used to link galaxy populations across different epochs by assuming that galaxies preserve their number density in time. Our analysis allows us to examine the extent to which this assumption holds in the presence of galaxy mergers or when rank ordering is broken owing to variable stellar growth rates. Our primary results are as follows: (1) the inferred average stellar mass evolution obtained via a constant comoving number density assumption is systematically biased compared to the...

  14. Global turns in US art history

    Nelson, Steven; Jones, Caroline A
    Although globalization feels recent, questions directed at nationalism from a more worldly perspective were already being posed during the Great War. In 1916, for example, US legal scholar Randolph Bourne wrote an essay entitled “Trans-National America,” in which he advocated for a cosmopolitan mixture of cultures rather than the “melting pot” that had long been promoted in the United States (BOURNE, 1916). Across the Atlantic (and within the enemy country), philosopher Franz Rosenzweig was rhapsodizing in Frankfurt about “world-historical spatial concepts” in his 1917 essay “Globus” (ROSENZWEIG, 1984). These prophetic intellectuals had no impact whatsoever on American art history, which...

  15. History, Violence and Collective Memory: Implications for Mental Health in Ecuador

    Capella, M; Jadhav, SS; Moncrieff, J
    National histories of violence shape experiences of suffering and professional responses. In Ecuador, mental health literature addressing this crucial issue is scarce and little debated. In contrast, local psychiatrists and psychologists within the country face contemporary challenges that are deeply rooted in a violent colonial past and the perpetuation of its fundamental ethos. This paper critically reviews relevant literature on collective memory and historical trauma, and focuses on Ecuador as a case study on how to incorporate history into modern mental health challenges. The discussion poses key questions and outlines possible ways for Ecuador to address the link between history and mental health, including insights from countries that...

  16. Pastoralist Settlement and the Anthropogenic Savannah: the archaeo-ecology of Mili Sita, Kenya

    Boles, OJC
    Pastoralism has long been regarded difficult subject matter for archaeology, particularly in eastern Africa. Ephemeral settlements are presumed to leave little physical residue, such that reconstructions of pastoralist ethno-histories have relied on often-vague distributions of material culture. Cultural-stratigraphic approaches are limited in their capacity to explore the lifeways and social dynamics behind material expressions. As a consequence, our knowledge of how herding spread into the region and the historical development of the specialised stock-keeping communities seen today is hindered by a methodological incapacity to address what are arguably the fundamental drivers of pastoralist daily experience: mobility and landscape ecology. This...

  17. A musicalidade africana narra a vida de vita na comédia-musical nha fala do cineasta Flora Gomes

    Oliveira, Jusciele
    O filme Nha fala (2002), uma comédia-musical, do cineasta Flora Gomes, narra parte da história de Vita, uma jovem guineense, que carrega uma maldição familiar, que proíbe que as mulheres de sua família cantem e, caso essa lei seja descumprida, elas morrerão. No entanto, ao viajar para estudar na França e apaixonar-se por Pierre, canta, conhece o sucesso e resolve voltar para a Guiné-Bissau, para realizar o seu próprio funeral. O presente ensaio, centra-se na análise do filme Nha fala, enfocando inicialmente na discussão sobre gêneros cinematográficos e depois na musicalidade africana e, em especial, as músicas que compõem o...

  18. Photometric estimates of stellar masses in high-redshift galaxies

    Berta, S.; Fritz, J.; Franceschini, A.; Bressan, A.; Lonsdale, C.
    We present a new tool for the photometric estimate of stellar masses in distant galaxies. The observed source spectral energy distributions are fitted by combining sets of various simple stellar populations, with different normalizations and different amounts of dust extinction, for a given (Salpeter) IMF. This treatment gives us the best flexibility and robustness when dealing with the widest variety of physical situation for the target galaxies, including inactive spheroidal and active starburst systems. We tested the code on three classes of sources: complete samples of dusty ISO-selected starbursts and of K-band selected ellipticals and S0s in the HDF South,...

  19. Tectonic processes in a surge-type glacier

    Sharp, Martin; Lawson, Wendy; Anderson, Robert S.
    The 1982–1983 surge of Variegated Glacier involved the development, growth and downglacier propagation of a velocity peak associated with rapid basal sliding facilitated by high subglacial water pressures. Passage of the velocity peak through the glacier was preceded by an episode of longitudinal shortening and followed by an episode of elongation. The deformation history of the glacier ice was dependent upon location relative to the surge nucleus and the final position reached by the propagating velocity peak. Ice above the surge nucleus experienced continuous and cumulative elongation; ice below the final position of the velocity peak experienced continuous and cumulative...

  20. The Revolution will not be Grey, Aspen Art Museum, Aspen

    Young, CSR
    The Revolution Will Not Be Gray presents a selection of works that look both backward and forward at the shifting terrain of revolution, protest, and gestures of refusal. Examining the impetus to observe the world in strictly black-and-white terms, the exhibition reveals an intricate set of histories, politics, and identities, reminding us of the inherent power in the human voice. Featuring work by Andrea Bowers, Abraham Cruzvillegas, Claire Fontaine, Sharon Hayes, Iman Issa, Tony Lewis, Glenn Ligon, Carlos Motta, Pedro Reyes, Adam Pendleton, and Carey Young.

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