7,731 research outputs found

    Urbanheart surgery - a logic of design alternatives

    Full text link
    In 1972 Sir Leslie Martin in his essay “The Grid as Generator”, advocated “a strong theoretical basis for [planning and] urban design” (Carolin P, 2000, p4) by methodically shifting design parameters regarding the way “in which buildings [could be] placed on the land” Martin was able to demonstrate how the generation of alternatives could “allow wider scope for decisions and objectives” to be considered and discussed (Carmona M, & Tiesdell S 2007, p81). Operating within a conventional design studio yet drawing of Sir Leslie Martin’s logic, ie developing an informed understanding of a problem by identifying a finite world of design ‘alternatives’, the following paper outlines a studio based program at the School of Architecture and Building, Deakin University, referred to as the ‘UrbanHeart Surgery’. While most atelier-based courses operate largely on an ad-hoc basis where students often work within self imposed competitive isolation, Urbanheart adopts a more open yet structured approach where students work in design collaboratives to generate a matrix of alternative design scenarios. The program actively integrates postgraduate students from Architecture, Urban Design and Planning into a design research culture and allows them to engage in critical discourse by working on strategic design projects in three areas significant to the future development of the state of Victoria: Metropolitan Urbanism, Urbanism on the Periphery and Regional Urbanism

    Study of extremely reddened AGB stars in the Galactic bulge

    Full text link
    Context. Extremely reddened AGB stars lose mass at high rates of >10^-5 Msun/yr. This is the very last stage of AGB evolution, in which stars in the mass range 2.0--4.0 Msun (for solar metallicity) should have been converted to C stars already. The extremely reddened AGB stars in the Galactic bulge are however predominantly O-rich, implying that they might be either low-mass stars or stars at the upper end of the AGB mass range. Aims. To determine the mass range of the most reddened AGB stars in the Galactic bulge. Methods. Using Virtual Observatory tools, we constructed spectral energy distributions of a sample of 37 evolved stars in the Galactic bulge with extremely red IRAS colours. We fitted DUSTY models to the observational data to infer the bolometric fluxes. Applying individual corrections for interstellar extinction and adopting a common distance, we determined luminosities and mass-loss rates, and inferred the progenitor mass range from comparisons with AGB evolutionary models. Results. The observed spectral energy distributions are consistent with a classification as reddened AGB stars, except for two stars, which are proto-planetary nebula candidates. For the AGB stars, we found luminosities in the range 3000--30,000 Lsun and mass-loss rates 10^-5--3x10^-4 Msun/yr. The corresponding mass range is 1.1--6.0 Msun assuming solar metallicity. Conclusions. Contrary to the predictions of the evolutionary models, the luminosity distribution is continuous, with many O-rich AGB stars in the mass range in which they should have been converted into C stars already. We suspect that bulge AGB stars have higher than solar metallicity and therefore may avoid the conversion to C-rich. The presence of low-mass stars in the sample shows that their termination of the AGB evolution also occurs during a final phase of very high mass-loss rate, leading to optically thick circumstellar shells

    Does Terrorism Work?

    Get PDF
    This paper examines whether terrorism is an effective tool to achieve political goals. By exploiting variation in terror attacks over time and across locations in Israel from 1984 to 2006, we show that local terror attacks cause Israelis to be: (i) more willing to grant territorial concessions to the Palestinians; (ii) more willing to accept a Palestinian state; (iii) less likely to identify oneself as being right-wing; and (iv) more likely to have a favorable opinion of Arabs. These effects are especially pronounced for individuals from particular demographic groups which are typically right-wing in their political views. In addition, we show that terror induces Israelis to vote increasingly for right-wing parties. This pattern of results demonstrates that right-wing parties are becoming more accommodating to Palestinian demands for territorial concessions. Hence, this paper shows that terrorism appears to be an effective strategy in terms of shifting the entire Israeli political landscape to the left. These findings may shed light on the causes underlying the spread of global terrorism in the last few decades.

    Linfoma alimentario felino : inmunofenotipo, quimioterapia y evoluciĂłn de 9 casos clĂ­nicos

    Get PDF
    Se describe la clínica, histopatología e inmunofenotipo de 9 gatos cuyo diagnóstico final fue de linfoma alimentario. Los linfomas linfocíticos se trataron con un sólo agente quimioterápico, mientras que en los lifoblásticos se utilizó un protocolo multiagente. La mayoría fueron estadío III, de baja-media intensidad y fenotipo B. Las diferencias obtenidas en la supervivencia de los gatos prodrían ser significativas si la población estudiada fuera mayor

    Recent results from the Pierre Auger Observatory

    Full text link
    The main results from the Auger Observatory are described. A steepening of the spectrum is observed at the highest energies, supporting the expectation that above 4Ă—10194\times 10^{19} eV the cosmic ray energies are significantly degraded by interactions with the CMB photons (the GZK effect). This is further supported by the correlations observed above 6Ă—10196\times 10^{19} eV with the distribution of nearby active galaxies, which also show the potential of Auger to start the era of charged particle astronomy. The lack of observation of photons or neutrinos strongly disfavors top-down models, and these searches may approach in the long term the sensitivity required to test the fluxes expected from the secondaries of the very same GZK process. Bounds on the anisotropies at EeV energies contradict hints from previous experiments that suggested a large excess from regions near the Galactic centre or the presence of a dipolar type modulation of the cosmic ray flux.Comment: 6 p., 8 figs., proceedings of the XXIII International Conference on Neutrino Physics and Astrophysics (Neutrino 08

    Cosmological Magnetic Fields from Gauge-Mediated Supersymmetry-Breaking Models

    Get PDF
    We study the generation of primordial magnetic fields, coherent over cosmologically interesting scales, by gravitational creation of charged scalar particles during the reheating period. We show that magnetic fields consistent with those detected by observation may obtained if the particle mean life \tau_s is in the range 10^{-14} sec \leq \tau_s \leq 10{-7} sec. We apply this mechanism to minimal gauge mediated supersymmetry-breaking models, in the case in which the lightest stau \tilde\tau_1 is the next-to-lightest supersymmetric particle. We show that, for a large range of phenomenologically acceptable values of the supersymmetry-breaking scale \sqrt{F}, the generated primordial magnetic field can be strong enough to seed the galactic dynamo.Comment: 12 pages, Latex. Final version accepted for publication in Phys. Lett.

    Leptogenesis from Supersymmetry Breaking

    Full text link
    We show that soft supersymmetry breaking terms involving the heavy sneutrinos can lead to sneutrino-antisneutrino mixing and to new sources of CP violation, which are present even if a single generation is considered. These terms are naturally present in supersymmetric versions of leptogenesis scenarios, and they induce indirect CP violation in the decays of the heavy sneutrinos, eventually generating a baryon asymmetry. This new contribution can be comparable to or even dominate over the asymmetry produced in traditional leptogenesis scenarios.Comment: 4 pages; An improved discussion of the relevant numerical range of the soft breaking terms (in agreement with hep-ph/0308031

    An infrared study of galactic OH/IR stars. I. An optical/near-IR atlas of the Arecibo sample

    Full text link
    In this paper we present optical and near-infrared finding charts, accurate astrometry (~1") and single-epoch near-infrared photometry for 371 IRAS sources, 96% of those included in the so-called Arecibo sample of OH/IR stars (Eder et al. 1988; Lewis et al. 1990a; Chengalur et al. 1993). The main photometric properties of the stars in the sample are presented and discussed as well as the problems found during the process of identification of the optical/near-infrared counterparts. In addition, we also identify suitable reference stars in each field to be used for differential photometry purposes in the future. We find that 39% of the sources (144 in number) have no optical counterpart, 8 of them being invisible even at near infrared wavelengths. The relative distribution of sources with and without optical counterpart in the IRAS two-colour diagram and their characteristic near infrared colours are interpreted as the consequence of the increasing thickness of their circumstellar shells. Among the objects not detected at near infrared wavelengths four non-variable sources are proposed to be heavily obscured post-AGB stars which have just very recently left the AGB. Eight additional objects with unusually bright and/or blue near-infrared colours are identified as candidate post-AGB stars and/or proto-planetary nebulae.Comment: 28 pages, 9 figures, for associated finding charts see: http://www.edpsciences.org/articles/aa/full/2005/08/aa1709/FINDING_CHARTS/are cibo_index.htm
    • …
    corecore