651 research outputs found

    Rising from of the Ashes: post-war Philippines Architecture

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    The 1945 battle for liberation witnessed the massive decimation of Manila’s urban built-heritage and the irreplaceable treasures of colonial architecture. Despite the seemingly impossible task to resuscitate war ravaged Manila, it rose again. Out of the ashes, modernism provided the opportunity to craft a new architecture for a newly independent nation. Modernism emerged as the period’s architectural symbol of survival and optimism. In a post-colonial cultural milieu, Filipino architects pursued the iconography of national mythology channeled through the pure surfaces and unadorned geometries of modern architecture. They found in modernism a convenient aesthetic modus to denounce the colonial vestiges embodied in the infrastructure of American neoclassicism in pre-war Manila and sought to create new-built environments that conveyed emancipation from the colonial past and celebrate the vernacular forms processed through modernist geometric simplification. Modernism, therefore, was a logical choice, for it provided a progressive image. The Philippines post-independence architecture endeavored to dispense an image that stimulated a national spirit, inspired patriotism, and invoked faith in the unknown future of the national imagination

    Interpreting the time variable RM observed in the core region of the TeV blazar Mrk 421

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    In this work we interpret and discuss the time variable rotation measure (RM) found, for the first time over a 1-yr period, in the core region of a blazar. These results are based on a one-year, multi-frequency (15, 24, and 43 GHz) Very Long Baseline Array (VLBA) monitoring of the TeV blazar Markarian 421 (Mrk 421). We investigate the Faraday screen properties and its location with respect to the jet emitting region. Given that the 43 GHz radio core flux density and the RM time evolution suggest a similar trend, we explore the possible connection between the RM and the accretion rate. Among the various scenarios that we explore, the jet sheath is the most promising candidate for being the main source of Faraday rotation. During the one-year observing period the RM trend shows two sign reversals, which may be qualitatively interpreted within the context of the magnetic tower models. We invoke the presence of two nested helical magnetic fields in the relativistic jet with opposite helicities, whose relative contribution produce the observed RM values. The inner helical field has the poloidal component (BpB_{\rm p}) oriented in the observer's direction and produces a positive RM, while the outer helical field, with BpB_{\rm p} in the opposite direction, produces a negative RM. We assume that the external helical field dominates the contribution to the observed RM, while the internal helical field dominates when a jet perturbation arises during the second observing epoch. Being the intrinsic polarization angle parallel to the jet axis, a pitch angle of the helical magnetic field ϕ≳70∘\phi\gtrsim 70^\circ is required. Additional scenarios are also considered to explain the observed RM sign reversals.Comment: 6 pages, 2 figures. Published on MNRA

    Primary leiomyosarcoma of the pancreas: report of a case treated by local excision and review of the literature

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    First described by Ross in 1951, primary pancreatic leiomyosarcoma is a rare mesenchymal tumour of the pancreas, with nonspecific clinical and radiological features and a poor prognosis, if unresectable

    I AM ADELE BLOCH-BAUER, I AM HESTER PRYNNE

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    I AM ADELE BLOCH-BAUER, I AM HESTER PRYNNE is a compilation of fiction and nonfiction. This cross-genre thesis includes two excerpts from historical novels with female protagonists, and an essay on women’s historical fiction. For the study and creation of female-centered historical fiction I researched and wrote in a wide range of areas, both intellectual and temporal. First, I read and traced the emergence of female-focused American historical fiction that began with Nathaniel Hawthorne’s The Scarlet Letter, and continues today with historical fiction based in fact such as Lily King’s Euphoria and Paula McClain’s The Paris Wife and Circling the Sun. Second, I examined the origin of American feminist thought and literature from Margaret Fuller’s Women of the Nineteenth Century to Virginia Woolf’s A Room of One’s Own, and beyond. Third, I researched fin-de-siècle Jewish Vienna at the dawn of the twentieth century to write and re-envisioned the life of the modern art patron Adele Bloch- Bauer (1881-1925) for the novel Stolen Beauty. Finally, I researched 19th century Concord, Massachusetts and the roots of Transcendentalism, as well as the 1848 Italian revolution, to draft a new novel in which I re-envision the relationship between Margaret Fuller and Nathaniel Hawthorne as it drives the creation of The Scarlet Letter in the years 1840-1850. This new novel is titled I Am Hester Prynne, and a small selection is included herein

    Exploring the connection between radio and GeV-TeV gamma-ray emission in the 1FHL and 2FHL AGN samples

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    The Fermi Large Area Telescope (LAT) revealed that blazars, representing the most extreme radio-loud active galactic nuclei (AGN) population, dominate the census of the gamma-ray sky, and a significant correlation was found between radio and gamma-ray emission in the 0.1-100 GeV energy range. However, the possible connection between radio and very high energy (VHE, E>0.1 TeV) emission still remains elusive, owing to the lack of a homogeneous coverage of the VHE sky. The main goal of this work is to quantify and assess the significance of a possible connection between the radio emission on parsec scale measured by the very long baseline interferometry (VLBI) and GeV-TeV gamma-ray emission in blazars, which is a central issue for understanding the blazar physics and the emission processes. We investigate the radio VLBI and high energy gamma-ray emission by using two large and unbiased AGN samples extracted from the first and second Fermi-LAT catalogs of hard gamma-ray sources detected above 10 GeV (1FHL) and 50 GeV (2FHL). For comparison, we perform the same correlation analysis by using the 0.1-300 GeV gamma-ray energy flux provided by the third Fermi-LAT source catalog. We find that the correlation strength and significance depend on the gamma-ray energy range with a different behavior among the blazar sub-classes. Overall, the radio and gamma-ray emission above 10 GeV turns out to be uncorrelated for the full samples and for all of the blazar sub-classes with the exception of high synchrotron peaked (HSP) objects, which show a strong and significant correlation. On the contrary, when 0.1-300 GeV gamma-ray energies are considered, a strong and significant correlation is found for the full blazar sample as well as for all of the blazar sub-classes. We interpret and explain this correlation behavior within the framework of the blazar spectral energy distribution properties.Comment: 8 pages, 6 figures, 3 tables. Accepted for publication in Astronomy and Astrophysic

    On the radio and GeV-TeV gamma-ray emission connection in Fermi blazars

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    The Fermi-LAT revealed that the census of the gamma-ray sky is dominated by blazars. Looking for a possible connection between radio and gamma-ray emission is a central issue for understanding the blazar physics, and various works were dedicated to this topic. However, while a strong and significant correlation was found between radio and gamma-ray emission in the 0.1-100 GeV energy range, the connection between radio and very high energy (VHE, E>0.1 TeV) emission is still elusive. The main reason is the lack of a homogeneous VHE sky coverage, due to the operational mode of the imaging atmospheric Cherenkov telescopes. With the present work we aim to quantify and assess the significance of the possible connection between high-resolution radio emission, on milliarcsecond scale, and GeV-TeV gamma-ray emission in blazars. For achieving our goal we extract two large and unbiased blazar samples from the 1FHL and 2FHL Fermi catalogs, above 10 GeV and 50 GeV, respectively. To investigate how the correlation evolves as the gamma-ray energy increases, we perform the same analysis by using the 0.1-300 GeV 3FGL gamma-ray energy fluxes. When we consider the 0.1-300 GeV gamma-ray energy range, we find a strong and significant correlation for all of the blazar sub-classes. Conversely, when we consider the gamma-ray emission above 10 GeV the correlation with the radio emission vanishes, with the exception of the blazar sub-class of high synchrotron peaked objects.Comment: 6 pages, 2 figures, 1 table. For the proceedings of the 7th International Fermi Symposiu

    Expression, intracellular targeting and purification of HIV Nef variants in tobacco cells

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    Background Plants may represent excellent alternatives to classical heterologous protein expression systems, especially for the production of biopharmaceuticals and vaccine components. Modern vaccines are becoming increasingly complex, with the incorporation of multiple antigens. Approaches towards developing an HIV vaccine appear to confirm this, with a combination of candidate antigens. Among these, HIV-Nef is considered a promising target for vaccine development because immune responses directed against this viral protein could help to control the initial steps of viral infection and to reduce viral loads and spreading. Two isoforms of Nef protein can be found in cells: a full-length N-terminal myristoylated form (p27, 27 kDa) and a truncated form (p25, 25 kDa). Here we report the expression and purification of HIV Nef from transgenic tobacco. Results We designed constructs to direct the expression of p25 and p27 Nef to either the cytosol or the secretory pathway. We tested these constructs by transient expression in tobacco protoplasts. Cytosolic Nef polypeptides are correctly synthesised and are stable. The same is not true for Nef polypeptides targeted to the secretory pathway by virtue of a signal peptide. We therefore generated transgenic plants expressing cytosolic, full length or truncated Nef. Expression levels were variable, but in some lines they averaged 0.7% of total soluble proteins. Hexahistidine-tagged Nef was easily purified from transgenic tissue in a one-step procedure. Conclusion We have shown that transient expression can help to rapidly determine the best cellular compartment for accumulation of a recombinant protein. We have successfully expressed HIV Nef polypeptides in the cytosol of transgenic tobacco plants. The proteins can easily be purified from transgenic tissue

    Applying 3D modelling technology to traditional craftwork : rapid prototyping in artisanal jewellery making and its impact on the perceived value of jewellery

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    Depuis la révolution industrielle, l’évolution de la technologie bouleverse le monde de la fabrication. Aujourd'hui, de nouvelles technologies telles que le prototypage rapide font une percée dans des domaines comme celui de la fabrication de bijoux, appartenant jadis à l'artisanat et en bouscule les traditions par l'introduction de méthodes plus rapides et plus faciles. Cette recherche vise à répondre aux deux questions suivantes : - ‘En quoi le prototypage rapide influence-t-il la pratique de fabrication de bijoux?’ - ‘En quoi influence-t-il de potentiels acheteurs dans leur appréciation du bijou?’ L' approche consiste en une collecte de données faite au cours de trois entretiens avec différents bijoutiers et une rencontre de deux groupes de discussion composés de consommateurs potentiels. Les résultats ont révélé l’utilité du prototypage rapide pour surmonter un certain nombre d'obstacles inhérents au fait-main, tel que dans sa géométrie, sa commercialisation, et sa finesse de détails. Cependant, il se crée une distance entre la main du bijoutier et l'objet, changeant ainsi la nature de la pratique. Cette technologie est perçue comme un moyen moins authentique car la machine rappelle la production de masse et la possibilité de reproduction en série détruit la notion d’unicité du bijou, en réduisant ainsi sa charge émotionnelle. Cette recherche propose une meilleure compréhension de l'utilisation du prototypage rapide et de ses conséquences dans la fabrication de bijoux. Peut-être ouvrira-t-elle la voie à une recherche visant un meilleur mariage entre cette technique et les méthodes traditionnelles.Since the Industrial Revolution, technology has transformed the world of manufacturing. Nowadays, new technologies, such as rapid prototyping, are breaking through in areas that once belonged exclusively to the domain of handicraft, such as jewellery making, by providing quicker and easier means of fabrication. The methodology of this research uses a mixed approach to answer the two research questions: - ‘How does rapid prototyping technology influence the practice of jewellery making and its outcome? In what way?’ - ‘How does the use of rapid prototyping technology influence potential users appreciation of a piece of jewellery? In what ways?’ During this qualitative research, data were gathered during interviews with three different jewellers as well as with two focus groups composed of potential consumers. The results revealed that the use of RP is useful in overcoming some limits of the handmade techniques regarding geometry, marketability and finesse of details. On the other hand it creates distance between the hand of the jeweller and the created object, thereby denaturalising the practice. The technology was found to be regarded as a less authentic means of making jewellery as compared to hand made: the use of machines recalled mass production and the feature of reproducibility was perceived as something that decreased the emotional potential of a piece of jewellery. This research provides a better understanding of the use of rapid prototyping technology in jewellery making and its implications. It will hopefully inspire the development of ways to better integrate the technology with the manual practice

    High-Sensitivity 86GHz (3.5mm) VLBI Observations of M87: Deep Imaging of the Jet Base at a 10 Schwarzschild-Radius Resolution

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    We report on results from new high-sensitivity, high-resolution 86GHz (3.5 millimeter) observations of the jet base in the nearby radio galaxy M87, obtained by the Very Long Baseline Array in conjunction with the Green Bank Telescope. The resulting image has a dynamic range exceeding 1500 to 1, the highest ever achieved for this jet at this frequency, resolving and imaging a detailed jet formation/collimation structure down to ~10 Schwarzschild radii (Rs). The obtained 86GHz image clearly confirms some important jet features known at lower frequencies, i.e., a wide-opening angle jet base, a limb-brightened intensity profile, a parabola-shape collimation profile and a counter jet. The limb-brightened structure is already well developed at < 0.2mas (< 28Rs, projected) from the core, where the corresponding apparent opening angle becomes as wide as ~100 degrees. The subsequent jet collimation near the black hole evolves in a complicated manner; there is a "constricted" structure at tens Rs from the core, where the jet cross section is locally shrinking. We suggest that an external pressure support from the inner part of radiatively-inefficient accretion flow may be dynamically important in shaping/confining the footprint of the magnetized jet. We also present the first VLBI 86GHz polarimetric experiment for this source, where a highly polarized (~20%) feature is detected near the jet base, indicating the presence of a well-ordered magnetic field. As a by-product, we additionally report a 43/86 GHz polarimetric result for our calibrator 3C 273 suggesting an extreme rotation measure near the core.Comment: Accepted for publication in ApJ. 39 pages, 11 figures, 3 table
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