403 research outputs found

    Civic Center and Cultural Center: The Grouping of Public Buildings in Pittsburgh, Cleveland, and Detroit and the Emergence of the City Monumental in the Modern Metropolis

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    The grouping of public buildings into civic centers and cultural centers became an obsession of American city planners at the turn of the twentieth century. Following European and ancient models, and inspired by the World’s Columbian Exposition in Chicago in 1893 and the McMillan Commission plan for the National Mall in Washington, D.C. in 1901, architects sought to create impressive horizontal ensembles of monumental buildings in urban open spaces such as downtown plazas and quasi-suburban parks in direct opposition to the vertical thrust of commercial skyscrapers. Hitherto viewed largely through narrow the stylistic prism of the City Beautiful vs. the city practical movements, the monumental center (as Jane Jacobs termed it) continued to persist beyond the passing of neoclassicism and the rise of high modernism, thriving as an indispensable motif of futurist aspiration in the era of comprehensive and regional planning, as municipalities sought to counteract the decentralizing pull of the automobile, freeway, air travel and suburban sprawl in postwar America. The administrative civic center and arts and educational cultural center (bolstered by that icon of late urban modernity, the medical center) in turn spawned a new hybrid, the center for the performing arts, exemplified by Lincoln Center and the National Cultural Center (the Kennedy Center for the Performing Arts), as cities sought to integrate convention, sports, and live performance venues into inner-city urban renewal projects. Through the key case studies of Pittsburgh, Cleveland, and Detroit, one-time juggernauts of heavy industry and twenty-first century regions of rust-belt collapse, this study examines the emergence of the ideology of grouping public buildings in urban planning as well as the nineteenth century philology of the keywords civic center and cultural center, terms once actively employed in discourses as diverse as Swiss geography, American anthropology, Social Christianity, the schoolhouse social center movement, and cultural Zionism. It also positions these developments in relation to modern anxieties about the center and its loss, charted by such thinkers as Hans Sedlmayr, Jacques Derrida, and Henri Lefevbre, and considers the contested utopian aspirations of the monumental center as New Jerusalem, Celestial City, and Shining City on a Hill

    Evaluation of ivermectin antiviral activity against avian infectious bronchitis virus using a chicken embryo model

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    Ivermectin is widely used in both animals and humans as an FDA-approved parasiticide. Ivermectin has also been reported to have antiviral activity against several viruses including coronaviruses. There are reports that indicate ivermectin may have some role in diminishing the disease caused by SARS-CoV-2, but the evidence is inconclusive. The objective of this study was to determine if ivermectin was efficacious in inhibiting avian infectious bronchitis virus (IBV, a coronavirus) replication in chicken embryos. Briefly, our approach was to use the Massachusetts vaccine strain of IBV in combination with various doses of ivermectin and then inoculate these preparations into chicken embryos to determine if IBV replication was inhibited. The embryos were examined for IBV lesions and samples of chorioallantoic fluid were collected for IBV RT-PCR analysis. Several trials were performed, and the results of our study indicate that ivermectin did not inhibit IBV replication in chicken embryos

    Air quality in the Industrial Heartland of Alberta, Canada and potential impacts on human health.

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    The "Industrial Heartland" of Alberta is Canada's largest hydrocarbon processing center, with more than 40 major chemical, petrochemical, and oil and gas facilities. Emissions from these industries affect local air quality and human health. This paper characterizes ambient levels of 77 volatile organic compounds (VOCs) in the region using high-precision measurements collected in summer 2010. Remarkably strong enhancements of 43 VOCs were detected, and concentrations in the industrial plumes were often similar to or even higher than levels measured in some of the world's largest cities and industrial regions. For example maximum levels of propene and i-pentane exceeded 100 ppbv, and 1,3-butadiene, a known carcinogen, reached 27 ppbv. Major VOC sources included propene fractionation, diluent separation and bitumen processing. Emissions of the measured VOCs increased the hydroxyl radical reactivity (kOH), a measure of the potential to form downwind ozone, from 3.4 s-1 in background air to 62 s-1 in the most concentrated plumes. The plume value was comparable to polluted megacity values, and acetaldehyde, propene and 1,3-butadiene contributed over half of the plume kOH. Based on a 13-year record (1994-2006) at the county level, the incidence of male hematopoietic cancers (leukemia and non-Hodgkin lymphoma) was higher in communities closest to the Industrial Heartland compared to neighboring counties. While a causal association between these cancers and exposure to industrial emissions cannot be confirmed, this pattern and the elevated VOC levels warrant actions to reduce emissions of known carcinogens, including benzene and 1,3-butadiene

    Leptodora kindtii Population Dynamics in the Island Region of Western Lake Erie before and after the Invasion of the Predacious Cladoceran Bythotrephes longimanus

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    Competition among native and non-native species can cause decreases in population size and production of both species.  The native predaceous crustacean zooplankter Leptodora kindtii shares a similar niche with the invasive Bythotrephes longimanus in Lake Erie.  This niche overlap may contribute to the decline in abundance and production of Leptodora in the western basin of Lake Erie.  Historical (1946) and recent (2006) data were used to determine if the decline in Leptodora abundance and production was associated with the effects of Bythotrephes, which invaded Lake Erie in the mid-1980’s.  Pre-invasion abundances and lengths of L. kindtii were compared with current data (2006).  A change in prey community abundance, composition and dynamics were observed, relative to pre-invasion, with a marked decline in.abundance and size of L. kindtii after the invasion of Bythotrephes. Competition for food and direct predation are two explanations, among others, for the declines observed in L. kindtii size, abundance and production that have occurred since B. longimanus invasion

    Space-Based Range Safety and Future Space Range Applications

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    The National Aeronautics and Space Administration (NASA) Space-Based Telemetry and Range Safety (STARS) study is a multiphase project to demonstrate the performance, flexibility and cost savings that can be realized by using space-based assets for the Range Safety [global positioning system (GPS) metric tracking data, flight termination command and range safety data relay] and Range User (telemetry) functions during vehicle launches and landings. Phase 1 included flight testing S-band Range Safety and Range User hardware in 2003 onboard a high-dynamic aircraft platform at Dryden Flight Research Center (Edwards, California, USA) using the NASA Tracking and Data Relay Satellite System (TDRSS) as the communications link. The current effort, Phase 2, includes hardware and packaging upgrades to the S-band Range Safety system and development of a high data rate Ku-band Range User system. The enhanced Phase 2 Range Safety Unit (RSU) provided real-time video for three days during the historic Global Flyer (Scaled Composites, Mojave, California, USA) flight in March, 2005. Additional Phase 2 testing will include a sounding rocket test of the Range Safety system and aircraft flight testing of both systems. Future testing will include a flight test on a launch vehicle platform. This paper discusses both Range Safety and Range User developments and testing with emphasis on the Range Safety system. The operational concept of a future space-based range is also discussed

    Space-Based Telemetry And Range Safety Flight Demonstration #1

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    The basic ability of STARS to maintain a satellite communications link with TDRSS satellites during dynamic aircraft flights was successfully demonstrated during FD 1. The Range Safety and Range User systems' link margins were measured. The ability to acquire/reacquire and maintain lock between a high-dynamic vehicle and a satellite-based system was demonstrated. The Range Safety system simultaneously received and processed command links from space and ground transmitters and provided near real-time Range Safety telemetry to DFRC, which then sent it in near real time to KSC, GSFC, and WFF for monitoring. The GPS receiver maintained track except during extremely dynamic maneuvers. The Range User system sent data at three different data rates. There were excellent cooperation and support from the different Centers, contractors, and Ranges. A large amount of data was recorded and extensive post-flight analysis was performed. The Range User TDRSS link margin met or exceeded the predicted performance at three different data rates. The Range Safety launch-head link margins generally agreed with the predicted performance. The UPS positions and velocities agreed with those from tracking radar to within about 20 m and a few rn/s. The link margins for the Range Safety TDRSS telemetry link were less than expected. The link margin for one TDRSS command link LPT channel was occasionally much less than the other. Additional post-flight testing has yet to identify the root causes of these results. There were many lessons learned from this first set of test flights. The most important one is that more time and testing are needed for each step to deal with the inevitable problems. It is vital that these lessons be among the primary areas of study that will carry over from FD#1 to FD#2, which is currently scheduled for early FY05 at DFRC and will use a specially designed Ku-band phased array antenna for the Range User system. The next series of flight demonstrations scheduled for late 2004 at DFRC will incorporate many lessons learned from FD#1. A specially designed Ku-band phased array antenna will be used with the Range User system. A test flight on a hypersonic vehicle is planned by the end of 2006

    Multi-instrument comparison and compilation of non-methane organic gas emissions from biomass burning and implications for smoke-derived secondary organic aerosol precursors

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    Multiple trace-gas instruments were deployed during the fourth Fire Lab at Missoula Experiment (FLAME- 4), including the first application of proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOFMS) and comprehensive two-dimensional gas chromatography-time-offlight mass spectrometry (GCĂ—GC-TOFMS) for laboratory biomass burning (BB) measurements. Open-path Fourier transform infrared spectroscopy (OP-FTIR) was also deployed, as well as whole-air sampling (WAS) with onedimensional gas chromatography-mass spectrometry (GCMS) analysis. This combination of instruments provided an unprecedented level of detection and chemical speciation. The chemical composition and emission factors (EFs) determined by these four analytical techniques were compared for four representative fuels. The results demonstrate that the instruments are highly complementary, with each covering some unique and important ranges of compositional space, thus demonstrating the need for multi-instrument approaches to adequately characterize BB smoke emissions. Emission factors for overlapping compounds generally compared within experimental uncertainty, despite some outliers, including monoterpenes. Data from all measurements were synthesized into a single EF database that includes over 500 non-methane organic gases (NMOGs) to provide a comprehensive picture of speciated, gaseous BB emissions. The identified compounds were assessed as a function of volatility; 6-11% of the total NMOG EF was associated with intermediate-volatility organic compounds (IVOCs). These atmospherically relevant compounds historically have been unresolved in BB smoke measurements and thus are largely missing from emission inventories. Additionally, the identified compounds were screened for published secondary organic aerosol (SOA) yields. Of the total reactive carbon (defined as EF scaled by the OH rate constant and carbon number of each compound) in the BB emissions, 55-77% was associated with compounds for which SOA yields are unknown or understudied. The best candidates for future smog chamber experiments were identified based on the relative abundance and ubiquity of the understudied compounds, and they included furfural, 2-methyl furan, 2-furan methanol, and 1,3- cyclopentadiene. Laboratory study of these compounds will facilitate future modeling efforts

    Holography and Eternal Inflation

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    We show that eternal inflation is compatible with holography. In particular, we emphasize that if a region is asymptotically de Sitter in the future, holographic arguments by themselves place no bound on the number of past e-foldings. We also comment briefly on holographic restrictions on the production of baby universes.Comment: 14 pages, 3 figures, revtex4, (v2 relation with work of Banks and Fischler clarified, references added

    901-21 Percutaneous Vascular Surgery: Suture Mediated Percutaneous Closure of Femoral Artery Access Site Following Coronary Intervention

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    A new device (prostarTm, Perclose, Inc.) was developed to close femoral artery access sites percutaneously following coronary interventions in fully anticoagulated patients. The catheter deploys four needles with two pairs of sutures around the hole of femoral artery access sites. The sutures are then tied to close the arteriotomy site mechanically to achieve immediate hemostasis. As a pilot phase, the device was tested in six centers. The device was used immediately following coronary intervention in 91 access sites. Despite an average ACT at the time of the procedure of >300 seconds, immediate complete hemostasis was achieved in 82 sites (90%). The devices were not appropriately positioned in 8 cases and procedures were aborted followed by reinsertion of a sheath or manual compression. Two patients (2.2%) required surgical repair of the femoral artery; one with device mechanical failure and one with bleeding from the initial puncture site in the posterior wall despite successful closure of the sheath site in the front wall. There were no AV fistulae or pseudoaneurysms requiring surgery and no infection, distal embolism or need for blood transfusion.In conclusion, this pilot study suggests that this suture mediated closure device appears to provide safe and effective hemostasis at the femoral access site in fully anticoagulated patients following coronary interventions
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