571 research outputs found

    In-vehicle nitrogen dioxide concentrations in road tunnels

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    There is a lack of knowledge regarding in-vehicle concentrations of nitrogen dioxide (NO) during transit through road tunnels in urban environments. Furthermore, previous studies have tended to involve a single vehicle and the range of in-vehicle NO concentrations that vehicle occupants may be exposed to is not well defined. This study describes simultaneous measurements of in-vehicle and outside-vehicle NO concentrations on a route through Sydney, Australia that included several major tunnels, minor tunnels and busy surface roads. Tests were conducted on nine passenger vehicles to assess how vehicle characteristics and ventilation settings affected in-vehicle NO concentrations and the in-vehicle-to-outside vehicle (I/O) concentration ratio. NO was measured directly using a cavity attenuated phase shift (CAPS) technique that gave a high temporal and spatial resolution. In the major tunnels, transit-average in-vehicle NO concentrations were lower than outside-vehicle concentrations for all vehicles with cabin air recirculation either on or off. However, markedly lower I/O ratios were obtained with recirculation on (0.08–0.36), suggesting that vehicle occupants can significantly lower their exposure to NO in tunnels by switching recirculation on. The highest mean I/O ratios for NO were measured in older vehicles (0.35–0.36), which is attributed to older vehicles having higher air exchange rates. The results from this study can be used to inform the design and operation of future road tunnels and modelling of personal exposure to NO

    Performance of rectangular duct attenuators under non-ideal configurations with an unlined 90° bend

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    The acoustic performance of duct attenuators under nonideal conditions is experimentally investigated. The experimental method, a modified variation of the standard ISO 7235:2003 - Laboratory measurement procedures for ducted silencers and air-terminal units, was used to design and test non-ideal configurations that reflect the realities of conditions present in modern building duct systems, comparing static insertion loss between each variant. Since the goal was not to obtain absolute figures, the test was not in strict accordance with the standard. From the measurements, comparisons were made between test data obtained through testing that was done in accordance to the ISO 7235:2003 and data obtained using the modified variation of an ISO test rig. The key differences to a standard test rig were the omission of a cross modal filter and the use of MDF as the duct material. With the limitations of the timber rig understood, complete satisfaction of ISO 7235:2003 requirements was not critical in achieving the project outcome. Hence, the timber test rig was proven to be an appropriate substitute for this research. From the investigation, the inclusion of a 90 degree bend in a duct configuration increases attenuator performance (Static insertion loss). However, it is inconclusive from the result as to whether situating the attenuator before or after the bend may result in the best performance due to the variability measured across the 5 measuring positions along the diagonal of the duct in the measuring station (MS), required by the ISO standard. Factors influencing the variability or Maximum Level Differences (MLD) may be mainly attributed to the anechoic termination (AT) performance, the lack of a modal filter, and cross modal excitation as a result of installing a bend

    Interaction of Alu Polymorphisms and Novel Measures of Discrimination in Association with Blood Pressure in African Americans Living in Tallahassee

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    African Americans are 40% more likely to be afflicted with hypertension in comparison to non-Hispanic, white Americans, resulting in a 30% higher instance of mortality due to cardiovascular disease. There is debate about the relative contributions of genetic and sociocultural risk factors to the racial disparity in hypertension. We assayed three Alu insertion polymorphisms located in the angiotensin-1-converting enzyme (ACE), tissue plasminogen activator (PLAT), and with no-lysine kinase 1 (WNK1) genes. We also estimated West African genetic ancestry and developed novel measures of perceived discrimination to create a biocultural model of blood pressure among African- American adults in Tallahassee, FL (n=158). When tested separately, the ACE Alu non-insertion allele was significantly associated with higher systolic and diastolic blood pressure. In multiple regression analyses, West African genetic ancestry was not associated with blood pressure and reduced the strength of all blood pressure models tested. A gene x environment interaction was identified between the ACE Alu genotype and a new measure of unfair treatment that includes experiences by individuals close to the study participant. Inclusion of the WNK1 Alu genotype further improved this model of blood pressure variation. Our results suggest an association of the ACE and WNK1 genotypes with blood pressure that is consistent with their proposed gene functions. Perceived unfair treatment (to others) shows a threshold effect where an increase in blood pressure is demonstrated at higher values. The interaction between the ACE genotype and unfair treatment highlights the benefits of including both genetic and cultural data to investigate complex disease

    Patient Care in High-Level Containment Care Units: In a Resourced Setting

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    Vasa, A., Boulter, K., Horihan, Cates, D., Piquette, C., Sullivan, J., Johnson, D, & Hewlett, A. (2019). Patient Care in High-Level Containment Care Units. In T. Cieslak, M. Kortepeter, C. Kratochvil, & J. Lawler (Eds.), Nebraska Isolation and Quarantine Manual (pp. 87-101). Lincoln, NE: University of Nebraska Press.https://digitalcommons.unmc.edu/nm_books/1000/thumbnail.jp

    Effects of confinement and surface enhancement on superconductivity

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    Within the Ginzburg-Landau approach a theoretical study is performed of the effects of confinement on the transition to superconductivity for type-I and type-II materials with surface enhancement. The superconducting order parameter is characterized by a negative surface extrapolation length bb. This leads to an increase of the critical field Hc3H_{c3} and to a surface critical temperature in zero field, TcsT_{cs}, which exceeds the bulk TcT_c. When the sample is {\em mesoscopic} of linear size LL the surface induces superconductivity in the interior for TTcsT T_{cs}. In analogy with adsorbed fluids, superconductivity in thin films of type-I materials is akin to {\em capillary condensation} and competes with the interface delocalization or "wetting" transition. The finite-size scaling properties of capillary condensation in superconductors are scrutinized in the limit that the ratio of magnetic penetration depth to superconducting coherence length, Îș≥λ/Ο\kappa \equiv \lambda/\xi , goes to zero, using analytic calculations. While standard finite-size scaling holds for the transition in non-zero magnetic field HH, an anomalous critical-point shift is found for H=0. The increase of TcT_c for H=0 is calculated for mesoscopic films, cylindrical wires, and spherical grains of type-I and type-II materials. Surface curvature is shown to induce a significant increase of TcT_c, characterized by a shift Tc(R)−Tc(∞)T_c(R)-T_c(\infty) inversely proportional to the radius RR.Comment: 37 pages, 5 figures, accepted for PR

    Simulation study of the inhomogeneous Olami-Feder-Christensen model of earthquakes

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    Statistical properties of the inhomogeneous version of the Olami-Feder-Christensen (OFC) model of earthquakes is investigated by numerical simulations. The spatial inhomogeneity is assumed to be dynamical. Critical features found in the original homogeneous OFC model, e.g., the Gutenberg-Richter law and the Omori law are often weakened or suppressed in the presence of inhomogeneity, whereas the characteristic features found in the original homogeneous OFC model, e.g., the near-periodic recurrence of large events and the asperity-like phenomena persist.Comment: Shortened from the first version. To appear in European Physical Journal

    The innate immune sensor Toll-like receptor 2 controls the senescence-associated secretory phenotype

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    Cellular senescence is a stress response program characterized by a robust cell cycle arrest and the induction of a proinflammatory senescence-associated secretory phenotype (SASP) that is triggered through an unknown mechanism. Here, we show that, during oncogene-induced senescence (OIS), the Toll-like receptor 2 (TLR2) and its partner TLR10 are key mediators of senescence in vitro and in murine models. TLR2 promotes cell cycle arrest by regulating the tumor suppressors p53-p21 , p16 , and p15 and regulates the SASP through the induction of the acute-phase serum amyloids A1 and A2 (A-SAAs) that, in turn, function as the damage-associated molecular patterns (DAMPs) signaling through TLR2 in OIS. Last, we found evidence that the cGAS-STING cytosolic DNA sensing pathway primes TLR2 and A-SAAs expression in OIS. In summary, we report that innate immune sensing of senescence-associated DAMPs by TLR2 controls the SASP and reinforces the cell cycle arrest program in OIS

    Empathy at Play:Embodying Posthuman Subjectivities in Gaming

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    In this article, we address the need for a posthuman account of the relationship between the avatar and player. We draw on a particular line of posthumanist theory associated closely with the work of Karen Barad, Rosi Braidotti and N. Katherine Hayles that suggests a constantly permeable, fluid and extended subjectivity, displacing the boundaries between human and other. In doing so, we propose a posthuman concept of empathy in gameplay, and we apply this concept to data from the first author’s 18-month ethnographic field notes of gameplay in the MMORPG World of Warcraft. Exploring these data through our analysis of posthuman empathy, we demonstrate the entanglement of avatar–player, machine–human relationship. We show how empathy allows us to understand this relationship as constantly negotiated and in process, producing visceral reactions in the intra-connected avatar–player subject as well as moments of co-produced in-game action that require ‘affective matching’ between subjective and embodied experiences. We argue that this account of the avatar–player relationship extends research in game culture, providing a horizontal, non-hierarchical discussion of its most necessary interaction

    Wetting films on chemically heterogeneous substrates

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    Based on a microscopic density functional theory we investigate the morphology of thin liquidlike wetting films adsorbed on substrates endowed with well-defined chemical heterogeneities. As paradigmatic cases we focus on a single chemical step and on a single stripe. In view of applications in microfluidics the accuracy of guiding liquids by chemical microchannels is discussed. Finally we give a general prescription of how to investigate theoretically the wetting properties of substrates with arbitrary chemical structures.Comment: 56 pages, RevTeX, 20 Figure

    Late Paleocene Flora of the Northern Alaska Peninsula: The Role of Transberingian Plant Migrations and Climatic Change

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    For the first time, the Late Sagwon Flora is described from the upper beds of the Prince Creek Formation (Upper Paleocene) at the Sagavanirktok River (northern Alaska Peninsula). The flora is dominated by the angiosperm Tiliaephyllum brooksense Moiseeva et Herman sp. nov. and conifer Metasequoia occidentalis (Newb.) Chaney. The Late Sagwon Flora is most similar to the Danian or Danian-Selandian flora from the middle part of the Upper Tsagayan Subformation (Amur Region) and lower part of the Wuyun Formation (Heilongjiang Province, China). This similarity allows us to hypothesize that the genus Tiliaephyllum, which dominated in the Late Tsagayan Flora, migrated via the Bering Land Bridge from southern paleolatitudes of the Far East to high latitudes of the Arctic Pacific, due to the progressively warming climate of the Paleocene. Additional new angiosperm species are described from the Late Sagwon Flora: Archeampelos mullii Moiseeva et Herman sp. nov., Tiliaephyllum brooksense Moiseeva et Herman sp. nov., and Dicotylophyllum sagwonicum Moiseeva et Herman sp. nov
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