4,730 research outputs found

    Differences in health symptoms among residents living near illegal dump sites in Los Laureles Canyon, Tijuana, Mexico: a cross sectional survey.

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    Living near landfills is a known health hazard prompting recognition of environmental injustice. The study aim was to compare self-reported symptoms of ill health among residents of four neighborhoods, living in haphazardly constructed settlements surrounded by illegal dumpsites in Tijuana, Mexico. One adult from each of 388 households located in Los Laureles Canyon were interviewed about demographics, health status, and symptoms. Distance from each residence to both the nearest dumpsite and the canyon bottom was assessed. The neighborhoods were selected from locations within the canyon, and varied with respect to proximity to dump sites. Residents of San Bernardo reported significantly higher frequencies of ill-health symptoms than the other neighborhoods, including extreme fatigue (OR 3.01 (95% CI 1.6-5.5)), skin problems/irritations (OR 2.73 (95% CI 1.3-5.9)), stomach discomfort (OR 2.47 (1.3-4.8)), eye irritation/tears (OR 2.02 (1.2-3.6)), and confusion/difficulty concentrating (OR 2.39 (1.2-4.8)). Proximity to dumpsites did not explain these results, that varied only slightly when adjusted for distance to nearest dumpsite or distance to the canyon bottom. Because San Bernardo has no paved roads, we hypothesize that dust and the toxicants it carries is a possible explanation for this difference. Studies are needed to further document this association and sources of toxicants

    Higher Education Leadership and the Internationalization Imaginary: Where Personal Biography Meets the Socio-Historical

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    In this chapter, we explore how higher education institution (HEI) leaders perceive the relationship between their international background and their commitment to and vision for internationalization. Our 10 Canadian HEI participants thought there was a direct link between their international backgrounds and commitment to internationalization. While all spoke of the benefits of internationalization, some viewed internationalization through an ethical, socio-cultural lens whereas others privileged internationalization’s instrumental values. We point to tensions facing some leaders in reconciling their ideal visions of internationalization with neoliberal pressures facing HEIs in a global era. We demonstrate the importance of attending to the inter-relationships between broader socio-historical drivers of internationalization and the personal biographies of those charged with advancing internationalization agendas. Our findings lead us to develop a new theoretical concept, which we term the ‘internationalization imaginary’, to understand the interplay between the individual, local, national and global forces shaping internationalization in higher education

    Transverse Momentum Spectra in Au+Au and d+Au Collisions at sNN\sqrt{s_{NN}}=200 GeV and the Pseudorapidity Dependence of High pT_T Suppression

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    We present spectra of charged hadrons from Au+Au and d+Au collisions at sNN=200\sqrt{s_{NN}}=200 GeV measured with the BRAHMS experiment at RHIC. The spectra for different collision centralities are compared to spectra from p+pˉ{\rm p}+\bar{{\rm p}} collisions at the same energy scaled by the number of binary collisions. The resulting ratios (nuclear modification factors) for central Au+Au collisions at η=0\eta=0 and η=2.2\eta=2.2 evidence a strong suppression in the high pTp_{T} region (>>2 GeV/c). In contrast, the d+Au nuclear modification factor (at η=0\eta=0) exhibits an enhancement of the high pTp_T yields. These measurements indicate a high energy loss of the high pTp_T particles in the medium created in the central Au+Au collisions. The lack of suppression in d+Au collisions makes it unlikely that initial state effects can explain the suppression in the central Au+Au collisions.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let

    Rapidity Dependence of Charged Antiparticle-to-Particle Ratios in Au+Au Collisions at sNN=200\sqrt{s_{NN}}=200 GeV

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    We present ratios of the numbers of charged antiparticles to particles (pions, kaons and protons) in Au + Au collisions at sNN=200\sqrt{s_{NN}}=200 GeV as a function of rapidity in the range yy=0-3. While the particle ratios at midrapidity are approaching unity, the K/K+K^-/K^+ and pˉ/p\bar{p}/p ratios decrease significantly at forward rapidities. An interpretation of the results within the statistical model indicates a reduction of the baryon chemical potential from μB130\mu_B \approx 130MeV at yy=3 to μB25\mu_B \approx 25MeV at yy=0.Comment: 4 pages, 4 figure

    Full-scale fatigue testing of a wind turbine blade in flapwise direction and examining the effect of crack propagation on the blade performance

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    In this paper, the sensitivity of the structural integrity of wind turbine blades to debonding of the shear web from the spar cap was investigated. In this regard, modal analysis, static and fatigue testing were performed on a 45.7 m blade for three states of the blade: (i) as received blade (ii) when a crack of 200 mm was introduced between the web and the spar cap and (iii) when the crack was extended to 1000 mm. Calibration pull-tests for all three states of the blade were performed to obtain the strain-bending moment relationship of the blade according to the estimated target bending moment (BM) which the blade is expected to experience in its service life. The resultant data was used to apply appropriate load in the fatigue tests. The blade natural frequencies in flapwise and edgewise directions over a range of frequency domain were found by modal testing for all three states of the blade. The blade first natural frequency for each state was used for the flapwise fatigue tests. These were performed in accordance with technical specification IEC TS 61400-23. The fatigue results showed that, for a 200 mm crack between the web and spar cap at 9 m from the blade root, the crack did not propagate at 50% of the target BM up to 62,110 cycles. However, when the load was increased to 70% of target BM, some damages were detected on the pressure side of the blade. When the 200 mm crack was extended to 1000 mm, the crack began to propagate when the applied load exceeded 100% of target BM and the blade experienced delaminations, adhesive joint failure, compression failure and sandwich core failure

    Complex Dynamic Systems and Language Education:A Sampling of Current Research – Editorial

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    It has been twenty-five years since second language acquisition/development researchers and practitioners were introduced to chaos/complexity theory and its systems (variously referred to in our field as “complex systems,” complex adaptive systems,” and “complex dynamic systems”) (Larsen-Freeman, 1997). Unsurprisingly, the uptake of the new ideas was nonlinear. When they did attract a growing number of scholars, almost all of the research reports were descriptive—pointing out how language—its evolution, its use, its learning, and its teaching—were all complex, dynamic, nonlinear, emergent, feedback-sensitive, self-organizing, initial condition-sensitive, open, adaptive systems. In addition to these characteristics, because language is comprised of many interacting components and can be characterized by a number of scale-free power laws, such as Zipfian distributions, it indeed qualifies as a complex system

    Effects of processing parameters on dough sheet properties

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    Established and supported under the Australian Government’s Cooperative Research Centre Progra

    Advances in String Theory in Curved Backgrounds: A Synthesis Report

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    A synthetic report of the advances in the study of classical and quantum string dynamics in curved backgrounds is provided, namely: the new feature of multistring solutions; the effect of a cosmological constant and of spacial curvature on classical and quantum strings; classical splitting of fundamental strings;the general string evolution in constant curvature spacetimes;the conformal invariant effects;strings on plane waves, shock waves and spacetime singularities and its spectrum. New developments in string gravity and string cosmology are reported: string driven cosmology and its predictions;the primordial gravitation wave background; non-singular string cosmologies from exact conformal field theories;QFT, string temperature and the string phase of de Sitter space; the string phase of black holes;new dual relation between QFT regimes and string regimes and the 'QFT/String Tango'; new coherent string states and minimal uncertainty principle in string theor

    Copepod carcasses as microbial hot spots for pelagic denitrification

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    Copepods are exposed to a high non-predatory mortality and their decomposing carcasses act as microniches with intensified microbial activity. Sinking carcasses could thereby represent anoxic microenvironment sustaining anaerobic microbial pathways in otherwise oxic water columns. Using non-invasive O-2 imaging, we document that carcasses of Calanus finmarchicus had an anoxic interior even at fully air-saturated ambient O-2 level. The extent of anoxia gradually expanded with decreasing ambient O-2 levels. Concurrent microbial sampling showed the expression of nitrite reductase genes (nirS) in all investigated carcass samples and thereby documented the potential for microbial denitrification in carcasses. The nirS gene was occasionally expressed in live copepods, but not as consistently as in carcasses. Incubations of sinking carcasses in (15)NO3-amended seawater demonstrated denitrification, of which on average 34%+/- 17% (n=28) was sustained by nitrification. However, the activity was highly variable and was strongly dependent on the ambient O-2 levels. While denitrification was present even at air-saturation (302 mol L-1), the average carcass specific activity increased several orders of magnitude to approximate to 1 nmol d(-1) at 20% air-saturation (55 mol O-2 L-1) at an ambient temperature of 7 degrees C. Sinking carcasses of C. finmarchicus therefore represent hotspots of pelagic denitrification, but the quantitative importance as a sink for bioavailable nitrogen is strongly dependent on the ambient O-2 level. The importance of carcass associated denitrification could be highly significant in O-2 depleted environments such as Oxygen Minimum Zones (OMZ)
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