190 research outputs found

    The ecology of Atlantic white cedar wetlands: a community profile

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    This monograph on the ecology of Atlantic white cedar wetlands is one of a series of U.S. Fish and Wildlife Service profiles of important freshwater wetland ecosystems of the United States. The purpose of the profile is to describe the extent, components, functioning, history, and treatment of these wetlands. It is intended to provide a useful reference to relevant scientific information and a synthesis of the available literature. The world range of Atlantic white cedar (Chamaecyparis thyoides) is limited to a ribbon of freshwater wetlands within 200 km of the Atlantic and Gulf coasts of the United States, extending from mid-Maine to mid-Florida and Mississippi. Often in inaccessible sites and difficult to traverse, cedar wetlands contain distinctive suites of plant species. Highly valued as commercial timber since the early days of European colonization of the continent, the cedar and its habitat are rapidly disappearing. This profile describes the Atlantic white cedar and the bogs and swamps it dominates or codominates throughout its range, discussing interrelationships with other habitats, putative origins and migration patterns, substrate biogeochemistry, associated plant and animal species (with attention to those that are rare, endangered, or threatened regionally or nationally), and impacts of both natural and anthropogenic disturbance. Research needs for each area are outlined. Chapters are devoted to the practices and problems of harvest and management, and to an examination of a large preserve recently acquired by the USFWS, the Alligator River National Wildlife Refuge in North Carolina

    Investigation of dynamic stresses in detona- tion technical note no. 7

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    Axial and hoop stress calculation in blast loaded thin walled cylindrical pressure vessel

    Grain Boundary Induced Magneto-Far Infrared Resonances in Superconducting YBa2_2Cu3_3O7δ_{7-\delta } Thin Films

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    Spectral features induced by 45^{\circ } in-plane misoriented grains have been observed in the far infrared magneto-transmission of YBa2_2Cu3_3O7δ% _{7-\delta } thin films. Two strong dispersive features are found at 80 and 160 cm1cm^{-1} and a weaker one at 116 cm1cm^{-1}. The data can be well represented by Lorentzian oscillator contributions to the conductivity. Several possible interpretations are discussed. We conclude that the resonances are due to vortex core excitations.Comment: Latex file (14 pages) + 4 Postscript figures, uuencode

    Grief experiences among female American and Arab undergraduate college students

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    © 2015 The Author(s). The purpose of this study was to compare the incidence of grief among American and Arab female undergraduate students, the effects of their grief, and risk of prolonged grief disorder. A total of 471 female undergraduate students, 308 (65.4%) from the United Arab Emirates and 163 (34.6%) from the United States, completed a survey about their grief experiences. Students experiencing a significant loss also completed the Prolonged Grief Disorder Questionnaire. Findings revealed that overall approximately 38.4% (n=181) of all 471 students experienced the loss of a significant person in their lives within the past 24 months; a similar percentage was found in each sub group. Students reported various grief effects with American students experiencing more effects related to sleep, relationships, academics, physical well-being, religion/spirituality, and outlook on life than Arab students. Only a small number (10, 5.52%) of students met the criteria for prolonged grief disorder; however, most students were female Arab students. Limitations of the study and recommendations for future research are provided

    North American wetlands and mosquito control

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    © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in International Journal of Environmental Research and Public Health 9 (2012): 4537-4605, doi:10.3390/ijerph9124537.Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere.Publication of this article was funded in part by the University of Florida Open Access Publishing Fund

    Transformation of in-plane ρ(T)\rho (T) in YBa2Cu3O7δYBa_{2}Cu_{3}O_{7-\delta} at fixed oxygen content

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    This paper reveals the origin of variation in the magnitude and temperature dependence of the normal state resistivity frequently observed in different YBCO single crystal or thin film samples with the same TcT_{c}. We investigated temperature dependence of resistivity in YBa2Cu3O7δYBa_{2}Cu_{3}O_{7-\delta} thin films with 7- δ=6.95\delta = 6.95 and 6.90, which were subjected to annealing in argon at 400-420 K (120140oC120-140^{o}C). Before annealing these films exhibited a non-linear ρab(T)\rho_{ab}(T), with a flattening below 230 K, similar to ρb(T)\rho_{b}(T) and ρab(T)\rho_{ab}(T) observed in untwinned and twinned YBCO crystals, respectively. For all films the annealing causes an increase of resistivity and a transformation of ρab(T)\rho_{ab}(T) from a non-linear dependence towards a more linear one (less flattening). In films with 7- δ=6.90\delta = 6.90 the increase of resistivity is also associated with an increase in TcT_{c}. We proposed the model that provides an explanation of these phenomena in terms of thermally activated redistribution of residual O(5) oxygens in the chain-layer of YBCO. Good agreement between the experimental data for ρab(t,T)\rho_{ab}(t,T), where t is the annealing time, and numerical calculations was obtained.Comment: 8 pages, 9 figures, submitted to PR

    A novel switching delayed PSO algorithm for estimating unknown parameters of lateral flow immunoassay

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    In this paper, the parameter identification problem of the lateral flow immunoassay (LFIA) devices is investigated via a new switching delayed particle swarm optimization (SDPSO) algorithm. By evaluating an evolutionary factor in each generation, the velocity of the particle can adaptively adjust the model according to a Markov chain in the proposed SDPSO method. During the iteration process, the SDPSO can adaptively select the inertia weight, acceleration coefficients, locally best particle pbest and globally best particle gbest in the swarm. It is worth highlighting that the pbest and the gbest can be randomly selected from the corresponding values in the previous iteration. That is, the delayed information of the pbest and the gbest can be exploited to update the particle’s velocity in current iteration according to the evolutionary states. The strategy can not only improve the global search but also enhance the possibility of eventually reaching the gbest. The superiority of the proposed SDPSO is evaluated on a series of unimodal and multimodal benchmark functions. Results demonstrate that the novel SDPSO algorithm outperforms some well-known PSO algorithms in aspects of global search and efficiency of convergence. Finally, the novel SDPSO is successfully exploited to estimate the unknown time-delay parameters of a class of nonlinear state-space LFIA model.This work was supported in part by the Royal Society of the U.K., the Alexander von Humboldt Foundation of Germany, the Natural Science Foundation of China under Grant 61403319, the Fujian Natural Science Foundation under Grant 2015J05131, and the Fujian Provincial Key Laboratory of Eco-Industrial Green Technology

    A Novel Quantum Dots–Based Point of Care Test for Syphilis

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    One-step lateral flow test is recommended as the first line screening of syphilis for primary healthcare settings in developing countries. However, it generally shows low sensitivity. We describe here the development of a novel fluorescent POC (Point Of Care) test method to be used for screening for syphilis. The method was designed to combine the rapidness of lateral flow test and sensitiveness of fluorescent method. 50 syphilis-positive specimens and 50 healthy specimens conformed by Treponema pallidum particle agglutination (TPPA) were tested with Quantum Dot-labeled and colloidal gold-labeled lateral flow test strips, respectively. The results showed that both sensitivity and specificity of the quantum dots–based method reached up to 100% (95% confidence interval [CI], 91–100%), while those of the colloidal gold-based method were 82% (95% CI, 68–91%) and 100% (95% CI, 91–100%), respectively. In addition, the naked-eye detection limit of quantum dot–based method could achieve 2 ng/ml of anti-TP47 polyclonal antibodies purified by affinity chromatography with TP47 antigen, which was tenfold higher than that of colloidal gold–based method. In conclusion, the quantum dots were found to be suitable for labels of lateral flow test strip. Its ease of use, sensitiveness and low cost make it well-suited for population-based on-the-site syphilis screening

    Microwave determination of the quasiparticle scattering time in YBa2Cu3O6.95

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    We report microwave surface resistance (Rs) measurements on two very-high-quality YBa2Cu3O6.95 crystals which exhibit extremely low residual loss at 1.2 K (2-6 μΩ at 2 GHz), a broad, reproducible peak at around 38 K, and a rapid increase in loss, by 4 orders of magnitude, between 80 and 93 K. These data provide one ingredient in the determination of the temperature dependence of the real part of the microwave conductivity, σ1(T), and of the quasiparticle scattering time. The other necessary ingredient is an accurate knowledge of the magnitude and temperature dependence of the London penetration depth, λ(T). This is derived from published data, from microwave data of Anlage, Langley, and co-workers and from, high-quality μSR data. We infer, from a careful analysis of all available data, that λ2(0)/λ2(T) is well approximated by the simple function 1-t2, where t=T/Tc, and that the low-temperature data are incompatible with the existence of an s-wave, BCS-like gap. Combining the Rs and λ(T) data, we find that σ1(T), has a broad peak around 32 K with a value about 20 times that at Tc. Using a generalized two-fluid model, we extract the temperature dependence of the quasiparticle scattering rate which follows an exponential law, exp(T/T0), where T0≊12 K, for T between 15 and 84 K. Such a temperature dependence has previously been observed in measurements of the nuclear spin-lattice relaxation rate. Both the uncertainties in our analysis and the implications for the mechanism of high-temperature superconductivity are discussed

    Fan du Cinéma: Imitation, Europe and The Trip to Italy (2014)

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    his essay considers the role of imitation in Michael Winterbottom’s film The Trip to Italy, with reference to the performances of mimicry by its two protagonists (Steve Coogan and Rob Brydon), but also on the part of the film itself, both as a sequel to The Trip (2010) and through its inter-textual links to earlier works of European and English film, and American-Italian co-production. As I will discuss, this preoccupation with reproduction, situated within a travelogue format, brings into focus a series of related issues concerning the meaning of contemporary film, especially in terms of European cinema in a ‘post-cinematic’ age, as well as the place of cinematic travel in constructing an idea of Europe
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