1,770 research outputs found

    Acute Effects of a Fungal Volatile Compound

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    Objective: 3-Methylfuran (3-MF) is a common fungal volatile product with active biologic properties, and previous studies have indicated a contribution to airway disease. The aim of the present study was to assess the acute health effects of this compound in humans. Design: Acute effects were assessed via chamber exposure to (1 mg/m(3)) 3-MF. Participants and measurements: Twenty-nine volunteers provided symptom reports, ocular electromyograms, measurement of eye tear film break-up time, vital staining of the eye, nasal lavage, acoustic rhinometry, transfer tests, and dynamic spirometry. Results: No subjective ratings were significantly increased during exposure. Blinking frequency and the lavage biomarkers myeloperoxidase and lysozyme were significantly increased, and forced vital capacity was significantly decreased during exposure to 3-MF compared with air control. Conclusions and relevance to clinical practice: Acute effects in the eyes, nose, and airways were detected and might be the result of the biologically active properties of 3-MF. Thus, 3-MF may contribute to building-related illness

    Long-range potential fluctuations and 1/f noise in hydrogenated amorphous silicon

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    We present a microscopic theory of the low-frequency voltage noise (known as "1/f" noise) in micrometer-thick films of hydrogenated amorphous silicon. This theory traces the noise back to the long-range fluctuations of the Coulomb potential produced by deep defects, thereby predicting the absolute noise intensity as a function of the distribution of defect activation energies. The predictions of this theory are in very good agreement with our own experiments in terms of both the absolute intensity and the temperature dependence of the noise spectra.Comment: 8 pages, 3 figures, several new parts and one new figure are added, but no conceptual revision

    Study of the p p -> p p pi+ pi- Reaction in the Low-Energy Tail of the Roper Resonance

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    Exclusive measurements of the p p -> p p pi+ pi- reaction have been carried out at Tp = 775 MeV at CELSIUS using the PROMICE/WASA setup. Together with data obtained at lower energy they point to a dominance of the Roper excitation in this process. From the observed interference of its decay routes N* -> N sigma and N* -> Delta pi -> N sigma their energy-dependent relative branching ratio is determined

    The effectiveness of manual stretching in the treatment of plantar heel pain: a systematic review

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    Background: Plantar heel pain is a commonly occurring foot complaint. Stretching is frequently utilised as a treatment, yet a systematic review focusing only on its effectiveness has not been published. This review aimed to assess the effectiveness of stretching on pain and function in people with plantar heel pain. Methods: Medline, EMBASE, CINAHL, AMED, and The Cochrane Library were searched from inception to July 2010. Studies fulfilling the inclusion criteria were independently assessed, and their quality evaluated using the modified PEDro scale. Results: Six studies including 365 symptomatic participants were included. Two compared stretching with a control, one study compared stretching to an alternative intervention, one study compared stretching to both alternative and control interventions, and two compared different stretching techniques and durations. Quality rating on the modified Pedro scale varied from two to eight out of a maximum of ten points. The methodologies and interventions varied significantly between studies, making meta-analysis inappropriate. Most participants improved over the course of the studies, but when stretching was compared to alternative or control interventions, the changes only reached statistical significance in one study that used a combination of calf muscle stretches and plantar fascia stretches in their stretching programme. Another study comparing different stretching techniques, showed a statistically significant reduction in some aspects of pain in favour of plantar fascia stretching over calf stretches in the short term. Conclusions: There were too few studies to assess whether stretching is effective compared to control or other interventions, for either pain or function. However, there is some evidence that plantar fascia stretching may be more effective than Achilles tendon stretching alone in the short-term. Appropriately powered randomised controlled trials, utilizing validated outcome measures, blinded assessors and long-term follow up are needed to assess the efficacy of stretching

    Higher Partial Waves in p+p->p+p+eta near Threshold

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    Exclusive measurements of the production of eta mesons in the p+p->p+p+eta reaction have been carried out at excess energies of 16 and 37 MeV above threshold. The deviations from phase space are dominated by the proton-proton final state interaction and this influences particularly the energy distribution of the eta meson. However, evidence is also presented at the higher energy for the existence of an anisotropy in the angular distributions of the eta meson and also of the final proton-proton pair, probably to be associated with D-waves in this system interfering with the dominant S-wave term. The sign of the eta angular anisotropy suggests that rho-exchange is important for this reaction.Comment: 16 pages, LaTeX2e, 3 EPS Figures, Updated version, Accepted for publication in Phys. Lett.

    Fermi Surface of The One-dimensional Kondo Lattice Model

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    We show a strong indication of the existence of a large Fermi surface in the one-dimensional Kondo lattice model. The characteristic wave vector of the model is found to be kF=(1+ρ)π/2k_F=(1+\rho )\pi /2, ρ\rho being the density of the conduction electrons. This result is at first obtained for a variant of the model that includes an antiferromagnetic Heisenberg interaction JHJ_H between the local moments. It is then directly observed in the conventional Kondo lattice (JH=0)(J_H=0), in the narrow range of Kondo couplings where the long distance properties of the model are numerically accessible.Comment: 11 pages, 6 figure

    Observation of strong final-state effects in pi+ production in pp collisions at 400 MeV

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    Differential cross sections of the reactions ppdπ+pp \to d\pi^+ and pppnπ+pp \to pn\pi^+ have been measured at Tp=400T_p = 400 MeV by detecting the charged ejectiles in the angular range 40ΘLab214^0 \leq \Theta_{Lab} \leq 21^\circ. The deduced total cross sections agree well with those published previously for neighbouring energies. The invariant mass spectra are observed to be strongly affected by Δ\Delta production and NNNN final-state interaction. The data are well described by Monte Carlo simulations including both these effects. The ratio of pppnπ+pp \to pn\pi^+ and ppdπ+pp \to d\pi^+ cross sections also compares favourably to a recent theoretical prediction which suggests a dominance of npnp-production in the relative 3S1^3S_1-state.Comment: 17 pages, 5 figure

    Vertical integration for full outsourcing: growth and internationalization of a portuguese packaging firm

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    Based on a case study of a Portuguese packaging firm, this paper examines how vertical integration of the supplier serves as a vehicle for the full outsourcing of the client firms' needs in a solution that reduces transaction costs, favors specialization, and permits small and mediumsized firms to develop competencies that may be exploited in a wide array of projects. Vertical integration by the supplier (a governance decision) is a strategic response to changes in the sourcing model of the clients. Client-supplier relationships have inter-spatial and inter-temporal value that surpasses spot market exchanges
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