760 research outputs found

    New methods for stress assessment and monitoring at the workplace

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    The topic of stress is nowadays a very important one, not only in research but on social life in general. People are increasingly aware of this problem and its consequences at several levels: health, social life, work, quality of life, etc. This resulted in a significant increase in the search for devices and applications to measure and manage stress in real-time. Recent technological and scientific evolution fosters this interest with the development of new methods and approaches. In this paper we survey these new methods for stress assessment, focusing especially on those that are suited for the workplace: one of today’s major sources of stress. We contrast them with more traditional methods and compare them between themselves, evaluating nine characteristics. Given the diversity of methods that exist nowadays, this work facilitates the stakeholders’ decision towards which one to use, based on how much their organization values aspects such as privacy, accuracy, cost-effectiveness or intrusivenes

    Easy resolution of severe obstructive kidney injury

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    Chronic constipation is a common diagnosis with a high prevalence in the elderly. Constipation affects the quality of life of sick individuals, bringing several clinical complications.info:eu-repo/semantics/publishedVersio

    Morphology and ecology of Achnanthidium caravelense (Bacillariophyceae), a new species from Portuguese rivers

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    A new benthic freshwater diatom species belonging to the genus Achnanthidium Kütz. has been recorded from several watercourses in the North of Portugal. Achnanthidium caravelense Novais et Ector is described as a new species based on light and scanning electron microscopic observations, as well as on its ecological preferences as reconstructed from field observations. The most characteristic morphological features of this species are the different outline of the raphe valve (narrowly elliptic with linear margins) and the rapheless valve (narrowly elliptic to narrowly rhombic with moderately convex margins), the non-protracted broadly rounded apices and the length/width ratio. Furthermore, the areolae of the single row along the mantle are elongated and are more or less widely open, which is a characteristic discernible in girdle view under light microscopy. The species that A.caravelense resembles most is A. eutrophilum (Lange-Bert.) Lange-Bert.; nevertheless it can be distinguished from the latter by the different raphe valve outline, its higher valve length/width ratio and autecology. A. caravelense is common and abundant in soft waters with low to moderate nutrient content in the North of Portugal

    Properties of magnetic nanodots with perpendicular anisotropy

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    Nanodots with magnetic vortices have many potential applications, such as magnetic memories (VRAMs) and spin transfer nano-oscillators (STNOs). Adding a perpendicular anisotropy term to the magnetic energy of the nanodot it becomes possible to tune the vortex core properties. This can be obtained, e.g., in Co nanodots by varying the thickness of the Co layer in a Co/Pt stack. Here we discuss the spin configuration of circular and elliptical nanodots for different perpendicular anisotropies; we show for nanodisks that micromagnetic simulations and analytical results agree. Increasing the perpendicular anisotropy, the vortex core radii increase, the phase diagrams are modified and new configurations appear; the knowledge of these phase diagrams is relevant for the choice of optimum nanodot dimensions for applications. MFM measurements on Co/Pt multilayers confirm the trend of the vortex core diameters with varying Co layer thicknesses.Comment: 7 pages, 8 figure

    A new common species Achnanthidium caravelense (Bacillariophyceae) discovered in the rivers of North of Portugal

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    Achnanthidium caravelense Novais et Ector is described as a new species based on light and scanning electron microscopic observations, as well as on its ecological preferences as reconstructed from field observations (Novais et al. 2011). The most characteristic morphological features of this species are the different outline of the raphe valve (narrowly elliptic with linear margins) and the rapheless valve (narrowly elliptic to narrowly rhombic with moderately convex margins), the non-protracted broadly rounded apices and the length/width ratio. Furthermore, the areolae of the single row along the mantle are elongated and are more or less widely open, which is a characteristic discernible in girdle view under light microscopy. A comparison with the morphologically similar species Achnanthes standeri Cholnoky, A. taiaensis J. R. Carter, Achnanthidium affine (Grunow) Czarn., A. eutrophilum (Lange-Bert.) Lange-Bert., A. exile (Kütz.) Round et Bukht. and A. minutissimum (Kütz.) Czarn. revealed that the species that A. caravelense resembles most is A. eutrophilum. Nevertheless it can be distinguished from the latter by the different raphe valve outline, its higher valve length/width ratio and ecological preferences. Achnanthidium caravelense is characterized by a set of distinct morphological and ecological features that separate it well from all other similar Achnanthidium species and it is common and abundant in soft water rivers with low to moderate nutrient content in the North of Portugal. There is therefore a rather high probability that this species also occurs in other European countries in rivers with suitable conditions but this Achnanthidium has not yet been recorded due to probable misidentifications with A. eutrophilum or A. minutissimum

    Eosinophilic fasciitis: an atypical presentation of a rare disease

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    Eosinophilic fasciitis, or Shulman's disease, is a rare disease of unknown etiology. It is characterized by peripheral eosinophilia, hypergammaglobulinemia, and high erythrocyte sedimentation rate. The diagnosis is confirmed by a deep biopsy of the skin. The first line of treatment is corticotherapy. We present a rare case of eosinophilic fasciitis in a 27-year-old woman with an atypical presentation with symmetrical peripheral edema and a Groove sign. The patient responded well to treatment with corticosteroids at high doses and, in this context, was associated with hydroxychloroquine and azathioprine. After two and a half years, peripheral eosinophilia had increased, and more of her skin had hardened. At that time, the therapy was modified to include corticoids, methotrexate, and penicillamine. It is of great importance to publicize these cases that allow us to gather experience and better treat our patients.info:eu-repo/semantics/publishedVersio

    Long-time efficacy of the surface code in the presence of a super-Ohmic environment

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    CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPWe study the long-time evolution of a quantum memory coupled to a bosonic environment on which quantum error correction (QEC) is performed using the surface code. The memory's evolution encompasses N QEC cycles, each of them yielding a nonerror syndrome. This assumption makes our analysis independent of the recovery process. We map the expression for the time evolution of the memory onto the partition function of an equivalent statistical-mechanical spin system. In the super-Ohmic dissipation case the long-time evolution of the memory has the same behavior as the time evolution for just one QEC cycle. For this case we find analytical expressions for the critical parameters of the order-disorder phase transition of an equivalent spin system. These critical parameters determine the threshold value for the system-environment coupling below which it is possible to preserve the memory's state.95618CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informação2014/26356-9D.A.L.-D. acknowledges CNPq for financial support. A.O.C. and E.N. wish to thank CNPq and FAPESP through the initiative INCT-IQ. This work was supported in part by FAPESP Grant No. 2014/26356-9 and NSF Grant No. CCF-1117241

    Hamiltonian Formulation of Quantum Error Correction and Correlated Noise: The Effects Of Syndrome Extraction in the Long Time Limit

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    We analyze the long time behavior of a quantum computer running a quantum error correction (QEC) code in the presence of a correlated environment. Starting from a Hamiltonian formulation of realistic noise models, and assuming that QEC is indeed possible, we find formal expressions for the probability of a faulty path and the residual decoherence encoded in the reduced density matrix. Systems with non-zero gate times (``long gates'') are included in our analysis by using an upper bound on the noise. In order to introduce the local error probability for a qubit, we assume that propagation of signals through the environment is slower than the QEC period (hypercube assumption). This allows an explicit calculation in the case of a generalized spin-boson model and a quantum frustration model. The key result is a dimensional criterion: If the correlations decay sufficiently fast, the system evolves toward a stochastic error model for which the threshold theorem of fault-tolerant quantum computation has been proven. On the other hand, if the correlations decay slowly, the traditional proof of this threshold theorem does not hold. This dimensional criterion bears many similarities to criteria that occur in the theory of quantum phase transitions.Comment: 19 pages, 5 figures. Includes response to arXiv:quant-ph/0702050. New title and an additional exampl

    Effect of the particle size range of construction and demolition waste on the fresh and hardened-state properties of fly ash-based geopolymer mortars with total replacement of sand

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    This study seeks the valorization of industrial residues (fly ash and construction and demolition waste (CDW)) through the production of geopolymer mortars. The effect of the sand substitution by CDW and the influence of the particle size range of CDW fine aggregates on the fresh and hardened properties of the mortars were evaluated. Geopolymer mortars were produced using biomass fly ash waste and metakaolin as a binder, CDW as fine aggregates, and an alkali solution of sodium silicate and sodium hydroxide as activator. The geopolymer mortars were characterized in fresh state by the flow table test and in the hardened state through chemical, physical/microstructural analyzes. The mortars produced with CDW showed lower flowability when compared to the ones prepared with sand. The compressive and flexural strength of hardened mortars, respectively, obtained with residues were higher when compared to sand: 40 MPa and 8.5 MPa with CDW, against 23 MPa and 3.1 MPa for sand-based samples. It was observed that mortars developed with recycled aggregate and natural aggregate present similar chemical and mineralogical compositions. The superior results obtained in the mechanical properties of mortars produced with CDW are related to the recycled aggregate-geopolymer paste interface.publishe
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