445 research outputs found

    Efficient identity-based key encapsulation to multiple parties

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    We introduce the concept of identity based key encapsulation to multiple parties (mID-KEM), and define a security model for it. This concept is the identity based analogue of public key KEM to multiple parties. We also analyse possible mID-KEM constructions, and propose an efficient scheme based on bilinear pairings. We prove our scheme secure in the random oracle model under the Gap Bilinear Diffie-Hellman assumption.Fundação para a Ciência e a Tecnologia - SFRH/BPD/20528/2004

    POPULATION DYNAMICS OF PLANT PARASITIC NEMATODES AND THEIR RELATIONSHIPS WITH SOIL PHYSICO-CHEMICAL PARAMETERS DURING THE FALLOW PERIOD AFTER SUGARBEET AND LEADING INTO TOMATO CULTIVATION

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    The main objective of this research was the study of the soil nematode community, and in particular plant parasitic nematodes (PPN), from a field located in Portugal’s southern region, used for sugarbeet production. The study was performed from February to July 2003, covering part of the fallow period previous to tomato cultivation, the alternative crop in the rotation. The end of the fallow period in March and the soil preparation period in May were marked by a significant reduction in the numbers of PPN, whereas their numbers increased on the following tomato crop. The genus Helicotylenchus stood out as the most representative group, forming 90% of all PPN counted each month. The genus Heterodera was relatively abundant in the months following the previous sugarbeet crop, and numbers of the genus Meloidogyne increased during the tomato crop. The correlations between these group and environmental parameters show that, apart from the direct influence of the host, pH, organic matter, temperature and soil moisture significantly influenced nematode abundance and community composition

    Development of new active packaging films coated with natural phenolic compounds to improve the oxidative stability of bee

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    The aim is to develop active packaging films containing natural antioxidants and to evaluate their capacity to enhance the oxidative stability of beef during refrigeration. The antioxidant activity of a natural extract obtained from a brewery residual waste was evaluated and compared with that of a commercial rosemary extract and two synthetic antioxidants (BHT and propyl gallate). Different concentrations of each antioxidant were also added directly to beef samples, resulting in a reduction in lipid oxidation of up to 70–80% relative to the control. Active antioxidant films coated with PVPP-WS extract reduced lipid oxidation by up to 80%, relative to the control, during cold storage. The use of active packaging films containing natural extracts could improve the oxidative stability of meat products and should therefore be of great interest in the food industryThe authors are grateful to the Mahou-San Miguel Group and FUTURAL project (Ingenio Program – CDTI). The authors express their sincere thanks to Ms. Patricia Blanco Carro, Ms. Cristina Casal Romero and Mr. Gonzalo Hermelo Vidal for their excellent technical assistanceS

    On the nature of the (de)coupling of the magnetostructural transition in Er5_5Si4_4

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    In this report, a successful thermodynamical model was employed to understand the structural transition in Er5_5Si4_4, able to explain the decoupling of the magnetic and structural transition. This was achieved by the DFT calculations which were used to determine the energy differences at 0 K, using a LSDA+U approximation. It was found that the M structure as the stable phase at low temperatures as verified experimentally with a ΔF0=\Delta F_0 = -0.262 eV. Finally, it was achieved a variation of Seebeck coefficient (\sim 6 μ\muV) at the structural transition which allow to conclude that the electronic entropy variation is negligible in the transition.Comment: 17 pages, 3 figures, 1 tabl

    Bioassays against pinewood nematode: assessment of a suitable dilution agent and screening for bioactive essential oils

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    Acetone was investigated and found to be an appropriate alternative to Triton X-100 as a solvent of essential oils in bioassays aimed to investigate their effects on pinewood nematode (Bursaphelenchus xylophilus) mortality. Therefore it was used as dilution agent to screen the effectiveness of fifty two essential oils against this pest. Thirteen essential oils were highly effective, resulting in more than 90% pinewood nematode mortality at 2 mg/mL, with six of them resulting in 100% mortality. LC100 values ranged between 0.50 mg/mL and 0.83 mg/mL for the essential oils of Origanum vulgare and Satureja montana, respectively. Essential oils were submitted to gas chromatography and gas chromatography-mass spectrometry analysis and their chemical composition established. Data from essential oils with 100% mortality at 2 mg/mL and other essential oils previously found to have LC100 ≤ 2 mg/mL was combined, their chemical profiles investigated by correspondences analysis plus automatic classification

    A hilbert-style axiomatisation for equational hybrid logic

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    This paper introduces an axiomatisation for equational hybrid logic based on previous axiomatizations and natural deduction systems for propositional and first-order hybrid logic. Its soundness and completeness is discussed. This work is part of a broader research project on the development a general proof calculus for hybrid logics

    Experiencia estética y desarrollo sostenible: Un estudio de caso

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    A partir de la pregunta de cómo pueden contribuir las artes para la comunicación sobre desarrollo sostenible, el estudio hace un análisis sociológico-antropológico de la recepción de una exposición internacional de arte contemporáneo sobre sostenibilidad en Valparaíso, Chile. La experiencia estética del público comprueba que el arte, a través de componentes sensuales y estrategias estéticas que conducen a la reflexión, puede fertilizar la susceptibilidad a cuestiones de desarollo sostenible. Esa potencialidad es capaz de identificar lagunas en la discusión pública local sobre sostenibilidad, pero no es capaz de rellenarlas.Palabras clave: Experiencia estética; sostenibilidad; arte contemporáneo; Valparaíso

    A beam-beam monitoring detector for the MPD experiment at NICA

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    The Multi-Purpose Detector (MPD) is to be installed at the Nuclotron Ion Collider fAcility (NICA) of the Joint Institute for Nuclear Research (JINR). Its main goal is to study the phase diagram of the strongly interacting matter produced in heavy-ion collisions. These studies, while providing insight into the physics of heavy-ion collisions, are relevant for improving our understanding of the evolution of the early Universe and the formation of neutron stars. In order to extend the MPD trigger capabilities, we propose to include a high granularity beam-beam monitoring detector (BE-BE) to provide a level-0 trigger signal with an expected time resolution of 30 ps. This new detector will improve the determination of the reaction plane by the MPD experiment, a key measurement for flow studies that provides physics insight into the early stages of the reaction. In this work, we use simulated Au+Au collisions at NICA energies to show the potential of such a detector to determine the event plane resolution, providing further redundancy to the detectors originally considered for this purpose namely, the Fast Forward Detector (FFD) and the Hadron Calorimeter (HCAL). We also show our results for the time resolution studies of two prototype cells carried out at the T10 beam line at the CERN PS complex.Comment: 16 pages, 12 figures. Updated to published version with added comments and correction

    3D models of pelvic floor muscles developed by manual segmentation to FEM

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    The female pelvic floor is an understudied region of the body from the biomechanical perspective. MRI has been used in the diagnostic evaluation of the pelvic floor dysfunctions. Static images show their morphology while dynamic images show the functional changes that occur on straining and contraction of the pelvic floor. In the present work, MR images contribute to generate 3D solids of pelvic floor muscles through manual segmentation. To study the biomechanical behavior of pelvic floor muscles the Finite Element Method (FEM) would be applied to these 3D solids, contributing to analyze this complex musculature structure. The purpose of this study was to reconstruct tridimensional pelvic floor muscle by manual segmentation and apply FEM. The manual segmentation was made within commercial software. MR images were acquired from the subject supine position, using a 3.0 T system. Field view of the exam was 25×25 cm, 2 mm thick with no gap. The images were acquired in DICOM format, and later converted jpeg format. Twenty consecutive images obtained in the axial plane for each woman were used to construct a 3D model from each of the 8 women. From this 3D reconstruction made through splines in each image, changes in the pubovisceral muscle (a part from the pelvic floor muscles) from the pubis to coccyx were edited. All the pubovisceral muscles edited were exported in step format to the FE analyses software ABAQUS. Finite element meshes were generated for each woman pubovisceral muscle. According to literature soft tissues properties, FE analyses were established to better understand pelvic floor muscles biomechanics. Manual segmentation of the pelvic floor muscles tissues generated very realistic completely different volumetric solids for each woman. It is a very sluggish technique and the nonlinear shape of the pelvic floor makes difficult the utilization of other automatic segmentation
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