1,192 research outputs found

    El turismo solidario como instrumento de desarrollo: un estudio de caso para analizar las principales motivaciones de los turistas solidarios

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    Este estudio se centra en el concepto y evolución del turismo solidario así como en las motivaciones del turista que lo realiza. Tras la revisión de la literatura y basado en un estudio cuantitativo de la cartera de clientes de una ONG española especializada en viajes solidarios, se concluye que la interactuación con otras culturas y el enriquecimiento personal son dos de las principales motivaciones de este tipo de viajero. Los resultados del estudio presentan algunas orientaciones para que las comunidades adapten su oferta actual hacia una mayor integración con el viajero

    Microhardness of different resin cement shades inside the root canal

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    Objectives: To compare microhardness along the root canal post space of two resin cements in different shades and a dual-cure resin core material. Study D esign: Root canals of 21 bovine incisors were prepared for post space. Translucent posts (X?Post, Dentsply DeTrey) were luted using one the following resin luting agent: Calibra (Dentsply DeTrey) in Translucent, Medium and Opaque shades, RelyX Unicem (3M ESPE) in Translucent, A2 and A3 shades and the dual-cure resin core material Core?X flow. All materials were applied according to manufacturers? instructions and were all photopolymerized (Bluephase LED unit, Ivoclar Vivadent, 40s). After 24 hours, roots were transversally cut into 9 slices 1 mm thick from the coronal to apical extremes, three corresponding to each root third. Then, VHNs were recorded (100gf, 30 s) on the resin luting materials along the adhesive interface in all sections. Data were analyzed by two- way ANOVA and SNK tests (?=0.05). Results: A significant influence on microhardness of resin luting material in their respective shades (p<0.001), root third (p<0.001) and interactions between them was detected (p<0.001). RelyX Unicem cement showed the highest microhardness values and Calibra the lowest, regardless of the shade selected. All resin luting materials tested exhibited a significantly higher microhardness in the cervical third. Conclusions: Microhardness of resin luting agents tested inside the canal is dependent on material brand and resin cement shade seems to be a less relevant factor. Microhardness decreased along the root canal, regardless of the shade selecte

    Curing effectiveness of resin composites at different exposure times using LED and halogen units

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    Objective: To compare the polymerization effectiveness of two resin composites cured with a quartz tungsten halogen (QTH) lamp or a light emitting diodes (LED) unit. Study design: Filtek Z250 (3M ESPE) and Spectrum TPH (Dentsply DeTrey) resin composites were placed in 9 mm deep and 4 mm wide metallic molds and cured using the QTH light Hilux 200 (Benlioglu) or the LED unit Smartlite IQ (Dentsply DeTrey) for 20 or 40 s (three specimens per group). Measurement of depth of cure was carried out by means of a scraping technique, according to ISO 4049. The microhardness measurements were performed using a calibrated Vickers indenter (100 g load, 30 s) at depths of 0.5, 1.5, 2.5, 3.5, 4.5 and 5.5 mm from the top of the composite in the same specimens. Results were analyzed by ANOVA, Student ́s t and Student-Newman-Keuls tests (p<0.05). Results: Filtek Z250 exhibited higher depth of cure and Vickers microhardness values than Spectrum TPH under each experimental condition evaluated. Depth of cure and microhardness were not affected by the curing light used. However, hardness values were influenced by the interaction between curing light and exposure time. Specimens irradiated for 20 s exhibited higher microhardness values when the LED curing light was used. Exposure time had no influence on the microhardness values for depths from 0.5 to 2.5 mm. At higher depths, irradiation for 40 s produced greater microhardness values. Conclusions: Curing effectiveness of resin composite is not only dependent on the curing light unit. Results vary greatly with composite brand, thickness of the resin composite and the duration of the exposure

    Eating Disorders as New Forms of Addiction

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    Eating disorders (ED) seem to share many characteristics with substance-related disorders (SRD). As very often the two conditions run together, it has been proposed that eating dysfunctions could be understood as behavioral forms of addiction. This has lead to the concept of “food addiction,” a proposed new form of addiction. This chapter reviews recent research focusing on the relationship between ED and SRD. Three specific areas are addressed: (a) animal models that suggest the association between substance dependence and compulsive overeating; (b) epidemiological studies that confirm the comorbidity between ED and SRD; and (c) neuroimaging studies that reveal the existence of modifications in the reward circuits following binge eating and other eating dysfunctions. The data from the different studies can be integrated into a model based on the consideration of “food addiction” as a specific form of behavioral addiction that could be applied at least to a group of patients suffering from eating disorders

    Oscillatory patterns in redox gradient materials through wireless bipolar electrochemistry. The dynamic wave-like case of copper bipolar oxidation

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    Altres ajuts: ICN2 is funded by the CERCA program/Generalitat de Catalunya.Bipolar electrochemistry allows the development of processes in a wireless manner, with reactions occurring at the induced anodes and cathodes of an immersed conducting material in the electrolyte. As a result, a gradient oxidation state may appear along the main axis field on the surface or bulk of the material depending on the type of reaction available at each induced potential. Redox intercalation gradients have been observed, metal anodization, or deposition, and also reactions at the electrolyte in the nearby environment of the poles induced. The complex oxidation of copper and interconversion between phases formed yields in this work an oscillating redox gradient, thanks to the great resistance change when the oxidized phases are formed. Parallel stripes containing mainly CuO, CuO, and Cu(OH) with large resistance are formed perpendicular to the electric field, forming a sequence of secondary dipoles in intermediate Cu stripes, that depends on the external voltage applied, and that oscillates in time at the same spatial coordinates. With longer times, copper solubilizes at the larger induced potential zones, probably as Cu(OH) . A simple finite element electrostatic model defines the complex potential waves induced in the piece. The resulting dynamics offer an example of the complexity of order in unwired conducting materials in wet media, either in catalysis, bioelectrodes, electronics, photovoltaics, or energy storage

    Adipose tissue-derived mesenchymal stem cells as a strategy to improve recovery after stroke

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    Introduction: Based on the positive results observed in experimental animal models, adipose tissue-derived mesenchymal stem cells (AD-MSCs) constitute a promising therapy for stroke treatment. However, several aspects need to be clarified to identify the optimal conditions for successful clinical translation. Areas covered: This review focuses on AD-MSC treatment for ischemic and hemorrhagic stroke in experimental animal models. In addition, we will explore the optimization of treatment conditions including AD-MSC production, administration routes and therapeutic windows for their appropriate use in patients, and we will provide an update on clinical trials on this therapy. Expert opinion: Compared with other cell types, AD-MSCs have been less investigated in stroke studies. Currently, experimental animal models have shown safety and efficacy with this treatment after stroke. Due to several advantages of AD-MSCs, such as their abundance and accessibility, they can be considered a promising strategy for use in patients. However, many questions are still to be resolved regarding their mechanisms of action, immune system modulation and the effects of AD-MSCs on all components of the brain that may be affected after ischemic and hemorrhagic strokesThis project is supported by research grants PS12/01754 (Spanish Ministry of Science) and INVICTUS (RD12/0014/0006) (Spanish Neurovascular Network), and Research Institute Carlos III, Ministry Science and Innovatio

    Search on speech from spoken queries: the Multi-domain International ALBAYZIN 2018 Query-by-Example Spoken Term Detection Evaluation

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    [Abstract] The huge amount of information stored in audio and video repositories makes search on speech (SoS) a priority area nowadays. Within SoS, Query-by-Example Spoken Term Detection (QbE STD) aims to retrieve data from a speech repository given a spoken query. Research on this area is continuously fostered with the organization of QbE STD evaluations. This paper presents a multi-domain internationally open evaluation for QbE STD in Spanish. The evaluation aims at retrieving the speech files that contain the queries, providing their start and end times, and a score that reflects the confidence given to the detection. Three different Spanish speech databases that encompass different domains have been employed in the evaluation: MAVIR database, which comprises a set of talks from workshops; RTVE database, which includes broadcast television (TV) shows; and COREMAH database, which contains 2-people spontaneous speech conversations about different topics. The evaluation has been designed carefully so that several analyses of the main results can be carried out. We present the evaluation itself, the three databases, the evaluation metrics, the systems submitted to the evaluation, the results, and the detailed post-evaluation analyses based on some query properties (within-vocabulary/out-of-vocabulary queries, single-word/multi-word queries, and native/foreign queries). Fusion results of the primary systems submitted to the evaluation are also presented. Three different teams took part in the evaluation, and ten different systems were submitted. The results suggest that the QbE STD task is still in progress, and the performance of these systems is highly sensitive to changes in the data domain. Nevertheless, QbE STD strategies are able to outperform text-based STD in unseen data domains.Centro singular de investigación de Galicia; ED431G/04Universidad del País Vasco; GIU16/68Ministerio de Economía y Competitividad; TEC2015-68172-C2-1-PMinisterio de Ciencia, Innovación y Competitividad; RTI2018-098091-B-I00Xunta de Galicia; ED431G/0

    ALBAYZIN 2018 spoken term detection evaluation: a multi-domain international evaluation in Spanish

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    [Abstract] Search on speech (SoS) is a challenging area due to the huge amount of information stored in audio and video repositories. Spoken term detection (STD) is an SoS-related task aiming to retrieve data from a speech repository given a textual representation of a search term (which can include one or more words). This paper presents a multi-domain internationally open evaluation for STD in Spanish. The evaluation has been designed carefully so that several analyses of the main results can be carried out. The evaluation task aims at retrieving the speech files that contain the terms, providing their start and end times, and a score that reflects the confidence given to the detection. Three different Spanish speech databases that encompass different domains have been employed in the evaluation: the MAVIR database, which comprises a set of talks from workshops; the RTVE database, which includes broadcast news programs; and the COREMAH database, which contains 2-people spontaneous speech conversations about different topics. We present the evaluation itself, the three databases, the evaluation metric, the systems submitted to the evaluation, the results, and detailed post-evaluation analyses based on some term properties (within-vocabulary/out-of-vocabulary terms, single-word/multi-word terms, and native/foreign terms). Fusion results of the primary systems submitted to the evaluation are also presented. Three different research groups took part in the evaluation, and 11 different systems were submitted. The obtained results suggest that the STD task is still in progress and performance is highly sensitive to changes in the data domain.Ministerio de Economía y Competitividad; TIN2015-64282-R,Ministerio de Economía y Competitividad; RTI2018-093336-B-C22Ministerio de Economía y Competitividad; TEC2015-65345-PXunta de Galicia; ED431B 2016/035Xunta de Galicia; GPC ED431B 2019/003Xunta de Galicia; GRC 2014/024Xunta de Galicia; ED431G/01Xunta de Galicia; ED431G/04Agrupación estratéxica consolidada; GIU16/68Ministerio de Economía y Competitividad; TEC2015-68172-C2-1-

    Implementing Pairings at the 192-bit Security Level

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    We implement asymmetric pairings derived from Kachisa-Schaefer-Scott (KSS), Barreto-Naehrig (BN), and Barreto-Lynn-Scott (BLS) elliptic curves at the 192-bit security level. Somewhat surprisingly, we find pairings derived from BLS curves with embedding degree 12 to be the fastest for our serial as well as our parallel implementations. Our serial implementations provide a factor-3 speedup over the previous state-of-the-art, demonstrating that pairing computation at the 192-bit security level is not as expensive as previously thought. We also present a general framework for deriving a Weil-type pairing that is well-suited for computing a single pairing on a multi-processor machine
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