Active split-ring metamaterial slabs for magnetic resonance imaging

In this work, it is analyzed the ability of split-ring metamaterial slabs with zero/high permeability to reject/confine the radiofrequency magnetic field in magnetic resonance imaging systems. Using an homogenization procedure, split-ring slabs have been designed and fabricated to work in a 1.5T system. Active elements consisting of pairs of crossed diodes are inserted in the split-rings. With these elements, the permeability of the slabs can be automatically switched between a unity value when interacting with the strong excitation field of the transmitting body coil, and zero or high values when interacting with the weak field produced by protons in tissue. Experiments are shown for different configurations where these slabs can help to locally increase the signal-to-noise-ratio.Comment: 6 pages, 4 figure

Training in endoscopic mucosal resection and endoscopic submucosal dissection: face, content and expert validity of the live porcine model

Introduction: Endoscopic mucosal resection and endoscopic submucosal dissection are demanding procedures. This study aims to establish face, content and expert validity of the live porcine model in performing endoscopic mucosal resection, endoscopic submucosal dissection, complication management and to assess it as a training tool. Material and methods: Tutors and trainees participating in live porcine model endoscopic mucosal resection and endoscopic submucosal dissection workshops filled out a questionnaire regarding the realism of the model compared to human setting and its role as a learning tool. A 10-point Likert scale was used. Results: Ninety-one endoscopists (13 tutors; 78 trainees) were involved in four workshops. Median global classifications for the realism of the life porcine model ranged between 7.0–8.0 (interquartile range 5.0–9.0). Procedures resembled human cases with a median of 9.0 (8.0–9.0) for oesophageal multiband endoscopic mucosal resection; 8.5 (8.0–9.0) for oesophageal endoscopic submucosal dissection; 9.0 (8.0–10.0) for gastric endoscopic submucosal dissection; and 9.0 (8.5–9.75 and 8.0–9.69) for complication detection and management. The animal model as a learning tool had median scores of 9.0 (7.0–10.0) considering how procedures are performed; 9.0–9.5 (8.0–10.0) for usefulness for beginners; and 9.0–10.0 (5.0–10.0) regarding it a prerequisite. Conclusions: Training in a live porcine model was considered very realistic compared to the human setting and was highly appreciated as a learning tool. This is the first study to establish face, content and expert validity of the live porcine model in performing multiband endoscopic mucosal resection, oesophageal and gastric endoscopic submucosal dissection. The validation of this model provides the rationale to incorporate it into formal teaching programmes.info:eu-repo/semantics/publishedVersio

Nonsingular solutions of Hitchin's equations for noncompact gauge groups

We consider a general ansatz for solving the 2-dimensional Hitchin's equations, which arise as dimensional reduction of the 4-dimensional self-dual Yang-Mills equations, with remarkable integrability properties. We focus on the case when the gauge group G is given by a real form of SL(2,C). For G=SO(2,1), the resulting field equations are shown to reduce to either the Liouville, elliptic sinh-Gordon or elliptic sine-Gordon equations. As opposed to the compact case, given by G=SU(2), the field equations associated with the noncompact group SO(2,1) are shown to have smooth real solutions with nonsingular action densities, which are furthermore localized in some sense. We conclude by discussing some particular solutions, defined on R^2, S^2 and T^2, that come out of this ansatz.Comment: 12 pages, 3 figures. To appear in Nonlinearit

Self-control and problematic use of social networking sites: Examining distress tolerance as a mediator among Argentinian college students

Introduction: Use of Social networking sites (SNSs) is a highly prevalent behavior worldwide and, for some individuals, its use can turn maladaptive. There has been growing interest to identify which variables are associated with problematic use of SNSs. Aim: The present study cross-sectionally examined whether the associations between different features of self-control (i.e., impulsivity-like traits, self-regulation and emotion regulation) indirectly relate to two outcomes of SNSs (hours of use and problematic use) via distress tolerance. Methods: A sample of 509 Argentinean college students (70.3% female; Mean age = 21.15 ± 5.15) completed an online survey. Results: Two significant indirect effects were found: a) higher negative urgency was associated with higher problematic use of SNSs via lower distress tolerance and b) higher self-regulation was associated with lower problematic use of SNSs via higher distress tolerance. Positive urgency, negative urgency and self-regulation had significant direct associations with problematic use of SNSs while neither component of emotion regulation was significantly associated with SNSs outcomes. No significant direct or indirect effects were found between any of the self-control features and time spent using SNSs. Conclusions: The results highlight dysfunctional self-control, particularly emotion-driven impulsivity and low self-regulation, as relevant components of maladaptive SNSs that seem to operate by decreasing the perceived capacity to tolerate negative affect. In this context, interventions targeting the development and improvement of distress tolerance abilities might have a positive impact on problematic use of SNS.Fil: Pilatti, Angelina. Universidad Nacional de Córdoba. Instituto de Investigaciones Psicológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Psicológicas; ArgentinaFil: Bravo, Adrián J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Michelini, Yanina Noelia. Universidad Nacional de Córdoba. Instituto de Investigaciones Psicológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Psicológicas; ArgentinaFil: Aguirre, Paula. Universidad Nacional de Córdoba. Instituto de Investigaciones Psicológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Psicológicas; ArgentinaFil: Pautassi, Ricardo Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentin

Use of big data in the surveillance of veterinary diseases: early detection of tick paralysis in companion animals

Background: Tick paralysis, resultant from envenomation by the scrub-tick Ixodes holocyclus, is a serious threat for small companion animals in the eastern coast of Australia. We hypothesise that surveillance systems that are built on Internet search queries may provide a more timely indication of high-risk periods more effectively than current approaches. Methods: Monthly tick paralysis notifications in dogs and cats across Australia and the states of Queensland (QLD) and New South Wales (NSW) were retrieved from Disease WatchDog surveillance system for the period 2011-2013. Internet search terms related to tick paralysis in small companion animals were identified using Google Correlate, and corresponding search frequency metrics were downloaded from Google Trends. Spearman's rank correlations and time series cross correlations were performed to assess which Google search terms lead or are synchronous with tick paralysis notifications. Results: Metrics data were available for 24 relevant search terms at national level, 16 for QLD and 18 for NSW, and they were all significantly correlated with tick paralysis notifications (P < 0.05). Among those terms, 70.8, 56.3 and 50 % showed strong Spearman's correlations, at national level, for QLD, and for NSW respectively, and cross correlation analyses identified searches which lead notifications at national or state levels. Conclusion: This study demonstrates that Internet search metrics can be used to monitor the occurrence of tick paralysis in companion animals, which would facilitate early detection of high-risk periods for tick paralysis cases. This study constitutes the first application of the rapidly emerging field of Internet-based surveillance to veterinary science

Lipid Oxidation Inhibition in Frozen Farmed Salmon (Oncorhynchus kisutch ): Effect of Packaging

3 pages, 1 table.Coho salmon (Oncorhynchus kisutch) has recently attracted a great interest as a farmed product. This research focuses on its commercialisation as a frozen product. For it, an advanced storage technology combining vacuum and a polyphenolic rich-film was applied for a 9-months storage period (–18°C). The study was addressed to lipid hydrolysis and oxidation changes and to endogenous antioxidant content in salmon muscle. No effect of packaging conditions could be observed on free fatty acid formation. However, vacuum packaging conditions provided a partial inhibition of primary (peroxide) and secondary (anisidine value) lipid oxidation development; this inhibitory effect was accompanied by a lower tocopherol isomers loss. The employment of a film including polyphenolic compounds led to a partial inhibition of α-tocopherol breakdown and to a lower secondary (anisidine value) and tertiary (fluorescent compound formation) lipid oxidation development. A partial inhibitory effect on lipid oxidation development is concluded for the employment of a polyphenolic compound rich-film packaging when applied to farmed coho salmon.This research was carried out in the frame of the Project No. 2006 CL 0034 (2007–2008), granted by the U. Chile-CSIC Cooperation Program. Coho salmon fish was provided by Aquachile SA (Puerto Montt, Chile).Peer reviewe

Application of a behavioral objective evidence of evaluation of the influence of others in the performance in soccer

Se presenta el desarrollo de una prueba objetiva basada en el uso de un dinamómetro manual para analizar la influencia que ejerce la presencia de otras personas significativas, como el entrenador o los compañeros, en jugadores de fútbol infantil, cadete y juvenil de la Comunidad Autónoma de Madrid. Su aplicación permite superar las limitaciones presentadas por las pruebas de autoinforme tradicionales, analizando la validez convergente que tienen los resultados obtenidos con los encontrados en la escala de “Influencia de la evaluación del rendimiento” del cuestionario de características psicológicas relacionadas con el rendimiento deportivo factorizado CPRD-f (Olmedilla, García y Martínez, 2006). Los resultados obtenidos muestran la utilidad del empleo de una técnica objetiva como la planteada en el análisis de la influencia que tienen los otros en el rendimiento individualAn objective test, by using a hand dynamometer is presented in order to analyze the influence of significant people as the coach or the team mates in grip strength performance of young soccer players. Through this objective test was possible to overcome the methodological limitations presented by the traditional self-reported measures. The convergent validity between the dynamometer test results and the values obtained from the “Influence of performance evaluation scale” of the Psychological Characteristics related to Sport Performance factored Questionnaire CPRD-f (Olmedilla, García y Martínez, 2006) was also analyzed. The results showed the usefulness of an objective test as the hand dynamometer to analyze the influential role of significant people on individual performanceApresentamos o desenvolvimento de uma prova objetiva baseada no uso de um dinamômetro manual para analisar a influencia que exerce a presença de outras pessoas significativas, como o treinador ou os companheiros nos jogadores de futebol infantis, cadetes e juniores da Comunidad Autónoma de Madrid. Sua aplicação permite superar as limitações apresentadas pelas provas auto-informes tradicionais, analisando a validez convergente que tem os resultados obtidos com os encontrados na escala de “influencia da avaliação do rendimento” do questionário de características psicológicas relacionadas com o rendimento esportivo fatorizado CPRD-f (Olmedilla, García y Martínez, 2006). Os resultados obtido mostram a utilidade da aplicação técnica objetiva como a proposta na analises da influencia que tem os outros no rendimento individualEsta investigación ha sido parcialmente financiada gracias al proyecto de I+D+I MICINN PSI2011-2700