286 research outputs found

    Phenomenology of Left-Right Models in the quark sector

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    A natural avenue to extend the Standard Model (SM) is to embed it into a more symmetric framework. Here, I focus in Left-Right (LR) Models, which treat left- and right-handed chiralities on equal footing. Important information about the structure of LR Models comes from meson-mixing observables. Due to the impact of the new contributions to these processes, I consider the calculation of the short-distance QCD effects correcting the LR Model contributions to meson-mixing observables at the Next-to-Leading Order. I then revisit the phenomenology of a simple realization of LR Models, containing doublet scalars, and combine in a global fit electroweak precision observables, direct searches of the new gauge bosons and meson oscillation observables, a task performed within the CKMfitter statistical framework. Finally, I also cover a different issue, namely the modeling of theoretical uncertainties, a class of uncertainties specially important for flavour physics. Different frequentist schemes are compared, and their differences are illustrated with flavour-oriented examples.Comment: PhD thesis. Includes results from hep-ph/1501.05483, hep-ph/1512.00543, hep-ph/1611.04768. E-mail: [email protected]

    Short-distance QCD corrections to K0Kˉ0K^0\bar{K}^0 mixing at next-to-leading order in Left-Right models

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    Left-Right (LR) models are extensions of the Standard Model where left-right symmetry is restored at high energies, and which are strongly constrained by kaon mixing described in the framework of the ΔS=2|\Delta S|=2 effective Hamiltonian. We consider the short-distance QCD corrections to this Hamiltonian both in the Standard Model (SM) and in LR models. The leading logarithms occurring in these short-distance corrections can be resummed within a rigourous Effective Field Theory (EFT) approach integrating out heavy degrees of freedom progressively, or using an approximate simpler method of regions identifying the ranges of loop momentum generating large logarithms in the relevant two-loop diagrams. We compare the two approaches in the SM at next-to-leading order, finding a very good agreement when one scale dominates the problem, but only a fair agreement in the presence of a large logarithm at leading order. We compute the short-distance QCD corrections for LR models at next-to-leading order using the method of regions, and we compare the results with the EFT approach for the WWWW' box with two charm quarks (together with additional diagrams forming a gauge-invariant combination), where a large logarithm occurs already at leading order. We conclude by providing next-to-leading-order estimates for cccc, ctct and tttt boxes in LR models.Comment: Accepted for publication in JHE

    An intelligent tutoring system for operators’ training in power system control centres

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    The activity of Control Center operators is important to guarantee the effective performance of Power Systems. Operators’ actions are crucial to deal with incidents, especially severe faults, like blackouts. In this paper we present an Intelligent Tutoring approach for training Portuguese Control Centre operators in tasks like incident analysis and diagnosis, and service restoration of Power Systems. Intelligent Tutoring System (ITS) approach is used in the training of the operators, taking into account context awareness and the unobtrusive integration in the working environment

    Intelligent training in control centres based on an ambient intelligence paradigm

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    This article describes a new approach in the Intelligent Training of Operators in Power Systems Control Centres, considering the new reality of Renewable Sources, Distributed Generation, and Electricity Markets, under the emerging paradigms of Cyber-Physical Systems and Ambient Intelligence. We propose Intelligent Tutoring Systems as the approach to deal with the intelligent training of operators in these new circumstances

    ESPÉCIES INDICADAS PARA A RECOMPOSIÇÃO DA FLORESTA CILIAR DA SUB-BACIA DO RIO PEIXE-BOI, PARÁ

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    http://dx.doi.org/10.5902/1980509815736This study aims to indicate native species to be used in the restoration of degraded riparian forests in the subwatershed of Peixe-Boi river. All trees and shrubs with diameter at breast height (DBH) > 5 cm were inventoried in ten areas of secondary forest and six areas of igapó forest. The results were analyzed by Principal Component Analysis and the silviculture of the species was assessed by literature review. In Igapó areas 66 species were found; the areas had low richness and low diversity index of Shannon, when compared with data from the secondary forests. The floristic composition was heterogeneous, and the floristic similarity is higher between areas that are closer geographically. In the secondary forests were found 175 species; the areas showed high abundance of individuals, high species richness, diversity and evenness. Secondary forests were separated according to geographic proximity and age, which is directly linked to the successional stage. The PCA analysis established the ecological importance of 29 tree species; however only ten species had enough silvicultural information. Due to a greater ecological importance and viable silvicultural techniques available in the literature, Carapa guianensis, Pachira aquatica, Spondias mombin, Tapirira guianensis and Virola guianensis are the most suitable species to restore the degraded areas, in association with Inga edulis, Jacaranda copaia, Pseudopiptadenia psilostachya, Simarouba amara and Vismia guianensis of the secondary forests, that can be planted in the borders and in the nearby areas of igapó forests.http://dx.doi.org/10.5902/1980509815736Diante da importância ecológica que as florestas ciliares representam para o equilíbrio ambiental, este estudo objetiva indicar espécies nativas para serem usadas na recomposição de florestas ciliares degradadas existentes na sub-bacia do Rio Peixe-Boi. Foram inventariadas todas as árvores e arbustos com diâmetro a 1,30 m do solo > 5 cm em dez áreas de floresta secundária e seis de floresta de igapó. Os dados foram analisados pela Análise de Componentes Principais (ACP) e as espécies avaliadas silviculturalmente através de revisão bibliográfica. As áreas de igapó tiveram baixo índice de riqueza e diversidade de Shannon, quando comparado com os dados das florestas secundárias. A composição florística dos igapós foi bem heterogênea, e há maior similaridade florística entre áreas de maior proximidade geográfica. As florestas secundárias tiveram grande abundância de indivíduos, alta riqueza, diversidade e equabilidade e foram agrupadas em função da proximidade geográfica e da idade, o que está diretamente ligado ao estádio sucessional. A análise ACP estabeleceu a importância ecológica de 29 espécies arbóreas, contudo, foram encontradas informações silviculturais de apenas dez espécies. Por apresentarem grande importância ecológica e técnicas silviculturais viáveis e disponíveis na literatura, as espécies de igapó Carapa guianensis, Pachira aquatica, Spondias mombin, Tapirira guianensis e Virola guianensis são as mais indicadas para a recomposição dessas áreas, em associação com as espécies Inga edulis, Jacaranda copaia, Pseudopiptadenia psilostachya, Simarouba amara e Vismia guianensis de floresta secundária, que podem ser plantadas nas áreas de bordas e adjacentes às florestas de igapó

    Determining organochlorine pesticides in samples of green sea turtles by QuEChERS approach

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    Some Organochlorine Pesticides (OCPs) can pose numerous adverse effects on biota. Marine turtles face numerous threats, in particular those related to anthropogenic activities. Therefore, development and improvement methodologies for monitoring chemical compounds are a relevant task. In this work, we developed a methodology based on the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction for detection of twelve OCPs, by gas chromatography with electron capture detector, in fat and liver samples of green sea turtles. Quantification limits were lower than 5.3 ng g-1; acceptable recovery rates for most compounds; medium matrix effect; matrix-calibration with linearity at the range from 1.0 to 200 ng g-1. This methodology provides contributions for the study of pesticide residues with adverse effects on sea turtle health, important skills for new directions in conservation issues. Alguns Pesticidas organoclorados (OCPs) podem causar numerosos efeitos adversos na biota. As tartarugas marinhas enfrentam diversas ameaças, em especial aquelas relacionadas às atividades antropogênicas, por isso o desenvolvimento de melhorias nos métodos para monitorar compostos químicos são tarefas importantes. Neste trabalho foi desenvolvida uma metodologia baseada na extração QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) para a detecção de doze OCPs, por cromatografia gasosa com captura de elétrons, em amostras de gordura e fígado de tartarugas verdes. Os limites de quantificação ficaram abaixo de 5.3 ng g-1; com taxas de recuperação aceitáveis para a maioria de compostos; efeito matriz médio; calibração da matriz com linearidade variando de 1.0 a 200 ng g-1. Esta metodologia traz contribuições ao estudo de resíduos com efeito adverso na saúde das tartarugas marinhas, sendo importante instrumento para novas direções em temas de conservação.

    Variational quantum eigensolver for causal loop Feynman diagrams and acyclic directed graphs

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    We present a variational quantum eigensolver (VQE) algorithm for the efficient bootstrapping of the causal representation of multiloop Feynman diagrams in the Loop-Tree Duality (LTD) or, equivalently, the selection of acyclic configurations in directed graphs. A loop Hamiltonian based on the adjacency matrix describing a multiloop topology, and whose different energy levels correspond to the number of cycles, is minimized by VQE to identify the causal or acyclic configurations. The algorithm has been adapted to select multiple degenerated minima and thus achieves higher detection rates. A performance comparison with a Grover's based algorithm is discussed in detail. The VQE approach requires, in general, fewer qubits and shorter circuits for its implementation, albeit with lesser success rates.Comment: 32 pages, 7 figures. Improved discussion and success rates of multi-run VQ

    Laser Photobiomodulation and Antimicrobial Photodynamic Therapy in the Treatment of Ovine Otitis

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    Background: Otitis is a severe inflammation of the skin of the auditory canal which can impact animals of all ages. In sheep, this disease can occur in isolated cases or in the entire flock. Laser photobiomodulation can be used in combination with medication or as single therapy and the effects are analgesia, modulation of the inflammatory process, edema reduction, tissue restoration and stimulation of local microcirculation. Antimicrobial photodynamic therapy stands out as a promising alternative to antimicrobial drugs for the treatment of localized infections. This study aimed to report the use of laser phototherapies on a sheep with bacterial otitis.Case: A case of bacterial otitis in a 4-year-old sheep, Dorper, was treated at the Veterinary Hospital of the State University of Santa Cruz. In the anamnesis, the owner reported that the patient presented crusts in the auricular pavilions, and had been medicated with oxytetracycline 20%, administered intramuscularly, for two days and the crusts cleaned with iodine 10%, but the animal did not present clinical improvement. On physical examination, the animal presented constant head swaying, edema of the ears, otalgia, enlarged parotid lymph nodes and ear wounds. No ear discharge was observed, and the initial diagnosis was aural hematoma. The treatment prescribed was laser photobiomodulation for three consecutive days. The lesions were irradiated with a diode laser with a power of 0.1 W, irradiance of 3.5 W/cm2, continuous emission, spot area of 0.028 cm2, wavelength of 808 nm, energy of 4J/point, and fluency/point of 142.8J/cm2, with seven points on the external surface and four points on the internal surface of both ears. Two points were also targeted on the parotid lymph nodes with infrared laser (λ = 808 nm), with energy of 2J/point. On the fourth day of hospitalization, there was a reduction in lesions, decreased edema and absence of pain and on the sixth day of hospitalization, the patient presented mucopurulent otorrhea. The material from the auricular pavilions was collected for cytological examination, confirming the clinical diagnosis of bacterial otitis. Two sessions of Antimicrobial Photodynamic Therapy (aPDT) were performed with an interval of 48 hours, with application of 0.01 % methylene blue, pre-irradiation time of five minutes and irradiation with diode laser with a power of 0.1 W, 660 nm wavelength and 9J/point energy. On the 10 th day after the start of the treatment, there was no pain, healing of ear wounds, and no otorrhea. An additional photobiomodulation session was performed on the unhealed wounds in the auditory canal with red laser (λ = 660nm), on 5 points with an energy of 1J/point. On the 15th day, the left ear was healed and the right ear presented otorrhea, and a further session of aPDT was performed. On the 17th day after starting treatment there was no secretion and all lesions were healed. The patient was subsequently monitored for one month, showing no change or relapse.Discussion: Laser photobiomodulation treatment and antimicrobial photodynamic therapy were efficient in treating bacterial otitis without the use of antibiotics, promoting clinical improvement and patient well-being, making it an alternative to conventional treatment. After searches on the Pubmed, Scielo and Escopus databases using photobiomodulation and antimicrobial photodynamic therapy in sheep otitis as descriptors, this is believed to be the first report on the use of laser phototherapy in sheep otitis. Further studies are needed to establish the dosimetry and frequency of the sessions, as, besides considering animal well-being, this species is an excellent model for human experimentation
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