B+→K−π+π+B^+\to K^-\pi^+\pi^+: three-body final state interactions and KπK\pi isospin states

Final state interactions are considered to formulate the $B$ meson decay amplitude for the $K\pi\pi$ channel. The Faddeev decomposition of the Bethe-Salpeter equation is used in order to build a relativistic three-body model within the light-front framework. The S-wave scattering amplitude for the $K\pi$ system is considered in the $1/2$ and $3/2$ isospin channels with the set of inhomogeneous integral equations solved perturbatively. In comparison with previous results for the $D$ meson decay in the same channel, one has to consider the different partonic processes, which build the source amplitudes, and the larger absorption to other decay channels appears, that are important features to be addressed. As in the $D$ decay case, the convergence of the rescattering perturbative series is also achieved with two-loop contributions.Comment: 10 pages, 4 figure

A cultura do cafe no sul de Minas Gerais

Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina. Curso de Agronomia

Color-suppression of non-planar diagrams in bosonic bound states

We study the suppression of non-planar diagrams in a scalar QCD model of a meson system in $3+1$ space-time dimensions due to the inclusion of the color degrees of freedom. As a prototype of the color-singlet meson, we consider a flavor-nonsinglet system consisting of a scalar-quark and a scalar-antiquark with equal masses exchanging a scalar-gluon of a different mass, which is investigated within the framework of the homogeneous Bethe-Salpeter equation. The equation is solved by using the Nakanishi representation for the manifestly covariant bound-state amplitude and its light-front projection. The resulting non-singular integral equation is solved numerically. The damping of the impact of the cross-ladder kernel on the binding energies are studied in detail. The color-suppression of the cross-ladder effects on the light-front wave function and the elastic electromagnetic form factor are also discussed. As our results show, the suppression appears significantly large for $N_c=3$, which supports the use of rainbow-ladder truncations in practical nonperturbative calculations within QCD.Comment: 12 pages, 7 figures. To appear in Physics Letters

Solving the three-body bound-state Bethe-Salpeter equation in Minkowski space

The scalar three-body Bethe-Salpeter equation, with zero-range interaction, is solved in Minkowski space by direct integration of the four-dimensional integral equation. The singularities appearing in the propagators are treated properly by standard analytical and numerical methods, without relying on any ansatz or assumption. The results for the binding energies and transverse amplitudes are compared with the results computed in Euclidean space. A fair agreement between the calculations is found.Comment: 10 pages, 2 figures, version accepted for publication in Phys. Lett.

Amino Acid-Based Material for the Complementary Therapy of Decubitus Ulcers

Chronic wounds, pressure sores, lesions, and infections of microbial origin in bedridden, paralyzed, or malnutrition patients remain the object of study of many researchers. A variety of factors behind the development of these disorders are related to the patient's immune system, making it unable to respond effectively to the treatment of the wound. These factors can be properly controlled, giving particular importance to the ethiology and stage of the wound, as well as the time periods corresponding to the replacement of the dressings. The present research reports a novel foam/soft material, L-Cys-g-PCL, with an application for decubitus/pressure ulcers, especially for wounds with a difficult healing process due to infections and constant oxidation of the soft tissues. During this work, the interactions between S. aureus and L-Cys-g-PCL foam were studied under conditions that simulate decubitus ulcers; namely, pH and exudate. The effects of duration of grafting (1 or 8 h) and pH (7.0 and 8.9) on wettability, surface energy, swelling, and porosity were also evaluated. Results showed an effective microbicidal activity exhibiting an inhibition ratio of 99.73% against S. aureus. This new L-Cys-g-PCL soft material showed saftey to contact skin, ability to be shaped to fill in sunken holes (craters) - pressure ulcers stage III - and to act as a smart material responsive to pH, which can be tailored to develop better swelling properties at alkaline pH where exudates are normally higher, so as to address exudate self-cleaning and prevention of desiccation..info:eu-repo/semantics/publishedVersio

Three-body bound states with zero-range interaction in the Bethe-Salpeter approach

The Bethe-Salpeter equation for three bosons with zero-range interaction is solved for the first time. For comparison the light-front equation is also solved. The input is the two-body scattering length and the outputs are the three-body binding energies, Bethe-Salpeter amplitudes and light-front wave functions. Three different regimes are analyzed: ({\it i}) For weak enough two-body interaction the three-body system is unbound. ({\it ii}) For stronger two-body interaction a three-body bound state appears. It provides an interesting example of a deeply bound Borromean system. ({\it iii}) For even stronger two-body interaction this state becomes unphysical with a negative mass squared. However, another physical (excited) state appears, found previously in light-front calculations. The Bethe-Salpeter approach implicitly incorporates three-body forces of relativistic origin, which are attractive and increase the binding energy.Comment: 13 pages, 7 figure

New garment proposal for prevention of spreading Gram-negative bacteria resistant to carbapenem antibiotic class under hospital settings

Sensitive skin diseases, including atopic dermatitis, skin inflammation and bedsores, leave patients vulnerable under hospital setting. It is important for the development of a hospital gown with ‘‘soft hand’’ properties and at the same time as a protector against nosocomial infections. Klebsiella pneumoniae has developed resistance to antibiotics in the carbapenem antibiotic class, known as carbapenem-resistant K. pneumoniae (CRKP). CRKP is resistant to nearly all antibiotics and can kill up to 50% of infected patients. This work consisted in the development of a washable recycled silk fibroin-based gown covalently linked with an amino acid L-Cysteine(L-Cys), focused on prevention of K. pneumoniae establishment, proliferation and spreading to community, for use under hospital settings. With the growing problem of resistance to antibiotics and few new therapies on the horizon, gowns adsorbed with L-Cys show to function as a barrier to the establishment and proliferation of microorganisms, providing user protection from infectious disease. This gown was knitted at a rectilinear needle loom with a Jersey knit structure. Then it was cross-linked with L-Cys, subjected to laundry, and subsequently characterized by energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, contact angle, free energy of adhesion, scanning electron microscopy and transmission electron microscopy. Results presented a bactericidal effect against K. pneumoniae of 94.92% after three rinses and 88.88% after five washing cycles, with the few adhered bacteria with an altered and compromised morphology.info:eu-repo/semantics/publishedVersio

Aprendizagem híbrida aplicada à educação profissional de redes de computadores

Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2017.Esta tese descreve o processo de ensino-aprendizagem utilizando as metodologias: Aprendizado Baseado em Problemas (ABP) e Aula Invertida (AI) para a disciplina de Comunicação em Redes de Computadores, do curso de Manutenção e Suporte em Informática, do Instituto Federal de Brasília. O desenvolvimento, atitude, desempenho dos estudantes e os resultados obtidos a partir da implementação das metodologias foram analisados e comparados. Participaram da pesquisa 160 estudantes, sendo que as turmas foram compostas, em média, por 14 estudantes. De 2011 a 2012, período em que o Método Tradicional de Ensino estava em uso, 53% dos estudantes que iniciaram e permaneceram na disciplina tinham notas abaixo da média de 6.0 (nota mínima, necessária, para aprovação). Em 2013 e 2014 (primeiro semestre), utilizou-se a metodologia ativa ABP, nesse período o desempenho estudantil melhorou, certa de 81% foram aprovados. Os estudantes desenvolveram habilidades transversais imprescindíveis para o mercado de trabalho, por exemplo: trabalho em equipe, liderança, autoconfiança, autonomia na tomada de decisão. Eles, ainda, conseguiram realizar atividades práticas com melhor desenvoltura, quando comparadas com o ensino tradicional. Porém, muitos estudantes apresentaram dificuldades em selecionar materiais de origem confiável e ainda gastavam muito tempo no processo de seleção desses conteúdos. Isso acontecia, segundo relatos dos estudantes, porque “o tempo era curto e os conteúdos ministrados eram complexos”. Diante dessas dificuldades, uma nova metodologia foi proposta. A partir do segundo semestre de 2014, adotou-se um método Híbrido, que envolveu as metodologias ABP e AI (cada método foi utilizado em momentos distintos durante a disciplina). Cerca de 85% dos estudantes foram aprovados. Problemas relacionados a qualidade de material, utilizados para consulta durante as atividades, foram aperfeiçoados. Dessa maneira, conseguiu-se minimizar as dificuldades enfrentadas pelos estudantes durante o desenvolvimento da metodologia ABP e qualidade dos trabalhos apresentados pelas grupos melhoraram, ou seja, o conteúdo apresentado continha melhor embasamento teórico e as soluções práticas foram realizadas com menos dificuldades por parte dos estudantes. O uso do Sistema de Gerenciamento de Aprendizado (Moodle) e aplicativos populares, como por exemplo: Whatsapp, Facebook Google Apps, serviram de apoio ao professor e estudantes durante as aulas. Devido à seleção de materiais de qualidade, a interação professor/monitor/estudante realizada nas aulas presenciais e a distância, o trabalho em equipe e o envolvimento interdisciplinar, contribuíram para a evolução da disciplina em questão. Os resultados foram analisados a partir da aplicação de questionário e análise qualitativa.This thesis describes the process of teaching and learning by the following methods: Problem Based Learning (PBL), Flipped-Classroom (FC), and Learning Management Systems (LMS) which were implemented in a Data Communication & Computer Network (DCCN) subject, in Computer Maintenance and Support (CMS) at the Federal Institute of Brasília. The attitude, retention and performance of students and the results obtained from the implementation of the methodologies were analyzed and compared and 160 students were enrolled with an average of 14 students per class. In 2011 to 2012, when Traditional Lecture (TL) was adopted, 53% of the initially enrolled students received scores lower than 6.0 (score necessary to be approved in the subject). In 2013 and second semester of 2014 the PBL method was used. During this period, the student’s performance improved to about 81% of the enrolled students achieving a score higher than 6. Learners developed transversal skills essential for the work based industry, eg. teamwork, leadership, self confidence, autonomy in decision-marking. They also managed to carry out practical activities with better resourcefulness compared to the TL method. However, many students had difficulty in selecting from approved sources of material and they spent a lot of time to obtain them. Many related “the time given was inadequate to develop the complicated activities proposed by the teacher”. Confronted with these difficulties we adopted a new blended method (the PBL and FC was used at different times in the CMS subject). By the second semester of 2014 and 2015 the score and quality of presented work had improved and 85% of students were approved in the discipline. Problems related to quality of materials used for reference during the activities also improved. Thus, we minimized the difficulties of the students presented during the PBL methodology. The quality of the activities presented by the teams had better theoretical contents and the practical solutions were performed with less difficulty when compared with other methodologies adopted in this research. The use of Learning Management System (Moodle) and popular applications, such as: Whatsapp, Facebook, Google Apps, helped the teacher and students during classroom and e-learning activities. We believe that the alignment of selected online lectures and student/teacher interactions, whether face-to-face or online tools, teamwork and interdisciplinary aspects, combined with the active learning component led to these improvements. The results and students’ perception were analyzed based on a questionnaire and qualitative analysis