On the Graceful Game

A graceful labeling of a graph $G$ with $m$ edges consists of labeling the vertices of $G$ with distinct integers from $0$ to $m$ such that, when each edge is assigned as induced label the absolute difference of the labels of its endpoints, all induced edge labels are distinct. Rosa established two well known conjectures: all trees are graceful (1966) and all triangular cacti are graceful (1988). In order to contribute to both conjectures we study graceful labelings in the context of graph games. The Graceful game was introduced by Tuza in 2017 as a two-players game on a connected graph in which the players Alice and Bob take turns labeling the vertices with distinct integers from 0 to $m$. Alice's goal is to gracefully label the graph as Bob's goal is to prevent it from happening. In this work, we study winning strategies for Alice and Bob in complete graphs, paths, cycles, complete bipartite graphs, caterpillars, prisms, wheels, helms, webs, gear graphs, hypercubes and some powers of paths

Quando A Coisa Comum Flutua No Mistério

Sem resumo26

Morfometría e inundaciones urbanas en la cuenca del Río Jaguaribe, Salvador-BA

El objetivo de esta investigación fue analizar los índices morfométricos y sus correlaciones con los episodios de inundaciones en la cuenca del río Jaguaribe. El paisaje en la cuenca del río se ve modificado por la urbanización que dio lugar a la impermeabilización de los suelos y la alteración de los cauces de los ríos. El uso de técnicas de geoprocesamiento combinado con el análisis de varios trabajos técnicos sobre el tema dio como resultado el Mapa de la Red de Drenaje. Los estudios en este mapa asociados con el uso de metodologías de cálculo indicaron que la morfometría contribuiría al rápido flujo de agua debido a la forma alargada de la cuenca. Sin embargo, con los intensos cambios antropogénicos, BHRJ actualmente tiene una fuerte propensión a las inundaciones urbanas.The aim of this research was to analyze the morphometric indices and their correlations with the episodes of floods in the Jaguaribe River basin. The landscape in the river basin is modified by the urbanization that resulted in the waterproofing of soils and the alteration of river channels. The use of geoprocessing techniques combined with the analysis of several technical works on the subject resulted in the Drainage Network Map. The studies in this map associated with the use of calculation methodologies indicated that morphometry would contribute to the rapid flow of water due to the elongated shape of the basin. However, with the intense anthropogenic changes, BHRJ currently has a strong propensity for urban floodsO objetivo desta pesquisa foi analisar os índices morfométricos e suas correlações com os episódios de enchentes na bacia hidrográfica do Rio Jaguaribe. A paisagem na bacia hidrográfica encontra-se modificada pela urbanização que resultou na impermeabilização dos solos e na alteração dos canais fluviais. A utilização das técnicas de geoprocessamento aliadas à análise de diversos trabalhos técnicos sobre o tema resultaram no Mapa da Rede de Drenagem. Os estudos no referido mapa associado ao emprego de metodologias de cálculo, indicaram que a morfometria contribuiria para o rápido escoamento das águas devido o formato alongado da bacia. Porém, com as intensas modificações antropogênicas a BHRJ detém atualmente forte propensão às enchentes urbanas

PMV as a thermal evaluation method for air-conditioned spaces in hot climates: a systematic review

The homogeneity of the subjects that were studied to produce the PMV model developed by Fanger and the evolution of the physical environment have an impact on the usability of the model. Many studies show that the PMV model does not represent the real thermal sensations of the occupants of the analyzed building. The purpose of this review is to identify and group the studies that show some discrepancy between the PMV and the opinions of the subjects concerning modern climatized field environments in hot climates around the world. The PRISMA statement was used to recover and analyze the articles, and 23 studies were selected for this review. The majority of the articles indicated that the PMV model is not suited to evaluate this kind of environment

COMÉRCIO JUSTO INTERNACIONAL: O CASO DO SUCO DE LARANJA ENTRE O BRASIL E A FRANÇA

This paper is a preliminary analysis of the governance structure of the faire trade of orange juice between Brazil and France. Fair trade is an organizational field composed of complex organizational networks that maintain relations of mutual dependence and share the same values system. As fair trade is a subject that has received relatively little study and presents many particularities, an exploratory study was considered appropriate. Primary and secondary data were collected. In the case of the trade of orange juice between Brazil and France, two commercial networks were identified. The integrated network is constituted by professionals who specialize in fair trade, while the certified network includes more conventional commercial organizations, such as supermarkets. However, although they adopt different functioning mechanisms, in the case of orange juice the importers in the integrated network have integrated themselves into the certified network. In this way, they meet the requirements of the certified network and follow its rules for importing Brazilian orange juice. After analyzing the intrinsic characteristics of the product, the asset specificity, the frequency and the uncertainty of the transactions, the governance structure observed was the hybrid arrangement, in which long-term contracts are used to coordinate relations.transaction costs, governance structures, networks, fair trade, orange juice., Agribusiness, Agricultural Finance, Industrial Organization,

High spatial resolution analysis of Pb and U isotopes for geochronology by laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS)

A determinação de idades através do decaimento dos isótopos radioativos 235U e 238U para os isótopos radiogênicos 207Pb e 206Pb, respectivamente, utilizando o mineral zircão (ZrSiO4), é amplamente aplicada para decifrar processos geológicos. Um novo método tem sido desenvolvido nos últimos anos, a ablação a laser multi-coletor espectrometria de massas com plasma indutivamente acoplado (LA-MC-ICP-MS), superando o laborioso trabalho anteriormente necessário em outros métodos, na preparação de amostras, e permite obtenção de razões isotópicas com alta resolução espacial de micrômetros. O presente estudo descreve os procedimentos analíticos e os métodos usados na redução de dados que estão sendo aplicados no Laboratório de Geocronologia da Universidade de Brasília. Explora-se a precisão e exatidão do método através da análise de três padrões internacionais de zircão. Observa-se uma precisão entre 1,9 a 3,7% (2σ desvio padrão) e uma exatidão de 0,6 a 3,8% (2σ desvio padrão) para as razões isotópicas de Pb e U dos padrões. Também foram obtidas idades pelo método LA-ICP-MS de duas amostras de zircões naturais, que já foram datadas anteriormente por outros métodos analíticos. A comparação dos resultados mostra uma boa conformidade das idades obtidas, dentro dos limites de erro.Os dados demonstram o grande potencial do método analítico para análises isotópicas rápidas, precisas e exatas de U-Pb, numa escala de micrômetros. ________________________________________________________________________________________ ABSTRACTAge determinations using the 235U and 238U radioactive decay series to the daughter isotopes 207Pb and 206Pb, respectively, using the mineral zircon (ZrSiO4), are widely used to decipher geological processes. A new method developed in the last couple of years, the laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS), overcomes previous laborious sample preparation, and yields isotopic ratios and age data with a high spatial resolution of ten of microns. The present study describes the analytical set-up and data reduction process as presently applied at the Laboratory for Geochronology of the University of Brasília. It explores the precision and accuracy of the method by cross-analysing three international zircon standards. We arrive at a precision of 1.9 to 3.7% (2σ SD) and an accuracy of 0.6 to 3.8% (2σ SD) for and U isotopic ratios of the standards. We also apply the method to two natural zircon samples, which have previously been dated by other analytical methods. A comparison of the results show a good conformity of the age data,being whitin the error limits. The data demonstrate the great analytical potential of the method for rapid, precise and accurate U-Pb isotopic analyses on the micron scale

Combined U-Pb and Lu-Hf isotope analyses by laser ablation MC-ICP-MS : methodology and applications

O sistema isotópico Lutécio-Hafnio representa uma das ferramentas mais recentes e poderosas para estudos isotópicos e geocronológicos. Análises combinadas in situ de U-Pb e Lu-Hf sobre zircão pelo LA-MC-ICP-MS permitem caracterizar isotopicamente o magma onde ele cristalizou, fornecendo valiosas informações para estudos de proveniência de sedimento e de evolução crustal. Nesse trabalho descrevemos a sistemática de Lu-Hf pelo LA-MC-ICP-MS implantada no laboratório de Geocronologia da Universidade de Brasília e reportamos os resultados obtidos de repetidas análises de três padrões de zircão: GJ-1 = 0.282022 ± 11 (2SD, n=56), Temora 2 = 0.282693 ± 14 (2SD, n=25) and UQ-Z = 0.282127 ± 33 (2SD, n=11). Foi também caracterizada arazão isotópica 176Hf/177Hf(0.282352 ± 22, 2SD, n=14) de um zircão usado como padrão interno do laboratório. Como aplicação geológica, analisamos dois zircões complexos selecionados a partir de uma amostra de migmatito da Província de Borborema, NE do Brasil. Sobre a base dos dados U-Pb e Lu-Hf foram identificados em ambos os zircões dois eventos de cristalização. Um evento mais antigo de 2.05 Ga nos núcleos herdados, representa um evento magmático Paleoproterozoico bem conhecido na Província Borborema. Um segundo evento de ~ 575 Ma, reconhecido nas bordas, representa um evento magmático-metamórfico Neoproterozóico (Brasiliano). ________________________________________________________________________________________ ABSTRACTThe Lutetium-Hafnium isotopic system represents one of the most innovative and powerful tools for geochronology and isotopic studies. Combined U-Pb and Lu-Hf in situ analyses on zircon by LA-MC-ICP-MS permit to characterize isotopically the host magma from which it crystallized furnishing significant information for sediment provenance and crustal evolution studies. In this paper e describe the Lu-Hf systematic by LA-MC-ICP-MS developed in the laboratory of Geochronology of the University of Brasilia and report the results obtained by repeated analyses of 176Hf/177Hf isotopic ratio of three zircon standards: GJ-1 = 0.282022 ± 11 (n=56), Temora 2 = 0.282693 ± 14 (n=25) and UQZ = 0.282127 ± 33 (n=11). The 176Hf/177Hf ratio (0.282352 ± 22, n=14) of gem quality zircon used as in-house standard have been also characterized. As a geological application, we analyzed two complex zircons selected from a migmatitic rocks from the Borborema Province, NE Brazil. On the basis of U-Pb and Lu-Hf data, two main crystallization events have been identified in both studied zircons. An older event at ca. 2.05 Ga recognized in the inherited cores represents a well-characterized paleoproterozoic magmatic event that affected the whole Borborema Province. A second crystallization event at ~ 575 Ma, recognized at the rims, represents a Neoproterozoic (Brazilian) high grade metamorphic-magmatic event

Dental surgery in patients on oral anticoagulation therapy

Em razão do crescimento do número de indivíduos submetidos à terapêutica anticoagulante também nos consultórios odontológicos, realizamos um levantamento retrospectivo de prontuários de pacientes anticoagulados com derivados cumarínicos e uma revisão sobre os protocolos de atendimento, a fim de procurar estabelecer diretrizes para um tratamento cirúrgico-odontológico adequado e seguro. A avaliação do paciente com relação ao seu nível de anticoagulação através do Índice Normatizado Internacional (INR) ou Tempo de Protrombina (TP) e a classificação da amplitude do trauma cirúrgico são fatores importantes a serem avaliados antes do procedimento cirúrgico. Nosso levantamento mostrou que, em 47 cirurgias, sem alteração da medicação sistêmica, apenas um caso apresentou hemorragia pós-operatória, controlada por manobras de hemostasia local. Desse modo, observamos que, dentre os vários protocolos propostos na literatura, a manutenção da terapia anticoagulante, com a utilização de hemostáticos locais se necessário, parece o mais adequado à maioria dos casos cirúrgicos ambulatoriais.In the daily medical practice there has been an increase in the use of anticoagulant drugs; as a consequence, dental offices are receiving more individuals under this therapy. Nowadays dental surgeons need a broader knowledge of hemostasis and associated therapies in order to offer the best possible assistance. This article presents a retrospective study based on the clinical records of anticoagulated patients using dicoumarin who underwent dental surgical procedures. Twenty-six patients were submitted to forty-seven minor dental surgical procedures without any change to their doses of anticoagulants. Laboratorial evaluations of PT (pro-thrombin time) based on the INR (International Normalized Ratio) were performed for all patients. The results showed that only one patient reported postoperative bleeding which was controlled by local compression. Based on the results of this study and a brief review of publications, the authors suggest that the most adequate conduct for most patients is to maintain anticoagulation therapy and the complementary use of local hemostasis when necessary