The shading sign: is it exclusive of endometriomas?

To investigate if the shading sign is an exclusive MRI feature of endometriomas or endometrioid tumors, and to analyze its different patterns. Three hundred and fourty six women with adnexal masses who underwent 1.5/3-T MRI were included in this retrospective, board-approved study. The shading sign was found in 56 patients, but five cases were excluded due to lack of imaging follow-up or histological correlation. The final sample included 51 women. The type of tumor and the pattern of shading were recorded for each case. Thirty endometriomas and five endometrioid carcinomas were found. The remaining 16 cases corresponded to other benign and malignant tumors. The overall sensitivity, specificity, positive predictive value, and negative predictive value were 73%, 93%, 59%, and 96%, respectively. Restricting the analysis to cystic lesions without solid or fat component, sensitivity, specificity, positive predictive value, and negative predictive value were 73%, 96%, 94%, and 80%. Five shading patterns were identified: layering (15.7%), liquid-liquid level (11.8%), homogenous (45.1%), heterogeneous (11.8%), and focal/multifocal shading within a complex mass (19.6%). No significant correlation was found between these patterns and the type of tumor. The shading sign is not exclusive of endometriomas or endometrioid tumors. Homogenous shading was the most prevalent pattern in endometriomas and half of the cases with focal/multifocal shading within a complex mass were endometrioid carcinomas.info:eu-repo/semantics/publishedVersio

O impacto dos efeitos da memória de longo termo na linearizabilidade de amplificadores de potência baseados em AlGaN/GaN HEMT

AlGaN/GaN High Electron Mobility Transistor (HEMT)s are among the preferred options for radio-frequency power amplification in cellular base station transmitters and radar applications. However, despite their promising outlook, the pervasiveness of trapping effects makes them resilient to conventional digital predistortion schemes, which not only decrease their current range of applications but could also preclude their integration in future small cells and multiple-input multiple-output architectures where simpler predistortion schemes are mandatory. So, this PhD thesis aims at developing a meaningful link between the device physics and the linearizability of the AlGaN/GaN HEMT-based Power Amplifier (PA). In order to bridge this gap, this thesis begins with a clear explanation for the mechanisms governing the dominant source of trapping effects in standard AlGaN/GaN HEMTs, namely buffer traps. Based on this knowledge, we explain why the best known physically-supported trapping models, used to represent these devices, are insufficient and present a possible improvement to what we consider to be the most accurate model, supported by Technology Computer-Aided Design (TCAD) simulations. This has also been corroborated through a novel double-pulse technique able to describe experimentally both the capture and emission transients in a wide temporal span under guaranteed isothermal conditions. The measured stretched capture transients validated our understanding of the process while the temperature dependence of the emission profiles confirmed buffer traps as the dominant source of trapping effects. Finally, through both simulations and experimental results, we elaborate here the relationship between the emission time constant and the achievable linearity of GaN HEMT-based PAs, showing that the worst-case scenario happens when the emission time constant is on the order of the time between consecutive envelope peaks above a certain amplitude threshold. This is the case in which we observed a more pronounced hysteresis on the gain and phase-shift characteristics, and so, a stronger impact of the memory effects. The main outcome of this thesis suggests that the biggest linearizability concern in standard AlGaN/GaN HEMT-based PAs lies on the large emission time constants of buffer traps.AlGaN/GaN HEMTs estão entre as opções preferidas para amplificação de potência de radiofrequência em transmissores de estacão base celular e aplicações de radar. No entanto, apesar de sua perspetiva promissora, a influência dos efeitos de defeitos com níveis profundos torna-os imunes aos esquemas convencionais de pre-distorção digital. Assim, esta tese de doutoramento visa desenvolver uma ligação significativa entre a física do dispositivo e a linearização de amplificadores de potência baseados em Al- GaN/GaN HEMTs. Por forma a preencher esta lacuna, esta tese começa com uma explicação clara dos mecanismos que governam a fonte dominante de efeitos de defeitos com níveis profundos em AlGaN/GaN HEMTs standard, especificamente defeitos no buffer. Com base neste conhecimento, são aparentadas as falhas dos modelos físicos mais conhecidos de defeitos de nível profundo usados para representar estes dispositivos, assim como uma possível melhoria suportada em simulações de TCAD. Isto é também corroborado por uma nova técnica de duplo-pulso capaz de descrever experimentalmente os transientes de captura e emissão num amplo intervalo temporal sob condições isotérmicas. Os transientes de captura medidos validam a nossa compreensão do processo, enquanto que a dependência da temperatura nos perfis de emissão confirmou os defeitos no buffer como a fonte dominante de efeitos de defeitos com níveis profundos. Por fim, através de simulações e resultados experimentais, elabora-se aqui a relação entre a constante de tempo de emissão e a linearizabilidade dos amplificadores baseados em AlGaN/GaN HEMT, mostrando que o pior cenário acontece quando a constante de tempo de emissão é da mesma ordem do tempo entre picos consecutivos da envolvente acima de um certo limiar de amplitude. Este é o caso para o qual se observa uma histerese mais pronunciada nas características de ganho e fase e, consequentemente, um impacto mais forte dos efeitos de memória. O resultado principal desta tese sugere que a maior preocupação na linearização de amplificadores baseados em AlGaN/GaN HEMTs standard está nas grandes constantes de tempo de emissão dos defeitos no buffer.Programa Doutoral em Engenharia Eletrotécnic

The Brazilian Soccer Fans Economic Fidelity

Soccer in Brazil is not just a sport being what they call national passion influencing families behaviors according a research of MOA Researches In the last years has been seen in Brazil a feature that the clubs are increasing single game tickets prices influencing their supporters to buy a kind of full season ticket According Moreira 2013 the Coritiba Foot Ball Club has raised the single game tickets prices in at least 261 and on the other hand the minimum wage of Brazil has increased 183 From this information the club practically forces the supporters to purchase any _full season plan A problem with the implementation of the full season plan in Brazil is the feature that some soccer clubs are not the owners of the stadiums where they play That brings restrictions of practices related to full season plans whereas there is a limitation in the exploitation of the physical spaces of a stadium The main point for clubs to strengthen their full season plans is the fans customer loyalty The clubs should keep them paying for the full season plans on time Azevedo 2013 affirm

Land use change and ecosystem services: linking social and ecological systems across time

In light of the projected climate change for the coming decades, there is an urgent need for multifunctional landscapes that are capable to provide a diversity of ecosystem services. This requires a better understanding of social and ecological factors that influence how these landscapes are managed and how this, in turn, influences the provision of ecosystem services. Land Use Land Cover (LULC) changes are one of the main factors that lead to spatiotemporal changes of ecosystems services. As such, the identification of the main socioeconomic drivers of LULC can give important insights about the drivers of ecosystem services. However, the analysis of ecosystem services in a context of socio-ecological systems is still underdeveloped. Brazil has witnessed intense changes in LULC in the last five centuries, which may have influenced the provision of ecosystem services at local, regional and global scales. In the southeast mountain area of the Atlantic Forest biome, the Zona da Mata de Minas Gerais is characterized by a heterogeneous landscape mosaic composed of pasture and coffee fields intermingled with forest fragments, which are predominantly inhabited and managed by family farmers. The Zona da Mata is considered a complex socio-ecological system and is an interesting case to study the spatio-temporal provision of ecosystem services. In Chapter 2, I assessed the LULC changes from 1986 to 2015 and their main socioeconomic drivers. By combining data obtained from satellite images, workshops and secondary data, I showed that forest and coffee areas increased, and pasture decreased. These changes were associated with government measures to protect the environment, financial support of family farmers, migration to cities and the agroecological movement. A scenarios analysis of contrasting socio-economic narratives indicated that sustainable measures taken by the government to protect the environment and support family farmers with financial credit will lead to increase forest and coffee areas in the Green Road scenario. In contrast, the socioeconomic development in the Fossil Fuel scenario, which projects a decline in environmental protection and focuses on rapid economic development, there will be a decline in forest areas. In Chapter 3, I explored the spatial variation of ecosystem services from 1986 to 2015 and the impacts of LULC changes on ecosystem services provision levels and their interactions. To map the spatio variation of ecosystem services, I used the LULC maps from 1986 and 2015 (Chapter 2) and the InVEST model. This analysis indicated that the conversion of forest to pasture has strong negative impacts on soil erosion control and water flow regulation, manifesting mostly as trade-offs and dis-synergies between ecosystem services. In Chapter 4, I investigated the separate effects of LULC changes and climate on water dynamics from 1990 to 2015, and explored scenarios of LULC change and climate change for 2045. For this purpose, I used the SWAT model and climate data combined with historical and future LULC maps developed in Chapter 2. I found that the variation in climate variables was the main factor for the observed increase in the river streamflow in the study period and that forest can buffer extreme precipitation events. The exploration of future scenarios indicated that the increase in forest cover under the Green Road scenario is expected to decrease the surface runoff water and increase evapotranspiration as compared to the Fossil Fuel scenario, mitigating the impacts of soil erosion and climatic extremes in the region. Projected changes in precipitation and temperature are expected to have negative impacts for agriculture in the future. In Chapter 5, I assessed the impact of climate change on the suitability of Coffea arabica production in the study region and the potential of agroforestry systems to mitigate these impacts. For this, I combined the species distribution model MaxEnt with current and future climate projections. Agroforestry system have the potential to reduce air temperatures under the canopy of trees. I explored the effect of the altered the microclimate in agroforestry systems on the suitability for coffee production by adjusting future climate data to reflect conditions in agroforestry systems. I found that the area suitability for coffee production from the current monoculture coffee systems will decline by 60% under the projected climatic changes. However, the implementation of coffee agroforestry systems can mitigate these negative impacts of climatic change and maintain 75% of the area suitable for coffee production in 2050. Combining social and ecological systems in an interdisciplinary framework, generated insights in the relationships between climate and LULC change, and how this influences several ecosystem services. This framework connects different research fields and allows different stakeholders to work together to find effective ways to work towards multifunctional landscapes that promote the sustainable use of ecosystem services

Driver’s behavior classification in vehicular communication networks for commercial vehicles

Vehicles are becoming more intelligent and connected due to the demand for faster, efficient, and safer transportation. For this transformation, it was necessary to increase the amount of data transferred between electronic modules in the vehicular network since it is vital for an intelligent system’s decision-making process. Hundreds of messages travel all the time in a vehicle, creating opportunities for analysis and development of new functions to assist the driver’s decision. Given this scenario, the dissertation presents the results of research to characterize driving styles of drivers using available information in vehicular communication network. This master thesis focuses on the process of information extraction from a vehicular network, analysis of the extracted features, and driver classification based on the extracted data. The study aims to identify aggressive driving behavior using real-world data collected from five different trucks running for a period of three months. The driver scoring method used in this study dynamically identifies aggressive driving behavior during predefined time windows by calculating jerk derived from the acquired data. In addition, the K-Means clustering technique was explored to group different behaviors into data clusters. Chapter 2 provides a comprehensive overview of the theoretical framework necessary for the successful development of this thesis. Chapter 3 details the process of data extraction from real and uncontrolled environments, including the steps taken to extract and refine the data. Chapter 4 focuses on the study of features extracted from the preprocessed data, and Chapter 5 presents two methods for identifying or grouping the data into clusters. The results obtained from this study have advanced the state-of-the-art of driver behavior classification and have proven to be satisfactory. The thesis addresses the gap in the literature by using data from real and uncontrolled environments, which required preprocessing before analysis. Furthermore, the study represents one of the pioneering studies conducted on commercial vehicles in an uncontrolled environment. In conclusion, this thesis provides insights into the development of driver behavior classification models using real-world data. Future research can build upon the techniques presented in this study and further refine the classification models. The thesis also addresses the threats to validity that were mitigated and provides recommendations for future research

Brazilian rhythms on the drum set: stylizations of baiao, frevo and maracatu by drummers Airto Moreira, Nene and Marcio Bahia.

The objective of this research is to gather and analyze stylizations of Brazilian folk rhythms baião, frevo and maracatu in contemporary Brazilian jazz. For this end, I examined transcriptions from well-known contemporary drummers Airto Moreira, Nenê and Márcio Bahia. Firstly, I reviewed the path of the drum set in Brazil by examining the important contributions made by drummers Luciano Perrone and Edison Machado. After that, I presented musical characteristics of baião, maracatu and frevo in their original environment, followed by analysis of each rhythm’s stylizations to the drum set made by drummers Airto Moreira, Nenê and Márcio Bahia. I concluded that, to successfully transpose these Northeast Brazilian rhythms from percussion ensembles to the drum set, it is important to identify key patterns from the original source to be featured on the stylization, as well as to consider technical solutions that are already part of the drum set vocabulary