Universidade de Pernambuco

About: Universidade de Pernambuco is a education organization based out in Recife, Brazil. It is known for research contribution in the topics: Population & Medicine. The organization has 6147 authors who have published 6948 publications receiving 73648 citations.

The effect of recency to human mobility

Abstract: In recent years, we have seen scientists attempt to model and explain human dynamics and in particular human movement. Many aspects of our complex life are affected by human movement such as disease spread and epidemics modeling, city planning, wireless network development, and disaster relief, to name a few. Given the myriad of applications, it is clear that a complete understanding of how people move in space can lead to considerable benefits to our society. In most of the recent works, scientists have focused on the idea that people movements are biased towards frequently-visited locations. According to them, human movement is based on a exploration/exploitation dichotomy in which individuals choose new locations (exploration) or return to frequently-visited locations (exploitation). In this work we focus on the concept of recency. We propose a model in which exploitation in human movement also considers recently-visited locations and not solely frequently-visited locations. We test our hypothesis against different empirical data of human mobility and show that our proposed model replicates the characteristic patterns of the recency bias.

Microbiological process in agroforestry systems. A review

Abstract: Soils around the world are degraded due to inappropriate management practices. There is thus the necessity to find more conservationist agricultural systems. Agroforestry system is an alternative system that helps prevent land degradation while allowing continuing use of land to produce crops and livestock on a sustainable basis. Agroforestry system is a form of sustainable land use that combines trees and shrubs with crops and livestock in ways that increase and diversify farm and forest production while also conserving natural resources. This system enhances organic carbon accumulation in soils by the inclusion of cover crops and permanent vegetation, which is expected to increase the soil microbial biomass. The use of microorganisms aims at improving nutrient availability for plants. Currently, there is an emerging demand to decrease the dependence on chemical fertilizers and achieve sustainable agriculture and agroforestry. Arbuscular mycorrhizal fungi, plant growth-promoting rhizobacteria, and the association of rhizobia with leguminous plants are mutualistic symbioses of high economic importance for increasing agricultural production. The biological nitrogen fixation (BNF) process is an economically attractive and ecologically sound method to reduce external nitrogen input and improve the quality and quantity of internal resources. BNF by associative diazotrophic bacteria is a spontaneous process where soil nitrogen is limited and adequate carbon sources are available. However, the ability of these bacteria to contribute to increased crop yields is only partly a result of BNF. The successful use of legumes is dependent upon appropriate attention to the formation of effective symbioses with root nodule bacteria. An essential component for increasing the use of legumes is the integration of plant breeding and cultivar development, with appropriate research leading to the selection of elite strains of root nodule bacteria. An expansion of the utility of inoculants is also necessary to develop a broad conceptual framework and methodology that is supported by scientific arguments; it is destined to impact assessment of the use of new biological products in agriculture.

Lightweight Static Analysis for GUI Testing

Abstract: GUI testing is an active research area. The open challenge is the judicious generation of event sequences (an event sequence encodes a user interaction). A major advance in this direction is the use of a black-box model to systematically generate event sequences that are executable on the GUI. The black-box model can be, e.g., an Event Flow Graph (EFG) or an Event Sequence Graph (ESG). In this paper we propose a new approach to select relevant event sequences among the event sequences generated by a black-box model. We express the relevance of an event sequence by a precisely defined dependency between a fixed number of events in the event sequence. Departing from a pure black-box approach we apply a static analysis to the byte code of the application. This allows us to infer a dependency graph, which we call Event Dependency Graph (EDG). We use the EDG together with a black-box model to construct a set of relevant event sequences among the executable ones. We have implemented our approach in a new tool. We evaluate the approach on four open source GUI applications. With the specific choice of a lightweight static analysis, the approach scales to large applications and, at the same time, leads to an informed selection of event sequences. Using our approach we are able to find previously undetected bugs.

Biofilm production by clinical isolates of Pseudomonas aeruginosa and structural changes in LasR protein of isolates non biofilm-producing.

Abstract: Introduction Biofilm production is an important mechanism for the survival of Pseudomonas aeruginosa and its relationship with antimicrobial resistance represents a challenge for patient therapeutics. P. aeruginosa is an opportunistic pathogen frequently associated to nosocomial infections, especially in imunocompromised hosts. Objectives Analyze the phenotypic biofilm production in P. aeruginosa isolates, describe clonal profiles, and analyze quorum sensing (QS) genes and the occurrence of mutations in the LasR protein of non-biofilm producing isolates. Methods Isolates were tested for biofilm production by measuring cells adherence to the microtiter plates. Clonal profile analysis was carried out through ERIC-PCR, QS genes were by specific PCR. Results The results showed that 77.5% of the isolates were considered biofilm producers. The results of genotyping showed 38 distinct genetic profiles. As for the occurrence of the genes, 100% of the isolates presented the lasR , rhlI and rhlR genes, and 97.5%, presented the lasI gene. In this study nine isolates were not biofilm producers. However, all presented the QS genes. Amplicons related to genes were sequenced in three of the nine non-biofilm-producing isolates (all presenting different genetic similarity profile) and aligned to the sequences of those genes in P. aeruginosa strain PAO1 (standard biofilm-producing strain). Alignment analysis showed an insertion of three nucleotides (T, C and G) causing the addition of an amino acid valine in the sequence of the LasR protein, in position 53. Conclusion The modeling of the resulting LasR protein showed a conformational change in its structure, suggesting that this might be the reason why these isolates are unable to produce biofilm.

Moving More and Sitting Less as Healthy Lifestyle Behaviors are Protective Factors for Insomnia, Depression, and Anxiety Among Adolescents During the COVID-19 Pandemic

Abstract: Purpose This study aimed to investigate associations of physical activity time (PAT) and sitting time (ST) independently and jointly with insomnia, depressive and anxiety symptoms among Chinese adolescents in the context of COVID-19. Methods A cross-sectional study including 965 adolescents (mean age = 15.26, SD = 0.46) was conducted in May 2020. PAT, ST and the symptoms of insomnia, depression and anxiety were assessed with the International Physical Activity Questionnaire Short Form, the Youth Self-Rating Insomnia Scales, the 9-item Patient Health Questionnaire and the Generalized Anxiety Disorder scale via an online survey platform. Logistic regression was used to analyze the association between COVID-19-related fear, PAT, ST and combinations of PAT and ST with insomnia, depressive and anxiety symptoms. Results COVID-19-related fear was associated with higher odds of insomnia, depressive and anxiety symptoms. PAT was associated with lower odds of insomnia and depressive symptoms, while ST was associated with higher odds of these three symptoms. After combining PAT and ST, the group with both low PAT and high ST was set as the referent. For insomnia, groups with low ST reported significantly lower odds of symptoms. For depression, groups with high PAT and/or low ST reported lower odds of symptoms. Regarding anxiety, only the group with both high PAT and low ST reported lower odds of symptoms. Generally, group with both high PAT and low ST reported lower odds of the three symptoms than the referent. Conclusion COVID-19-related fear was a risk factor for developing insomnia, depressive and anxiety symptoms among Chinese adolescents. Fortunately, moving more and sitting less were good for sleep and mental health in Chinese adolescents during the pandemic. Educators should help adolescents to be more physically active in their daily life in the primary prevention of adolescent insomnia, depression and anxiety.