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 & Artificial neural network. The organization has 6147 authors who have published 6948 publications receiving 73648 citations.

Hydrolytic and Biological Degradation of Bulk-fill and Self-adhering Resin Composites.

Abstract: Clinical Relevance The interaction between different substances on resin composite surfaces is a critical issue in the assessment of the clinical longevity of restorative materials.

Exact results of the limited penetrable horizontal visibility graph associated to random time series and its application.

Abstract: The limited penetrable horizontal visibility algorithm is an analysis tool that maps time series into complex networks and is a further development of the horizontal visibility algorithm. This paper presents exact results on the topological properties of the limited penetrable horizontal visibility graph associated with independent and identically distributed (i:i:d:) random series. We show that the i.i.d: random series maps on a limited penetrable horizontal visibility graph with exponential degree distribution, independent of the probability distribution from which the series was generated. We deduce the exact expressions of mean degree and clustering coefficient, demonstrate the long distance visibility property of the graph and perform numerical simulations to test the accuracy of our theoretical results. We then use the algorithm in several deterministic chaotic series, such as the logistic map, H´enon map, Lorenz system, energy price chaotic system and the real crude oil price. Our results show that the limited penetrable horizontal visibility algorithm is efficient to discriminate chaos from uncorrelated randomness and is able to measure the global evolution characteristics of the real time series.

Symbolic data analysis tools for recommendation systems

Abstract: Recommender systems have become an important tool to cope with the information overload problem by acquiring data about user behavior. After tracing the user’s behavior, through actions or rates, computational recommender systems use information- filtering techniques to recommend items. In order to recommend new items, one of the three major approaches is generally adopted: content-based filtering, collaborative filtering, or hybrid filtering. This paper presents three information-filtering methods, each of them based on one of these approaches. In our methods, the user profile is built up through symbolic data structures and the user and item correlations are computed through dissimilarity functions adapted from the symbolic data analysis (SDA) domain. The use of SDA tools has improved the performance of recommender systems, particularly concerning the find good items task measured by the half-life utility metric, when there is not much information about the user.

Changes in family structure and regret following tubal sterilization

Abstract: Tubal sterilization is one of the contraceptive methods whose use has increased the most in Brazil, but a growing number of women have expressed regret after the procedure. A case-control study was conducted at the Centro Integrado de Saude Amaury de Medeiros (CISAM), Recife, Pernambuco, Brazil, in 1997 to investigate the association between changes in family structure and request for or submittal to surgical reversal of tubal sterilization, comparing 304 sterilized women who had requested or submitted to reversal of tubal sterilization and 304 women who were also sterilized but had not requested, had not submitted to, and who did not wish to submit to reversal. The simple and adjusted odds ratios were estimated using logistic regression. The results of the current study showed that death of children, partners without children prior to the current union, and partner change after tubal sterilization were associated with the request for or submittal to reversal of tubal sterilization. More strict criteria are suggested in the indication of tubal sterilization, including an in-depth profile of the woman requesting tubal sterilization and identification of risk factors for future regret.

Effectiveness of a Behavior Change Program on Physical Activity and Eating Habits in Patients With Hypertension: A Randomized Controlled Trial

Abstract: Background: This study aimed to analyze the effect of a behavior change program, called Vida Ativa Melhorando a Saude (VAMOS), on physical activity, eating habits, and quality of life in patients with hypertension. Methods: A randomized controlled trial was carried out in 90 patients with hypertension (57.8 ± 9.9 y). They were randomly assigned to 2 groups: VAMOS group (n = 45) and control group (n = 45). The VAMOS group participated in a behavioral change program aimed at motivating changes in physical activity and nutrition behavior for 12 weeks. Physical activity, eating habits, quality of life, self-efficacy, and social support were evaluated at preintervention and postintervention. Results: The control group increased sedentary time (407 ± 87 vs 303 ± 100 min/d; P < .05) and sedentary bouts (434 ± 86 vs 336 ± 98 min/d; P < .05) and reduced total physical activity (553 ± 87 vs 526 ± 86 min/d; P < .05). The VAMOS group improved the general healthy eating habits score (36.9 ± 6.6 vs 43.4 ± 5.8; P < .05)...