69 research outputs found

    MACOC: a medoid-based ACO clustering algorithm

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    The application of ACO-based algorithms in data mining is growing over the last few years and several supervised and unsupervised learning algorithms have been developed using this bio-inspired approach. Most recent works concerning unsupervised learning have been focused on clustering, showing great potential of ACO-based techniques. This work presents an ACO-based clustering algorithm inspired by the ACO Clustering (ACOC) algorithm. The proposed approach restructures ACOC from a centroid-based technique to a medoid-based technique, where the properties of the search space are not necessarily known. Instead, it only relies on the information about the distances amongst data. The new algorithm, called MACOC, has been compared against well-known algorithms (K-means and Partition Around Medoids) and with ACOC. The experiments measure the accuracy of the algorithm for both synthetic datasets and real-world datasets extracted from the UCI Machine Learning Repository

    Orthogonal methods based ant colony search for solving continuous optimization problems

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    Research into ant colony algorithms for solving continuous optimization problems forms one of the most significant and promising areas in swarm computation. Although traditional ant algorithms are designed for combinatorial optimization, they have shown great potential in solving a wide range of optimization problems, including continuous optimization. Aimed at solving continuous problems effectively, this paper develops a novel ant algorithm termed "continuous orthogonal ant colony" (COAC), whose pheromone deposit mechanisms would enable ants to search for solutions collaboratively and effectively. By using the orthogonal design method, ants in the feasible domain can explore their chosen regions rapidly and e±ciently. By implementing an "adaptive regional radius" method, the proposed algorithm can reduce the probability of being trapped in local optima and therefore enhance the global search capability and accuracy. An elitist strategy is also employed to reserve the most valuable points. The performance of the COAC is compared with two other ant algorithms for continuous optimization of API and CACO by testing seventeen functions in the continuous domain. The results demonstrate that the proposed COAC algorithm outperforms the others

    Biologia floral e polinização em girassol (Helianthus annuus L.) por abelhas africanizadas

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    O girassol (Helianthus annuus  L.) é uma planta de polinização cruzada  e os seus principais polinizadores são as abelhas. Com a polinização por insetos o girassol produz sementes, sendo a abelha africanizada  Apis mellifera  L. o agente mais efetivo. A  performance desta abelha como polinizadora depende de vários fatores, sendo eles, a disponibilidade de pólen e néctar na flor, condições climáticas e aspectos físicos do solo. O girassol é pouco sensível às variações no fotoperíodo, fato este que permite seu escalonamento de produção em quase todo o território nacional. No Brasil uma grande parte do território é considerada apta para o cultivo por apresentar condições climáticas satisfatórias, sendo que atualmente esta oleaginosa é cultivada em todos os continentes. O objetivo desta revisão é reunir dados para uma compilação de informações referentes à cultura do girassol e a importância de A. mellifera L., principalmente as africanizadas na polinização de H. annuus L.&nbsp

    Sexual life and dysfunction after maternal morbidity: A systematic review

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    © 2015 Andreucci et al. Background: Because there is a lack of knowledge on the long-term consequences of maternal morbidity/near miss episodes on women's sexual life and function we conducted a systematic review with the purpose of identifying the available evidence on any sexual impairment associated with complications from pregnancy and childbirth. Methods: Systematic review on aspects of women sexual life after any maternal morbidity and/or maternal near miss, during different time periods after delivery. The search was carried out until May 22nd, 2015 including studies published from 1995 to 2015. No language or study design restrictions were applied. Maternal morbidity as exposure was split into general or severe/near miss. Female sexual outcomes evaluated were dyspareunia, Female Sexual Function Index (FSFI) scores and time to resume sexual activity after childbirth. Qualitative syntheses for outcomes were provided whenever possible. Results: A total of 2,573 studies were initially identified, and 14 were included for analysis after standard selection procedures for systematic review. General morbidity was mainly related to major perineal injury (3rd or 4th degree laceration, 12 studies). A clear pattern for severity evaluation of maternal morbidity could not be distinguished, unless when a maternal near miss concept was used. Women experiencing maternal morbidity had more frequently dyspareunia and resumed sexual activity later, when compared to women without morbidity. There were no differences in FSFI scores between groups. Meta-analysis could not be performed, since included studies were too heterogeneous regarding study design, evaluation of exposure and/or outcome and time span. Conclusion: Investigation of long-term repercussions on women's sexual life aspects after maternal morbidity has been scarcely performed, however indicating worse outcomes for those experiencing morbidity. Further standardized evaluation of these conditions among maternal morbidity survivors may provide relevant information for clinical follow-up and reproductive planning for women

    Validation of the WHO Disability Assessment Schedule (WHODAS 2.0) 12-item tool against the 36-item version for measuring functioning and disability associated with pregnancy and history of severe maternal morbidity

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    © 2018 World Health Organization; licensed by John Wiley & Sons Ltd on behalf of International Federation of Gynecology and Obstetrics. Objective: To validate the WHO Disability Assessment Schedule 2.0 (WHODAS 2.0) 12-item tool against the 36-item version for measuring functioning and disability associated with pregnancy and the occurrence of maternal morbidity. Methods: This is a secondary analysis of the Brazilian retrospective cohort study on long-term repercussions of severe maternal morbidity (SMM) among women who delivered at a tertiary facility (COMMAG study). We compared WHODAS-12 and WHODAS-36 scores of women with and without SMM using measures of central tendency and variability, tests for instruments’ agreement (Bland-Altman plot), confirmatory factor analysis (CFA), and Cronbach alpha coefficient for internal consistency. Results: The COMMAG study enrolled 638 women up to 5 years postpartum. Although the median WHODAS-36 and -12 scores for all women were statistically different (13.04 and 11.76, respectively; P<0.001), there was a strong linear correlation between them. Furthermore, the mean difference and the differences in variance analyses demonstrated agreement of total scores between the two versions. CFA demonstrated how the WHODAS-12 questions are divided into six previously defined factors and Cronbach alpha showed good internal consistency. Conclusion: WHODAS-12 demonstrated agreement with WHODAS-36 for total score and was a good instrument for screening functioning and disability among postpartum women, with and without SMM

    The impact of hypertension, hemorrhage, and other maternal morbidities on functioning in the postpartum period as assessed by the WHODAS 2.0 36-item tool

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    © 2018 World Health Organization; licensed by John Wiley & Sons Ltd on behalf of International Federation of Gynecology and Obstetrics. Objective: To assess the scores of postpartum women using the WHO Disability Assessment Schedule 2.0 36-item tool (WHODAS-36), considering different morbidities. Methods: Secondary analysis of a retrospective cohort of women who delivered at a referral maternity in Brazil and were classified with and without severe maternal morbidity (SMM). WHODAS-36 was used to assess functioning in postpartum women. Percentile distribution of total WHODAS score was compared across three groups: Percentile (P)90. Cases of SMM were categorized and WHODAS-36 score was assessed according to hypertension, hemorrhage, or other conditions. Results: A total of 638 women were enrolled: 64 had mean scores below P90 (41.3). Of women scoring above P>90, those with morbidity had a higher mean score than those without (44.6% vs 36.8%, P=0.879). Women with higher WHODAS-36 scores presented more complications during pregnancy, especially hypertension (47.0% vs 37.5%, P=0.09). Mean scores among women with any complication were higher than those with no morbidity (19.0 vs 14.2, P=0.01). WHODAS-36 scores were higher among women with hypertensive complications (19.9 vs 16.0, P=0.004), but lower among those with hemorrhagic complications (13.8 vs 17.7, P=0.09). Conclusions: Complications during pregnancy, childbirth, and the puerperium increase long-term WHODAS-36 scores, demonstrating a persistent impact on functioning among women, up to 5 years postpartum

    Applying the Maternal Near Miss Approach for the Evaluation of Quality of Obstetric Care: A Worked Example from a Multicenter Surveillance Study

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    Objective. To assess quality of care of women with severe maternal morbidity and to identify associated factors. Method. This is a national multicenter cross-sectional study performing surveillance for severe maternal morbidity, using the World Health Organization criteria. the expected number of maternal deaths was calculated with the maternal severity index (MSI) based on the severity of complication, and the standardized mortality ratio (SMR) for each center was estimated. Analyses on the adequacy of care were performed. Results. 17 hospitals were classified as providing adequate and 10 as nonadequate care. Besides almost twofold increase in maternal mortality ratio, the main factors associated with nonadequate performance were geographic difficulty in accessing health services (P < 0.001), delays related to quality of medical care (P = 0.012), absence of blood derivatives (P = 0.013), difficulties of communication between health services (P = 0.004), and any delay during the whole process (P = 0.039). Conclusions. This is an example of how evaluation of the performance of health services is possible, using a benchmarking tool specific to Obstetrics. in this study the MSI was a useful tool for identifying differences in maternal mortality ratios and factors associated with nonadequate performance of care.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Campinas UNICAMP, Sch Med Sci, Dept Obstet & Gynaecol, BR-13083881 Campinas, SP, BrazilCtr Res Reprod Hlth Campinas Cemicamp, BR-13083888 Campinas, SP, BrazilUniv Fed Amazonas, Manaus, Amazonas, BrazilSch Med Sci, CISAM, Recife, PE, BrazilUniv Fed Ceara, Fortaleza, Ceara, BrazilUniv Fed Bahia, Salvador, BA, BrazilHosp Geral Cesar Cals, Fortaleza, Ceara, BrazilHosp Geral Fortaleza, Fortaleza, Ceara, BrazilMaternidade Odete Valadares, Belo Horizonte, MG, BrazilHosp Materno Infantil, Goiania, Go, BrazilInst Materno Infantil Pernambuco, Recife, PE, BrazilUniv Fed Pernambuco, Recife, PE, BrazilUniv Fed Campina Grande, Campina Grande, PB, BrazilUniv Fed Maranhao, Sao Luis, MA, BrazilUniv Fed Parana, BR-80060000 Curitiba, Parana, BrazilUniv Fed Paraiba, BR-58059900 Joao Pessoa, Paraiba, BrazilHosp Maternidade Fernando Magalhaes, Rio de Janeiro, RJ, BrazilUniv Fed Rio Grande do Sul, Porto Alegre, RS, BrazilHosp Maternidade Celso Pierro, Campinas, SP, BrazilInst Fernandes Figueira Fiocruz, Rio de Janeiro, RJ, BrazilHosp Israelita Albert Einstein, São Paulo, BrazilUniv State São Paulo, Botucatu, SP, BrazilJundiai Sch Med, Jundiai, SP, BrazilUniv São Paulo, BR-14049 Ribeirao Preto, SP, BrazilSanta Casa Limeira, Limeira, SP, BrazilSanta Casa Sao Carlos, Sao Carlos, SP, BrazilMaternidade Leonor Mendes de Barros, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilCNPq: 402702/2008-5Web of Scienc

    Skin color and severe maternal outcomes: evidence from the brazilian network for surveillance of severe maternal morbidity

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    Taking into account the probable role that race/skin color may have for determining outcomes in maternal health, the objective of this study was to assess whether maternal race/skin color is a predictor of severe maternal morbidity. This is a secondary analysis of the Brazilian Network for Surveillance of Severe Maternal Morbidity, a national multicenter cross-sectional study of 27 Brazilian referral maternity hospitals. A prospective surveillance was performed to identify cases of maternal death (MD), maternal near miss (MNM) events, and potentially life-threatening conditions (PLTC), according to standard WHO definition and criteria. Among 9,555 women with severe maternal morbidity, data on race/skin color was available for 7,139 women, who were further divided into two groups: 4,108 nonwhite women (2,253 black and 1,855 from other races/skin color) and 3,031 white women. Indicators of severe maternal morbidity according to WHO definition are shown by skin color group. Adjusted Prevalence Ratios (PRadj - 95%CI) for Severe Maternal Outcome (SMO=MNM+MD) were estimated according to sociodemographic/obstetric characteristics, pregnancy outcomes, and perinatal results considering race. Results. Among 7,139 women with severe maternal morbidity evaluated, 90.5% were classified as PLTC, 8.5% as MNM, and 1.6% as MD. There was a significantly higher prevalence of MNM and MD among white women. MNMR (maternal near miss ratio) was 9.37 per thousand live births (LB). SMOR (severe maternal outcome ratio) was 11.08 per 1000 LB, and MMR (maternal mortality ratio) was 170.4 per 100,000 LB. Maternal mortality to maternal near miss ratio was 1 to 5.2, irrespective of maternal skin color. Hypertension, the main cause of maternal complications, affected mostly nonwhite women. Hemorrhage, the second more common cause of maternal complication, predominated among white women. Nonwhite skin color was associated with a reduced risk of SMO in multivariate analysis. Nonwhite skin color was associated with a lower risk for severe maternal outcomes. This result could be due to confounding factors linked to a high rate of Brazilian miscegenation.2019CNPQ - Conselho Nacional de Desenvolvimento Científico e Tecnológico402702/2008-
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