Detecção de dano em estruturas baseada em técnicas de aprendizado híbrido

Engineering structures are often subject to changes in their dynamic properties due to various factors such as deterioration of construction due to time of use, the lack of maintenance, adverse environmental and operational effects, unexpected loads, structural reinforcement procedures, among others. In most cases, these modifications may be associated with structural damage. Continuous monitoring of the dynamic behavior of a structure makes it possible to investigate and analyze changes to ensure their integrity, ensuring greater comfort and safety for users and enabling more effective repair and maintenance actions, directly impacting the reduction of operating costs. For such, monitoring systems must have computational tools able to evaluate the acquired information in real time and continuously. In this dissertation, a new approach based on the direct analysis of acceleration measurements to detect structural damage and modifications using computational intelligence techniques is presented. The approach is to use together supervised (RNA) and unsupervised (k-means) classification methods to construct a hybrid classifier. The goal is to detect not only known damage states but also unidentified structural states. The idea is thus to allow the real-time monitoring of structural integrity, providing answers automatically and continuously, based only on vibrational testing environments with the structure in operation. To attest to the robustness of this approach, data from numerical simulations and experimental tests performed in the laboratory and in situ are used. The results show promising performance of the proposed methodologyAs estruturas de engenharia estão frequentemente sujeitas a alterações em suas propriedades dinâmicas por conta de diversos fatores, tais como a deterioração da construção devido ao tempo de uso, a falta de manutenção, os efeitos ambientais e operacionais adversos, os carregamentos inesperados, os procedimentos de reforço estrutural, entre outros. Na maioria dos casos, essas modificações podem estar associadas a danos estruturais. O monitoramento contínuo do comportamento dinâmico de uma estrutura possibilita a investigação e a análise de alterações com o objetivo de assegurar sua integridade, garantindo maior conforto e segurança aos usuários, além de possibilitar ações mais eficazes de reparo e manutenção, impactando diretamente na redução dos custos operacionais. Para tanto, sistemas de monitoramento devem dispor de ferramentas computacionais aptas a avaliar as informações adquiridas em tempo real e continuamente. Nesta dissertação, uma nova abordagem baseada na análise direta de medições de aceleração para detectar danos e modificações estruturais utilizando técnicas de inteligência computacional é apresentada. A abordagem consiste na utilização em conjunto de métodos de classificação supervisionados (RNA) e não supervisionados (k-means) para a construção de um classificador híbrido. O objetivo é detectar não apenas estados de dano já conhecidos, mas também estados estruturais que ainda não foram identificados. A ideia é permitir, dessa forma, o monitoramento da integridade estrutural em tempo real, provendo respostas de forma automática e contínua, baseando-se apenas em testes vibracionais ambientes com a estrutura em operação. Para atestar a robustez dessa abordagem, dados oriundos de simulações numéricas e de ensaios experimentais realizados em laboratório e in situ são utilizados. Os resultados obtidos demonstram desempenho promissor da metodologia proposta.FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerai

Morphometric Changes in Three Species of Euglossini (Hymenoptera: Apidae) in Response to Landscape Structure

Fragmentation and expansion of agricultural activities are sufficient factors for strongly impacting the biodiversity. Thus, sustainable practices of land use, such as agroforestry systems, are adopted with proposal of improving environmental quality and restore ecological processes. In flying insects, fragmentation may cause changes in the wing shape and size. Therefore, we evaluated the wing size and shape of three species of Euglossini (Eulaema atleticana Nemésio, Euglossa cordata (Linnaeus) and Euglossa ignita Smith) at response to landscape structure. The analysed specimens were collected in five areas, four forest areas with strong anthropic influence and an agroforestry system area. The results of the wing shape analysis have showed that the individuals of the three collected species within the agroforestry system diverge significantly (p<0.05) from those collected in the other areas. On the wings of Eg. cordata and Eg. ignita, differences in shape have occurred mainly in the medial region, which actively participates in the individual's flying ability. The wing size has showed meaningful difference only to the population of Eg. ignita (p=0,005). For Eg. cordata and El. atleticana, there was a significant correlation (r<0.05) between the morphometric data and the landscape metrics, which shows a close relationship between these species and the forest cover. The wing shape and size pursue an important function for the individual's ability in the environment, such as dispersion capacity and fertility rate, respectively. We concluded that the morphometric differences can reveal the existence of environmental stress for the biodiversity, therefore, contribute for environmental quality monitoring studies

Population Structure of Melipona subnitida Ducke (Hymenoptera: Apidae: Meliponini) at the Southern Limit of its Distribution Based on Geometric Morphometrics of Forewings

Bees provide fundamental services to humanity, and the world has been concerned about the rapid loss of genetic diversity that these organisms have been suffering. The stingless bee Melipona subnitida is endemic to northeastern Brazil and has high potential for the production of honey and wax; it is also an important pollinator in the Caatinga biome. Populations of M. subnitida have increasingly declined due to predatory extractivism and destruction of its habitat. However, knowledge about its population structure could give insights on strategies for monitoring and conservation of this species. Here we collected workers from nine sites located at the southern limit of the species distribution and employed geometric morphometric techniques on their forewings in search of covariance between sampling site and wing morphology. It was observed a very significant correlation between both variables, indicating that the divergence among the sampled populations of M. subnitida was due to geographical distance among the sampling sites and, hence, suggesting the formation of different groups of populations along the studied geographical zone, each one with specific characteristics. Since M. subnitida habitat has been increasingly fragmented thus difficulting the genetic flow among populations, our findings will contribute to the formulation of management and conservation plans for this species in order to preserve its genetic diversity and, hence, to contribute to the generation of income for beekeepers in meliponiculture programs

Fluctuating Asymmetry in Melipona scutellaris (L.) 1811 (Hymenoptera: Apidae) Associated to Stress due to Transportation of Colonies

Transportation to long distances and handling of colonies can affect development and survival conditions of bees. Our study investigated the stress intensity of individuals of Melipona scutellaris Latreille, 1811, due to transportation of colonies to long distances, within the natural range of the species. We used 746 bee workers. The right and left forewings were removed and measured using 15 landmarks in vein insertions. Individuals were divided into four groups: (1) workers collected at the origin site, (2) workers emerged at the place of destination in pupal stage during transportation, (3) workers emerged at the destination site in the 3rd instar of larval stage during transportation, and (4) workers collected after three months of colony establishment at the destination site. The Procrustes ANOVA showed significant results as well as the presence of Fluctuating Asymmetry (FA) in all treatments for the shape of wings (P<0.01). However, in the comparison of groups using the One-Way ANOVA, only workers that emerged at the destination site in the 3rd instar of larval stage during transportation (Group 3) significantly differentiated (P<0.05) from the others, with a higher FA index. The larval stage underwent more stress due to colony transportation. Beekeepers should take good care of colonies during transportation in order to minimize damages to workers to prevent quality loss of services and products offered by bees

Population Divergence of Melipona scutellaris (Hymenoptera: Meliponina) in Two Restricted Areas in Bahia, Brazil

Melipona scutellaris Latreille has great economic and ecological importance, especially because it is a pollinator of native plant species. Despite the importance of this species, there is little information about the conservation status of their populations. The objective of this study was to assess the diversity in populations of M. scutellaris coming from a Semideciduous Forest Fragment and an Atlantic Forest Fragment in the Northeast Brazil, through geometric morphometric analysis of wings in worker bees. In each area, worker bees were collected from 10 colonies, 10 workers per colony. To assess the diversity on the right wings of worker bees, 15 landmarks were plotted and the measures were used in analysis of variance and multivariate analysis, principal component analysis, discriminant analysis and clustering analysis. There were significant differences in the shape of the wing venation patterns between colonies of two sites (Wilk’s λ = 0.000006; p < 0.000001), which is probably due to the geographical distance between places of origin which impedes the gene flow between them. It indicates that inter and intrapopulation morphometric variability exists (p <0.000001) in M. scutellaris coming from two different biomes, revealing the existence of diversity in these populations, which is necessary for the conservation of this bee species.

Morphometric Variability among Populations of Euglossa cordata (Hymenoptera: Apidae: Euglossini) from Different Phytophysiognomies

Geometric morphometrics is a tool capable of measuring the response of organisms to different environmental pressures. We tested the hypothesis that E. cordata wing morphometry, as an indicator of response to environmental pressure, it would vary depending on habitat changes, in the Atlantic Forest, Savanna and dry forest (Caatinga). For analysis of wing shape and size, 18 landmarks were digitized at the intersections of the wing veins 348 individuals. Except for the two populations sampled in Chapada Diamantina, the wing shape had significant statistical variations among the populations (p < 0.05). The wing size variation was also statistically significant among populations (p < 0.05).  Although E. cordata is a species tolerant to different environments, the observed morphometric variability may be related to population adaptations to the conditions of each phytophysiognomy

Factors Associated with Malocclusion in Preschool Children in a Brazilian Small Town

Objective: To analyze the prevalence and factors associated with malocclusions in preschool children. Material and Methods: A census, epidemiological study, with a cross-sectional, descriptive and analytic sample, was carried out with children aged between 4 and 6 years, matriculated in preschools in the town of Aiquara, Bahia, Brazil. Malocclusion in the deciduous dentition was determined through the application of the index proposed by WHO, with the Foster and Hamilton criteria also being incorporated. The data was tabulated in duplicate in a Microsoft Excel spreadsheet and following correction, was analyzed using the SPSS, STATA and PAST Software. In order to identify the associated factors, we opted for Multiple Poisson regression analysis and Principal Component Analysis (PCA). Results: A total of 148 children were examined and the general prevalence of malocclusions was 69.59%, with 57.5% in the group of 4-year-old, 76.92% those aged 5 years old and 72.46% among children aged 6 years old. In terms of primary canines, 66.2% were identified as class I, 25.7% as class II and 8.1% as class III. Normal overjet was 41.2%, increased overjet 34.5%, edge to edge bite 17.6% and anterior crossbite 6.8%. The normal overbite 51.4%, reduced 20.9% and deep 8.1%. Of the individuals, 20.9% had posterior crossbite. In the Poisson regression analysis and PCA, a statistical association between the malocclusions and dental caries, duration of use of pacifiers, onychophagia and thumb sucking, was identified. Conclusion: The prevalence of malocclusion in preschool children in the small town of Aiquara is high and the associated factors identified are capable of control and prevention

Risk of local extinction and genetic diversity of Melipona quadrifasciata (Apidae: Meliponini) in a possible Northeastern limit of its distribution in Brazil

Rapid loss of genetic diversity among eusocial bees, and extinction of their local population has become a major world concern. Populations of M. quadrifasciata have increasingly declined due to predatory extractivism and destruction of their habitat. Knowledge of their local population could give insights on the strategies for monitoring and conservation of this species. In this study, initially, 14 colonies (140 workers) from the Northern limit of the Northeastern sandbank of the Atlantic Forest were analyzed employing geometric morphometrics techniques. Then the cytochrome b gene sequences and ISSR primers were utilized for molecular analysis. The results were compared with the results of 30 M. quadrifasciata colonies (300 workers) found in the semiarid Caatinga region. The morphometrics and the molecular analysis suggested the formation of disjunct populations between the studied geographical zones. All the 14 colonies analyzed from the river São Francisco region were found on the Southern margin of the river São Francisco and they all belonged to one single haplotype. No colonies were found on the Northern bank of the river. We suggest that the river São Francisco is an effective georgraphical barrier for the distribution of this species and propose an urgent need for the development of a conservation program for the population of M. quadrifasciata as it represents a unique haplotype in the region. Also their nesting habit exclusively in the diseased coconut trees which probably will be replaced by new trees, create the risk of population extinction due to the lack of nesting site

Pollen spectrum of honey of Apis mellifera L. and stingless bees (Hymenoptera: Apidae) from the semi-arid region of Bahia State, Brazil

Pollen in honey reflects its botanical origin and melissopalynology is used to identify origin, type, and quantities of pollen grains of the botanical species visited by bees. This study aimed to identify the pollen spectrum of honeys from Apis mellifera and stingless bees produced in the semi-arid region of Bahia, Brazil. We analysed 78 honey samples, which were submitted to the acetolysis process for identification and quantification of pollen types. Fabaceae, Asteraceae and Euphorbiaceae were the most predominant families in pollen types. For Fabaceae, the most representative pollen types were Chamaecrista 1, Mimosa caesalpiniifolia, Mimosa pudica, Mimosa tenuiflora, Prosopis and Senna. The results indicate that the flora explored by the bees to collect nectar is diverse in the semi-arid region of Bahia and the honeys analysed were classified as multifloral.info:eu-repo/semantics/publishedVersio

MEGAESÔFAGO SECUNDÁRIO A ESTENOSE ESOFÁGICA EM GATO: RELATO DE CASO

Megaesôfago é caracterizado por uma dilatação esofágica com comprometimento do seu peristaltismo. O presente estudo relata um caso clínico de megaesôfago secundário a estenose esofágica uma gata, siamesa, com 1 ano de idade, com histórico de regurgitação crônica refratária ao tratamento. O animal apresentava histórico de vômito recorrente após ser submetida à castração e receber medicação pós-operatória na forma de comprimidos. O paciente apresentava emagrecimento progressivo, regurgitação crônica e grave desidratação. O exame radiográfico mostrou acúmulo de conteúdo no esôfago torácico sugerindo obstrução que foi confirmado no exame contrastado. A paciente foi estabilizado e submetido à esofagectomia para restabelecimento do fluxo da ingesta no esôfago. No pós-operatório recebeu tratamento suporte com fluido intravenoso, antibiótico e anti-inflamatório e foi instituído manejo alimentar com dieta líquida ministrada com o animal em posição bipedal. A recuperação do paciente foi satisfatória. Concluindo-se que a estenose esofágica é uma alteração grave que pode levar ao megaesôfago e que seu tratamento pela esofagectomia parcial e manejo alimentar é eficiente permitindo a completa recuperação do animal