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Boa postura analítica e Gevrey da “boa” equação de Boussinesq
(Universidade Federal de São Carlos, 2021-03-11) Figueira, Renata de Oliveira; Barostichi, Rafael Fernando; https://lattes.cnpq.br/3582461114222090; https://lattes.cnpq.br/0208377857169816
In both the line and the circle, we shall to prove that the Cauchy problem for the ``good'' Boussinesq equation is locally well-posed in a class of Gevrey functions, which includes a class of analytic functions that can be extended holomorphically in a symmetric strip of the complex plane around the x-axis. Additionally, information about the regularity of the solution in the time variable shall be provided.
Avaliação do lasso e métodos alternativos em modelos de regressão logística
(Universidade Federal de São Carlos, 2021-03-11) Alcântara Junior, Gilberto Pereira de; Pereira, Gustavo Henrique de Araujo; https://lattes.cnpq.br/4536501674241631; https://lattes.cnpq.br/1598281979751453
Logistic regression has always been an important tool not only in the area of statistics, but also in several other areas such as economic, biological and medical. In many of these areas it is common to encounter problems of high dimensionality, in which the number of covariates to be tested is greater than the sample size. Classic estimation methods present certain problems in high dimensionality. One of the ways to solve this problem is the estimation by methods of penalty, as the lasso proposed by Tibshirani (1996). Despite the many works done on the application of lasso in the logistic regression model, none of them presents a complete study of simulation of the method's prediction performance using some traditional measure of performance evaluation. There are also no studies in the literature that compare the performance of other possible combinations made from lasso, such as lasso to select covariates and estimation via maximum likelihood, or selection via stepwise and estimation via lasso. In this work an extensive simulation study is presented under several scenarios created in order to study and compare the performance of the lasso and 3 other techniques combined in the logistic regression model. Several examples of applications in which the logistic model can be used were also studied and analyzed. Through the results obtained both by the simulations and by the applications, in relation to the predictive power, it was possible to verify that the lasso stood out or had similar performance to the other methods in all the presented scenarios. Regarding the comparison of the adjusted model with the real one, none of the methods considered stands out in all scenarios and in relation to all aspects analyzed.
Perfil químico e dinâmica espacial e temporal de flavonoides de soja [Glycine Max (L.) Merr.]
(Universidade Federal de São Carlos, 2021-03-11) Costa, Josicleia Oliveira; Wouters, Felipe Christoff; https://lattes.cnpq.br/4392349445398645; https://lattes.cnpq.br/9469985968777626
The soybean (Glycine max) is a legume species originally from China, belonging to the Fabaceae family. This crop is exposed throughout its cycle to attack by different species of insect pests, which can affect the plant development and, consequently, its productivity. Some studies classify flavonoids as relevant constituents in the defense of soybean against injury to herbivores. Despite the potential role of flavonoids against herbivores, little is known about the variability and spatial and temporal allocation of these defenses in soybean leaves and throughout its developmental stages. Therefore, this work aims to investigate the chemical profile of a commercial soybean cultivar, comparing the flavonoid profiles from different leaves over different developmental stages. Conventional soybean seeds BRS 284 were germinated and grown in a greenhouse. Samples of old, young and immature leaves from emergency stage (VC), cotyledon stage (VE), vegetative stages 1, 2, 3, 4 and 5 (V1 to V5), and reproductive stages 1 and 2 (R1 and R2) were collected and extracted in 1:1 (v/v) methanol: water, and the extracts were analyzed by LC- MS. The main flavonoids of soybean leaves were identified by mass spectra and relatively quantified. During the developmental stages, higher levels of kaempferol mono, di and isomeric triglycerides found in immature and young leaves were found. The initial stages, emergency vegetative and coethylene vegetative, showed higher concentrations of isoflavones such as daidzein, genistein, glycitein and their glycoconjugates, which are more abundant in old leaves. The chemical profile and allocation dynamics of the studied flavonoids provide information on the different strategies used by the plant to allocate its resources, demonstrating that leaves of different ages differ in their composition, possibly according to their physiological and ecological context. Therefore, evidence of the role of constitutive flavonoids in the defense mechanism of soy will help in the development of methods that can contribute to agricultural productivity, adaptability and resistance to various stressors in a more sustainable way.
Diversidade taxonômica e funcional das aves da Mata Atlântica sob influência da maior metrópole do hemisfério sul, São Paulo, Brasil
(Universidade Federal de São Carlos, 2021-03-11) Melo, Marcos Antônio; Piratelli, Augusto João; https://lattes.cnpq.br/4747322084219058; https://lattes.cnpq.br/2184880129329313
Urbanization creates one of the most irreversible forms of land use and occupation. Commonly, urbanization results in species losses and functional homogenization of bird communities, thus affecting the functioning of ecosystems. The objective of this thesis was to understand, in different ways, how the urbanization of São Paulo's megacity influences bird communities and ecological processes. In the first chapter, I evaluated how urban parks and residential areas contribute to the maintenance of bird communities and diversity of ecosystem functions compared to large forest fragments (source areas). The results show the need to maintain large areas of native forest on the city limits to preserve the rich avifauna and maintenance of ecosystem functioning. Urban parks next (<10 km) to the source areas show greater bird’s functional diversity, but not taxonomic, than those far away (> 10 km). Moreover, vegetation complexity can mitigate the impact of urbanization in urban habitats. In the second chapter, I evaluated how bird guilds and the entire community can be influenced by biotic-abiotic characteristics in São Paulo’s urban green areas. The results indicated the importance of large green areas with high shrub cover to shelter rich regional birdlife. On the other hand, small green areas should mitigate the possible negative impacts on birds related to glass panels, vehicle traffic and the presence of humans, dogs and cats, which can systematically eliminate functional groups and decrease the provision of ecosystem services provided by specialist guilds (frugivorous-nectarivorous and insectivorous) and also generalists. In the third chapter, I tested how species, functional groups and functional diversity indices respond to the amount of vegetation (normalized difference vegetation index, NDVI) and red clay roofs (RCR, a potential bird nesting site) in residential areas of the São Paulo megacity. The results indicate that combinations between high coverage of NDVI (> 0.5) and RCR can increase the occurrence of species and ecological functions in Neotropical cities. These results can guide environmental management measures and public policies aimed at the conservation of biodiversity and its ecosystem services (essential to human well-being) in different urban habitats.