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Biology subjects

Oliveira, M. B.

Publications and source records attributed to Oliveira, M. B..

2 recordsLinked to original sources

Integration of Deep-Learning and Species Distribution Models for Classification of Animal Species of the Brazilian Fauna

The automated classification of animals from photos is important in ecology and conservation biology for organizing and understanding the immense diversity of species, as well as facilitating effective conservation and management practices. It is equally important for disease surveillance systems, allowing prompt detection of anomalies in species distributions and boosting citizen-scientist platforms by making user-reported data more accurate and convenient. Image classification uses photos and can also rely on the geographical locations of animals to improve performance. While image classification models have difficulties in classifying low-quality images, unbalanced datasets, and with a small number of images, species distribution models have difficulty in classifying species that coexist in a given region. We propose here strategies for combining image classification models based on deep neural networks with species distribution models using genetic algorithms. The proposal is applied to a real-world dataset comprising fifteen classes of animals from the Brazilian fauna obtained from Fiocruzs citizen-scientist Wildlife Health Information System (SISS-Geo). The SISS-Geo photos portray the reality of animals in their environments, with varying quality, and pose numerous difficulties for classification. Experimental results demonstrate that the proposed integration consistently outperforms standalone models. While individual SDMs achieve Top-1 accuracies of 27.79% (MaxEnt) and 31.76% (Bioclim), and CNN-based classifiers reach 58.17% with ResNet50 and 64.13% with ResNet-152, the hybrid strategies yield substantial improvements. The genetic algorithm-based integration with a single global weight achieves up to 67.96% Top-1 accuracy, whereas the class-specific integration using fifteen parameters attains the best overall performance, reaching 69.03%.

ecology↗

Engineering Controlled Microporosity in Liquid-Core Soft Compartments via Compositional Tuning of Aqueous Immiscible Systems for Facilitated Cell Migration

The processing of materials at aqueous interfaces has enabled the generation of compartmentalization structures with broad biomedical interest. Controlling the porous structure of soft materials to create micro-sized pores that enable cell migration is crucial for tissue development and regeneration. This work presents liquid-core soft compartments formed via interfacial polyelectrolyte complexation between alginate and {varepsilon}-poly-L-lysine, which membrane physical properties are tailored by adjusting the composition of the prototypical aqueous two-phase system. The additional interfacial dynamics provided by the presence of the immiscible polymer phases promoted the organization of porous architectures in the membrane. Fiber-shaped tubular structures enable adhesion and migration of mesenchymal stem cells to surrounding fibrin matrices and its invasion, behavior that was significantly improved in conditions of higher membrane porosity. While preserving the single-step approach of the established technology, the interfacial materials with tailorable porosity can be processed for applications in tissue engineering and regeneration.

bioengineering↗