https://repositorio.ufu.br/handle/123456789/5160 Sun, 20 Sep 2026 22:13:15 GMT 2026-09-20T22:13:15Z https://repositorio.ufu.br:443/retrieve/b23f12e1-21dd-4c9f-9dfa-a54c16775eee/ https://repositorio.ufu.br/handle/123456789/5160 https://repositorio.ufu.br/handle/123456789/50335 Title: Entre retornos e permanência: Em busca dos sentidos da escolarização nas narrativas de estudantes da EJA noturna Abstract: This undergraduate thesis investigates the meanings attributed to schooling by students of Youth and Adult Education (EJA) in the night shift, through the analysis of their life narratives. The research is based on a qualitative and narrative approach, understanding that the construction and narration of stories is a way for subjects to organize and produce meanings about their experiences, articulating time, memory, and sense. The study used an online form and narrative interviews with night-shift EJA students, whose accounts were analyzed based on emerging categories. The results show that the narratives reveal trajectories marked by ruptures, returns, and challenges, but also by expectations of personal, professional, and social transformation. Participants attribute to EJA meanings associated with self-esteem, opportunity, welcoming, and resilience, highlighting the importance of night school for educational continuity amidst work routines. Therefore, we consider that listening to these narratives broadens the understanding of permanence and the meaning of education for young and adult workers, reinforcing the need for pedagogical practices sensitive to their realities and identities. Mon, 16 Mar 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/50335 2026-03-16T00:00:00Z https://repositorio.ufu.br/handle/123456789/50199 Title: Seasonality and extrafloral nectaries shape plant–spider networks Abstract: Extrafloral nectaries (EFNs) are key plant traits mediating multitrophic interactions, yettheir role in structuring plant–spider communities at the network level remains poorlyunderstood. Here, we provide the first empirical network analysis of plant–spider interactionsin the Brazilian Cerrado, evaluating how EFNs and climatic seasonality shape interactionarchitecture and community composition. From October 2020 to September 2021, wequantified spider occurrences on flowering plants with and without EFNs across dry and rainyseasons and constructed quantitative bipartite interaction networks. We analyzed connectance,nestedness, modularity, and specialization, comparing observed values against null modelexpectations. Plant–spider networks exhibited highly non-random structures, with EFN-bearingplants promoting lower specialization and significant modularity across seasons. Contrary toexpectations, connectance was higher during the dry season, while null models revealed thatbiological constraints limited interaction realization even under high resource availability.Seasonal shifts strongly altered network topology but did not affect spider species composition,which remained stable across plant types and seasons. Our results indicate that EFNs act asstructural hubs that reorganize interaction patterns without driving species turnover,highlighting the importance of facultative interactions and behavioral flexibility in maintainingcommunity stability in seasonal savanna ecosystems. Wed, 29 Jul 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/50199 2026-07-29T00:00:00Z https://repositorio.ufu.br/handle/123456789/50195 Title: Tendências evolutivas no androceu de Melastomataceae: estudos morfológicos e anatômicos dos estames e anteras em gêneros de Melastomeae Abstract: Members of Melastomataceae family usually have actinomorphic and bisexual flowers. The most important pollinator of the plants of this family is female bees which are able to vibrate its poricidal anthers and remove pollen, although there are spontaneous self-pollination species and also apomitic species. In addition to this diversity of reproductive systems, variations throughout the development of the anther wall can take place, ensuing in diversification of parietal layer composition. However, most studies have focused on individuals of the Miconieae tribe; hence there is a necessity to look into these variations in other tribes, specially the most representative in Brazil among them, the Melastomeae. Thus, an objective of this study was to describe the morphology and anatomical structure of the stamens in different Melastomeae genera: Acisanthera P.Browne (2 sp.), Comolia DC. (2 sp.), Poteranthera Bong. (1 sp.), Siphanthera Pohl (2 sp.) and Tibouchina Aubl. (5 sp.), attempting to identify and understand, from an evolutionary point of view, the changes found apart from pointing out some features that can assist in the delimitation of these genera and tribes (Chapter 1). This research also aimed to study the floral biology and reproductive system of the smallest species of Melastomataceae known so far, Poteranthera pusilla Bong (Chapter 2). The morphological and anatomical studies, including the vascularization of stamens, were performed according to the usual techniques of plant anatomy; and P. pusilla reproductive biology was studied under control pollination, pollen viability and pollen tube growth. The morphological results have shown that most of the studied species has dimorphic androecium containing ten stamens, which has antesepal stamens larger than antepetals, as well as other members of Melastomeae. But some species have eight stamens of which the four antepetals may be reduced to staminodes, such as S. gracillima. Another modification that has been found is the total loss of one of the cycles of stamens which happens in P. pusilla. During the study about the development of the anther wall, the monocotyledon type was identified on A. genliseoides, A. quadrata, S. foliosa, S. gracillima and T. villosissima and variations of the monocotyledon type have been ascertained on C. lanceiflora, C. sertularia, P. pusilla, T. candolleana, T. herbacea, T. heteromalla and T. stenocarpa. During the whole of microsporogenesis, of all species, the parietal layer of the anther consists of epidermis, endothecium, middle layer and tapetum, differing only in the number of middle layers. At the stage of anthesis just the epidermis is relentless, except for Comolia specieis that also exhibit part of the endothecium. In the course of the vascularization analysis, the trace bundles are larger on antesepals stamens and may be absent on the reduced antepetals, as in A. genliseoides and S. foliosa. These morphological and anatomical studies of the stamens and anthers support the available information up to now about an evolutionary trend towards decreasing the size and number of stamens in Melastomataceae. This decrease, which is apparent on the morphology and the anatomy of anthers and vascularization of stamens, seems to occur separately within each genus and shall be related to a sort of pollinator. The study of reproductive biology has shown some morphological characteristics in P. pusilla that allow spontaneous self-pollination, such as large pores and the arrangement of the stamens of the flower at anthesis. It can be concluded that P. pusilla is self-compatible and that spontaneous self-pollination happens due to the large pore which faces the stigma at anthesis. It is also remarkable, in this species, the independence of biotic factors during pollination and probably over fruits spreading, which culminate in a highly adapted species to survive in environments with scarce pollinators. Considering this scenario, we conclude that all androecium and anthers variations of these species seem to be associated with a general tendency of pollinators in this family, aforementioned for representatives of the Miconieae tribe. Mon, 24 Feb 2014 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/50195 2014-02-24T00:00:00Z https://repositorio.ufu.br/handle/123456789/50185 Title: Polinização de Peixotoa tomentosa A. Juss. (Malpighiaceae), como as estruturas florais condicionam a visitação biótica e o transporte polínico Abstract: Plant populations have undergone substantial changes over time due to anthropogenic and climatic factors. Angiosperms are the largest and most diverse plant group and have, accordingly, established extensive mutualistic interactions with insects. In the Cerrado, plant–insect interactions are highly diverse, and among the most relevant in this context are those involving the family Malpighiaceae, one of the 11 botanical families that produce floral oils. We investigated how floral morphology in one of its species, Peixotoa tomentosa A. Juss., affects bee visitation and fruit set, considering its capacity to produce fruit through agamospermy. The study was conducted in a Cerrado fragment at Itororó Park Club (formerly Clube de Caça e Pesca Itororó), in Uberlândia, Minas Gerais, Brazil. We assessed floral attractiveness to small-, medium-, and large-bodied bees and the resulting fruit set, and tested five controlled pollination treatments. Visitation rate was lower than expected, with only 10 bees recorded over 15 hours of observation, which limited the evaluation of the floral attraction and fruit set hypotheses; this did not, however, preclude comparison among pollination treatments, whose fruit set values were statistically similar, indicating reproductive capacity even in the absence of pollen grains. Although the adhesive function of staminodes has previously been reported in other plant families, our study provides the first confirmation of this function within Malpighiaceae, showing that the substance exuded by the staminodes significantly increases pollen grain adherence to the transport vector and, subsequently, to the stigmas. Studies on the chemical composition of the staminodal secretion may help elucidate its adhesive function. These results suggest a relationship between low pollinator frequency, prior anthropogenic disturbance (e.g., the 2021 fire), and reduced fruit set, reinforcing the importance of long-term studies on pollination in the Cerrado. Thu, 23 Jul 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/50185 2026-07-23T00:00:00Z