http://repositorio.ufc.br/handle/riufc/58 Wed, 08 Apr 2026 21:35:31 GMT 2026-04-08T21:35:31Z https://repositorio.ufc.br:443/ri/retrieve/71a31dac-d208-4bb7-ad14-1f3719846326/comunidade_CC-RI-moldurado.jpg http://repositorio.ufc.br/handle/riufc/58 http://repositorio.ufc.br/handle/riufc/85601 Título: Papel funcional da família de enzimas glicolato oxidase (GOX) e catalase (CAT) em feijão-caupi (Vigna unguiculata [L.] Walp.) na resposta ao Cowpea Severe Mosaic Virus Autor(es): Bezerra, Victor Breno Faustino Abstract: With the increase in food shortages and nutritional deficiencies, the choice of alternative crops with relevant characteristics is important. Vigna unguiculata L. is therefore a crop of great interest. However, cowpeas are still susceptible to some pathogens, such as the CowPea Severe Mosaic Virus (CPSMV). Under adverse conditions, such as infection by pathogens, one of the initial mechanisms for the stress response involves the production of reactive oxygen species. One of these molecules is hydrogen peroxide, which has its highest production rate related to Glycolate Oxidase (GOX), an enzyme in the photorespiration process, but like all reactive species, its production and consumption must be finely balanced, so there is the peroxisomal enzyme Catalase (CAT), responsible for this control during a stress phenomenon. The aim of this study was therefore to analyse the expression of GOX and CAT gene copies, at transcript and activity level, in response to CPSMV. To this end, the plant specimens were inoculated with CPSMV at three time points (16 hours, 48 hours and 144 hours). Analyses of catalase enzyme activity showed differences between the cultivars only in the initial hours (16h), in the control conditions of inoculated Pitiúba and Mock, possibly related to the initial response to the pathogen. In addition, analyses using DAB (3,3'-Diaminobenzidine) staining, MDA (Malonaldehyde) and peroxide content were used to determine the degree of oxidative stress, again with differences only between Pitiúba Mock and inoculated at 16 and 48 hours. In addition, the expression data showed differences mainly in the VuGOX1 gene in the Macaíbo cultivar, whose expression was induced during infection compared to the Mock. While VuGOX2 was the gene with the highest abundance at transcript level, showing differences between the cultivars at times of 16 and 144h, with reduced expression in inoculated Pitiúba compared to Mock 144h. Analysis of cis-elements showed regions that corroborate points raised in the discussion, mainly related to the pathogen response route and the synthesis of salicylic acid (SA). Thus, it is hoped that the results found will help breeding programmes and understanding of the resistance phenomenon. Tipo: Dissertação Wed, 01 Jan 2025 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/85601 2025-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/85588 Título: Estudo das propriedades vibracionais das perovskitas híbridas de azida Autor(es): Hora, Renata Rodrigues da Abstract: Recently, perovskite-type organic-inorganic hybrid compounds have attracted considerable interest due to their structural versatility, which allows for the manifestation of various interesting physical properties for application in devices. These materials exhibit a wide range of functionalities, including photovoltaic, ferroelectric, and multiferroic properties. In this thesis, we used the slow evaporation method to obtain three perovskite-type hybrid compounds, [(CH3)3N][Mn(N3)3] (TrMAMnN3), [(CH3)2NH][Mn(N3)3] (DMAMnN3), [(CH3)2NH]2[CoNa(N3)6], whose structural, thermal, and vibrational properties were investigated as a function of temperature. In the case of the compound [(CH3)3NH][Mn(N3)3], we analyzed in detail the wavenumber and full-width half-height (FWHM) of lattice modes and internal modes of the NC3 skeleton, N3– and CH3 molecular groups. In general, the modes exhibited unusual behavior during phase transitions, including discontinuity in phonon wavenumber, bandwidth, and unconventional changes due to temperature variation. Furthermore, we used differential scanning calorimetry (DSC) to confirm a subtle monoclinic-to-monoclinic phase transition (P21/c →C2/c) around 330 K; and the phase transition to trigonal structure (R m) above 359 K, whose associated entropy variation becomes |ΔS| ~ 22.3 J·kg⁻¹ K⁻¹ and exhibits a barocaloric coefficient (BC) |δTt/δP| ~ 3.17 K kbar⁻¹. For DMAMnN₃, a first-order structural transition from the orthorhombic phase (Cmca) to the monoclinic phase (P2₁) was identified, with an entropy variation of ~37.2 J·kg⁻¹·K⁻¹ and a barocaloric coefficient of ~2.94 K·kbar⁻¹, in agreement with the Clausius-Clapeyron method. Room-temperature Fourier transform infrared (FTIR) reflectivity spectra identified polar phonons and their damping coefficients. Minimal contributions from the DMA+ mode were observed in the intrinsic dielectric constant (~4.3). An anomaly was observed at ~85 K, indicating a transition from the paramagnetic to the antiferromagnetic state (PM-AFM). Finally, we present a new compound obtained through the slow evaporation synthesis [(CH3)2NH]2[CoNa(N3)6], where single-crystal XRD measurements resolved the material's structure, showing that up to 100 K the structure does not exhibit a structural phase transition. A room-temperature Raman spectrum was also obtained, and mode assignment was performed. Tipo: Tese Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/85588 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/85562 Título: Uma proposta metodológica para distribuição de recursos do PDDE a partir de critérios de eficiência e necessidade com aplicação de análise envoltória de dados Autor(es): Fossile, Marcelo Gomes Abstract: This study proposes a methodology for the allocation of resources from the Programa Dinheiro Direto na Escola (PDDE) among Brazilian states, guided by criteria of technical efficiency and need, using Data Envelopment Analysis (DEA) as a supporting tool for measuring relative performance. The analysis considers a financial input and two sets of outputs: structural variables expressed in absolute values, which reflect the installed capacity of education systems, and educational indicators expressed as ratios, which capture performance outcomes. The models were implemented in Python using the Pyomo library and solved with the GLPK solver. Based on the efficiency scores, the potential savings associated with projecting units onto the efficient frontier are estimated and used as a reference for defining the amount of resources to be allocated, which may be adjusted according to criteria established by public managers. In the subsequent stage, a parametric model is developed that combines relative efficiency with a need index composed of eight indicators, weighted by the parameter λ ∈ [0,1], allowing the simulation of scenarios ranging from efficiency-oriented allocation to greater emphasis on vulnerability. The results reveal distinct territorial patterns in both efficiency and levels of need, highlighting how different weighting choices between these two dimensions affect the final allocation of resources. The proposed approach provides a transparent quantitative tool to support public policy decisions aimed at optimizing federal investments in basic education. Tipo: Dissertação Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/85562 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/85557 Título: Plasticidade de cajueiros à baixa disponibilidade hídrica no solo: mecanismos fisiológicos, metabólicos e epigenéticos Autor(es): Costa, Igor Rafael Sousa Abstract: The cashew tree (Anacardium occidentale L.) is a highly relevant species for the Brazilian semi-arid region, which it develops under environmental conditions characterized by a combination of abiotic stresses, such as high irradiance, salinity, water deficit, and high temperatures. Adaptation to this environment involves physiological and molecular mechanisms that regulate acclimation to environmental stress. This thesis investigated the processes that support tolerance and the ability to adjust to water deficit in the cashew tree, integrating different biological levels to identify functional patterns associated with adaptation. In the first chapter, physiological, biochemical, metabolic, and molecular responses were evaluated in two contrasting cashew genotypes subjected to successive cycles of water deficit followed by rehydration. The BRS 226 genotype showed greater osmotic stability during stress, more efficient photosynthetic recovery, and greater functional adjustment capacity after repeated drought exposures. The regulation of the redox state and the progressive activation of the antioxidant system indicated physiological adjustment to recurrent stress, accompanied by extensive metabolic reorganization, with modulation of compounds associated with energy metabolism and cellular adaptation. In contrast, the CCP 09 genotype showed more restricted physiological and metabolic responses, with less recovery capacity after successive stress cycles. The differential modulation of the expression of genes associated with the stress response and the activation of markers re ated to DNA methylation during recovery suggest the participation of epigenetic mechanisms in the physiological reorganization induced by drought cycles. Taken together, the results indicate that the differential tolerance between genotypes is associated with the coordination between physiological, metabolic, and molecular adjustments in response to recurrent water stress. The second chapter investigated the epigenetic dynamics associated with a single water deficit event followed by recovery in cashew seedlings, using enzymatic sequencing of DNA methylation. Although the overall methylation profile remained relatively stable across water conditions, extensive local alterations were detected throughout the genome, indicating epigenetic reorganization associated with the plant's physiological state. These modifications were related to distinct regulatory and metabolic processes between stress and recovery phases, suggesting that DNA methylation participates in the functional modulation of the water response. The observed epigenetic variations accompanied changes in photosynthetic performance and the expression of marker genes, highlighting an association between epigenetic modulation and physiological adjustments to water deficit. In an integrated manner, the results demonstrate that the cashew tree's response to water deficit involves coordination between physiological, metabolic, and epigenetic processes that contribute to functional adjustments of metabolism and the photosynthetic apparatus during stress and recovery. These findings broaden the understanding of the regulatory mechanisms associated with the water response in tropical perennial species and provide a basis for the development of genetic improvement strategies and adaptive management under scenarios of greater climate variability. Tipo: Tese Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/85557 2026-01-01T00:00:00Z