Principais Coleções do Repositório
Submissões Recentes
dissertação
Mitigação de estresse hídrico em mudas de Eucalyptus urophylla × E. grandis pela aplicação de regulador de crescimento
(Universidade Federal de Lavras, 2026-07-24) Alberto, Flávio Juízo; Brondani, Gilvano Ebling; Leite, Douglas Machado; Faria, Júlio Cézar Tannure; Leite, Douglas Machado
Eucalyptus is one of the most important forest species in Brazil due to its high productivity and economic and environmental importance. However, water deficit is one of the main factors limiting seedling growth and survival. In this context, growth regulators such as paclobutrazol (PBZ) have been investigated due to their ability to induce morphological, physiological, and biochemical adjustments associated with stress tolerance. This study aimed to evaluate the effects of PBZ application on morphological, physiological, biochemical, nutritional, and survival responses of clonal seedlings of Eucalyptus urophylla × Eucalyptus grandis under different water availability conditions. The experiment was conducted in a greenhouse using a randomized block design with a factorial arrangement consisting of six soil water levels (0, 10, 20, 40, 60, and 80% of field capacity) and two PBZ treatments (with and without application). Growth parameters, stress intensity, photosynthetic pigments, osmoprotective compounds, leaf nutrient concentrations, and seedling survival were evaluated. PBZ application increased seedling survival under moderate water deficit conditions, particularly at 20 and 40% of field capacity, and delayed the progression of stress symptoms after irrigation suspension. The regulator reduced shoot height and leaf expansion, altered leaf number, and increased the Dickson Quality Index. Root dry biomass was enhanced mainly under moderate water deficit conditions. Regarding photosynthetic pigments, PBZ contributed to the maintenance of total chlorophyll under severe water stress, while chlorophyll a content was reduced regardless of water availability; carotenoid levels were not affected by PBZ application. Biochemical analyses showed that PBZ promoted the accumulation of proline, sucrose, and total soluble sugars under severe water restriction, whereas soluble protein content was reduced by PBZ. Leaf nutritional status was modulated by PBZ, with specific changes in macro- and micronutrient concentrations, including increased calcium, magnesium, and some micronutrients, as well as reduced sodium accumulation under certain water conditions. Overall, PBZ promoted physiological and biochemical adjustments that contributed to the acclimation responses of Eucalyptus seedlings to water deficit.
dissertação
Predictive modeling for prediction of technological maturity and microterroir zones of grapevines in subtropical region in Brazil
(Universidade Federal de Lavras, 2026-07-10) Barbosa, Bernardo Siqueira Costa; Pio, Rafael; Peche, Pedro Maranha; Peche, Pedro Maranha; Pio, Leila Aparecida Salles; Moura, Pedro Henrique Abreu
Determining grape quality through conventional methods is a destructive and costly laboratory process that limits the understanding of spatial and temporal variability within vineyards. This study proposes to validate non-destructive predictive approaches, grounded in precision viticulture and machine learning, for monitoring technological maturity and delineating microterroir zones. The research focuses on the double-pruning regime (winter wine production) in subtropical regions of Brazil, investigated under two complementary perspectives of scale and data acquisition. In the first study, the focus was on interseasonal macroprediction (2024–2025) and microterroir zoning in a subtropical area. The integration of Growing Degree-Days (GDD) and Vegetation Indices (VIs) revealed the Random Forest algorithm as the most robust for the temporal prediction of Soluble Solids (SS, R² = 0.73) and Titratable Acidity (TA, R² = 0.71), although pH modeling exhibited performance degradation on independent datasets. Concurrently, K-Means unsupervised clustering integrated multiyear canopy vigor (via Google Earth Engine), topography, and soil proxies to delineate microterroir zones, achieving high efficacy in the stratification of macrophysiological traits (Variance Reduction of 33.62% for chlorophyll b). In the second study, a high-spatialresolution predictive framework was developed for the same management system. The fusion of agrometeorological data with multispectral imagery acquired by an Unmanned Aerial Vehicle (UAV) significantly outperformed the isolated use of VIs. The XGBoost algorithm achieved the highest accuracy (R² = 0.89 for SS; R² = 0.77 for TA), demonstrating that GDD and cultivar determine the primary maturation dynamics, while VIs capture the refinement of spatial variability in vigor at a sub-metric scale. In summary, it is concluded that integrating climatic data with remote sensing platforms (orbital and aerial) provides a robust analytical framework for precision viticulture in double-pruning areas, optimizing the assessment of technological maturity, the management of microterroir zones, and harvest decisions.
Artigo
Antimicrobial and antioxidant activity of apricot (Mimusopsis comersonii) phenolic-rich extract and its application as an edible coating for fresh-cut vegetable preservation
(2022-10-21) Lima, Emília Maria França; Matsumura, Caroline Harumi Silva; Silva, Geovana Luísa da; Patrocínio, Isabela Cristina Soares; Santos, Catarina Angeli; Pereira, Patrícia Aparecida Pimenta; Hassimotto, Neuza Mariko Aymoto; Pinto, Uelinton Manoel; Cunha, Luciana Rodrigues da
Edible coatings have several advantages in preserving foods, such as avoiding water loss, controlling microbial growth, and reducing the need for preservatives added directly to the product. Antimicrobial action can be obtained by adding antimicrobial substances including phenolic compounds commonly found in plant extracts. This study evaluated the phenolic compounds content, antioxidant and antimicrobial activity of pulp, and seed extracts of Mimusopsis comersonii (popularly known in Brazil as abrico), besides the phenolic compounds were identified and quantified in the pulp extract. Edible coatings were incorporated with pulp extract in order to evaluate the preservation of minimally processed apples and baroa potatoes against foodborne bacteria, and enzymatic browning was also determined. Myricetin-3-glucoside, quercetin-3-glucoside, and kaempferol-3-glucoside were identified as major flavonoids in the apricot pulp extract. The seed and pulp extracts inhibited all tested microorganisms, especially Staphylococcus aureus and Salmonella Typhimurium. Edible coatings added with 9% of phenolic extract showed in vitro antimicrobial activity, in addition to being effective in preventing enzymatic browning in minimally processed apples and baroa potatoes for up to 15 days of storage. They were also effective in reducing up to 2 log CFU/g of aerobic mesophiles after 15 days of storage for apples, even though no microbial inhibition in baroa potatoes was observed under the same conditions. The addition of pulp phenolic extract in edible coatings proved to be an alternative in the preservation of apples and in the antibrowning activity of minimally processed baroa potatoes.
Artigo
Qualificação à distância para promoção da alimentação adequada e saudável no Sistema Único de Saúde
(2022-10-01) Silva, Angélica Ribeiro e; Lopes, Mariana Souza; Ferreira, Nathália Luíza; Freitas, Patrícia Pinheiro de; Lopes, Aline Cristine Souza
Introduction: Actions to promote adequate and healthy food (PAAS in Portuguese) have been gaining space on public policy agendas due to the urgency of caringfor non-communicable chronic diseases. For the implementation of these actions in daily work, health professionals must be qualified, aiming at their empowerment and autonomy.Objective: To evaluate professional qualification activity for the development of collective actions of PAAS in Primary Health Care (PHC).Methods: Prospective and descriptive study conducted to evaluate professional qualifications offered at a distance, with a workload of 30 hours. Three classes were offered to PHC professionals from all Brazilian macro-regions. Quantitativeonline questionnaires were usedand applied immediately after completion of the course and after three months. Results were stratified by country macro-region and course completion.Results: Of the 3,957 enrolled, about a thousand professionals completed the course (completion rate: 25.3%), most of them women and registered dietitian. Professional qualification was considered very relevant for professional practice (99.2%) and with adequate methodological quality (99.6%). The main obstacle for not completing the course was the lack of time (78.1%). Most of the non-graduates were older, nurses, with more time working in the SUS, those who accessed the course via cell phone, and previous participation in professionalqualification on the subject.Conclusions: Professional qualification was able to develop skills and abilities to conduct collective PAAS actions among health professionals. However, strategies need to be proposed to increase the completion rate.
dissertação
A crise do conhecimento nas Confissões de Agostinho
(Universidade Federal de Lavras, 2026-09-02) Oliveira, Cesar Augusto Santos; Sousa, Meline Costa; Di Silva, Maurizio Filippo; Loque, Flavio Fontenelle
This dissertation investigates the conceptualization and unfolding of the crisis of knowledge in the intellectual and epistemological itinerary of Augustine of Hippo, taking the retrospective weaving contained in the work Confessions as its central hermeneutical landmark. The scope of the work consists of analyzing how the collapse of the materialistic representational model of Manichaeism and the subsequent tension with the skepticism of the New Academy led the author to a profound reformulation of human cognitive capacity, the overcoming of which and access to Truth became attainable through the harmonization between rational inquiry and the authority of faith. Methodologically, the research delimits the crisis from a strictly epistemological perspective and contextualized within Late Antiquity, moving away from vague psychological or existential categorizations. In the first chapter, which analyzes Book V, it is demonstrated how Manichaean cosmological inconsistencies in the face of empirical astronomical data dragged Augustine toward academic systematic doubt, operating as a negative purification of the mind that prepared the ground for the rehabilitation of belief by testimony and the legitimation of the Scriptures under the mediation of Ambrose of Milan. In the second chapter, the object of analysis of which is Book VII, the impact of reading the Neoplatonic books is deepened, explaining that, although Neoplatonism provided the metaphysical apparatus necessary to dematerialize the conception of God and to equate evil under the status of the privation of good, pagan philosophical reason proved to be soteriologically insufficient, demanding the introduction of the doctrine of divine medicinal Grace to heal and unify a volitional faculty split by the weight of habits. The third chapter crowns the investigation by scrutinizing the dynamic structure of memory in Book X, showing that the narrative transition preserves autobiographical value by shifting the object of examination from sensible things to supersensible realities. The mnemonic palace is mapped as the intelligible space of self-consciousness, and the paradox of forgetfulness is deciphered as the theological trigger that breaks solipsistic isolation, proving that the soul, too narrow to contain its own immensity, depends on the illumination of the Word as ratio cognoscendi. Consequently, the results of this research reiterate that the resolution of the Augustinian epistemological crisis shifts philosophy into the orbit of an eminently practical discipline of beatitude, consolidating the thesis that the authentic constitution of knowledge merges with affective rest alongside the Supreme Good and the attainment of the happy life (beata vita).