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Recomendações funcionais para a descrição de materiais raros em ambientes digitais na perspectiva das tecnologias e princípios Linked Data
(Universidade Federal de São Carlos, 2025-08-29) Cunha, Gabriela Aparecida da; Castro, Fabiano Ferreira de; https://lattes.cnpq.br/7124931056289027; https://orcid.org/0000-0002-8712-2654; https://lattes.cnpq.br/5013785155347994; https://orcid.org/0000-0002-2906-0168; Arakaki, Ana Carolina Simionato; Vidotti, Silvana Aparecida Borsetti Gregorio; https://lattes.cnpq.br/9896600626524397; https://lattes.cnpq.br/7390573927636069; https://orcid.org/0000-0002-0140-9110; https://orcid.org/0000-0002-4216-0374
The digitization of rare cultural heritage materials requires more than simple visual reproduction. It is essential that digitization occurs simultaneously with a detailed description of the object, including data on its production, provenance, and trajectory, ensuring the preservation of its context and historical relevance. Thus, the question arises: how has the description of rare materials in digital environments with Linked Data characteristics been discussed in the scientific literature of Information Science? The objective is to investigate initiatives for describing rare materials in digital environments from the perspective of Linked Data in the scientific literature of Information Science, in order to: a) analyze and present the state of the art on the description of rare materials in digital environments with Linked Data characteristics; b) present the standards for describing rare materials and identify their characteristics; c) map the standards, instruments, and initiatives for describing rare materials and their characteristics; d) present and analyze cases of description of rare materials in digital environments with Linked Data characteristics; e) identify similarities and differences in the structuring, representation, and description of rare materials in digital environments; and f) propose recommendations for the description of rare materials with Linked Data characteristics. The methodology used comprised a Systematic Literature Review and an empirical study. As a result, with the aim of studying the cases, initiatives, and instruments identified in the corpus in question, five general categories were established: Models for the representation and organization of bibliographic and cultural data, Ecosystem of tools and projects for data, Cataloging Tools and Standards, Semantic Resources, Spectrum of Metadata Schemas. The research analyzed 29 articles and identified 18 practical cases that demonstrated the conversion of traditional metadata (such as MARC) to semantic models (such as BIBFRAME) and its enrichment through connection with external controlled vocabularies. Recommendations were proposed for the description of rare materials, suggesting the adoption of flexible models (BIBFRAME), open vocabularies, and Web standards (such as JSON-LD and IIIF) to ensure interoperability and access to cultural heritage.
Síntese e caracterização de complexos de prata(I) com ligantes quelantes doadores N,N, N,O e N,S: avaliação da citotoxicidade e atividade antibacteriana
(Universidade Federal de São Carlos, 2025-08-29) Santos, Josenilton De Jesus; Rocha, Fillipe Vieira; https://lattes.cnpq.br/5841127259122766; https://lattes.cnpq.br/8905293463487217; Rocha, Fillipe Vieira; Forim, Moacir Rossi; Franchi, Silmar José Spinardi; Oliveira, Katia Mara de; Teixeira, Ivo Freitas; https://lattes.cnpq.br/5841127259122766; https://lattes.cnpq.br/1234565160573730; https://lattes.cnpq.br/0328917527382379; https://lattes.cnpq.br/8218994148704667; https://lattes.cnpq.br/9782517948999001
In this work, silver(I) complexes containing heterocyclic ligands from the phenanthroline and (thio)semicarbazone classes were synthesized and characterized to investigate their antitumor and antibacterial properties. The synthesis was carried out homogeneous conditions, yielding products with good yields (60–88%). The complexes were characterized by techniques including infrared spectroscopy (IR), UV-Vis spectroscopy, 1H and 13C NMR, elemental analysis (CHN), and high-resolution mass spectrometry (UHPLC-QTOF-MS). Cytotoxicity assays revealed significant activity of the complexes against tumor cell lines A2780, MDA-MB-231 and A549, with IC50 values ranging from 0.18 to 7.2 μM. Several complexes exhibited selectivity over the non-tumor cell line MRC-5, with selectivity indices (SI) greater than 5, particularly the [Ag(phendione)(scz)]⁺ complex. Additionally, the complexes showed selective inhibitory activity against topoisomerase IIα, without affecting the IIβ isoform, indicating potentially beneficial enzymatic selectivity. Assays performed with the pUC19 plasmid showed no significant DNA cleavage at the tested concentrations. Microbiological tests demonstrated antibacterial activity against Gram-positive strains (S. aureus, S. epidermidis) and Gram-negative strains(E. coli, K. pneumoniae). The [Ag(phendione)(scz)]⁺ complex stood out with minimum inhibitory concentrations (MIC) ranging from 1.95 to 15.6 μg mL-1. The greater susceptibility observed in Gram-positive bacteria may be attributed to the absence of the lipopolysaccharide outer membrane, facilitating access of the complexes to intracellular targets. Regarding anti-Leishmania activity (promastigotes), complexes containing phendiona or batophen exhibited submicromolar EC₅₀ values: 0.2–0.5 μM for L. amazonensis and 0.3 – 0.5 μM for L. braziliensis, with cytotoxicity in RAW 264.7 within 1.6 – 3.8 μM, resulting in selectivity indices (SI) frequently > 8 (up to ~12.7, depending on the system). Taken together, the results identify Ag(I) complexes with N,O/N,S-donor ligands as multifunctional candidates with relevant potency and selectivity, directed interaction with biomolecular targets (topo IIα), and broad activity spectrum (tumors, bacteria, and Leishmania), thereby justifying mechanistic studies and in vivo evaluation.
An obstruction to topological embeddings between generalized manifolds
(Universidade Federal de São Carlos, 2025-08-29) Budtinger, Odete Lara Melo; Santos, Edivaldo Lopes dos; https://lattes.cnpq.br/2167472456497730; https://lattes.cnpq.br/5957304437174421; Saeki, Osamu; Libardi, Alice Kimie Miwa; Santos, Edivaldo Lopes dos; https://lattes.cnpq.br/1510825392356387; https://lattes.cnpq.br/2167472456497730; https://orcid.org/0000-0003-1679-9948
This work presents a study of a certain class of obstructions to the existence of a proper homotopy between a proper continuous map and a proper topological embedding between generalized manifolds, without assuming any smooth structure. Such a class was studied by Carlos Biasi, Janey Daccach, and Osamu Saeki in 1 using generalized manifolds, and in 2 assuming a smooth structure. Using this class, we derive some interesting applications involving Euler classes, Haefliger’s obstruction, self-intersection sets, and real projective spaces.
Leveduras Não-Saccharomyces para produção de etanol em mostos de cana-de-açúcar
(Universidade Federal de São Carlos, 2025-08-29) Lima, Judieldo de Morais; Ceccato-Antonini, Sandra Regina; https://lattes.cnpq.br/7600793543184032; https://lattes.cnpq.br/2742226360127789; Bastos, Reinaldo Gaspar; Perna, Michelle dos Santos Cordeiro; https://lattes.cnpq.br/9329363278429665; https://lattes.cnpq.br/6803429357877935
The main yeast used in the industrial ethanol production process is Saccharomyces cerevisiae. However, non-Saccharomyces yeasts may offer some advantages, such as greater adaptation to the fermentation environment and greater genetic diversity. Alcoholic fermentation is an essential step in fuel ethanol production, where factors such as must composition, process conduction system, and yeast treatment affect process efficiency. Therefore, this study aimed to evaluate the potential of non-Saccharomyces yeasts (Wickerhamomyces anomalus, Meyerozyma guilliermondii, and Scheffersomyces stipitis) for ethanol production from sugarcane musts compared to industrial strains of S. cerevisiae (PE-2 and CAT-1). Initially, the stress tolerance (pH, temperature, glucose, and ethanol concentrations) of the yeasts was evaluated in microplates and spot assays. There was a difference between the yeasts S. cerevisiae CAT-1 and PE-2. Among the non-Saccharomyces, W. anomalus and M. guilliermondii presented tolerance profiles closer to the industrial ones, with W. anomalus being similar to PE-2 and M. guilliermondii to CAT-1. Both non-Saccharomyces strains demonstrated promising characteristics for the ethanol fermentation process under typical industrial stresses. Next, the growth and ethanol yield of the yeasts were evaluated in three different sugarcane-derived musts (molasses, broth, and mixed) at a concentration of 40 g/L total reducing sugar, under agitation, at 30 °C. Molasses promoted an increase in cell number for S. cerevisiae and non-Saccharomyces strains. Strain PE-2 had the highest ethanol yield in 12 h, with little variation between media, while CAT-1 achieved its best yield in broth after 24 h. For S. stipitis and W. anomalus, the best yields occurred in broth, with M. guilliermondii showing the highest growth in molasses, but with similar yields in broth and molasses media. Considering molasses as a medium for cell propagation and fermentation, fermentation tests were performed in a fed-batch system with cell recycling (six cycles) in molasses, also evaluating the effect of treating the cells with sulfuric acid between fermentation cycles. The yeasts S. cerevisiae CAT-1 and M. guilliermondii were selected, and cell viability and fermentation parameters were evaluated. Cell recycling reduced the fermentation rate and viability of both yeasts. For M. guilliermondii, acid treatment decreased viability but maintained yield (50% of theoretical), indicating tolerance to acid stress and a limitation related to its fermentation capacity. For S. cerevisiae CAT-1, acid treatment increased yield, despite reducing viability and budding. M. guilliermondii was not competitive with S. cerevisiae in terms of fermentation yield, although it demonstrated that even with acid treatment and cell recycling, it can maintain cell viability at levels that do not impact its ethanol yield, although much lower than that demonstrated by S. cerevisiae CAT-1.
Modelagem e simulação das etapas de liquefação, sacarificação e fermentação do processo de produção de etanol de milho: estudos para otimização do processo
(Universidade Federal de São Carlos, 2025-08-29) Azevedo, Paulo Gabriel Ferreira de; Cruz, Antonio José Gonçalves da; https://lattes.cnpq.br/1812806190521028; https://orcid.org/0000-0001-6830-9512; https://lattes.cnpq.br/5454599346752237; https://orcid.org/0000-0003-0685-2928; Lima, Alice Medeiros de; Ribeiro, Marcelo Perencin de Arruda; https://lattes.cnpq.br/0038936541518854; https://lattes.cnpq.br/0381402687491195
The use of corn for first-generation ethanol production has been increasing exponentially in Brazil, making the optimization of this process essential to enhance its competitiveness relative to sugarcane. This study models, simulates, and optimizes the liquefaction (L), saccharification (S), and fermentation (F) stages of corn ethanol production, evaluating four process configurations: (i) sequential L, S, and F (LSF), (ii) simultaneous L and S followed by F (SLSF), (iii) separate L with simultaneous S and F (LSSF), and (iv) simultaneous L, S, and F. Mathematical models based on kinetic parameters and literature data were implemented in Python using Google Colaboratory. Uncertainty propagation in the modeling was analyzed using the Monte Carlo Method (10,000 samples) for ethanol concentrations. A plant operating 330 days per year was simulated to estimate the OPEX, with revenues derived from ethanol, corn oil, and DDGS (Dried Distillers Grains with Solubles). The differential evolution method was employed to maximize the annual net profit. Using initial concentrations reported in the literature, the concentrations of the process components were obtained. The highest uncertainty in final ethanol concentration was 7.45%, observed in the SLSF scenario. In terms of optimization, the SSF scenario resulted in the lowest final ethanol concentration (115 g·L⁻¹), the lowest initial starch concentration (239 g·L⁻¹), and the lowest annual net profit (R$ 27 million). Corn accounted for the highest share of the total product cost averaging 73%. DDGS contributed approximately 31% of the total revenue across all scenarios. The sensitivity analysis indicated that variations in the prices of ethanol, corn, and DDGS were the factors that had the greatest impact on the economic indicators of the simulation, with particular emphasis on the SSF scenario, which showed an approximate 600% variation in its annual net balance. Finally, the LSF scenario presented better economic results.
Processos educativos na prática de agricultura urbana das Mulheres do GAU: diálogos na zona leste de São Paulo
(Universidade Federal de São Carlos, 2025-08-29) Ferreira, Larissa; Teixeira, Iraí Maria de Campos; https://lattes.cnpq.br/8274452304759860; https://orcid.org/0000-0003-0307-3443; https://lattes.cnpq.br/5048711015207265; https://orcid.org/0000-0002-4244-326X; Souza Junior, Osmar Moreira de; Santos, Maria Cristina dos; Amaral, Débora Monteiro do; https://lattes.cnpq.br/9176123942671062; https://lattes.cnpq.br/1095065753077001; https://lattes.cnpq.br/8600829409961701; https://orcid.org/0000-0002-2915-5634; https://orcid.org/0000-0003-3130-9433; https://orcid.org/0000-0002-8397-864X
América Latina se caracteriza por diversos intentos de homogeneización de las interpretaciones del mundo, a partir de una lógica dominante que refuerza las estructuras de opresión en la sociedad. En la ciudad de São Paulo, la periferia popular se ha consolidado en una realidad compleja, en la medida en que la planificación urbana no ha respondido a sus demandas en diferentes momentos históricos. Este contexto forma parte de la realidad del colectivo “Mulheres do GAU (Grupo de Agricultura Urbana)”, con el que esta investigación promueve investigaciones y diálogos. En diversos contextos latinoamericanos, la Educación Popular se consolida como praxis educativa, afirmándose en la lucha por la justicia social. En esta perspectiva, la investigación tiene como objetivo comprender y problematizar los procesos educativos revelados por la práctica social de la agricultura urbana realizada por las “Mulheres do GAU”, buscando comprender las contribuciones de estos procesos educativos y cómo las mujeres interpretan el espacio urbano en el que actúan. La investigación es de naturaleza cualitativa y la metodología adoptada es la investigación participante, en la que la convivencia dialógica con el colectivo fue fundamental. La producción de datos se realizó mediante la observación participante, entrevistas semiestructuradas y círculos de conversación. La información fue recopilada e interpretada mediante el análisis de contenido. Los resultados muestran cómo las “Mulheres do GAU”, a través de la agricultura urbana, abordan situaciones límite y deshumanizantes, como la discriminación por motivos de género y raza, la exclusión urbana y los desafíos de ser agricultora en la ciudad. Y así, anuncian diversos procesos educativos, tales como el reconocimiento de sus voces; la ampliación de sus lecturas del mundo; la acogida; la cooperación; los intercambios de conocimientos; la comprensión de cómo lidiar con los conflictos; el sentimiento de pertenencia; el respeto y el amor por la naturaleza, que incluye a los seres humanos y no humanos; el reconocimiento de su trabajo; y cómo sus experiencias de vida constituyen sus formas de ser agricultoras urbanas. También enseñan y aprenden a ser esperanzadas, en el sentido de señalar caminos para hacer las cosas de manera diferente, reivindicando posibilidades de humanización en el trabajo. Con la conclusión de esta investigación, esperamos haber contribuido a la comprensión del universo de la agricultura urbana en la ciudad de São Paulo, practicada por mujeres, en su mayoría negras, profundizando las discusiones sobre las resistencias y las luchas por la calidad de vida en las periferias populares.
A habilidade de escuta ativa empática do Centro de Ciências Exatas e de Tecnologia da Universidade Federal de São Carlos (UFSCar)
(Universidade Federal de São Carlos, 2025-08-29) Inácio, Regilene Vieira; Assis, Karina Gomes de; https://lattes.cnpq.br/4058077286734344; Delai, Ivete; https://lattes.cnpq.br/7054145506480670; https://lattes.cnpq.br/5368445882670617; Paulillo, Luiz Fernando de Oriani e; Teixeira, Rodilon; Assis, Karina Gomes de; https://lattes.cnpq.br/9919942357089937; https://lattes.cnpq.br/2090328410597420; https://lattes.cnpq.br/4058077286734344
This study investigated the level of development of empathic active listening skills among public servants at the Center for Exact Sciences and Technology of the Federal University of São Carlos (CCET/UFSCar). Empathic active listening is a form of listening motivated by the desire to understand others through active engagement, mindfulness, and empathic comprehension. Techniques associated with empathic active listening skills contribute to improved interpersonal communication, making it a required skill for all public servants. In this context, this study aimed to measure the development of empathic active listening skills among public servants at the Center for Exact Sciences and Technology of UFSCar. To answer the research question and understand the measurement of empathic active listening, an integrative literature review was conducted to identify scales for measuring this skill. This study used the Empathic Active Listening Scale (AELS), a selfreport scale comprising three dimensions: detection, processing, and response, along with the listening skills subscale and the opportunity for conversation from the Active Listening Attitude Scale (ALAS). Data were analyzed using exploratory factor analysis. Statistical analysis of the data showed that the CCET/UFSCar presents a moderate level of empathic active listening skills and that the associations between faculty and administrative staff, and between Engineering and Exact Sciences, show the same level of development. The results of this study demonstrated the importance of empathic active listening in the development of interpersonal communication among public servants and the importance of providing training for the development of empathic active listening in the public service. This study contributed to the literature by studying empathic active listening skills among public servants at a Center for Exact Sciences and Technology of a federal university, filling an academic gap. From a practical standpoint, this research presents an empirical diagnosis of the level of development of empathetic active listening skills among public servants. As a technological product, this study developed a conclusive technical report demonstrating the level of development of public servants at CCET/UFSCar.
Educação midiática crítica: combate à desinformação sistêmica na era da economia da atenção e do capitalismo de vigilância
(Universidade Federal de São Carlos, 2025-08-29) Savietto, Daniele; Gomes, Luiz Roberto; https://lattes.cnpq.br/4768579559449929; https://lattes.cnpq.br/4445674595016172; Zuin, Antonio Alvaro Soares; Maia, Ari Fernando; Mill, Daniel Ribeiro Silva; Duci, Juliana Rossi; https://lattes.cnpq.br/5543562307373287; https://lattes.cnpq.br/9075631162602701; https://lattes.cnpq.br/1515286597269486; https://lattes.cnpq.br/3679629908085589
This thesis proposes and substantiates the concept of critical media education as a structural response to systemic disinformation, understood not as an occasional deviation but as a phenomenon that is functional to surveillance capitalism and the instrumental rationality that shapes digital platforms. It differs from notions such as media literacy, educommunication or competence-based models by defending critical media education as a distinct category, anchored in ethical-political foundations and in a critique of informational power structures. Grounded in the Critical Theory of Society (especially Adorno, Horkheimer, Benjamin and Marcuse), the research mobilises the concepts of semiformation and damaged life to explain the vulnerability of subjects to manipulative narratives in a digital environment that reinforces a technical, adaptive and uncritical form of education. The central objective is to analyse, from a theoretical and documentary perspective, how critical formative practices can enable citizens to resist algorithmic logics, the attention economy and symbolic manipulation that permeate the contemporary informational ecosystem. Methodologically, this is a qualitative, theoretical and analytical study, based on a literature review and documentary analysis of public policies and media education programmes in Brazil, Finland and the United Kingdom, with UNESCO’s formulations as an additional reference. The results indicate that, although documents such as the National Common Curricular Base (BNCC) and the Brazilian Media Education Strategy represent important advances, structural challenges remain, such as regional inequalities, fragile federative coordination and gaps in teacher education. The thesis concludes that only a critical media education capable of denaturalising technologies, problematising algorithms and reading disinformation as an expression of the power asymmetries of surveillance capitalism can rebuild the link between education, emancipation and democracy. This requires robust public policies, continuous investment in the critical training of educators and intersectoral coordination that recognises critical media education as a human right and as an instrument of resistance to systemic disinformation.
Condicionantes da participação eleitoral em países africanos de língua oficial portuguesa (2001 a 2023)
(Universidade Federal de São Carlos, 2025-08-29) Eusébio, Cassiano; Casalecchi, Gabriel Avila; https://lattes.cnpq.br/9759794253878555; https://lattes.cnpq.br/9089401461364258; Casalecchi, Gabriel Avila; Braga, Maria do Socorro Sousa; Pessoa Junior, José Raulino Chaves; Souza, Carlos Augusto da Silva; Rocha, Daniel Leonel; https://lattes.cnpq.br/9759794253878555; https://lattes.cnpq.br/2311094074614215; https://lattes.cnpq.br/3204550551936525; https://lattes.cnpq.br/7158504535308341; https://lattes.cnpq.br/4581725419750084
This study analyzes the factors that influence voter turnout in general elections in Portuguese-speaking African countries (PALOP). What are the factors that influence voter turnout in general elections in PALOP countries? Through this research question, we found a theoretical and methodological limitation in comparative studies on the African continent and in PALOP countries specifically. To fill this gap, we reviewed the literature, looking at different micro and macro approaches to electoral participation with reference to African studies. Methodologically, the research uses a series of Afrobarometer surveys combined with institutional and contextual data from PALOP countries. In total, we had 22,747 observations corresponding to the four countries analyzed (Angola, Cape Verde, Mozambique, and São Tomé and Príncipe) referring to nineteen legislative and presidential elections from 2001 to 2023. Using logistic regression and qualitative analysis, we found that individuals who feel close to a political party (party identification) are more likely to vote in PALOP countries. In all countries, low-income individuals were less likely to participate in elections, particularly in Mozambique and, to a lesser extent, Angola. The relationship between institutional trust and participation revealed an ambivalent pattern. In Cape Verde and São Tomé and Príncipe, contexts with greater institutional legitimacy, trust in democracy, the president, and the regime served as a mobilizing factor. In Mozambique and Angola, however, distrust of electoral institutions, such as the CNE, was associated with abstention, especially when accompanied by allegations of fraud or bias. In Angola, the participation of dissatisfied and distrustful voters even exceeded that of satisfied voters—signaling that, in hybrid regimes, voting can be used as an instrument of protest rather than endorsement. Other factors such as age, education, and civic engagement proved to be the main determinants of voter turnout, albeit modulated by different institutional, cultural, and historical contexts in the general elections of the PALOP countries.
Ecotoxicidade de microplásticos de polietileno e nanopartículas de dióxido de titânio isolados e conjugados nas brânquias e fígados de girinos de Aquarana catesbeiana (Shaw, 1802)
(Universidade Federal de São Carlos, 2025-08-29) Fujiwara, Gabriel Hiroshi; Carvalho, Cleoni dos Santos; https://lattes.cnpq.br/7233550271936621; https://lattes.cnpq.br/5331868024785356; Waldman, Walter Ruggeri; Prado, Pierre Ferreira do; https://lattes.cnpq.br/0616238673458322; https://lattes.cnpq.br/1486998769245677
Currently, according to the Second Global Amphibian Assessment, habitat degradation is recognized as one of the main causes of amphibian population decline, with pollution being a major contributing factor to this loss. Among the emerging pollutants that have gained attention—both for their economic relevance and their potential environmental impacts—are microplastics and nanomaterials. Although the individual effects of these pollutants on amphibians have already been studied, significant gaps remain regarding the combined responses triggered by different classes of microplastics and nanoparticles. Given the urgency of understanding this ecotoxicological dynamic, the present study aimed to evaluate the responses of oxidative stress biomarkers, antioxidant enzymatic activity, and detoxification processes in the livers and gills of bullfrog (Aquarana catesbeiana) tadpoles exposed to polyethylene microplastics (PE-MPs) (60 mg/L) and titanium dioxide nanoparticles (TiO₂-NPs) (10 μg/L), both individually and in combination, after 15 days of exposure. Laboratory analyses demonstrated that co-exposure to microplastics and nanoparticles induced greater responses in both organs. In the gills, the mixture of these compounds resulted in increased activity of superoxide dismutase (SOD), while the groups treated individually with PE-MPs or TiO₂-NPs showed no significant changes in enzymatic levels or oxidative stress indicators. In the liver, co-exposure led to increased activity of glutathione S-transferase (GST) and elevated levels of lipid peroxidation. In the group exposed only to PE-MPs, an increase in SOD activity and lipid peroxidation levels were observed. On the other hand, neither organ exposed exclusively to TiO₂-NPs exhibited significant alterations in the analyzed parameters. These results reveal the complexity of interactions between these two contaminants and highlight the importance of studying the toxicological effects of pollutants across different organs, considering that each tissue may respond differently to various substances and that the distribution of these compounds within the organism is not uniform. Furthermore, additional studies are needed to understand the mechanisms underlying these biochemical responses, as well as further investigations into how these substances may impact other amphibian species and the ecosystems they inhabit.
Influência do cátion manganês-II como agente abiótico no metabolismo secundário de fungos extremófilos do gênero Talaromyces
(Universidade Federal de São Carlos, 2025-08-29) Alves, Mauricio Augusto Pinto Moreno da Silva; Rodrigues Filho, Edson; https://lattes.cnpq.br/3667941735597178; https://orcid.org/0000-0003-4305-0326; https://lattes.cnpq.br/0492505516508288; https://orcid.org/0009-0004-1291-7913; Pilau, Eduardo Jorge; Amaral, Jéssica Cristina; Cantanhede Filho, Antonio José; Fernandes, João Batista; https://lattes.cnpq.br/0859421816184957; https://lattes.cnpq.br/6610572791860659; https://lattes.cnpq.br/2920215807337108; https://lattes.cnpq.br/2691336077459602; https://orcid.org/0000-0002-9175-3520; https://orcid.org/0000-0002-4509-259X; https://orcid.org/0000-0002-2009-2817; https://orcid.org/0000-0002-2924-3327
This study investigated the impact of the manganese-(II) cation as an abiotic inducer in modulating the secondary metabolism of extremophilic fungi of the genus Talaromyces, with a focus on the production of bioactive compounds with antioxidant potential. Three experimental models were conducted using the species Talaromyces sp., Talaromyces fuscoviridis, and Talaromyces aureolinus, cultivated in modified media containing different concentrations of Mn²⁺, aiming to activate latent biosynthetic pathways and promote the generation of novel or poorly explored secondary metabolites. In Chapter 1, the effect of increasing manganese concentrations (0 to 1000 mM) on the metabolic profile of Talaromyces sp. was evaluated, with emphasis on significant alterations in polyketides involved in the mixed pathway of meroterpenoid biosynthesis. Seven compounds were isolated and characterized by NMR and HRMS, including phenols and hydroxybenzoic acids. Multivariate analyses (PCA and dendrogram) revealed that intermediate concentrations (125 and 250 mM) induced distinct changes in the chemical profile, suggesting disruption in the biosynthesis of specific metabolites. In Chapter 2, the extracts were subjected to antioxidant screening using an adapted DPPH-UPLC assay. The addition of Mn²⁺ enhanced the antioxidant activity of specific fractions, correlating oxidative stress with the increased production of phenolic and aromatic compounds. GC-MS analysis allowed the annotation of substances absent in the control extracts. In Chapter 3, the study focused on the fungus Talaromyces fuscoviridis, isolated from soil contaminated by copper mine tailings. The production of polyene steroids was stimulated by cultivation in rice supplemented with Mn²⁺, resulting in the isolation of two major compounds: Ergosta-3(4),7,14,22-tetraene (1a), unprecedented in the literature, and Ergosta-5,7,14,22-tetraen-3β-ol (2a), with structures confirmed by 1D/2D NMR, HRMS, and X-ray diffraction. Both exhibited antioxidant activity greater than 80% compared to β-carotene at low concentrations. PCA analysis showed clear separation between samples with and without Mn²⁺, confirming the inducing role of the cation in steroidal biosynthesis. Finally, in Chapter 4, three lactone depsidones were isolated and quantified from Talaromyces aureolinus grown in Czapek medium and rice supplemented with manganese: compound 1 (11-hydroxy-3-(1-hydroxy-3-methylbutyl)-4-methoxy-9-methyl-5H,7H-dibenzo[b,g][1,5]dioxocin-5-one), compound 2 (7-hydroxy-4,11-dimethoxy-3-vinyl-5H,7H-dibenzo[b,g][1,5]dioxocin-5-one), and compound 3 (1,6-dihydroxy-8-methyl-11H-dibenzo[b,e][1,4]dioxepin-11-one). Quantification by UPLC-MS indicated that Mn²⁺ favored the production of all three isolated compounds, suggesting a selective effect on the lactone biosynthetic pathway. The integration of spectroscopic data and molecular networking (GNPS) revealed alterations in the global chemical profile, with distinct clustering between treatments with and without Mn²⁺. The results demonstrate that manganese acts as an effective modulator of metabolic expression in extremophilic fungi, favoring the production of metabolites with biotechnological potential. This research contributes to the understanding of the adaptive response of these organisms to metal-induced stress and provides a basis for the rational exploration of microbial biodiversity as a source of novel bioactive compounds.
Estudo da resistência de genótipos de soja à herbivoria de Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)
(Universidade Federal de São Carlos, 2025-08-29) Arroyo, Victoria Patricia Pena; Forim, Moacir Rossi; https://lattes.cnpq.br/1234565160573730; Wouters, Felipe Christoff; https://lattes.cnpq.br/4392349445398645; https://lattes.cnpq.br/9409311086029770; Oliveira, Regina Vincenzi; Angolini, Fernando Figueiredo; Gusmão, Marcos Rafael; Souza, Dulce Helena Ferreira de; https://lattes.cnpq.br/6609377714413073; https://lattes.cnpq.br/8380443920606522; https://lattes.cnpq.br/4032769085084783; https://lattes.cnpq.br/3428955299526003
La soja [Glycine max (L.) Merrill] posee una elevada importancia socioeconómica, siendo Brasil su principal productor y exportador. Sin embargo, este cultivo enfrenta desafíos debido a plagas como Spodoptera frugiperda (SF), que comprometen su productividad. El control químico, aunque ampliamente utilizado, favorece la aparición de plagas resistentes y genera impactos ambientales y sobre la salud. Para mitigar estos efectos, las plantas activan mecanismos de defensa, produciendo compuestos que afectan el desarrollo y el comportamiento de los insectos. El uso de cultivares resistentes es una estrategia clave para minimizar pérdidas, dado que dichas defensas varían según el genotipo, el órgano vegetal y el tipo de herbivoría, lo que hace crucial su identificación y comprensión en la interacción insecto-planta para mejorar la caracterización de la resistencia en soja. En este contexto, el presente estudio investigó la resistencia de cuatro genotipos cultivados de soja (PI 229358, IAC 100, BRS 257, IAC PL-1) y uno silvestre (PI 407270) frente a la herbivoría de SF, considerando los efectos de la domesticación. Se realizaron ensayos biológicos, análisis nutricionales y metabólicos en hojas jóvenes, maduras y dañadas en el estadio de desarrollo V3, antes y después de la inducción por SF. El perfil metabólico fue analizado mediante UHPLC-q-TOF-MS/MS, utilizando un enfoque no dirigido. PI 229358 e IAC 100 demostraron resistencia constitutiva, mientras que BRS 257, IAC PL-1 y PI 407270 presentaron tolerancia. Las hojas jóvenes concentraron compuestos como ácidos grasos insaturados, octadecanoides y diterpenos, mientras que las hojas maduras mostraron mayor abundancia de flavonoles y triterpenos. La herbivoría activó respuestas metabólicas, especialmente en las variedades resistentes y en la soja silvestre. Se anotaron biomarcadores de resistencia a SF, como derivados de quercetina, isoflavonas, triterpenoides, una cumarina, ácidos grasos y fitoprostanos. El estudio evidencia que la domesticación no eliminó completamente la resistencia y destaca la complejidad de los mecanismos de defensa de la soja, contribuyendo al mejoramiento de cultivares y a estrategias sostenibles de control de plagas.