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Proteomic analysis of cryopreserved Prochilodus lineatus seminal plasma: effects of melatonin on sperm quality preservation
(Universidade Federal de Lavras, 2025-11-10) Lopes, Guilherme Antonio de Gouvêa; Murgas, Luis David Solis; Motta, Naiara Cristina; Madureira, Ana Paula; Carneiro, William Franco
This study evaluated the effects of melatonin supplementation on sperm cryopreservation and seminal plasma proteomics in the neotropical fish Prochilodus lineatus. Sperm Cryopreservation is a key technique for aquaculture and species conservation but often causes oxidative stress, structural damage, and metabolic impairment in sperm cells. In this study, sperm samples (n = 9 per group) were cryopreserved with or without 2 mM melatonin, followed by post-thaw analyses of motility, vigor, membrane integrity, morphology, and proteomic profile. Melatonin significantly improved sperm quality after thawing, increasing motility from 43.15 ± 16.95% to 65.72 ± 16.32% (p = 0.042), as well as straight-line velocity (VSL; 10.53 ± 4.19 to 16.57 ± 5.64 μm/s; p = 0.033) and average path velocity (VAP; 15.73 ± 5.48 to 22.90 ± 6.75 μm/s; p = 0.046), while curvilinear velocity (VCL; p = 0.075) and beat-cross frequency (BCF; p = 0.061) showed positive but non-significant trends. Morphological evaluation revealed a reduction in strongly coiled tails, whereas membrane integrity (42–84%) and total abnormality rates (49–51%) were unaffected. Proteomic analysis identified 1,238 proteins, including eight exclusively expressed under melatonin treatment, mainly associated with energy metabolism, antioxidant defense, and proteostasis. Melatonin upregulated enzymes related to ATP production, redox balance, and protein degradation, while downregulating proteins linked to cryo-induced damage. These findings demonstrate that melatonin exerts a multifaceted protective effect during sperm cryopreservation by preserving energy metabolism, reinforcing antioxidant capacity, maintaining structural and genomic integrity, and improving post-thaw motility. Overall, this study provides the most comprehensive proteomic dataset of P. lineatus seminal plasma to date and highlights melatonin as a promising additive for enhancing sperm cryopreservation protocols in aquaculture and conservation.
Desempenho biológico e reprodutivo de Tetrastichus howardi (Hymenoptera: Eulophidae) criado em hospedeiro alternativo
(Universidade Federal de Lavras, 2026-01-22) Souza, Maria Isabel Almeida; Marucci, Rosangela Cristina; Peñaflor, Maria Fernanda Gomes Villalba; Souza, Ivana Lemos
The mass rearing of natural enemies is a strategy that optimizes the use of biological control in agriculture. Tetrastichus howardi (Olliff, 1893) (Hymenoptera: Eulophidae) is a gregarious endoparasitoid that has stood out in the control of lepidopteran pests and can be reared on an alternative host, Tenebrio molitor L. (1758) (Coleoptera: Tenebrionidae). However, successive rearing on the same host may affect the reproductive characteristics of the insect and lead to population degeneration. In addition, reproductive strategies such as superparasitism, host exposure time, and energetic supplementation may ensure greater reproductive success. The objective of this research was to evaluate biological and reproductive parameters of T. howardi reared on T. molitor over successive generations. Five bioassays were conducted: (i) evaluation of the biological and reproductive characteristics of T. howardi on T. molitor across generations; (ii) different exposure times of the parasitoid to the host; (iii) reproductive capacity of T. howardi at low densities; (iv) evaluation of superparasitism strategies; and (v) supplementation of parasitoid females with a honey and water solution. The following parameters were evaluated: parasitism and emergence rates, total progeny number, number of females and males, sex ratio, life cycle, and longevity. For insect counting, a stereomicroscope was used, and sex determination was performed based on antennal morphology. All experiments were analyzed using the R software (R Core Team, 2024), version 4.4.1. Generalized Linear Models (GLM) were applied, with a quasi-Poisson distribution used for count data, a binomial distribution for parasitism and emergence rates, and beta regression for sex ratio, all considering a 5% significance level. The results demonstrated that T. howardi parasitized and emerged in all evaluated generations; however, a reduction in the number of females was observed from the ninth generation onward. Between the fifth and sixth generations, biological and reproductive characteristics showed stabilization. An exposure time of 72 hours of the parasitoid to the host resulted in higher parasitism and emergence rates, as well as a greater number of offspring. No significant differences were observed among the tested parasitoid-to-pupa densities; however, pupal abnormalities were recorded under low parasitoid density conditions. Superparasitism increased parasitism and emergence rates compared with self-superparasitism and reduced the life cycle and longevity. Energetic supplementation increased parasitism and emergence rates and enhanced female longevity. It is concluded that T. howardi can be reared on T. molitor pupae without changes in reproductive characteristics for up to eight generations, that the ideal exposure time for better utilization of host resources and higher offspring production is 72 hours, that low densities should be avoided, that superparasitism strategies are important for the reproduction of this species, and that energetic supplementation of females is essential.
Práticas literárias na educação infantil: um olhar a partir dos princípios de Reggio Emilia
(Universidade Federal de Lavras, 2025-12-19) Oliveira, Andressa Maria Ferreira de Souza; Goulart, Ilsa do Carmo Vieira; Alvarenga, Carolina Fari; Carvalho, Eliane Vianey
This study aimed to analyze literary reading practices developed by Early Childhood Education teachers in light of the principles of the Reggio Emilia approach, seeking to understand to what extent such practices relate to its pedagogical foundations. The specific objectives were: to contextualize the Reggio Emilia pedagogical approach; to identify the principles that guide educational work related to literary reading; and to investigate how these practices are implemented in the institution studied. This is a field study with a qualitative, descriptive approach, conducted in a municipal public school that serves Early Childhood Education (preschool) and Elementary Education (Grades I and II), with the participation of three preschool teachers. Data were produced through narrative interviews with the teachers. The theoretical framework was grounded in studies on reading and literary reading (Martins, 2006; Paulino, 2006; Cosson, 2006; Bajour, 2012; Chambers, 2011) and in the principles of the Reggio Emilia approach (Malaguzzi, 1999; Rinaldi, 1999; Gandini, 1999; Edwards, 2011). Data analysis was organized into three thematic axes: (1) literary reading practices in preschool; (2) children’s protagonism and the organization of the learning environment; and (3) the Reggio Emilia approach and its relationship with pedagogical practice. The results indicate that the teachers promote reading activities that value pleasure, imagination, and children’s expression, using reading circles, puppets, and dramatizations. It was observed that the teachers respect children’s rhythms and interests and seek to design pedagogical proposals based on their curiosities.Despite the positive intentions and the care devoted to reading practices, no consistent alignment with the principles of the Reggio Emilia approach was observed. Children’s protagonism, the organization of the environment, and teacher mediation appear sporadically, but do not reflect the core conceptions of the approach. As an educational product, a continuing education course entitled “Reading as a Language in Early Childhood Education: A Reggio Emilia–Inspired Perspective” was developed for the participating Early Childhood Education teachers, with the possibility of expansion to other educators. The course aims to provide theoretical and practical support to foster critical reflection on pedagogical practice and to open pathways for a future alignment with the foundations of the Reggio Emilia approach.
Geração Z e Cold Brew: análise das preferências e tendências de consumo
(Universidade Federal de Lavras, 2025-07-12) Sousa, Larissa Nunes de; Carneiro, João de Deus Sousa; Rodrigues, Jéssica Ferreira; Schmidt, Mariana Camargo; Fontan, Gabrielle Cardoso Reis
The coffee market in Brazil, the world's second-largest consumer, is undergoing a transformation driven by new consumption habits, especially among Generation Z. This demographic exhibits lower consumption of traditional coffee than other generations, creating a market gap and, simultaneously, an opportunity for innovative products. In this context, cold brew, a cold coffee-based beverage, emerges as a promising alternative. The objective of this work was to develop ready-to-drink (RTD) cold brew concepts, made with specialty coffees and targeted at Generation Z consumers. The research was conducted in three stages: (1) an analysis of the Brazilian cold brew market; (2) a qualitative investigation with focus groups to assess the opinions, preferences, knowledge, and reasons for consumption and non-consumption of cold coffee-based beverages (cold brew) by Generation Z; and (3) data consolidation for the creation of the concepts. The market analysis revealed a niche segment dominated by artisanal brands. The focus groups revealed that the positive perception of cold brew is centered on its smoothness and natural sweetness. The research identified that adding value to the product depends on attributes such as packaging choice (with an emphasis on glass) and the communication of health and sustainability. The analysis of this data allowed for the identification of two distinct consumer profiles, which served as the basis for proposing two ready-to-drink cold brew concepts: "RAÍZES," focused on the purity and origin of specialty coffee, and "BRISA," a refreshing beverage with added natural flavors. It is concluded that the success of cold brew for this audience is conditioned on a strategy that transcends flavor, encompassing values of health and sustainability, and that the creation of targeted concepts, as proposed, demonstrates a viable path for the industry to connect with Generation Z.