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Physiological responses of chlorophyta microalgae under environmentally relevant copper concentrations: biomolecules, oxidative stress and photosynthesis
(Universidade Federal de São Carlos, 2022-02-28) Dauda, Suleiman; Lombardi, Ana Teresa; https://lattes.cnpq.br/6737850858443813; https://lattes.cnpq.br/8063471405793012
Microalgae require copper (Cu) in trace levels for their growth and metabolism. It is a vital component of certain metalloproteins, participates in the photosynthetic process, and catalyzes various redox reactions. Although this element has been widely studied concerning microalgae physiology, the effects of environmentally relevant levels have been less investigated. The aim of this study was to see the effect of environmental copper concentrations on some aspects of algae physiology, as growth rates, biomolecules (carbohydrates, lipids, proteins, and pigments) production, antioxidant response, and photosynthesis. For this, Ankistrodesmus flexuosus, Curvastrum pantanale, Monoraphidium sp., and Chlamydomonas chlorastera were the test organisms. They were kept under laboratory controlled conditions with Cu concentrations ranging from low (0.1 nM) to high (5480.0 nM) free Cu ions (Cu2+). Cultures lasted 96 h and all analyses were done in exponential growth phase. Cell densities and growth rates were unaffected in low Cu concentrations up to, 9.1 nM Cu2+ in C. chlorastera and 7.4 nM Cu2+ in the other species. In relation to pigments, β-carotene and lutein increased in C. chlorastera (1.2 mg g-1 β-carotene; 6.14 mg g-1 lutein) in 0.3–0.4 nM Cu2+. C. chlorastera had the highest, carbohydrates (> 50 pg cell-1) across all Cu concentrations tested, proteins content (270.2 pg cell-1; 0.3 nM Cu2+), and lipids (61.9% dw; 1.2 nM Cu2+). The activities of α, α-diphenyl-β-picrylhydrazyl (DPPH) radical, Glutathione S-transferase (GST), peroxidase (POD), superoxide dismutase (SOD) and malondialdehyde (MDA) content were not affected by low Cu exposure, but increased in high Cu. The microalgae effective quantum yields (ΔF⁄F_m') were more sensitive to Cu than their maximum quantum yields (F_v⁄F_m ). In Monoraphdium sp., Cu increase (3.4–7.4 nM Cu2+) increased photosynthesis, as recorded in the effective quantum yield (ΔF⁄F_m'), relative maximum electron transport rate (rETRm), saturation irradiance (Ek), and photochemical quenching (qP and qL). The non-photochemical quenching (NPQ) and PSII antenna size of Monoraphidium sp. increased in high Cu. Monoraphidium sp. also had the lowest photoinhibition (β) under high irradiance across all Cu exposures. The primary productivity of Monoraphidium sp. was unaltered in low Cu (1.7–21.4 nM Cu2+), but reduced by high Cu (589.0 nM Cu2+). Cu-elicited hormetic responses were seen in lipids content in C. chlorastera, and in photosynthesis in Monoraphidium sp. These findings show that depending on the species and concentration, Cu can stimulate biomolecules accumulation and increase photosynthesis in microalgae, without reducing growth.
Juventude negra, subjetividade, ensino médio e mercado de trabalho, um levantamento bibliográfico das publicações entre os anos 2000 e 2020
(Universidade Federal de São Carlos, 2022-02-28) Evangelista, Noely Thais; Rodrigues, Tatiane Cosentino; https://lattes.cnpq.br/8361431964064731; https://lattes.cnpq.br/6570009279752265
That research purpose to map studies on black youth, high school, and the job market. Based on the limits imposed by the context of the pandemic caused by COVID-19, this research is characterized as a bibliographic study on the subject adopted in Brazilian research with a cut between the years 2000 and 2020. The texts were selected to identify an intersection between the themes, totaling 44 theses, dissertations, and articles. The BDTD and Scielo databases were analyzed to locate and explore the writings on the subject considered changes in the country's social and formative structures. The study on education and education goes beyond the training processes in High School integrated to the perception of young blacks and blacks as possibilities in the face of their expectations about the job market. However, there is a reflection on issues that can be thought about individuals, without a school of work that considers their subjectivity and without job prospects that consider their subjectivity and without work prospects after the day of reproduction going and without work prospects future of denial and naturalization of this context of inequalities.
Esgoto doméstico tratado como fonte de água e nutrientes no cultivo em substrato do morangueiro
(Universidade Federal de São Carlos, 2022-02-28) Lopes, Mariano Vieira dos Santos de Souza; Cardoso, Jean Carlos; https://lattes.cnpq.br/3681181863704059; Souza, Claudinei Fonseca; https://lattes.cnpq.br/4858219292242433; https://lattes.cnpq.br/7759179876918493
The disproportionate distribution of natural resources and the demand for water and nutrients in agricultural systems make it important to search for alternative sources for irrigation. Thus, a mitigating measure that has been disseminated is the use of treated domestic sewage in agriculture, in addition to providing water for agricultural crops, can ensure increased production due to the contribution of nutrients and organic matter. Thus, the objective of this work was to evaluate the feasibility of the cultivation technique, productivity and quality of strawberries (Fragaria x ananassa Duch) San Andréas obtained in cultivation with substrate, using solution from treated domestic sewage with and without the addition of mineral fertilizers. The experiment was conducted in an agricultural greenhouse, in which strawberry plants were grown in a system with Styrofoam troughs filled with coconut fiber substrate. The three types of treatments: (TA) drinking water plus mineral fertilizers, (TRA) treated domestic sewage supplemented with mineral fertilizers, and (TR) treated domestic sewage only were experimentally designed in randomized block design. Quantitative results were evaluated using analysis of variance and followed by the Shapiro-Wilk test and Tukey's test at 5% significance level. The experimental results showed that the use of treated domestic sewage as the only source of water and nutrients (TR), resulted in plants with low productivity and commercial fruit quality. The productivity and quality of the fruits such as number of fruits, length, diameter, fresh mass and total soluble solids, produced with the TRA solution was statistically similar to the conventional growing system (TA), demonstrating the phytotechnical feasibility of using treated sewage water. The substrate culture technique also proved to be safe, with no reported contamination of the fruits by Escherichia coli bacteria. The use of treated domestic wastewater promoted savings of 13.1% mineral fertilizers and approximately 4500 L of drinking water during the entire cultivation cycle. With these results, it is concluded that the use of treated household wastewater as a source of water and nutrients in substrate cultivation presents feasibility in productivity and fruit quality of strawberry without compromising food safety.
Repensando o negro no debate da formação social brasileira: a contribuição de Joel Rufino dos Santos
(Universidade Federal de São Carlos, 2022-02-28) Martins, Jonas Lara; Cepêda, Vera Alves; https://lattes.cnpq.br/4917331423373631; https://lattes.cnpq.br/6901130329855417
The work of Joel Rufino dos Santos contains an important reflection on the contemporary world, emphasizing a new version of Brazilian history in the midst of the consolidation of industrial society in Brazil, a moment when intellectuals debated the theme of the national project and acted in full process of implementation and routinization of the social sciences in Brazil, privileging different themes and problems along this trajectory. The schedule of issues analyzed by Rufino is anchored in the trajectory of racial exclusion long rooted in the Brazilian tradition, under multiple aspects. Although Joel Rufino do Santos' work is extensive and deals with a complex thematic schedule, this work intends to analyze the author's intellectual thinking on two points: the first, closer in nature to the debate on social thought and interpretations about Brazil, will focus on a critique and review of the history of Brazilian education and the role of black people in it; the second will deal with the trajectory of Joel Rufino dos Santos. In the end, it is intended to give visibility to the thought of this black intellectual in whose agenda of reflection important themes are found for the understanding of how the racial question, the theme of subjectivity, and the sociopolitical dimension of blacks are articulated with national formation (yesterday and today).