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Efeito do aumento de temperatura sobre a matéria orgânica dissolvida fluorescente produzida por microalgas de água doce em cultivos axênicos
(Universidade Federal de São Carlos, 2023-10-18) Cassiano-Oliveira, Israel; Bagatini, Inessa Lacativa; https://lattes.cnpq.br/3904631503604006; https://orcid.org/0000-0002-5549-2255; Sarmento, Hugo; https://lattes.cnpq.br/4515469289999439; https://orcid.org/0000-0001-5220-7992; https://lattes.cnpq.br/1891551804658283; https://orcid.org/0000-0001-8307-8388
Dissolved organic matter (DOM) encompasses a wide range of biologically derived molecules and is the most abundant and bioavailable form of carbon in aquatic environments. DOM plays a key role in the carbon cycle, as it influences pH and light penetration in the water column, affecting primary productivity, and serves as the primary energy source for heterotrophic microorganisms. Phytoplankton, through its metabolism or cellular death, represents a major source of DOM for aquatic systems. However, little is still known about the composition of these organic substrates and the factors that regulate their production and quality, especially from the perspective of global climate change. Small changes in phytoplankton-derived DOM (DOMp), triggered by changes in environmental factors, can cause shifts in microbiome structure and, therefore, carbon fluxes in aquatic food webs – thus, in the carbon cycle. To examine the consequences of temperature increase on DOMp, axenic cultures of Microcystis aeruginosa and Cyclotella sp. were subjected to +4°C warming experiments, with and without prior acclimation, and analyzed using flow cytometry, fluorescence spectroscopy, and quantification of dissolved organic carbon at different growth stages. Two proteinaceous fluorescent components and two humic/fulvic-like components were identified. While the composition of DOMp varies more pronouncedly with growth stages, temperature appears to induce changes in the bioavailability and carbon exudation rate of exudates. Values of some optical indices and spectral ratios differed from those reported for phytoplankton, which has important implications for understanding DOM in natural waters. Additionally, some fluorophores typically associated with humic compounds appear to include other substances of different nature and origin, potentially related to oxidative stress. It is expected that the results obtained in this investigation will advance the understanding of DOMp production processes, help refine the interpretation of DOM optical property data in natural environments, and contribute to a better understanding of the impact of climate change on key portions of the carbon cycle.
Agenciamentos juvenis a partir de uma pesquisa em escolas do ensino médio
(Universidade Federal de São Carlos, 2023-10-18) Amorim, Simone Cristina de; Garcia, Marcos Roberto Vieira; https://lattes.cnpq.br/3911188481669270; https://orcid.org/0000-0002-5668-2923; https://lattes.cnpq.br/0068826059223733; https://orcid.org/0000-0002-0897-6484
This thesis analyzed youth assemblages as of on research carried out in public high schools. Its conception resulted from the quadripolarity of the assemblage's conceptual scheme (strata, collective assemblages of enunciation, machinic assemblages and abstract machines) based on Deleuze-Guattarian works, and operationalized for the field with the notion of youth imbricated with the interventional research. It aimed to investigate whether young people’s capabilities on affect and be affected by at Scientific Initiation Program for High School (IC-EM) were intensified in local research, and to analyze the subthemes that presented themselves in deterritorialization or decoded. The methodology added pre-established mixed methods to the limits of its representations, thus dealing with the weekly monitoring of IC-EM, in three local schools, from September 2019 to December 2023. This period coincided with the deployment/implementation/suspension of Law 13,415, of February 16, 2017 (New Secondary Education Law), known for obstructing the critical training of young people in public secondary education. For the field results, the subtopics with intensification, deterritorialization or decoding in the trajectory of the research accompanied with youth were as follows. (1) Youth assemblages by means of the school institution: the school has shown itself to be permeated by two institutional regimes, democracy or tyranny, with episodes of oppression, but also encounters and friendship, with collective assemblage of enunciation from other places that reverberate in everyday school life and summon young people to their own modes of expression (youthful secrecy, combat against racism, respect for gender self-identification and future perspectives). (2) Young people and their families: the family bullying emerged, with criticism disguised as praise, downgrader comparisons, contradictory messages that are impossibility to comply — for young people with different inclinations and values in the family — above all the not-heterossexuals, they are shown not only as a protective institution, but as a source of repeated suffering. (3) SARS-CoV2: a viral stratum, internal to a machine assemblage where droplets or aerosols of saliva predominate, deterritorialized the routine, imposed coexistence with family members and forcerd the micromanagement of small fears. (4) Acid humor as a youth psychosocial support strategy among LGBTs+people?: emerged in one of the subgroups of students in decoding internalized meanings of mental suffering; allowing to touch difficult content in the elaboration of painful psychosocial experiences. (5) (Dis)sexuality: decoded cultural codes that confuse intensity with compulsion, harassment and violence in sexual practices; rescuing practices of freedom in machinic assemblages. (6) Indianness: young people sought ways to affirm not only indigenous descent, but a becoming-indigenous, indicative of the limit of ethnic-racial categorization, which erases assimilationist racism. School as an institution was not limited to constraining the inventive abilities of young people; before that it was a place of meetings, participation, friendship and support, where these young people could turn to those they trust. There was an intensification of the IC-EM' ability to affect and be affected in this interventional research. After all, any ability to affect and be affected depends directly on the encounters provided by the world.