Federal Institute of São Paulo

The escalating presence of microplastics (MPs) in aquatic ecosystems has sparked significant concern due to their detrimental effects on biota. A current debate revolves around the potential influence of type, size, and co-exposure with other contaminants on the toxicity of MPs. Here, two 21-day experiments with adult Danio rerio were carried out to verify the effects of different particle sizes of polyethylene terephthalate (PET-MPs) (300–425 μm and 53–75 μm), at two different environmentally relevant concentrations: 983 particles. L− 1 and 330 particles. L− 1, and to demonstrate the possible effects of Cd (10 µg. L− 1), 53 μm PET-MP (330 particles. L− 1) and their mixture (PET-MP + Cd), on a set of biochemical indicators: total proteins, carbonylated protein (CP), glucose, triglycerides, lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) activity. During exposure, there was no mortality. For the largest size (300–425 μm) there was a significant increase in CP levels, and a decrease in glucose and LDH levels compared to the control in both concentrations. In the experiment with PET-MPs co-exposed to Cd, the CP levels showed a significant increase in the PET-MP + Cd group compared to the control and PET-MP alone, evidence of oxidative stress due to the addition of Cd. LDH levels decreased significantly when Cd was added to the PET-MP. MDH of the Cd group showed a significant increase when compared to the control group and PET-MP alone. Our study demonstrated that the toxicity of PET-MPs varied depending on the size, concentration, and combination with Cd.

Plasma electrolytic oxidation (PEO) is a derivative method of conventional anodization. In this process, the anodic oxide layer formed on the anode is subjected to a high electrical field. This leads to dielectric breakdown and ignites plasma micro-arcs across the anodized surface, thereby altering the formation of the oxide layer. This work presents the results of an investigation into the influence of the electrolyte composition on the electrochemical response of Nb2O5 films produced under the PEO regime, as well as the coating’s photocatalytic properties against dye degradation under UV light. Niobium substrates were anodized in an acid medium (C2H2O4 and H3PO4) and an alkaline medium (KOH) using a DC power source in galvanostatic mode and electrolyte temperature control. The samples were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectroscopy (DRS). During the PEO synthesis process using different types of electrolytes, distinct behaviors were observed in the temperature and voltage (V) vs. time (s) curves, indicating variations in surface composition. The photoactivity of the samples was investigated through photodegradation tests of aqueous solutions of Methylene Blue (MB) and Rhodamine B (RhB) under UV light. The results showed that the sample anodized with an electrolyte containing 0.1 mol L−1 of C2H2O4 exhibited higher photoactivity mainly due to the surface of the film having a larger portion of Nb2O5 compared to the other samples. Sample Nb_C2H2O4 also exhibits the lowest charge transfer resistance, indicating a more efficient interface for charge transfer.

Air pollution, especially in urban areas, is the result of a complex mixture of natural and anthropogenic emissions and their atmospheric processing. It causes millions of premature deaths worldwide and affects plant metabolism, which in turn alters the emissions of Biogenic Volatile Organic Compound (BVOCs) by plants. By taking the subtropical Metropolitan Area of São Paulo (MASP) as a natural laboratory, the BIOMASP+ project (BIOsphere-atmosphere interactions in the Metropolitan Area of São Paulo - plus ) aims to evaluate the interplay between the biosphere and secondary pollution (ozone and SOA formation and aging). The Brazilian Atlantic Forest (Mata Atlântica) is the target ecosystem as the fifth biodiversity hotspot in the world. Here we present the scientific motivations of the project, its methodology and the preliminary observations from the Special Observation Periods of year 2023 (SOP1, 2, 3 and 4). BIOMASP+ is (i) integrative, by combining in-situ/remote/laboratory observations and modeling, (ii) multidisciplinary, addressing micrometeorology, urban climate, atmospheric chemistry and biology. The project involves multiple nested scales: from leaf to above-canopy levels, from very short time (microseconds) to multi-year scale, from few millimeters (turbulence scale) to synoptic scale. In particular, the experimental effort relies on the implementation of two contrasting supersites (primary forest and urban forest) with a 30-m and 20-m flux towers, respectively, and a variety of state-of-the-art instruments. Ambient observations and the quantification of BVOC emissions have highlighted the complex interactions between meteorology, atmospheric composition of pollution, biogenic emissions of representative remnants of the Atlantic Forest and anthropogenic emissions.

Understanding the biogeographic patterns that explain species distribution in the Americas is a long and challenging endeavor. Insects represent a potentially promising group for these kinds of investigations, but deficits in basic taxonomic and systematic knowledge hinder the development of many studies. In this context, a cladistic analysis of the Pan-American genus Achradocera Becker (Diptera: Dolichopodidae: Diaphorinae) was conducted using a morphology-based matrix comprising 54 characters and 18 terminal taxa, including all 12 known species of the genus and six outgroup taxa. The analysis yielded two topologies under equal weighting and one under implied weighting of characters. Achradocera was recovered as monophyletic, and two species groups are proposed: the barbata group (Nearctic: A. barbata and A. arcuata) and the femoralis group (Neotropical: A. excavata, A. femoralis, A. meridionalis, and A. tuberculata). Biogeographic analyses were performed using the Geographically Explicit Event Model (GEM) method, which identified vicariance as the primary driver of speciation events in Achradocera, with founder events playing a secondary role. The results provide insights into the patterns that may explain the evolutionary history of the genus across the Americas, and potentially contributing to the understanding of patterns observed in other taxa with similar distributions, while also fostering discussions that can be integrated into broader frameworks, such as insect biogeography and studies of other taxa.

Microbial biological control agents are a sustainable alternative to synthetic pesticides, yet their widespread application is limited by a lack of environmental resilience of commercial products. To address this, we exploited honey—a stringent ecological niche—as a reservoir for stress-tolerant bacteria. In this study, the bioprospection utilizing five types of commercially available honeys yielded a collection of 53 bacteria and 10 fungi. All bacterial isolates were evaluated for antimicrobial activity against a laboratory-standard bacterium and yeast, and six economically relevant phytopathogenic microorganisms. Initial screening with standard laboratory organisms proved to be an efficient method to detect strains with antimicrobial potential, correlating significantly with further phytopathogen inhibition (Spearman’s r = 0.4512, p = 0.0005). Two promising strains, M2.7 and M3.18, were selected for quantitative dual-culture assays along with molecular identification using 16S rDNA and gyrA gene sequencing, classifying them as Bacillus velezensis. These strains exhibited high inhibitory effects against the pathogens (p > 0.001), often with equivalent efficacy to the commercial biocontrol strain, and also induced significant phytopathogen hyphal deformities, such as increased septation and swelling. These findings support honey as a viable source of robust biocontrol agents, offering a sustainable strategy to substitute or complement current agrochemicals.