RESUMO

Phosphorus is a limiting element for the productivity of mangroves, which in turn are important ecosystems in regulating nutrients cycle and climate change by sequestering carbon (C). Despite this, there is an intense process of degradation in these environments. In addition to providing socio-environmental services, mangrove replanting can also alter the dynamics of nutrients in soils. Therefore, this study aims to understand the changes in soil phosphorus (P) fractions after a mangrove restoration. Soil samples from an unvegetated area (NV), a mature mangrove (R) and 7 and 9 year old replanted mangroves at SE-Brazil (APA Guapi-mirim, Rio de Janeiro state) were collected and analyzed to characterize the redox conditions (Eh), pH, and iron (Fe) fractionation, Total Organic Carbon (TOC) contents and P fractionation (exchangeable P; P associated with reducible Fe and Mn oxyhydroxides; associated with Al silicates and hydroxides; associated with humic acids; associated with Ca and Mg; associated with humin). The results indicate an increase in TOC as the age of the mangrove restoration increases (from 8.6 to 17.9%). The pH values were significantly lower, reaching very acidic values, associated with an increase in Eh. Both parameters also showed strong seasonal variation, with a drop in Eh during the wet period (from 165% to -46%) and an increase in pH in the same period (from 6.0 to 6.7). Regarding P fractionation, the main P pool was organic P forms, which showed the highest concentrations in all studied sites. Unvegetated areas showed higher organic P forms (NV: 108.8 µg g-1) than vegetated areas (M7: 55.7 µg g-1, M9: 83.6 µg g-1, R: 87.3 µg g-1). Vegetated sites also showed lower levels of the PEx, PFeMn and Papatite fractions (total forest mean: 2.4 µg g-1, 5.8 µg g-1, 3.0 µg g-1, respectively). Besides no clear trend on P fractionation through seasons and forest age, pseudo-total P increased following the forest recovery (e.g. M7

Assuntos

Fósforo , Solo , Áreas Alagadas , Fósforo/análise , Solo/química , Carbono , Ecossistema

RESUMO

Population growth has driven an increased demand for solid construction materials, leading to higher amounts of construction and demolition waste (C&DW). Efficient strategies to manage this waste include reduction, reuse, and recycling. Technosols-soils engineered from recycled waste-can potentially help with environmental challenges. However, there is a critical need to explore the potential of Technosols constructed with C&DW for land reclamation, through the growth of native vegetation. The objective of this study was to investigate this potential by studying two Brazilian native tree species (Guazuma ulmifolia and Piptadenia gonoacantha). Technosols were created using C&DW, with and without organic compost and a liquid biofertilizer. A soil health index (SHI) was applied to evaluate the soil quality regarding physical, chemical, and biological indicators of Technosols compared to a control soil (Ferralsol). The results showed that P. gonoacantha plants presented the same height and total biomass in all treatments, while G. ulmifolia plants exhibited greater height and total biomass when grown in Technosols. The enhanced plant development in the Technosols was primarily associated with higher cation exchangeable capacity and nutrients concentration in plant tissues. Technosols with added compost provided higher fertility and total organic carbon. Additionally, Technosols presented higher SHI (∼0.68) compared to control (∼0.38) for both studied species. Our experiment reveals that construction and demolition waste (C&DW) have significant potential to form healthy Technosols capable of supporting the growth of native Brazilian trees. This approach offers a promising alternative for addressing C&DW disposal challenges while serving as a nature-based solution for land reclamation.

Assuntos

Materiais de Construção , Reciclagem , Solo , Solo/química , Reciclagem/métodos , Brasil , Compostagem/métodos , Biomassa , Gerenciamento de Resíduos/métodos , Árvores , Resíduos Industriais

RESUMO

Syphilis remains a significant public health concern, with serological assays being the primary method for diagnosis. However, molecular techniques have proven to be reliable tools for the diagnosis and understanding of the transmission dynamics of Treponema pallidum infection. This study aimed to evaluate the efficacy of syphilis treatment using molecular assays, perform Enhanced Centers for Disease Control and Prevention (ECDC) typing, and analyze resistance (macrolide and doxycycline) in the T. pallidum isolate. PCR assay amplified treponemal DNA only from the lesion sample, whereas qPCR was able to amplify DNA in both lesion and blood samples before treatment. Throughout the treatment follow-up, qPCR effectively did not identify treponemal DNA in the blood for up to one to two weeks after treatment. ECDC typing revealed the genotype 14 e/g in the Brazilian T. pallidum isolate, and the presence of the A2058G mutation in 23 S rRNA gene, indicating macrolide resistance. Although, the G1058C mutation in 16 S rRNA gene was not detected. Notably, qPCR demonstrated its potential for diagnosing T. pallidum in blood samples, even when the treponemal DNA levels were low, enabling more accurate and sensitive diagnosis and guiding better syphilis therapy. In addition, to the best of our knowledge, this study represents the first identification of subtype 14 e/g and azithromycin resistance in a Brazilian T. pallidum isolate.

Assuntos

Antibacterianos , Sífilis , Treponema pallidum , Treponema pallidum/genética , Treponema pallidum/isolamento & purificação , Treponema pallidum/classificação , Treponema pallidum/efeitos dos fármacos , Sífilis/microbiologia , Sífilis/diagnóstico , Sífilis/tratamento farmacológico , Humanos , Brasil , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Genótipo , Farmacorresistência Bacteriana/genética , DNA Bacteriano/genética , Masculino , Macrolídeos/farmacologia , Tipagem Molecular/métodos , Doxiciclina/uso terapêutico , Adulto , RNA Ribossômico 23S/genética , Seguimentos

RESUMO

A mining tailing dam rupture in Brazil in November 2015 released millions of tons of mining waste into the Rio Doce ecosystem, leading to long-term aquatic ecosystem impacts. Although multiple lines of evidence indicate tailings associations with potentially toxic elements in estuarine sediments and biological impact and bioaccumulation pathways in fishes, the extent of contamination in base benthic species is still largely unknown. Moreover, Rare Earth Elements (REE) have not received any attention in this regard. This study assessed REE in fiddler crabs (Minuca rapax) sampled from the Rio Doce estuary in 2017, nearly 2 years after the disaster. The ΣREE in crab hepatopancreas and muscle were high (327.83 mg kg-1 w.w. and 33.84 mg kg-1 w.w., respectively, compared to other assessments in crabs, indicating a preference for REE bioaccumulation in the hepatopancreas compared to muscle. Neodimium, La, and Ce were detected at the highest concentrations. The REE from the Rio Doce Basin were, thus, transported and deposited in the estuary with the mine tailings slurry, leading to bioaccumulation in crabs. This may lead to trophic effects and other ecological impacts not readily measured by typical impact assessment studies, revealing an invisible and not typically acknowledged damage to the Rio Doce estuary.

RESUMO

Indigenous communities in Brazil have a complex epidemiological profile, which increases their chances of contracting sexually transmitted diseases. However, limited data is available on Treponema pallidum infections in this population. We investigated the seroprevalence and risk factors associated with T. pallidum infection in an indigenous population of Dourados, Mato Grosso do Sul. Blood samples were collected from September 2017 to March 2020, and the participants were interviewed to obtain comprehensive data on demography and sexual behavior. Serological tests were performed to detect T. pallidum infection. Besides conducting descriptive analysis, we performed Chi-squared tests and determined the bivariate odds ratio. The data were also analyzed using logistic regression. Among the 2190 invited individuals, 1927 (88%) were included in this study. The seroprevalence of T. pallidum infection was 2.91%. The results of a multivariate analysis showed that individuals who were 30-39 years old, with up to 4 years of school education, living in households without piped water, with a history of genital lesions, multiple sexual partners, and having a history of STIs had the highest seroprevalence of T. pallidum. This study showed that behavioral, social, and economic factors play an important role in the transmission of T. pallidum within the indigenous population. Thus, targeted intervention, including imparting education in the native language, mass testing initiatives, and implementing public policies to improve socioeconomic indicators, is needed to reduce the cases of syphilis in this community.

Assuntos

Sífilis , Treponema pallidum , Humanos , Brasil/epidemiologia , Masculino , Adulto , Feminino , Sífilis/epidemiologia , Sífilis/sangue , Estudos Soroepidemiológicos , Estudos Transversais , Treponema pallidum/imunologia , Adulto Jovem , Pessoa de Meia-Idade , Adolescente , Fatores de Risco , Povos Indígenas , Comportamento Sexual

RESUMO

Mangroves forests may be important sinks of carbon in coastal areas but upon their death, these forests may become net sources of carbon dioxide (CO2) and methane (CH4) to the atmosphere. Here we assessed the spatial and temporal variability in soil CO2 and CH4 fluxes from dead mangrove forests and paired intact sites in SE-Brazil. Our findings demonstrated that during warmer and drier conditions, CO2 soil flux was 183 % higher in live mangrove forests when compared to the dead mangrove forests. Soil CH4 emissions in live forests were > 1.4-fold higher than the global mangrove average. During the wet season, soil GHG emissions dropped significantly at all sites. During warmer conditions, mangroves were net sources of GHG, with a potential warming effect (GWP100) of 32.9 ± 10.2 (±SE) Mg CO2e ha-1 y-1. Overall, we found that dead mangroves did not release great amounts of GHG after three years of forest loss.

Assuntos

Dióxido de Carbono , Monitoramento Ambiental , Gases de Efeito Estufa , Metano , Solo , Áreas Alagadas , Brasil , Gases de Efeito Estufa/análise , Solo/química , Dióxido de Carbono/análise , Metano/análise , Florestas

RESUMO

Coastal wetlands are known for their diverse ecosystems, yet their soil characteristics are often misunderstood and thought to be monotonous. These soils are frequently subjected to saline water saturation, leading to unique soil processes. However, the combination and intensity of these processes can vary considerably across different ecosystems. In this study, we hypothesize that these diverse soil processes not only govern the geochemical conditions in coastal ecosystems but also influence their ability to deliver ecosystem services. To test this hypothesis, we conducted soil analyses in mangroves, seagrass meadows, and hypersaline tidal flats along the Brazilian coast. We used key soil properties as indicators of soil processes and developed a conceptual model linking soil processes and soil-related ecosystem services in these environments. Under more anoxic conditions, the intense soil organic matter accumulation and sulfidization processes in mangroves evidence their significance in terms of climate regulation through organic carbon sequestration and contaminants immobilization. Similarly, pronounced sulfidization in seagrasses underscores their ability to immobilize contaminants. In contrast, hypersaline tidal flats soils exhibit increased intensities of salinization and calcification processes, leading to a high capacity for accumulating inorganic carbon as secondary carbonates (CaCO3), underscoring their role in climate regulation through inorganic carbon sequestration. Our findings show that contrary to previously thought coastal wetlands are far from monotonous, exhibiting significant variations in the types and intensities of soil processes, which in turn influence their capacity to deliver ecosystem services. This understanding is pivotal for guiding effective management strategies to enhance ecosystem services in coastal wetlands.

Assuntos

Solo , Áreas Alagadas , Solo/química , Brasil , Ecossistema , Salinidade

RESUMO

Syphilis remains a public health concern in Brazil, and the data on the characterization and resistance of Treponema pallidum in Brazil is limited. The present study aimed to detect Treponema DNA in the lesions and blood samples obtained from individuals diagnosed with syphilis. The Brazilian isolates were submitted to the Enhanced Centers for Disease Control and Prevention (ECDC) scheme and also analyzed for resistance gene. Treponemal DNA from 18 lesions and 18 blood specimens were submitted for amplification using Polymerase Chain Reaction (PCR) and Polymerase Chain Reaction in Real Time (RT-PCR). Eight samples from lesions and eight from blood were positive in the RT-PCR analysis. Eight lesions and three blood samples were positive using PCR. Two samples exhibited azithromycin resistance. The Brazilian isolate types 14d/g, 14 d/c, 15d/c, and 15d/e were identified using the ECDC scheme. The three subtypes 14d/c, 15d/c, and 15d/e have been identified in Brazil for the first time.

Assuntos

DNA Bacteriano , Sífilis , Treponema pallidum , Humanos , Treponema pallidum/genética , Treponema pallidum/isolamento & purificação , Treponema pallidum/classificação , Brasil , Sífilis/microbiologia , Sífilis/diagnóstico , DNA Bacteriano/genética , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Masculino , Genótipo , Feminino , Adulto , Reação em Cadeia da Polimerase , Pessoa de Meia-Idade , Azitromicina/farmacologia , Reação em Cadeia da Polimerase em Tempo Real

RESUMO

This study investigates the impact of seasonality on estuarine soil geochemistry, focusing on redox-sensitive elements, particularly Fe, in a tropical estuary affected by Fe-rich mine tailings. We analyzed soil samples for variations in particle size, pH, redox potential (Eh), and the content of Fe, Mn, Cr, Cu, Ni, and Pb. Additionally, sequential extraction was employed to understand the fate of these elements. Results revealed dynamic changes in the soil geochemical environment, transitioning between near-neutral and suboxic/anoxic conditions in the wet season and slightly acidic to suboxic/oxic conditions in the dry season. During the wet season, fine particle deposition (83%) rich in Fe (50 g kg-1), primarily comprising crystalline Fe oxides, occurred significantly. Conversely, short-range ordered Fe oxides dominated during the dry season. Over consecutive wet/dry seasons, substantial losses of Fe (-55%), Mn (-41%), and other potentially toxic elements (Cr: -44%, Cu: -31%, Ni: -25%, Pb: -9%) were observed. Despite lower pseudo-total PTE contents, exchangeable PTEs associated with carbonate content increased over time (Cu: +188%, Ni: +557%, Pb: +99%). Modeling indicated climatic variables and short-range oxides substantially influenced PTE bioavailability, emphasizing the ephemeral Fe oxide control during the wet season and heightened ecological and health risks during the dry seasons.

Assuntos

Estuários , Mineração , Estações do Ano , Monitoramento Ambiental , Poluentes do Solo/análise , Metais Pesados/análise , Poluentes Químicos da Água/análise , Clima Tropical , Ferro/análise , Concentração de Íons de Hidrogênio , Oxirredução

RESUMO

INTRODUCTION: Although the adaptive immune responses to the CoronaVac vaccine are known, their dynamics in indigenous communities remain unclear. In this study, we assessed the humoral and cellular immune responses to CoronaVac (Sinovac Biotech Life Sciences, 2021 NCT05225285, Beijing, China), in immunized Brazilian indigenous individuals. METHODS: We conducted a prospective cohort study on indigenous Brazilian people between February 2021 and June 2021. Analyses of immune responses were carried out before (T1) and after a vaccination schedule was completed (T2). Demographic data were collected using a questionnaire. RESULTS: We initially included 328 patients; among them, 120 (36.6%) had no SARS-CoV-2 antibodies. Peripheral blood mononuclear cells (PBMCs) were collected from 106 patients during follow-up visits, of which 91 samples were analyzed by immunophenotyping assay to detect SARS-CoV-2-specific memory T-cell response. Post-vaccination, the levels of memory B-cells and Natural Killer T-lymphocytes increased. Bororó village residents, females, and Terena ethnic group members had higher levels of anti-spike IgG antibodies post-vaccination, whereas alcohol and tobacco users had lower concentrations. CONCLUSIONS: To our best knowledge, this was the first comprehensive assessment of antibody and T-cell responses against CoronaVac vaccination in indigenous patients. Our findings showed that antibody response and T-cell immunity against SARS-CoV-2 were present in most patients following the vaccination schedule.