Aqueous Two Phase Systems (ATPS) composed of 2-propanol + inorganic salt (Na2SO4/MgSO4) + water, at different temperatures T = (20, 30, 40 and 50) °C were applied in the partition studies of the textile dyes Yellow, Blue Royal and Red Dianix CC. The thermodynamic parameters of the free transfer energy (∆Gtr), enthalpy (∆Htr) and entropy (∆Str), respectively, were determined for dye partitioning, using the Van’t Hoff equation. The values of the partition coefficients of textile dyes Yellow, Royal Blue and Red Dianix CC, ranged from 14.21 to 1610.00, 15.15 to 994.00 and 17.32 to 311.75, respectively; and with dye extraction yields ranging from 93.17 to 99.93; 94.53 to 99.89 and 97.19 to 99.64, respectively. Based on the ∆Gtr results, it was verified that the dyes partition process was thermodynamically spontaneous, in all evaluated systems. For the 2-propanol + sodium sulfate ATPS, there was a prevalence of the enthalpic contribution over the entropic contribution (∆Htr > ∆Str), while for the 2-propanol + magnesium sulfate systems, a greater predominance of the entropic contribution was observed (∆Htr < ∆Str). The recovery yields (Y) values obtained were above 90% for all systems.

Resumo Em todas as escalas, a relação turismo-pandemia suscita diferentes análises frente à complexidade tanto da atividade turística, que tem no espaço seu principal recurso, quanto da propagação da Covid-19, que ensejou mudanças no comportamento humano. Tendo em vista que a região Nordeste do Brasil se configurou ao longo dos anos como um importante polo receptor de turistas, o artigo analisa o impacto da pandemia na atividade turística da região e discute a influência do turismo na disseminação do vírus no território a partir dos fluxos e da circulação massiva de turistas. Metodologicamente, utilizou-se da pesquisa de base quanti-qualitativa e do tipo exploratória, adotando como procedimentos a revisão bibliográfica, a pesquisa documental e o levantamento de dados, a fim de subsidiar a análise pretendida. Ao fim, apontam-se desafios e tendências da atividade turística na região, considerando sua dinâmica a partir das ações dos principais agentes públicos e privados.

Abstract The tourism-pandemic relationship raises different analyses at all scales given the complexity of the tourist activity, which has its main resource in space, and the spread of Covid-19 which has led to changes in human behavior. Considering that the northeastern region of Brazil has been configured, over the years, as an important reception hub of tourists, the article aims to analyze the impact of the pandemic on the tourist activity of that region. It also discusses the influence of tourism on the spread of the virus in the territory from the flows and massive circulation of tourists. Methodologically, the quantitative-qualitative and exploratory research were used with bibliographic survey, documentary research, and data collection as procedures to support the intended analysis. Finally, the challenges and trends of tourism activity in the region are pointed out, considering the dynamics from the actions of the main public and private agents.

Resumen En todas las escalas, la relación turismo-pandemia plantea análisis ante a la complejidad tanto de la actividad turística, que tiene en el espacio su principal recurso, como de la diseminación de la Covid-19 que ha cambiado el comportamiento humano. Considerando que la región Nordeste de Brasil se ha convertido, a lo largo de los años, como importante polo turístico, la ponencia objetiva analizar el impacto de la pandemia en la actividad turística de esa región, así como discutir la influencia del turismo en la difusión del virus en el territorio desde los flujos y circulación masiva de turistas. Metodológicamente, se ha utilizado la investigación cuantitativa-cualitativa y exploratoria y ha presentado como procedimientos el levantamiento bibliográfico, la investigación documental y levantamiento de datos, con el fin de subsidiar el análisis pretendido. Finalmente, se señalan los retos y tendencias de la actividad turística en la región, considerando su dinámica desde las acciones de los principales agentes públicos y privados.

ABSTRACT: Arbuscular mycorrhizal fungi (AMF) are very important to plant nutrition, mostly in terms of acquisition of P and micronutrients. While Acacia mangium is closely associated with AMF throughout the whole cycle, Eucalyptus grandis presents this symbiosis primarily at the seedling stage. The aim of this study was to evaluate the dynamics of AMF in these two tree species in both pure and mixed plantations during the first 20 months after planting. We evaluated the abundance, richness and diversity of AMF spores, the rate of AMF mycorrhizal root colonization, enzymatic activity and soil and litter C, N and P. There was an increase in AMF root colonization of E. grandis when intercropped with A. mangium as well as an increase in the activity of acid and alkaline phosphatase in the presence of leguminous trees. AMF colonization and phosphatase activities were both involved in improvements in P cycling and P nutrition in soil. In addition, P cycling was favored in the intercropped plantation, which showed negative correlation with litter C/N and C/P ratios and positive correlation with soil acid phosphatase activity and soil N and P concentrations. Intercropping A. mangium and E. grandis maximized AMF root colonization of E. grandis and phosphatase activity in the soil, both of which accelerate P cycling and forest performance.

Pasture degradation is a concern, especially in susceptible sandy soils for which strategies to recover them must be developed. Microbiological and biochemical soil health indicators are useful in the guindace of soil management practices and sustainable soil use. We assessed the success of threePanicum maximum Jacq. cultivars in the reclamation of a pasture in a sandy Typic Acrudox in the northwest of the state of Paraná, Brazil, based on soil health indicators. On a formerly degraded pasture withUrochloa brizantha (Hochst. ex A. Rich.) R.D. Webster, a trial with threeP. maximum (cv. Massai, Tanzânia, or Mombaça) was conducted. Lime and phosphate were applied at set-up, and mineral N and K as topdressing. A remnant of degraded pasture adjacent to the trial was used as control. Twenty-three chemical, physical, microbiological and biochemical attributes were assessed for the 0-10 cm topsoil. The procedures for reclamation improved most of the indicators of soil health in relation to the degraded pasture, such as soil P, mineral N, microbial biomass C, ammonification rate, dehydrogenase activity and acid phosphatase. CO2 evolution decreased, whereas microbial biomass C increased in the pasture under reclamation, resulting in a lower metabolic quotient (qCO2) that points to a decrease in metabolic stress of the microbial community. The reclamation of the pasture withP. maximum, especially cv. Mombaça, were evidenced by improvements in the microbiological and biochemical soil health indicators, showing a recovery of processes related to C, N and P cycling in the soil.

Soil Health refers to the ecological equilibrium and the functionality of a soil and its capacity to maintain a well balanced ecosystem with high biodiversity above and below surface, and productivity. To understand and use soil health as a tool for sustainability, physical, chemical, and biological properties must be employed to verify which respond to the soil use and management within a desired timescale. Attributes with a rapid response to natural or anthropogenic actions are considered good indicators of soil health. Among the physical indicators, soil texture, aggregation, moisture, porosity, and bulk density have been used, while among chemical indicators total C and N, mineral nutrients, organic matter, cation exchange capacity, among others are well established. However, most of them generally have a slow response, when compared to the biological ones, such as microbial biomass C and N, biodiversity, soil enzymes, soil respiration, etc., in addition to macro and mesofauna. Thus, a systemic approach based on different kinds of indicators (physical, chemical and biological) in assessing soil health would be safer than using only one kind of attribute. Many human activities have caused desertification, loss of biodiversity, disruption of aggregates, loss of organic matter and nutrients, among others. Today, it is imperious to maintain soil health and productivity with increasing emphasis on reforestation and recuperation of degraded areas through the use of organic amendments, reintroduction of plants, soil fauna and microorganisms. This review focused on an integrative view on indicators of soil health to be used as tools for prediction of sustainability in production systems.