EFFECT OF LIQUID SWINE WASTEWATER DOSES ON PHYSICAL, CHEMICAL AND ELECTROCHEMICAL ATTRIBUTES IN A CERRADO OXISOL. The addition of organic residues enhances soil and plant organic matter and nutrient content. To gauge the impact of varying liquid swine waste (LSW) levels on soil, we studied changes in a clayey Oxisol’s physical, chemical, and electrochemical traits from the Cerrado. LSW doses (0, 50, 150, 450, 600 m3 ha−1) were applied to the 0-0.20 m layer in a randomized design with three replicates. Post a 30-day incubation at 60% field capacity, the soil underwent mineralogical, physical (clay dispersed in water - CDW), chemical (sodium adsorption ratio - SAR, cation exchange capacity - CEC, base saturation - V%), and electrochemical (pH in H2O and KCl, ApH, point of zero charge - PZC, point of zero salt effect - PZSE, surface electric potential - iµo, and electrical conductivity - EC) analyses. The levels of exchangeable Ca, K, Mg, Na, and available P increased with increasing LSW doses. Increasing LSW doses in the soil led to an increase in EC, but soil salinization was not observed at the highest dose. With the application of LSW doses, there was a decrease in pH, ApH, PZSE, and an increase in CEC, PZC and ψo. Despite the increase in ψo, low clay dispersibility was observed. PHYSICAL OXISOL content (LSW Oxisols Oxisol s Cerrado 0, 0 (0 50 150 450 60 ha−1 ha1 ha 1 00.20 0020 0.20 20 0-0.2 replicates 30day day 30 mineralogical CDW, CDW , CDW) sodium SAR CEC V%, V V% V%) pH HO H O KCl ApH PZSE iµo EC analyses Ca K Mg Na dose ψo ( 5 15 45 6 ha− 00 00.2 002 020 0.2 2 0-0. 3 4 00. 02 0. 0-0 0-

Worldwide, millions of people suffer from neurological and psychiatric conditions, such as schizophrenia, depression, and neurodegenerative diseases. These conditions are often linked to hyperactivity of monoamine oxidase B (MAO-B) in the brain, and inhibiting this enzyme can reduce oxidative stress, stabilize neurotransmitter levels, and alleviate symptoms. In this context, a pharmacophoric model was created using PharmaGist with 31 hits extracted from BindingDB to enable a pharmacophoric-based search of potential MAO-B inhibitors in ZincPharmer’s chemical space, followed by the building of 10 conformers for each molecule in the software OMEGA, screening for structural and electrostatic similarity to safinamide using ROCS (Rapid overlay of chemical structures) and EON (Electrostatic similarity for lead-hopping), respectively. In addition, the molecular docking with Gold using the score function was performed to rank the ligands with the highest probabilities of affinity to MAO-B and then discriminate those with suitable physical chemical, pharmacokinetic, and toxicological features using the tools QikProp, SwissADME, and DEREK. Four potential ligands with selective MAO-B inhibitor properties were identified, which show promise as future therapeutic agents for MAO-B-related disorders. Worldwide schizophrenia depression diseases MAOB MAO (MAO-B brain stress levels symptoms context 3 pharmacophoricbased based ZincPharmers ZincPharmer s space 1 OMEGA Rapid structures Electrostatic leadhopping, leadhopping lead hopping , lead-hopping) respectively addition pharmacokinetic QikProp SwissADME DEREK identified MAOBrelated related disorders lead-hopping

High-density polyethylene (HDPE) geomembranes are commonly used as an environmental protection liner due to their good chemical and mechanical resistances and low cost. Ultraviolet (UV) radiation is an essential issue in durability studies for pond applications. This study evaluated a 1.5-mm thick HDPE geomembrane exposed to ultraviolet fluorescent radiation for 8760 h in a laboratory and thermoanalytical and physical analyses were conducted towards the understanding of its performance after exposure. According to the results, although the geomembrane maintained the ductile behavior, it showed a 52.48% final decrease in stress crack resistance (SCR) compared to virgin SCR. Moreover, a considerable antioxidant depletion occurred after 8760 h exposure shown by the Std. OIT (standard oxidative-induction time) results, demonstrating a Std. OIT value decrease of 89.19% compared to the virgin Std. OIT. Such a behavior contributed to the susceptibility of thermal effects in the DSC (differential scanning calorimetry) curves and the losses observed in the SCR values, attesting the geomembrane’s oxidative degradation mechanism occurred and changed the polymer’s structure. Highdensity High density (HDPE cost UV (UV applications 1.5mm 15mm mm 1.5 1 5 876 results 5248 52 48 52.48 (SCR Moreover Std standard oxidativeinduction induction time 8919 89 19 89.19 differential calorimetry values s polymers polymer structure 5mm 15 1. 87 524 4 52.4 891 8 89.1 52. 89.

Groundwater is considered an important source of water aid for human consumption. However, this water can be contaminated by impurities, such contamination spots that might reach the water tables. The aim of this study was to investigate the quality of shallow groundwater in Flores neighborhood, located in the municipality of Benevides, within Belém metropolitan region, State of Pará, Brazil. Recommendations described in Standard Methods for Examination of Water and Wastewater were followed at the time to determine physical-chemical parameters such as potential hydrogen (pH), electrical conductivity (EC), total dissolved solids (TDS), apparent color, turbidity, total hardness (TH), ions and trace elements. Multivariate statistical analysis has shown that most predictive water-quality parameters set for human consumption are associated with natural events involving weathering and leaching processes. Nevertheless, parameters of nitrate, phosphate, EC, TDS and pH are also influenced by anthropic conditions in the surroundings, mainly phosphate and nitrate ions. Therefore, it can be concluded that shallow groundwaters in Flores neighborhood are unsuitable for human consumption, making it necessary for municipal public authorities to take action to solve the problem of water shortage in the borough, thus preventing the population from use those shallow groundwaters, as their consumption can bring health problems. However impurities tables Benevides region Pará Brazil physicalchemical physical chemical pH, , (pH) EC (EC) TDS, (TDS) color turbidity TH, TH (TH) elements waterquality processes Nevertheless surroundings Therefore borough problems (pH (EC (TDS (TH

This study investigated the removal of contaminants in water by adsorption on thermoplastic starch (TPS) and kraft lignin (KL) composites. A study on the desorption of methylene blue (MB) and methyl orange (MO) dyes in water was also carried out, followed by the photodegradation of solutions containing dissolved dyes. Initially, the surface morphology of the TPS and TPS-KL films was analyzed by scanning electron microscopy, revealing advantageous characteristics for efficient adsorption of contaminants. Fourier transform infrared spectroscopy (FTIR) analysis made it possible to characterize the TPS and TPS-KL composites. The results demonstrate the reversibility of the process and confirm the lack of permanent chemical modification in the polymer matrix, indicating that the adsorption/desorption process is physical rather than chemical. This suggests that the adsorbent material can be reused without losing its fundamental structural properties. Furthermore, the study allows for verification of the chemical changes on the surfaces of the materials involved. Ultraviolet-visible spectroscopy (UV-Vis) results show that for MO, both substrates exhibited low adsorption capacity, with efficiency values close to 20%. In contrast, for MB, both composite materials displayed excellent dye adsorption rates, achieving efficiencies of 78% or higher. The photodegradation of adsorbed dyes revealed promising results. (TPS KL (KL composites MB (MB MO (MO out Initially TPSKL microscopy FTIR (FTIR matrix adsorptiondesorption properties Furthermore involved Ultravioletvisible Ultraviolet visible UVVis UV Vis (UV-Vis capacity 20 20% contrast rates 78 higher 2 7

Abstract The improper disposal of this waste poses environmental challenges, which can be addressed through effective reuse strategies. This study aims to explore the potential of utilizing marine shell waste as partial substitutes for aggregates in concrete. The research involves investigating the physical characteristics of the recycled aggregate using Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) techniques to elucidate the contact surface with the paste. Additionally, chemical and mineralogical characteristics are analyzed through X-ray fluorescence and X-ray diffraction tests. The compressive strength test is conducted on concrete samples to assess the performance of these materials as both aggregate (shell type A) and filler (shell type B). The findings indicate that replacing up to 20% of marine shells as coarse aggregate and 10% as filler demonstrates feasibility for applications in structural concrete. Furthermore, up to 30% replacement can be directed towards non-structural concrete, providing a comprehensive understanding of the potential applications of marine shell residues in concrete production. challenges strategies AFM (AFM SEM (SEM paste Additionally Xray X ray tests A B. B . B) 20 10 Furthermore 30 nonstructural non production 2 1 3

Resumo As atividades de mariscagem e malacocultura produzem uma grande quantidade de resíduos sólidos compostos por conchas marinhas. O impacto ambiental do descarte inadequado pode ser atenuado com estratégias de reaproveitamento. O objetivo deste trabalho é investigar a viabilidade do uso de resíduo de conchas marinhas com substituintes parciais de agregados no concreto. As características físicas do agregado reciclado foram investigadas através das técnicas de Microscopia de Força Atômica (MFA) e Microscopia Eletrônica de Varredura (MEV) a fim de esclarecer aspectos da superfície de contato com a pasta; as características químicas e mineralógicas foram investigadas por meio dos ensaios de fluorescência de raios-X e difração de raios-X; e o ensaio de resistência à compressão foi conduzido em amostras de concreto foram moldadas para avaliação do comportamento destes materiais do comportamento destes materiais como agregado (concha tipo A) e fíler (concha tipo B). Concluiu-se que o uso de até 20% de substituição de concha marinha como agregado graúdo e 10% como filer mostrou viabilidade para aplicações em concretos estruturais e, de forma complementar, teores de até 30% podem ser direcionados à concretos não estruturais. reaproveitamento MFA (MFA MEV (MEV pasta raiosX raios X A B. B . B) Concluiuse Concluiu se 20 10 complementar 30 2 1 3

Abstract The use of supplementary cementitious materials to replace Portland clinker is one of the most effective strategies adopted by cement companies to reduce CO 2 emission on large-scale. However, due to the limited availability of traditional materials, alternative options are being investigated. The main objective of this research is to evaluate the characteristics and effect of different replacement levels of cement by dregs and grits on compressive strength. The wastes were ground and particles smaller than 75 µm were used. Chemical and physical were performed to characterize the dregs and grits. For both wastes, replacement levels of 0, 5, 10, 20 and 30% of cement mass were evaluated in the mortar production. The water-cement ratio and superplasticizer admixture content were kept constant. In fresh state, the consistency index and incorporated air content were obtained. Mortars made with dregs had higher strength compared to grits due to the higher combined water content. The results showed that it is possible to replace up to 36% of cement with dregs to obtain a strength of 25 MPa; and 15% for 40 MPa. largescale. largescale large scale. scale large-scale However investigated 7 used 0 5 10 30 production watercement constant state obtained 36 MPa 15 4 1 3

Resumo Ouso de adições minerais em substituição ao clínquer Portland é uma das medidas mitigadoras de emissão de CO2, mais promissoras em larga escala, adotadas pelas cimenteiras. Dada a limitação de disponibilidade de algumas, materiais alternativos vêm sendo investigados. A presente pesquisa teve como objetivo caracterizar e avaliar o efeito de diferentes teores de dregs e grits em substituição parcial ao cimento na resistência à compressão. Os resíduos foram submetidos à moagem, utilizando-se partículas inferiores a 75 µm. Foram realizados ensaios para caracterização química e física dos dregs e grits. Para ambos os resíduos, foram analisados os teores de 0, 5, 10, 20 e 30% em substituição à massa de cimento na produção de argamassas. A relação água/finos e o teor de aditivo superplastificante foram mantidos constantes. No estado fresco, foram avaliados o índice de consistência e o teor de ar incorporado. As argamassas com dregs proporcionaram maior resistência em relação às com grits devido ao maior teor de água combinada. Os resultados mostraram que é possível substituir até 36% do cimento por esse resíduo para obtenção de resistência à compressão de 25 MPa e 15% para 40 MPa. CO2 CO escala cimenteiras algumas investigados moagem utilizandose utilizando se 7 µm 0 5 10 2 30 águafinos finos constantes fresco incorporado combinada 36 15 4 1 3

Summary: The state of Chiapas presents degradation processes of dif ferent kinds, as a consequence of the current established agricultural model. It is estimated that, in the near future, the surface of the state of Chiapas will present more than 55% degradation, generating changes in the physical, chemical and biological properties of the soil, af fecting the quality of life of human beings, mainly due to scarcity of food. The objective of this research was to evaluate the quality of the soils in three municipalities of the central depression of Chiapas, Mexico. The analysis were interpreted taking NOM-021-SEMARNAT-2000 as a reference and were classified according to the world reference base (WRB), version 2014. For the evaluation of soil quality, the sustainable use of land subindex (SUSS). 144 soil samples corresponding to 21 profiles were analyzed. Of the 21 profiles studied, 17 present poor soil qualities, two a sensitive quality, one acceptable quality and one with good quality. Only two soil groups presented good fertility and are classified as Vertisols and Phaeozems, which present good quality and capacity to maintain sustainable agricultural production in this region.

Resumen: El estado de Chiapas presenta procesos de degradación de diferente índole, como consecuencia del actual modelo agrícola establecido. Se estima que, en el futuro cercano, la superficie del estado de Chiapas presente más de 55% de degradación, generando modificaciones en las propiedades físicas, químicas y biológicas del suelo; afectando la calidad de vida de los seres humanos, principalmente por escasez de alimentos. El objetivo de esta investigación fue evaluar la calidad de los suelos en tres municipios de la depresión central de Chiapas, México. Los análisis se interpretaron tomando como referencia la NOM-021-SEMARNAT-2000 y se clasificaron de acuerdo con la world reference base (WRB), versión 2014, para la evaluación de calidad del suelo se utilizó el subíndice de uso sustentable del suelo (SUSS). Se analizaron 144 muestras de suelo correspondientes a 21 perfiles. De los 21 perfiles estudiados, 17 presentan calidad de suelo pobre, dos calidades sensibles, uno calidad aceptable y uno con calidad buena. Solo dos Grupos de suelo presentaron buena fertilidad y son clasificados como Vertisols y Phaeozems, los cuales presentan buena calidad y capacidad para mantener producción agrícola sostenible en esta región.

Resumen: Las Reservas Ecológicas, son la base primordial para la subsistencia de la biodiversidad, desempeñan funciones cruciales para el mantenimiento de los ecosistemas, especialmente, en la preservación de los servicios ecosistémicos de regulación del clima y suministro de agua. Determinar la capacidad de acumulación del COS en tres ecosistemas de la Reserva Ecológica Arenillas (REAR) y la influencia que tienen con los factores de profundidad y el tipo de suelo, fue el objetivo de la investigación. Se partió de la hipótesis que dichos factores ejercen un efecto sobre las propiedades físicas-químicas del suelo, provocando la variabilidad del carbono. Se establecieron 14 unidades de muestreo para los tres ecosistemas; 1) Intervenido, 2) Bosque deciduo y 3) Bosque arbustal deciduo, se extrajo de cada unidad dos muestras de suelo a profundidades de (0-10 y 10-30 cm), dando un total de 28 muestras. Los resultados revelaron diferencias significativas entre los tres tipos de ecosistemas, permitiendo afirmar que, en la REAR, el contenido de COS es mayor en el ecosistema de Bosque deciduo, que en los denominados Bosque arbustal deciduo y la zona Intervenida. Así mismo, los suelos del tipo Alfisol y Entisol en el Bosque deciduo presentaron la mayor capacidad de almacenamiento de COS, siendo la capa superficial la de mayor acumulación en los tres ecosistemas. Se concluyó que las bajas precipitaciones, el aumento de la temperatura y la esporádica vegetación producida por actividades antrópicas, afectan el almacenamiento de COS, limitando la prestación de servicios ecosistémicos relacionados con la captura de carbono edáfico.

Abstract: Ecological Reserves are the primary basis for the subsistence of biodiversity, they play crucial roles in the maintenance of ecosystems, especially in the preservation of ecosystem services of climate regulation and water supply. The objective of the research was to determine the accumulation capacity of COS in three ecosystems of the Arenillas Ecological Reserve (REAR) and the influence of depth factors and soil type. It was hypothesized that these factors exert an effect on the physical-chemical properties of the soil, causing carbon variability. Fourteen sampling units were established for the three ecosystems; 1) Intervened, 2) Deciduous Forest and 3) Deciduous shrub forest, two soil samples were extracted from each unit at depths of (0-10 and 10-30 cm), giving a total of 28 samples. The results revealed significant differences between the three types of ecosystems, allowing us to affirm that, in the REAR, the COS content is higher in the deciduous forest ecosystem than in the deciduous shrub forest and the Intermediate zone. Likewise, Alfisol and Entisol soils in the deciduous forest had the highest COS storage capacity, being the surface layer the one with the highest accumulation in the three ecosystems. It was concluded that low precipitation, increased temperature and sporadic vegetation produced by anthropic activities affect COS storage, limiting the provision of ecosystem services related to soil carbon sequestration.

Abstract The objective of this study is to characterize the industrial solid waste generated by a geopolymeric composites precast industry in Goiás and use them in the production of mortar, in partial replacement of cement in the contents of 5%, 10%, 15% and 25%, due to its probable pozzolanic effect. For the research the residue underwent crushing in a hammer mill and sieving in a #40 mesh conducted in the industry itself. Then, physical-chemical analyzes were conducted to verify if the residue meets the parameters established by NBR 12653 (ABNT, 2014) Pozzolanic Materials - Requirements. The residue showed potential to be used as pozzolana, as in the particle size analysis only 19% was retained on sieve #325 and the moisture content also met the parameters of the aforementioned standard. However, the fire loss content and the alkali content available in ���� 2 �� were higher than the standard requirements, because the residue contains tire shavings and sodium hydroxide (NaOH) in its composition. In relation to the performance index with Portland cement at 28 days, the mortar with 5% residue in its composition met the standard conditions, but the performance with lime did not obtain the desired result, as the resistance decreased. After analysis, it has been realized that the residue does not qualify as pozzolan but can be used as a filler. 5 10 10% 15 25 25% effect 40 #4 itself Then physicalchemical physical chemical 1265 ABNT, ABNT (ABNT 2014 Requirements pozzolana 19 325 #32 However ��� � requirements NaOH (NaOH days conditions result decreased filler 1 4 # 126 201 32 #3 12 20 3

Resumo O objetivo deste estudo é caracterizar os resíduos sólidos industriais gerados por uma indústria goiana de pré-moldados de compósitos geopoliméricos e utilizá-los na produção de argamassa, em substituição parcial ao cimento nos teores de 5%, 10%, 15% e 25%, devido ao seu provável efeito pozolânico. Para a pesquisa o resíduo passou por trituração em moinho martelo e peneiramento em malha #40 realizados na própria indústria. Em seguida, foram realizadas análises físico-químicas para verificar se o resíduo atende aos parâmetros estabelecidos pela NBR 12653 (ABNT, 2014b) Materiais Pozolânicos - Requisitos. O resíduo apresentou potencial para ser utilizado como pozolana, pois na análise granulométrica apenas 19% ficaram retidos na peneira #325 e o teor de umidade também atendeu aos parâmetros da referida norma. No entanto o teor de perda ao fogo e o teor de álcalis disponíveis em Na 2 �� foram maiores do que os requisitos da norma, devido ao fato de o resíduo possuir em sua composição, raspas de pneu e hidróxido de sódio (NaOH). Em relação ao índice de desempenho com cimento Portland aos 28 dias, a argamassa que possui em sua composição 5% de resíduo atendeu as condições da norma, mas o desempenho com cal não obteve o resultado desejado, pois a resistência diminuiu. Após análise, percebeu-se que o resíduo não se enquadra como pozolana, mas pode ser usado como enchimento. prémoldados pré moldados utilizálos utilizá los 5 10 10% 15 25 25% pozolânico 40 #4 seguida físicoquímicas físico químicas 1265 ABNT, ABNT (ABNT 2014b b Requisitos pozolana 19 325 #32 norma � NaOH. NaOH . (NaOH) dias desejado diminuiu percebeuse percebeu enchimento 1 4 # 126 32 #3 (NaOH 12 3

Abstract Introduction: Reservoirs are conceived as a set of interactions in which physical, chemical, and biological instability determines changes in the density of planktonic communities. Objective: To evaluate the instability of phytoplankton and zooplankton, and their interactions with environmental factors in four tropical Andean reservoirs with different trophic status. Methods: Physical and chemical variables and phytoplankton and zooplankton densities were measured between 2010-2018 in the oligotrophic reservoirs Punchiná and San Lorenzo and between 2013 and 2015 in the hypereutrophic reservoir Porce II and in the eutrophic Porce III reservoir (total N = 248). The Factor Shaping Community Assemblages (FCA) was used to calculate environmental and biotic instability as well as their interaction. Results: High environmental and biological instability was observed in the studied reservoirs. Oxygen saturation, pH, total nitrogen, water temperature, nitrites, total phosphorus (only for zooplankton), and total solids were the abiotic variables with the greatest contribution to planktonic instability, regardless of trophic state. Particularly, Cryptomonas sp., Aulacoseira sp., Cyclotella sp., Dinobryon sp., Nephrocytium sp., Tetraëdron caudatum and Oscillatoria sp. had the greatest influence on the instability of various rotifer taxa and some copepods. Conclusions: Regardless of trophic state, pH dynamics, nutrients availability, amount of suspended solids and the availability of gases, such as dissolved oxygen, mainly determined the instability of phytoplankton and to a lesser extent that of zooplankton. In the oligotrophic reservoirs, zooplankton instability was mainly influenced by highly palatable algae with no toxicity, and in reservoirs highly enriched, the instability was influenced by algae with low nutritional quality and difficult to ingest and manipulate.

Resumen Introducción: los embalses deben ser concebidos como un conjunto de interacciones, donde la inestabilidad física, química y biológica determinan cambios en la densidad de las comunidades planctónicas. Objetivo: Evaluar la inestabilidad del fitoplancton y zooplancton y su interacción con factores ambientales en cuatro embalses tropicales andinos con diferente estado trófico. Métodos: Se analizaron datos de variables físicas y químicas y de las densidades del fitoplancton y del zooplancton, medidas entre 2010-2018, en los embalses oligotróficos Punchiná y San Lorenzo y, entre 2013 y 2015, en el embalse hipereutrófico Porce II y en el embalse eutrófico Porce III (total N = 248). Se empleó el Factor Shaping Community Assemblages (FCA), para calcular la inestabilidad biótica y ambiental y la interacción entre estas. Resultados: En los embalses estudiados hubo una alta inestabilidad ambiental y biológica. El pH, la saturación de oxígeno, el nitrógeno total, la temperatura del agua, los nitritos, el fósforo total (solo para el zooplancton) y los sólidos totales, son las variables abióticas con mayor aporte a la inestabilidad planctónica, independientemente del estado trófico. Particularmente, Cryptomonas sp., Aulacoseira sp., Cyclotella sp., Dinobryon sp., Nephrocytium sp., Tetraëdron caudatum y Oscillatoria sp., tuvieron mayor influencia sobre la inestabilidad de diferentes taxones de rotíferos y de algunos copépodos. Conclusión: Independiente del estado trófico, la dinámica del pH, la disponibilidad de nutrientes, la cantidad de sólidos suspendidos y la disponibilidad de gases como el oxígeno disuelto determinaron principalmente la inestabilidad del fitoplancton, y en menor medida la del zooplancton. En los embalses oligotróficos la inestabilidad del zooplancton es influenciada principalmente por algas altamente apetecibles con toxicidad nula, y en embalses altamente enriquecidos la inestabilidad fue influenciada por algas con baja calidad nutricional y de difícil ingestión y manipulación.

Abstract Introduction: Blooms of cyanobacteria are becoming increasingly common, and understanding their dynamics can be crucial for proposing appropriate management strategies. While physical and chemical parameters influencing blooms have been widely studied, less attention has been paid to the susceptibility of biological communities. Objective: To analyze phytoplankton abundance networks during cyanobacterial blooms at different intensity levels and how they interact and/or affect the phytoplankton community. Methods: We used 22 samplings conducted in El Limón reservoir located in Northern Argentina, known for recurrent cyanobacterial blooms. Each sampling was classified into four levels based on cyanobacteria abundance (cells/ml): Level 1 (10 000-30 000); Level 2 (30 000-50 000); Level 3 (50 000-100 000); and Level 4 (> 100 000). For each level, abundance correlation networks were constructed considering all species. Results: A pattern of decreasing statistically significant abundance correlations was observed as bloom intensity increased: 219 correlations at Level 1; 144 at Level 2; 80 at Level 3, and only 33 at Level 4. Blooming cyanobacteria showed few correlations with other species at all levels, indicating a certain independence from the community. An increase in bloom intensity appears to disconnect the phytoplankton abundance correlation network. Conclusion: The analysis of abundance correlation networks should be a valuable tool for understanding the dynamics and development of cyanobacterial blooms, as well as identifying key species in this process.

Resumen Introducción: Las proliferaciones de cianobacterias están volviéndose cada vez más comunes, y comprender su dinámica puede ser crucial para proponer estrategias de gestión adecuadas. Si bien se han estudiado ampliamente los parámetros físicos y químicos que influyen en las proliferaciones, se ha prestado menos atención a la susceptibilidad de las comunidades biológicas. Objetivo: Analizar las redes de abundancia de fitoplancton durante las proliferaciones de cianobacterias a diferentes niveles de intensidad y cómo las mismas interactúan y/o afectan a la comunidad de fitoplancton. Métodos: Se realizaron 22 muestreos en el embalse El Limón ubicado en el norte de Argentina, conocido por las proliferaciones recurrentes de cianobacterias. Cada muestreo se clasificó en cuatro niveles basados en la abundancia de cianobacterias (células/ml): Nivel 1 (10 000-30 000); Nivel 2 (30 000-50 000); Nivel 3 (50 000-100 000) y Nivel 4 (> 100 000). Para cada nivel, se construyeron redes de correlación de abundancias considerando todas las especies. Resultados: Se observó un patrón de disminución de correlaciones de abundancia estadísticamente significativas a medida que aumentaba la intensidad de las proliferaciones: 219 correlaciones en el nivel 1; 144 en el nivel 2; 80 en el nivel 3 y solo 33 en el nivel 4. Las cianobacterias que forman proliferaciones mostraron tener poca correlación con otras especies en todos los niveles, lo que podría estar asociado a cierta independencia con respecto a la comunidad. Un aumento en la intensidad de la proliferación parece desconectar la red de correlaciones de abundancia del fitoplancton. Conclusión: El análisis de las redes de correlaciones de abundancias debería ser una herramienta valiosa para comprender la dinámica y el desarrollo de las proliferaciones de cianobacterias, así como para identificar especies clave en este proceso.

ABSTRACT Inadequate grassland management has resulted in the degradation of extensive areas, loss of productivity and sustainability of many of them, reflecting a common reality among livestock farmers in Colombia. Therefore, at the Paysandú Agricultural Station of the Universidad Nacional de Colombia, located in the Santa Elena township of the city of Medellín, a study was carried out to determine a soil quality index (SQI) by evaluating the physical and chemical indicators that were most related to the deterioration and dry matter production of kikuyu grass (Cenchrus clandestinus). A minimum data set (MDS) was established for the most sensitive indicators, selected by principal component analysis (PCA), and a nonlinear scoring function was used to obtain the SQI. Statistical differences were found between all the treatments in relation to dry matter production (P<0.05: 1.91x10-32). The most sensitive indicators were bulk density BD > total porosity TP > macropores MAC > micropores MIC > penetration resistance PR > effective cation exchange capacity ECEC > pH. As a result, the following formula was obtained: SQI = (0.225×BD) + (0.224×TP) + (0.220×MAC) + (0.218×MIC) + (0.113×PR) + (0.0879×ECEC) + (0.0877×pH). This index should be tested in kikuyu grass-dominated pastures located in the Colombian high tropics. The baseline is critical at values > 0.58 Mg m-3 for BD and > 2.25 MPa for PR. In addition, the optimum pH range for kikuyu grass development was between 5.4 and 6.4.

RESUMEN El manejo inadecuado de los pastizales ha provocado la degradación de extensas áreas, la pérdida de productividad y sostenibilidad de muchas de ellas, reflejando una realidad común entre los ganaderos de Colombia. Por ello, en la Estación Agraria Paysandú de la Universidad Nacional de Colombia, ubicada en el corregimiento de Santa Elena de la ciudad de Medellín, se realizó una investigación para determinar un índice de calidad del suelo (SQI) mediante la evaluación de los indicadores físicos y químicos más relacionados con el deterioro y producción de materia seca del pasto kikuyo (Cenchrus clandestinus). Se estableció un conjunto mínimo de datos (MDS) para los indicadores más sensibles, elegidos mediante el análisis de componentes principales PCA, y se utilizó una función de puntuación no lineal para obtener el SQI. Se encontraron diferencias estadísticas entre todos los tratamientos y la producción de materia seca (P<0,05: 1,91x10-32). Los indicadores más sensibles fueron: densidad aparente DR > porosidad total TP > macroporos MAC > microporos MIC > resistencia a la penetración PR > capacidad de intercambio catiónico efectiva ECEC > pH. Como resultado, se obtuvo el siguiente SQI = (0,225×BD) + (0,224×TP) + (0,220×MAC) + (0,218×MIC) + (0,113×PR) + (0,0879×ECEC) + (0,0877×pH). Se sugiere probar el índice en praderas dominadas por pasto kikuyo ubicadas en el trópico alto colombiano. La línea de base es crítica a valores > 0,58 Mg m-3 para BD y > 2,25 MPa para PR. Además, el intervalo de pH óptimo para el desarrollo del pasto kikuyo se situó entre 5,4 y 6,4.

Abstract Fermentation in a solid medium is a technique used for the production of chitin, pigments, proteins and lipids. In the present work, changes in the chemical and microbiological composition were evaluated in micro silages of shrimp (Litopeneus vanamei) and grasshopper (Sphenarium purpurascens) exoskeletons, fermented with a commercial inoculum of Lactobacillus plantarum AVG-112. The amount of molasses for fermentation, proximal composition and microbiological count of the silages, were determined. The waste was mixed with sugarcane molasses as a carbon source and inoculated using a commercial strain (Lactobacillus plantarum AVG-112). After 5 days of fermentation, both silages presented acceptable physical and chemical characteristics. Total coliforms, molds and yeasts were not present and were inhibited by the ensiling process. We concluded that fermentation in a solid medium has suitable characteristics for use as a food supplement for aquatic organisms.

Resumen La fermentación en medio sólido es una técnica utilizada para la producción de quitina, pigmentos, proteínas y lípidos. En el presente trabajo se evaluaron los cambios en la composición química y microbiológica en micro ensilados de exoesqueletos de camarón (Litopeneus vanamei) y chapulín (Sphenarium purpurascens) fermentados con un inoculo comercial de Lactobacillus plantarum AVG-112. Se determinó la cantidad de melaza para la fermentación, la composición proximal y la cuenta microbiológica de los ensilados. Los desechos se mezclaron con melaza de caña de azúcar como fuente de carbono y se inoculó usando una cepa comercial (Lactobacillus plantarum AVG-112). A los 5 d de fermentación ambos ensilados presentaron características físicas y químicas aceptables. Los coliformes totales, mohos y levaduras no estuvieron presentes siendo inhibidos por el proceso de ensilaje. Concluimos que la fermentación en medio sólido tiene características adecuadas para su utilización como suplemento en alimentos para organismos acuáticos.

ABSTRACT Potassium is a nutrient with the potential to increase plant tolerance to salt stress. The aim of this study was to evaluate the production and quality of kale subjected to salt stress and potassium concentrations in a protected environment. The experimental design was in split plots, with plots composed of five nutrient solutions (control treatment, S1 - standard nutrient solution prepared in low-salinity water, 0.5 dS m-1 (500 mg L-1 of KNO3), and four nutrient solutions prepared in brackish waters (3.5 dS m-1) containing four concentrations of KNO3 (S2 - 500 mg L-1, S3 - 625 mg L-1, S4 - 750 mg L-1, S5 - 1,000 mg L-1), and subplots represented by two leaf kale cultivars (Manteiga and Manteiga da Geórgia). Leaf production variables and post-harvest physical and chemical qualities were evaluated. The saline nutrient solution with the addition of NaCl (S2) reduced production but did not reduce the post-harvest quality of kale. The extra addition of KNO3 at 25% (S3) was efficient in reducing the deleterious effects of salt stress on the variables leaf length, leaf area, leaf production, and number of bunches. The cv. Manteiga da Geórgia was more tolerant to salt stress than the cv. Manteiga. environment control treatment S lowsalinity low salinity water 05 0 5 0. m1 m 1 m- (50 L1 L L- KNO3, KNO , KNO3) 3.5 35 3 (3. S2 (S 50 L1, 1, 62 75 1000 000 1,00 L-1) Geórgia. . Geórgia) postharvest post harvest evaluated 25 (S3 length area bunches cv (5 3. (3 6 7 100 00 1,0 2 ( 10

RESUMO O potássio é um nutriente com potencial para aumentar a tolerância das plantas ao estresse salino. O objetivo deste estudo foi avaliar a produção e a qualidade da couve submetida ao estresse salino e às concentrações de potássio em ambiente protegido. O delineamento experimental adotado foi em parcela subdivididas, sendo as parcelas compostas por cinco soluções nutritivas (tratamento controle, S1 - solução nutritiva padrão usando água de baixa salinidade, 0,5 dS m-1 (500 mg L-1 de KNO3), e quatro soluções nutritivas preparadas em águas salobras (3,5 dS m-1) contendo quatro concentrações de KNO3 (S2 - 500 mg L-1, S3 - 625 mg L-1, S4 - 750 mg L-1, S5 - 1.000 mg L-1). As subparcelas foram representadas por duas cultivares de couve folha (Manteiga e Manteiga da Geórgia). Foram avaliadas as variáveis de produção de folhas e qualidades físicas e químicas pós-colheita. A solução nutritiva salinizada com adição de NaCl (S2) reduziu a produção, mas não reduziu a qualidade pós-colheita da couve folha. A adição extra de KNO3 em 25% (S3) foi eficiente para reduzir o efeito deletério do estresse salino sobre as variáveis comprimento de folha, área foliar, produção e número de maços. A cv. Manteiga da Geórgia se mostrou mais tolerante ao estresse salino que a cv. Manteiga. protegido subdivididas tratamento controle S salinidade 05 0 5 0, m1 m 1 m- (50 L1 L L- KNO3, KNO , KNO3) 3,5 35 3 (3, S2 (S 50 L1, 1, 62 75 1000 000 1.00 L1. . L-1) Geórgia. Geórgia) póscolheita. póscolheita pós colheita. colheita 25 (S3 foliar maços cv (5 3, (3 6 7 100 00 1.0 2 ( 10 1.