Resumen Introducción. La enfermedad de la necrosis aguda del hepatopáncreas (AHPND, por sus siglas en inglés) es producida por bacterias Vibrio parahaemolyticus que poseen un plásmido con genes que codifican las toxinas pirA y pirB. La enfermedad se caracteriza por descamación masiva de las células epiteliales del hepatopáncreas, así como la atrofia y decoloración de ese órgano. Los camarones enfermos presentan anorexia y muestran un intestino vacío, debilidad, decoloración del cuerpo y altas mortalidades. Objetivo. Determinar la prevalencia de Vibrio parahaemolyticus causante de AHPND en fincas de camarones en la zona del Pacífico de Costa Rica. Materiales y métodos. Durante los años 2019 y 2020, se recolectaron camarones (Penaeus vannamei) y agua de estanques de 32 fincas localizadas en la costa occidental del golfo de Nicoya (noroeste del país) y la costa del Pacífico Central (Puntarenas-Parrita). Los camarones recolectados en los muestreos tenían un peso de entre 7 y 15 g. El diagnóstico de la presencia de la enfermedad se analizó a nivel molecular con la reacción en cadena de la polimerasa (PCR) punto final, y diferentes protocolos e iniciadores para detectar los genes de las toxinas pirA y pirB. Además, se hizo una correlación lineal entre la presencia de AHPND y la calidad del agua con el programa estadístico R. Resultados. La presencia de Vibrio parahaemolyticus causante de AHPND ocurrió en 93,75 % (30/32) de los estanques muestreados en ambas zonas de cultivo. Conclusiones. Este trabajo confirma la presencia y amplia distribución de AHPND en agua y camarones en treinta fincas camaroneras en el Pacífico de Costa Rica.

Abstract Introduction. The acute hepatopancreas necrosis disease (AHPND) is caused by bacteria Vibrio parahaemolyticus containing a plasmid encoding the toxin genes pirA and pirB. The disease is characterized by massive sloughing of epithelial cells in the hepatopancreas, also showing atrophy and discoloration of that organ. Diseased shrimp display anorexia with empty guts, weakness, body discoloration and high mortality. Objective. To determine the prevalence of Vibrio parahaemolyticus causing AHPND in farms that grow shrimp in the Pacific zone of Costa Rica. Materials and methods. During the years 2019 and 2020, water and shrimp (Penaeus vannamei) samples were obtained from 32 farms located on the western coast of the Nicoya Gulf (Northwest Costa Rica) and the Central Pacific coast (Puntarenas-Parrita). The samples were analyzed by endpoint polymerase chain reaction (PCR) using different protocols and primers to detect the toxins pirA and pirB. Further, a linear correlation between the presence of AHPND and water quality was done using the R statistical program. Results. The presence of Vibrio parahaemolyticus causing AHPND occurred in 93.75 % (30/32) of sampled ponds in both farming areas. Conclusion. This work confirms the presence and wide distribution of AHPND in water and shrimp from thirty shrimp farms in the Costa Rican Pacific.

Resumen (Introducción): El agua es esencial para todos los seres vivos, ya que facilita el transporte de nutrientes, la eliminación de desechos y la regulación de la temperatura corporal. El agua subterránea es la principal fuente para el consumo de ganado bovino y la falta de aquella de buena calidad puede impactar negativamente en su salud, reproducción y productividad. En Argentina, la ganadería bovina para la producción de carne y leche es una actividad económica clave, por lo que resulta crucial garantizar un suministro de agua adecuado en cantidad y calidad. (Objetivo): Evaluar la calidad del agua subterránea para el ganado en la cuenca lechera de Santa Fe, Argentina, utilizando un índice de calidad de agua adaptado para bovinos. (Metodología): Durante el periodo 2023-2024, se recolectaron muestras de agua subterránea en una de las principales cuencas lecheras del país. Se analizaron parámetros significativos para la calidad del agua destinada al consumo bovino, tales como pH, sólidos disueltos totales, sulfato, cloruro, nitrato y arsénico. Cada parámetro recibió una valoración basada en sus efectos perjudiciales para los animales y, mediante una ecuación matemática, se clasificó la calidad del agua desde muy buena hasta extremadamente pobre. (Resultados): El estudio reveló que un alto porcentaje de las muestras de la cuenca lechera presentan una calidad buena o muy buena, aunque también se identificaron pozos con calidad deficiente. (Conclusiones): Los resultados subrayan la importancia de monitorear y gestionar la calidad del agua subterránea, para asegurar una ganadería bovina sostenible en la cuenca lechera de Santa Fe.

Abstract (Introduction): Water is essential for all living beings as it facilitates nutrient transfer, waste elimination, and body temperature regulation. Groundwater is the primary source for bovine livestock consumption, and poor-quality water can negatively affect their health, reproduction, and productivity. In Argentina, bovine farming for meat and milk production is a significant economic activity, making it crucial to ensure an adequate supply of water in both quantity and quality. (Objective): This study aims to evaluate groundwater quality for cattle in the Santa Fe dairy basin, Argentina, using a water quality index adapted for bovines. (Methodology): During the 2023-2024 period, groundwater samples were collected from one of the main dairy basins in the country. Parameters significant to water quality for bovine consumption, such as pH, total dissolved solids, sulfate, chloride, nitrate, and arsenic, were analyzed at each monitored well. Each parameter was assigned a score based on its harmful effects on livestock, and a mathematical equation was applied to classify water quality from very good to extremely poor. (Results): The study revealed that a high percentage of samples in the dairy basin are of good or very good quality, although wells with poor water quality were also identified. (Conclusions): The findings highlight the importance of monitoring and managing groundwater quality to ensure sustainable bovine farming in the Santa Fe dairy basin.

Resumen Introducción. El girasol silvestre o polocote (Helianthus annuus L.) es la principal maleza anual en el cultivo de sorgo y maíz en el norte de Tamaulipas, México. Existe escasa información sobre esta especie para realizar bioensayos con herbicidas. Objetivo. Establecer una metodología para la obtención de plántulas de polocote para bioensayos con herbicidas, desde la semilla hasta la multiplicación en vivero. Materiales y métodos. La semilla de polocote se recolectó en enero del año 2023, en el Campo Experimental del Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP), en Río Bravo, Tamaulipas. Después, se ejecutó la prueba de germinación inicial sobre papel filtro y viabilidad con tetrazolio. Se comprobó latencia por baja germinación (12 %) y alta viabilidad (86 %). Se usaron doce tratamientos para romper la latencia, mediante etanol (70 %) y agua (75, 25). Como control se utilizó solamente agua. Los tratamientos se aplicaron a temperaturas de 5 °C y 20 °C, sobre papel filtro, algodón y peat moss, en cajas Petri durante siete días. Posteriormente, se mantuvieron a una temperatura de ±25 °C. Con los resultados anteriores, se estableció la fase de vivero con cuatro esquemas con trasplante de semilla pregerminada y dos con siembra directa. Resultados. El mejor tratamiento para romper latencia fue inmersión en agua a 5 °C por siete días sobre algodón, con una germinación del 73 %. Los mejores métodos para obtener plantas fueron charolas con plántulas y trasplante en macetas negras con 75 % y 50 % de supervivencia, respectivamente. La sombra inhibió el crecimiento de las plantas. La siembra directa, con o sin prehidratación de la semilla, fue desfavorable para la germinación y emergencia. Conclusión. La obtención de plántulas de girasol silvestre fue superior cuando la semilla se sometió a pretratamiento hídrico y trasplante posterior a charolas o a bolsas.

Abstract Introduction. The wild sunflower or polocote (Helianthus annuus L.) is the main annual weed in the cultivation of sorghum and corn in northern Tamaulipas, Mexico. To date, there is little information about this species to carry out bioassays with herbicides. Objective. Establish a methodology for obtaining polocote seedlings for bioassays with herbicides, from seed to multiplication in the nursery. Materials and methods. The polocote seed was collected in January 2023, within the National Institute of Forestry, Agriculture and Livestock Research (INIFAP) Experimental Field, in Río Bravo, Tamaulipas. Afterwards, the initial germination test was carried out on filter paper and viability with tetrazolium. Latency was confirmed due to low germination (12 %) and high viability (86 %). Twelve treatments were used to break dormancy using ethanol (70 %) and water (75, 25). As a control only water were used. The treatments were applied at temperatures of 5 °C and 20 °C, on filter paper, cotton, and peat moss in Petri dishes for seven days. Subsequently, they were kept at a temperature of ±25 °C. With the previous results, the nursery phase was established with four schemes with pre-germinated seed transplantation and two with direct sowing. Results. The best treatment to break dormancy was immersion in water at 5 °C for seven days on cotton, with 73 % germination. The best methods to obtain plants were trays with seedlings and transplanting into black open-air pots, with 75 % and 50 % survival, respectively. Shade inhibited plant growth. Direct sowing, with or without seed prehydration, was unfavorable for germination and emergence. Conclusion. Obtaining wild sunflower seedlings was higher when the seed was subjected to water pre-treatment and subsequent transplanting into trays or open-air bags.

RESUMO O objetivo deste trabalho foi avaliar as características produtivas e a eficiência do uso da terra e da água em monocultivo e consórcio de rúcula com jambu sob regimes hídricos em dois ciclos de cultivo em região semiárida do Ceará. O delineamento experimental foi em blocos casualizados, em esquema de parcelas subdivididas, com 20 tratamentos e quatro repetições. As parcelas foram as irrigações, com 50, 75, 100, 125 e 150% de ETc. As subparcelas foram os sistemas consorciado e solteiro. Em cada ciclo foram avaliadas as características de crescimento das plantas e a eficiência do uso da água e da terra. Os maiores valores foram obtidos para número de folhas, altura, e massa fresca e seca das partes aéreas e raízes das plantas de rúcula quando consorciadas. Os melhores resultados para as variáveis de crescimento do jambu foram obtidos para as plantas cultivadas em monocultivo. Os valores de produtividade foram maiores no sistema solteiro; entretanto, os valores médios de eficiência do uso da terra no sistema consorciado foram de 1,23 e 1,28 em 2018 e 2019, respectivamente. Os melhores resultados foram obtidos com 75% ETc (DI75) para rúcula e irrigação total com 100% ETc (TI100) e irrigação em excesso com 125% ETc (EI125) para jambu. A eficiência do uso da água foi maior no sistema solteiro. Os índices de produtividade obtidos com o sistema consorciado rúcula-jambu e DI75 confirmam a maior eficiência biológica. Com base no exposto, conclui-se que rúcula e jambu são promissores para o consórcio em condições semiáridas.

ABSTRACT The objective of this study was to evaluate the production characteristics and the efficiency of land and water use in monoculture and intercropping of arugula with jambu under water regimes in two crop cycles in the semi-arid region of Ceará, Brazil. The experimental design was randomized blocks, in a split-plot scheme, with 20 treatments and four replicates. The plots were irrigation, corresponding to 50, 75, 100, 125 and 150% of ETc. The subplots were the intercropping and single systems. In each cycle, the growth characteristics of the plants and the efficiency of water and land use were evaluated. The highest values were obtained for number of leaves, height, and fresh and dry mass of aerial parts and roots of arugula plants when intercropped. The best results for the growth variables of jambu were obtained for plants grown in monoculture. The productivity values were higher in the single-cropping system; however, the average land use efficiency values in the intercropped system were 1.23 and 1.28 in 2018 and 2019, respectively. The best results were obtained with 75% ETc (DI75) for arugula and full irrigation with 100% ETc (TI100) and excess irrigation with 125% ETc (EI125) for jambu. Water use efficiency was higher in the single system. The productivity indices obtained with the arugula-jambu intercropped system and DI75 confirm the higher biological efficiency. Based on the above, it is concluded that arugula and jambu are promising for intercropping under semi-arid conditions.

RESUMO O conteúdo de água no solo é um fator-chave na avaliação nas áreas agrícola e ecológica. O objetivo deste trabalho foi explorar a combinação de informações multisatélites para abordar a questão da baixa precisão na recuperação do conteúdo de água do solo a partir de informações de banda única e fonte única, e estabelecer um modelo para estimativa do conteúdo de água do solo baseado no método multiespectral simulado. Foi realizado um experimento de determinação hiperespectral de amostras de solo (Latossolos) com valores variáveis de teor de água. A reflectância de oito sensores de satélite multiespectral foi remapeada com base nas funções de resposta espectral. Os índices de vegetação (VIs) foram estabelecidos combinando todas as bandas de sensores disponíveis. Os VIs significativos e a reflectância da banda foram extraídos pelos métodos de coeficiente de correlação e análise de importância de dados out-of-bag (OOB), e em seguida modelos lineares e não lineares foram estabelecidos para a estimativa do conteúdo de água no solo. Correlação significativa foi obtida entre refletância multiespectral simulada, VIs e teor de água no solo. Os modelos não lineares apresentaram melhor desempenho que o modelo linear. A combinação do modelo OOB e Random Forest (OOB-RF) obteve a maior acurácia de predição, com R2 calibração e R2 predição de 0,852 e 0,834, respectivamente. De forma geral, verificou-se que o método de modelagem OOB-RF baseado em sensoriamento remoto multiespectral foi viável para estimar o teor de água no solo.

ABSTRACT The soil water content is a key evaluation factor in the agricultural and ecological fields. The objective of this study was to explore the combination of multi-satellite information to address the issue of low accuracy in soil water content retrieval from single-band, single-source information and to establish a model for the estimation of the soil water content based on a simulated multi-spectral method. An experiment involving the hyperspectral determination of soil samples (Oxisols) with varying values of the water content was conducted. The reflectance of eight multi-spectral satellite sensors was resampled based on the spectral response functions. The vegetation indices (VIs) were established by pairing all available sensor bands. The significant VIs and band reflectance were extracted using the correlation coefficient and out-of-bag (OOB) data importance analysis methods, and then linear models and nonlinear models were established for soil water content estimation. A significant correlation was achieved between the simulated multi-spectral reflectance, VIs, and soil water content. The nonlinear models had a better performance than the linear model. The combined OOB and random forest (OOB-RF) model achieved the highest prediction accuracy, with R2 calibration and R2 prediction values of 0.852 and 0.834, respectively. Overall, it was verified that the OOB-RF modeling method based on multi-spectral remote sensing was feasible for estimating the soil water content.

RESUMO O uso de águas com alta concentração de sais no cultivo do cajueiro se faz necessário na região semiárida do Nordeste brasileiro, devido à escassez hídrica e à má distribuição das chuvas. O excesso de sais na água é um fator limitante para a produção agrícola. Nesse cenário, estratégias têm sido empregadas para mitigar os efeitos nocivos do estresse salino sobre as plantas, destacando-se o uso do ácido salicílico. Com isso, o objetivo deste trabalho foi avaliar os efeitos da aplicação foliar de ácido salicílico sobre os aspectos fisiológicos e crescimento do cajueiro anão precoce cultivado sob estresse salino na fase de pré-floração. O experimento foi conduzido em casa de vegetação utilizando o delineamento em blocos casualizados, em arranjo fatorial 5 × 4, com cinco níveis de condutividade elétrica da água de irrigação (CEa - 0,4; 1,2; 2,0; 2,8 e 3,6 dS m-1) e quatro concentrações de ácido salicílico - AS (0, 1, 2 e 3 mM), com três repetições. O ácido salicílico, aplicado na concentração de 1 mM, atenuou os efeitos do estresse salino na morfofisiologia do cajueiro durante a fase de pré-floração, especialmente em plantas irrigadas com CEa de até 1,2 dS m-1. Por outro lado, a concentração de 3 mM AS elevou os efeitos negativos do estresse salino no teor relativo de água, extravasamento de eletrólitos, pigmentos fotossintéticos, trocas gasosas e crescimento de cajueiro anão precoce, particularmente em CEa de 3,6 dS m-1.

ABSTRACT The use of water with high concentration of salts in cashew cultivation is a necessity in the semi-arid region of Northeast Brazil, due to water scarcity and poor rainfall distribution. Excess salts in water are a limiting factor for agricultural production. In this scenario, strategies have been employed to mitigate the harmful effects of salt stress on plants, and the use of salicylic acid stands out. With this, the aim of this study was to evaluate the effects of foliar application of salicylic acid on the physiology and growth of early dwarf cashew grown under salt stress in the pre-flowering stage. The experiment was conducted in a greenhouse using a randomized block design, in a 5 × 4 factorial arrangement, with five levels of electrical conductivity of irrigation water (ECw - 0.4, 1.2, 2.0, 2.8, and 3.6 dS m-1) and four concentrations of salicylic acid (SA - 0, 1, 2, and 3 mM), with three replicates. Salicylic acid, applied at a concentration of 1 mM, mitigated the negative impacts of salt stress on the morphophysiology of cashew during the pre-flowering phase, especially in plants irrigated with ECw of up to 1.2 dS m-1. On the other hand, the concentration of 3 mM SA exacerbated the effects of salt stress on the relative water content, electrolyte leakage, photosynthetic pigments, gas exchange, and growth of early dwarf cashew, particularly at ECw of 3.6 dS m-1.

ABSTRACT Introduced fish can threaten aquatic biodiversity. Peru is a megadiverse country; its northern coast (Tumbes, Piura, Lambayeque, and La Libertad) exhibits greater fish diversity than its central and southern regions. In this area, introduced species exist; however, no research has been found that consolidates data on them. The aim of this research was to prepare a systematic review of introduced and potentially invasive fish in the northern coast of Peru. Following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) from 2020, 2,665 documents were obtained from Scopus, WoS, ScienceDirect, SciELO, PubMed, and Google Scholar. After removing duplicate documents and applying inclusion and exclusion criteria, six documents were selected. Eight additional documents were obtained from other sources. A total of 12 introduced species were reported: common carp (Cyprinus carpio), gambusia (Gambusia affinis), guppy (Poecilia reticulata), swordtail (Xiphophorus hellerii), tilapia (Coptodon rendalli), blue tilapia (Oreochromis aureus), Mozambique tilapia (Oreochromis mossambicus), Nile tilapia (Oreochromis niloticus), wami tilapia (Oreochromis urolepis), cobia (Rachycentron canadum), rainbow trout (Oncorhynchus mykiss), and hypostomus (Hypostomus sp.). Of these, five species were cichlids and three were poeciliids; eleven species were found in freshwater, five in mangroves, and two in the sea. Tumbes recorded the highest number of waterbodies with introduced species, Piura recorded the highest number of species (eight), while Lambayeque reported only one species in a waterbody. Seven species (common carp, gambusia, guppy, tilapias - blue, Mozambique, and Nile - and rainbow trout) have a high invasive potential, as they are among the 100 worst invasive species in Europe or worldwide. The evaluated documents have only reported the presence of introduced species without delving into their impact on ecosystems; therefore, further research in this direction would be advisable.

RESUMEN Los peces introducidos pueden amenazar a la biodiversidad acuática. Perú es un país megadiverso; su costa norte (Tumbes, Piura, Lambayeque y La Libertad) presenta una mayor diversidad íctica que su centro y sur. En esta región existen especies introducidas; pero, no se ha encontrado una investigación que consolide los datos sobre las mismas. La investigación tuvo como objetivo preparar una revisión sistemática sobre peces introducidos y potencialmente invasores en la costa norte peruana. Siguiendo las pautas de Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) del 2020, se obtuvieron 2665 documentos de Scopus, WoS, ScienceDirect, SciELO, Pubmed y Google Académico, Tras eliminar documentos duplicados y aplicar los criterios de inclusión y exclusión, se seleccionaron seis documentos. Se añadieron ocho documentos obtenidos de otras fuentes. Se reportaron 12 especies introducidas: carpa (Cyprinus carpio), gambusia (Gambusia affinis), guppy (Poecilia reticulata), pez cola de espada (Xiphophorus hellerii), mojarra (Coptodon rendalli), tilapia azul (Oreochromis aureus), tilapia mosámbica (Oreochromis mossambicus), tilapia nilótica (Oreochromis niloticus), wami tilapia (Oreochromis urolepis), cobia (Rachycentron canadum), trucha arcoíris (Oncorhynchus mykiss) y carachama (Hypostomus sp.). De estas, cinco especies fueron cíclidos y tres poecílidos; once especies se encontraron en agua dulce, cinco en manglares y dos en el mar. Tumbes registró el mayor número de cuerpos de agua con especies introducidas, Piura registró la mayor cantidad de especies (ocho), mientras que en Lambayeque se reportó solo una especie en un cuerpo de agua. Siete especies: carpa, gambusia, guppy, tilapias (azul, mosámbica y nilótica) y trucha arcoíris tienen alto potencial invasor, pues se encuentran entre las 100 peores especies invasoras de Europa o del mundo. Los documentos evaluados solo han reportado la presencia de especies introducidas, sin profundizar en el impacto que han tenido en los ecosistemas; por lo que, sería recomendable realizar investigaciones en esa dirección.

Abstract: This study has examined the design proposal for a support structure for a rainwater storage tank, utilizing CAD/CAE software with computational numerical analysis. These tools predict how elements will behave under specific conditions without physical construction. The necessity arises from the importance of developing the entire rainwater harvesting system to offer a sustainable water supply alternative. To this end, a storage capacity of 500 liters was determined based on locally available plastic tanks, considering the dimensions and weight the structure needs to support. 3D modeling utilized a 50 mm (2 in) square steel pipe discretized through meshing. Validation of this process achieved a skewness of 0.2401 with 414 651 elements and 601 334 nodes, defining the corresponding initial and boundary conditions. Von Mises stress measured 189.5 MPa, below the yield limit for structural steel, with structural element deformation not exceeding 0.83 mm. Design validation was accomplished through safety factor analysis, yielding a value of 1.746, closely aligning with recommended values for support structures.

Resumen: Esta investigación ha evaluado la viabilidad de un diseño para una estructura de soporte destinada a un tanque de almacenamiento de agua pluvial. Se utilizó software CAD/CAE para llevar a cabo un análisis numérico computacional debido a que estas herramientas permiten predecir comportamientos de elementos sometidos a condiciones específicas, sin necesidad de construcción. La necesidad de este diseño surge de la importancia de desarrollar un sistema integral para la captación de agua de lluvia, como una alternativa sostenible para el suministro de agua. Se estableció una capacidad de almacenamiento de 500 litros, considerando los tanques plásticos disponibles en el mercado local, para determinar las dimensiones y la carga que la estructura debe soportar. El modelado tridimensional se realizó utilizando una tubería cuadrada de acero estructural de 50 mm (2 plg), la cual fue discretizada mediante un mallado. Este proceso se validó alcanzando skewness de 0.2401, con un total de 414 651 elementos y 601 334 nodos, y se definieron las condiciones iniciales y de contorno correspondientes. El esfuerzo de Von Mises obtenido fue de 189.5 MPa, lo cual está por debajo del límite de fluencia para el acero estructural. Además, la deformación en los elementos estructurales no superó los 0.83 mm. El diseño se validó mediante un análisis del factor de seguridad, el cual fue de 1.746, aproximándose al valor recomendado para estructuras de soporte.

Abstract This study investigates the thermal behavior of three lithium-ion battery configurations under thermal runaway conditions, focusing on cooling systems based on air, water, and phase change materials (PCM). The analysis was conducted using sixteen cylindrical 18650 cells, each with a capacity of 2.15 Ah. The battery arrangements include Geometry 1, characterized by an irregular rhomboid shape, and Geometry 2, which adopts an irregular octagonal shape. Numerical simulations were carried out using Computational Fluid Dynamics (CFD) tools in ANSYS Fluent, employing a thermal abuse model rooted in a multidimensional, multiscale approach, and incorporating the empirical Newman-Tiedemann-Gauthier-Kim (NTGK) model. Transient simulations were performed under forced and natural convection scenarios to capture dynamic thermal behavior. The findings reveal that natural air cooling fails to prevent thermal runaway under the studied conditions. In contrast, water and PCM-based cooling systems effectively mitigate thermal runaway risks. Furthermore, forced convection with air and water significantly enhances thermal management and successfully prevents thermal runaway.

Resumen En este estudio se evalúa el comportamiento térmico ante condiciones de fuga térmica de tres arreglos de celdas de iones de litio con distintos sistemas de enfriamiento: aire, agua y material de cambio de fase (PCM). Se utilizaron 16 celdas cilíndricas de tipo 18650 con una capacidad de 2.15 Ah. La geometría 1 tiene una forma de rombo irregular, mientras que las geometrías 2 y 3 tienen una forma de un octágono irregular. Se implementaron simulaciones numéricas CFD empleando el software ANSYS Fluent mediante la aplicación del modelo de abuso térmico basado en un enfoque multidimensional multiescala y el modelo empírico NTGK. Se ejecutaron simulaciones transientes considerando convección forzada y natural. Los resultados muestran que, para las condiciones dadas en el estudio, el enfriamiento natural por aire no previene la fuga térmica, mientras que el agua y PCM sí la previenen, al igual que la convección forzada con aire y agua.

Abstract (Introduction): In the removal of chromium (VI) from tannery wastewater, physicochemical methods are the most used. However, these require high operating costs, and worse still, generate secondary pollutants that again require complementary treatments for their elimination. Given this, the applicability of vegetable organic biomass (VOB) emerges as an environmental alternative based on: the simplicity of its obtaining, the reduction as waste, it does not generate secondary pollutants and, above all, it removes chromium (VI). (Objective): Use VOB waste in an aerobic sequential biological reactor (SBR) for the removal of chromium (VI) in the treatment of tannery wastewater. (Methodology): 3 aerobic SBR systems were implemented; 2 controls (SBR1 and SBR2) and 1 study subject (SBR+VOB). Each system was fed with tannery wastewater (18 L) and connected to an aeration mechanism (12.7 L/min). The bacterial inoculum, a fundamental part of an SBR system, was gained from the selective culture of chromium (VI) reducing bacteria (RBCrVI) taken from the wastewater under study, and integrated into SBR2 and SBR+VOB at 0.6 g/L. The VOB was obtained from Stenotaphrum secundatum residues, fragmented, sieved, sterilized and integrated into the SBR+VOB at 1.5 g/L. (Results): The SBR+VOB system achieved the highest percentage of chromium (VI) removal (93 %), followed by SBR2 (80.1 %), and finally SBR1 (2.8 %). With respect to COD and TSS, the statistical test (Tukey) showed that there was no significant difference between the system under study and the controls, recording COD removal percentages ranging from 87.8 % to 88.4 %, and TSS ranging from 63.8 % to 69.2 %. (Conclusions): The viability of using VOB waste to remove chromium (VI) in the treatment of tannery wastewater has been evidenced. The results of this research create a promising panorama to mitigate the effects derived from inadequate management of tannery wastewater and organic solid waste.

Resumen (Introducción): En la remoción de cromo (VI) de aguas residuales de curtiembre, los métodos fisicoquímicos son los más empleados. Sin embargo, estos demandan altos costos operativos y, peor aún, generan contaminantes secundarios que nuevamente requieren tratamientos complementarios para su eliminación. Ante ello, la aplicabilidad de la biomasa orgánica vegetal (BOV) emerge como una alternativa ambiental sobre la base de: la simplicidad de su obtención, la disminución como residuo, no genera contaminantes secundarios y, sobre todo, de remover cromo (VI). (Objetivo): Usar residuos de BOV en un reactor biológico secuencial (RBS) aerobio, para la remoción de cromo (VI) en el tratamiento de agua residual de curtiembre. (Metodología): Se implementaron 3 sistemas RBS aerobios; 2 controles (RBS1 y RBS2) y 1 materia de estudio (RBS+BOV). Cada sistema fue alimentado con agua residual de curtiembre (18 L) y conectado a un mecanismo de aireación (12.7 L/ min). El inóculo bacteriano, parte fundamental de un sistema RBS, se obtuvo a partir del cultivo selectivo de bacterias reductoras de cromo (VI) (BRCrVI), tomadas del agua residual en estudio e integradas al RBS2 y RBS+BOV a 0.6 g/L. La BOV se obtuvo de residuos de Stenotaphrum secundatum, fragmentado, tamizado, esterilizado e integrado al RBS+BOV a 1.5 g/L. (Resultados): El sistema SRB+BOV alcanzó el mayor porcentaje de remoción de cromo (VI) (93 %), seguido por SBR2 (80.1 %) y, por último, de RBS1 (2.8 %). Con respecto a la DQO y SST, la prueba estadística (Tukey) arrojó que no había diferencia significativa entre el sistema en estudio y los controles, por lo que registró porcentajes de remoción de DQO que van de 87.8 % a 88.4 % y SST que van de 63.8 % a 69.2 %. (Conclusiones): Se ha evidenciado la viabilidad del aprovechamiento de residuos de BOV para remover cromo (VI) en el tratamiento de agua residual de curtiembre. Los resultados de la presente investigación crean un panorama prometedor para mitigar los efectos derivados de la inadecuada gestión de las aguas residuales de curtiembre y de los residuos sólidos orgánicos.

Resumo A reestruturação produtiva das metrópoles ocidentais, nas últimas décadas do século XX, exigiu dos governos nacionais e locais o debate e a elaboração de novos instrumentos urbanísticos voltados à reconversão física e funcional dos espaços então ocupados pela atividade industrial. Este artigo examina os casos do projeto urbano de King’s Cross, em Londres, e da Operação Urbana Água Branca, em São Paulo, ambos pautados na parceria entre poder público e iniciativa privada, especialmente por meio da negociação de ativos urbanos. Constatamos que no caso internacional, embora se observem elementos de exclusão, o processo projetual mirou soluções integradas de requalificação socioambiental. No caso paulistano, o processo de implementação foi caracterizado pela prevalência da modelagem regulatória do espaço em detrimento do projeto urbano. ocidentais XX industrial Kings King s Cross Londres Branca Paulo privada urbanos internacional exclusão socioambiental paulistano

Abstract The production restructuring of Western metropolises in the last decades of the 20th century required national and local governments to debate and develop new urban planning instruments aimed at the physical and functional reconversion of spaces previously occupied by industrial activities. This article examines the cases of the King's Cross urban project in London and the Água Branca Urban Operation in São Paulo, both based on partnerships between the public sector and private initiative, particularly through the negotiation of urban assets. We found that in the international case, although elements of exclusion were observed, the design process aimed at integrated solutions for socio-environmental requalification. In the São Paulo case, the implementation process was characterized by the regulatory modeling of the space to the detriment of urban design. th activities Kings King s initiative assets case observed socioenvironmental socio environmental requalification

Abstract — The hydrocarbons that contaminate water are difficult to remove, among other things, due to their hydrophobic nature. A surfactant is one way to facilitate contact between the treatment agents. This research prepared a biological surfactant from whey fermentation through Streptococcus thermophilus bacteria. To optimize its production, a complete factorial design was carried out, varying the factors temperature (38, 40, and 42 °C) and time (24, 48, and 72 hours), and the response variable is the amount of surfactant produced. It was found that the highest performance was obtained at 40ºC and 48 hours. The biosurfactant was characterized to determine hemolytic activity, Parafilm, oil dispersion, emulsification index (63.64 %), and surface tension (52.7 mN/m). The ecotoxicity test with Daphnia magna confirmed that the biosurfactant is environmentally friendly. Finally, a bioremediation process was applied during the 45 days when more than 50 % engine oil removal was achieved.

Resumen — Los hidrocarburos que contaminan el agua son difíciles de remover entre otras cosas por su naturaleza hidrofóbica. Una forma de facilitar el contacto entre el agente del tratamiento es usando un surfactante. En esta investigación se preparó un surfactante biológico a partir de la fermentación de lactosuero a través de las bacterias Streptococcus thermophilus. Para optimizar su producción se realizó un diseño factorial completo variando los factores la temperatura (38, 40 y 42 °C) y el tiempo (24, 48 y 72 horas) y siendo la variable respuesta la cantidad de surfactante producido. Se encontró que el mayor rendimiento se obtuvo a 40 ºC y 48 horas. Se caracterizó el biosurfactante para determinar actividad hemolítica, Parafilm, dispersión del aceite, índice de emulsificación (63.64 %) y tensión superficial (52.7 mN/m). La prueba de ecotoxicidad con Daphnia magna corroboró que el biosurfactantes es amigable con el ambiente. Finalmente, aplicando un proceso de biorremediación durante los 45 días donde se alcanzó más del 50 % de remoción de aceite de motor.

RESUMEN Este trabajo presenta una investigación acerca de la importancia del uso de Controversias SocioCientíficas (CSC) en la formación del profesorado a partir de una temática de interés actual que engloba la educación ambiental y alimentaria. Por ello, se plantea una secuencia didáctica (SD) sobre la problemática ambiental de arsénico (As) en agua y se platean dos CSC: 1) los límites legales de As en agua y 2) la contaminación del agua con As a partir de la urbanización en humedales. La SD fue aplicada a docentes de una capacitación de actualización sobre Ambiente, Desarrollo y Sociedad del último año de la escuela secundaria. El objetivo es conocer como el uso de CSC permite incorporar aspectos de naturaleza de la ciencia, desarrollar el pensamiento crítico, y trabajar temas motivacionales y de interés actuales. Los resultados obtenidos, mediante técnicas cualitativas y cuantitativas validadas, muestran un cambio en la concepción del profesorado sobre dichos ejes.

RESUMO Este trabalho apresenta uma investigação sobre a importância da utilização de Controvérsias Sociocientíficas (CSC) na formação de professores a partir de um tema de interesse atual que abrange a educação ambiental e alimentar. Por esse motivo, é proposta uma sequência didática (SD) sobre os problemas ambientais do arsénico (As) na água, colocando duas CSCs: 1) os limites legais do As na água e 2) a contaminação da água com As proveniente da urbanização em zonas húmidas. A SD foi aplicada a professores de uma formação contínua em Ambiente, Desenvolvimento e Sociedade do último ano do ensino secundário. O objetivo é saber como a utilização da CSC nos permite incorporar aspetos da natureza da ciência, desenvolver o pensamento crítico e trabalhar temas de interesse motivacionais e atuais. Os resultados obtidos, com recurso a técnicas qualitativas e quantitativas validadas, mostram uma mudança na conceção dos professores sobre estes temas.

ABSTRACT This paper presents an investigation about the importance of the use of Socio-Scientific Controversies (SSC) in teacher training based on a topic of current interest that encompasses environmental and food education. For this reason, a didactic sequence (DS) is proposed on the environmental problems of arsenic (As) in water and two SSIs are raised: 1) the legal limits of As in water and 2) the contamination of water with As as a result of the urbanization of wetlands. The DS was applied to teachers of a continuous training on Environment, Development and Society in the last year of secondary school. The objective is to know how the use of SSC allows us to incorporate aspects of the nature of science, develop critical thinking and work on motivational and current topics of interest. The results obtained, through validated qualitative and quantitative techniques, show a change in the teachers' conception of these issues.

Abstract: The present study aims to analyze the covariational reasoning of students when solving tasks that involve functional relationships by conducting GeoGebra simulations of filling containers. The notions of mental action and levels of covariational reasoning are considered as a theoretical construct, and the case study as a research method. As a result, different strategies are identified to graphically represent the relationship between the height of water inside a container that changes shape, and the volume of water that enters it constantly. The strategies are related to student covariational reasoning and include using areas of geometric figures to relate both variables and construct a finite set of points in the plane to graphically represent functional relationships. In conclusion, the simulations performed with GeoGebra allow students to visualize how simultaneous changes occur between two variables, and thus recognize functional relationships as a dynamic covariation of variables.

Resumen: El presente estudio tiene por objetivo analizar el razonamiento covariacional de un estudiante al resolver tareas que involucran relaciones funcionales al simular con GeoGebra el llenado de recipientes. Se consideran las nociones de acción mental y de niveles de razonamiento covariacional como constructo teórico, y el estudio de caso como método de investigación. Como resultado, se identifican diferentes estrategias para representar gráficamente la relación entre la altura del agua dentro de un recipiente que cambia de forma, y el volumen de agua que ingresa de manera constante. Las estrategias guardan relación con el razonamiento covariacional del estudiante e incluyen utilizar áreas de figuras geométricas para relacionar ambas variables y construir un conjunto finito de puntos en el plano para representar gráficamente las relaciones funcionales. En conclusión, las simulaciones realizadas con GeoGebra posibilitan al estudiante una visualización de cómo se dan los cambios simultáneos entre dos variables, y con ello reconocer las relaciones funcionales como una covariación dinámica de variables.

Abstract This study aimed to understand the impact of municipal basic sanitation policies and plans on the rate of access to drinking water and sewage services. For this, data were collected from the 853 municipalities of Minas Gerais regarding the provision of sanitation, as well as socioeconomic, quality of life and demographic indicators, treated with the t-test techniques for differences between means and Propensity Score Matching. The results revealed the need for greater sanitation planning in the state since a significant portion of municipalities do not have formal planning instruments for the sector. Furthermore, it was found that sanitation policies and plans had a positive impact on the rates of access to sanitation, both total and urban. However, regarding water supply, the data did not reveal a statistically significant positive impact. Therefore, the results shed light on the effectiveness of planning instruments for this category of services, revealing their contribution to expanding access to sanitation.

Resumo Este estudo objetivou compreender o impacto das políticas e planos municipais de saneamento básico sobre a taxa de acesso aos serviços de água potável e esgotamento sanitário. Para isso, foram coletados dados dos 853 municípios de Minas Gerais no que se refere ao provimento do saneamento, bem como indicadores socioeconômicos, de qualidade de vida e demográficos, tratados com as técnicas de teste t de diferenças entre médias e Propensity Score Matching. Os resultados revelaram a necessidade de maior planejamento do saneamento no estado, uma vez que uma significativa parcela dos municípios não dispõem de instrumentos formais de planejamento do setor. Ademais, verificou-se que as políticas e planos de saneamento impactaram positivamente nos índices de acesso ao esgotamento sanitário, tanto totais quanto urbanos. Porém, no que refere ao abastecimento de água, os dados não revelaram impacto positivo estatisticamente significativo. Portanto, os resultados jogam luz sobre a efetividade dos instrumentos de planejamento sobre essa categoria de serviços, revelando sua contribuição para a ampliação do acesso ao esgotamento sanitário.

Resumen Este estudio tuvo como objetivo comprender el impacto de las políticas y planes municipales de saneamiento básico en la tasa de acceso a los servicios de agua potable y alcantarillado. Para ello, se recogieron datos de los 853 municipios de Minas Gerais, Brasil, sobre la provisión de saneamiento, así como indicadores socioeconómicos de calidad de vida y demográficos tratados con las técnicas de prueba t para diferencias entre medias y emparejamiento por puntuación de propensión (PSM). Los resultados revelaron la necesidad de una mayor planificación del saneamiento en el estado, ya que una parte importante de los municipios no cuentan con instrumentos formales de planificación para el sector. Además, se encontró que las políticas y planes de saneamiento tuvieron un impacto positivo en las tasas de acceso al saneamiento, tanto total como urbano. Sin embargo, en lo que respecta al suministro de agua, los datos no revelaron un impacto positivo estadísticamente significativo. Por lo tanto, los resultados arrojan luz sobre la efectividad de los instrumentos de planificación para esta categoría de servicios, revelando su contribución a la ampliación del acceso al saneamiento.