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The COVID-19 pandemic made robot manufacturers explore the idea of combining mobile robotics with UV-C light to automate the disinfection processes. But performing this process in an optimum way introduces some challenges: on the one hand, it is necessary to guarantee that all surfaces receive the radiation level to ensure the disinfection; at the same time, it is necessary to minimize the radiation dose to avoid the damage of the environment. In this work, both challenges are addressed with the design of a complete coverage path planning (CCPP) algorithm. To do it, a novel architecture that combines the glasius bio-inspired neural network (GBNN), a motion strategy, an UV-C estimator, a speed controller, and a pure pursuit controller have been designed. One of the main issues in CCPP is the deadlocks. In this application they may cause a loss of the operation, lack of regularity and high peaks in the radiation dose map, and in the worst case, they can make the robot to get stuck and not complete the disinfection process. To tackle this problem, in this work we propose a preventive deadlock processing algorithm (PDPA) and an escape route generator algorithm (ERGA). Simulation results show how the application of PDPA and the ERGA allow to complete complex maps in an efficient way where the application of GBNN is not enough. Indeed, a 58% more of covered surface is observed. Furthermore, two different motion strategies have been compared: boustrophedon and spiral motion, to check its influence on the performance of the robot navigation.
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SARS-CoV-2 has emerged as a human pathogen, causing clinical signs, from fever to pneumonia-COVID-19-but may remain mild or asymptomatic. To understand the continuing spread of the virus, to detect those who are and were infected, and to follow the immune response longitudinally, reliable and robust assays for SARS-CoV-2 detection and immunological monitoring are needed. We quantified IgM, IgG, and IgA antibodies recognizing the SARS-CoV-2 receptor-binding domain (RBD) or the Spike (S) protein over a period of 6 months following COVID-19 onset. We report the detailed setup to monitor the humoral immune response from over 300 COVID-19 hospital patients and healthcare workers, 2500 University staff, and 198 post-COVID-19 volunteers. Anti-SARS-CoV-2 antibody responses follow a classic pattern with a rapid increase within the first three weeks after symptoms. Although titres reduce subsequently, the ability to detect anti-SARS-CoV-2 IgG antibodies remained robust with confirmed neutralization activity for up to 6 months in a large proportion of previously virus-positive screened subjects. Our work provides detailed information for the assays used, facilitating further and longitudinal analysis of protective immunity to SARS-CoV-2. Importantly, it highlights a continued level of circulating neutralising antibodies in most people with confirmed SARS-CoV-2.
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Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/inmunología , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto , Anciano , Anciano de 80 o más Años , COVID-19/epidemiología , Femenino , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos , Factores de TiempoRESUMEN
The effect of the fungicide pyrimethanil (0.7 mg L(−1)) on biofilm development and alder leaf litter decomposition in aquatic ecosystems was assessed in outdoor lentic mesocosms immediately and 274 days after pyrimethanil application. Pyrimethanil decreased ergosterol concentrations (an indicator of fungal biomass) and the abundance and richness of the macroinvertebrate community associated with decomposing leaves. However, because neither fungi nor macroinvertebrates were main factors contributing to decomposition in this particular system, organic matter processing rates were not affected. After 274 days, pyrimethanil concentration in the water column was ≤0.004 mg L(−1) but richness, biomass and composition of the invertebrate community associated with decomposing leaf-litter still showed the effect. The comparison of ergosterol (a molecule existing on both algae and fungal cell membranes), with chlorophyll (an indicator of algal biomass) associated with biofilm suggests that pyrimethanil may decrease fungal biomass and alter the relative abundance of algae and fungi on biofilm developing in control- and treated-mesocosms.
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Fenómenos Fisiológicos Bacterianos/efectos de los fármacos , Biopelículas/efectos de los fármacos , Fungicidas Industriales/metabolismo , Compuestos Orgánicos/metabolismo , Pirimidinas/metabolismo , Contaminantes Químicos del Agua/metabolismo , Relación Dosis-Respuesta a Droga , Estanques/química , Estanques/microbiología , Portugal , Estaciones del AñoRESUMEN
There is growing concern that modifications to the global environment such as ocean acidification and increased ultraviolet radiation may interact with anthropogenic pollutants to adversely affect the future marine environment. Despite this, little is known about the nature of the potential risks posed by such interactions. Here, we performed a multifactorial microcosm experiment to assess the impact of ocean acidification, ultraviolet B (UV-B) radiation and oil hydrocarbon contamination on sediment chemistry, the microbial community (composition and function) and biochemical marker response of selected indicator species. We found that increased ocean acidification and oil contamination in the absence of UV-B will significantly alter bacterial composition by, among other things, greatly reducing the relative abundance of Desulfobacterales, known to be important oil hydrocarbon degraders. Along with changes in bacterial composition, we identified concomitant shifts in the composition of oil hydrocarbons in the sediment and an increase in oxidative stress effects on our indicator species. Interestingly, our study identifies UV-B as a critical component in the interaction between these factors, as its presence alleviates harmful effects caused by the combination of reduced pH and oil pollution. The model system used here shows that the interactive effect of reduced pH and oil contamination can adversely affect the structure and functioning of sediment benthic communities, with the potential to exacerbate the toxicity of oil hydrocarbons in marine ecosystems.
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Cambio Climático , Estuarios , Sedimentos Geológicos/microbiología , Microbiota/fisiología , Modelos Biológicos , Contaminación por Petróleo/efectos adversos , Secuencia de Bases , Cartilla de ADN/genética , Deltaproteobacteria/metabolismo , Deltaproteobacteria/efectos de la radiación , Hidrocarburos/análisis , Concentración de Iones de Hidrógeno , Microbiota/efectos de los fármacos , Datos de Secuencia Molecular , Portugal , Análisis de Secuencia de ADN , Rayos UltravioletaRESUMEN
Smart applications of the Internet of Things are improving the performance of buildings, reducing energy demand. Local and smart networks, soft computing methodologies, machine intelligence algorithms and pervasive sensors are some of the basics of energy optimization strategies developed for the benefit of environmental sustainability and user comfort. This work presents a distributed sensor-processor-communication decision-making architecture to improve the acquisition, storage and transfer of thermal energy in buildings. The developed system is implemented in a near Zero-Energy Building (nZEB) prototype equipped with a built-in thermal solar collector, where optical properties are analysed; a low enthalpy geothermal accumulation system, segmented in different temperature zones; and an envelope that includes a dynamic thermal barrier. An intelligent control of this dynamic thermal barrier is applied to reduce the thermal energy demand (heating and cooling) caused by daily and seasonal weather variations. Simulations and experimental results are presented to highlight the nZEB thermal energy reduction.
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In situ assays based on feeding depression have been proposed as sublethal assays able to assess immediate contaminant effects on key ecosystem functions, long before effects on life-history traits can be detected. The in situ peculiarities provide more realistic exposure scenarios than laboratory-controlled conditions, which is particularly relevant for estuarine ecosystems where environmental conditions are highly variable. In this context, we developed a short-term cost-effective in situ assay based on the postexposure feeding of the estuarine species, Cyathura carinata, through the following steps: i) develop a methodology to quantify feeding under laboratory conditions; ii) quantify the sensitivity of the postexposure feeding response under laboratory conditions; iii) deploy the in situ assay at various field sites covering different environmental variables in a reference estuary and degrees of contamination in a contaminated estuary to, respectively, derive a model to predict postexposure feeding rates across sites varying in environmental variables and evaluate the potential of this in situ tool to assess sediment contamination in estuaries. A quantity of 100 defrosted nauplii of Artemia franciscana per isopod given during a short period of 30 min in darkness was adequate to allow estimating precise postexposure feeding rates. Laboratory toxicity tests showed the high sensitivity of postexposure feeding to Cd as a sublethal endpoint for C. carinata (7-fold lower than the corresponding 48-h LC50). However, this species appears to be able to face high concentrations of non-essential metals as Cd, with 96-h LC50 values (37 mg Cd/L) higher than values reported for other isopods, and among the highest concentrations reported for saltwater invertebrates. Results of in situ deployments at reference sites indicated that sediment with size fraction between 63-125 µm (very fine sand) influences feeding rates. The in situ assay across contaminated sites was able to discriminate between unpolluted and polluted estuaries, and also to detect degrees of toxicity among sampling sites within an estuary, after statistically adjusting feeding rates on the basis of the proportion of the sediment very fine sand influencing baseline feeding rates. The in situ postexposure feeding assay with C. carinata was found to be, therefore, a potential useful cost-effective tool for estuarine sediment toxicity assessments.
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Conducta Alimentaria/efectos de los fármacos , Sedimentos Geológicos/química , Isópodos/fisiología , Contaminantes Químicos del Agua/toxicidad , Animales , Cadmio/toxicidad , EstuariosRESUMEN
Contaminants can behave as toxicants, when toxic effects are observed in organisms, as well as habitat disturbers and fragmentors, by triggering avoidance responses and generating less- or uninhabited zones. Drift by stream insects has long been considered a mechanism to avoid contamination by moving to most favorable habitats. Given that exploration and transportation of crude oil represent a threat for surrounding ecosystems, the key goal of the present study was to assess the ability of autochthonous groups of aquatic insects from the Ecuadorian paramo streams to avoid by drift different concentrations of polycyclic aromatic hydrocarbons (PAH) contained in the soluble fraction of locally transported crude oil. In the laboratory, different groups of insects were exposed to PAH for 12h. Three different assays, which varied in taxa and origin of the organisms, concentrations of PAH (0.6-38.8µgL(-1)), and environment settings (different levels of refuge and flow) were performed. For Anomalocosmoecus palugillensis (Limnephilidae), drift was a major cause of population decline in low concentration treatments but at higher concentrations mortality dominated. PAH was highly lethal, even at lower concentrations, for Chironomidae, Grypopterygidae (Claudioperla sp.) and Hydrobiosidae (Atopsyche sp.), and, therefore, no conclusion about drift can be drawn for these insects. Contamination by PAH showed to be a threat for benthic aquatic insects from Ecuadorian paramo streams as it can cause a population decline due to avoidance by drift and mortality.
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Ecosistema , Insectos/efectos de los fármacos , Petróleo/toxicidad , Ríos , Contaminantes Químicos del Agua/toxicidad , Animales , Chironomidae/efectos de los fármacos , Monitoreo del Ambiente , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , América del Sur , Movimientos del AguaRESUMEN
The present study aimed to assess the environmental fate of the insecticide and nematicide ethoprophos in the soil-water interface following the pesticide application in simulated maize and potato crops under Mediterranean agricultural conditions, particularly of irrigation. Focus was given to the soil-water transfer pathways (leaching and runoff), to the pesticide transport in soil between pesticide application (crop row) and non-application areas (between crop rows), as well as to toxic effects of the various matrices on terrestrial and aquatic biota. A semi-field methodology mimicking a "worst-case" ethoprophos application (twice the recommended dosage for maize and potato crops: 100% concentration v/v) in agricultural field situations was used, in order to mimic a possible misuse by the farmer under realistic conditions. A rainfall was simulated under a slope of 20° for both crop-based scenarios. Soil and water samples were collected for the analysis of pesticide residues. Ecotoxicity of soil and aquatic samples was assessed by performing lethal and sublethal bioassays with organisms from different trophic levels: the collembolan Folsomia candida, the earthworm Eisenia andrei and the cladoceran Daphnia magna. Although the majority of ethoprophos sorbed to the soil application area, pesticide concentrations were detected in all water matrices illustrating pesticide transfer pathways of water contamination between environmental compartments. Leaching to groundwater proved to be an important transfer pathway of ethoprophos under both crop-based scenarios, as it resulted in high pesticide concentration in leachates from Maize (130µgL(-1)) and Potato (630µgL(-1)) crop scenarios, respectively. Ethoprophos application at the Potato crop scenario caused more toxic effects on terrestrial and aquatic biota than at the Maize scenario at the recommended dosage and lower concentrations. In both crop-based scenarios, ethoprophos moved with the irrigation water flow to the soil between the crop rows where no pesticide was applied, causing toxic effects on terrestrial organisms. The two simulated agricultural crop-based scenarios had the merit to illustrate the importance of transfer pathways of pesticides from soil to groundwater through leaching and from crop rows to the surrounding soil areas in a soil-water interface environment, which is representative for irrigated agricultural crops under Mediterranean conditions.
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Agricultura , Biota/efectos de los fármacos , Compuestos Organotiofosforados/metabolismo , Compuestos Organotiofosforados/toxicidad , Contaminantes del Suelo/toxicidad , Suelo/química , Agua/química , Aire/análisis , Animales , Artrópodos/efectos de los fármacos , Productos Agrícolas , Daphnia/efectos de los fármacos , Concentración 50 Inhibidora , Región Mediterránea , Oligoquetos/efectos de los fármacos , Organotiofosfatos , Reproducción/efectos de los fármacos , Contaminantes del Suelo/análisis , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidadRESUMEN
Several oil spills due to ruptures in the pipeline oil systems have occurred at the Andean paramo. A sample of this crude oil was mixed with water from a nearby Andean lagoon and the toxicity of the soluble fraction was assessed through lethal and avoidance assays with a locally occurring copepod (Boeckella occidentalis intermedia). The integration of mortality and avoidance aimed at predicting the immediate decline of copepod populations facing an oil leakage. The 24-h median lethal PAH concentration was 42.7 (26.4-91.6) µg L(-1). In the 12-h avoidance assay, 30% avoidance was recorded at the highest PAH concentration (19.4 µg L(-1)). The mortality at this PAH concentration would be of 25% and, thus, the population immediate decline would be of 55%. The inclusion of non-forced exposure testing with the quantification of the avoidance response in environmental risk assessments is, therefore, supported due to underestimation of the lethal assays.
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Copépodos/fisiología , Contaminación por Petróleo , Petróleo/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Copépodos/efectos de los fármacos , Dosificación Letal MedianaRESUMEN
Phosphatidylethanolamine (PE) and phosphatidylserine (PS), along with phosphatidylcholine (PC), are key phospholipids (PL) in cell membranes and lipoproteins, prone to oxidative modifications. Their oxidized forms, OxPE and OxPS, play significant roles in inflammation and immune response. This review explores their structural oxidative changes under non-enzymatic conditions and their roles in physiological and pathological contexts, influencing inflammation, and immunity. Specific oxidations of PE and PS significantly alter their physicochemical properties, leading to enhanced biological functions, reduced activity, or inactivation. OxPE may show pro-inflammatory actions, similar to well-documented OxPC, while the OxPS pro-inflammatory effects are less noted. However, OxPS and OxPE have also shown an antagonistic effect against lipopolysaccharides (LPS), suggesting a protective role against exacerbated immune responses, similar to OxPC. Further research is needed to deepen our understanding of these less-studied OxPL classes. The role of OxPE and OxPS in disease pathogenesis remains largely unexplored, with limited studies linking them to Alzheimer's disease, diabetes, rheumatoid arthritis, traumatic brain injury, and skin inflammation. These findings highlight the potential of OxPE and OxPS as biomarkers for disease diagnosis, monitoring, and therapeutic targeting.
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Inflamación , Oxidación-Reducción , Fosfatidiletanolaminas , Fosfatidilserinas , Humanos , Fosfatidiletanolaminas/metabolismo , Inflamación/metabolismo , Fosfatidilserinas/metabolismo , AnimalesRESUMEN
Habitat selection by aquatic organisms is dependent on the availability of adequate conditions to support life and the benefits that the habitat provides. Contaminated environments tend to be less attractive to organisms because reduced habitat quality leads to increased maintenance costs. Consequently, reduced colonization of such disturbed habitats is an expected response. However, colonization has been understudied as an ecotoxicological test endpoint, despite its proven ability to assess habitat selection by populations across various taxa. The aim of the present study was to investigate whether previous exposure to copper could alter the colonization behavior of the freshwater prawn Macrobrachium rosenbergii along a non-forced exposure gradient of interconnected copper-contaminated habitats (0 to 500 µg/L) due to physiological and behavioral impairments. To assess this, post-larvae of M. rosenbergii were pre-exposed to 0, 50, 250 and 500 µg/L copper for a maximum period of 48 h. The physiological status and motility of the organisms after pre-exposure to copper were evaluated using behavioral endpoints (swimming activity by video tracking) and biochemical biomarkers (biotransformation, oxidative stress and neurotoxicity). The results indicated that pre-exposure to copper (at concentrations of 0, 50 and 500 µg/L) significantly influenced the median colonization concentration (CC50), which decreased from 270 µg/L to 109 µg/L. None of the assessed swimming parameters (speed, motility rate, exploration rate, and total distance) were affected by the pre-exposure to copper (0, 50 and 250 µg/L). Biochemically, cholinesterase levels were only affected in the prawn population exposed to 250 µg/L of copper. The present study provides a better understanding of the relevance of colonization as an ecotoxicological endpoint for assessing the spatial distribution of populations, including both new inhabitants and previously exposed organisms, in recovering habitats.
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Conducta Animal , Cobre , Ecosistema , Palaemonidae , Contaminantes Químicos del Agua , Animales , Palaemonidae/efectos de los fármacos , Palaemonidae/fisiología , Cobre/toxicidad , Contaminantes Químicos del Agua/toxicidad , Conducta Animal/efectos de los fármacos , Biomarcadores , Estrés Oxidativo/efectos de los fármacosRESUMEN
Species phenology - the timing of key life events - is being altered by ongoing climate changes with yet underappreciated consequences for ecosystem stability. While flowering is generally occurring earlier, we know much less about other key processes such as the time of fruit ripening, largely due to the lack of comprehensive long-term datasets. Here we provide information on the exact date and site where seeds of 4,462 taxa were collected for the Index Seminum (seed exchange catalogue) of the Botanic Garden of the University of Coimbra, between 1926 and 2013. Seeds were collected from spontaneous and cultivated individuals across Portugal, including both native and introduced taxa. The database consists of 127,747 curated records with information on the species, or infraspecific taxa (including authority), and the day and site where seeds were collected. All records are georeferenced and provided with a confidence interval for the collection site. Taxonomy was first curated manually by in-house botanists and then harmonized according to the GBIF backbone taxonomy.
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Frutas , Plantas , Cambio Climático , Ecosistema , Plantas/clasificación , Portugal , SemillasRESUMEN
Despite the growing concern over nanoplastics' (NPls) environmental impacts, their long-term effects on terrestrial organisms remain poorly understood. The main aim of this study was to assess how NPls exposure impacts both the parental (F1) and subsequent generations (F2 and F3) of the soil-dwelling species Folsomia candida. After a standard exposure (28 days), we conducted a multigenerational study along three generations (84 days), applying polystyrene nanoparticles (PS NPs; diameter of 44 nm) as representatives of NPls. Endpoints from biochemical to individual levels were assessed. The standard test: PS NPs (0.015 to 900 mg/kg) had no effect in F. candida survival or reproduction. The multigenerational test: PS NPs (1.5 and 300 mg/kg) induced no effects on F. candida survival and reproduction along the three generations (F1 to F3). PS NPs induced no effects in catalase, glutathione reductase, glutathione S-transferases, and acetylcholinesterase activities for the juveniles of the F1 to F3. Oxidative damage through lipid peroxidation was detected in the offspring of F1 but not in the juveniles of F2 and F3. Our findings underscore the importance of evaluating multigenerational effects to gain comprehensive insights into the contaminants long-term impact, particularly when organisms are continuously exposed, as is the case with NPls.
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The knowledge produced in temperate regions is still used today to evaluate environmental problems in the tropics, without taking into consideration environmental differences, such as local conditions, the sensitivity and ecology of species, and exposure routes of contaminants, essential for understanding and determining the fate and toxicity of chemicals. Considering that Environmental Risk Assessment (ERA) studies for tropical systems are scarce and need to be adjusted, the present study aims at contributing to the awareness and development of tropical ecotoxicology. The estuary of the Paraíba River in Northeast Brazil was selected as a model study-case, as it is a large estuary, subjected to a heavy human pressure due to the numerous social, economic and industrial activities. The present study describes the framework for the problem formulation phase of the ERA process; it first includes a detailed integration of the scientific information available on the study area, to then derive the conceptual model, and finally present the analysis plan for the tier 1 screening phase. The latter is designed to be fundamentally supported by the ecotoxicological line of evidence, to ascertain, without delay, where and why there are environmental problems (i.e., adverse biological effects); ecotoxicological tools developed in temperate climates will be optimized to assess water quality in a tropical system. In addition to its intrinsic value for protecting the study area, the results of the present study are expected to provide an important baseline for conducting ERA in similar tropical aquatic systems across the globe.
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Ecotoxicología , Contaminantes Químicos del Agua , Humanos , Estuarios , Ríos , Brasil , Medición de Riesgo/métodos , Contaminantes Químicos del Agua/toxicidad , Monitoreo del Ambiente/métodosRESUMEN
Over time multiple lines of research have been integrated as important components of evidence for assessing the ecological quality status of water bodies within the framework of Environmental Risk Assessment (ERA) approaches. One of the most used integrative approaches is the triad which combines, based on the weight-of-evidence, three lines of research, the chemical (to identify what is causing the effect), the ecological (to identify the effects at the ecosystem level) and the ecotoxicological (to ascertain the causes of ecological damage), with the agreement between the different lines of risk evidence increasing the confidence in the management decisions. Although the triad approach has proven greatly strategic in ERA processes, new assessment (and monitoring) integrative and effective tools are most welcome. In this regard, the present study is an appraisal on the boost that passive sampling, by allowing to increase information reliability, can give within each of the triad lines of evidence, for more integrative ERA frameworks. In parallel to this appraisal, examples of works that used passive samplers within the triad are presented providing support for the use of these devices in a complementary form to generate holistic information for ERA and ease the process of decision-making.
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Ecosistema , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Reproducibilidad de los Resultados , Medición de Riesgo , Ecotoxicología , Contaminantes Químicos del Agua/análisisRESUMEN
Industrial metal-rich sludge can improve soil properties, but it is potentially toxic to soils and adjacent aquatic systems. The soil-sludge-water interactions influence metals bioavailability over time, a phenomenon mostly regulated by the still debatable "sludge physical protection" or "sludge delayed release" hypotheses. The present study aimed to investigate: (1) whether sludge increases soil aggregate stability against slaking, (2) which hypothesis mostly regulates metal release from soils to water and (3) the ecotoxicity of the metals released during soil slaking for aquatic organisms. Under a realistic field scale, soils amended with an industrial sludge or spiked with equivalent metal solutions (of Cr, Cu, Ni, Zn) were collected over three months to test soil aggregate stability, the ecotoxicity of the slaking water and metal contents in soil and water. The "sludge physical protection" was verified for all metals, though for Cu the "sludge delayed release" hypothesis appears plausible after three months. Soil amendment with sludge did not lead to effects on the growth of the microalga Raphidocelis subcapitata, contrarily to the observed for the metal-spiked soil. Criteria regulating soils sludge-amendment management should thus include doses not hazardous to biota, and not only metal threshold levels.
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Metales Pesados , Contaminantes del Suelo , Suelo , Metales Pesados/toxicidad , Metales Pesados/análisis , Aguas del Alcantarillado , Agua , Contaminantes del Suelo/toxicidad , Contaminantes del Suelo/análisisRESUMEN
The impact of diazinon spraying in an agricultural tropical soil through the evaluation of both the habitat and retention functions of the soil system was never reported. To fill this gap, five times the recommended dose of a commercial diazinon formulation was sprayed in an agricultural area of Costa Rica, and dilution gradients of the sprayed soil were prepared in the laboratory. Avoidance and reproduction tests with soil organisms (Eisenia andrei, Enchytraeus crypticus and Folsomia candida) to evaluate losses in terrestrial habitat function, and growth and reproduction tests with aquatic organisms (Chlorella vulgaris and Daphnia magna, respectively) to evaluate the retention function of soil were performed. Results demonstrated that regarding habitat function, F. candida reproduction was the most sensitive endpoint (EC(50) = 0.288 mg a.i./kg), followed by avoidance behaviour of E. andrei (EC(20) = 1.75 mg a.i./kg). F. candida avoidance and the reproduction of E. andrei and E. crypticus were not affected by diazinon. The toxicity tests with aquatic organisms showed that the soil retention function was insufficient to prevent effects of diazinon either on microalgae growth (EC(50) ≤ 0.742 mg/L and EC(20) ≤ 0.223 mg/L) and on the reproduction of the cladoceran (EC(50) ≤ 0.00771 mg/L and EC(20) ≤ 0.00646 mg/L). Results suggested that diazinon exerted toxic effects even at the dilution corresponding to the recommended dose, fact which makes its misuse an issue of environmental concern. Furthermore, the present study highlighted the importance and complementary nature of the assessment of both habitat and retention functions to an ecological risk assessment in tropical systems.
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Artrópodos/efectos de los fármacos , Chlorella/efectos de los fármacos , Diazinón/toxicidad , Insecticidas/toxicidad , Oligoquetos/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Contaminantes Químicos del Agua/toxicidad , Agricultura , Animales , Artrópodos/crecimiento & desarrollo , Artrópodos/fisiología , Chlorella/crecimiento & desarrollo , Chlorella/fisiología , Costa Rica , Relación Dosis-Respuesta a Droga , Cromatografía de Gases y Espectrometría de Masas , Dosificación Letal Mediana , Actividad Motora , Oligoquetos/fisiología , ReproducciónRESUMEN
Water-sediment quality was assessed in an agricultural zone of a protected area within the Tagus River basin district (central Portugal) combining chemical analysis to 12 pesticide compounds and whole toxicity testing using the bacterium , the algae , the crustacean , and the midge . The herbicides alachlor, atrazine ethofumesate, metolachlor, terbuthylazine, the insecticides chlorfenvinphos and chlorpyrifos, and the metabolite 3,4-dichloroaniline were detected in surface water samples at four sites and in groundwater samples from six wells, during four sampling occasions. Measured concentrations were compared with parametric values for human consumption, groundwater quality standards, and environmental quality standards applicable to surface water established in European Union legislation. Most severe adverse effects were noted on the growth of and lethality of in nondiluted water samples. Taking into account the values calculated by the method of toxic unit summation for pesticide mixtures, it was not possible to link the pesticides found to the toxicity detected in the water samples. Conducting this study with chemical analyses and biotests provided a more comprehensive quality assessment and realistic picture of the environmental samples analyzed, although additional studies are needed to evaluate the performance of mixture models for predicting mixture toxicity. This study underlines the importance of chemical analysis and whole toxicity testing as tools for assessing the impact of human activity on the status of water, mainly in protected zones.
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Plaguicidas/análisis , Ríos , Contaminantes Químicos del Agua/análisis , Calidad del Agua , Aliivibrio fischeri , Animales , Organismos Acuáticos , Chironomidae , Daphnia , Sedimentos Geológicos/análisis , Agua Subterránea/análisis , Plaguicidas/toxicidad , Portugal , Medición de Riesgo , Pruebas de ToxicidadRESUMEN
Although they are highly suited for site-specific risk assessment, little attention has been given to in situ ecotoxicological experimentation in tropical regions. This study intended to assess the suitability of five freshwater cladocerans from Mexico for in situ experiments. Juveniles of Ceriodaphnia cornuta, Macrothrix triserialis group, Simocephalus vetulus, Diaphanosoma birgei, and Pseudosida cf. ramosa, from two populations, were used to perform seven day laboratory and in situ experiments. Pseudosida cf. ramosa was very sensitive to handling and was discarded from further evaluations. Ceriodaphnia cornuta reproduced significantly more neonates, with smaller coefficients of variation, than M. triserialis and S. vetulus. Also due to its worldwide distribution in the tropics, C. cornuta is suggested to be highly suitable for in situ experiments.
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Cladóceros/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Animales , Tamaño Corporal/efectos de los fármacos , Cladóceros/clasificación , Cladóceros/crecimiento & desarrollo , Cladóceros/metabolismo , Agua Dulce , México , Reproducción/efectos de los fármacos , Medición de Riesgo/métodos , Especificidad de la Especie , Análisis de Supervivencia , Pruebas de ToxicidadRESUMEN
The aim of this paper is to classify the land covered with oat crops, and the quantification of frost damage on oats, while plants are still in the flowering stage. The images are taken by a digital colour camera CCD-based sensor. Unsupervised classification methods are applied because the plants present different spectral signatures, depending on two main factors: illumination and the affected state. The colour space used in this application is CIELab, based on the decomposition of the colour in three channels, because it is the closest to human colour perception. The histogram of each channel is successively split into regions by thresholding. The best threshold to be applied is automatically obtained as a combination of three thresholding strategies: (a) Otsu's method, (b) Isodata algorithm, and (c) Fuzzy thresholding. The fusion of these automatic thresholding techniques and the design of the classification strategy are some of the main findings of the paper, which allows an estimation of the damages and a prediction of the oat production.