1,779 research outputs found

    Dataset of human interventions as anthropogenic perturbations on the Caribbean coast of Colombia

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    Human interventions on coastal areas are always causing environmental impact; however, most of the times inventories of those interventions are possibly not well structured, and surely without a specific standard. The raw data presented shows an exhaustive and systematic revision of satellite images on 1700 km of the Caribbean coast of Colombia, where 2743 human interventions were identified. These interventions are classified in 38 categories in order to assess their environmental impact at a regional scale. The filtered data shows the environmental impact obtained for each category and the values allotted to each of the four parameters used for this evaluation. Moreover, the data is filtered for each of the five environmental coastal units in which the Caribbean coast of Colombia is divided by national regulations. Finally, the filtered and processed data shows the analysis done to obtain the graphical results of a previously paper (An evaluation of human interventions in the anthropogenically disturbed Caribbean Coast of Colombia [1]). Therefore, this dataset comprises three spreadsheets (xlsx) and two geographical files (kmz), which are ready to be used for any researcher, decision maker, land planner or practitioner interested in making further analysis on environmental impact assessment in coastal areas. Additionally, the dataset is carefully organised for educational exercises in such a manner that professors or lecturers can repeat the same steps in this study area or in their own, from the inventory to the final results

    Evolutionary procedure based model to predict ground–level ozone concentrations

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    AbstractThis study aims to predict the next day hourly average ozone (O3) concentrations using threshold autoregressive (TAR) models in which the threshold value and the threshold variable are defined by genetic algorithms. The procedure is also able to generate models with statistically significant regression parameters. The performance of TAR models was then compared to the one obtained with autoregressive (AR) and artificial neural network (ANN) models. Different TAR models were generated, corresponding to different threshold variables and values. For the training period, ANN model presented better results than TAR and AR models. However, in the test period, AR and one of the TAR models achieved better predictions of O3 concentrations than the ANN model. The distinction between the applied models became greater when they were evaluated in the prediction of the extreme values, for which the TAR model presented the best performance. The performance with respect to extreme values is a useful implication for the protection of public health as this model can provide more reliable early warnings about high O3 concentration episodes

    Comparative approach for assessing the soil quality in an urban conservation unit

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    Received: August 16th, 2023 ; Accepted: October 30th, 2023 ; Published: November 6th, 2023 ; Correspondence: [email protected] study aimed to verify the quality of the soil according to different stages of forest regeneration. Urban conservation units can be of great importance in land management and in the sustainable development process of cities. Monitoring soil quality in these spaces can help to define strategies in the forest recovery process. A management performance evaluation method and consequent soil quality was applied, using data envelopment analysis (DEA). Soil was collected in the three stages of forest regeneration observed, land with established forests, reforested land, and open land, at three different depths. In the set of 54 analyzed observations, soils with low levels of fertility were verified. However, an area with reforested land showed the best performance in maximizing the selected variables and consequently better soil quality scores. The open lands showed the lowest performance in soil conservation. In this way, the revealed performance scores accompanied the Sum of Exchangeable Bases and Organic Matter values. This quality score can help to define soil management strategies, which may be applicable to a wider audience and wider contexts in environmental management

    Sugars profiles of different chestnut (Castanea sativa Mill.) and almond (Prunus dulcis) cultivars by HPLC-RI

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    Sugar profiles of different almond and chestnut cultivars were obtained by high-performance liquid chromatography (HPLC), by means of a refractive index (RI) detector. A solid-liquid extraction procedure was used in defatted and dried samples. The chromatographic separation was achieved using a Eurospher 100-5 NH2 column using an isocratic elution with acetonitrile/water (70:30, v/v) at a flow rate of 1.0 ml/min. All the compounds were separated in 16 min. The method was optimized and proved to be reproducible and accurate. Generally, more than 95% of sugars were identified for both matrixes. Sugars profiles were quite homogeneous for almond cultivars; sucrose was the main sugar (11.46±0.14 in Marcona to 22.23±0.59 in Ferragnes g/100 g of dried weight), followed by raffinose (0.71±0.05 in Ferraduel to 2.11±0.29 in Duro Italiano), glucose (0.42±0.12 in Pegarinhos two seeded to 1.47±0.19 in Ferragnes) and fructose (0.11±0.02 in Pegarinhos two seeded to 0.59±0.05 in Gloriette). Commercial cultivars proved to have higher sucrose contents, except in the case of Marcona. Nevertheless, chestnut cultivars revealed a high heterogeneity. Sucrose was the main sugar in Aveleira (22.05±1.48), Judia (23.30±0.83) and Longal (9.56± 0.91), while glucose was slightly prevalent in Boa Ventura (6.63±0.49). The observed variance could serve for intercultivar discrimination

    Antioxidant potential of chestnut (Castanea sativa L.) and almond (Prunus dulcis L.) by-products.

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    The antioxidant properties of almond green husks (Cvs. Duro Italiano, Ferraduel, Ferranhês, Ferrastar and Orelha de Mula), chestnut skins and chestnut leaves (Cvs. Aveleira, Boa Ventura, Judia and Longal) were evaluated through several chemical and biochemical assays in order to provide a novel strategy to stimulate the application of waste products as new suppliers of useful bioactive compounds, namely antioxidants. All the assayed by-products revealed good antioxidant properties, with very low EC50 values (lower than 380 μg/mL), particularly for lipid peroxidation inhibition (lower than 140 μg/mL). The total phenols and flavonoids contents were also determined. The correlation between these bioactive compounds and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, inhibition of β-carotene bleaching and inhibition of lipid peroxidation in pig brain tissue through formation of thiobarbituric acid reactive substances, was also obtained. Although, all the assayed by-products proved to have a high potential of application in new antioxidants formulations, chestnut skins and leaves demonstrated better results

    Antioxidant activities of the extracts from chestnut flower, leaf, skins and fruit

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    In this study, the antioxidant properties of chestnut (flowers, leaves, skins and fruits) extracts were evaluated through several biochemical assays: DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity, reducing power, inhibition of β-carotene bleaching, inhibition of oxidative hemolysis in erythrocytes, induced by 2,2′-azobis(2-amidinopropane)dihydrochloride (AAPH), and inhibition of lipid peroxidation in pig brain tissue through the formation of thiobarbituric acid-reactive substances (TBARS). These assays have been extensively studied as models for the peroxidative damage in biomembranes. The EC50 values were calculated for all the methods in order to evaluate the antioxidant efficiency of each chestnut extract. The phenol and flavonoid contents were also obtained. Chestnut skins revealed the best antioxidant properties, presenting much lower EC50 values, particularly for lipid peroxidation inhibition in the TBARS assay. Furthermore, the highest antioxidant contents (polyphenols and flavonoids) were found for these extracts

    Antioxidant activity and bioactive compounds of ten Portuguese regional and commercial almond cultivars.

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    The antioxidant properties of different almond cultivars (cv.), either regional (Casanova, Duro Italiano, Molar, Orelha de Mula and Pegarinhos cv.) or commercial (Ferraduel, Ferranhês, Ferrastar and Guara cv.) were evaluated through several chemical and biochemical assays: DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, inhibition of b-carotene bleaching, inhibition of oxidative hemolysis in erythrocytes, induced by 2,20-azobis(2-amidinopropane)dihydrochloride (AAPH), and inhibition of thiobarbituric acid reactive substances (TBARS) formation in brain cells, all used as models for the lipid peroxidation damage in biomembranes. The EC50 values were calculated for all the methods in order to evaluate the antioxidant efficiency of each almond cultivar. Bioactive compounds such as phenols and flavonoids were also obtained and correlated to antioxidant activity. The results obtained were quite heterogeneous, revealing significant differences among the cultivars assayed. Duro Italiano cv. revealed better antioxidant properties, presenting lower EC50 values in all assays, and the highest antioxidants contents. The protective effect of this cultivar on erythrocyte biomembrane hemolysis was maintained during 4 h

    Effects of different phenols extraction conditions on antioxidant activity of almond (Prunus dulcis) fruits

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    In order to determine the optimum operational conditions for phenols extraction, a series of assays were performed in the Guara variety of almond (Prunus dulcis). Four variable operational conditions factors were considered: solvent type, solvent volume, temperature and extraction time. Phenols extracts antioxidant properties were evaluated, either chemically, by screening the free radical scavenging activity, or biochemically, by measuring the inhibition of thiobarbituric acid reactive substances formation in brain cells used as model for the study of lipid peroxidation damage in biomembranes. The extraction of the totality of phenols, confirmed by their antioxidant properties, allows the calculation of ideal doses for almond intake concerning antioxidant effects. The best outcome, regarding these proposals was obtained in the following conditions: 50 mL of methanol with 60 min of extraction time at 25C
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