1,788 research outputs found
Dataset of human interventions as anthropogenic perturbations on the Caribbean coast of Colombia
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
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
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
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.
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
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.
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
Determination of sugars in chestnut (Castanea sativa Mill.) cultivars from Portugal Northeast region by HPLC-RI
Effects of different phenols extraction conditions on antioxidant activity of almond (Prunus dulcis) fruits
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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