خيارات البحث
النتائج 2391 - 2400 من 62,508
Chemistry of Sulfur-Contaminated Soil Substrate from a Former Frasch Extraction Method Sulfur Mine Leachate with Various Forms of Litter in a Controlled Experiment النص الكامل
Justyna Likus-Cieślik | Marcin Pietrzykowski | Marcin Chodak
The impact of tree litter on soil chemistry leachate and sulfurous substrates of mine soils from former Jeziórko sulfur mine was investigated. Composites were used: soil substrate (less contaminated at mean 5090 mg kg−1 S or high contaminated at 42,500 mg kg−1 S)thinspace+thinspacebirch or pine litter and control substrate (no litter). The composites were rinsed with distilled water over 12 weeks. In the obtained leachate, pH, EC, dissolved organic carbon, N, Ca, Mg, Al, and S were determined. Physicochemical parameters of the substrates and their basal respiration rate were determined. Rinsing and litter application lowered sulfur concentration in high contamination substrates. Pine litter application decreased EC and increased pH of the low-contaminated substrate. The substrate pH remained at low phytotoxic level (i.e., below 3.0), resulting in the low biological activity of the composites. Birch litter application increased leaching of N and Mg, indicating the possibility of an intensification of soil-forming processes in contaminated sites. | Frasch method, Remediation, Sulfur contamination, Organic matter | 25 | 1-14 | 3
اظهر المزيد [+] اقل [-]Modifications in the structure of the lichen Cladonia thallus in the aftermath of habitat contamination and implications for its heavy-metal accumulation capacity النص الكامل
Piotr Osyczka | Piotr Boroń | Anna Lenart-Boroń | Kaja Rola
Phenotypic traits of lichens can be greatly modified by environmental factors. Granulose thalli on soil and podetia, densely covered with granules, referring to common and widespread lichen Cladonia cervicornis subsp. verticillata were found near zinc smelter. The granules are stratified, filled with fungal medulla and heavily encrusted with calcium oxalate weddellite crystals, not observed on regularly developed thalli of the species. Phylogenetic analysis revealed that deformed granulose forms belong to this taxon, showing that the phenotypic plasticity of the lichens of Cladonia can lead to the emergence of features that do not coincide with the taxonomic definition of the species. The heavy-metal accumulation capacity of both granulose and regular form of primary and secondary lichen thallus, in relation to the element content in corresponding substrate, was determined. Granulose-modified thalli accumulate greater amounts of heavy metals than regular ones, meaning that the bioaccumulation property of a given species may be greatly affected by morphological modifications. The granulose forms are also characterised by considerably higher ratios of Cd, Pb and As concentrations in lichen samples in relation to the corresponding substrates than regular ones. This means that collection of variously formed thalli should be avoided in biomonitoring sampling procedures. The results indicate that a substantial part of the element load, in particular zinc, in the examined lichen thalli collected near the smelter originates from atmospheric fallout. | Lichenized fungi; Phenotypic plasticity; Heavy metals; Bioaccumulation; Oxalate crystals; Biomonitoring; Thallus anatomy | 30 | 1950-1961 | 2
اظهر المزيد [+] اقل [-]Comparative Assessment of response to cadmium in heavy metal-tolerant shrubs cultured in vitro النص الكامل
Alina Wiszniewska | Ewa Hanus-Fajerska | Ewa Muszyńska | Sylwester Smoleń
Two species of Pb-adapted shrubs, Alyssum montanum and Daphne jasminea, were evaluated in vitro for their tolerance to elevated concentrations of cadmium. Shoot cultures were treated with 0.5, 2.5, and 5.0 μM CdCl2 for 16 weeks and analyzed for their organogenic response, biomass accretion, pigment content, and macronutrient status. Cadmium accumulation and its root-to-shoot translocation were also determined. In both species, rooted microplantlets, suitable for acclimatization, were obtained in the presence of Cd applied as selection agent. In A. montanum, low and moderate dose of Cd stimulated multiplication, rooting, and biomass production. Growth tolerance index (GTI) in Cd-treated shoots ranged from 120 to 215%, while in the roots 51–202%. In turn, in Cd-treated D. jasminea proliferation and rooting were inhibited, and GTI for shoots decreased with increasing doses of Cd. However, roots exposed to Cd had higher biomass accretion. Both species accumulated Cd in developed organs, and its content increased with increasing CdCl2 dose. Interestingly, D. jasminea accumulated higher amounts of Cd in the roots than A. montanum and immobilized this metal in the root system. On the contrary, A. montanum translocated some part of accumulated Cd to the shoots, but with low efficiency. In the presence of Cd, A. montanum maintained macronutrient homeostasis and synthesized higher amounts of phytosynthetic pigments in the shoots. D. jasminea accumulated root biomass, immobilized Cd, and restricted its translocation at the expense of nutrient balance. Considering remediation potential, A. montanum could be exploited in phytoextraction, while D. jasminea in phytostabilization of polluted substrate. | Alyssum montanum Daphne jasminea Metallophyte Toxicity Trace metal | 25 | 1-13 | 8, Article:304
اظهر المزيد [+] اقل [-]Short-term impact of different doses of spent coffee grounds, salt, and sand on soil chemical and hydrological properties in an urban soil النص الكامل
Muhammad Owais Khan | Anna Klamerus-Iwan | Dawid Kupka | Ewa Słowik-Opoka
Natural and human activities have deteriorated urban soil’s health and ecological functions as compared to forest soils. Therefore, we hypothesized that any intervention in poor quality soil in urban area will change their chemical and water retention properties. The experiment was conducted in Krakow (Poland) in completely randomized design (CRD). The soil amendments used in this experiment consisted of control, spent coffee grounds (SCGs), salt, and sand (1 and 2 t ha−1) in order to evaluate the impact of these soil amendments on the urban soil chemical and hydrological properties. Soil samples were collected after 3 months of soil application. The soil pH, soil acidity (me/100 g), electrical conductivity (mS/cm), total carbon (%), CO2 emission (g m−2 day−1), and total nitrogen (%) were measured in laboratory condition. The soil hydrological properties like volumetric water content (VWC), water drop penetration time (WDPT), current water storage capacity (Sa), water storage capacity after 4 and 24 h (S4 and S24), and capillary water Pk (mm) were also determined. We noted variations in soil chemical and water retention properties in urban soil after the application of SCGs, sand, and salt. It was observed that SCGs (2 t ha−1) has reduced soil pH and nitrogen (%) by 14 and 9%, while the incorporation of salt resulted in maximum soil EC, total acidity, and soil pH. The soil carbon (%) and CO2 emission (g m−2 day−1) were enhanced and declined by SCGs amendment. Furthermore, the soil hydrological properties were significantly influenced by the soil amendment (spent coffee grounds, salt, and sand) application. Our results showed that spent coffee grounds mixing in urban soil has considerably enhanced the soil VWC, Sa, S4, S24, and Pk, whereas it decreased the water drop penetration time. The analysis showed that the single dose of soil amendments had not improved soil chemical properties very well. Therefore, it is suggested that SCGs should be applied more than single dose. This is a good direction to look for ways to improve the retention properties of urban soil and you can consider combining SCGs with other organic materials like compost, farmyard manure, or biochar. | Total carbon, Carbon dioxide emission, WDPT, Volumetric water content, Water storage capacity | 100 | 86218–86231 | 30
اظهر المزيد [+] اقل [-]Microplastic on Mountain Trails—a Case Study from the Carpathian and Sudetes Mountains in Poland النص الكامل
Jarosław Lasota | Ewa Błońska | Wojciech Piaszczyk | Sylwester Tabor
Microplastics are becoming an increasingly common pollutant that can pose a threat to living organisms. The aim of this research was to determine the amount, type, and diversity of microplastics along mountain trails. The study includes three mountain trails, differing in terms of length, difficulty, and number of visitors. The trails were located in the massif of Babia Góra, in the Kościeliska Valley, and Izerska Meadow. During the research, microplastics were determined in snow during the winter period. The research shows high microplastic contamination along the trails. The study area was characterized by the highest content of polyurethane, polyethylene terephthalate, polyethylene, and polypropylene. The tiniest plastic below 0.5 mm dominated in all the sampling points, with a small share of sizes within the range of 3.1-4.0 mm and 4.1-5.0 mm. The isolated microplastics varied in color and shape. The conducted analyses confirm that easier, more frequented trails are characterized by a higher content of microplastics. Trails to Babia Góra, which are more demanding, are characterized by a different composition of microplastics as well as a variety of microplastics in terms of size, shape, and color. In addition, the lower-lying fragments of the examined trails were the most heavily contaminated with microplastics. The results indicate the need for further research on microplastic contamination of the soil environment along mountain trails. | Human activity, Microplastics, Mountain areas, Snow, Sources | 70 | 1-10
اظهر المزيد [+] اقل [-]Nocturnal noise and habitat homogeneity limit species richness of owls in an urban environment النص الكامل
Arkadiusz Fröhlich | Michał Ciach
Habitat loss and fragmentation are listed among the most significant effects of urbanization, which is regarded as an importantthreat to wildlife. Owls are the top predators in most terrestrial habitats, and their presence is a reliable indicator of ecosystemquality and complexity. However, influence of urbanization on owl communities, anthropogenic noise in particular, has not beeninvestigated so far. The aim of this study was to identify the role of noise and landcover heterogeneity in the species richness ofowl assemblage in the urban ecosystem. Owls were surveyed in the city of Kraków (southern Poland) on 65 randomly selectedsample plots (1 km2). The area of main landcover types, landcover diversity index, mean size of landcover patch, and nocturnalnoise level were defined within the sample plots and correlated with owl species richness. Five owl species were recorded in thestudy area with forests as the dominant landcover type for Tawny and Ural owls, grasslands for Long-eared and Barn owls, andgardens for Little owls. In total, 52% of sample plots were occupied by at least one species (1–3 species per plot). The number ofowl species was positively correlated with landcover diversity index and negatively correlated with nocturnal noise emission.This study demonstrates that species richness of owls in urban areas may be shaped by landcover heterogeneity and limited bynoise intensity. This indicates that noise changes top predator assemblage, which in consequence may disturb predator-preyinteractions within human-transformed habitats. | Urban ecology, Acoustic predators, Traffic noise, Habitat diversity, Habitat homogenization, Strigiformes | 100 | 17284-17291 | 17
اظهر المزيد [+] اقل [-]Spatiotemporal Variability in Microbiological Water Quality of the Białka River and Its Relation to the Selected Physicochemical Parameters of Water النص الكامل
Anna Lenart-Boroń | Anna Wolanin | Łukasz Jelonkiewicz | Daria Chmielewska-Błotnicka | Mirosław Żelazny
The aim of this 2-year study was to examine the temporal changes in the concentration of microbiological indicators of water contamination and selected physicochemical parameters within the Białka river and its selected tributaries in the vicinity of the largest ski station in Białka Tatrzańska. The study involved 24 series of sampling in eight sites throughout the Białka river and on its selected tributaries. Temperature, pH, and electrical conductivity (EC25 °C) were measured onsite. The microbiological assays included the numbers of mesophilic and psychrophilic bacteria, Staphylococcus spp. and Salmonella spp., as well as coliforms, thermotolerant (fecal) coliforms, Escherichia coli, Enterococcus faecalis, and sulfate-reducing Clostridium. The chemical analyses were conducted to determine the concentration of NH4+, NO2−, NO3−, and PO43−. The analyses showed that contrary to common opinion, waters of the Białka river are strongly polluted in some sections. Seasonal variation in the prevalence of microbial indicators of fecal pollution was found, and the largest numbers of microorganisms were observed in winter ski season, followed by summer holidays. Similar seasonal pattern was observed in the examined chemical parameters. There was also very strong spatial variation within the tested microbial and chemical parameters, indicating the presence of pollution hotspots in the course of the Białka river. The employed principal component analysis revealed the presence of two main pollution sources, mainly affecting the quality of river water, i.e., fecal contamination of human origin and the natural source in the form of surface runoff and soil leaching. These factors, depending on the location of the sampling site, occurred in different configurations. | Białka river, Spatiotemporal variability, Microbiological quality, Fecal contamination, Nutrients, Principal component analysis | 25 | 1-12 | 1
اظهر المزيد [+] اقل [-]Spatial distribution of trace elements and ecotoxicity of bottom sediments in Rybnik reservoir, Silesian-Poland النص الكامل
Agnieszka Baran | Marek Tarnawski | Tomasz Koniarz
The aim of study was to integrate chemical analyses and toxicity bioassays in order to assess the environmental risk connected with the presence of trace elements in the sediments. This study examined the ecological significance of trace elements in bottom sediments by applying a set of complementary sediment quality assessment methods sediment quality guidelines (SQGs) (mean probable effect concentration quotient (PECQ)), potential ecological risk index (PERI), contamination degree (Cd) and two bioassays: the bacterial luminescence inhibition test with Vibrio fischeri on sediment elutriates and the direct contact test with the ostracod crustacean Heterocypris incongruens. The samples were collected from 50 stations of Rybnik reservoir. The reservoir is a region with enormous concentration of industry, mainly hard coal mining, electric power industry, and transportation. Despite the high diversity in metal concentration in the sediments, the spatial distribution of trace elements in the sediments was very similar. Moreover, the strong positive correlations between individual pairs of trace elements indicate that they may derive from a similar source and move together. According to mean PECQs, 68 % of the samples were potentially non-toxic and 32 % of the samples were potentially toxic. PERI values suggested that 70 % of the sediment sampling sites exhibited low ecological risk from metal pollution while 24 % of the samples had severe and serious risk. Based on our combined evaluation, we believe that Cd and Cu in the sediment samples frequently caused adverse biological effects. Higher toxic responses were observed in the Microtox test than in the Ostracodtoxkit test. All the sediment samples were found toxic to V. fischeri, and 96 % of the samples had effect percentages >50 %. For H. incongruens, 12 % of the sediments were not toxic and 44 % had effect percentages >50 %. In order to perform a complex assessment of the environmental impact of metal pollution, both chemical and ecotoxicological analysis should be carried out. | Bottom sediment, Spatial distribution, Trace elements, Biotest, Ecological risk assessment | 30 | 1-13 | 17
اظهر المزيد [+] اقل [-]Potential for chromium (VI) bioremediation by the aquatic carnivorous plant Utricularia gibba L. (Lentibulariaceae) النص الكامل
Joanna Augustynowicz | Krzysztof Łukowicz | Krzysztof Tokarz | Bartosz Płachno
The aquatic carnivorous plant Utricularia gibba has one of the smallest known genomes among flowering plants, and therefore, it is an excellent model organism for physiological and developmental studies. The main aim of our work was to check whether the ubiquitous U. gibba might be useful for the phytoremediation of the highly toxic and mobile hexavalent chromium in waters. Plants were incubated for 1 week in a 50 μM (2.6 mg dm(-3)) Cr(VI) solution in laboratory conditions. Our results revealed that the plant exhibits a very high accumulation capacity for Cr. The accumulation level was higher than 780 mg kg(-1) and a bioconcentration factor >300. On the other hand, the plants showed a low tolerance to the elevated Cr concentration, which was expressed in a significant decrease of the photosystem II activity. However, the most pronounced negative influence of chromate was found on the morphology and activity of the traps. Due to its high accumulation capacity, we suggest that U. gibba may be efficient in the removal of chromate over a short time scale. It can also provide a new molecular resource for studying the mechanisms of Cr(VI) detoxification. | Aquatic carnivorous plants, chlorophyll fluorescence, chromium, heavy metals, phytoremediation | 30 | 9742-9748 | 13
اظهر المزيد [+] اقل [-]Tetrabromobisphenol A (TBBPA)-stimulated reactive oxygen species (ROS) production in cell-free model using the 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) assay - limitations of method النص الكامل
2016
Konrad A. Szychowski | Kamila Rybczyńska-Tkaczyk | Marcin L. Leja | Anna Wójtowicz | Jan Gmiński
Tetrabromobisphenol A (TBBPA)-stimulated reactive oxygen species (ROS) production in cell-free model using the 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) assay - limitations of method النص الكامل
Konrad A. Szychowski | Kamila Rybczyńska-Tkaczyk | Marcin L. Leja | Anna Wójtowicz | Jan Gmiński
Tetrabromobisphenol A (TBBPA) is a widely used brominated flame retardant, applied in a variety of commercial and household products, mainly electronic ones. Since the production of reactive oxygen species (ROS) is considered one of the principal cytotoxicity mechanisms, numerous studies undertake that aspect of TBBPA’s mechanism of action. The present study verifies if the fluorogenic substrate 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) should be used to detect ROS production induced by TBBPA. To determine the ability of TBBPA alone to stimulate the conversion of H2DCFDA to its fluorescent product 2’,7’-dichlorofluorescein (DCF), we used a cell-free model. In the experiments we check different cultured media also in combination with free radical scavenger N-acetyl-l-cysteine (NAC). Additionally, experiments with stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH·) have been made. The presented data showed that TBBPA in all tested concentrations interacts with H2DCFDA in phosphate-buffered saline (PBS) buffer while in micromolar concentrations in the DMEM/F12 medium with and without serum. The addition of NAC inhibited the interaction of TBBPA with H2DCFDA. Experiments with DPPH· showed that, in the presence of NAC, TBBPA acts like a free radical. TBBPA has similar properties to free radical and is susceptible to free radical scavenging properties of NAC. Our results indicated that H2DCFDA assay cannot be used to evaluate cellular ROS production in TBBPA studies. The study connected with TBBPA-stimulated ROS production in cell culture models using the H2DCFDA assay should be revised using a different method. However, due to the free radical-like nature of TBBPA, it can be very difficult. Therefore, further investigation of the nature of TBBPA as a compound with similar properties to free radical is required. | TBBPA, Free radical, H2DCFDA, DPPH, ROS | 30 | 12246-12252 | 23
اظهر المزيد [+] اقل [-]Tetrabromobisphenol A (TBBPA)-stimulated reactive oxygen species (ROS) production in cell-free model using the 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) assay—limitations of method النص الكامل
2016
Szychowski, Konrad A. | Rybczyńska-Tkaczyk, Kamila | Leja, Marcin L. | Wójtowicz, Anna K. | Gmiński, Jan
Tetrabromobisphenol A (TBBPA) is a widely used brominated flame retardant, applied in a variety of commercial and household products, mainly electronic ones. Since the production of reactive oxygen species (ROS) is considered one of the principal cytotoxicity mechanisms, numerous studies undertake that aspect of TBBPA’s mechanism of action. The present study verifies if the fluorogenic substrate 2′,7′-dichlorodihydrofluorescein diacetate (H₂DCFDA) should be used to detect ROS production induced by TBBPA. To determine the ability of TBBPA alone to stimulate the conversion of H₂DCFDA to its fluorescent product 2’,7’-dichlorofluorescein (DCF), we used a cell-free model. In the experiments we check different cultured media also in combination with free radical scavenger N-acetyl-l-cysteine (NAC). Additionally, experiments with stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH·) have been made. The presented data showed that TBBPA in all tested concentrations interacts with H₂DCFDA in phosphate-buffered saline (PBS) buffer while in micromolar concentrations in the DMEM/F12 medium with and without serum. The addition of NAC inhibited the interaction of TBBPA with H₂DCFDA. Experiments with DPPH· showed that, in the presence of NAC, TBBPA acts like a free radical. TBBPA has similar properties to free radical and is susceptible to free radical scavenging properties of NAC. Our results indicated that H2DCFDA assay cannot be used to evaluate cellular ROS production in TBBPA studies. The study connected with TBBPA-stimulated ROS production in cell culture models using the H2DCFDA assay should be revised using a different method. However, due to the free radical-like nature of TBBPA, it can be very difficult. Therefore, further investigation of the nature of TBBPA as a compound with similar properties to free radical is required.
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