Swarzędzkie Lake (near Poznań) has been heavily polluted. To improve the water quality, the restoration of lake by three methods: aeration, phosphorus inactivation using small doses of iron sulphate ...and magnesium chloride (FeSO4 and MgCl2) and biomanipulation was initiated at the end of 2011. The aim of the present study was to determine whether sustainable restoration has a significant impact on phytoplankton, especially cyanobacterial blooms in a shallow, urban, degraded lake. Therefore, phytoplankton and the physico-chemical parameters of water at the summer thermal stratification and autumn water mixing before (2011) and during restoration (2012–2014) was studied.
Samples were collected at the deepest place of the lake in depth profile, every 1 m. Phytoplankton samples were preserved with Lugol's solution. The phytoplankton was counted using a Sedgewick-Rafter chamber with a volume of 0.46 ml. Measurements of water temperature were made in the field with a YSI multiparameter meter, transparency – using a Secchi disk. Concentrations of nitrogen, phosphorus and chlorophyll a were analysed in the laboratory according to Polish standards.
As a result of restoration the water quality of the lake has improved. Cyanobacteria had almost disappeared during the first year of restoration, however, a short bloom was observed (dominated by Pseudanabeana limnetica) in the second year. The main reason for this reappearance was a higher water temperature stimulating cyanobacteria growth, but an increased supply of phosphorus from the bottom sediments also contributed. A decrease in the temperature in the third year of restoration limited the growth of cyanobacteria again. Although the decrease in the phosphorus concentration as a result of restoration proved to be sufficient for average climatic conditions, it is highly likely to be more intense in the case of increased water temperature caused by global warming.
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•Sustainable restoration improved the lake water quality.•Strong reconstruction of phytoplankton composition was observed.•Short cyanobacterial water bloom appeared only in the second year of restoration.•Cyanobacteria growth was stimulated by high temperature and elevated internal loading.•Phosphorus decrease proved to be sufficient only for average climatic conditions.
Many lakes worldwide, especially shallow, experience great changes due to eutrophication, manifested in severe, usually toxic water blooms, disqualifying them from recreation. In order to improve ...water quality, restoration programs are implemented, including numerous methods. Intense nutrient cycling resulting from detrimental role of sediments impede obtaining of clear water state. One of the restoration methods proposed in recent years was Effective Microorganisms (EM), i.e. the set of microorganisms aiming at the inhibition of harmful bacteria through competitive exclusion. This approach was introduced in shallow Konin Lake (Western Poland), suffering from severe cyanobacterial water blooms. Prior to the treatment, protective action was conducted i.e. the elimination of external nutrient loads with backwater from the river. Changes in water chemistry, phytoplankton structure and macrophytes distribution were noted during the 5-year studies (2011–2015), covering the treatment (2013–2015) as well as two previous years. Oscillatoriacean cyanobacteria were most abundant in (2011−2012), while Nostocales in summer 2014–2015, as a result of decreased phosphorus but increased nitrogen concentrations. Slight increase in Cladoceran zooplankton was observed, but none in submerged macrophytes due to low water transparency. EM application initiated positive changes in the ecosystem by means of excessive organic matter decomposition and increased diversity of phytoplankton, nevertheless cyanobacteria blooms were still present due to high nutrient content.
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•Shallow lake, restored by EM and barley straw, was under 5-year research.•Phyto- and zooplankton structure changed in spring due to protective treatment.•Ammonium N concentrations increased, while P content decreased during the research.•Cyanobacteria were still dominants in phytoplankton afterwards the restoration.•A shift from Oscillatoriacean to Nostocales in summer was noted.
There is a pressing need to identify novel antiplatelet agents, an alternative to acetylsalicylic acid and thienopyridines, to broaden the prevention of cardiovascular events, the leading cause of ...global morbidity and mortality. Invertebrate coelomocytes structurally and functionally resemble the thrombocyte-like cells of vertebrates; therefore, the coelomic fluid in which they are suspended may contain agents controlling their clumping abilities. However, whether coelomocytes-free coelomic fluid may also affect human platelet activities was not a subject of any study. This study aimed to screen the in vitro antiplatelet and anticoagulant activities of the polysaccharide-protein complex from Dendrobaena veneta coelomic fluid (25–100 µg/mL) (PPC-DV). All tested fluid concentrations induced significant (42.4–52.5%) inhibition of adenosine-5′-diphosphate (ADP)-induced aggregation of human platelets at a level comparable to that of 140 µmol/L acetylsalicylic acid. Its relevant antiplatelet effect (27.2–45.9%) was also evidenced in the thrombin receptor-activating peptide-6 (TRAP-6) assay. Moreover, 50 and 100 µg/mL of PPC-DV inhibited arachidonic acid-inducible aggregation. No coagulopathic or cytotoxic effects of PPC-DV were observed. The study indicates that PPC-DV, at a concentration of at least 50 µg/mL, exerts a favorable antiplatelet effect by targeting at least three pathways (P2Y12 receptor, cyclooxygenase-1, and protease-activated receptor-1), justifying further experimental and clinical investigations on its use in cardiovascular disease prevention.
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•PPC-DV inhibited P2Y12, COX-1 and PAR-1 in human platelets.•The effect on P2Y12 was comparable to that of acetylsalicylic acid.•PPC-DV did not affect prothrombin time and INR.•No cytotoxicity of coelomic fluid was observed.•Further studies on the use of PPC-DV fluid in CVD are needed.
When exploring the challenges of restoring degraded lakes, we often do not observe the expected results despite executing all planned activities. Our study elucidates the reasons that impede the ...recovery of submerged macrophytes despite ameliorated light conditions. When prolonged lake degradation occurs, subsequent efforts to increase light availability often prove insufficient, resulting in a persistent turbid water state. In this study, we attempted to determine the reasons for these failures through a germination test and propagule bank analysis conducted in bottom sediments from a severely degraded lake, which underwent restoration. Although the bottom sediments indicate relative potential in the number of oospores and seeds, their germination efficacy remained dismally low. Based on the germination test results and factors affecting the development of submerged macrophytes (physical and chemical parameters, lake morphology), we stated that improvement of light conditions in the lake could be insufficient to recover the vegetation, especially when the potential to renew diverse plant communities from sediments naturally is low. Our findings advocate for a paradigmatic shift in lake restoration strategies. A holistic approach that includes propagule bank assessments before embarking on restoration initiatives and enabling the identification of macrophyte resurgence potentials is recommended. We also advocate for a multifaceted restoration framework, emphasizing the indispensability of augmenting natural recovery mechanisms with targeted interventions. Consequently, in some cases, macrophyte reintroduction could be the only solution. By reintroducing autochthonic species to site-specific ecological dynamics, we anticipate an increased success rate in restituting submerged vegetation, thus catalyzing ecological regeneration within degraded lake ecosystems.
Long-term cyanobacterial blooms and hypereutrophic state have been typical for the shallow, urban Swarzędzkie Lake for many years. Diversion of sewage did not change its trophic status, so ...restoration began in autumn 2011 using the sustainable approach based on three methods. The aim of the study was to analyse how sustainable restoration affects zooplankton. We hypothesised that bottom-up and top-down methods reconstructed zooplankton composition. Thus, the abundance of large-size cladocerans increased and controlled phytoplankton effectively. The elimination of cyanobacteria bloom, the decrease of rotifer abundance and the twofold increase of filter-feeder effectiveness were observed in summer 2012. However, high phosphorus concentration, lack of regular cyprinid removal and insufficient fish stocking together with high temperature prevented zooplankton from controlling cyanobacteria bloom in summer 2013. Rotifer domination with high trophy species was noted, as before restoration. The number of rotifers decreased in 2014, while crustaceans increased due to the significant decrease of nutrient concentrations and an intensification of biomanipulation treatments. Therefore, summer phytoplankton growth was low, without cyanobacteria dominance. The rebuilding of zooplankton in Swarzędzkie Lake was observed during sustainable restoration. However, the treatments should be intensified when adverse changes were observed to obtain better results for the improvement of water quality.
Air pollution, to which children are more susceptible than adults, can promote airway inflammation, potentially exaggerating the effects of respiratory viral infection. This study examined the ...association between the clinical manifestation of COVID-19 in unvaccinated pediatric patients hospitalized in Poland (n = 766) and levels of particulate matter 2.5 (PM2.5) and benzo(a)pyrene (B(a)P) within a week before hospitalization. Children aged ≤ 12 years exposed to mean and max 24 h B(a)P levels > 1 ng/m3 revealed higher odds of cough, dyspnea, fever, and increased concentrations of inflammatory markers (C-reactive protein, interleukin-6, procalcitonin, white blood cell count). In older patients (13–17 years), elevated mean 24 h B(a)P levels increased odds of dyspnea, fever, and diarrhea, and higher concentrations of C-reactive protein and procalcitonin. Exposure to max 24 h PM2.5 levels > 20 µg/m3 was associated with higher odds of cough, increased concentrations of C-reactive protein (group ≤12 years), and increased procalcitonin concentration (groups ≤12 years and 13–17 years). In both age groups, length of stay was extended in patients exposed to elevated levels of max 24 h PM2.5, mean and max 24 h B(a)P. This study suggests that worse air quality, particularly reflected in increased B(a)P levels, might affect the clinical course of COVID-19 in pediatric patients and adds to the disease burden during a pandemic.
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•The role of air pollution in the clinical course of COVID-19 in children was examined.•Air pollutants affected symptomatology of COVID-19.•Exposure to B(a)P increased odds for hyperinflammation.•B(a)P exposure extended hospital stay.•Air pollution adds to the COVID-19 health burden in pediatric groups.
Long COVID (LC) is characterized by persistent symptoms following SARS-CoV-2 infection, with various mechanisms offered to explain its pathogenesis. This study explored whether adaptive humoral ...anti-SARS-CoV-2 responses differ in LC. Unvaccinated COVID-19 convalescents (n = 200) were enrolled, with 21.5% (n = 43) presenting LC three months post-infection. LC diagnosis was based on persistent symptom(s) and alterations in biochemical/clinical markers; three phenotypes were distinguished: cardiological, pulmonary, and psychiatric LC. All three phenotypes were characterized by significantly decreased seroprevalence of IgG antibodies against nucleocapsid (anti-NP). LC was associated with decreased odds of testing positive for anti-NP (OR = 0.35, 95%CI: 0.16–0.78, p = 0.001). Seropositive LC patients had lower anti-S1 and anti-S2 levels than individuals without LC, and those with pulmonary and psychological phenotypes also revealed decreased anti-RBD concentrations. The results indicate that LC can be characterized by diminished humoral response to SARS-CoV-2. The potential implication of this phenomenon in post-acute viral sequelae is discussed.
•Humoral response in cardiological, pulmonary and psychiatric long COVID was studied.•Long COVID was diagnosed based on symptoms and objective clinical screening.•No enhanced adaptive humoral immunity in Long COVID was confirmed.•Long COVID patients had lower seroprevalence of anti-nucleocapsid IgGs.•Particular Long COVID phenotypes were associated with lower antibody levels.
To fill the knowledge gap about the functioning of the lake–river system subjected to restoration treatments, two tributaries, a shallow, restored lake and its outflow, were examined. The quality of ...water inflows, lake and outflow was compared before (BR), during sustainable (SR, deep water aeration, phosphorus inactivation and biomanipulation for 3 years) and limited lake restoration (LR, only aeration for 2 years). Physico-chemical parameters were analysed monthly at five stations. The nutrient concentrations at the inflows decreased over the years due to the improvement of water and sewage management in the catchment (in Mielcuch from 18.0 to 8.0 mgN L
−1
and 1.0 to 0.6 mgP L
−1
). The decline at the outflow was the result of a better quality of water at the tributaries and SR in the lake. During LR, decrease of phosphorus concentration still occurred (0.11 mgP L
−1
), but nitrogen concentration slightly increased (3.9 mgN L
−1
). Although the outflowing waters still transported a high content of chlorophyll
a
and suspended solids during SR, their amount was lower (34.5 μg L
−1
and 17 mg L
−1
, respectively) than that during BR and LR. During restoration, it is significant to monitor the water quality not only in the lake but also at the outflow. The slow deterioration of water quality at the outflow indicated that introducing changes in the applied restoration methods must be done carefully because the previously achieved effect may be lost. Hence, restoration of the upstream lake and good quality of its tributaries are of great importance for water bodies located downstream.
Cyanobacterial blooms and cyanotoxins occur in freshwater lakes and reservoirs all over the world. Bacterial degradation of microcystins (MC), hepatotoxins produced by several cyanobacterial species, ...has also been broadly documented. However, information regarding MC biodegradation in European water bodies is very limited. In this paper, the occurrence and identification of MC biodegradation products was documented for 21 European lakes and reservoirs, many of which have well-documented cyanobacterial bloom histories. Varying cyanobacterial abundance and taxonomical composition were documented and MC producers were found in all the analysed samples. Planktothrix agardhii was the most common cyanobacterial species and it formed mass occurrences in four lakes. MC biodegradation was observed in 86% of the samples (18 out of 21), and four products of dmMC-LR decomposition were detected by HPLC and LC-MS methods. The two main products were cyclic dmMC-LR with modifications in the Arg-Asp-Leu region; additionally one product was recognized as the tetrapeptide Adda-Glu-Mdha-Ala. The composition of the detected products suggested a new biochemical pathway of MC degradation. The results confirmed the hypothesis that microcystin biodegradation is a common phenomenon in central European waters and that it may occur by a mechanism which is different from the one previously reported. Such a finding implies the necessity to develop a more accurate methodology for screening bacteria with MC biodegradation ability. Furthermore, it warrants new basic and applied studies on the characterization and utilization of new MC-degrading strains and biodegradation pathways.
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