Are bioplastics an ecofriendly alternative to fossil fuel plastics?

Environmental Chemistry Letters - More than 390 million tons of fossil fuel plastics have been produced in 2022, and plastic pollution has become a major health issue for humans and ecosytems....     

Whole-lake dissolved inorganic 13C additions reveal seasonal shifts in zooplankton diet

Sustained whole-lake additions of 13C-enriched dissolved inorganic carbon (DIC), intended to increase experimentally the delta13C of DIC in the epilimnion of a small lake with high dissolved organic carbon (DOC), were made during three seasonal periods (spring, summer, and autumn). Coupled with carbon and nitrogen stable isotope analysis of zooplankton and several of their putative food sources, these additions were used to investigate seasonal changes in the relative contributions of different food sources to zooplankton diet in the lake. Four main potential food sources were considered: phytoplankton, heterotrophic bacteria (HB), methanotrophic bacteria (MOB), and green sulfur bacteria (GSB). Because the number of potential food sources exceeded the number of isotopes analyzed, a computer program (IsoSource) was used to estimate the range of possible contributions of the various food sources. During all three periods the added inorganic 13C quickly increased the epilimnetic DIC delta13C by between 18 per thousand and 21 per thousand above the initial value of approximately -21 per thousand. This 13C enrichment of DIC was rapidly transmitted to the particulate organic matter (POM), which included photosynthetic phytoplankton. In spring and summer, delta13C of both adult and juvenile Daphnia increased by approximately 10 per thousand, indicating that Daphnia utilized autochthonous carbon. However, this 13C labeling of Daphnia was not so obvious during the autumn period, when their delta13C generally decreased. According to the IsoSource model outputs based on both delta13C and delta15N values, Daphnia utilized all four potential food source types during spring, summer, and autumn, but in different proportions. The possible contribution of phytoplankton to Daphnia diet was substantial (25-71%) in all seasons. The possible contributions of the bacterial food sources were more variable. The possible contribution of GSB was minor (0-20%) at all times and negligible in autumn. The possible contribution of HB was higher but very variable. Methanotrophic bacteria always made a significant contribution to Daphnia diet and were likely the single most important food source in autumn. Since both HB and MOB in this high-DOC lake probably depend largely on allochthonous organic carbon, our results highlight the seasonal variability in the potential importance of ecosystem subsidies in lake food webs.     

Self-assessed driver competence among novice drivers - a comparison of driving test candidate assessments and examiner assessments in a Dutch and Finnish sample

Problem

This study examined novice drivers’ overconfidence by comparing their self-assessed driver competence with the assessments made by driving examiners.

Method

A Finnish (n = 2,739) and a Dutch sample (n = 239) of drivers license candidates assessed their driver competence in six areas and took the driving test.

Result and Discussion

In contrast to previous studies where drivers have assessed their skill in comparison to the average driver, a smaller proportion overestimated and a larger proportion made realistic self-assessments of their driver competence in the present study, where self-assessments were compared with examiner assessments. Between 40% and 50% of the candidates in both samples made realistic assessments and 30% to 40% overestimated their competence. The proportion of overestimation was greater in the Dutch than in the Finnish sample, which might be explained by greater possibilities for practicing self-assessment in the Finnish driver education system. Similar to other self-assessment studies that indicate that incompetence is related to overestimation, a larger proportion of candidates that failed the test overestimated their skill compared to those who passed. In contrast to other studies, males did not overestimate their skills more than females, and younger driver candidates were not more overconfident than older drivers.

Impact on traffic safety

Although a great proportion of the candidates made a realistic assessment of their own driver competence, overestimation is still a problem that needs to be dealt with. To improve the accuracy of novice drivers’ self-assessment, methods for self-assessment training should be developed and implemented in the driver licensing process.     

Analysis of a population of magnetotactic bacteria of the Gulf of Gabès,Tunisia

The occurrence of magnetotactic bacteria (MTB) on a Tunisian marine coast exposed to heavy metals pollution (Sfax, Gulf of Gabès, Mediterranean Sea) was investigated. The MTB population of this Southern Mediterranean coast was compared to the MTB populations previously investigated on the French Northern Mediterranean coast. A dominant MTB coccus morphotype was observed by microscopy analysis. By pyrosequencing technology, the analysis of the 16S ribosomal RNA (rDNA) revealed as much as 33 operational taxonomic sequence units (OTUs) close to sequences of MTB accessible in the databases. The majority were close to MTB sequences of the “Med group” of α-Proteobacteria. Among them, a dominant OTU_001 (99 % of the MTB sequences) affiliated within the Magnetococcales order was highlighted. Investigating the capacities of this novel bacterium to be used in bioremediation and/or depollution processes could be envisaged.     

Polyphenols dynamics and phytotoxicity in a soil amended by olive mill wastewaters

The effects of unprocessed olive mill wastewaters (OMW) on soil characteristics were investigated. Phenolic compounds levels in the treated soil were compared to those of a control soil profile. Results showed that OMW infiltration caused a modification of soil physicochemical characteristics. Phenolic compounds were detected at a depth of 1.2m four months after the last application of OMW. A moderate phytotoxic residual phenolic fraction (F) was extracted from the superficial soil layer 1 year after the OMW application. This residual F had a phytotoxic potential comparable to that of 25-fold diluted OMW.     

Mediterranean land systems under global change: current state and future challenges

Regional Environmental Change -     

Exploring the determinants for adopting water conservation measures. What is the tendency of landowners when the resource is already at risk?

In Finland, the current water conservation policy sets equal incentives for water conservation, regardless of the environmental condition. Before any policy reform, it is vital to investigate the tendency of landowners to adopt water conservation measures. In this study, we were interested in examining adoption if the soil quality implies a high leaching risk and if the water quality is already poor. By combining survey data with GIS data, we analysed the effect of farm and farmer characteristics and attitudes towards adoption. Our probit models indicated that financial variables were the key determinants of adoption for active farmers, whereas for passive owners, adoption was also explained by attitudes. In contrast to our expectations, adoption in areas under risk was weakly supported by our estimates. Environmental awareness, providing it increases with risk, is not strong enough to motivate adoption. Targeted agri-environmental measures, even though costly, cannot be avoided, and spatially tailored measures can attract adopters in hotspot areas.     

Development of Nanocomposite Films Based on Chitosan and Gelatin Loaded with Chitosan-Tripolyphosphate Nanoparticles: Antioxidant Potentials and Applications in Wound Healing

Journal of Polymers and the Environment - Recently, there is an increasing interest to prepare wound healing agents based on bio-polymers, due to their non-toxicity, biocompatibility and...     

Recent progress and challenges on the removal of per- and poly-fluoroalkyl substances (PFAS) from contaminated soil and water

Environmental Science and Pollution Research - Currently, due to an increase in urbanization and industrialization around the world, a large volume of per- and poly-fluoroalkyl substances (PFAS)...