The Ecotoxicity Approach as a Tool for Assessing Vermiremediation Effectiveness in Polychlorobiphenyls, Polychlorodibenzo-p-Dioxins and Furans Contaminated Soils

Chemical analyses are inadequate for assessing soil biological quality. Instead, the soil living community can be used both for monitoring and restoring soil health. The aim of this research was to verify vermiremediation efficiency in PCDD/F and PCB contaminated soils from Brescia-Caffaro (Italy), using an ecotoxicity approach. To gauge whether Caffaro soil could sustain a living community, a characterization of the arthropod community was conducted. Earthworms’ suitability for soil bioremediation was assessed applying ecotoxicity tests. Five treatments were set up: 1) contaminated soil; 2) contaminated soil + Eisenia fetida; 3) contaminated soil + Lepidium sativum; 4) contaminated soil + E. fetida + L. sativum, 5) uncontaminated soil + E. fetida. The ecotoxicity tests were: L. sativum germination index and root elongation inhibition, and Folsomia candida survival and reproduction, applied on soil and elutriate on: starter soil (T0), after 56 and 112 days (T56 and T112), the last after water percolation. Soil arthropod community was dominated by Hypogastruridae, Oribatida and, to a lesser degree, Formicidae and Coleoptera larvae. Ecotoxicity tests showed that F. candida reproduction and L. sativum root elongation were more adversely affected by pollutants than survival and germination. The higher soil ecotoxicity at T112 than at T56, suggested higher contaminant bioavailability after water addition. F. candida showed more variability between soil and elutriate than L. sativum. Both bioassays suggested earthworm treatment as the most promising. The importance of selecting different organisms in soil ecotoxicity monitoring, and the role of elutriate like a solid phase complement, was highlighted

Natural surface hydrocarbons and soil faunal biodiversity: A bioremediation perspective

Hydrocarbon pollution threatens aquatic and terrestrial ecosystems globally, but soil fauna in oil-polluted soils has been insufficiently studied. In this research, soil hydrocarbon toxicity was investigated in two natural oil seepage soils in Val D'Agri (Italy) using two different approaches: (i) toxicological tests with Folsomia candida (Collembola) and Eisenia fetida (Oligochaeta) and (ii) analysis of abundance and composition of micro- and meso-fauna. Soil sampling was done along 20 m-transepts starting from the natural oil seepages. Toxicological testing revealed that no exemplars of F. candida survived, whereas specimens of E. fetida not only survived but also increased in weight in soils with higher PAH concentrations, although no reproduction was observed. Analysis on microfauna showed that Nematoda was the most abundant group, with distance from seepages not affecting its abundance. Arthropoda results showed that Acarina, Collembola and Diptera larvae represented the most abundant taxa. The highest divergence in community composition was found between soils situated near seepages and at 5 m and 10 m distance. Arthropoda taxa numbers, total abundance and Acarina were lower in soils with high PAH concentration, while Diptera larvae were not significantly affected. Earthworms, together with Nematoda and Diptera larvae, could therefore represent ideal candidates in PAH degradation studies

Soil arthropod responses in agroecosystem: Implications of different management and cropping systems

The EU's Common Agricultural Policy (CAP 2014-2020) on soil management points to the combination of sustainable food production with environmental protection, reduction of CO2 emissions, and safeguarding of soil biodiversity. In this study, three farms (in the Emilia-Romagna region), managed with both conventional and conservation practices (the last ones with and without sub-irrigation systems), were monitored from 2014 to 2017 to highlight the impact of different crops and soil managements on soil arthropods, in terms of abundance, composition, and soil biological quality (applying QBS-ar index). To do this, linear mixed models were performed, whereas arthropods assemblages were studied through PERMANOVA and SIMPER analysis. Soil communities varied among farms, although most differences were found among crops depending on management practices. Nonetheless, conservation systems and a wider reduction in anthropogenic practices provided better conditions for soil fauna, enhancing QBS-ar. Moreover, arthropod groups responded to soil practices differently, highlighting their sensitivity to agricultural management. Community assemblages in corn and wheat differed between managements, mainly due to Acari and Collembola, respectively. In conservation management, wheat showed the overall greatest abundance of arthropods, owing to the great number of Acari, Collembola, and Hymenoptera, while the number of arthropod groups were generally higher in crop residues of forage

Effects of livestock pressure and vegetation cover on the spatial and temporal structure of soil microarthropod communities in Iberian rangelands

Forests, including their soils, play an important role since they represent a large reservoir of biodiversity. Current studies show that the diversity of soil fauna provides multiple ecosystem functions and services across biomes. However, anthropogenic practices often pose a threat to soil fauna because of changes in land use and soil mismanagement. In these terms, rangelands in the southwest of Spain present several problems of soil degradation related to livestock activity and soil erosion, the intensity of which compromises the soil fauna's functions in the ecosystem. Therefore, the aim of this study is to evaluate the response of community metrics and the spatial distribution of soil microarthropods to livestock activity and vegetation in such ecosystems. A photo interpretation analysis of an experimental catchment used as a study area was developed to identify and classify the intensity of livestock pressure. A total of 150 soil samples were collected throughout 2018. Soil biological (CO2 efflux) and physical-chemical parameters (pH, bulk density, organic matter, and water contents), and such meteorological variables as precipitation, temperature, and evapotranspiration were considered as variables affecting the composition of microarthropod communities in terms of taxa diversity, abundances, and their adaptation to soil environment (evaluated by QBS-ar index). Results showed higher abundance of microarthropods and higher adaptation to soil environment outside the influence of trees rather than beneath tree canopies. Moreover, the classification of livestock pressure revealed by the photo interpretation analysis showed low correlations with community structure, as well as with the occurrence of well-adapted microarthropod groups that were found less frequently in areas with evidence of intense livestock activity. Furthermore, abundances and adaptations followed different spatial patterns. Due to future climate changes and increasing anthropogenic pressure, it is necessary to continue the study of soil fauna communities to determine their degree of sensitivity to such changes

Pixantrone can be activated by formaldehyde to generate a potent DNA adduct forming agent

Mitoxantrone is an anti-cancer agent used in the treatment of breast and prostate cancers. It is classified as a topoisomerase II poison, however can also be activated by formaldehyde to generate drug–DNA adducts. Despite identification of this novel form of mitoxantrone–DNA interaction, excessively high, biologically irrelevant drug concentrations are necessary to generate adducts. A search for mitoxantrone analogues that could potentially undergo this reaction with DNA more efficiently identified Pixantrone as an ideal candidate. An in vitro crosslinking assay demonstrated that Pixantrone is efficiently activated by formaldehyde to generate covalent drug–DNA adducts capable of stabilizing double-stranded DNA in denaturing conditions. Pixantrone–DNA adduct formation is both concentration and time dependent and the reaction exhibits an absolute requirement for formaldehyde. In a direct comparison with mitoxantrone–DNA adduct formation, Pixantrone exhibited a 10- to 100-fold greater propensity to generate adducts at equimolar formaldehyde and drug concentrations. Pixantrone–DNA adducts are thermally and temporally labile, yet they exhibit a greater thermal midpoint temperature and an extended half-life at 37°C when compared to mitoxantrone–DNA adducts. Unlike mitoxantrone, this enhanced stability, coupled with a greater propensity to form covalent drug–DNA adducts, may endow formaldehyde-activated Pixantrone with the attributes required for Pixantrone–DNA adducts to be biologically active

Soil communities: who responds and how quickly to a change in agricultural system?

The use of conservation and sustainable practices could restore the abundance and richness of soil organisms in agroecosystems. Fitting in this context, this study aimed to highlight whether and how different soil living communities reacted to the conversion from an integrated to an organic orchard. The metataxonomic approach for fungi and bacteria and the determination of biological forms of diatoms and microarthropods were applied. Soil analyses were carried out in order to evaluate the effect of soil chemical features on four major soil living communities. Our results showed that the different taxa reacted with different speeds to the management changes. Fungi responded quickly to the changes, suggesting that modification in agricultural practices had a greater impact on fungal communities. Bacteria and microarthropods were more affected by abiotic parameters and less by the management. The diatom composition seemed to be affected by seasonality but the highest H’ (Shannon index) value was measured in the organic system. Fungi, but also diatoms, seemed to be promising for monitoring changes in the soil since they were sensitive to both the soil features and the anthropic impact. Our study showed that soil biodiversity could be affected by the conversion to sustainable management practices from the early years of an orchard onwards. Therefore, better ecological orchard management may strengthen soil sustainability and resilience in historically agricultural region

Soil communities: Who responds and how quickly to a change in agricultural system?

The use of conservation and sustainable practices could restore the abundance and richness of soil organisms in agroecosystems. Fitting in this context, this study aimed to highlight whether and how different soil living communities reacted to the conversion from an integrated to an organic orchard. The metataxonomic approach for fungi and bacteria and the determination of biological forms of diatoms and microarthropods were applied. Soil analyses were carried out in order to evaluate the effect of soil chemical features on four major soil living communities. Our results showed that the different taxa reacted with different speeds to the management changes. Fungi responded quickly to the changes, suggesting that modification in agricultural practices had a greater impact on fungal communities. Bacteria and microarthropods were more affected by abiotic parameters and less by the management. The diatom composition seemed to be affected by seasonality but the highest H’ (Shannon index) value was measured in the organic system. Fungi, but also diatoms, seemed to be promising for monitoring changes in the soil since they were sensitive to both the soil features and the anthropic impact. Our study showed that soil biodiversity could be affected by the conversion to sustainable management practices from the early years of an orchard onwards. Therefore, better ecological orchard management may strengthen soil sustainability and resilience in historically agricultural regions

Lightweight Model for Session-Based Recommender Systems with Seasonality Information in the Fashion Domain

This paper presents the solution designed by the team "Boston Team Party"for the ACM RecSys Challenge 2022. The competition was organized by Dressipi and was framed under the session-based fashion recommendations domain. Particularly, the task was to predict the purchased item at the end of each anonymous session. Our proposed two-stage solution is effective, lightweight, and scalable. First, it leverages the expertise of several strong recommendation models to produce a pool of candidate items. Then, a Gradient-Boosting Decision Tree model aggregates these candidates alongside several hand-crafted features to produce the final ranking. Our model achieved a score of 0.18800 in the public leaderboard. To aid in the reproducibility of our findings, we open-source our materials

Agronomical valorization of eluates from the industrial production of microorganisms: Chemical, microbiological, and ecotoxicological assessment of a novel putative biostimulant

Plant Biostimulants (BSs) are a valid supplement to be considered for the integration of conventional fertilization practices. Research in the BS field keeps providing alternative products of various origin, which can be employed in organic and conventional agriculture. In this study, we investigated the biostimulant activity of the eluate obtained as a by-product from the industrial production of lactic acid bacteria on bare agricultural soil. Eluates utilization is in line with the circular economy principle, creating economical value for an industrial waste product. The research focused on the study of physical, chemical, biochemical, and microbiological changes occurring in agricultural soil treated with the biowaste eluate, applied at three different dosages. The final aim was to demonstrate if, and to what extent, the application of the eluate improved soil quality parameters and enhanced the presence of beneficial soil-borne microbial communities. Results indicate that a single application at the two lower dosages does not have a pronounced effect on the soil chemical parameters tested, and neither on the biochemical proprieties. Only the higher dosage applied reported an improvement in the enzymatic activities of β-glucosidase and urease and in the chemical composition, showing a higher content of total, nitric and ammonia N, total K, and higher humification rate. On the other hand, microbial communities were strongly influenced at all dosages, showing a decrease in the bacterial biodiversity and an increase in the fungal biodiversity. Bioinformatic analysis revealed that some Operative Taxonomic Units (OTUs) promoted by the eluate application, belong to known plant growth promoting microbes. Some other OTUs, negatively influenced were attributed to known plant pathogens, mainly Fusarium spp. Finally, the ecotoxicological parameters were also determined and allowed to establish that no toxic effect occurred upon eluate applications onto soil