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Forest soils harbour a vast array of organisms that govern the processing of organic matter. Through their trophic interactions, they give rise to carbon flows that sustain soil ecosystem functioning. Understanding how soil food webs shape carbon flows may enhance our knowledge about the role of biodiversity on soil processes. In this work, we assembled trophic networks representing soil food webs of two beech forests during spring and autumn, and compiled mass-balanced models quantifying carbon flows between their components. These models were investigated using network analysis to identify the role of the components on carbon flow, cycling and functional trophic relationships. Moreover, we explored how the structure of carbon exchanges promote efficiency and stability. Results indicate the importance of indirect interactions. Most trophic groups exhibit a diffuse dependency on all the compartments for their carbon requirement although certain groups such as Collembola play the role of hubs in distributing carbon. Indirect interactions often reverse the impacts of direct trophic relationships being antagonistic to the direction of change predicted based on predator–prey interactions. The high incidence of generalist feeding habits increases the redundancy of energy channels thereby making such food webs more resilient against perturbations but at the expense of carbon transfer efficiency. Although differences can be observed across sites and periods, food web structure rather than environmental variability seems to be the main factor responsible for patterns of carbon flows in the two beech forests. Read the free Plain Language Summary for this article on the Journal blog.

Rapidly evolving influenza A viruses (IAVs) and influenza B viruses (IBVs) are major causes of recurrent lower respiratory tract infections. Current influenza vaccines elicit antibodies predominantly to the highly variable head region of haemagglutinin and their effectiveness is limited by viral drift1 and suboptimal immune responses2. Here we describe a neuraminidase-targeting monoclonal antibody, FNI9, that potently inhibits the enzymatic activity of all group 1 and group 2 IAVs, as well as Victoria/2/87-like, Yamagata/16/88-like and ancestral IBVs. FNI9 broadly neutralizes seasonal IAVs and IBVs, including the immune-evading H3N2 strains bearing an N-glycan at position 245, and shows synergistic activity when combined with anti-haemagglutinin stem-directed antibodies. Structural analysis reveals that D107 in the FNI9 heavy chain complementarity-determinant region 3 mimics the interaction of the sialic acid carboxyl group with the three highly conserved arginine residues (R118, R292 and R371) of the neuraminidase catalytic site. FNI9 demonstrates potent prophylactic activity against lethal IAV and IBV infections in mice. The unprecedented breadth and potency of the FNI9 monoclonal antibody supports its development for the prevention of influenza illness by seasonal and pandemic viruses.

he present study investigates the use of Discourse Markers (DMs) in the context of Italian migration varieties using an onomasiological approach, i.e. looking at the functions that DMs entail in conversation. Thus, this study focuses on intergenerational variation, namely, how the use of DMs in terms of their functional space varies across generations. We will consider only the metadiscoursive functions, i.e. all the microfunctions aiming at structuring the discourse, ensuring clarity and affecting the organization of discourse. They are analysed in two generations of Italian migrants living in Munich. Data are taken from a corpus of audio recorded interview with 13 Italian migrants living in Munich (average length of each interview, 30 minutes). Results point out that the second-generation informants DMs undergo both a gradual loss of types and a gradual reduction of tokens.

The paper presents a brief review of research in the field of L2/LS pragmatic teaching, focusing on the effects of explicit versus implicit approach in learning situations that focus on discourse markers (DMs). The literature on the subject offers a vast panorama of studies that take into consideration different types of structuring of the didactic intervention. Although studies on the development of DMs have shown that input flood and frequent exposure to specific target forms support their acquisition, explicit instruction along with input flood has been shown to positively influence the overall frequency and use of DMs.

The aim of this research was to highlight the impact of urbanization and agriculture on soil quality, mainly by focusing on heavy metal accumulation (Cd, Cu, Fe, Mn, Ni, Pb and Zn) in the fragile riparian ecosystems of the Medjerda river (Souk-Ahras, Algeria). This study was performed in three cultivated soils (0-10, 10-20, 20-60 cm depth) along an increasing gradient of anthropogenic pressure in non-urban (NU), peri-urban (PU) and urban areas (U). Geo-accumulation index (Igeo), Enrichment factor (EF), Pollution load index (PLI) and Potential ecological risk index (RI) were calculated, as well as the potential non-carcinogenic risk for humans (HI). Additionally, to corroborate the role of Bufo spinosus D. as biosentinel, a skin biopsy was performed to quantify the concentration of heavy metals in both terrestrial and aquatic ecosystems. The results showed that when compared to NU, U and PU areas were richer in heavy metals. In particular, Igeo-Cd displayed strongly contaminated soil in U (> 3), EF showed high enrichment of heavy metals (> 2) for all the soils except for Ni, PLI presented no contamination for all (< 1) while RI was significantly higher in U (> 300), denoting a strong impact of heavy metals on soil quality. However, HI was below 1 for all the studied areas, although the highest values were related to U and PU. The skin biopsy showed the highest values for Cu, Fe and Pb in PU (0.328, 0.713 and 0.524 mg kg-1, respectively) similarly to trends observed in the soil of that area. This study shed light on the rising pollution of heavy metals due to urbanization and agricultural input in these fragile ecosystems where Bufo spinosus D. plays the role of potential bio-indicator for environmental pollution.

The combined action of alien plants invasion and fire occurrence can strongly alter local biodiversity and soil functions especially in the Mediterranean area. In this context, the goal of the study was to assess the effects of the invasive black locust (Robinia pseudoacacia L.) spread on soil characteristics, especially soil microbial community responses, in some Mediterranean shrublands and pine forests subjected to both a slow natural invasion and a fast fire-induced invasion. The soil sampled in all stands, regardless type of black locust invasion, showed increasing values of pH, water holding capacity and bulk density as compared to soil of pure shrublands and pine forests. Soil organic matter content approximately doubled in stands invaded by black locust trees (from 4.3 and 9.0 % in shrublands and from 5.3 and 14.5 % in pine forests after fire respectively). A similar trend was observed for the soil nitrogen content with values of 2.9 and 8.2 mg g−1 in pure and invaded shrublands after fire respectively and values of 3.8 and 5.4 mg g−1 in pure and invaded pine after fire. Moreover, the combined effect of black locust invasion and fire occurrence improved soil content and availability of the investigated elements (Ca, Cu, Fe, K, Mg, Mn, Na). In addition, the invasion seemed to stimulate microbial growth, by promoting especially the bacterial component regardless of the plant cover and fire occurrence. A significant decrease of microbial respiration was observed only in invaded pine forests (0.18 mg CO2 g−1 d-1) as compared to pure forests (0.32 mg CO2 g−1 d-1). On the other hand, in all invaded shrublands a reduced efficiency of carbon resource utilisation and a high stress condition of the microbial community were evident. However, the combined impact of black locust invasion and fire occurrence does not show specific changes in the investigated stands. Fire confirms and, sometimes, promotes the changes due to the spread of black locust in both shrublands and pine forests soils.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages carry distinct spike mutations resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters elicit plasma-neutralizing antibodies against Omicron BA.1, BA.2, BA.2.12.1, and BA.4/5, and that breakthrough infections, but not vaccination alone, induce neutralizing antibodies in the nasal mucosa. Consistent with immunological imprinting, most antibodies derived from memory B cells or plasma cells of Omicron breakthrough cases cross-react with the Wuhan-Hu-1, BA.1, BA.2, and BA.4/5 receptor-binding domains, whereas Omicron primary infections elicit B cells of narrow specificity up to 6 months after infection. Although most clinical antibodies have reduced neutralization of Omicron, we identified an ultrapotent pan-variant-neutralizing antibody that is a strong candidate for clinical development. ispartof: SCIENCE vol:378 issue:6620 pages:619-+ ispartof: location:United States status: published

SARS-CoV-2 from alpha to epsilon As battles to contain the COVID-19 pandemic continue, attention is focused on emerging variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that have been deemed variants of concern because they are resistant to antibodies elicited by infection or vaccination or they increase transmissibility or disease severity. Three papers used functional and structural studies to explore how mutations in the viral spike protein affect its ability to infect host cells and to evade host immunity. Gobeil et al . looked at a variant spike protein involved in transmission between minks and humans, as well as the B1.1.7 (alpha), B.1.351 (beta), and P1 (gamma) spike variants; Cai et al . focused on the alpha and beta variants; and McCallum et al . discuss the properties of the spike protein from the B1.1.427/B.1.429 (epsilon) variant. Together, these papers show a balance among mutations that enhance stability, those that increase binding to the human receptor ACE2, and those that confer resistance to neutralizing antibodies. —VV

Secondary metabolites extracted from plants have historically been critical for drug discovery, but their isolation involves expensive and complicated procedures in terms of time and labor resources. Thus, the biogenetic pathway offers the possibility of identifying specific compounds that have not yet been isolated and predicting their isolation from specific natural sources. In plants, biphenanthrenes represent a relatively small group of aromatic secondary metabolites that are considered as important taxonomic markers with promising biological activities. To date, 38 mixed phenanthrenoid dimers have been identified, the biosynthesis of which involves the radical coupling of the two subunits, namely, a phenanthrene and a dihydrophenanthrene. For each of the compounds, it is possible to identify the single phenanthrenic and dihydrophenanthrenic units constituting the considered dimer. Based on the biogenetic pathway, it is possible to identify 19 phenanthrenes and 17 dihydrophenanthrenes, and to distinguish those already known from those not yet isolated. By comparing the results of the possible biosynthetic pathway for each compound with the data in the literature, it is possible to identify three known phenanthrenes and seven known dihydrophenanthrenes, as well as eleven new phenanthrenes and five new dihydrophenanthrenes, and to identify from which plant it is possible to isolate them. This could direct the work of researchers seeking to identify known or new molecules useful for their possible biological properties, and ultimately, to confirm the veracity of the proposed and generally accepted biosynthetic pathway.

The present paper deals with the acquisition of discourse markers (DMs) in L2 Italian in two different groups of learners and focuses on the methodological problems of comparing interlanguage corpora produced in immersion and non-immersion contexts. The learners are Spanish speakers with an A2 level in Italian and the corpus has been collected in two different settings: a full-immersion context at the University of Calabria in Italy and a guided-learning context at two language schools in Spain. The research focuses on the acquisition of interactional discourse markers and their role in the dynamics of conversations both between non-native speakers and between native and non-native speakers. We analyse the most frequent interactional functions conveyed by DMs, the types employed by native speakers and learners in each of these functions and their frequency. Our results show how acquisition in immersion and non-immersion contexts differs not in the variety of interactional functions displayed by non-native speakers but in the higher number of types of discourse markers employed, and presents the advantages and drawbacks of learning processes in both types of contexts regarding pragmatic strategies.

Gymnema sylvestre is a commonly used herb in Ayurvedic medicine. The demand for its extracts in the commercial and pharmaceutical fields has been steadily increasing in recent years. Its extracts are used to treat various ailments as well as for their antimicrobial properties. This study has evaluated the antimicrobial effects of different G. sylvestre extracts and of eight triterpenes isolated from the most active extract on six bacterial poultry pathogens i.e. Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterobacter aerogenes. In particular, it has been evaluated the minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of all extracts and isolated triterpenes. Finally, the cytotoxicity activity of triterpenes was evaluated by MTT assay and their antioxidant activity in basal and oxidant conditions by DCFH-DA assay.

Understanding broadly neutralizing sarbecovirus antibody responses is key to developing countermeasures against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and future zoonotic sarbecoviruses. We describe the isolation and characterization of a human monoclonal antibody, designated S2K146, that broadly neutralizes viruses belonging to SARS-CoV– and SARS-CoV-2–related sarbecovirus clades, which use angiotensin-converting enzyme 2 (ACE2) as an entry receptor. Structural and functional studies show that most of the virus residues that directly bind S2K146 are also involved in binding to ACE2. This allows the antibody to potently inhibit receptor attachment. S2K146 protects against SARS-CoV-2 Beta variant challenge in hamsters, and viral passaging experiments reveal a high barrier for emergence of escape mutants, making it a good candidate for clinical development. The conserved ACE2-binding residues present a site of vulnerability that might be leveraged for developing vaccines eliciting broad sarbecovirus immunity.

The knowledge of the effects of fire on soil properties is of particular concern in Mediterranean areas, where the effects of vegetation type are still scarce also. This research aimed: to assess the properties of burnt soils under different vegetation types; to highlight the soil abiotic properties driving the soil microbial biomass and activity under each vegetation type; to compare the biological response in unburnt and burnt soils under the same vegetation type, and between unburnt and burnt soils under different vegetation types. The soils were collected at a Mediterranean area where a large wildfire caused a 50% loss of the previous vegetation types (holm oak: HO, pine: P, black locust: BL, and herbs: H), and were characterized by abiotic (pH, water, and organic matter contents; N concentrations; and C/N ratios) and biotic (microbial and fungal biomasses, microbial respiration, soil metabolic quotient, and hydrolase and dehydrogenase activities) properties. The biological response was evaluated by the Integrative Biological Responses (IBR) index. Before the fire, organic matter and N contents were significantly higher in P than H soils. After the fire, significant increases of pH, organic matter, C/N ratio, microbial biomass and respiration, and hydrolase and dehydrogenase activities were observed in all the soils, especially under HO. In conclusion, the post-fire soil conditions were less favorable for microorganisms, as the IBR index decreased when compared to the pre-fire conditions.

To date, just over a hundred phenanthrenoid dimers have been isolated. Of these, forty-two are completely phenanthrenic in nature. They are isolated from fourteen genera of different plants belonging to only five families, of which Orchidaceae is the most abundant source. Other nine completely acetylated and five methylated dimers were also defined, which were effective in establishing the position of the free hydroxyls of the corresponding natural products, from which they were obtained by semi-synthesis. Structurally, they could be useful chemotaxonomic markers considering that some substituents are typical of a single-family, such as the vinyl group for Juncaceae. From a biogenetic point of view, it is thought that these compounds derive from the radical coupling of the corresponding phenanthrenes or by dehydrogenation of the dihydrophenanthrenoid analogs. Phenanthrenes or dihydroderivatives possess different biological activities, e.g., antiproliferative, antimicrobial, antiinflammatory, antioxidant, spasmolytic, anxiolytic, and antialgal effects. The aim of this review is to summarize the occurrence of phenanthrene dimers in the different natural sources and give a comprehensive overview of their structural characteristics and biological activities.

This research explores the effects of explicit instruction on the use of discourse markers (DMs) by international students of Italian as a second language (L2). 30 students of various nationalities with A2-B1 proficiency level participated in the study: 15 students represented the experimental group and 15 students the control group. Both groups were given a written pre-test and a post-test consisting both of a story telling completion task and a dialogue completion task. The instruction consisted of some detailed informations about the use and function of DMs as well as the exposure to native-models use of DMs. The students of the control group were exposed to the input flood and were encouraged to notice the DMs but they were not presented with the detailed description of DMs and were not engaged in any communicative practice other than drills and cloze tests. The Italian markers beh (‘well’), magari (‘maybe’), insomma (‘in short’), quindi (‘then’, ‘so’) were the focus of the instruction. The results of the study point to the differences between the two groups. The experimental group showed a greater range of pragmatic functions (inter-actional, metadiscoursive and cognitive) associated with the DMs than the control group. Indeed, the learners of the control group showed no improvement in terms of frequency and variety of DMs.

The control of the aggregation of biomedical nanoparticles (NP) in physiological conditions is crucial as clustering may change completely the way they interact with the biological environment. Here we show that Au nanoparticles, functionalized by an anionic, amphiphilic shell, spontaneously aggregate in fluid zwitterionic lipid bilayers. We use Molecular Dynamics and enhanced sampling techniques to disentangle the short-range and long-range driving forces of aggregation. At short inter-particle distances, ion-mediated, charge-charge interactions (ion bridging) stabilize the formation of large NP aggregates, as confirmed by cryo-electron microscopy. Lipid depletion and membrane curvature are the main membrane deformations driving long-range NP-NP attraction. Ion bridging, lipid depletion, and membrane curvature stem from the configurational flexibility of the nanoparticle shell. Our simulations show, more in general, that the aggregation of same-charge membrane inclusions can be expected as a result of intrinsically nanoscale effects taking place at the NP-NP and NP-bilayer soft interfaces.

Soil biological properties and carbon storage of three young Technosols deriving from volcanic soil of Campi Flegrei, Italy, were compared with two natural volcanic soils, sampled from two forest ecosystem sites (chestnut and Mediterranean maquis). The soil properties were examined with Vis-NIR spectroscopy and portable XRF, along the soil profile. The results showed that the average soil organic matter (SOM) amount in Technosols profiles were lower than in natural volcanic soils. The differences in SOM content between the two investigated natural volcanic soils probably resulted from their land-use histories and different plant cover. Indeed, the chestnut soil profile, which has a higher SOM content, was covered by an old chestnut grove, while the second soil profile, after a severe burning, showed a change in natural Oak forest vegetation towards the typical Mediterranean maquis. The microbial biomass can be predicted with Vis-NIR spectroscopy coupled with PLS Regression. Our results showed that 6-year natural incorporation of organic residue in Technosols significantly increased the C storage on the top soils due to the increase in C input with rhizodeposition. The forest soils show higher TOC content also with the depth that indicate a greater capacity of C storage in response to litter incorporation, whereas the Technosols accumulated about half the amount of TOC, compared to the chestnut grove. Indeed, after six years of natural vegetation, the Technosols showed a large potential to sequester C and to sustain biological activity. Overall, the emerging knowledge on technosols make them highly promising for the regeneration of urban area.

Climate change has strongly increased the fire frequency in Mediterranean forests causing changes in soil bacterial, fungal and microarthropod communities. Fire impacts on soil properties depend on vegetation covers. In this framework, the aim of this research was to evaluate the effects of fire on bacterial, fungal communities and microarthropod community in soils under trees and shrubs in a Mediterranean area. Surface soil cores were sampled in unburnt and burnt (three years since fire occurrence) patches in the Vesuvius National Park trees (Quercus ilex L. and Pinus nigra L.) and shrubs (Ginesta sp., Myrtus communis L., Laurus nobilis L.). Samples were analyzed for abiotic (pH, water content and concentrations of C, N, Corg, P, NO2 NH4+ and Pavail) and biotic (bacterial and fungal biomasses, and density, taxa richness, diversity, evenness and QBS-ar of microarthropods) properties. Results showed that, three years since fire, the abiotic properties were recovered in shrub stands but not yet in tree stands. Fire stimulated the development of bacteria only in shrub stands; no effects were observed for the fungal community in both shrub and tree stands; the amount and the taxa richness of microarthropods recovered to the values of the pre-fire conditions in both the stands. In conclusion, in the investigated area, fire differently impacted the vegetation covers, making soils under trees more similar to shrubs with the consequence to reduce the differences between the vegetation covers

SUMMARYThe recently emerged SARS-CoV-2 Omicron variant harbors 37 amino acid substitutions in the spike (S) protein, 15 of which are in the receptor-binding domain (RBD), thereby raising concerns about the effectiveness of available vaccines and antibody therapeutics. Here, we show that the Omicron RBD binds to human ACE2 with enhanced affinity relative to the Wuhan-Hu-1 RBD and acquires binding to mouse ACE2. Severe reductions of plasma neutralizing activity were observed against Omicron compared to the ancestral pseudovirus for vaccinated and convalescent individuals. Most (26 out of 29) receptor-binding motif (RBM)-directed monoclonal antibodies (mAbs) lost in vitro neutralizing activity against Omicron, with only three mAbs, including the ACE2-mimicking S2K146 mAb1, retaining unaltered potency. Furthermore, a fraction of broadly neutralizing sarbecovirus mAbs recognizing antigenic sites outside the RBM, including sotrovimab2, S2X2593 and S2H974, neutralized Omicron. The magnitude of Omicron-mediated immune evasion and the acquisition of binding to mouse ACE2 mark a major SARS-CoV-2 mutational shift. Broadly neutralizing sarbecovirus mAbs recognizing epitopes conserved among SARS-CoV-2 variants and other sarbecoviruses may prove key to controlling the ongoing pandemic and future zoonotic spillovers.

Mediterranean grasslands are semi-natural, fire-prone, species-rich ecosystems that have been maintained for centuries through a combination of fire, grazing, and mowing. Over the past half century, however, grasslands have faced numerous threats, including the abandonment of traditional agro-pastoral practices. Our hypothesis was that mowing and prescribed burning are management practices potentially effective in counteracting the reduction of plant diversity triggered by land abandonment. However, the long-term effects of such management practices on plant communities and soil microbiota in Mediterranean grassland remain poorly studied. Here, we conducted a 5-year field experiment comparing prescribed fire, vegetation mowing, and abandonment in a fire-prone Mediterranean grassland in southern Italy in order to evaluate the capability of such management strategies to counteract the detrimental impacts of land abandonment on plant diversity and the associated increase of wildfire. We combined vegetation analysis and soil chemical characterization and several microbiota analyses, including microbial biomass and respiration, arthropod community, and high-throughput sequencing of bacterial and eukaryotic rRNA gene markers. Burning and mowing significantly increased plant species richness and diversity compared to abandonment plots, reducing the abundance of perennial tall grasses in favour of short-lived species. Standing litter followed the same trend, being 3.8-fold greater and largely composed of grass remains in the abandoned compared to burnt and mowed plots. In the soil, prescribed burning caused significant increase in pH, a reduction in organic carbon, total N, and cation exchange capacity. Diversity and taxonomic composition of bacterial and fungal microbiota was affected by burning and mowing treatments. Abandonment caused shifts of microbiota towards a fungal-dominated system, composed of late successional fungi of the Basidiomycota. Fast-growing and putative fungal pathogens were more abundant under burnt and mowed treatments. Soil arthropods were influenced by vegetation and microbiota changes, being strongly reduced in mowed plots. Our study demonstrated that grassland abandonment promotes the spread of tall grasses, reducing plant diversity and increasing the risk of wildfire, while prescribed burning and mowing are effective in counteracting such negative effects.

Supramolecular polymers are composed of monomers that self-assemble non-covalently, generating distributions of monodimensional fibres in continuous communication with each other and with the surrounding solution. Fibres, exchanging molecular species, and external environment constitute a sole complex system, which intrinsic dynamics is hard to elucidate. Here we report coarse-grained molecular simulations that allow studying supramolecular polymers at the thermodynamic equilibrium, explicitly showing the complex nature of these systems, which are composed of exquisitely dynamic molecular entities. Detailed studies of molecular exchange provide insights into key factors controlling how assemblies communicate with each other, defining the equilibrium dynamics of the system. Using minimalistic and finer chemically relevant molecular models, we observe that a rich concerted complexity is intrinsic in such self-assembling systems. This offers a new dynamic and probabilistic (rather than structural) picture of supramolecular polymer systems, where the travelling molecular species continuously shape the assemblies that statistically emerge at the equilibrium.

Worldwide SARS-CoV-2 transmission leads to the recurrent emergence of variants, such as the recently described B.1.617.1 (kappa), B.1.617.2 (delta) and B.1.617.2+ (delta+). The B.1.617.2 (delta) variant of concern is causing a new wave of infections in many countries, mostly affecting unvaccinated individuals, and has become globally dominant. We show that these variants dampen the in vitro potency of vaccine-elicited serum neutralizing antibodies and provide a structural framework for describing the impact of individual mutations on immune evasion. Mutations in the B.1.617.1 (kappa) and B.1.617.2 (delta) spike glycoproteins abrogate recognition by several monoclonal antibodies via alteration of key antigenic sites, including an unexpected remodeling of the B.1.617.2 (delta) N-terminal domain. The binding affinity of the B.1.617.1 (kappa) and B.1.617.2 (delta) receptor-binding domain for ACE2 is comparable to the ancestral virus whereas B.1.617.2+ (delta+) exhibits markedly reduced affinity. We describe a previously uncharacterized class of N-terminal domain-directed human neutralizing monoclonal antibodies cross-reacting with several variants of concern, revealing a possible target for vaccine development.

The assessment of Technosols quality in urban environments is pivotal for the maintenance of ecosystems impacted by human activities. The study was performed on Technosols constructed in experimental mesocosms in the suburban area of Naples (Southern Italy) to highlight changes in the main soil properties over eight years and to identify the most suitable indices at quality monitoring. In this study, several chemical, biological, and integrated indices were analysed to evaluate the mineral accumulation, potential ecological risk, edaphon activity, fertility, and the overall soil quality. The Technosols showed alkaline pH, nitrogen ranged from 24.5 to 39.5 g kg−1, high organic matter contents above 40 g kg−1, and there were no evident processes of soil compaction. Heavy metals (Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn) did not exceed the thresholds defined by the Italian law for urban soils, despite their volcanic components. During eight years, the chemical indices depicted changes in the elements balance and increase in ecological risk, the biological indices indicated a reduction in the fungal fraction (fivefold) and in the resources utilisation and carbon storage. The soil quality index with all parameters highlighted the reduction in the soil quality (from 0.78 to 0.65) due to the decrease of the chemical quality, the increase of microbial stress conditions, and changes of the microbial composition, underlining the importance of integrating chemical and biological information for monitoring Technosols.

Anthropization often leads to land use transformation, causing deep changes to soil properties and its quality. Land use change could be an environmental and socioeconomic problem, as it impacts soil quality and ecosystem services. There is an urgent need to understand the pressures affecting soil quality. The aim of the work is to quantify the impact of different land uses on soil abiotic and biotic properties and on its quality. To achieve the aims, soils from different land uses (forest, urban and agricultural) were collected in the surroundings of Naples and analyzed for pH, water content, contents of C and N, C/N ratio and total and available concentrations of Cu, Ni and Pb, microbial and fungal biomasses, basal respiration and metabolic quotient. Then, a soil quality index (SQI) was calculated for each land use. The results showed that soil abiotic and biotic properties of the agricultural sites differed from those of forest and urban sites. At agricultural sites, microbial abundances decreased due to low amount of C and N and to high amount of Cu and Pb. This caused low use efficiency of energetic substrates and a reduced soil quality of agricultural sites as compared to forest and urban sites.

The recent emergence of SARS-CoV-2 variants of concern1-10 and the recurrent spillovers of coronaviruses11,12 into the human population highlight the need for broadly neutralizing antibodies that are not affected by the ongoing antigenic drift and that can prevent or treat future zoonotic infections. Here we describe a human monoclonal antibody designated S2X259, which recognizes a highly conserved cryptic epitope of the receptor-binding domain and cross-reacts with spikes from all clades of sarbecovirus. S2X259 broadly neutralizes spike-mediated cell entry of SARS-CoV-2, including variants of concern (B.1.1.7, B.1.351, P.1, and B.1.427/B.1.429), as well as a wide spectrum of human and potentially zoonotic sarbecoviruses through inhibition of angiotensin-converting enzyme 2 (ACE2) binding to the receptor-binding domain. Furthermore, deep-mutational scanning and in vitro escape selection experiments demonstrate that S2X259 possesses an escape profile that is limited to a single substitution, G504D. We show that prophylactic and therapeutic administration of S2X259 protects Syrian hamsters (Mesocricetus auratus) against challenge with the prototypic SARS-CoV-2 and the B.1.351 variant of concern, which suggests that this monoclonal antibody is a promising candidate for the prevention and treatment of emergent variants and zoonotic infections. Our data reveal a key antigenic site that is targeted by broadly neutralizing antibodies and will guide the design of vaccines that are effective against all sarbecoviruses.

An ideal therapeutic anti-SARS-CoV-2 antibody would resist viral escape1–3, have activity against diverse sarbecoviruses4–7, and be highly protective through viral neutralization8–11 and effector functions12,13. Understanding how these properties relate to each other and vary across epitopes would aid the development of therapeutic antibodies and guide vaccine design. Here we comprehensively characterize escape, breadth and potency across a panel of SARS-CoV-2 antibodies targeting the receptor-binding domain (RBD). Despite a trade-off between in vitro neutralization potency and breadth of sarbecovirus binding, we identify neutralizing antibodies with exceptional sarbecovirus breadth and a corresponding resistance to SARS-CoV-2 escape. One of these antibodies, S2H97, binds with high affinity across all sarbecovirus clades to a cryptic epitope and prophylactically protects hamsters from viral challenge. Antibodies that target the angiotensin-converting enzyme 2 (ACE2) receptor-binding motif (RBM) typically have poor breadth and are readily escaped by mutations despite high neutralization potency. Nevertheless, we also characterize a potent RBM antibody (S2E128) with breadth across sarbecoviruses related to SARS-CoV-2 and a high barrier to viral escape. These data highlight principles underlying variation in escape, breadth and potency among antibodies that target the RBD, and identify epitopes and features to prioritize for therapeutic development against the current and potential future pandemics. A survey of SARS-CoV-2 RBD antibodies identifies those with activity against diverse SARS-CoV-2 variants and SARS-related coronaviruses, highlighting epitopes and features to prioritize in antibody and vaccine development.

Recently, surface soils of remote or protected areas, that receive pollutants from the surroundings or in situ activities through dry and wet deposition, exceed the baseline content of heavy metals. In the last decades, the use of single and integrated indices is a powerful tool to process, analyze and convey information about metal accumulation degree for decision makers to better manage protected areas. Single indices provide information about only one metal, whereas the integrated ones give a holistic evaluation. The aim of the research was to assess the temporal trends of three single (Contamination Factor, Enrichment Factor and Geo-accumulation Index) and two integrated (Pollution Load Index, Nemerow index) indices in order to evaluate if the touristic impact caused soil metal (Cr, Cu, Ni and Pb) accumulation. In autumn 2016 and in spring 2016 and 2017, the surface soils (0–10 cm) were collected at eight sites inside the Vesuvius National Park (Southern Italy), characterized by intense tourism from spring to autumn. The metal concentrations were measured in the soils and used to calculate the indices. In addition, the Ecological Risk Factor was calculated and the phytotoxicological assays were performed. The findings showed that the surface soils of the Vesuvius National Park were polluted by Cr, Cu, Ni and Pb, according to both single and integrated indices. The touristic impact would seem to be the main cause of soil metal accumulation, as the highest values of the calculated indices were detected for samples collected at the end of the touristic season and the lowest at the beginning of the touristic season. Anyway, Cu and Pb would seem also to derive by ex situ anthropogenic sources, whereas Cr and Ni also by natural sources, such as spontaneous fires and substrate weathering. Finally, the soils showed phytotoxic effects and low ecological risks.

Background and aim: Litter decomposition is of great concern as it plays a key role in regulating global carbon cycle and nutrient budgets, especially in tropical forests where it is very fast. Therefore, we studied the decomposition and subsequent changes in element concentrations and amounts of 11 tropical leaf litter. Methods: Fresh litters were characterized in terms of elemental, proximate features, as well as organic carbon compositions by 13C-NMR spectroscopy. Controlled litterbag decomposition was carried out for 180 days in the laboratory, bags were retrieved at three dates and analyzed for mass loss and concentration of nitrogen (N), potassium (K), sodium (Na), carbon (C), magnesium (Mg), manganese (Mn), iron (Fe), phosphorus (P), zinc (Zn), and percentage of ash, extractives, cellulose and lignin. Results: Terminalia arjuna showed highest mass loss, while the lowest was observed in Shorea robusta showing significant positive correlation with litter initial K, Mg, Fe and di-O-alkyl C, O-alkyl C, while significant negative correlation with Mn, lignin and Methoxyl C, Alkyl C. Trajectories shows that Fe, Mg, K, Mn, Zn and Na concentrations increased in most of the litter types, except Terminalia arjuna and Toona ciliata, where Fe, Mg, K concentrations decreased during decomposition. Surprisingly, in most of the species with the exception of Terminalia arjuna, N concentrations decreased at a faster rate than C concentrations, resulting in an increase in C/N ratios. Expectedly, lignin progressively increased, while cellulose decreased. Conclusions: Observed differences in decomposition rate and dynamics of chemical changes among litters were strongly affected by the litter type, decomposition time and their interactions.

Mediterranean regions are the most impacted by fire in Europe. The effects of fire on soil greatly vary according to several factors such as vegetation cover type, but they are scarcely studied. Therefore, this research aimed at evaluating the combined impacts of fire and vegetation on single soil characteristics and on the overall soil quality and functionality through two soil quality indices, simple additive (SQI) and a weighted function (SQIFUNCT). In order to reach the aims, burnt and unburnt soils were collected under different vegetation cover types (herbs and shrubs, black locust, pine and holm oak) within the Vesuvius National Park. The soils were analyzed for the main abiotic (water and organic matter content, total C, N, Ca, K, Cu and Pb concentrations, C/N ratio) and biotic (microbial and fungal biomasses, basal respiration, β-glucosidase activity) characteristics. On the basis of the investigated soil characteristics, several soil functions (water retention, nutrient supply, contamination content, microorganism habitat and activities), and the soil quality indices were calculated. The results showed that the impact of fire on soil quality and functionality was mediated by the vegetation cover type. In fact, fire occurrence led to a decrease in water and C/N ratio under herbs, a decrease in C concentration under holm oak and a decrease in Cu and Pb concentrations under pine. Although the soil characteristics showed significant changes according to vegetation cover types and fire occurrence, both the additive and weighted function soil quality indices did not significantly vary according to both fire occurrence and the vegetation cover type. Among the different vegetation cover types, pine was the most impacted one.

This exploratory study examines strategies of refusals in two groups of peninsular and Ecuadorian Spanish learners of Italian, attending university courses in Italy. The aim of the investigation is to explore the type, the order and the frequency of refusals and the role of transfer in situations characterized by different role relationships among interactants. Data was collected using a Discourse Completion Task and a retrospective interview. Results show that Ecuadorian learners sometimes transfer their L1 patterns into the L2. Outcomes are discussed in light of studies on Politeness Theory.

SARS-CoV-2 entry is mediated by the spike (S) glycoprotein which contains the receptor-binding domain (RBD) and the N-terminal domain (NTD) as the two main targets of neutralizing antibodies (Abs). A novel variant of concern (VOC) named CAL.20C (B.1.427/B.1.429) was originally detected in California and is currently spreading throughout the US and 29 additional countries. It is unclear whether antibody responses to SARS-CoV-2 infection or to the prototypic Wuhan-1 isolate-based vaccines will be impacted by the three B.1.427/B.1.429 S mutations: S13I, W152C and L452R. Here, we assessed neutralizing Ab responses following natural infection or mRNA vaccination using pseudoviruses expressing the wildtype or the B.1.427/B.1.429 S protein. Plasma from vaccinated or convalescent individuals exhibited neutralizing titers, which were reduced 3-6 fold against the B.1.427/B.1.429 variant relative to wildtype pseudoviruses. The RBD L452R mutation reduced or abolished neutralizing activity of 14 out of 35 RBD-specific monoclonal antibodies (mAbs), including three clinical-stage mAbs. Furthermore, we observed a complete loss of B.1.427/B.1.429 neutralization for a panel of mAbs targeting the N-terminal domain due to a large structural rearrangement of the NTD antigenic supersite involving an S13I-mediated shift of the signal peptide cleavage site. These data warrant closer monitoring of signal peptide variants and their involvement in immune evasion and show that Abs directed to the NTD impose a selection pressure driving SARS-CoV-2 viral evolution through conventional and unconventional escape mechanisms.

The recent emergence of SARS-CoV-2 variants of concern (VOC) and the recurrent spillovers of coronaviruses in the human population highlight the need for broadly neutralizing antibodies that are not affected by the ongoing antigenic drift and that can prevent or treat future zoonotic infections. Here, we describe a human monoclonal antibody (mAb), designated S2×259, recognizing a highly conserved cryptic receptor-binding domain (RBD) epitope and cross-reacting with spikes from all sarbecovirus clades. S2×259 broadly neutralizes spike-mediated entry of SARS-CoV-2 including the B.1.1.7, B.1.351, P.1 and B.1.427/B.1.429 VOC, as well as a wide spectrum of human and zoonotic sarbecoviruses through inhibition of ACE2 binding to the RBD. Furthermore, deep-mutational scanning and in vitro escape selection experiments demonstrate that S2×259 possesses a remarkably high barrier to the emergence of resistance mutants. We show that prophylactic administration of S2×259 protects Syrian hamsters against challenges with the prototypic SARS-CoV-2 and the B.1.351 variant, suggesting this mAb is a promising candidate for the prevention and treatment of emergent VOC and zoonotic infections. Our data unveil a key antigenic site targeted by broadly-neutralizing antibodies and will guide the design of pan-sarbecovirus vaccines.

AimsPlant cover and microclimatic conditions can profoundly alter the balance between productivity and decay, with relevant effects on soil C and N pools. In this contest, the aim of the present study was to assess how, in Mediterranean areas, soil properties and C and N sequestration differs between afforested pine forests and natural shrublands in different microclimatic conditions at low and high elevations.MethodsThe study was performed along the soil profile distinguishing between the organic layers, fermentation and humic layers, and surface mineral soils. The comparison between plant covers and elevations were carried out for C and N pools and soluble fractions, molecular characterization by solid state 13C NMR of organic layers and by 1HNMR of soil soluble fractions, potential mineralization rates and microbial and fungal amounts.ResultsOur data confirm that coniferous tree species sequester C faster than shrubs and herbaceous species especially at low elevation under favourable microclimatic conditions. Soil C and N pools reflect changes in the chemical composition of the upper organic layers and of soil soluble organic matter. In pine forests, the higher concentration of N in the upper organic layer speeds up the N loss in the fermentative layer and stimulates humus formation and C accumulation at low elevations.ConclusionsPlant cover and microclimatic conditions drive the C sequestration rate and the soil organic matter stability. Chemical changes highlighted by nuclear magnetic resonance spectroscopy can clarify patterns of decay processes and help to make predictions in a climate change scenario.