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The Putative Involvement of Bacterial Symbionts in Cantharidin Biogenesis: An Explorative Study in Meloidae Insects
No full textInsect-microbes holobionts integrate host and microbial functions, with symbionts supporting nutrition, immunity, and defence, while producing metabolites, including beetle-derived compounds with therapeutic potential. Cantharidin is a toxic terpene produced by blister beetles (Coleoptera: Meloidae), endowed with defensive and pharmacological properties. Male insects produce and contain cantharidin in large quantities and transfer it to females upon mating. This study is aimed to gain information about the involvement of insect-associated bacteria in cantharidin biogenesis. To support the possibility that bacteria participate in cantharidin biogenesis, cantharidin antibacterial activity was assessed against six reference strains of representative species of Bacillota and Pseudomonadota from publicly available culture collections. All bacterial strains tolerated concentrations up to 600 μg/ml cantharidin in a standard antibacterial susceptibility test. To identify candidate bacterial lineages, 16S rRNA metataxonomic profiling of the V5–V6 region was performed in males and females from different Meloidae subfamilies and tribes. Analysis of the insect-associated microbiomes of the five cantharidin-producing species (Lydus trimaculatus, Meloe proscarabaeus, Mylabris variabilis, Hycleus polymorphus, Zonitis flava) revealed communities dominated by Pseudomonadota, with secondary contributions from Actinomycetota in Z. flava and M. proscarabaeus and Cyanobacteriota in the other host insects. Although overall community structure and composition did not differ significantly between sexes, a few taxa displayed consistent male-associated patterns, with Staphylococcus, Cutibacterium and one Enterobacteriaceae ASV resulting more abundant in males across all species. The intrinsic bacterial resistance to cantharidin, with both quantitative and qualitative differences in microbiome structure between male and female insects, makes the hypothesis of a putative involvement of bacteria in cantharidin biogenesis still viable
Environmental and elevational drivers of diatom diversity in alpine temporary ponds
No full textHigh-elevation temporary ponds (TPs) represent habitats of high ecological value, yet they are particularly vulnerable to ongoing climate change. Diatoms are excellent bioindicators, useful for detecting ecological shifts driven by natural fluctuations or anthropogenic impacts. This study investigates whether differences in the floristic composition, measured as diversity and uniqueness (i.e., the proportion of taxa occurring exclusively in one pond), of diatom communities at small spatial scales among alpine TPs (Central Apennines, Italy) are mainly driven by isolation, elevation, or environmental factors. We found that diatom diversity in alpine biomes primarily responds to local geographical gradients, which tend to obscure any detectable effects of environmental variables. Elevation plays a key role in shaping the uniqueness of diatom communities in TPs, as higher ponds host a greater proportion of exclusive taxa. Our results indicate that local environmental conditions associated with elevation override the effects of isolation (distance between ponds), leading to the development of functionally distinct diatom communities at higher altitudes. The diversity and uniqueness of diatom assemblages are influenced by a combination of geographic and, to a lesser extent, environmental factors, with elevation acting as a central driver, both enriching diversity and promoting floristically unique communities, especially in interaction with other variables. Furthermore, electrical conductivity appears to favour communities composed of similarly adapted species, likely reflecting specific ecological conditions or adaptive responses to environmental gradients. These findings highlight the importance of elevation and spatial gradients in shaping diatom community patterns in high-altitude ephemeral freshwater habitats
Bioetica. Breve lessico ragionato
No full textIn un’epoca in cui le frontiere della biomedicina si spingono sempre più avanti, ridefinendo i confini tra vita umana e tecnica, appare sempre più necessaria una bussola per orientarsi nella complessità concettuale del nostro tempo. Organizzato in forma di dizionario tematico, il volume affronta in termini essenziali questioni cruciali — dall’aborto alla clonazione, dall’eutanasia al consenso informato, dalle cure palliative alla maternità surrogata — restituendo alla riflessione bioetica la sua funzione originaria: interrogare il senso dell’umano di fronte al potere della scienza. L’autrice propone una bioetica “senza aggettivi”, lontana dalle contrapposizioni ideologiche e attenta al bene oggettivo della persona, nella convinzione che l’etica della vita non possa essere separata dall’etica della cura. Un lessico pensato non solo per studiosi e professionisti della salute, ma anche per chiunque voglia comprendere come la medicina, la tecnica e la responsabilità morale si intreccino nel destino dell’uomo contemporaneo
Growth Mechanism of Tooeleite-like Minerals, a Potential Mineral Sink for As(III)
No full textDeveloping a strategy to trap As3+ within naturally occurring minerals is promising for water decontamination. Contextually, tooeleite, a mineral containing As3+ and Fe3+ in a sulfate medium, could be a suitable candidate. But, tooeleite is typically known to form at high concentrations of both Fe3+ and As3+ in strongly acidic pH (similar to 2.5) (acid mine drainage (AMD)-like conditions), which reduced its applicability to this narrow regime only. Herein, the nucleation and growth of tooeleite mineral has been probed at the molecular level, which follows the nonclassical nucleation pathway, deviating from classical nucleation theory. Importantly, contrary to the above-mentioned narrow regime, primary FeAsS clusters of an average diameter of 0.78 nm, nearly identical to tooeleite locally, have been found within a wide range of Fe/As solutions in situ, even at much lower concentrations (10 ppm of Fe concentration, Fe3+/As3+ = 1.5) and higher pH (pH similar to 6), where bulk tooeleite formation is unexpected. Furthermore, when subjected to AMD-like conditions, these extracted clusters readily convert into an extended tooeleite-like bulk crystalline phase. This observation that tooeleite-like clusters can originate and remain stable under conditions like >= 10 ppm Fe, Fe3+/As3+ = 1.5, and pH similar to 2 to 6 naturally opens up the possibility of mineralization as a permanent removal technique for As3+ from contaminated water
Mutamenti demografici e mutamenti giuridici. Verso un diritto degli anziani.
No full textIl Volume raccoglie i risultati delle ricerche condotte nell’ambito del Progetto PRIN 2022, Demographic and legal changes. Towards an elder law, che ha visto coinvolti studiose e studiosi delle Università di Bari, Padova, Roma Tre e Insubria nell’analisi dei profili giuridici dell’invecchiamento della popolazione. Il filo conduttore del Volume è che i mutamenti demografici, in generale, e l’invecchiamento della popolazione, in particolare, necessitino di risposte in termini giuridici. Il tema della condizione giuridica dell’anziano nel diritto contemporaneo è affrontato da diverse prospettive – dal diritto contrattuale alla tutela del consumatore, dalla responsabilità civile al diritto successorio – evidenziando le lacune del diritto esistente e proponendo soluzioni regolatorie o interpretative capaci di offrire protezione effettiva senza comprimere l’autonomia e l’autodeterminazione dell’anziano
“You Remember to Excavate; You Excavate to Remember:” Women Poets Exposing the Shortcomings of the South African Archive
No full textThis paper investigates the intersections of race, class, and gender in women’s voices and/or in historical characters from a selected corpus of English and Afrikaans poems from South Africa. The discussed authors include Makhosazana Xaba, Koleka Putuma, Phillippa Yaa de Villiers, Malika Ndlovu, Yvette Christiansë, Ronelda Kamfer, Jolyn Phillips, and Lynthia Julius. The article will specifically examine how black and coloured women’s poetry often focuses on historical female figures, either ignored or marginalised in the official records. By unearthing forgotten women and their life stories, the poets we examine contribute to illuminating the complex experiences of South African black and coloured women from different periods. The theoretical approaches that have supported us in this journey include recent views on the concept of intersectionality, such as the current reflections on the dynamics of assemblage (Bogic 2017), critical approaches to South African feminism and literature, like Barbara Boswell’s And Wrote My Story Anyway (2020), and insights on the controversial political and cultural archives of South Africa, as put forward by Verne Harris (2021). This analysis will focus on how the selected poems contest the dominant versions of history and the official archive’s lack of inclusiveness
Fede e castigo. «Confessio fidei» e «custodia urbis» nella Roma della metà del II secolo
No full textThis article reassesses Justin Martyr’s account of the executions ordered by the praefectus urbi Quintus Lollius Urbicus in mid-second-century Rome. Rather than viewing Urbicus’ actions as arbitrary persecution of the nomen Christianum, the study argues that his intervention can be understood within the broader framework of the urban prefect’s police powers and his duty to preserve the securitas Urbis. By contextualizing Justin’s narrative—also in light of Irenaeus’ polemic against the Valentinians—the article highlights how early Christian activities, especially private gatherings and perceived disruptions of household order, could be interpreted as socially destabilizing or akin to illicit collegia. This perspective provides a more nuanced understanding of the legal dynamics underlying one of the earliest documented Roman proceedings against Christians
The second syzygy schemes of curves of large degree
No full textThe present paper is a natural continuation of the previous work [2] where we studied the second syzygy scheme of canonical curves. We find sufficient conditions ensuring that the second syzygy scheme of a genus– g curve of degree at least 2g+2 coincides with the curve. If the property (N2) is satisfied, the equality is ensured by a more general fact emphasized in [2] . If (N2) fails, then the analysis uses the known case of canonical curves