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Fish invasion restructures freshwater food webs, facilitating new invasions over three decades
No full textAlthough biological invasions are a well-known driver of biodiversity loss in freshwaters, their impact on the structure of aquatic food webs remains relatively poorly investigated. This study examined changes in aquatic community networks driven by biological invasions in the lower Po River Basin, Italy, over the past three decades. Using network analysis of fish and macroinvertebrate communities at early (before 1991) and late (after 2009) stages of the invasion, we reveal a significant simplification of the structure of the food web, characterized by reduced species richness and fewer connections, as well as a shift from balanced community control to predominantly bottom-up forces in the late invasion stage. Environmental data showed a shift towards turbid, hypoxic conditions consistent with bioturbation and vegetation loss caused by invasive carp. Native predators such as Esox cisalpinus were replaced by tolerant nonnative invertivorous fish species and predators such as Silurus glanis, indicating trophic reorganization. Canal size influenced invasion outcomes; large canals experienced the greatest species loss, likely due to size-refuge effects reducing top-down control. Asymmetrical trophic interactions and redundancy analyses further support the dominance of bottom-up effects in late-stage communities. These findings align with the invasional meltdown hypothesis, whereby one invader facilitates others, thereby amplifying ecosystem disruption. Despite limitations in the available data, including the absence of pre-invasion baselines and estimates of basal biomass, our results emphasize the advantage of using ecological network analysis with biomonitoring. Our results also highlight the urgent need for long-term data to inform conservation strategies.Although biological invasions are a well-known driver of biodiversity loss in freshwaters, their impact on the structure of aquatic food webs remains relatively poorly investigated. This study examined changes in aquatic community networks driven by biological invasions in the lower Po River Basin, Italy, over the past 3 decades. Using network analysis of fish and macroinvertebrate communities at early (before 1991) and late (after 2009) stages of the invasion, we reveal a significant simplification of the structure of the food web, characterized by reduced species richness and fewer connections, as well as a shift from balanced community control to predominantly bottom-up forces in the late invasion stage. Environmental data showed a shift towards turbid, hypoxic conditions consistent with bioturbation and vegetation loss caused by invasive carp. Native predators such as Esox cisalpinus were replaced by tolerant non-native invertivorous fish species and predators such as Silurus glanis, indicating trophic reorganization. Canal size influenced invasion outcomes; large canals experienced the greatest species loss, likely due to size-refuge effects reducing top-down control. Asymmetrical trophic interactions and redundancy analyses further support the dominance of bottom-up effects in late-stage communities. These findings align with the invasional meltdown hypothesis, whereby one invader facilitates others, thereby amplifying ecosystem disruption. Despite limitations in the available data, including the absence of pre-invasion baselines and estimates of basal biomass, our results emphasize the advantage of using ecological network analysis with biomonitoring. Our results also highlight the urgent need for long-term data to inform conservation strategies
Validation of a lipopeptide approach to a safe-and-sustainable-by-design strategy on TiO2 nanoparticles UV filters
No full textTitanium dioxide nanoparticles (TiO2 NPs) are well suited for cosmetics and polymer films because they efficiently absorb UV light while remaining transparent to visible light. Their widespread use requires strategies for managing potential human and environmental risks. Implementing the Safe and Sustainable by Design (SSbD) methodology to advanced chemicals and materials is a major global challenge and a concept that is included in several EU research projects. This study employed a SSbD strategy by functionalizing the surface of TiO2 nanoparticles with a lipopeptide-based biosurfactant (Sodium Surfactin, SS). A colloidal heterocoagulation approach was used to produce SS-modified TiO2 nanoparticles. Different design options (TiO2 source, order of addition, TiO2/SS weight ratio) were investigated, and the properties were compared by measuring the UV filtering capability, photoreactivity, dustiness index, biological and ecotoxicological endpoints. This allowed us to estimate the safety and sustainability profile in agreement with the steps suggested by the JRC SSbD framework. The lipopeptide-based coating was essential for managing UV light-induced photoactivity and significantly lowering both in vitro cytotoxicity and ecotoxicity while simultaneously enhancing photostability when applied in cosmetic formulations. These results demonstrate that a colloidal process, which can be easily scaled up for industrial purposes, is a promising and exploitable SSbD strategy for the design and implementation of TiO2 NPs based UV filters
Vav1 Sustains the Expression of Insulin, PDX1 and miR-375 During Differentiation of hiPSCs to β Cells: A Potential Target to Improve the In Vitro Generation of Insulin-Producing Cells
No full textBackround: Human-induced pluripotent stem cells (hiPSCs) have emerged as a promising source of transplantable insulinproducing cells (IPCs) to restore insulin levels in Type 1 Diabetes (T1D) patients. Despite progress, obtaining fully functional β cells from hiPSCs remains challenging, underscoring the need to better understand the intracellular mechanisms involved. We investigated here the potential role of Vav1, a multidomain protein that we identified as crucial for the maturation of human biliary stem cells (hBTSCs) into β-like cells and in the trans-differentiation of pancreatic adenocarcinoma (PDAC) cells into IPCs; METHODS: Levels and subcellular localization of Vav1 were investigated throughout a seven-step differentiation process of hiPSCs to β cells. Vav1expression was forcedly modulated in pancreatic progenitors, and the potential effects were evaluated on insulin production and on PDX1, miR-375, and Akt, key regulators of β cells generation; RESULTS. Vav1 showed dynamic modulation, with pancreatic precursor cells requiring adequate levels of the protein to generate IPCs. Results: Vav1 sustains the expression of PDX1, a primary regulator of insulin expression, and of its target miR-375, essential for determining β cell mass. Furthermore, Vav1 reduction correlated with increased activation of Akt, which regulates cell survival and insulin secretion in β cells and is down-regulated by miR- 375. Conclusion: Our findings suggest the existence of a Vav1/PDX1/miR-375/Akt axis as part of the complex network orchestrating the generation of functional β cells. These insights indicate that strategies aimed at specifically modulating Vav1 levels may positively impact the generation of IPCs in vitro and, ultimately, β cell replacement therapy for T1D
Molecular mechanisms of mitochondrial function in neurodegenerative diseases
No full textMitochondria regulate cellular homeostasis and function in both neurons and glial cells, but molecular mechanisms are not fully understood. Recent advances have expanded our understanding of how mitochondrial dynamics, quality control, bioenergetics, redox regulation, and proteostasis contribute to neurodegenerative processes. The collection “Neuroscience: Mitochondrial Function in Neurons and Glia” highlights the pivotal role of mitochondria in energy production, redox signaling, calcium buffering, and apoptosis. Articles within this collection discuss the effects of mitochondria in neurodegeneration. Together, these studies emphasize ongoing challenges in defining cell type specific mitochondrial responses and point to the need for improved strategies to target mitochondrial dysfunction in neurological disease
When Better Quenching Means Lower Yields: Electrostatic Control of Cage Escape
No full textPhotoredox catalysis often relies on excited-state quenching data to rationalize performance, yet such metrics can
obscure the impact of solvent cage escape on overall efficiency. We report a systematic study of the effect of electrostatic interactions on the excited-state quenching, cage escape, and back-electron transfer processes in a benchmark system comprising methyl viologen (MV2+) and differently carboxylated ruthenium polypyridyl complexes with net charges from 2+ to 4−. Increasing electrostatic attraction between photosensitizer and MV2+ enhances the quenching rate constant (kq) up to the diffusion limit but simultaneously suppresses cage escape
quantum yields, resulting in an inverse correlation between kq and photochemical MV•+ production. Transient absorption spectroscopy confirms that cage escape, rather than quenching or back-electron transfer, governs the quantum yield of product formation. Protonation of carboxylate groups to yield uniformly 2+ complexes
equalizes quenching rates and substantially increases cage escape efficiency for the originally anionic species. These results establish electrostatic control of charge separation as a decisive factor in photoredox catalysis and challenge the practice of predicting yields solely from quenching experiments. Consideration of both the initial and post-electron-transfer charges of the photocatalyst/quencher pair emerges as a general design principle for maximizing cage escape and, consequently, photoredox reaction efficiency.Photoredox catalysis often relies on excited-state quenching data to rationalize performance, yet such metrics can obscure the impact of solvent cage escape on overall efficiency. We report a systematic study of the effect of electrostatic interactions on the excited-state quenching, cage escape, and back-electron transfer processes in a benchmark system comprising methyl viologen (MV2+) and differently carboxylated ruthenium polypyridyl complexes with net charges from 2+ to 4-. Increasing electrostatic attraction between photosensitizer and MV2+ enhances the quenching rate constant (k q ) up to the diffusion limit but simultaneously suppresses cage escape quantum yields, resulting in an inverse correlation between k q and photochemical MV center dot+ production. Transient absorption spectroscopy confirms that cage escape, rather than quenching or back-electron transfer, governs the quantum yield of product formation. Protonation of carboxylate groups to yield uniformly 2+ complexes equalizes quenching rates and substantially increases cage escape efficiency for the originally anionic species. These results establish electrostatic control of charge separation as a decisive factor in photoredox catalysis and challenge the practice of predicting yields solely from quenching experiments. Consideration of both the initial and post-electron-transfer charges of the photocatalyst/quencher pair emerges as a general design principle for maximizing cage escape and, consequently, photoredox reaction efficiency
FORMAZIONE E DECOLONIZZAZIONE: IL VILLAGGIO DI SAN BASILIO DE PALENQUE IN COLOMBIA
No full textIl contributo presenta il primo resoconto di una ricerca di campo che si è svolta dal 9 al 23 gennaio ed è tutt’ora in corso presso la comunità di San Basilio de Palenque in Colombia. L’indagine si è avvalsa di interviste semi-strutturate, osservazioni sistematiche sul campo, raccolta di narrazioni libere, nonché di una ricognizione bibliografica sul tema. L’obiettivo dello studio è nell’indagare il senso della formazione presso le comunità afrodiscendenti dei Palenqueors, ex schiavi deportati dall’Africa in America Latina, e venduti al mercato degli schiavi di Cartagena de Indias. Attraverso una prospettiva pedagogica decoloniale (Burgio, 2022) si è cercato di mettere in evidenza il valore educativo della differenza nel campo inter e trans-culturale (Lopez, 2018) e dei processi di costruzione della conoscenza presso la comunità afrodiscendente di San Basilio. Si tratta di un’opera di scavo archeologico (Mariani, 2003) volta a studiare il senso educativo di sistemi di razionalità molto lontani dalle nostre tradizioni. Il lavoro ha un impianto epistemologico di tipo ermeneutico, e postula una pedagogia interpretativa (Malavasi, 1992). Pertanto, il riferimento è a una metodologia di stampo qualitativo con approccio etnografico (Bove, 2019), intesa come un’epistemologia normativa
Fragment-based discovery of novel small molecule targeting human BAG3
No full textBcl-2-associated athanogene 3 (BAG3) is a multifunctional co-chaperone protein that regulates apoptosis,
autophagy, and proteostasis through interactions with HSP70 and other partners. Overexpression of BAG3
contributes to tumor cell survival, metastasis, and chemotherapy resistance, making it an appealing but challenging
anticancer target due to its intrinsic disorder and lack of structural data. Here, we report a fragmentbased
drug discovery (FBDD) approach to identify novel small molecules targeting human BAG3. A fragment
library of 783 compounds was screened using a thermal shift assay (TSA) against recombinant BAG3 expressed in
mammalian cells, followed by hit validation through ligand-observed NMR (WaterLOGSY). Eleven fragments
stabilized the protein, and seven were confirmed as binders. Among them, a 6-chloro-2-oxindole fragment (Fr1)
exhibited the strongest interaction, with a dissociation constant (KD) of 97.8 ± 11.1 μM. Structure–activity
relationship (SAR) studies focused on maintaining the 6-chloro-2-oxindole core and optimizing substitutions at
position 3, identified derivative 7 as a promising lead. Derivative 7 bound BAG3 with improved affinity (KD ≈ 22
μM), as confirmed by grating-coupled interferometry, and displaced Fr1 in competition NMR assays. This work
demonstrates the feasibility of applying FBDD to intrinsically disordered and structurally unresolved proteins
such as BAG3, providing a validated chemical starting point for the development of selective BAG3 inhibitors.
These findings expand the druggability landscape of BAG3 and highlight fragment-based methodologies as
powerful tools to explore protein–protein interaction targets previously considered intractable
Deep Learning for Fault Diagnosis
No full textThis paper aims to examine renewable energy conversion systems with an eye towards using deep learning for fault diagnosis and detection. Nevertheless, hyperparameter selection is crucial to the performance of deep learning models. The work exploits a genetic algorithm to tweak these hyperparameters in this study to improve the overall efficiency and performance of the considered renewable energy conversion system. By conducting extensive simulations and analysis, the study determines how to optimise the hyperparameters to minimise the effects of the system’s performance, tackling possible faults and making the most of deep learning within the framework of a renewable energy conversion system. The diagnostic achievements show that the calculation time is improved and the efficiency is achieved when compared to classical solutions available in the related literature
Margiotta e l’ermeneutica formativa Indagine sui Kleine Schriften di Gadamer
No full textGià nella Presentazione Margiotta rende nitida la posizione che vuole assumere, dal momento che chiarisce, in quanto curatore, una scelta degli scritti di Gadamer comparsi nel primo volume dei Keline Schriften (1967) tale da rispettare la successione cronologica ma puntando lo sguardo, con l’approvazione dell’autore, su quelli che «rivelano come l’orizzonte educativo sia intrinseco alla stessa ermeneutica, e come questa possa, a giusto diritto, offrirsi come possibile tematizzazione di un principio di una metodica universale del processo educativo» (Margiotta, in Gadamer: 1973, p. 5). Due elementi assumono un ruolo rilevante, che troverà approfondimenti nella Nota conclusiva: il fattore intrinseco all’ermeneutica della questione educativa e la possibilità di individuarvi una relativa metodica universale. Del resto, il sottotitolo della Nota stessa si può ritenere programmatico: Dalla progettualità educativa alla pedagogia come scienza.
Questo articolo intende riflettere su di uno dei primi lavori di un pedagogista, Umberto Margiotta, che fu protagonista del dibattito accademico internazionale
Iridium Complexes Based on 1H-imidazo[4,5-f][1,10]Phenanthroline Ligand: Photophysical Properties and Light-Emitting Electrochemical Cells Characterization
No full textCyclometallated Ir(III) complexes are extensively used in luminescent devices such as Light-Emitting Electrochemical Cells
(LECs) due to their high stability and also high luminescence quantum yields. To increase the promising complexes for LEC
applications, efforts are focused on the design of molecules with specific ligands that can modulate the emission color as well as
the nature of the excited state from which radiative decays occur. In this context, this work presents a study of the luminescent
properties of two new Ir(III) complexes containing a ligand derived from 1H-imidazo[4, 5-f][1,10]phenanthroline (dmbip). This
study, complemented by theoretical DFT calculations and electrochemical characterizations, shows that, in solution, both Ir(III)
complexes exhibit the same emission energy as that of the free dmbip ligand. However, in the solid state, the complexes exhibit
phosphorescent emission with amarked red shift of nearly 100 nm relative to their performance in solution. This unusual behavior
is due to the presence of a luminescent 3ILCT excited state in the solid state,whose population is favored by the heavymetal center.
Furthermore, these complexes were characterized in LEC devices and displayed the same emission profile identified in solid-state
photoluminescence.Cyclometallated Ir(III) complexes are extensively used in luminescent devices such as Light-Emitting Electrochemical Cells (LECs) due to their high stability and also high luminescence quantum yields. To increase the promising complexes for LEC applications, efforts are focused on the design of molecules with specific ligands that can modulate the emission color as well as the nature of the excited state from which radiative decays occur. In this context, this work presents a study of the luminescent properties of two new Ir(III) complexes containing a ligand derived from 1H-imidazo[4, 5-f][1,10]phenanthroline (dmbip). This study, complemented by theoretical DFT calculations and electrochemical characterizations, shows that, in solution, both Ir(III) complexes exhibit the same emission energy as that of the free dmbip ligand. However, in the solid state, the complexes exhibit phosphorescent emission with a marked red shift of nearly 100 nm relative to their performance in solution. This unusual behavior is due to the presence of a luminescent 3ILCT excited state in the solid state, whose population is favored by the heavy metal center. Furthermore, these complexes were characterized in LEC devices and displayed the same emission profile identified in solid-state photoluminescence