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Networks of Hebbian networks: more is different
No full textThe common thread behind the recent Nobel Prize in Physics to John Hopfield and those conferred to Giorgio Parisi in 2021 and Philip Anderson in 1977 is disorder. Quoting Philip Anderson: more is different. This principle has been extensively demonstrated in magnetic systems and spin glasses, and, in this work, we test its validity on Hopfield neural networks to show how an assembly of these models displays emergent capabilities that are not present at a single network level. Such an assembly is designed as a layered associative Hebbian network that, beyond accomplishing standard pattern recognition, spontaneously performs also pattern disentanglement. Namely, when inputted with a composite signal – e.g., a musical chord – it can return the single constituting elements – e.g., the notes making up the chord. Here, restricting to notes coded as Rademacher vectors and chords that are their mixtures (i.e., spurious states), we use tools borrowed from statistical mechanics of disordered systems to investigate this task, obtaining the conditions over the model control-parameters such that pattern disentanglement is successfully executed
Evaluation of multi-lure sex pheromone traps for simultaneous monitoring of five grapevine moth pests
No full textGrape is currently cultivated on over 7 million hectares worldwide and is frequently exposed to arthropod pest invasions. Developing efficient and cost-effective monitoring methods is crucial for the bio-surveillance of key grapevine moth pests, including invasive species, and for implementing integrated pest management programs. In this study, five vine-damaging moth species, i.e., Lobesia botrana, Eupoecilia ambiguella, Argyrotaenia ljungiana, Cryptoblabes gnidiella and Paralobesia viteana (Lb, Ea, Al, Cg, and Pv), were simultaneously monitored using traps baited with single synthetic sex pheromones, paired combinations of pheromones, and a combination of all five pheromones. The field trials were conducted in three different wine-growing regions (i.e. Northern, Central, and Southern Italy) over two years. Results suggest that some combinations of sex pheromones are more effective than others in catching the target species. Of note, multispecies traps could be used for simultaneous monitoring of C. gnidiella, L. botrana and A. ljungiana, with only a modest reduction in captures for some of these target moth species and these could be incorporated into multiple species surveillance programs. Overall, this research provides useful data to design and optimize the efficacy of multilure traps for advanced monitoring of key vine-damaging moths
Chemical composition and biological activities of nine essential oils obtained from Algerian plants
No full textThe essential oils (EOs) from nine species (Artemisia campestris, A. herba-alba, Juniperus foetidissima, Laurus nobilis, Mentha pulegium, M. spicata, Rosmarinus officinalis, Salvia officinalis, and Thymus vulgaris) of the Algerian flora have been hydrodistilled, analysed, and tested for their antioxidant and antiproliferative properties. A. campestris EO showed a higher content of terpene hydrocarbons; A. herba-alba EO was mainly rich in their oxygenated derivatives. Sesquiterpenes were the most abundant compounds in J. foetidissima EO, while oxygenated monoterpenes and phenylpropanoids prevailed in L. nobilis EO. The other EOs were rich in oxygenated monoterpenes, with quality–quantitative differences. T. vulgaris and L. nobilis performed better in all the antioxidant assays, respectively with IC50 values ranging from 0.0002 and 0.0012 mg/mL in the CUPRAC assay to 2.83 and 3.50 mg/mL in the FRAP assay. T. vulgaris was also the only EO exhibiting an antiproliferative activity towards the human breast (MCF-7) and lung (A549) cancer cell lines
The “Authentic Islam” on the Internet: The Official Websites of the Ministries of Religious Affairs in Algeria, Morocco, and Tunisia
No full textThe governments of the Maghreb states appropriated and subordinated Islam after gaining independence, utilizing religion to strengthen national identity, unity, and establish political power. The goal of governmental control over religious doctrine was to stop “heterodox” Muslim beliefs and behaviors from deviating from the officially sanctioned conceptual framework of a national Islam. This study will employ a comparative methodology to examine the little-known function of the websites of the Ministries of Religious Affairs in Algeria, Morocco, and Tunisia. It will highlight differences in the aims and scopes of these websites, as well as the state’s use of the Internet for religious purposes
Antimicrobial resistance and virulence-associated genes in Escherichia coli from young healthy chickens
No full textEscherichia coli is a commensal intestinal bacterium of humans and animals and is frequently associated with antimicrobial resistance (AMR). This study investigated the phenotypic and genotypic AMR and virulence factors in E. coli isolated from 120 young healthy chickens never treated with antibiotics and coccidiostats. The disk diffusion method employed on all 120 isolates revealed the highest resistance (11.67%) to chloramphenicol and trimethoprim-sulfamethoxazole. All isolates were susceptible to aztreonam and gentamicin, whereas over 95% showed susceptibility to amikacin, cefoxitin, ciprofloxacin, and ertapenem. Minimum inhibition concentration test found 7 (5.83%) isolates resistant to colistin. Eight strains (6.67%) were found to be multidrug-resistant (MDR). Molecular analyses conducted on resistant and intermediate isolates showed that 11/13 penicillin-resistant strains carried the blaTEM gene, 12/12 tetracycline-resistant strains had tetA, 4/14 chloramphenicol-resistant and 1/2 chloramphenicol-intermediate strains had cmlA. The astA gene, potentially indicative of enteroaggregative E. coli (EAEC), was found in 15% of isolates. Virulence genes characterizing other pathotypes investigated were not detected. Chickens reared in optimal conditions and never treated with antibiotics may harbor antimicrobial-resistant and pathogenic bacterial strains that could become a public health hazard. Good farm management and hygiene are fundamental to reducing the circulation of pathogenic strains and the need for antimicrobial treatments
When Few Mosquitoes Are Enough: Dengue outbreaks in non-endemic areas
No full textDengue is no longer limited to tropical regions, as recent outbreaks in Southern Europe show. In 2024, nearly 150 local cases were reported in Fano, Italy, raising concerns that dengue could become established in temperate areas. In this work, we question the common belief that large outbreaks require high numbers of mosquitoes and a high basic reproduction number (R0). We show that significant outbreaks can happen even when R0 is below one, triggered by the random introduction of infected travelers. Using a mathematical model that includes imported cases and mosquito populations, we explain how rare but possible transmission events can cause substantial local spread, even under conditions usually thought too weak for sustained outbreaks. Our findings point out an important gap in current risk assessments, which often rely only on fixed invasion thresholds and basic reproduction numbers. By considering the complex interactions between human travel, mosquito ecology, and the environment, our work supports the One Health approach to understanding disease emergence. We recommend combining stochastic modeling, data on human movement, and mosquito surveillance in early warning systems to better predict outbreaks’ risk and improve preparedness in regions not traditionally affected by dengue
Adaptive hyper-reduction of non-sparse operators: Application to parametric particle-based kinetic plasma models
No full textThis paper proposes an adaptive hyper-reduction method to reduce the computational cost associated with the simulation of parametric particle-based kinetic plasma models, specifically focusing on the Vlasov-Poisson equation. Conventional model order reduction and hyper-reduction techniques are often ineffective for such models due to the non-sparse nature of the nonlinear operators arising from the interactions between particles. To tackle this issue, we propose an adaptive, structure-preserving hyper-reduction method that leverages a decomposition of the discrete reduced Hamiltonian into a linear combination of terms, each depending on a few components of the state. The proposed approximation strategy allows to: (i) preserve the Hamiltonian structure of the problem; (ii) evaluate nonlinear non-sparse operators in a computationally efficient way; (iii) overcome the Kolmogorov barrier of transport-dominated problems via evolution of the approximation space and adaptivity of the rank of the solution. The proposed method is validated on numerical benchmark simulations, demonstrating stable and accurate performance with substantial runtime reductions compared to the full order model
