Self-avoiding closed curves in the regular and semiregular grids

We consider closed curves in the three regular and eight semiregular grids in the plane, in which each vertex and each edge can be repeated a limited number of times. We define the conditions for such curves to be self-avoiding, and we present a linear-time algorithm to check them. We define the orientation of such curves. We propose a classification of their vertices, and we give a unifying formula relating the number of different types of vertices, valid in the regular and semiregular grids. Our results can be used in the plane tiling applications

Rethinking Holistic Ai Development Through Social Diversity, Interdisciplinary Collaboration and Integrative Knowledge Production

The rapid deployment of AI reveals persistent socio-technical and data-driven biases that reflect profound epistemic limitations in knowledge production. These biases are not accidental, but symptomatic of deeper epistemic limitations in the way AI knowledge is produced — often by homogeneous teams within technocentric paradigms that exclude alternative perspectives. This paper argues that the underrepresentation of diverse social actors in AI development not only perpetuates inequality, but also severely limits the epistemic and ethical robustness of AI systems. The focus of this paper arises in particular from the preliminary findings obtained in the Horizon Europe project STEP, which highlight the potential of the framework to improve the inclusivity and trustworthiness of AI. The central thesis is that social diversity must be considered as an epistemic condition and not just an ethical or demographic ideal. Drawing on sociology, psychology and educational science, the authors show how integrating plural forms of knowledge, lived experiences and cultural perspectives into the design and development process can lead to AI systems that are more context-sensitive, equitable and trustworthy. Rather than proposing inclusion as an external corrective, this paper discusses a paradigm shift in AI development - a paradigm shift that embeds diversity into the infrastructure of knowledge production itself. The contribution of this paper is twofold. First, it proposes a theoretical model of integrative knowledge production that identifies mechanisms through which interdisciplinary collaboration can challenge dominant epistemologies and promote systemic reflexivity. Second, a participatory design framework is outlined to operationalise this model through concrete methodological tools, including dialogic co-design workshops, ethnographic participation in data selection and cross-functional team structuring. These practises aim to break through technocratic compartmentalisation by creating space for social critique and situated intelligence within AI development cycles. Finally, the authors reflect on the transformative potential of this approach and suggest that rethinking who is involved in AI knowledge production will not only change the outcomes of AI systems, but also the normative foundations of the technological future. From this perspective, ethical AI is not just explainable or compliant — it is structurally inclusive, responsive to different lifeworlds and open to critical reinvention

mGlu5 receptor negative allosteric modulation reduces the aberrant cellular reactivity and neurotoxicity of iNPCs-derived human astrocytes differentiated from ALS patients

BACKGROUND. Amyotrophic Lateral Sclerosis (ALS) is a multifactorial and non-cell-autonomous neurodegenerative disease, characterized by brainstem and spinal cord motor neuron (MN) death. The etiopathological mechanisms are numerous and among them, glutamate excitotoxicity plays a major role. The metabotropic glutamate receptor type 5 (mGluR5) fine modulates glutamate neurotransmission other than astrocyte reactivity, and this mechanism can be exploited as potential target to counteract MN loss in ALS. We provided in-vitro and in-vivo evidence showing that genetic ablation or the pharmacological modulation of mGluR5, by the selective negative allosteric modulator CTEP, positively affects the reactive phenotype and neurotoxicity of ALS astrocytes and significantly improved the life span and disease progression in SOD1G93A ALS mice. Here we investigated in-vitro the impact of mGluR5 modulation by CTEP on human i-Astrocytes differentiated from inducible neural progenitor cells (iNPCs) obtained from skin fibroblasts of ALS patients and healthy donors. With this aim, we monitored the cellular phenotype of i-Astrocytes when exposed to 100nM CTEP by exploiting molecular biology and immunohistochemical studies. We monitored the intracellular calcium level by live imaging and fluorometric detection, moreover we quantified the secretion of neurotoxic factors by ELISA assay. The accumulation of reactive oxygen species, as well as oxidative stress markers have been investigated by immunohistochemical and biochemical studies, moreover we measured the activity of antioxidant response enzymes. As an indirect, but very important readout, we finally investigated the neurotoxicity of the astrocyte conditioned medium on human-derived motor neurons differentiated from iPSCs of healthy donors and ALS patients. RESULTS. In-vitro pharmacological modulation with CTEP did not alter the mGluR5 total expression in i-Astrocytes. RT-qPCR analyses, western blot and immunohistochemical experiments showed that 5 days in-vitro exposure to 100nM CTEP reduced the over-expression of astrogliosis (GFAP, S100β, C3) and neuroinflammation (NLRP3) markers (p<0.05; two-way ANOVA) in i-Astrocytes from ALS-patients vs. untreated or control cells. CTEP treatment was also able to restore oxidative stress conditions by promoting Nrf2 nuclear translocation, enhancement of the antioxidant enzymes activity (glutathione reductase, glutathione peroxidase, glucose-6-phosphate dehydrogenase, catalase), and consequent reduction of ROS and direct oxidative stress markers (p<0.001; two-way ANOVA) in ALS i-Astrocytes. Acute CTEP in-vitro treatment significantly reduces the intracellular calcium mobilization upon mGlu5 receptor activation, in ALS and control i-Astrocytes. On the other hand, the reduced astrocyte reactivity by CTEP treatment translates into a beneficial effect towards iPSCs-derived MNs exposed to the conditioned medium collected from i-Astrocytes. CONCLUSIONS. We here show that the in-vitro pharmacological allosteric blockade of the mGluR5 by CTEP positively affects the reactive phenotype of human-derived i-Astrocytes differentiated form from C9orf72 and SOD1A4V ALS patients, mainly by ameliorating the general oxidative stress response and reducing the release of toxic factors. These data extend our previous results in SOD1G93A in-vitro and in-vivo models, thus further encouraging a translational application of mGluR5 modulators in clinical trials

The search for point-like neutrino sources with ANTARES and KM3NeT-ARCA telescopes

The multi-messenger approach has recently paved the way for possible breakthroughs in our comprehension of high energy particle emission in the Universe. Neutrino telescopes are essential for highlighting the hadronic component of these phenomena, in addition to testing possible correlation with known sources of gamma rays. Joint analyses of data from complementary facilities may provide enhanced sensitivity. This contribution explores the sensitivity as a function of the source declination for a combined analysis of data collected by two neutrino telescopes located in the depths of the Mediterranean Sea, ANTARES and KM3NeT/ARCA. A catalogue of approximately one hundred point-like and extended sources is presently investigated for neutrino emissions: the list encompasses bright γ-ray emitters, galactic γ-ray sources, extragalactic sources as radio-loud AGNs and the most significant candidate sources studied by IceCube

Analisi di suscettibilità al dissesto franoso per la sicurezza e la funzionalità di infrastrutture di trasporto di superficie

In caso di eventi franosi che coinvolgono infrastrutture di trasporto di superficie, oltre al danno sugli elementi colpiti direttamente, si verificano impatti negativi derivanti dall’interruzione di servizi fondamentali. D’altra parte, le stesse infrastrutture sono un’importante concausa dello sviluppo di alcuni tipi di frane. In questo contesto la comprensione delle relazioni tra fenomeni di dissesto e infrastrutture di superficie diventa importante per un’efficiente gestione del rischio frana. Nell’ambito del Partenariato Esteso PNRR “RETURN” si sta sperimentando una metodologia statistica per la redazione di mappe di suscettibilità, come strumento per identificare sia le porzioni di territorio maggiormente predisposte al dissesto, sia le caratteristiche più influenti per lo sviluppo di tali fenomeni. Si sta considerando inoltre l’applicazione di tale metodologia, una volta consolidata, anche in ambiti di maggior dettaglio e soggetti a condizioni particolari, tra cui le aree di interazione terreno - struttura dei ponti

Elderly specific DRT in Italy and Japan: the factors influencing the DRT usage in Genoa and Toyoake City

The ageing of the world's population is a growing phenomenon. Numerous studies have shown that mobility is a key factor for active and healthy ageing. In this context, demand-responsive transport (DRT) plays a key role, as it offers better accessibility and inclusiveness to the over-65s compared to traditional public transport, which is often under-used by the elderly. The aim of this article is to compare two DRT services for older people operating in distinct geographical and cultural contexts , such as Genoa (Italy) and Toyoake City (Japan). Two questionnaires were administered to the users in order to identify the factors influencing the increase in DRT usage. It is then possible to suggest to decision makers what improvements should be made to increase DRT in both areas. The results show that availability of DRT and accessibility to DRT stops are key factors in both contexts