Scuola Normale Superiore

Soft failures in optical networks pose a significant challenge, as their detection and localization are notoriously difficult. This often leads to suboptimal mitigation strategies being implemented before the root cause is identified. To address this, the longitudinal power monitoring (LPM) technique has gained significant attention in recent years. LPM leverages information from the coherent receiver to compute the power evolution along the optical path. This paper presents an architecture that integrates the power profile information retrieved from the receiver with the SDN controller. The result is a self-healing optical network capable of locating soft failures in its lightpaths and providing finely tuned reconfigurations to solve them. By developing an OpenConfig-compliant YANG model, we implemented a gNMI streaming mechanism to transmit power profile metrics every 1.5 s from the receiver to the SDN controller. This process utilizes two SDN applications that combine the received data at the controller to finalize the power profile computation and pinpoint the location of soft failures. The architecture’s effectiveness is demonstrated through two scenarios. In the first scenario, the SDN controller accurately identifies and resolves attenuation caused by VOAs strategically placed along a span. In the second scenario, the controller jointly examines the power profiles of two lightpaths to locate a faulty WSS that is causing attenuation in only one of them.

This paper presents a novel proof-theoretic approach to a logic specifically designed to handle exceptions and typicality. Our method extends the classical first-order sequent calculus by incorporating a specialized framework to manage both negative extra-logical information (explicit exceptions) and positive information (background assumptions). We prove that the resulting sequent calculi satisfy the cut-elimination theorem, thereby ensuring strong analytical properties. Furthermore, we show how this framework effectively models traditional reasoning patterns involving conflicting information and typicality. Finally, we establish a natural correspondence between our approach and the Kraus-Lehmann-Magidor postulates, further grounding our work within established theoretical foundations.

Gaussian states of bosonic quantum systems enjoy numerous technological applications and are ubiquitous in nature. Their significance lies in their simplicity, which in turn rests on the fact that they are uniquely determined by two experimentally accessible quantities, their first and second moments. But what if these moments are only known approximately, as is inevitable in any realistic experiment? What is the resulting error on the Gaussian state itself, as measured by the most operationally meaningful metric for distinguishing quantum states, namely, the trace distance? In this work, we fully resolve this question by demonstrating that if the first and second moments are known up to an error ε , the trace distance error on the state also scales as ε , and this functional dependence is optimal. To prove this, we establish tight bounds on the trace distance between two Gaussian states in terms of the norm distance of their first and second moments. As an application, we improve existing bounds on the sample complexity of tomography of Gaussian states.

In this article, I analyze the impact of populist ‘politics of immediacy’ on parliaments’ roles, focusing on the prohibition of the imperative mandate codified in many Western constitutions, especially in Europe. ‘Politics of immediacy’ refers to a form of politics that rejects the mediation offered by representative institutions. While constitutional scholars often focus on populist misuse of referenda as an aspect of immediacy, I explore another dimension – how populist advocacy for the return of the imperative mandate challenges parliamentary legitimacy. The article examines how populists view parliaments, using a case study on Italy to illustrate how this phenomenon undermines parliaments’ representative role. Italy's post-World War II (WWII) constitution, shaped by the memory of totalitarian horrors, provides a valuable lens to study the attack on parliamentary democracy. This phenomenon reflects a broader European trend but is particularly acute in Italy, where populist demands for the imperative mandate threaten to erode democratic safeguards established after WWII. By highlighting the Italian case from a comparative perspective, the article underscores the risks posed by immediacy politics to democratic institutions and offers insights into preserving parliamentary autonomy in the face of such challenges.

Upper-limb occupational exoskeletons reduce injuries during overhead work. Previous studies focused on muscle activation with and without exoskeletons, but their impact on shoulder fatigue remains unclear. Additionally, no studies have explored how exoskeleton support levels affect fatigue. This study investigates the effects of assistive profiles on muscular and cardiovascular fatigue. Electromyographic (EMG) and electrocardiographic signals were collected to compute EMG median frequency (MDF), heart rate (HR), and heart rate variability (HRV). Fatigue was assessed using three MDF and HR metrics: relative change ( ${\mathrm{MDF}}_{\Delta }$ , ${\mathrm{HR}}_{\Delta }$ ), slope ( ${\mathrm{MDF}}_{\mathrm{slope}}$ , $\mathrm{H}{\mathrm{R}}_{\mathrm{slope}}$ ), and intercept ( ${\mathrm{MDF}}_{\mathrm{intercept}}$ , $\mathrm{H}{\mathrm{R}}_{\mathrm{intercept}}$ ) of the linear regression. Results showed ${\mathrm{MDF}}_{\Delta }$ decreased 64% (p = 0.0020) with higher assistance compared to no exoskeleton; ${\mathrm{HR}}_{\Delta }$ decreased 40% (p < 0.0273) with lower assistance, ${\mathrm{MDF}}_{\mathrm{slope}}$ decreased up to 67% (p = 0.0039) and $\mathrm{H}{\mathrm{R}}_{\mathrm{slope}}$ by 43% (p < 0.0098) with higher and medium assistance. HRV metrics included root mean square of successive differences (RMSSD) and low-frequency to high-frequency power ratio (LF/HF). RMSSD indicated parasympathetic dominance, while rising LF/HF ratio suggested physiological strain. Findings support occupational exoskeletons as ergonomic tools for reducing fatigue.

We consider the differential of a self-consistent transfer operator at a fixed point and show that its spectral properties can be used to establish a form of local exponential convergence to equilibrium: probability measures near the fixed point converge exponentially fast to the fixed point by the iteration of the transfer operator. This result holds even in the strong coupling case. Additionally, we show that for mean field coupled systems satisfying a uniform Lasota–Yorke inequality the differential also satisfies this condition. Finally, we provide examples applying these general results to self-consistent transfer operators based on deterministic expanding maps with various couplings, extending beyond the weak coupling regime.

In this paper, I investigate how the affective component of smell can be implicitly biased and, more broadly, I provide reasons for the importance of taking into account the affective component of perceptual implicit bias. After introducing the notion of perceptual implicit bias, I delineate the case of affective perception for the sense of smell: since olfactory experience typically has a strong affective load, affective properties should, in those cases, be considered part of the perceptual states themselves. Next, I explore why certain smells are perceived to be pleasant or unpleasant, defending the hypothesis that the cultural setting of the perceiver plays an important role in determining the perceived pleasantness of smells. Then, I argue that some instances of affective olfactory perception should be conceived as cases of implicit bias, conditioned by the cultural context of the perceiver. Lastly, I sketch general considerations on the importance of including the affective component in the study of implicitly biased perception.

Mechanical force plays a pivotal role in all aspects of axon development. In this paper, the use of nano‐pulling, a technology that enables the intracellular generation of extremely low mechanical forces is explored. It is demonstrated that force‐mediated axon growth also exerts global effects that extend to the nuclear level. The mechanistic studies support a model in which exogenous forces induce microtubule stabilization, and significant remodeling of perinuclear microtubules, which preferentially align perpendicularly to the nuclear envelope. An increase in the lateral tension of the nucleus is observed, leading to substantial remodeling of nuclear morphology, characterized by an increase in nuclear grooves and a higher sphericity index (indicating less flattened nuclei). Notably, these changes in nuclear shape are linked to chromatin remodeling, resulting in global transcriptional activation.

The paper introduces a relevant containment logic according to which the analytic implication $\varphi \twoheadrightarrow \psi$ is analyzed as the conjunction of two theses: $\varphi$ contextually entails $\psi$ and $\varphi$ contextually contains $\psi$. By doing so, we are able to extend the ternary semantics of relevant logic to the analysis of topic containment, thus lifting some limitations of Richard Sylvan’s relevant containment logic. We offer a ternary account of topic containment, in that led by the consideration that topic inclusions are evaluated in situ, i.e. with respect to the discursive context fixed by an information state. The main technical result of the paper is a sound and complete axiomatisation of relevant containment logic. Finally, Sylvan’s logic turns out as a special case of our relevant containment logic.

Machine learning (ML) continues to show its potential and efficacy in automating network management tasks, such as failure management. However, as ML deployment considerations broaden, aspects that go beyond predictive performance, such as a model’s computational complexity (CC), start to gain significance, as higher CC incurs higher costs and energy consumption. Balancing high predictive performance with reduced CC is an important aspect, and therefore, it needs more investigation, especially in the context of optical networks. In this work, we focus on the problem of reducing the CC of ML models, specifically neural networks (NNs), for the use case of failure identification in optical networks. We propose an approach that exploits the relative activity of neurons in NNs to reduce their size (and hence, their CC). Our proposed approach, referred to as iterative neural removal (INR), iteratively computes neurons’ activity and removes neurons with no activity until reaching a predefined stopping condition. We also propose another approach, referred to as guided knowledge distillation (GKD), that combines INR with knowledge distillation (KD), a known technique for compression of NNs. GKD inherently determines the size of the compressed NN without requiring any manual suboptimal selection or other time-consuming optimization strategies, as in traditional KD. To quantify the effectiveness of INR and GKD, we evaluate their performance against pruning (i.e., a well-known NN compression technique) in terms of impact on predictive performance and reduction in CC and memory footprint. For the considered scenario, experimental results on testbed data show that INR and GKD are more effective than pruning in reducing CC and memory footprint.

A bstract We revisit and extend the construction of six-dimensional orientifolds built upon the T ⁴ / ℤ N orbifolds with a non-vanishing Kalb-Ramond background, both in the presence of $\mathcal{N}$ N = (1, 0) supersymmetry and Brane Supersymmetry Breaking, thus amending some statements present in the literature. In the N = 2 case, we show how the gauge groups on unoriented D9 and D5 (anti-)branes do not need to be correlated, but can be independently chosen complex or real. For N > 2 we find that the Diophantine tadpole conditions severely constrain the vacua. Indeed, only the N = 4 orbifold with a rank-two Kalb-Ramond background may admit integer solutions for the Chan-Paton multiplicities, if the ℤ 4 fixed points support O5 − planes, both with and without supersymmetry. All other cases would involve a fractional number of branes, which is clearly unacceptable. We check the consistency of the new ℤ 2 and ℤ 4 vacua by verifying the unitarity constraints for string defects coupled to Ramond-Ramond two-forms entering the Green-Schwarz-Sagnotti mechanism.

Aggregated relational data (ARD), derived from questions of the form “How many people do you know who [belong to subpopulation X]?” are widely used to estimate the size and composition of social networks, often adopting the network scale-up method (NSUM). However, their measurement properties are insufficiently studied. The authors address this gap by assessing (1) the test-retest reliability of a large set of ARD questions and NSUM-estimated network sizes and (2) the convergent validity of these network size estimates. This mixed-methods study involved a heterogeneous quota sample of 50 citizens in Barcelona, Spain, in 2023. Respondents were interviewed twice over a 10- to 15-day period, answering a series of ARD questions on each occasion. Qualitative debriefing provided valuable insights into their response behaviors. Our findings indicate that NSUM accurately ranked respondents’ network sizes but did not estimate their values consistently across measurements. Respondents gave lower answers in the second interview than in the first. In particular, the network sizes of people with large networks (“hubs”) fluctuated significantly. NSUM-estimated network size moderately correlated with estimates from the summation method and Facebook friend counts. The authors discuss the implications and provide practical recommendations for ARD item selection and the use of NSUM instruments.

This article re-examines a textual issue at Ov. Pont . 1.1.41 scimus ab imperio fieri nil tale Dianae . Specifically, it proposes the replacement of Dianae , the presence of which in this context is controversial, with Dionae , a reference to the oracular goddess at Dodona. This suggestion is supported through a comparative analysis with Strabo’s contemporary description of the oracle in Book 7 of his Geography .

Polyphenols are significant compounds that impact the winemaking process, influencing key attributes such as wine quality, color, astringency, bitterness, and chemical stability. Traditionally, the wine polyphenolic content is assessed through conventional analytical methods, which are costly and time‐consuming. Thus, developing novel strategies to overcome these limitations is highly desirable. Quartz Crystal Microbalance with Dissipation Monitoring (QCM‐D) is an electromechanical sensor that has gained broad recognition as a fast, reliable, and label‐free detection tool. The QCM‐D is employed to investigate Gelatin Type A (Gel‐A) and Mouse Proline‐Rich Protein 5 (MP5) as probes for analyzing polyphenols in red wines. The probes have been successfully immobilized on the sensor surface, yielding molecular densities of 2.1 × 10¹⁴ and 5.1 × 10¹² molecules cm⁻² for MP5 and Gel‐A, respectively. Both probes have shown promising performance in the analysis of polyphenols in wine, with both changes in the sensor's resonance frequency and dissipation with all tested samples. Notably, using MP5, a linear response of the dissipation has been observed with both the total polyphenol and hydroxybenzoic acid concentrations. These results indicate strong potential for developing a stand‐alone sensor platform to directly monitor polyphenols during the winemaking process.

This chapter analyses the processes of transnationalization of feminist movements in contemporary Europe, from the beginning of the 2010s up to the present. Transnationalization is understood here not so much as transnational activism, but rather as the diffusion of ideas, symbols and forms of action as well as the expression of transnational solidarity, both online and offline. These processes have taken place during a period in which widespread global crises are occurring at both the economic and political levels. Feminist movements in Italy, Greece and Spain are taken as paradigmatic instances, confirming the rise of a “fourth wave of feminism” that not only bears its own specific characteristics, but also displays a certain level of continuity with past feminist waves, black feminist theory and practice, while also sharing similarities with Latin American feminism. The analysis presented here demonstrates that transnationalization is the result of a mix of both contextual and agential factors: the “prolonged critical juncture” sparked supranational opportunities for resistance on the side of the weakest social subjectivities, which include women and young people. Nevertheless, contemporary feminist movements cannot be described as merely reactive, as they show a high degree of creativity and innovation that involves both their understanding of reality and repertoires of collective action.

Since the 2014–2015 so-called ‘refugee crisis’, civil society organisations have increasingly engaged in practices of political contention in the field of migration in Europe. They have done so at the sub-national, national and even transnational/supranational level, shifting their scale of contention in the context of a process of Europeanisation from below. In this contribution I explain why civil society organisations engage, in different ways and to different extents, in such processes of transnationalisation. I will do so by exploring, in the context of a comparative study, the EU-wide network From the Sea to the City, which gathers together a wide and diverse range of civil society initiatives across the continent, with a view to promoting a more open EU migration policy. Building on participant observation, semi-structured interviews and documentary sources, and using qualitative techniques, I will consider the role played by five types of internal dynamics in the decision made by civil society organisations to engage in this European transnational network. In doing so, my contribution will illustrate which internal factors matter more than others, and why this is the case, in the process of transnationalisation of migrant solidarity activism.

The Far Right is generally considered to be a significant phenomenon of the first two decades of the twenty first century, and it perhaps also represents the defining academic publishing phenomenon in political science and sociology over the same period. But what do we know about the transnationalization of the Far Right? While processes of transnationalization are well known and have long been studied in relation to left-wing, progressive actors, there is still a need for research to be carried out on how the Far Right responds to the challenges of transnationalization. This is true for both political parties and movements in an era such as the fourth wave of the Far Right, which has seen the emergence of increasingly hybrid actors on this side of the political spectrum. This chapter addresses these issues by using a number of concepts from the scholarship on social movement contention to look at the trasnationalization of different types of actors on the Right (including both political parties and non-party organizations).

This volume presents the findings of research conducted within the framework of the Transnational Political Contention in Europe project, a network that brought together a wide range of academic institutions and think tanks to investigate the attempts that have been made to transnationalize contention in the European space. Looking specifically at the period from the mid-2010s onwards, we conceive of transnational mobilization as a form of political mobilization that takes place across international borders. In this case, we refer to the European space and its neighbourhood, meaning countries involved in the European integration process. For this reason, the research focuses on the European space as an arena where civil society actors (CSOs) mobilize resorting to diverse repertoires and discursive strategies, and on the European Union (EU) as the direct or indirect target of their claims.

We study the regularity and uniqueness of weak solutions of a degenerate parabolic equation, arising as the limit of a stochastic lattice model of self-propelled particles. The angle-average of the solution appears as a coefficient in the diffusive and drift terms, making the equation nonlocal. We prove that, under unrestrictive non-degeneracy assumptions on the initial data, weak solutions are smooth for positive times. Our method rests on deriving a drift-diffusion equation for a particular function of the angle-averaged density, and applying De Giorgi’s method to show that the original equation is uniformly parabolic for positive times. We employ a Galerkin approximation to justify rigorously the passage from divergence to non-divergence form of the equation, which yields improved estimates by exploiting a cancellation. By imposing stronger constraints on the initial data, we prove the uniqueness of the weak solution, which relies on Duhamel’s principle and gradient estimates for the periodic heat kernel, as to derive $L^\infty$ estimates for the angle-averaged density.

We realize 4 of the 6 closed orientable flat 3-manifolds as a cusp section of an orientable finite-volume hyperbolic 4-manifold whose symmetry group acts transitively on the set of cusps.