Federated Unlearning: A Survey on Methods, Design Guidelines, and Evaluation Metrics

Federated Learning (FL) enables collaborative training of a Machine Learning (ML) model across multiple parties, facilitating the preservation of users' and institutions' privacy by keeping data stored locally. Instead of centralizing raw data, FL exchanges locally refined model parameters to build a global model incrementally. While FL is more compliant with emerging regulations such as the European General Data Protection Regulation (GDPR), ensuring the right to be forgotten in this context - allowing FL participants to remove their data contributions from the learned model - remains unclear. In addition, it is recognized that malicious clients may inject backdoors into the global model through updates, e.g. to generate mispredictions on specially crafted data examples. Consequently, there is the need for mechanisms that can guarantee individuals the possibility to remove their data and erase malicious contributions even after aggregation, without compromising the already acquired "good" knowledge. This highlights the necessity for novel Federated Unlearning (FU) algorithms, which can efficiently remove specific clients' contributions without full model retraining. This survey provides background concepts, empirical evidence, and practical guidelines to design/implement efficient FU schemes. Our study includes a detailed analysis of the metrics for evaluating unlearning in FL and presents an in-depth literature review categorizing state-of-the-art FU contributions under a novel taxonomy. Finally, we outline the most relevant and still open technical challenges, by identifying the most promising research directions in the field.Comment: 23 pages, 8 figures, and 6 table

Context-Aware Group Communication in Mobile Ad-Hoc Networks

Abstract. The widespread availability of both fixed and wireless network con-nectivity and the growing market of portable devices are enabling anytime and anywhere impromptu collaboration. The emergence of Mobile Ad-Hoc Net-works (MANET) further opens up new possibilities for the provisioning of ad-vanced collaborative services, such as civil protection, e-care, and troop car management. However, the design and the deployment of collaborative appli-cations in MANET scenarios raises new group management challenges. In par-ticular, MANET characteristics, e.g., unpredictable and frequent mobility of us-ers/devices, intermittent device connectivity, continuous variations of network topology, make it impossible any a-priori knowledge about group members availability and ask for novel solutions to handle properly the communication about group members. The paper proposes a context-aware communication model to govern communication on the basis of the characteristics of the com-municating parties, such as their location and their profiling information. The model provides communication patterns with different semantics to address both point-to-point and point-to-multipoint communication needs. The paper shows the implementation of the proposed model in the AGAPE framework for the design, deployment, and support of collaborative applications in MANET environments and presents the functioning of the AGAPE communication sup-port in the context of a civil protection application scenario.

P-IOTA: A Cloud-Based Geographically Distributed Threat Alert System That Leverages P4 and IOTA

The recent widespread novel network technologies for programming data planes are remarkably enhancing the customization of data packet processing. In this direction, the Programming Protocol-independent Packet Processors (P4) is envisioned as a disruptive technology, capable of configuring network devices in a highly customizable way. P4 enables network devices to adapt their behaviors to mitigate malicious attacks (e.g., denial of service). Distributed ledger technologies (DLTs), such as blockchain, allow secure reporting alerts on malicious actions detected across different areas. However, the blockchain suffers from major scalability concerns due to the consensus protocols needed to agree on a global state of the network. To overcome these limitations, new solutions have recently emerged. IOTA is a next-generation distributed ledger engineered to tackle the scalability limits while still providing the same security capabilities such as immutability, traceability, and transparency. This article proposes an architecture that integrates a P4-based data plane software-defined network (SDN) and an IOTA layer employed to notify about networking attacks. Specifically, we propose a fast, secure, and energy-efficient DLT-enabled architecture that combines the IOTA data structure, named Tangle, with the SDN layer to detect and notify about network threats

Informatica senza e con computer nella Scuola Primaria

National audienceQuesto capitolo descrive le esperienze svolte da docenti e ricercatori del Dipartimento di Informatica - Scienza e Ingegneria (DISI) dell’Alma Mater Studiorum - Università di Bologna nell’ambito di alcuni progetti di disseminazione dei principi di base dell’Informatica (pensiero computazionale) nelle scuole primarie bolognesi.L’approccio che caratterizza i progetti presentati è l’utilizzo, sequenziale o intervallato, di attività sia “unplugged” sia “plugged”. Le prime - svolte senza l’utilizzo di un calcolatore, ma con materiali e oggetti di uso comune - sono state in parte tratte dal libro CS Unplugged, e in parte ideate dagli autori; le seconde hanno fatto uso del linguaggio visuale a blocchi Scratch.Con riferimento alla Proposta di Indicazioni Nazionali per l’Informatica nella Scuola [CINI17], tali attività hanno coperto soprattutto gli ambiti prettamente informatici di rappresentazione dell’informazione (es. numeri binari), algoritmi (es. massimo) e loro descrizione in uno pseudolinguaggio, programmazione; ma non hanno tralasciato quelli di creatività digitale (realizzare un progetto personale con Scratch) e consapevolezza digitale (es. regole di comportamento sulla community online di Scratch)

SACHER Project: A Cloud Platform and Integrated Services for Cultural Heritage and for Restoration

The SACHER project provides a distributed, open source and federated cloud platform able to support the life-cycle management of various kinds of data concerning tangible Cultural Heritage. The paper describes the SACHER platform and, in particular, among the various integrated service prototypes, the most important ones to support restoration processes and cultural asset management: (i) 3D Life Cycle Management for Cultural Heritage (SACHER 3D CH), based on 3D digital models of architecture and dedicated to the management of Cultural Heritage and to the storage of the numerous data generated by the team of professionals involved in the restoration process; (ii) Multidimensional Search Engine for Cultural Heritage (SACHER MuSE CH), an advanced multi-level search system designed to manage Heritage data from heterogeneous sources

Outcome of liver transplantation with grafts from brain-dead donors treated with dual hypothermic oxygenated machine perfusion, with particular reference to elderly donors

Prompted by the utilization of extended criteria donors, dual hypothermic oxygenated machine perfusion (D‐HOPE) was introduced in liver transplantation to improve preservation. When donors after neurological determination of death (DBD) are used, D‐HOPE effect on graft outcomes is unclear. To assess D‐HOPE value in this setting and to identify ideal scenarios for its use, data on primary adult liver transplant recipients from January 2014 to April 2021 were analyzed using inverse probability of treatment weighting, comparing outcomes of D‐HOPE‐treated grafts (n = 121) with those preserved by static cold storage (n = 723). End‐ischemic D‐HOPE was systematically applied since November 2017 based on donor and recipient characteristics and transplant logistics. D‐HOPE use was associated with a significant reduction of early allograft failure (OR: 0.24; 0.83; p = .024), grade ≥3 complications (OR: 0.57; p = .046), comprehensive complication index (−7.20 points; p = .003), and improved patient and graft survival. These results were confirmed in the subset of elderly donors (>75‐year‐old). Although D‐HOPE did not reduce the incidence of biliary complications, its use was associated with a reduced severity of ischemic cholangiopathy. In conclusion, D‐HOPE improves postoperative outcomes and reduces early allograft loss in extended criteria DBD grafts

A Pre-Filtering Approach for Incorporating Contextual Information Into Deep Learning Based Recommender Systems

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To Eat and To Be : food as Differenciation Policy in Spanish America, 16th and 17th Centuries

ABSTRACT: This paper demonstrates that food served as a marker of social differentiation during the 16th and 17th centuries in the Spanish possessions in America, not only in economic terms but also in the sense that food was associated with the social stratum to which a person belonged. Each one was oblidged to eat foods associated with his or her "natural" stratum. This complex hierarchical model of society was based on European patterns coming from the Middle Ages, such as the Great Chain of Being and humoral theory. This model was reinforced in the early modern period, and it took on new characteristics in America, where it was used to differentiate Spaniards, Creoles, Mestizos and Indians.RESUMEN: Este artículo muestra cómo la alimentación servía como un elemento de diferenciación social durante los siglos XVI y XVII, en la América española, no solo como un factor económico, sino asociado a la calidad o estado al que pertenecieran las personas. En este sentido, a cada uno le correspondía comer aquello que era propio de su condición estamental. Este complejo modelo de jerarquización social estaba basado en principios europeos que venían desde la Edad Media, como la gran cadena del ser y la teoría humoral. En la edad moderna, el modelo se reforzó y en América tomó nuevas características, por la forma en que se buscó diferenciar entre españoles, criollos, mestizos e indios

Phenogenomic heterogeneity of post-transplant plasmablastic lymphomas

Plasmablastic lymphoma (PBL) is a rare and clinically aggressive neoplasm that typically occurs in immunocompromised individuals, including those infected with human immunodeficiency virus (HIV) and solid organ allograft recipients. Most prior studies have focused on delineating the clinico-pathological features and genetic attributes of HIVrelated PBL, in which MYC deregulation, Epstein-Barr virus (EBV) infection and, more recently, mutations in JAK/STAT, MAP kinase, and NOTCH pathway genes have been implicated in disease pathogenesis. The phenotypic spectrum of post-transplant (PT)-PBL is not well characterized and data on underlying genetic alterations are limited. This led us to perform comprehensive histopathological and immunophenotypic evaluation and targeted sequencing of 18 samples from 11 patients (8 males, 3 females; age range, 12-76 years) with PT-PBL; eight de novo and three preceded by other types of post-transplant lymphoproliferative disorders. Post-transplant PBL displayed morphological and immunophenotypic heterogeneity and some features overlapped those of plasmablastic myeloma. Six (55%) cases were EBV positive and five (45%) showed MYC rearrangement by fluorescence in situ hybridization. Recurrent mutations in epigenetic regulators (KMT2/MLL family, TET2) and DNA damage repair and response (TP53, mismatch repair genes, FANCA, ATRX), MAP kinase (KRAS, NRAS, HRAS, BRAF), JAK/STAT (STAT3, STAT6, SOCS1), NOTCH (NOTCH1, NOTCH3, SPEN), and immune surveillance (FAS, CD58) pathway genes were observed, with the mutational profiles of EBV+ and EBV– cases exhibiting both similarities and differences. Clinical outcomes also varied, with survival ranging from 0-15.9 years after diagnosis. Besides uncovering the biological heterogeneity of PT-PBL, our study highlights similarities and distinctions between PT-PBL and PBL occurring in other settings and reveals potentially targetable oncogenic pathways in subsets of the disease

International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist