Luca Sterpone

Bio: Luca Sterpone is an academic researcher from Polytechnic University of Turin. The author has contributed to research in topics: Fault injection & Field-programmable gate array. The author has an hindex of 24, co-authored 222 publications receiving 3125 citations. Previous affiliations of Luca Sterpone include Instituto Politécnico Nacional.

Functional Failure Rate Due to Single-Event Transients in Clock Distribution Networks

Abstract: With technology scaling, lower supply voltages, and higher operating frequencies clock distribution networks become more and more vulnerable to transients faults. These faults can cause circuit-wide effects and thus, significantly contribute to the functional failure rate of the circuit. This paper proposes a methodology to analyse how the functional behaviour is affected by Single-Event Transients in the clock distribution network. The approach is based on logic-level simulation and thus, only uses the register-transfer level description of a design. Therefore, a fault model is proposed which implements the main effects due to radiation-induced transients in the clock network. This fault model enables the computation of the functional failure rate caused by Single-Event Transients for each individual clock buffer, as well as the complete network. Further, it allows the identification of the most vulnerable flip-flops related to Single-Event Transients in the clock network. The proposed methodology is applied in a practical example and a fault injection campaign is performed. In order to evaluate the impact of Single-Event Transients in clock distribution networks, the obtained functional failure rate is compared to the error rate caused by Single-Event Upsets in the sequential logic.

On the development of diagnostic test programs for VLIW processors

Abstract: Software-Based Self-Test (SBST) approaches have shown to be an effective solution to detect permanent faults, both at the end of the production process, and during the operational phase. When partial reconfiguration is adopted to deal with permanent faults, we also need to identify the faulty module, which is then substituted with a spare one. Software-based Diagnosis techniques can be exploited for this purpose, too. When Very Long Instruction Word (VLIW) processors are addressed, these techniques can effectively exploit the parallelism intrinsic in these architectures. In this paper we propose a new approach that starting from existing detection-oriented programs generates a diagnosis-oriented test program which in most cases is able to identify the faulty module. Experimental results gathered on a case study show the effectiveness of the proposed approach.

A new software tool for static analysis of SET sensitiveness in Flash-based FPGAs

Abstract: The higher resiliency of Flash-based FPGAs to Single Event Upsets (SEUs) with respect to other non radiation-hardened devices, such as SRAM-based FPGAs, are increasing more and more their demand for avionic and space applications, where a harsh environment rich in ionizing radiation has to be faced. In this type of devices other transient faults tend to dominate over SEUs, especially when the device operates at high frequency. In this scenario, it is expected that Single Event Transient (SET) faults will predominate. As a result, designers will still need prediction techniques to forecast the effects of ionizing radiation in their designs. Although radiation testing is a feasible method for evaluating circuit sensitiveness against SETs, it is hard to implement, very expensive, and it can be used only in later phases of the design process, when a prototype of the system is available. On the other hand, simulation techniques need a first technology characterization step and also require a very detailed model for being effective; moreover they are application dependent. In this paper we propose a new software tool for analyzing designs implemented in Flash-based FPGAs and estimating SET sensitiveness. The evaluation process is static, as it does not entail any simulation. In particular, it provides worst-case results, thus being intrinsically more conservative than other dynamic methods. Experimental results are presented comparing the ones coming from radiation testing and the results provided by the presented tool. They validate the proposed approach.

System-Level Considerations

Abstract: In the previous chapters we presented the impact of ionizing radiation on FPGA devices; we discussed the possible mitigation techniques looking at both the FPGA manufacturer point of view and the FPGA user point of view; we also presented experimental data about reprogrammable FPGAs available on the market; and we discussed the use of application-level techniques to mitigate ionizing radiation effects on several case studies.

Biological properties of extracellular vesicles and their physiological functions

Abstract: In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive investigation has targeted the role of EVs in different pathological processes, for example, in cancer and autoimmune diseases, the EV-mediated maintenance of homeostasis and the regulation of physiological functions have remained less explored. Here, we provide a comprehensive overview of the current understanding of the physiological roles of EVs, which has been written by crowd-sourcing, drawing on the unique EV expertise of academia-based scientists, clinicians and industry based in 27 European countries, the United States and Australia. This review is intended to be of relevance to both researchers already working on EV biology and to newcomers who will encounter this universal cell biological system. Therefore, here we address the molecular contents and functions of EVs in various tissues and body fluids from cell systems to organs. We also review the physiological mechanisms of EVs in bacteria, lower eukaryotes and plants to highlight the functional uniformity of this emerging communication system.

Extracellular vesicles: biology and emerging therapeutic opportunities

Abstract: Within the past decade, extracellular vesicles have emerged as important mediators of intercellular communication, being involved in the transmission of biological signals between cells in both prokaryotes and higher eukaryotes to regulate a diverse range of biological processes. In addition, pathophysiological roles for extracellular vesicles are beginning to be recognized in diseases including cancer, infectious diseases and neurodegenerative disorders, highlighting potential novel targets for therapeutic intervention. Moreover, both unmodified and engineered extracellular vesicles are likely to have applications in macromolecular drug delivery. Here, we review recent progress in understanding extracellular vesicle biology and the role of extracellular vesicles in disease, discuss emerging therapeutic opportunities and consider the associated challenges.

Atheroprotective communication between endothelial cells and smooth muscle cells through miRNAs.

Abstract: The shear-responsive transcription factor Kruppel-like factor 2 (KLF2) is a critical regulator of endothelial gene expression patterns induced by atheroprotective flow. As microRNAs (miRNAs) post-transcriptionally control gene expression in many pathogenic and physiological processes, we investigated the regulation of miRNAs by KLF2 in endothelial cells. KLF2 binds to the promoter and induces a significant upregulation of the miR-143/145 cluster. Interestingly, miR-143/145 has been shown to control smooth muscle cell (SMC) phenotypes; therefore, we investigated the possibility of transport of these miRNAs between endothelial cells and SMCs. Indeed, extracellular vesicles secreted by KLF2-transduced or shear-stress-stimulated HUVECs are enriched in miR-143/145 and control target gene expression in co-cultured SMCs. Extracellular vesicles derived from KLF2-expressing endothelial cells also reduced atherosclerotic lesion formation in the aorta of ApoE(-/-) mice. Combined, our results show that atheroprotective stimuli induce communication between endothelial cells and SMCs through an miRNA- and extracellular-vesicle-mediated mechanism and that this may comprise a promising strategy to combat atherosclerosis.