106 research outputs found

    Power Utility Automation Cybersecurity: IEC 61850 Specification of an Intrusion Detection Function

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    International audienceThe IEC 61850 standard defines a global framework for designing power utility automation systems. The main goal of IEC 61850 being interoperability, it brings information and tools for both system modelling and communication architecture. But cybersecurity measures and propositions are scarce. They should be a priority. To help fill this lack of cybersecurity, we specify a fully IEC 61850-compatible intrusion detection function. This paper explains the procedure of defining functions and necessary model objects consistent with the standard requirements. We then detail our intrusion detection function

    A Test bed dedicated to the Study of Vulnerabilities in IEC 61850 Power Utility Automation Networks

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    International audienceIndustrial control systems rely more and more on digital technologies. Although the cyber risk such technologies induce is widely judged as serious, especially for critical infrastructures, these systems have generally not been designed to serve cybersecurity purposes. Instead they were thought first for serving operational efficiency. It thus becomes critical to study cyber threats in industrial environments and experimental test beds are needed to evaluate risks, physical consequences of cyber incidents, and performance of countermeasures. The test bed we present here focuses on studying cyber risks and their mitigation in IEC 61850 power utility automation systems. The operational part is composed of engineering computers, supervision software, off-the-shelf intelligent relays (Intelligent Electronic Device – IED), a hardware-in-the-loop process simulation, and the cybersecurity tools include an attack generation station and a network analyzer. In this paper, we present the operational part, giving details on the power grid hardware-in-the-loop simulation and its importance in the understanding of cyber consequences on the global system. The article concludes giving preliminary experimental results showing consequences of a false data injection attack on a simple electrical architecture

    Architecture des systèmes d'automatisation des postes résiliente aux attaques des trames GOOSE

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    National audienceNotre travail concerne la spécification et la mise en oeuvre d'un système d'automatisation des postes électriques conformes à la norme IEC 61850 capable de fonctionner en présence d'attaques sur les systèmes de communication temps-réel (communication GOOSE). Notre architecture repose sur trois concepts : la réalisation des sondes capables de détecter les attaques sur les trames GOOSE, la remontée des alertes au SCADA et la réalisation d'une commande des équipements de terrain intégrant l'information de cybersécurité

    Corrupted GOOSE Detectors: Anomaly Detection in Power Utility Real-Time Ethernet Communications

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    International audienceGOOSE protocol is used for critical protection operations in the power grid, as standardized by IEC61850. It thus has strong real-time constraints that make very hard to implement any security means for integrity and confidentiality such as encryption or signature. Our answer to this lack of dedicated cybersecurity measures is to check legitimacy of every GOOSE messages flowing over the managed network. When detectors issue an alert, the SCADA informs field devices to discard GOOSE communication and run an alternative protection strategy. This article focuses on the GOOSE attack detectors we developed: one dedicated to Ethernet storm and the other one to fraudulent GOOSE frames. The paper first introduces main GOOSE protocol mechanisms and gives a brief state of the art regarding GOOSE attack management before presenting our architecture and the detectors

    Brain Peroxisomes

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    Peroxisomes are essential organelles in higher eukaryotes as they play a major role in numerous metabolic pathways and redox homeostasis. Some peroxisomal abnormalities, which are often not compatible with life or normal development, were identified in severe demyelinating and neurodegenerative brain diseases. The metabolic roles of peroxisomes, especially in the brain, are described and human brain peroxisomal disorders resulting from a peroxisome biogenesis or a single peroxisomal enzyme defect are listed. The brain abnormalities encountered in these disorders (demyelination, oxidative stress, inflammation, cell death, neuronal migration, differentiation) are described and their pathogenesis are discussed. Finally, the contribution of peroxisomal dysfunctions to the alterations of brain functions during aging and to the development of Alzheimer's disease is considered

    Phenylbutyrate up-regulates the adrenoleukodystrophy-related gene as a nonclassical peroxisome proliferator

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    X-linked adrenoleukodystrophy (X-ALD) is a demyelinating disease due to mutations in the ABCD1 (ALD) gene, encoding a peroxisomal ATP-binding cassette transporter (ALDP). Overexpression of adrenoleukodystrophy-related protein, an ALDP homologue encoded by the ABCD2 (adrenoleukodystrophy-related) gene, can compensate for ALDP deficiency. 4-Phenylbutyrate (PBA) has been shown to induce both ABCD2 expression and peroxisome proliferation in human fibroblasts. We show that peroxisome proliferation with unusual shapes and clusters occurred in liver of PBA-treated rodents in a PPARα-independent way. PBA activated Abcd2 in cultured glial cells, making PBA a candidate drug for therapy of X-ALD. The Abcd2 induction observed was partially PPARα independent in hepatocytes and totally independent in fibroblasts. We demonstrate that a GC box and a CCAAT box of the Abcd2 promoter are the key elements of the PBA-dependent Abcd2 induction, histone deacetylase (HDAC)1 being recruited by the GC box. Thus, PBA is a nonclassical peroxisome proliferator inducing pleiotropic effects, including effects at the peroxisomal level mainly through HDAC inhibition

    Microgliosis: a double-edged sword in the control of food intake

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    Maintaining energy balance is essential for survival and health. This physiological function is controlled by the brain, which adapts food intake to energy needs. Indeed, the brain constantly receives a multitude of biological signals that are derived from digested foods or that originate from the gastrointestinal tract, energy stores (liver and adipose tissues) and other metabolically active organs (muscles). These signals, which include circulating nutrients, hormones and neuronal inputs from the periphery, collectively provide information on the overall energy status of the body. In the brain, several neuronal populations can specifically detect these signals. Nutrient-sensing neurons are found in discrete brain areas and are highly enriched in the hypothalamus. In turn, specialized brain circuits coordinate homeostatic responses acting mainly on appetite, peripheral metabolism, activity and arousal. Accumulating evidence shows that hypothalamic microglial cells located at the vicinity of these circuits can influence the brain control of energy balance. However, microglial cells could have opposite effects on energy balance, that is homeostatic or detrimental, and the conditions for this shift are not totally understood yet. One hypothesis relies on the extent of microglial activation, and nutritional lipids can considerably change it

    Immune response of BV-2 microglial cells is impacted by peroxisomal beta-oxidation

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    Microglia are crucial for brain homeostasis, and dysfunction of these cells is a key driver in most neurodegenerative diseases, including peroxisomal leukodystrophies. In X-linked adrenoleukodystrophy (X-ALD), a neuroinflammatory disorder, very long-chain fatty acid (VLCFA) accumulation due to impaired degradation within peroxisomes results in microglial defects, but the underlying mechanisms remain unclear. Using CRISPR/Cas9 gene editing of key genes in peroxisomal VLCFA breakdown (Abcd1, Abcd2, and Acox1), we recently established easily accessible microglial BV-2 cell models to study the impact of dysfunctional peroxisomal β-oxidation and revealed a disease-associated microglial-like signature in these cell lines. Transcriptomic analysis suggested consequences on the immune response. To clarify how impaired lipid degradation impacts the immune function of microglia, we here used RNA-sequencing and functional assays related to the immune response to compare wild-type and mutant BV-2 cell lines under basal conditions and upon pro-inflammatory lipopolysaccharide (LPS) activation. A majority of genes encoding proinflammatory cytokines, as well as genes involved in phagocytosis, antigen presentation, and co-stimulation of T lymphocytes, were found differentially overexpressed. The transcriptomic alterations were reflected by altered phagocytic capacity, inflammasome activation, increased release of inflammatory cytokines, including TNF, and upregulated response of T lymphocytes primed by mutant BV-2 cells presenting peptides. Together, the present study shows that peroxisomal β-oxidation defects resulting in lipid alterations, including VLCFA accumulation, directly reprogram the main cellular functions of microglia. The elucidation of this link between lipid metabolism and the immune response of microglia will help to better understand the pathogenesis of peroxisomal leukodystrophies
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