685 research outputs found

    Vulnerability analysis of satellite-based synchronized smart grids monitoring systems

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    The large-scale deployment of wide-area monitoring systems could play a strategic role in supporting the evolution of traditional power systems toward smarter and self-healing grids. The correct operation of these synchronized monitoring systems requires a common and accurate timing reference usually provided by a satellite-based global positioning system. Although these satellites signals provide timing accuracy that easily exceeds the needs of the power industry, they are extremely vulnerable to radio frequency interference. Consequently, a comprehensive analysis aimed at identifying their potential vulnerabilities is of paramount importance for correct and safe wide-area monitoring system operation. Armed with such a vision, this article presents and discusses the results of an experimental analysis aimed at characterizing the vulnerability of global positioning system based wide-area monitoring systems to external interferences. The article outlines the potential strategies that could be adopted to protect global positioning system receivers from external cyber-attacks and proposes decentralized defense strategies based on self-organizing sensor networks aimed at assuring correct time synchronization in the presence of external attacks

    Using genetic data to predict the vulnerability of a native predator to a toxic invader

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    Australia has no native toad species, and as a consequence, many Australian predators lack resistance to the toxins of the invasive cane toad Rhinella marina, and die if they ingest one of these toads. Resistance is conferred by a small and consistent genetic change, so genetic data can provide a rapid, non-invasive way to clarify the vulnerability of as-yet-unstudied taxa. To evaluate the hypothesis that a recent decline of ghost bat Macroderma gigas populations in tropical Australia is due to ingestion of cane toads, we sequenced the H1-H2 extracellular domain of the sodium-potassium-ATPase. Two anuran-eating Asian relatives of the Australian species possess the genes that confer bufotoxin resistance, but the ghost bat does not. Like varanid lizards (major victims of the toad invasion), Australian ghost bats appear to have lost their physiological resistance to toad toxins but retained generalist foraging behaviours, potentially including a readiness to attack toads as well as frogs. Our genetic data suggest that cane toads may imperil populations of this iconic predator, and detailed behavioural and ecological studies are warranted.Richard Shine, Supen Wang, George Madani, Kyle N. Armstrong, Libiao Zhang, Yi-Ming L

    Managing Forest Conflicts: Perspectives of Indonesia's Forest Management Unit Directors

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    Recent expansion of the forestry and plantation sectors in Indonesia has intensified agrarian and natural resource conflicts, and created increased awareness of the social, economic and environmental impacts of these disputes. Addressing these disputes is a critical issue in advancing Indonesia's commitment to sustainable forest management. The Forest Management Units (Kesatuan Pengelolaan Hutan, or KPH), have become the pivotal structural element for managing all state forests at the local level, with responsibility for conventional forest management and policy implementation (establishing management boundaries, conducting forest inventory, and developing forest management plans), as well as the legal mandate to communicate and work with indigenous people and local communities. This paper presents the results of a national survey of all currently functioning KPH units, the first of its kind ever conducted with KPH leadership, to obtain a system-wide perspective of the KPHs' role, mandate, and capacity for serving as effective intermediaries in managing forest conflicts in Indonesia. The survey results show that the KPHs are still in a very initial stage of development, and are struggling with a complex and rapidly evolving policy and institutional framework. The most common conflicts noted by respondents included forest encroachment, tenure disputes, boundary conflicts, and illegal logging and land clearing. KPH leadership views conflict resolution as among their primary duties and functions, and underscored the importance of more proactive and collaborative approaches for addressing conflict, many seeing themselves as capable facilitators and mediators. Overall, these results juxtapose a generally constructive view by KPH leadership over their role and responsibility in addressing forest management conflicts, with an extremely challenging social, institutional, and political setting. The KPHs can certainly play an important role as local intermediaries, and in some cases, as facilitative mediators in resolving local conflicts, but only with a more concerted effort from central and provincial government authorities to provide greater consistency in policies and regulations, improved policy communication, and a sustained commitment to strengthening the capacity of individual KPHs

    MODELISATION DE L'INFLUENCE DU TRAITEMENT THERMIQUE SUR LES PROPRIETES MECANIQUES DES ALLIAGES ALUMINIUM-CUIVRE (Al-Cu)

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    In order to master and improve the quality and properties of the final products, the major industrial challenge lies in the possibility of controlling the morphology, size of microstructures that reside within the molded pieces, as well as their defects; this is the fundamental reason according to which we are more and more interested in mastering the growth and germination of such alloys, as well as the developing structures, at the time of solidification process. The modeling reveals as a valuable aid in the mastery of the formation of such heterogeneousness: segregation cells that are incompatible with industrial requirements. The whole work focuses upon the modeling of the segregation phenomenon of the four hypoeutectic alloys, Al1%Cu, Al2%Cu, Al3%Cu et Al4%Cu, as well as the copper effect upon certain mechanical properties of aluminum. Usually, the microstructure and mechanical behavior of such alloys as Al-Cu are directly influenced by some parameters such as composition, cooling velocity and homogenization process

    Interactions in vivo between the Vif protein of HIV-1 and the precursor (Pr55GAG) of the virion nucleocapsid proteins

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    The abnormality of viral core structure seen in vif-defective HIV-1 grown in PBMCs has suggested a role for Vif in viral morphogenesis. Using an in vivo mammalian two-hybrid assay, the interaction between Vif and the precursor (Pr55GAG) of the virion nucleocapsid proteins has been analysed. This revealed the amino-terminal (aa 1–22) and central (aa 70–100) regions of Vif to be essential for its interaction with Pr55GAG, but deletion of the carboxy-terminal (aa 158–192) region of the protein had only a minor effect on its interaction. Initial deletion studies carried out on Pr55GAG showed that a 35-amino-acid region of the protein bridging the MA(p17)–CA(p24) junction was essential for its ability to interact with Vif. Site-directed mutagenesis of a conserved tryptophan (Trp21) near the amino terminus of Vif showed it to be important for the interaction with Pr55GAG. By contrast, mutagenesis of the highly conserved YLAL residues forming part of the BC-box motif, shown to be important in Vif promoting degradation of APOBEC3G/3F, had little or no effect on the Vif–Pr55GAG interaction

    Ipsilateral reexpansion pulmonary edema after drainage of a spontaneous pneumothorax: a case report

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    We report a case of ipsilateral reexpansion pulmonary edema occurring after the insertion of a chest tube in a patient with spontaneous pneumothorax. The patient received supplemental oxygen via a non-rebreather face mask to compensate for hypoxemia. 24 hours after the acute event, the patient recovered completely without residual hypoxemia. Reexpansion pulmonary edema after the insertion of a thoracic drainage for pneumothorax or pleural effusion is a rare complication with a high mortality rate up to 20%. It should be considered in case of hypoxemia following the insertion of a chest tube. The exact pathophysiology leading to this complication is not known. Risk factors for reexpansion pulmonary edema should be evaluated and considered prior to the insertion of chest tubes. Treatment is supportive

    Carbon nanomaterials for targeted cancer therapy drugs: a critical review.

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    Cancer represents one of the main causes of human death in developed countries. Most current therapies, unfortunately, carry a number of side effects, such as toxicity and damage to healthy cells, as well as the risk of resistance and recurrence. Therefore, cancer research is trying to develop therapeutic procedures with minimal negative consequences. The use of nanomaterial-based systems appears to be one of them. In recent years, great progress has been made in the field of possible use of nanomaterials with high potential in biomedical applications. Carbon nanomaterials, thanks to their unique physicochemical properties, are gaining more and more popularity in cancer therapy. They are valued especially for their ability to deliver drugs or small therapeutic molecules to these cells. Through surface functionalization, they can specifically target tumor tissues, increasing the therapeutic potential and significantly reducing the adverse effects of therapy. Their potential future use could, therefore, as vehicles for drug delivery. This review presents the latest findings of research studies using carbon nanomaterials in the treatment of various types of cancer. To carry out this study, different databases such as Web of Science, PubMed, MEDLINE and Google Scholar were employed. The findings of research studies chosen from more than 2000 viewed scientific publications from the last 15 years were compared

    Dietary soy and meat proteins induce distinct physiological and gene expression changes in rats

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    This study reports on a comprehensive comparison of the effects of soy and meat proteins given at the recommended level on physiological markers of metabolic syndrome and the hepatic transcriptome. Male rats were fed semi-synthetic diets for 1 wk that differed only regarding protein source, with casein serving as reference. Body weight gain and adipose tissue mass were significantly reduced by soy but not meat proteins. The insulin resistance index was improved by soy, and to a lesser extent by meat proteins. Liver triacylglycerol contents were reduced by both protein sources, which coincided with increased plasma triacylglycerol concentrations. Both soy and meat proteins changed plasma amino acid patterns. The expression of 1571 and 1369 genes were altered by soy and meat proteins respectively. Functional classification revealed that lipid, energy and amino acid metabolic pathways, as well as insulin signaling pathways were regulated differently by soy and meat proteins. Several transcriptional regulators, including NFE2L2, ATF4, Srebf1 and Rictor were identified as potential key upstream regulators. These results suggest that soy and meat proteins induce distinct physiological and gene expression responses in rats and provide novel evidence and suggestions for the health effects of different protein sources in human diets

    Increase the strength characteristics of polymer films by radiation graft polymerization

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    The possibility of increasing the strength characteristics of polymer films based on polyethylene and polyamide by radiation graft polymerization was investigated. Two methods of graft polymerization (direct method and the method of polymer mixtures cross-linking) on the PMMA films surface were studied. The possibility of increasing the strength and elasticity of polymeric films by radiation modification of polymethyl methacrylate was shown
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