1,459 research outputs found

    A Taxonomy of Phishing: Attack Types Spanning Economic, Temporal, Breadth, and Target Boundaries

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    Phishing remains a pernicious problem for organizations. Phishing attacks are increasing in sophistication, which hinders the ability of cybersecurity functions to effectively defend against them. These attacks are becoming increasingly complex, dynamic, and multifaceted to evade the organizational, individual, and technical countermeasures employed in a cybersecurity ecosystem. Information security (ISec) phishing research and practice have provided an understanding of generalized phishing attacks and their subsequent defense. Yet by applying generalized phishing rules to these studies, it may not be sufficient to understand and defend escalated forms of phishing. This study seeks to develop a taxonomy of phishing to provide a more nuanced understanding of this phenomena. This taxonomy may assist ISec research in providing theoretical guidance for the understanding and defense of the various forms of phishing

    Catalytic Kinetic Resolution of a Dynamic Racemate: Highly Stereoselective Ī²-Lactone Formation by N-Heterocyclic Carbene Catalysis

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    This study describes the combined experimental and computational elucidation of the mechanism and origins of stereoselectivities in the NHC-catalyzed dynamic kinetic resolution (DKR) of Ī±-substituted-Ī²-ketoesters. Density functional theory computations reveal that the NHC-catalyzed DKR proceeds by two mechanisms, depending on the stereochemistry around the forming bond: 1) a concerted, asynchronous formal (2+2) aldol-lactonization process, or 2) a stepwise spiro-lactonization mechanism where the alkoxide is trapped by the NHC-catalyst. These mechanisms contrast significantly from mechanisms found and postulated in other related transformations. Conjugative stabilization of the electrophile and non-classical hydrogen bonds are key in controlling the stereoselectivity. This reaction constitutes an interesting class of DKRs in which the catalyst is responsible for the kinetic resolution to selectively and irreversibly capture an enantiomer of a substrate undergoing rapid racemization with the help of an exogenous base

    Potential of known and short prokaryotic protein motifs as a basis for novel peptide-based antibacterial therapeutics: a computational survey

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    Short linear motifs (SLiMs) are functional stretches of protein sequence that are of crucial importance for numerous biological processes by mediating proteinā€“protein interactions. These motifs often comprise peptides of less than 10 amino acids that modulate proteinā€“protein interactions. While well-characterized in eukaryotic intracellular signaling, their role in prokaryotic signaling is less well-understood. We surveyed the distribution of known motifs in prokaryotic extracellular and virulence proteins across a range of bacterial species and conducted searches for novel motifs in virulence proteins. Many known motifs in virulence effector proteins mimic eukaryotic motifs and enable the pathogen to control the intracellular processes of their hosts. Novel motifs were detected by finding those that had evolved independently in three or more unrelated virulence proteins. The search returned several significantly over-represented linear motifs of which some were known motifs and others are novel candidates with potential roles in bacterial pathogenesis. A putative C-terminal G[AG].motiffoundintypeIVsecretionsystemproteinswasamongthemostsignificantdetected.AKK motif found in type IV secretion system proteins was among the most significant detected. A KK motif that has been previously identified in a plasminogen-binding protein, was demonstrated to be enriched across a number of adhesion and lipoproteins. While there is some potential to develop peptide drugs against bacterial infection based on bacterial peptides that mimic host components, this could have unwanted effects on host signaling. Thus, novel SLiMs in virulence factors that do not mimic host components but are crucial for bacterial pathogenesis, such as the type IV secretion system, may be more useful to develop as leads for anti-microbial peptides or drugs

    Deicing Composition

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    A deicing composition is provided. The composition includes a potassium or sodium salt of a carboxylic acid and a lithium salt of a carboxylic acid or lithium nitrate, wherein the molar ratio of lithium to potassium or lithium to sodium is from 10 percent to 80 percent

    Deicing composition

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    A deicing composition is provided. The composition includes a potassium or sodium salt of a carboxylic acid and a lithium salt of a carboxylic acid or lithium nitrate, wherein the molar ratio of lithium to potassium or lithium to sodium is from 10 percent to 80 percent

    Microevolutionary traits and comparative population genomics of the emerging pathogenic fungus Cryptococcus gattii

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    Emerging fungal pathogens cause an expanding burden of disease across the animal kingdom, including a rise in morbidity and mortality in humans. Yet, we currently have only a limited repertoire of available therapeutic interventions. A greater understanding of the mechanisms of fungal virulence and of the emergence of hypervirulence within species is therefore needed for new treatments and mitigation efforts. For example, over the past decade, an unusual lineage of Cryptococcus gattii, which was first detected on Vancouver Island, has spread to the Canadian mainland and the Pacific Northwest infecting otherwise healthy individuals. The molecular changes that led to the development of this hypervirulent cryptococcal lineage remain unclear. To explore this, we traced the history of similar microevolutionary events that can lead to changes in host range and pathogenicity. Here, we detail fine-resolution mapping of genetic differences between two highly related Cryptococcus gattii VGIIc isolates that differ in their virulence traits (phagocytosis, vomocytosis, macrophage death, mitochondrial tubularization and intracellular proliferation). We identified a small number of single site variants within coding regions that potentially contribute to variations in virulence. We then extended our methods across multiple lineages of C. gattii to study how selection is acting on key virulence genes within different lineages. This article is part of the themed issue ā€˜Tackling emerging fungal threats to animal health, food security and ecosystem resilienceā€™
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