1,233 research outputs found

    Optimizing Cybersecurity Budgets with AttackSimulation

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    Modern organizations need effective ways to assess cybersecurity risk. Successful cyber attacks can result in data breaches, which may inflict significant loss of money, time, and public trust. Small businesses and non-profit organizations have limited resources to invest in cybersecurity controls and often do not have the in-house expertise to assess their risk. Cyber threat actors also vary in sophistication, motivation, and effectiveness. This paper builds on the previous work of Lerums et al., who presented an AnyLogic model for simulating aspects of a cyber attack and the efficacy of controls in a generic enterprise network. This paper argues that their model is an effective quantitative means of measuring the probability of success of a threat actor and implements two primary changes to increase the model\u27s accuracy. First, the authors modified the model\u27s inputs, allowing users to select threat actors based on the organization\u27s specific threat model. Threat actor effectiveness is evaluated based on publicly available breach data (in addition to security control efficacy), resulting in further refined attack success probabilities. Second, all three elements - threat effectiveness, control efficacy, and model variance - are computed and evaluated at each node to increase the estimation fidelity in place of pooled variance calculations. Visualization graphs, multiple simulation runs (up to 1 million), attack path customization, and code efficiency changes are also implemented. The result is a simulation tool that provides valuable insight to decision-makers and practitioners about where to most efficiently invest resources in their computing environment to increase cybersecurity posture. AttackSimulation and its source code are freely available on GitHub

    Multiple sulphur and iron isotope composition of detrital pyrite in Archaean sedimentary rocks : a new tool for provenance analysis

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    Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 286 (2009): 436-445, doi:10.1016/j.epsl.2009.07.008.Multiple S (δ34S and δ33S) and Fe (δ56Fe) isotope analyses of rounded pyrite grains from 3.1 to 2.6 Ga conglomerates of southern Africa indicate their detrital origin, which supports anoxic surface conditions in the Archaean. Rounded pyrites from Meso- to Neoarchaean gold and uranium-bearing strata of South Africa are derived from both crustal and sedimentary sources, the latter being characterised by non-mass dependent fractionation of S isotopes (Δ33S as negative as -1.35‰) and large range of Fe isotope values (δ56Fe between -1.1 and 1.2‰). Most sediment-sourced pyrite grains are likely derived from sulphide nodules in marine organic matter-rich shales, sedimentary exhalites and volcanogenic massive sulphide deposits. Some sedimentary pyrite grains may have been derived from in situ sulphidised Fe-oxides, prior to their incorporation into the conglomerates, as indicated by unusually high positive δ56Fe values. Sedimentary sulphides without significant non-mass dependent fractionation of S isotopes were also present in the source of some conglomerates. The abundance in these rocks of detrital pyrite unstable in the oxygenated atmosphere may suggest factors other than high pO2 as the cause for the absence of significant non-mass dependent fractionation processes in the 3.2 – 2.7 Ga atmosphere. Rounded pyrites from the ca. 2.6 Ga conglomerates of the Belingwe greenstone belt in Zimbabwe have strongly fractionated δ34S, Δ33S and δ56Fe values, the source of which can be traced back to black shale-hosted massive sulphides in the underlying strata. The study demonstrates the utility of combined multiple S and Fe isotope analysis for provenance reconstruction of Archaean sedimentary successions.AH acknowledges support by NAI International Collaboration Grant and NRF grant FA2005040400027. AB participation was supported by NSF grant EAR-937 05-45484, NAI award No. NNA04CC09A, and NSERC 938 Discovery grant. Rouxel's contribution was supported by NSF OCE-0622982

    Analisis Hasil Pemeriksaan Spesimen Darah Penderita Demam Berdarah Dengue di Jakarta Tahun 1988

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    Dengue Haemorrhagic Fever is an endemic and important public health disease in Indonesia. Surveillance of hospitalized case usually reported 5.000 cases annually but 10.000 cases could be reported during an outbreak period. The case fatality rate had been decreasing to 4% at present. Studies to analyse the risk factors of an area, pathophysiology of shock or bleeding, prevention, eradication and surveillance were still needed. The important Dengue Haemorrhagic Fever factors were analysed in this tudy based on the 1756 specimens tested in the Communicable Disease Research Center during the period from January1988 to Desember 1988, sent by most of the hospitals in Jakarta. The overall difference between male and female was not significant, although on January, July, September and Desember 1988 females were almost 2 times higher then males.Theoverall difference of children and adult groups were also not significant, although on February, March, November and Decem­ber 1988 adults were higher 2-5 times then children. This findings were not usual. The antibody response titers during acute and convalescence period of illness was lower among chil­dren. These findings were not usual. The antibody response titers during acute and convalescence period of illness was lower among chil­dren then adults, although it was still lower then in Thailand

    OPPORTUNISTIC POLYGYNY IN THE LOUISIANA WATERTHRUSH

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    Limits To The Use Of Threatened Species Lists

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    Threatened species lists are designed primarily to provide an easily understood qualitative estimate of risk of extinction. Although these estimates of risk can be accurate, the lists have inevitably become linked to several decision-making processes. There are four ways in which such lists are commonly used: to set priorities for resource allocation for species recovery; to inform reserve system design; to constrain development and exploitation; and to report on the state of the environment. The lists were not designed for any one of these purposes, and consequently perform some of them poorly. We discuss why, if and how they should be used to achieve these purposes

    Genomic analysis of early murine mammary gland development using novel probe-level algorithms

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    We describe a novel algorithm (ChipStat) for detecting gene-expression changes utilizing probe-level comparisons of replicate Affymetrix oligonucleotide microarray data. A combined detection approach is shown to yield greater sensitivity than a number of widely used methodologies including SAM, dChip and logit-T. Using this approach, we identify alterations in functional pathways during murine neonatal-pubertal mammary development that include the coordinate upregulation of major urinary proteins and the downregulation of loci exhibiting reciprocal imprinting

    Towards the development of an Inter-Cultural Scale to Measure Trust in Automation

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    Trust is conceived as an attitude leading to intentions resulting in user actions involving automation. It is generally believed that trust is dynamic and that a user’s prior experience with automation affects future behavior indirectly through causing changes in trust. Additionally, individual differences and cultural factors have been frequently cited as the contributors to influencing trust beliefs about using and monitoring automation. The presented research focuses on modeling human’s trust when interacting with automated systems across cultures. The initial trust assessment instrument, comprising 110 items along with 2 perceptions (general vs. specific use of automation), has been empirically validated. Detailed results comparing items and dimensionality with our new pooled measure will be presented

    Ancient DNA sheds light on the genetic origins of early Iron Age Philistines

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    The ancient Mediterranean port city of Ashkelon, identified as “}Philistine{”} during the Iron Age, underwent a marked cultural change between the Late Bronze and the early Iron Age. It has been long debated whether this change was driven by a substantial movement of people, possibly linked to a larger migration of the so-called {“}Sea Peoples.{” Here, we report genome-wide data of 10 Bronze and Iron Age individuals from Ashkelon. We find that the early Iron Age population was genetically distinct due to a European-related admixture. This genetic signal is no longer detectible in the later Iron Age population. Our results support that a migration event occurred during the Bronze to Iron Age transition in Ashkelon but did not leave a long-lasting genetic signature

    A novel acetyl xylan esterase enabling complete deacetylation of substituted xylans

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    Background: Acetylated 4-O-(methyl) glucuronoxylan (GX) is the main hemicellulose in deciduous hardwood, and comprises a beta-(1 -> 4)-linked xylopyranosyl (Xylp) backbone substituted by both acetyl groups and alpha-(1 -> 2)-linked 4-O-methylglucopyranosyluronic acid (MeGlcpA). Whereas enzymes that target singly acetylated Xylp or doubly 2,3-O-acetyl-Xylp have been well characterized, those targeting (2-O-MeGlcpA) 3-O-acetyl-Xylp structures in glucuronoxylan have remained elusive. Results: An unclassified carbohydrate esterase (FjoAcXE) was identified as a protein of unknown function from a polysaccharide utilization locus (PUL) otherwise comprising carbohydrate-active enzyme families known to target xylan. FjoAcXE was shown to efficiently release acetyl groups from internal (2-O-MeGlcpA) 3-O-acetyl-Xylp structures, an activity that has been sought after but lacking in known carbohydrate esterases. FjoAcXE action boosted the activity of alpha-glucuronidases from families GH67 and GH115 by five and nine times, respectively. Moreover, FjoAcXE activity was not only restricted to GX, but also deacetylated (3-O-Araf)2-O-acetyl-Xylp of feruloylated xylooligomers, confirming the broad substrate range of this new carbohydrate esterase. Conclusion: This study reports the discovery and characterization of the novel carbohydrate esterase, FjoAcXE. In addition to cleaving singly acetylated Xylp, and doubly 2,3-O-acetyl-Xylp, FjoAcXE efficiently cleaves internal 3-O-acetyl-Xylp linkages in (2-O-MeGlcpA)3-O-acetyl-Xylp residues along with densely substituted and branched xylooligomers; activities that until now were missing from the arsenal of enzymes required for xylan conversion.Peer reviewe
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