37 research outputs found

    Research Trends in Cybercrime and Cybersecurity: A Review Based on Web of Science Core Collection Database

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    Studies on cybercrime and cybersecurity have expanded in both scope and breadth in recent years. This study offers a bibliometric review of research trends in cybercrime and cybersecurity over the past 26 years (1995-2021) based on Web of Science core collection database. Specifically, we examine the growth of scholarship and the expanded scope of subject categories and relevant journals. We also analyze the research collaboration network based on authors’ affiliated institutions and countries. Finally, we identify major topics within the fields, how each topic relates to – and diverges from – one another, and their evolution over time. Overall, we illustrate the scientific landscape of cybercrime and cybersecurity scholarship by quantitatively synthesizing major components of existing literature. This study offers actionable insights to help researchers identify key research resources, establish/expand collaboration networks, and investigate emerging research topics in this increasingly important domain in criminology and criminal justice

    Dating North Pacific Abyssal Sediments by Geomagnetic Paleointensity: Implications of Magnetization Carriers, Plio-Pleistocene Climate Change, and Benthic Redox Conditions

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    Non-carbonaceous abyssal fine-grained sediments cover vast parts of the North Pacific’s deep oceanic basins and gain increasing interests as glacial carbon traps. They are, however, difficult to date at an orbital-scale temporal resolution and still rarely used for paleoceanographic reconstructions. Here, we show that sedimentary records of past geomagnetic field intensity have high potential to improve reversal-based magnetostratigraphic age models. Five sediment cores from Central North Pacific mid-latitudes (39–47°N) and abyssal water depths ranging from 3,900 to 6,100 m were cube-sampled at 23 mm resolution and analyzed by automated standard paleo- and rock magnetic methods, XRF scanning, and electron microscopy. Relative Paleointensity (RPI) records were determined by comparing natural vs. anhysteretic remanent magnetization losses during alternating field demagnetization using a slope method within optimized coercivity windows. The paleomagnetic record delivered well interpretable geomagnetic reversal sequences back to 3 Ma. This age span covers the climate-induced transition from a biogenic magnetite prevalence in the Late Pliocene and Early Pleistocene to a dust-dominated detrital magnetic mineral assemblage since the Mid-Pleistocene. Volcaniclastic materials from concurrent eruptions and gravitational or contouritic sediment re-deposition along extinct seamount flanks provide a further important source of fine- to coarse-grained magnetic carriers. Surprisingly, higher proportions of biogenic vs. detrital magnetite in the late Pliocene correlate with systematically lowered RPI values, which seems to be a consequence of magnetofossil oxidation rather than reductive depletion. Our abyssal RPI records match the astronomically tuned stack of the mostly bathyal Pacific RPI records. While a stratigraphic correlation of rock magnetic and element ratio logs with standard oxygen isotope records was sporadically possible, the RPI minima allowed to establish further stratigraphic tie points at ∼50 kyr intervals. Thus, this RPI-enhanced magnetostratigraphy appears to be a major step forward to reliably date unaltered abyssal North Pacific sediments close to orbital-scale resolution

    Performance of the FOS and GHRS Pt/(Cr)-Ne Hollow-cathode Lamps after their Return from Space and Comparison with Archival Data

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    The Space Telescope European Coordinating Facility (ST-ECF) and National Institute of Standards and Technology (NIST) are collaborating to study hollow cathode calibration lamps as used onboard the Hubble Space Telescope (HST). As part of the STIS Calibration Enhancement (STIS-CE) Project we are trying to improve our understanding of the performance of hollow cathode lamps and the physical processes involved in their long term operation. The original flight lamps from the Faint Object Spectrograph (FOS) and the Goddard High Resolution Spectrograph (GHRS) are the only lamps that have ever been returned to Earth after extended operation in space. We have taken spectra of all four lamps using NIST s 10.7-m normal-incidence spectrograph and Fourier transform spectrometer (FTS) optimized for use in the ultraviolet (UV). These spectra, together with spectra archived from six years of on-orbit operations and pre-launch spectra, provide a unique data set - covering a period of about 20 years - for studying aging effects in these lamps. Our findings represent important lessons for the choice and design of calibration sources and their operation in future UV and optical spectrographs in space

    A Multidisciplinary Approach to Investigate Deep-Pelagic Ecosystem Dynamics in the Gulf of Mexico Following Deepwater Horizon

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    The pelagic Gulf of Mexico (GoM) is a complex system of dynamic physical oceanography (western boundary current, mesoscale eddies), high biological diversity, and community integration via diel vertical migration and lateral advection. Humans also heavily utilize this system, including its deep-sea components, for resource extraction, shipping, tourism, and other commercial activity. This utilization has had impacts, some with disastrous consequences. The Deepwater Horizon oil spill (DWHOS) occurred at a depth of ∼1500 m (Macondo wellhead), creating a persistent and toxic mixture of hydrocarbons and dispersant in the deep-pelagic (water column below 200 m depth) habitat. In order to assess the impacts of the DWHOS on this habitat, two large-scale research programs, described herein, were designed and executed. These programs, ONSAP and DEEPEND, aimed to quantitatively characterize the oceanic ecosystem of the northern GoM and to establish a time-series with which natural and anthropogenic changes could be detected. The approach was multi-disciplinary in nature and included in situ sampling, acoustic sensing, water column profiling and sampling, satellite remote sensing, AUV sensing, numerical modeling, genetic sequencing, and biogeochemical analyses. The synergy of these methodologies has provided new and unprecedented perspectives of an oceanic ecosystem with respect to composition, connectivity, drivers, and variability

    Two Group A Streptococcal Peptide Pheromones Act through Opposing Rgg Regulators to Control Biofilm Development

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    Streptococcus pyogenes (Group A Streptococcus, GAS) is an important human commensal that occasionally causes localized infections and less frequently causes severe invasive disease with high mortality rates. How GAS regulates expression of factors used to colonize the host and avoid immune responses remains poorly understood. Intercellular communication is an important means by which bacteria coordinate gene expression to defend against host assaults and competing bacteria, yet no conserved cell-to-cell signaling system has been elucidated in GAS. Encoded within the GAS genome are four rgg-like genes, two of which (rgg2 and rgg3) have no previously described function. We tested the hypothesis that rgg2 or rgg3 rely on extracellular peptides to control target-gene regulation. We found that Rgg2 and Rgg3 together tightly regulate two linked genes encoding new peptide pheromones. Rgg2 activates transcription of and is required for full induction of the pheromone genes, while Rgg3 plays an antagonistic role and represses pheromone expression. The active pheromone signals, termed SHP2 and SHP3, are short and hydrophobic (DI[I/L]IIVGG), and, though highly similar in sequence, their ability to disrupt Rgg3-DNA complexes were observed to be different, indicating that specificity and differential activation of promoters are characteristics of the Rgg2/3 regulatory circuit. SHP-pheromone signaling requires an intact oligopeptide permease (opp) and a metalloprotease (eep), supporting the model that pro-peptides are secreted, processed to the mature form, and subsequently imported to the cytoplasm to interact directly with the Rgg receptors. At least one consequence of pheromone stimulation of the Rgg2/3 pathway is increased biogenesis of biofilms, which counteracts negative regulation of biofilms by RopB (Rgg1). These data provide the first demonstration that Rgg-dependent quorum sensing functions in GAS and substantiate the role that Rggs play as peptide receptors across the Firmicute phylum

    Sparse Glider Datasets: A Case Study for NoSQL Databases

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    Multi-sensor platforms like buoys and gliders produce one or more readings per sensor on varying, discrete time frequencies. The resulting datasets are a matricies with rows containing readings from sensors that reported at a moment in time and NULL for missing readings from sensors that did not. Traditional Relational Database Management Systems (RDBMS) are already well suited for the dense matricies in which NULL values are infrequent. The efficiency of these systems deteriorates though as data becomes more sparse. The University of South Florida College of Marine Science Ocean Technology Group (COT) operates four gliders. Each glider produces dynamic, different sparse datasets. Other data management solutions exist, but they are based on a RDBMS. COT has been investigating an alternative without using and RDBMS. Glider Database Alternative with Mongo (GDAM) is a data management system for gliders built on the MongoDB NoSQL database engine. It is live in production at COT. GDAM is a collection of scripts which parse, process and store real-time glider datasets. Data is parsed as soon as it is transmitted via satellite to our shore-based servers. The system has been tested during two Slocum G1 glider deployments in September and October of 2012. Archival datasets dating back to March of 2009 have also been uploaded into this system. Records are indexed by time, GPS, and depth with the ability to add more indexes as necessary. The paper outlines dataset problems identified using data from COT glider operations in 2012. These problems inform a discussion of design decisions and possible options considering both RDBMS and NoSQL systems. The paper concludes by discussing the current implementation of GDAM

    Koordinierung der Entwicklungszusammenarbeit wichtiger OECD-Geberlaender

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    UuStB Koeln=38*-900106341 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

    A National Glider Network for Sustained Observation of the Coastal Ocean

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    A national glider network is essential to provide baseline ocean observations to connect the coastal and global ocean, and to address such issues as natural climate variability, ecosystem health, and water quality. The development of gliders is briefly reviewed. Requirements for a national network are presented, and the capabilities of gliders are shown to be suited for the task. The needs of a data management system tuned to gliders are outlined. A workshop to outline a strategy towards creating this network was held in August 2012, with a planning document to follow
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