bluuebunny/crossref_metadata_2025_split huggingface dataset:
Standard of Conduct or Standard of Review? Examination of an African Business Judgment Rule under South Africa's Companies Act 71 of 2008
Authors: Mupangavanhu Brighton M 
Published: January 2019

AbstractThis article highlights that section 76(4)(a) of South Africa's Companies Act, which reflects the business judgment rule (BJR) concept, is a standard of review, providing a means of determining whether a director has met his or her undertakings under section 76(3). The article suggests that section 76 should be titled “Standards of conduct and review” instead of referring only to standards of conduct. It draws a clear distinction between standards of conduct (including the personal financial interests disclosure requirements) on one hand, and a standard of review on the other. After tracing the traditional international requirements of BJR, the article analyses the decision-making requirements under section 76(4)(a). It concludes that, while section 76(4)(a) compares favourably with US and Australian laws, the omission of a good faith requirement is unfortunate since that is a critical component of decision-making. The article proposes that good faith and proper purpose under section 76(3)(a) should form part of the section 76(4)(a) requirements.
Variation in vegetation cover and seedling performance of tree species in a forest-savanna ecotone
Authors: Issifu Hamza , Ametsitsi George K. D. , de Vries Lana J. , Djagbletey Gloria Djaney , Adu-Bredu Stephen , Vergeer Philippine , van Langevelde Frank , Veenendaal Elmar 
Published: January 2019

AbstractDifferential tree seedling recruitment across forest-savanna ecotones is poorly understood, but hypothesized to be influenced by vegetation cover and associated factors. In a 3-y-long field transplant experiment in the forest-savanna ecotone of Ghana, we assessed performance and root allocation of 864 seedlings for two forest (Khaya ivorensis and Terminalia superba) and two savanna (Khaya senegalensis and Terminalia macroptera) species in savanna woodland, closed-woodland and forest. Herbaceous vegetation biomass was significantly higher in savanna woodland (1.0 ± 0.4 kg m−2 vs 0.2 ± 0.1 kg m−2 in forest) and hence expected fire intensities, while some soil properties were improved in forest. Regardless, seedling survival declined significantly in the first-year dry-season for all species with huge declines for the forest species (50% vs 6% for Khaya and 16% vs 2% for Terminalia) by year 2. After 3 y, only savanna species survived in savanna woodland. However, best performance for savanna Khaya was in forest, but in savanna woodland for savanna Terminalia which also had the highest biomass fraction (0.8 ± 0.1 g g−1 vs 0.6 ± 0.1 g g−1 and 0.4 ± 0.1 g g−1) and starch concentration (27% ± 10% vs 15% ± 7% and 10% ± 4%) in roots relative to savanna and forest Khaya respectively. Our results demonstrate that tree cover variation has species-specific effects on tree seedling recruitment which is related to root storage functions.
Hybrid ASP-based Approach to Pattern Mining
Authors: PARAMONOV SERGEY , STEPANOVA DARIA , MIETTINEN PAULI 
Published: January 2019

AbstractDetecting small sets of relevant patterns from a given data set is a central challenge in data mining. The relevance of a pattern is based on user-provided criteria; typically, all patterns that satisfy certain criteria are considered relevant. Rule-based languages like answer set programming (ASP) seem well suited for specifying such criteria in a form of constraints. Although progress has been made, on the one hand, on solving individual mining problems and, on the other hand, developing generic mining systems, the existing methods focus either on scalability or on generality. In this paper, we make steps toward combining local (frequency, size, and cost) and global (various condensed representations like maximal, closed, and skyline) constraints in a generic and efficient way. We present a hybrid approach for itemset, sequence, and graph mining which exploits dedicated highly optimized mining systems to detect frequent patterns and then filters the results using declarative ASP. To further demonstrate the generic nature of our hybrid framework, we apply it to a problem of approximately tiling a database. Experiments on real-world data sets show the effectiveness of the proposed method and computational gains for itemset, sequence, and graph mining, as well as approximate tiling.Under consideration in Theory and Practice of Logic Programming.
Semantic DMN: Formalizing and Reasoning About Decisions in the Presence of Background Knowledge
Authors: CALVANESE DIEGO , MONTALI MARCO , DUMAS MARLON , MAGGI FABRIZIO M. 
Published: January 2019

AbstractThe Decision Model and Notation (DMN) is a recent Object Management Group standard for the elicitation and representation of decision models and for managing their interconnection with business processes. DMN builds on the notion of decision tables and their combination into more complex decision requirements graphs (DRGs), which bridge between business process models and decision logic models. DRGs may rely on additional, external business knowledge models, whose functioning is not part of the standard. In this work, we consider one of the most important types of business knowledge, namely, background knowledge that conceptually accounts for the structural aspects of the domain of interest, and propose decision knowledge bases (DKBs), which semantically combine DRGs modeled in DMN, and domain knowledge captured by means of first-order logic with datatypes. We provide a logic-based semantics for such an integration, and formalize different DMN reasoning tasks for DKBs. We then consider background knowledge formulated as a description logic (DL) ontology with datatypes, and show how the main verification tasks for DMN in this enriched setting can be formalized as standard DL reasoning services and actually carried out in ExpTime. We discuss the effectiveness of our framework on a case study in maritime security.
A morphological revision of Keraterpeton, the earliest horned nectridean from the Pennsylvanian of England and Ireland
Authors: MILNER Angela C. 
Published: January 2019

ABSTRACTThe aquatic diplocaulid nectridean Keraterpeton galvani is the commonest taxon represented in the Jarrow Coal assemblage from Kilkenny, Ireland. The Jarrow locality has yielded the earliest known Carboniferous coal-swamp fauna in the fossil record and is, therefore, of importance in understanding the history and diversity of the diplocaulid clade. The morphology of Keraterpeton is described in detail with emphasis on newly observed anatomical features. A reconstruction of the palate includes the presence of interpterygoid vacuities and new morphological details of the pterygoid, parasphenoid and basicranial region. The hyoid apparatus comprising an ossified basibranchial element has not been reported previously in nectrideans. The structure of the scapulocoracoid and primitive nature of the humerus is described and the presence of a five-digit manus confirmed. Previously unrecognised accessory dermal ossifications are present in the pectoral girdle. Keraterpeton longtoni from the Bolsovian in Staffordshire, England, is also described and newly figured. The primitive condition in diplocaulids is defined on the basis of the earliest occurrence at Jarrow and discussed in relation to functional morphology and mode of life. The evolution of the diplocaulid clade is assessed in relation to the revised diagnoses that define the primitive condition in Keraterpeton.
Off-Target Movement of Diglycolamine Dicamba to Non-dicamba Soybean Using Practices to Minimize Primary Drift
Authors: Jones Gordon T. , Norsworthy Jason K. , Barber Tom 
Published: January 2019

AbstractSoybean with resistance to dicamba (DR soybean) and glyphosate and cotton with resistance to glyphosate, glufosinate, and dicamba were recently commercialized in the United States and have been readily adopted. To evaluate results of over-the-top application of dicamba in DR crops, field studies were designed to examine off-target movement using proposed sprayer setup recommendations. Association analysis and nonlinear regression techniques were used to examine the effects of 26 field-scale drift trials conducted in 2014 and 2015 during soybean reproductive development (R1 through R6). The greatest predictors (injury, height reduction) of soybean yield reduction generally occurred and had steeper relationships after drift events at the R1 growth stage than at later stages. Using non-DR soybean as an indicator, dicamba was documented to move as much as 152 m from the application area (distance to 5% injury). Instances of height reduction (5%) differed among growth stages, with the greatest distance occurring at R1 (83.4 m). Soybean yield reduction was erratic, with the greatest distance to 5% loss in yield occurring at 42.8 m after an R1 drift event. Overall, the data suggest flowering-stage soybean is more sensitive than later reproductive soybean to injury, height reductions, and yield loss. Average and maximum wind speeds did not account for the injury documented from dicamba, and it is hypothesized that other meteorological variables also play a notable role in dicamba off-target movement as well as growing conditions following exposure. With concerns surrounding off-target movement of dicamba, proper stewardship of this new technology will be key to its longevity.
Late Miocene Intensified Tectonic Uplift and Climatic Aridification on the Northeastern Tibetan Plateau: Evidence From Clay Mineralogical and Geochemical Records in the Xining Basin
Authors: Yang Rongsheng , Yang Yibo , Fang Xiaomin , Ruan Xiaobai , Galy Albert , Ye Chengcheng , Meng Qingquan , Han Wenxia 
Published: January 2019

AbstractThe uplift of the Tibetan Plateau (TP) during the late Cenozoic is thought to be one of crucial factors controlling Asian climate. However, the complex interaction between tectonics and climate change is still unclear. Here we present the first record of clay mineralogy and elemental geochemistry covering ~12.7–4.8 Ma in a fluvial‐lacustrine sequence in the Xining Basin. Geochemical provenance proxies (Th/Sc, Zr/Sc, and Cr/Zr) in the <2‐μm fraction show a significant provenance change at ~8.8 Ma. Silicate‐based weathering indexes (CIA, CIW, and PIA) displayed coeval changes with provenance but discrepant changes with regional climate. Since the clay mineralogy exhibits significant change at ~7.8 Ma uncorrelated with modifications in provenance, it can be employed to reveal regional climate change. The rise in illite and associated decrease in the sum of smectite and illite/smectite mixed layers reflect gradual and slow aridification since ~12.7 Ma with intensified drying since ~7.8 Ma until approaching the modern climate status. Our results, together with other regional climatic and tectonic records, clearly illustrate that accelerated uplift of the northeastern TP since ~8–9 Ma has mainly modulated the regional erosion, weathering, transportation, and sedimentation and amplified the global cooling and drying trend toward the regional climate of modern conditions. Our study suggests that in the tectonically active northeastern TP, a comprehensive mineralogical and geochemical investigation of the fine‐grained fraction of the basin sediments could retrieve the interactions between tectonics and climate behind the complex change in exhumed lithology and sedimentary routing systems.
Determination of the Refractive Contribution to GPS Phase “Scintillation”
Authors: McCaffrey A. M. , Jayachandran P. T. 
Published: January 2019

AbstractAs L‐band radio waves travel through the ionosphere, such as those transmitted by the Global Positioning System (GPS) satellites, changes in the electron density along the ray path may induce refractive and/or diffractive variations in the signal's phase; where refractive variations are deterministic and diffractive variations are stochastic. Typically, the refractive component of these variations is thought to be slow varying, associated with frequencies less than 0.1 Hz. Therefore, if the refractive contribution is assumed to be associated with frequencies less than 0.1 Hz, the frequencies greater than 0.1 Hz are then assumed and treated as diffractive. These variations are usually referred to as scintillation. In scintillation studies the deterministic refractive variations are very often ignored. We propose that rapid changes in the electron density, and therefore changes in the refractive index along the ray path of the GPS signal, can induce dominantly refractive variations at frequencies greater than 0.1 Hz. The increased drift speeds observed in the high‐latitude region create conditions suitable for these high‐frequency refractive variations; the GPS ray path will sweep through large‐scale irregularities at higher speeds, resulting in high‐frequency refractive variations. Using recent advances in GPS, most importantly an improved signal tracking technique, we present examples of rapid refractive variations in the GPS signal's phase. These high‐frequency variations are shown to be refractive using a combination of techniques, one adapted from a previous technique used for the low‐frequency refractive contributions and a new technique only possible with advances in GPS tracking.
Linking Structural and Transport Properties in Three‐Dimensional Fracture Networks
Authors: Hyman J. D. , Dentz M. , Hagberg A. , Kang P. K. 
Published: January 2019

AbstractWe investigate large‐scale particle motion and solute breakthrough in sparse three‐dimensional discrete fracture networks characterized by power law distributed fracture lengths. The three networks we consider have the same fracture intensity values but exhibit different percolation densities, geometric properties, and topological structures. We considered two different average transport models to predict solute breakthrough, a streamtube model and a Bernoulli continuous time random walk model, both of which provide insights into the flow fields within the networks. The streamtube model provides acceptable predictions at short distances in two of the networks but fails in all cases to predict breakthrough times at the outlet plane, which indicates that particle motion in such fracture networks cannot be characterized by a constant velocity between the inlet and control plane at which the breakthrough curve is detected. Rather, the structure of the network requires that frequent velocity transitions be made as particles move through the system. Despite the relatively broad distribution of fracture radii and relatively small number of independent velocity transitions, the continuous time random walk approach conditioned on the initial velocity distribution provides reasonable predictions for the breakthrough curves at different distances from the inlet. The application of these averaged transport models provides a richer understanding of the link from the fracture network structure to flow and transport properties.
P Wave Teleseismic Traveltime Tomography of the North American Midcontinent
Authors: Bollmann Trevor A. , van der Lee Suzan , Frederiksen Andrew W. , Wolin Emily , Revenaugh Justin , Wiens Douglas A. , Darbyshire Fiona A. , Stein Seth , Wysession Michael E. , Jurdy Donna 
Published: January 2019

AbstractThe remains of the 1.1‐Ga Midcontinent Rift (MCR) lie in the middle of the tectonically stable portion of North America. Previous and ongoing studies have imaged strong heterogeneity associated with the MCR in the crust but have not imaged such within the mantle. It is unclear whether this is due to the absence of rift‐related mantle structures or these studies had insufficient resolution to image them. To address this issue, we measured 46,374 teleseismic P wave delay times from seismograms recorded by the USArray Transportable Array, Superior Province Rifting EarthScope Experiment, and surrounding permanent stations. We included these and 54,866 delay times from prior studies in our tomographic inversion. We find that high‐velocity anomalies are widespread in our study area, but there are also prominent low‐velocity anomalies. Two of these are coincident with high‐Bouguer gravity anomalies associated with the MCR in Iowa and the Minnesota/Wisconsin border at 50‐ to 150‐km depth. Extensive resolution testing shows that these anomalies could be the result of downward vertical smearing of relatively low velocities from rift‐related material that “underplated" the crust, although we cannot exclude that the subcrustal mantle lithosphere beneath the MCR is anomalously enriched, hydrated, or warm. Other anomalies occur at syntaxes of the Penokean Orogen. One with the Superior Province and Marshfield Terrane in southern Minnesota and another with the Yavapai and Mazatzal Terranes, both at 100‐ to 250‐km depth. In the midmantle, we image two linear high‐velocity anomalies, interpreted as subducted fragments of the Farallon and Kula plates.
PhaseLink: A Deep Learning Approach to Seismic Phase Association
Authors: Ross Zachary E. , Yue Yisong , Meier Men‐Andrin , Hauksson Egill , Heaton Thomas H. 
Published: January 2019

AbstractSeismic phase association is a fundamental task in seismology that pertains to linking together phase detections on different sensors that originate from a common earthquake. It is widely employed to detect earthquakes on permanent and temporary seismic networks and underlies most seismicity catalogs produced around the world. This task can be challenging because the number of sources is unknown, events frequently overlap in time, or can occur simultaneously in different parts of a network. We present PhaseLink, a framework based on recent advances in deep learning for grid‐free earthquake phase association. Our approach learns to link phases together that share a common origin and is trained entirely on millions of synthetic sequences of P and S wave arrival times generated using a 1‐D velocity model. Our approach is simple to implement for any tectonic regime, suitable for real‐time processing, and can naturally incorporate errors in arrival time picks. Rather than tuning a set of ad hoc hyperparameters to improve performance, PhaseLink can be improved by simply adding examples of problematic cases to the training data set. We demonstrate the state‐of‐the‐art performance of PhaseLink on a challenging sequence from southern California and synthesized sequences from Japan designed to test the point at which the method fails. For the examined data sets, PhaseLink can precisely associate phases to events that occur only ∼12 s apart in origin time. This approach is expected to improve the resolution of seismicity catalogs, add stability to real‐time seismic monitoring, and streamline automated processing of large seismic data sets.
Short‐Term Variations in the Surface Upwelling off Northeastern Taiwan Observed via Satellite Data
Authors: Yin Wenbin , Huang Daji 
Published: January 2019

AbstractShort‐term biweekly variations in the surface upwelling off northeastern Taiwan are well documented. However, due to limitations in the spatiotemporal resolution and coverage of the observed data, the lifecycle and associated dynamics are poorly understood. In this study, a gradient‐based edge detection algorithm is proposed to detect the surface upwelling. The sea surface temperature data of geostationary satellite Himawari‐8 were used to explore a complete short‐term process as a case study. The evolution was analyzed in terms of an upwelling index measured via the temperature difference between upwelled and surrounding water and the area and shape of the surface upwelling. The process lasted approximately 17 days as the upwelling moved northeastward under the advection of the Kuroshio Current and included two stages: intensification and decay. The last 8 years (2010–2017) of multisatellite combined sea surface temperature data were examined to verify the results obtained in the case study. A statistical analysis shows that most of the short‐term processes occur in the summer with an average lifecycle of approximately 15 ± 5 days. The trajectories of the upwelling center can be grouped into three types: quasi‐stationary near the shelf break, moving northward across the shelf break, and moving northeastward along the shelf break. A preliminary discussion suggests that the observed variations may be caused by the collective effects of multiple dynamical mechanisms, such as fluctuations in the Kuroshio Current, surface wind curl, and typhoons. This study furthers our knowledge of the surface upwelling off northeastern Taiwan and provides constraints for numerical simulations.
Timescale for Detecting the Climate Response to Stratospheric Aerosol Geoengineering
Authors: MacMartin Douglas G. , Wang Wenli , Kravitz Ben , Tilmes Simone , Richter Jadwiga H. , Mills Michael J. 
Published: January 2019

AbstractStratospheric aerosol geoengineering could be used to maintain global mean temperature despite increased atmospheric greenhouse gas (GHG) concentrations, for example, to meet a 1.5 or 2 °C target. While this might reduce many climate change impacts, the resulting climate would not be the same as one with the same global mean temperature due to lower GHG concentrations. The primary question we consider is how long it would take to detect these differences in a hypothetical deployment. We use a 20‐member ensemble of stratospheric sulfate aerosol geoengineering simulations in which SO2 is injected at four different latitudes to maintain not just the global mean temperature, but also the interhemispheric and equator‐to‐pole gradients. This multiple‐latitude strategy better matches the climate changes from increased GHG, while the ensemble allows us both to estimate residual differences even when they are small compared to natural variability and to estimate the statistics of variability. We first construct a linear emulator to predict the model responses for different scenarios. Under an RCP4.5 scenario in which geoengineering maintains a 1.5 °C target (providing end‐of‐century cooling of 1.7 °C), the projected changes in temperature, precipitation, and precipitation minus evaporation (P − E) at a grid‐scale are typically small enough that in many regions the signal‐to‐noise ratio is still less than one at the end of this century; for example, for P − E, only 30% of the land area reaches a signal‐to‐noise ratio of one. These results provide some context for the projected magnitude of climate changes associated with a limited deployment of stratospheric aerosol cooling.