bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensitivity of emergent sociohydrologic dynamics to internal system properties and external sociopolitical factors: Implications for water management
Authors: Elshafei Y. , Tonts M. , Sivapalan M. , Hipsey M. R. 
Published: May 2016

AbstractIt is increasingly acknowledged that effective management of water resources requires a holistic understanding of the coevolving dynamics inherent in the coupled human‐hydrology system. One of the fundamental information gaps concerns the sensitivity of coupled system feedbacks to various endogenous system properties and exogenous societal contexts. This paper takes a previously calibrated sociohydrology model and applies an idealized implementation, in order to: (i) explore the sensitivity of emergent dynamics resulting from bidirectional feedbacks to assumptions regarding (a) internal system properties that control the internal dynamics of the coupled system and (b) the external sociopolitical context; and (ii) interpret the results within the context of water resource management decision making. The analysis investigates feedback behavior in three ways, (a) via a global sensitivity analysis on key parameters and assessment of relevant model outputs, (b) through a comparative analysis based on hypothetical placement of the catchment along various points on the international sociopolitical gradient, and (c) by assessing the effects of various direct management intervention scenarios. Results indicate the presence of optimum windows that might offer the greatest positive impact per unit of management effort. Results further advocate management tools that encourage an adaptive learning, community‐based approach with respect to water management, which are found to enhance centralized policy measures. This paper demonstrates that it is possible to use a place‐based sociohydrology model to make abstractions as to the dynamics of bidirectional feedback behavior, and provide insights as to the efficacy of water management tools under different circumstances.
Methane emission through ebullition from an estuarine mudflat: 1. A conceptual model to explain tidal forcing based on effective stress changes
Authors: Chen Xi , Slater Lee 
Published: May 2016

AbstractEbullition is an important pathway for transport of methane (CH4) to the atmosphere in wetlands. Water level changes have been suggested to trigger ebullition, especially in tidally flooded areas, although the controlling mechanisms remain uncertain. Bubble transport in submerged sediment represents a multiphase, dynamic interaction between gaseous and solid phases under the modulation of a liquid phase. An unvegetated sediment monolith was retrieved from an estuarine mudflat area at a tidal marsh site and maintained in a saturated state. Laboratory measurements on the mud monolith confirmed that not only ebbing tides, but also flooding tides could trigger ebullition releases of gas bubbles. We develop a Changing Stress for Simulating Ebullition (CSSE) model to describe mechanisms controlling bubble expansion in response to water level changes to unify these observations. Decreases in water level are assumed to lower the effective stress surrounding isolated trapped gas bubbles, driving upward transport via bubble expansion and deformation, with associated fracturing of overlying sediments. Increases in relative permittivity suggest that additional water invades macropores, with associated pore expansion, during the initial stage of increases in water level. We propose that subsequent matrix expansion under lowered effective stress on rising tides also leads to fracture propagation and bubble release. Our findings demonstrate the importance of effective stress changes in triggering ebullition from mudflat areas in tidal wetlands, modulated by the mechanical properties of shallow soft sediments.
Flash flooding in small urban watersheds: Storm event hydrologic response
Authors: Yang Long , Smith James A. , Baeck Mary Lynn , Zhang Yan 
Published: May 2016

AbstractWe analyze flash flooding in small urban watersheds, with special focus on the roles of rainfall variability, antecedent soil moisture, and urban storm water management infrastructure in storm event hydrologic response. Our results are based on empirical analyses of high‐resolution rainfall and discharge observations over Harry's Brook watershed in Princeton, New Jersey, during 2005–2006, as well as numerical experiments with the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model. We focus on two subwatersheds of Harry's Brook, a 1.1 km2 subwatershed which was developed prior to modern storm water management regulations, and a 0.5 km2 subwatershed with an extensive network of storm water detention ponds. The watershed developed prior to modern storm water regulations is an “end‐member” in urban flood response, exhibiting a frequency of flood peaks (with unit discharge exceeding 1 m3 s−1 km−2) that is comparable to the “flashiest” watersheds in the conterminous U.S. Observational analyses show that variability in storm event water balance is strongly linked to peak rain rates at time intervals of less than 30 min and only weakly linked to antecedent soil moisture conditions. Peak discharge for both the 1.1 and 0.5 km2 subwatersheds are strongly correlated with rainfall rate averaged over 1–30 min. Hydrologic modeling analyses indicate that the sensitivity of storm event hydrologic response to spatial rainfall variability decreases with storm intensity. Temporal rainfall variability is relatively more important than spatial rainfall variability in representing urban flood response, especially for extreme storm events.
Variability in isotopic composition of base flow in two headwater streams of the southern Appalachians
Authors: Singh Nitin K. , Emanuel Ryan E. , McGlynn Brian L. 
Published: May 2016

AbstractWe investigated the influence of hillslope scale topographic characteristics and the relative position of hillslopes along streams (i.e., internal catchment structure) on the isotopic composition of base flow in first‐order, forested headwater streams at Coweeta Hydrologic Laboratory. The study focused on two adjacent forested catchments with different topographic characteristics. We used stable isotopes (18O and 2H) of water together with stream gauging and geospatial analysis to evaluate relationships between internal catchment structure and the spatiotemporal variability of base flow δ18O. Base flow δ18O was variable in space and time along streams, and the temporal variability of base flow δ18O declined with increasing drainage area. Base flow became enriched in 18O moving along streams from channel heads to catchment outlets but the frequency of enrichment varied between catchments. The spatiotemporal variability in base flow δ18O was high adjacent to large hillslopes with short flow paths, and it was positively correlated with the relative arrangement of hillslopes within the catchment. These results point to influence of unique arrangement of hillslopes on the patterns of downstream enrichment. Spatial variability in base flow δ18O within the streams was relatively low during dry and wet conditions, but it was higher during the transition period between dry and wet conditions. These results suggest that the strength of topographic control on the isotopic composition of base flow can vary with catchment wetness. This study highlights that topographic control on base flow generation and isotopic composition is important even at fine spatial scales.
Geophysical controls of chemical disequilibria in Europa
Authors: Vance S. D. , Hand K. P. , Pappalardo R. T. 
Published: May 2016

AbstractThe ocean in Jupiter's moon Europa may have redox balance similar to Earth's. On Earth, low‐temperature hydration of crustal olivine produces substantial hydrogen, comparable to any potential flux from volcanic activity. Here we compare hydrogen and oxygen production rates of the Earth system with fluxes to Europa's ocean. Even without volcanic hydrothermal activity, water‐rock alteration in Europa causes hydrogen fluxes 10 times smaller than Earth's. Europa's ocean may have become reducing for a brief epoch, for example, after a thermal‐orbital resonance ∼2 Gyr after accretion. Estimated oxidant flux to Europa's ocean is comparable to estimated hydrogen fluxes. Europa's ice delivers oxidants to its ocean at the upper end of these estimates if its ice is geologically active, as evidence of geologic activity and subduction implies.
Solar cycle variation of the statistical distribution of the solar wind ε parameter and its constituent variables
Authors: Tindale E. , Chapman S. C. 
Published: May 2016

AbstractWe use 20 years of Wind solar wind observations to investigate the solar cycle variation of the solar wind driving of the magnetosphere. For the first time, we use generalized quantile‐quantile plots to compare the statistical distribution of four commonly used solar wind coupling parameters, Poynting flux, B2, the ε parameter, and vB, between the maxima and minima of solar cycles 23 and 24. We find the distribution is multicomponent and has the same functional form at all solar cycle phases; the change in distribution is captured by a simple transformation of variables for each component. The ε parameter is less sensitive than its constituent variables to changes in the distribution of extreme values between successive solar maxima. The quiet minimum of cycle 23 manifests only in lower extreme values, while cycle 24 was less active across the full distribution range.
Systematic correlations of the earthquake frequency‐magnitude distribution with the deformation and mechanical regimes in the Taiwan orogen
Authors: Chen Yen‐Ling , Hung Shu‐Huei , Jiang Juen‐Shi , Chiao Ling‐Yun 
Published: May 2016

AbstractWe investigate the correlation of the earthquake frequency‐magnitude distribution with the style of faulting and stress in Taiwan. The b values estimated for three types of focal mechanisms show significant differences with the lowest for thrust, intermediate for strike slip, and highest value for normal events, consistent with those found in global and other regional seismicity. Lateral distribution of the b values shows a good correlation with the predominant faulting mechanism, crustal deformation, and stress patterns. The two N‐S striking thrust zones in western and eastern Taiwan under the larger E‐W shortening and differential stress yield the lower b values than those in the in‐between mountain ranges subject to the smaller extensional stress and dominated by strike slip and normal faults. The termination of the monotonically decreasing b value with depth at ~15–20 km corroborates its inverse relationship with stress and the existence of the brittle‐plastic transition in the weak middle crust beneath the Taiwan orogen.
Electron dropout echoes induced by interplanetary shock: Van Allen Probes observations
Authors: Hao Y. X. , Zong Q.‐G. , Zhou X.‐Z. , Fu S. Y. , Rankin R. , Yuan C.‐J. , Lui A. T. Y. , Spence H. E. , Blake J. B. , Baker D. N. , Reeves G. D. 
Published: May 2016

AbstractOn 23 November 2012, a sudden dropout of the relativistic electron flux was observed after an interplanetary shock arrival. The dropout peaks at ∼1 MeV and more than 80% of the electrons disappeared from the drift shell. Van Allen twin Probes observed a sharp electron flux dropout with clear energy dispersion signals. The repeating flux dropout and recovery signatures, or “dropout echoes”, constitute a new phenomenon referred to as a “drifting electron dropout” with a limited initial spatial range. The azimuthal range of the dropout is estimated to be on the duskside, from ∼1300 to 0100 LT. We conclude that the shock‐induced electron dropout is not caused by the magnetopause shadowing. The dropout and consequent echoes suggest that the radial migration of relativistic electrons is induced by the strong dusk‐dawn asymmetric interplanetary shock compression on the magnetosphere.
Plankton patchiness investigated using simultaneous nitrate and chlorophyll observations
Authors: van Gennip Simon , Martin Adrian P. , Srokosz Meric A. , Allen John T. , Pidcock Rosalind , Painter Stuart C. , Stinchcombe Mark C. 
Published: May 2016

AbstractThe complex patterns observed in marine phytoplankton distributions arise from the interplay of biological and physical processes, but the nature of the balance remains uncertain centuries after the first observations. Previous observations have shown a consistent trend of decreasing variability with decreasing length scale. Influenced by similar scaling found for the properties of the water that the phytoplankton inhabit, “universal” theories have been proposed that simultaneously explain the variability seen from meters to hundreds of kilometers. However, data on the distribution of phytoplankton alone have proved insufficient to differentiate between the many causal mechanisms that have been suggested. Here we present novel observations from a cruise in the North Atlantic in which fluorescence (proxy for phytoplankton), nitrate, and temperature were measured simultaneously at scales from 10 m to 100 km for the first time in the open ocean. These show a change in spectra between the small scale (10–100 m) and the mesoscale (10–100 km) which is different for the three tracers. We discuss these observations in relation to the current theories for phytoplankton patchiness.
Mapping Disease Patterns
Authors: Barford Anna , Dorling Daniel 
Published: May 2016

AbstractCartograms make a distinctive contribution to disease mapping. By resizing areas of a map, not by land area but instead by another variable of interest, maps become humanized. In a cartogram health, population, morbidity, mortality, prevention, or control measures take the central role of determining the dimensions of the map. Map reading changes in nature; what is striking to the map reader when area is distorted by disease prevalence is not the larger land area, or a bolder color, but those expanded areas where the most is happening with regards to the map topic. This article showcases several instances of disease mapping with cartograms. We focus on the development of cartograms and two cholera epidemics, the one in London in 1848 and the other in Haiti, which began in 2010. Other forms of mapping are introduced to show the value of using several map forms in conjunction with one another.
Rasch Models for Measuring Change
Authors: Meiser Thorsten , Steinwascher Merle , Plieninger Hansjörg 
Published: May 2016

AbstractThis article presents Rasch models for the analysis of longitudinal discrete data and testing specific hypotheses about change. It is shown that Rasch models can be represented in terms of log‐linear models and hierarchical linear or factor models with a logit link function, which allows the specification of Rasch models using general software packages. The use of Rasch models for longitudinal data is illustrated with an empirical example. The final section discusses model extensions for the analysis of polytomous items, multidimensional latent constructs, and items with varying discrimination parameters.
Computer‐Adaptive Testing
Authors: Luecht Richard M. 
Published: May 2016

AbstractThis article presents an overview of computer‐adaptive testing (CAT). The basic CAT algorithm is introduced, followed by a discussion of item response theory (IRT) test information functions and their role in adaptive testing. Issues such as test efficiency and security risks under CAT are also discussed. This article concludes with a description of four promising CAT variants, including CAT shadow tests, a‐stratified CAT, testlet‐based CAT, and computer‐adaptive multistage testing.
Model Identifiability
Authors: Huang Guan‐Hua 
Published: May 2016

AbstractA model is identifiable if there is a one‐to‐one correspondence between the probability distribution of the data and the values of model parameters. When applying a nonidentifiable model, different people may draw different conclusions from the same model of the observed data. Before one can meaningfully discuss the estimation of a model, model identifiability must be verified.
Water Quality Modeling
Authors: Whitehead Paul G. 
Published: May 2016

AbstractIn addition to being major sources of water, river systems are used as the principal disposal pathways for industrial, agricultural, and domestic effluent. As demand for water increases and water quality deteriorates, there is a requirement for effective decision‐making techniques that can be applied to solve water quality management problems. Over the past century, increasing effort has been devoted to the development of suitable techniques, largely by engineers, system analysts, and scientists. Since 1912, the Royal Commission on Environmental Pollution in the UK proposed a simple 1–8 ratio for effluent discharge to river flow in an attempt to clean up UK rivers. In the United States, major developments by Streeter and Phelps led to the dissolved oxygen (DO) and biochemical oxygen demand (BOD) equations that enable steady‐state and dynamic modeling of oxygen balances in rivers. Major studies in the area of water quality modeling were undertaken in the United States (e.g., Great Lakes, Delaware Study), the United Kingdom (e.g., Trent Study and Bedford Case Study), and Australia (Peel–Harvey Inlet), and these all evolved new techniques to address major water quality problems. More recently, the INCA (Integrated Nitrogen in Catchments) family of models has been developed to link hydrology, water quality, and ecology across catchment systems.
Gerüstdiversitätsbasierte Synthese und ihre Anwendung bei der Sonden‐ und Wirkstoffsuche
Authors: Garcia‐Castro Miguel , Zimmermann Stefan , Sankar Muthukumar G. , Kumar Kamal 
Published: May 2016

AbstractDie Gerüstdiversität ist ein entscheidendes Merkmal von Verbindungskollektionen, das einen großen Einfluss auf deren Erfolg beim biologischen Screening hat. Die Synthese hochkomplexer und verschiedenartiger Gerüste, die beispielsweise auf Naturstoffen aufbauen könnte, ist eine mühsame Aufgabe, die in einer Reihe von Aspekten der organischen Synthese und Strukturanalyse Fachkompetenz erfordert. Diese Herausforderung wurde mithilfe etlicher Synthesemodelle angegangen, die Naturstoffe als Quelle der Gerüstdiversität einsetzen, passend gestaltete gängige Intermediate in verschiedene Molekülgerüste umwandeln oder zu hochpräzisen Synthesewegen für etliche unterschiedliche und komplexe Gerüste führen. In diesem Kurzaufsatz stellen wir neue Ansätze zur Synthese verschiedenartiger und komplexer Gerüste sowie die Anwendung der resultierenden Verbindungskollektionen bei der Suche nach Wirkstoffen und Sonden vor.
Total Synthesis of (+)‐Minfiensine: Construction of the Tetracyclic Core Structure by an Asymmetric Cascade Cyclization
Authors: Zhang Ze‐Xin , Chen Si‐Cong , Jiao Lei 
Published: May 2016

AbstractA new method for one‐step construction of the tetracyclic core structure of the indole alkaloid (+)‐minfiensine was developed utilizing a palladium‐catalyzed asymmetric indole dearomatization/iminium cyclization cascade. An efficient total synthesis of (+)‐minfiensine was realized using this strategy. The present method enables access to the common core structure of a series of monoterpene indole alkaloids, such as vincorine, echitamine, and aspidosphylline A.
Scaffold Diversity Synthesis and Its Application in Probe and Drug Discovery
Authors: Garcia‐Castro Miguel , Zimmermann Stefan , Sankar Muthukumar G. , Kumar Kamal 
Published: May 2016

AbstractScaffold diversity is a crucial feature of compound collections that has a huge impact on their success in biological screenings. The synthesis of highly complex and diverse scaffolds, which could be based on natural products, for example, is an arduous task that requires expertise in various aspects of organic synthesis and structural analysis. This challenge has been addressed by a number of synthesis designs, which employ natural products as a source of scaffold diversity, transform suitably designed common intermediates into various molecular frameworks, or entail highly concise synthetic routes to a number of distinct and complex scaffolds. In this Minireview, we highlight recent synthetic developments towards the construction of diverse and complex scaffolds and the application of the resulting compound collections in drug and probe discovery.
Resistant in‐stent restenosis in the drug eluting stent era
Authors: Theodoropoulos Kleanthis , Mennuni Marco G. , Dangas George D. , Meelu Omar A. , Bansilal Sameer , Baber Usman , Sartori Samantha , Kovacic Jason C. , Moreno Pedro R. , Sharma Samin K. , Mehran Roxana , Kini Annapoorna S. 
Published: May 2016

BackgroundIn the drug eluting stent (DES) era, repeat in‐stent restenosis (ISR) of the same coronary lesion, despite percutaneous coronary intervention (PCI), is a rare but challenging problem that has not been reported. We aim to describe what we propose as the occurrence of “resistant”‐ISR (R‐ISR) in the DES era, including angiographic patterns and outcomes.MethodsWe defined R‐ISR as the recurrence of an ISR episode after successful treatment of the same lesion. We identified 276 consecutive patients with 291 lesions who had R‐ISR between May 2003 and June 2012. Quantitative coronary angiography (QCA) was performed for the first and second ISR episodes. Outcomes at one year, including death, myocardial infarction (MI), and target lesion failure (TLF), were analyzed.ResultsPatients with R‐ISR had a high frequency of diabetes (62%), chronic kidney disease (39%), bifurcation lesions (51%), and moderate to severe calcified lesions (52%). The most common pattern of R‐ISR was focal (77%). R‐ISR lesions were treated with DES implantation (55%) or balloon‐only strategy (45%). The mortality rate and TLF at 2‐years were 9.3% and 51% respectively. The overall 2‐year TLF rate did not vary with the originally implanted stent, angiographic pattern (focal versus diffuse), or revascularization strategy.ConclusionsR‐ISR appears to consist predominantly of focal lesions and occurs in patients at high clinical and angiographic risk, conceivably owing to their unique diabetic and coronary calcification profile. Clinical outcomes are suboptimal irrespective of angiographic pattern or treatment strategy, indicating the recalcitrant nature of the disease, and need for aggressive treatment of cardiovascular risk factors and novel interventional approaches. © 2016 Wiley Periodicals, Inc.