bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in anthropogenic nitrogen and phosphorus inputs to the St. Lawrence sub‐basin over 110 years and impacts on riverine export
Authors: Goyette Jean‐Olivier , Bennett Elena M. , Howarth Robert W. , Maranger Roxane 
Published: June 2016

AbstractHuman activities have increased the flow of nitrogen (N) and phosphorus (P) over much of the Earth, leading to increased agricultural production, but also the degradation of air, soil, and water quality. Here we quantify the sources of anthropogenic N and P inputs to 76 watersheds of the St. Lawrence Basin (SLB) throughout the 20th century using NANI/NAPI (net anthropogenic N/P input to watersheds), a mass balance modeling approach, and estimate the fraction of these inputs exported to adjacent rivers. Our results show that since 1901, NANI and NAPI increased 4.5‐fold and 3.8‐fold, respectively, with a peak in 1991 mainly due to high atmospheric N deposition and P fertilizer application. However, the relative increase over the course of the last century was much higher in certain watersheds, particularly those where there was greater urbanization. Ranges in NANI and NAPI vary greatly among watersheds (110 to 9351 kg N km−2 yr−1 and 0.16 to 1938 kg P km−2 yr−1, respectively in 2011) and are strongly related to riverine fluxes (R2 = 0.87 and 0.71 for N and P, respectively). Our results suggest that 22% of NANI (ranging from 11% to 68% across watersheds) and 17% of NAPI (ranging from 3% to 173%) are exported to rivers. Predominant sources of inputs vary spatially and through time largely due to changes in farming practices. By tracking the main sources of inputs to specific watersheds and through time, our work provides insights for N and P management. Reduction strategies will likely need to be watershed specific, although through time, our results clearly show the large‐scale impact of targeted legislation.
Variability in the sensitivity among model simulations of permafrost and carbon dynamics in the permafrost region between 1960 and 2009
Authors: McGuire A. David , Koven Charles , Lawrence David M. , Clein Joy S. , Xia Jiangyang , Beer Christian , Burke Eleanor , Chen Guangsheng , Chen Xiaodong , Delire Christine , Jafarov Elchin , MacDougall Andrew H. , Marchenko Sergey , Nicolsky Dmitry , Peng Shushi , Rinke Annette , Saito Kazuyuki , Zhang Wenxin , Alkama Ramdane , Bohn Theodore J. , Ciais Philippe , Decharme Bertrand , Ekici Altug , Gouttevin Isabelle , Hajima Tomohiro , Hayes Daniel J. , Ji Duoying , Krinner Gerhard , Lettenmaier Dennis P. , Luo Yiqi , Miller Paul A. , Moore John C. , Romanovsky Vladimir , Schädel Christina , Schaefer Kevin , Schuur Edward A.G. , Smith Benjamin , Sueyoshi Tetsuo , Zhuang Qianlai 
Published: June 2016

AbstractA significant portion of the large amount of carbon (C) currently stored in soils of the permafrost region in the Northern Hemisphere has the potential to be emitted as the greenhouse gases CO2 and CH4 under a warmer climate. In this study we evaluated the variability in the sensitivity of permafrost and C in recent decades among land surface model simulations over the permafrost region between 1960 and 2009. The 15 model simulations all predict a loss of near‐surface permafrost (within 3 m) area over the region, but there are large differences in the magnitude of the simulated rates of loss among the models (0.2 to 58.8 × 103 km2 yr−1). Sensitivity simulations indicated that changes in air temperature largely explained changes in permafrost area, although interactions among changes in other environmental variables also played a role. All of the models indicate that both vegetation and soil C storage together have increased by 156 to 954 Tg C yr−1 between 1960 and 2009 over the permafrost region even though model analyses indicate that warming alone would decrease soil C storage. Increases in gross primary production (GPP) largely explain the simulated increases in vegetation and soil C. The sensitivity of GPP to increases in atmospheric CO2 was the dominant cause of increases in GPP across the models, but comparison of simulated GPP trends across the 1982–2009 period with that of a global GPP data set indicates that all of the models overestimate the trend in GPP. Disturbance also appears to be an important factor affecting C storage, as models that consider disturbance had lower increases in C storage than models that did not consider disturbance. To improve the modeling of C in the permafrost region, there is the need for the modeling community to standardize structural representation of permafrost and carbon dynamics among models that are used to evaluate the permafrost C feedback and for the modeling and observational communities to jointly develop data sets and methodologies to more effectively benchmark models.
Asteroid bombardment and the core of Theia as possible sources for the Earth's late veneer component
Authors: Sleep Norman H. 
Published: June 2016

AbstractThe silicate Earth contains Pt‐group elements in roughly chondritic relative ratios, but with absolute concentrations <1% chondrite. This veneer implies addition of chondrite‐like material with 0.3–0.7% mass of the Earth's mantle or an equivalent planet‐wide thickness of 5–20 km. The veneer thickness, 200–300 m, within the lunar crust and mantle is much less. One hypothesis is that the terrestrial veneer arrived after the moon‐forming impact within a few large asteroids that happened to miss the smaller Moon. Alternatively, most of terrestrial veneer came from the core of the moon‐forming impactor, Theia. The Moon then likely contains iron from Theia's core. Mass balances lend plausibility. The lunar core mass is ∼1.6 × 1021kg and the excess FeO component in the lunar mantle is 1.3–3.5 × 1021kg as Fe, totaling 3–5 × 1021kg or a few percent of Theia's core. This mass is comparable to the excess Fe of 2.3–10 × 1021kg in the Earth's mantle inferred from the veneer component. Chemically in this hypothesis, Fe metal from Theia's core entered the Moon‐forming disk. H2O and Fe2O3in the disk oxidized part of the Fe, leaving the lunar mantle near a Fe‐FeO buffer. The remaining iron metal condensed, gathered Pt‐group elements eventually into the lunar core. The silicate Moon is strongly depleted in Pt‐group elements. In contrast, the Earth's mantle contained excess oxidants, H2O and Fe2O3, which quantitatively oxidized the admixed Fe from Theia's core, retaining Pt‐group elements. In this hypothesis, asteroid impacts were relatively benign with ∼1 terrestrial event that left only thermophile survivors.
The influences of solar wind pressure and interplanetary magnetic field on global magnetic field and outer radiation belt electrons
Authors: Yu J. , Li L.Y. , Cao J. B. , Reeves G. D. , Baker D. N. , Spence H. 
Published: June 2016

AbstractUsing the Van Allen Probe in situ measured magnetic field and electron data, we examine the solar wind dynamic pressure and interplanetary magnetic field (IMF) effects on global magnetic field and outer radiation belt relativistic electrons (≥1.8 MeV). The dynamic pressure enhancements (>2 nPa) cause the dayside magnetic field increase and the nightside magnetic field reduction, whereas the large southward IMFs (Bz‐IMF < −2nT) mainly lead to the decrease of the nightside magnetic field. In the dayside increased magnetic field region (magnetic local time (MLT) ~ 06:00–18:00, and L > 4), the pitch angles of relativistic electrons are mainly pancake distributions with a flux peak around 90° (corresponding anisotropic index A > 0.1), and the higher‐energy electrons have stronger pancake distributions (the larger A), suggesting that the compression‐induced betatron accelerations enhance the dayside pancake distributions. However, in the nighttime decreased magnetic field region (MLT ~ 18:00–06:00, and L ≥ 5), the pitch angles of relativistic electrons become butterfly distributions with two flux peaks around 45° and 135° (A < 0). The spatial range of the nighttime butterfly distributions is almost independent of the relativistic electron energy, but it depends on the magnetic field day‐night asymmetry and the interplanetary conditions. The dynamic pressure enhancements can make the nighttime butterfly distribution extend inward. The large southward IMFs can also lead to the azimuthal expansion of the nighttime butterfly distributions. These variations are consistent with the drift shell splitting and/or magnetopause shadowing effect.
Multipoint observations of the structure and evolution of foreshock bubbles and their relation to hot flow anomalies
Authors: Liu Terry Z. , Turner Drew L. , Angelopoulos Vassilis , Omidi Nick 
Published: June 2016

AbstractWhen backstreaming foreshock ions pass through approaching solar wind discontinuities, they may get concentrated upstream of the discontinuities and form foreshock bubbles (FBs). Because FBs result in very intense global pressure variations upstream of and inside Earth's magnetosphere, they are important for solar wind‐magnetosphere coupling. Information about these recently discovered phenomena is limited, however. To elucidate FB spatial structure, evolution, expansion, and formation conditions, we use multipoint Time History of Events and Macroscale Interactions during Substorms observations in which three or more spacecraft observed the same events. From single‐case studies of two foreshock bubbles and one hot flow anomaly (HFA), we demonstrate how we determine FB spatial structure, evolution, and expansion and propose a model to explain these properties. We discuss the different conditions leading to formation of FBs and HFAs. Multiple case studies of six FBs, five HFAs, and one spontaneous HFA show that FBs typically expand faster than HFAs and their expansion speed is likely determined by the solar wind speed.
Evidence of rising and poleward shift of storm surge in western North Pacific in recent decades
Authors: Oey Lie‐Yauw , Chou Simon 
Published: June 2016

AbstractRecently, there has been considerable interest in examining how sea‐level extremes due to storm surge may be related to climate change. Evidence of how storm‐surge extremes have evolved since the start of the most recent warming of mid‐1970s and early 1980s has not been firmly established however. Here we use 64 years (1950–2013) of observations and model simulations, and find evidence of a significant rise in the intensity as well as poleward‐shifting of location of typhoon surges in the western North Pacific after 1980s. The rising and poleward‐shifting trends are caused by the weakening of the steering flow in the tropics, which is related to climate warming, resulting in slower‐moving and longer‐lasting typhoons which had shifted northward.
Using CryoSat‐2 altimeter data to evaluate M2 internal tides observed from multisatellite altimetry
Authors: Zhao Zhongxiang 
Published: June 2016

AbstractThis paper evaluates M2 internal tides observed from multisatellite altimetry (MultiSat20yr) using CryoSat‐2 altimeter data. MultiSat20yr is constructed using 20 years of sea surface height measurements made by multiple satellite altimeters from 1992 to 2012. Here it is demonstrated that M2 internal tides can also be extracted using 4 years of CryoSat‐2 data from 2011 to 2014 (CryoSat4yr) by the same plane wave fit method. MultiSat20yr and CryoSat4yr are in good agreement in the central North Pacific, although they are from satellite data of different sampling patterns (1998 versus 10,688 tracks) and different observational periods (20 versus 4 years). Further comparisons are carried out for three isolated wave components. MultiSat20yr and CryoSat4yr agree very well for both Hawaiian components, suggesting that the Hawaiian Ridge is a relatively stable generation site. In contrast, the Aleutian Ridge is a relatively unstable source in that the M2 amplitudes in MultiSat20yr and CryoSat4yr are very different. With respect to MultiSat20yr, the M2 internal tide in 2011–2014 propagates slower (faster) to the south (north) of Hawaii, respectively, suggesting that the internal tide's propagation speed is subject to significant interannual variability. This feature is supported by M2 internal tides observed using multisatellite altimeter data in 2005 (MultiSat2005) and Argo measured upper ocean temperature profiles. MultiSat20yr is used to correct M2 internal tides in the CryoSat‐2 data. Significant and efficient variance reduction suggests that MultiSat20yr is a reliable internal tide model. A phase‐adjusted MultiSat20yr is built to account for the interannual variations, and it works better in internal tide correction.
Exploiting coastal altimetry to improve the surface circulation scheme over the central Mediterranean Sea
Authors: Jebri Fatma , Birol Florence , Zakardjian Bruno , Bouffard Jérome , Sammari Cherif 
Published: June 2016

AbstractThis work is the first study exploiting along track altimetry data to observe and monitor coastal ocean features over the transition area between the western and eastern Mediterranean Basins. The relative performances of both the AVISO and the X‐TRACK research regional altimetric data sets are compared using in situ observations. Both products are cross validated with tide gauge records. The altimeter‐derived geostrophic velocities are also compared with observations from a moored Acoustic Doppler Current Profiler. Results indicate the good potential of satellite altimetry to retrieve dynamic features over the area. However, X‐TRACK shows a more homogenous data coverage than AVISO, with longer time series in the 50 km coastal band. The seasonal evolution of the surface circulation is therefore analyzed by conjointly using X‐TRACK data and remotely sensed sea surface temperature observations. This combined data set clearly depicts different current regimes and bifurcations, which allows us to propose a new seasonal circulation scheme for the central Mediterranean. The analysis shows variations of the path and temporal behavior of the main circulation features: the Atlantic Tunisian Current, the Atlantic Ionian Stream, the Atlantic Libyan Current, and the Sidra Gyre. The resulting bifurcating veins of these currents are also discussed, and a new current branch is observed for the first time.
Using satellite‐derived optical thickness to assess the influence of clouds on terrestrial carbon uptake
Authors: Cheng S. J. , Steiner A. L. , Hollinger D. Y. , Bohrer G. , Nadelhoffer K. J. 
Published: June 2016

AbstractClouds scatter direct solar radiation, generating diffuse radiation and altering the ratio of direct to diffuse light. If diffuse light increases plant canopy CO2 uptake, clouds may indirectly influence climate by altering the terrestrial carbon cycle. However, past research primarily uses proxies or qualitative categories of clouds to connect the effect of diffuse light on CO2 uptake to sky conditions. We mechanistically link and quantify effects of cloud optical thickness (τc) to surface light and plant canopy CO2 uptake by comparing satellite retrievals of τc to ground‐based measurements of diffuse and total photosynthetically active radiation (PAR; 400–700 nm) and gross primary production (GPP) in forests and croplands. Overall, total PAR decreased with τc, while diffuse PAR increased until an average τc of 6.8 and decreased with larger τc. When diffuse PAR increased with τc, 7–24% of variation in diffuse PAR was explained by τc. Light‐use efficiency (LUE) in this range increased 0.001–0.002 per unit increase in τc. Although τc explained 10–20% of the variation in LUE, there was no significant relationship between τc and GPP (p > 0.05) when diffuse PAR increased. We conclude that diffuse PAR increases under a narrow range of optically thin clouds and the dominant effect of clouds is to reduce total plant‐available PAR. This decrease in total PAR offsets the increase in LUE under increasing diffuse PAR, providing evidence that changes within this range of low cloud optical thickness are unlikely to alter the magnitude of terrestrial CO2 fluxes.
Phosphorescence, Fluorescence, and Chemiluminescence in Clinical Chemistry
Authors: Albani Jihad R. 
Published: June 2016

AbstractSeveral modern aspects of luminescence spectroscopy are considered, especially as they pertain to clinical analysis of endogenous substances and of drugs and their metabolites. Fluorescence and phosphorescence spectroscopies and chemiluminescence methods are compared. For this purpose, application of different dyes is described.
Chromatography in Process Analysis
Authors: Clemons Jerry 
Published: June 2016

Abstract
Process chromatography is an analytical technique that provides for the on‐line separation and measurement of the components of a mixture in a chemical process. The chromatographic analyzers utilized for on‐line analysis must operate in a continuous and automatic manner, taking a fixed quantity of sample, separating the chemical components using adsorption or partitioning columns, and measuring the concentration of each with a detector. The chromatograph provides both quantitative results, by measuring the area of the peak generated as the components pass through the detector, and qualitative results based on the retention time, which is measured from injection to detection.
The most commonly used process chromatographic analyzer is the process gas chromatograph because of its many applications in the hydrocarbon processing industry. A variety of valve, column, and detector configurations are available for these analyses, from parts per million to percent levels. All samples must be in gas phase or must be liquids that can be vaporized before analysis. The analyzers are controlled using a cyclic timing device that switches valves and columns as the components pass through the system to provide the necessary separation. This time cycle is a limitation of the technique for applications requiring continuous or very fast analysis times. Even with these limitations, the advantages of cost, flexibility, sensitivity, and reliability have made process gas chromatography (PGC) the most widely used analytical technique for on‐line process control.
Near‐Infrared Imaging of Polymers; from Basic Science to Industrial Applications
Authors: Shinzawa Hideyuki , Ishikawa Daitaro , Ishigaki Mika , Ozaki Yukihiro 
Published: June 2016

AbstractThis article aims at outlining recent progress in near‐infrared (NIR) imaging particularly for polymer science and engineering. NIR imaging is useful in nondestructive and in situ analysis of various kinds of polymers, even thick films and bulk materials. NIR imaging provides novel information about the spatial distribution of sample components, the distribution of different morphologies or physical properties, and dynamic process such as polymer dissolution. In this article, the characteristics and advantages of NIR imaging are described first and then two newly developed NIR imaging instruments are introduced. Finally, several examples of applications of NIR imaging to polymer science and engineering are discussed.
X
‐Ray Sources for Handheld
X
‐Ray Fluorescence Instruments
Authors: Cornaby Sterling , Kozaczek Kris 
Published: June 2016

Abstract
This article discusses the current status of X‐ray sources (tubes and power supplies) used in handheld X‐ray fluorescence instruments. It outlines the basics of the tube and high‐voltage power supply (HVPS) design and the functionality of X‐ray sources designed specifically for handheld X‐ray fluorescence (XRF). Further, the testing methodologies of the tubes and power supplies are discussed. Finally, the selection criteria for the X‐ray source for common applications are presented.
Using Advanced Correlative Microscopy to Study Complex Biological Samples
Authors: Sueters ‐ Di Meo Josey , Liv Nalan , Hoogenboom Jacob P. 
Published: June 2016

AbstractCorrelation between light, mostly fluorescence, and electron microscopy (EM) is needed to identify biological molecules within their ultrastructural context and/or to relate the ultrastructure to preceding dynamics of biological molecules. Recent development of labels, sample preparation techniques, and microscopy tools allow researchers to bridge the gap between these two modalities, while dedicated, integrated microscopes merge the two techniques into one. This not only allows broader possibilities for implementation of CLEM (correlative light and electron microscopy) in analytical sciences but also enables novel applications crossing boundaries between the traditional microscopes. We provide an overview of the different CLEM approaches, including common labels and sample preparation techniques, and focus attention specifically on the advanced instrumentation and the novel opportunities and challenges these bring for the chemical and biological sciences.
Metabolism‐Based Drug–Drug Interactions in Critically Ill Patients: Clinical Relevance and Predictability ofIn VitroSystems
Authors: Mouly Stéphane , Spriet Isabel , Wauters Joost , Annaert Pieter , Meune Christophe , Bergmann Jean‐François 
Published: June 2016

AbstractDrug–drug interactions (DDIs) contribute mainly to the incidence of adverse drug reactions. Important advances in the knowledge of human drug‐metabolizing enzymes have fueled the integration of in vitro drug metabolism and clinical DDI studies for the use in drug development programs and in the clinical setting. The activities of cytochrome P450 (CYP) 3A4 and P‐glycoprotein are critical determinants of drug clearance and are involved in the mechanism of numerous clinically relevant DDI. Human liver, intestinal samples, and recombinant human CYP3A4 are now available as in vitro screening tools to predict the potential for in vivo DDI. The interpretation and extrapolation of in vitro interaction data to in vivo situations require a good understanding of pharmacokinetic principles. In this chapter, research on drug metabolism and DDI along with examples illustrating the utility of specific in vitro or in vivo approaches is presented. In addition, the impact and clinical relevance of complexities such as dosing‐route‐dependent effects, multisite kinetics of drug‐metabolizing enzymes, and non‐CYP determinants of metabolic clearance are addressed.
Metabolic Characterization of Cell Systems Used inIn VitroToxicology Testing
Authors: Garcia‐Canton Carolina , Minet Emmanuel 
Published: June 2016

AbstractThe use of cell lines is one of the pillars forin vitrotoxicology testing; however, most cell lines lack tissue‐specific metabolic capabilities. The absence of competency to exert physiologically relevant metabolism could lead to a bias in the setting of threshold doses for risk assessment purposes, especially in the context of the consumer product and pharmaceutical industries. Metabolism is therefore a key element and also a limitation in testing ofin vitrotoxicology. In this chapter,in vitrotoxicology models as an alternative to animal testing and the metabolism requirements expected in an optimal cell system have been summarized. The areas that are emerging and that could lead to the development of next‐generationin vitrosystems for toxicology testing, such as stem cells, are also reviewed. Overall, the benefits of clearly establishing the metabolic competency ofin vitrosystems are highlighted. This approach will help us to understand the possible limitations associated with a model that is included as part of a fully integrated human risk assessment strategy.