bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preferences for policy attributes and willingness to pay for water quality improvements under uncertainty
Authors: Mullen Jeffrey D. , Calhoun Kayla C. , Colson Gregory J. 
Published: March 2017

AbstractWhen exploring environmental policy options, sometimes neither the current state of the environmental good being analyzed nor the effectiveness of the proposed policy is known with certainty. This is the case with privately owned, residential, onsite wastewater treatment systems (septic systems)—there is ample evidence that they can contribute to water quality impairment, but their contribution is generally stochastic in nature and the efficacy of technological solutions is uncertain. Furthermore, the benefits of ameliorating water quality impairments are public in nature. Septic system owners are legally responsible for maintaining their systems, but requiring them to upgrade otherwise properly functioning tanks is outside the scope of water quality regulations. An incentive structure is necessary to induce private homeowners to invest in septic upgrades that deliver both private benefits in addition to the positive externality for the wider public and environment. The question for policy makers is how these private incentives should be financed, and whether public support can be garnered. Results of a choice experiment in Gwinnett County, Georgia, accounting for both sources of uncertainty—the current state of water quality and the efficacy of the intervention—in the design of water quality policy are presented. We find baseline water quality conditions and policy efficacy significantly affect public support for a policy transferring public funds to private homeowners, in terms of both sentiment and willingness to pay. The manner in which costs are shared across stakeholders also affects the selection of a policy option, but not willingness to pay for it.
Field estimates of groundwater circulation depths in two mountainous watersheds in the western U.S. and the effect of deep circulation on solute concentrations in streamflow
Authors: Frisbee Marty D. , Tolley Douglas G. , Wilson John L. 
Published: March 2017

AbstractEstimates of groundwater circulation depths based on field data are lacking. These data are critical to inform and refine hydrogeologic models of mountainous watersheds, and to quantify depth and time dependencies of weathering processes in watersheds. Here we test two competing hypotheses on the role of geology and geologic setting in deep groundwater circulation and the role of deep groundwater in the geochemical evolution of streams and springs. We test these hypotheses in two mountainous watersheds that have distinctly different geologic settings (one crystalline, metamorphic bedrock and the other volcanic bedrock). Estimated circulation depths for springs in both watersheds range from 0.6 to 1.6 km and may be as great as 2.5 km. These estimated groundwater circulation depths are much deeper than commonly modeled depths suggesting that we may be forcing groundwater flow paths too shallow in models. In addition, the spatial relationships of groundwater circulation depths are different between the two watersheds. Groundwater circulation depths in the crystalline bedrock watershed increase with decreasing elevation indicative of topography‐driven groundwater flow. This relationship is not present in the volcanic bedrock watershed suggesting that both the source of fracturing (tectonic versus volcanic) and increased primary porosity in the volcanic bedrock play a role in deep groundwater circulation. The results from the crystalline bedrock watershed also indicate that relatively deep groundwater circulation can occur at local scales in headwater drainages less than 9.0 km2 and at larger fractions than commonly perceived. Deep groundwater is a primary control on streamflow processes and solute concentrations in both watersheds.
Steady state fractionation of heavy noble gas isotopes in a deep unsaturated zone
Authors: Seltzer Alan M. , Severinghaus Jeffrey P. , Andraski Brian J. , Stonestrom David A. 
Published: March 2017

AbstractTo explore steady state fractionation processes in the unsaturated zone (UZ), we measured argon, krypton, and xenon isotope ratios throughout a ∼110 m deep UZ at the United States Geological Survey (USGS) Amargosa Desert Research Site (ADRS) in Nevada, USA. Prior work has suggested that gravitational settling should create a nearly linear increase in heavy‐to‐light isotope ratios toward the bottom of stagnant air columns in porous media. Our high‐precision measurements revealed a binary mixture between (1) expected steady state isotopic compositions and (2) unfractionated atmospheric air. We hypothesize that the presence of an unsealed pipe connecting the surface to the water table allowed for direct inflow of surface air in response to extensive UZ gas sampling prior to our first (2015) measurements. Observed isotopic resettling in deep UZ samples collected a year later, after sealing the pipe, supports this interpretation. Data and modeling each suggest that the strong influence of gravitational settling and weaker influences of thermal diffusion and fluxes of CO2 and water vapor accurately describe steady state isotopic fractionation of argon, krypton, and xenon within the UZ. The data confirm that heavy noble gas isotopes are sensitive indicators of UZ depth. Based on this finding, we outline a potential inverse approach to quantify past water table depths from noble gas isotope measurements in paleogroundwater, after accounting for fractionation during dissolution of UZ air and bubbles.
Reducing uncertainty with flood frequency analysis: The contribution of paleoflood and historical flood information
Authors: Lam Daryl , Thompson Chris , Croke Jacky , Sharma Ashneel , Macklin Mark 
Published: March 2017

AbstractUsing a combination of stream gauge, historical, and paleoflood records to extend extreme flood records has proven to be useful in improving flood frequency analysis (FFA). The approach has typically been applied in localities with long historical records and/or suitable river settings for paleoflood reconstruction from slack‐water deposits (SWDs). However, many regions around the world have neither extensive historical information nor bedrock gorges suitable for SWDs preservation and paleoflood reconstruction. This study from subtropical Australia demonstrates that confined, semialluvial channels such as macrochannels provide relatively stable boundaries over the 1000–2000 year time period and the preserved SWDs enabled paleoflood reconstruction and their incorporation into FFA. FFA for three sites in subtropical Australia with the integration of historical and paleoflood data using Bayesian Inference methods showed a significant reduction in uncertainty associated with the estimated discharge of a flood quantile. Uncertainty associated with estimated discharge for the 1% Annual Exceedance Probability (AEP) flood is reduced by more than 50%. In addition, sensitivity analysis of possible within‐channel boundary changes shows that FFA is not significantly affected by any associated changes in channel capacity. Therefore, a greater range of channel types may be used for reliable paleoflood reconstruction by evaluating the stability of inset alluvial units, thereby increasing the quantity of temporal data available for FFA. The reduction in uncertainty, particularly in the prediction of the ≤1% AEP design flood, will improve flood risk planning and management in regions with limited temporal flood data.
Flow resistance and hydraulic geometry in contrasting reaches of a bedrock channel
Authors: Ferguson R. I. , Sharma B. P. , Hardy R. J. , Hodge R. A. , Warburton J. 
Published: March 2017

AbstractAssumptions about flow resistance in bedrock channels have to be made for mechanistic modeling of river incision, paleoflood estimation, flood routing, and river engineering. Field data on bedrock flow resistance are very limited and calculations generally use standard alluvial‐river assumptions such as a fixed value of Manning's n. To help inform future work, we measured how depth, velocity, and flow resistance vary with discharge in four short reaches of a small bedrock channel, one with an entirely rock bed and the others with 20–70% sediment cover, and in the alluvial channel immediately upstream. As discharge and submergence increase in each of the partly or fully alluvial reaches there is a rapid increase in velocity and a strong decline in both n and the Darcy‐Weisbach friction factor f. The bare‐rock reach follows a similar trend from low to medium discharge but has increasing resistance at higher discharges because of the macroroughness of its rock walls. Flow resistance at a given discharge differs considerably between reaches and is highest where the partial sediment cover is coarsest and most extensive. Apart from the effect of rough rock walls, the flow resistance trends are qualitatively consistent with logarithmic and variable‐power equations and with nondimensional hydraulic geometry, but quantitative agreement using sediment D84 as the roughness height is imperfect.
Evolution of electron phase space holes in inhomogeneous magnetic fields
Authors: Kuzichev I. V. , Vasko I. Y. , Agapitov O. V. , Mozer F. S. , Artemyev A. V. 
Published: March 2017

AbstractElectron phase space holes (EHs) are electrostatic solitary waves that are widely observed in the space plasma often permeated by inhomogeneous magnetic fields. Understanding of the EH evolution in inhomogeneous magnetic fields is critical for accurate interpretations of spacecraft data. To study this evolution, we use 1.5‐D gyrokinetic electrostatic Vlasov code (magnetized electrons and immobile ions) with periodic boundary conditions. We find that EHs propagating into stronger (weaker) magnetic field are decelerated (accelerated) with deceleration (acceleration) rate dependent on the magnetic field gradient. Remarkably, decelerating EHs are reflected at the magnetic field dependent only on EH parameters (independent of the magnetic field gradient). A magnetic field inhomogeneity results in development of a net potential drop along EHs. Our simulations suggest that slow EHs recently observed in the plasma sheet boundary layer can appear due to braking of initially fast EHs by magnetic field gradients and that a large number of even fast EHs can contribute to macroscopic parallel potential drops.
Dynamics of upwelling annual cycle in the equatorial Atlantic Ocean
Authors: Wang Li‐Chiao , Jin Fei‐Fei , Wu Chau‐Ron , Hsu Huang‐Hsiung 
Published: March 2017

AbstractThe annual upwelling is an important component of the equatorial Atlantic annual cycle. A simple theory is proposed using the framework of Zebiak‐Cane (ZC) ocean model for insights into the dynamics of the upwelling annual cycle. It is demonstrated that in the Atlantic equatorial region this upwelling is dominated by Ekman processing in the west, whereas in the east it is primarily owing to shoaling and deepening of the thermocline resulting from equatorial mass meridional recharge/discharge and zonal redistribution processes associated with wind‐driven equatorial ocean waves. This wind‐driven wave upwelling plays an important role in the development of the annual cycle in the sea surface temperature of the cold tongue in the eastern equatorial Atlantic.
Reply to comment by Melsen et al. on “Most computational hydrology is not reproducible, so is it really science?”
Authors: Hutton Christopher , Wagener Thorsten , Freer Jim , Han Dawei , Duffy Chris , Arheimer Berit 
Published: March 2017

AbstractIn this article, we reply to a comment made by Melsen et al. [2017] on our previous commentary regarding reproducibility in computational hydrology. Re‐executing someone else's code and workflow to derive a set of published results does not by itself constitute reproducibility. However, it forms a key part of the process: it demonstrates that all the degrees of freedom and choices made by the scientist in running the experiment are contained within that code and workflow. This does not only allow us to build and extend directly from the original work, but with full knowledge of decisions made in the original experimental setup, we can then focus our attention to the degrees of freedom of interest: those that occur in hydrological systems that are ultimately our subject of study.
Recent Advances in Organic Reactions Involving Elemental Sulfur
Authors: Nguyen Thanh Binh 
Published: March 2017

AbstractElemental sulfur has been known since Antiquity and found widespread applications in the preparation of black gunpowder, the synthesis of sulfuric acid as well as other sulfur‐containing compounds, and the vulcanization of rubber. Over the last several years, we have come to better understand its properties and discover more applications of elemental sulfur in synthetic organic chemistry. This review summarizes the advances from 2000 in the construction of organic molecules using elemental sulfur via sulfuration, oxidation, reduction and redox condensation processes.magnified image
Shape change and obesity prevalence among male UK offshore workers after 30 years: New insight from a 3D scanning study
Authors: Stewart Arthur D. , Ledingham Robert L. , Furnace Graham , Williams Hector , Nevill Alan M. 
Published: March 2017

AbstractObjectivesIn 1984, male UK offshore workers had greater overweight and obesity prevalence and fat content than the general population. Since then, body weight has increased by 19%, but, without accompanying anthropometric measures, their size increase, current obesity, and fatness prevalence remain unknown. This study therefore aimed to acquire contemporary anthropometric data, profile changes since the original survey, and assess current obesity prevalence in the male offshore workforce.MethodsA total of 588 men, recruited via quota sampling to match the workforce weight profile, underwent stature, weight, and 3D photonic scanning measurements from which anatomical girths were extracted, enabling computation of body mass index (BMI), total fat, and visceral adipose tissue (VAT).ResultsOn average, UK male offshore workers are now 8.1 y older, 3.1 cm taller, 13.9 kg heavier, and have greater girths than in 1984, which are >97% attributable to increased weight, and <3% to age difference. Mean BMI increased significantly from 24.9 to 28.1 kg/m2 and of the contemporary sample, 18% have healthy weight, 52% are overweight, and 30% obese, representing an increase in overweight and obesity prevalence by 6% and 24%, respectively. Waist cutoffs identify 39% of the contemporary sample as healthy, 27% at increased health risk, and 34% at high risk.ConclusionsUK offshore workers today have higher BMI than Scottish men, although some muscular individuals may be misclassified by BMI. Girth data, particularly at the waist, where dimensional increase was greatest, together with predictions of total and visceral fatness, suggest less favorable health status in others.
Heterogeneous Cu‐MnO‐Catalyzed Direct C−H Amination of Azoles Using O2 as the Sole Oxidant
Authors: Singh Harshvardhan , Pal Provas , Sen Chiranjit , Panda Asit B. , Ghosh Subhash Chandra 
Published: March 2017

AbstractAn efficient heterogeneous catalytic method for the oxidative amination of azoles with amines has been developed. This environmentally benign amination reaction was carried out without using any external base or acid, and only molecular oxygen was used as a green oxidant. The catalyst was easily separated from the reaction mixture and reused several times. The aminated azoles are important pharmacophores with biological activity.
Fluorodeoxyglucose metabolism associated with tau‐amyloid interaction predicts memory decline
Authors: Hanseeuw Bernard J. , Betensky Rebecca A. , Schultz Aaron P. , Papp Kathryn V. , Mormino Elizabeth C. , Sepulcre Jorge , Bark John S. , Cosio Danielle M. , LaPoint Molly , Chhatwal Jasmeer P. , Rentz Dorene M. , Sperling Reisa A. , Johnson Keith A. 
Published: March 2017

ObjectiveThe aim of this article was to evaluate in normal older adults and preclinical Alzheimer's disease (AD) the impact of amyloid and regional tauopathy on cerebral glucose metabolism and subsequent memory decline.MethodsWe acquired positron emission tomography using F18 flortaucipir (tau), C11 Pittsburgh compound B (amyloid), and F18 fluorodeoxyglucose (FDG) in 90 clinically normal elderly of the Harvard Aging Brain Study.ResultsPosterior cingulate metabolism decreased when both amyloid and neocortical tau were high and predicted subsequent memory decline in a larger sample of normal elderly. In contrast, frontal hypometabolism related to the common age‐related entorhinal tauopathy, but this dysfunction was independent of amyloid, and did not predict significant memory decline. Neocortical tauopathy was positively associated with metabolism in individuals with subthreshold amyloid, suggesting that glucose metabolism increases before decreasing in the course of preclinical AD.InterpretationOur study identified a synergistic effect of amyloid and tau deposits and demonstrated, for the first time, in normal elderly its link to AD‐like hypometabolism and to AD‐like memory decline. The amyloid effect was observed with tau in neocortex, but not with tau in entorhinal cortex, which is the common site of age‐related tauopathy. Entorhinal tau was associated with frontal hypometabolism, but this dysfunction was not associated with memory loss. Ann Neurol 2017;81:583–596
19F‐NMR Reveals the Role of Mobile Loops in Product and Inhibitor Binding by the São Paulo Metallo‐β‐Lactamase
Authors: Abboud Martine I. , Hinchliffe Philip , Brem Jürgen , Macsics Robert , Pfeffer Inga , Makena Anne , Umland Klaus‐Daniel , Rydzik Anna M. , Li Guo‐Bo , Spencer James , Claridge Timothy D. W. , Schofield Christopher J. 
Published: March 2017

AbstractResistance to β‐lactam antibiotics mediated by metallo‐β‐lactamases (MBLs) is a growing problem. We describe the use of protein‐observe 19F‐NMR (PrOF NMR) to study the dynamics of the São Paulo MBL (SPM‐1) from β‐lactam‐resistant Pseudomonas aeruginosa. Cysteinyl variants on the α3 and L3 regions, which flank the di‐ZnII active site, were selectively 19F‐labeled using 3‐bromo‐1,1,1‐trifluoroacetone. The PrOF NMR results reveal roles for the mobile α3 and L3 regions in the binding of both inhibitors and hydrolyzed β‐lactam products to SPM‐1. These results have implications for the mechanisms and inhibition of MBLs by β‐lactams and non‐β‐lactams and illustrate the utility of PrOF NMR for efficiently analyzing metal chelation, identifying new binding modes, and studying protein binding from a mixture of equilibrating isomers.
An Efficient Iron(III)‐Catalyzed Aerobic Oxidation of Aldehydes in Water for the Green Preparation of Carboxylic Acids
Authors: Yu Han , Ru Shi , Dai Guoyong , Zhai Yongyan , Lin Hualin , Han Sheng , Wei Yongge 
Published: March 2017

AbstractThe first example of a heterogeneous iron(III)‐catalyzed aerobic oxidation of aldehydes in water was developed. This method utilizes 1 atmosphere of oxygen as the sole oxidant, proceeds under extremely mild aqueous conditions, and covers a wide range of various functionalized aldehydes. Chromatography is generally not necessary for product purification. Its operational simplicity, gram‐scale oxidation, and the ability to successively reuse the catalyst, make this new methodology environmentally benign and cost effective. The generality of this methodology gives it the potential to be used on an industrial scale.
Reagens‐ und metallfreie anodische C‐C‐Kreuzkupplung von Anilinderivaten
Authors: Schulz Lara , Enders Mathias , Elsler Bernd , Schollmeyer Dieter , Dyballa Katrin M. , Franke Robert , Waldvogel Siegfried R. 
Published: March 2017

AbstractVorgestellt wird die oxidative Kreuzkupplung von Anilinderivaten zu 2,2′‐Diaminobiarylen. Der Oxidationsschritt wird elektrochemisch durchgeführt, ohne die Notwendigkeit von Metallen und Reagenzien. Ein breites Spektrum an Biphenyldiaminen konnte hergestellt werden. Die besten Resultate wurden mit Glaskohlenstoff als Anodenmaterial erhalten. Die elektrochemische Umsetzung kann problemlos in einer ungeteilten Zelle bei leicht erhöhten Temperaturen durchgeführt werden. Außerdem wurden gebräuchliche, auf Carbonsäuren basierende, Schutzgruppen verwendet, die nach der Kreuzkupplung unter milden Bedingungen selektiv abgespalten werden können. Auf diese Weise erhält man schnell und effizient Zugang zu äußerst wichtigen Bausteinen.
16‐Gliedriger Au8P8‐Makrocyclus aus Gold(I) und Diphospha(III)‐guanidin
Authors: Adhikari Anup K. , Sárosi Menyhárt B. , Grell Toni , Lönnecke Peter , Hey‐Hawkins Evamarie 
Published: March 2017

AbstractDie Reaktion von cyclo‐P4Mes4C(NCy) (1) mit zwei Äquivalenten [AuCl(tht)] (tht=Tetrahydrothiophen) führte zur Bildung des ungewöhnlichen 16‐gliedrigen Au‐P‐Makrocyclus 2. Der Makrocyclus weist Diphospha(III)‐guanidinat‐Liganden auf, die durch Spaltung der P‐P‐Bindungen in 1 gebildet werden. Die Charakterisierung von 2 erfolgte durch Multikern‐NMR‐Spektroskopie, Massenspektrometrie und Röntgenkristallstrukturanalyse.
Fluorooxoborates: Beryllium‐Free Deep‐Ultraviolet Nonlinear Optical Materials without Layered Growth
Authors: Zhang Bingbing , Shi Guoqiang , Yang Zhihua , Zhang Fangfang , Pan Shilie 
Published: March 2017

AbstractDeep‐ultraviolet nonlinear optical (DUV NLO) crystals are the key materials to extend the output range of solid‐state lasers to below 200 nm. The only practical material KBe2BO3F2 suffers high toxicity through beryllium and strong layered growth. Herein, we propose a beryllium‐free material design and synthesis strategy for DUV NLO materials. Introducing the (BO3F)4−, (BO2F2)3−, and (BOF3)2− groups in borates could break through the fixed 3D B–O network that would produce a larger birefringence without layering and simultaneously keep a short cutoff edge down to DUV. The theoretical and experimental studies on a series of fluorooxoborates confirm this strategy. Li2B6O9F2 is identified as a DUV NLO material with a large second harmonic generation efficiency (0.9×KDP) and a large predicted birefringence (0.07) without layering. This study provides a feasible way to break down the DUV wall for NLO materials.
Spectroscopic Evidence for a Monomeric Copper(I) Hydride and Crystallographic Characterization of a Monomeric Silver(I) Hydride
Authors: Romero Erik A. , Olsen Pauline M. , Jazzar Rodolphe , Soleilhavoup Michele , Gembicky Milan , Bertrand Guy 
Published: March 2017

Abstract(1,3‐bis[2,6‐bis[di(4‐tert‐butylphenyl)methyl]‐4‐methylphenyl]imidazol‐2‐ylidene)CuOPh [(IPr**)CuOPh] reacts with poly(methylhydrosiloxane) as the hydride donor to afford the monomeric (IPr**)CuH complex, which was spectroscopically characterized. The latter is in equilibrium in solution with [(IPr**)CuH]2, the dimer being exclusively present in the solid state. These results support the hypothesis that copper hydride aggregates dissociate in solution. In contrast, addition of pinacolborane to [(IPr**)AgOPh] at −40 °C allows the isolation of the monomeric (IPr**)AgH complex, which was crystallographically characterized.