bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aerodynamic Parameters Over an Eroding Bare Surface: Reconciliation of the Law of the Wall and Eddy Covariance Determinations
Authors: Dupont S. , Rajot J‐L. , Labiadh M. , Bergametti G. , Alfaro S. C. , Bouet C. , Fernandes R. , Khalfallah B. , Lamaud E. , Marticorena B. , Bonnefond J‐M. , Chevaillier S. , Garrigou D. , Henry‐des‐Tureaux T. , Sekrafi S. , Zapf P. 
Published: April 2018

AbstractAssessing accurately the surface friction velocity is a key issue for predicting and quantifying aeolian soil erosion. This is usually done either indirectly from the law of the wall (LoW) of the mean wind velocity profile or directly from eddy covariance (EC) of the streamwise and vertical wind velocity fluctuations. However, several recent experiments have reported inconsistency between friction velocities deduced from both methods. Here we reinvestigate the determination of aerodynamic parameters (friction velocity and surface roughness length) over an eroding bare surface and look at the possible reasons for observing differences on these parameters following the method. For that purpose a novel field experiment was performed in South Tunisia under the research program WIND‐O‐V (WIND erOsion in presence of sparse Vegetation). We find no significant difference between friction velocities obtained from both law of the wall and EC approaches when the friction velocity deduced from the EC method was extrapolated to the surface. Surface roughness lengths show a clear increase with wind erosion, with more scattered values when deduced from the EC friction velocity. Our measurements further suggest an average value of the von Karman constant of 0.407 ± 0.002, although individual wind events lead to different average values due probably to the definition of the ground level or to the stability correction. Importantly, the von Karman constant was found independent of the wind intensity and thus of the wind soil erosion intensity. Finally, our results lead to several recommendations for estimating the aerodynamic parameters over bare surface in order to evaluate saltation and dust fluxes.
Prospects and Caveats of Weighting Climate Models for Summer Maximum Temperature Projections Over North America
Authors: Lorenz Ruth , Herger Nadja , Sedláček Jan , Eyring Veronika , Fischer Erich M. , Knutti Reto 
Published: April 2018

AbstractUncertainties in climate projections exist due to natural variability, scenario uncertainty, and model uncertainty. It has been argued that model uncertainty can be decreased by giving more weight to those models in multimodel ensembles that are more skillful and realistic for a specific process or application. In addition, some models in multimodel ensembles are not independent. We use a weighting approach proposed recently that takes into account both model performance and interdependence and apply it to investigate projections of summer maximum temperature climatology over North America in two regions of different sizes. We quantify the influence of predicting diagnostics included in the method, look at ways how to choose them, and assess the influence of the observational data set used. The trend in shortwave radiation, mean precipitation, sea surface temperature variability, and variability and trend in maximum temperature itself are the most promising constraints on projections of summer maximum temperature over North America. The influence of the observational data sets is large for summer temperature climatology, since the observational and reanalysis products used for absolute maximum temperatures disagree. Including multiple predicting diagnostics leads to more similar results for different data sets. We find that the weighted multimodel mean reduces the change in summer daily temperature maxima compared to the nonweighted mean slightly (0.05–0.45 °C) over the central United States. We show that it is essential to have reliable observations for key variables to be able to constrain multimodel ensembles of future projections.
Remote Sensing of Droplet Number Concentration in Warm Clouds: A Review of the Current State of Knowledge and Perspectives
Authors: Grosvenor Daniel P. , Sourdeval Odran , Zuidema Paquita , Ackerman Andrew , Alexandrov Mikhail D. , Bennartz Ralf , Boers Reinout , Cairns Brian , Chiu J. Christine , Christensen Matthew , Deneke Hartwig , Diamond Michael , Feingold Graham , Fridlind Ann , Hünerbein Anja , Knist Christine , Kollias Pavlos , Marshak Alexander , McCoy Daniel , Merk Daniel , Painemal David , Rausch John , Rosenfeld Daniel , Russchenberg Herman , Seifert Patric , Sinclair Kenneth , Stier Philip , van Diedenhoven Bastiaan , Wendisch Manfred , Werner Frank , Wood Robert , Zhang Zhibo , Quaas Johannes 
Published: April 2018

AbstractThe cloud droplet number concentration (Nd) is of central interest to improve the understanding of cloud physics and for quantifying the effective radiative forcing by aerosol‐cloud interactions. Current standard satellite retrievals do not operationally provide Nd, but it can be inferred from retrievals of cloud optical depth (τc) cloud droplet effective radius (re) and cloud top temperature. This review summarizes issues with this approach and quantifies uncertainties. A total relative uncertainty of 78% is inferred for pixel‐level retrievals for relatively homogeneous, optically thick and unobscured stratiform clouds with favorable viewing geometry. The uncertainty is even greater if these conditions are not met. For averages over 1° ×1° regions the uncertainty is reduced to 54% assuming random errors for instrument uncertainties. In contrast, the few evaluation studies against reference in situ observations suggest much better accuracy with little variability in the bias. More such studies are required for a better error characterization. Nd uncertainty is dominated by errors in re, and therefore, improvements in re retrievals would greatly improve the quality of the Nd retrievals. Recommendations are made for how this might be achieved. Some existing Nd data sets are compared and discussed, and best practices for the use of Nd data from current passive instruments (e.g., filtering criteria) are recommended. Emerging alternative Nd estimates are also considered. First, new ideas to use additional information from existing and upcoming spaceborne instruments are discussed, and second, approaches using high‐quality ground‐based observations are examined.
A Modeling Study of Direct and Indirect N2O Emissions From a Representative Catchment in the U.S. Corn Belt
Authors: Fu Congsheng , Lee Xuhui , Griffis Timothy J. , Baker John M. , Turner Peter A. 
Published: April 2018

AbstractIndirect nitrous oxide (N2O) emissions from drainage ditches and headwater streams are poorly constrained. Few studies have monitored stream N2O emissions and fewer modeling studies have been conducted to simulate stream N2O emissions. In this study, we developed direct and indirect N2O emission modules and a corresponding calibration module for use in the Soil and Water Assessment Tool (SWAT) model, and implemented the expanded SWAT model (termed SWAT‐N2O) to a representative fourth‐stream‐order catchment (210 km2) and six first‐order stream catchments (0.22–1.83 km2) in southeastern Minnesota. We simulated the spatial and temporal fluctuations of the indirect emissions from streams, identified emission “hot spots” and “hot moments,” and diagnosed the correlations between direct and indirect emissions. We showed that zero‐order streams and first‐order streams could contribute 0.034–0.066 and 0.011 nmol N2O m−2 s−1 (expressed on the basis of unit catchment area) to the total surface emissions, respectively. Emissions from zero‐order and first‐order streams equal 24–41% of direct emissions from soil, which may explain the emission gap between calculations using top‐down and bottom‐up methods. Clear spatial patterns were identified for both direct and indirect emissions and their spatial variations were negatively correlated. Our results suggest that the IPCC N2O emission factor for streams in the Corn Belt should be increased by 3.2–5.7 times. Increasing precipitation and streamflow in the Corn Belt may potentially increase frequencies of soil anoxic conditions and nitrate leaching to streams, and subsequently increase N2O emissions from both soils and streams.
SubMachine: Web‐Based Tools for Exploring Seismic Tomography and Other Models of Earth's Deep Interior
Authors: Hosseini Kasra , Matthews Kara J. , Sigloch Karin , Shephard Grace E. , Domeier Mathew , Tsekhmistrenko Maria 
Published: April 2018

AbstractWe present SubMachine, a collection of web‐based tools for the interactive visualization, analysis, and quantitative comparison of global‐scale data sets of the Earth's interior. SubMachine focuses on making regional and global‐scale seismic tomography models easily accessible to the wider solid Earth community, in order to facilitate collaborative exploration. We have written software tools to visualize and explore over 30 tomography models—individually, side‐by‐side, or through statistical and averaging tools. SubMachine also serves various nontomographic data sets that are pertinent to the interpretation of mantle structure and complement the tomographies. These include plate reconstruction models, normal mode observations, global crustal structure, shear wave splitting, as well as geoid, marine gravity, vertical gravity gradients, and global topography in adjustable degrees of spherical harmonic resolution. By providing repository infrastructure, SubMachine encourages and supports community contributions via submission of data sets or feedback on the implemented toolkits.
Development of a Double Hemispherical Probe for Improved Space Plasma Measurements
Authors: Wang X. , Samaniego J. I. , Hsu H.‐W. , Horányi M. , Wahlund J.‐E. , Ergun R. E. , Bering E. A. 
Published: April 2018

AbstractLangmuir probes have been widely used for space plasma measurements for decades. However, there are still challenges in the interpretation of their measurements. Due to the interaction of the ambient plasma with a spacecraft and an onboard probe itself, the local plasma conditions around the probe could be very different from the true ambient plasma of interest. These local plasma conditions are often anisotropic and/or inhomogeneous. Most of the Langmuir probes that are made of a single electrode have difficulties to remove these local plasma effects, introducing errors in the derived plasma characteristics. Directional probes are able to characterize anisotropic and inhomogeneous plasmas. The split Langmuir probe and the Segmented Langmuir Probe have been developed to characterize the plasma flow in the Earth's ionosphere. Here we introduce a new type of a directional Langmuir probe, the Double Hemispherical Probe (DHP), to improve the space plasma measurements in a broad range of scenarios: (a) low‐density plasmas, (b) high surface‐emission (photo and/or secondary electron emission) environments, (c) flowing plasmas, and (d) dust‐rich plasma environments. The DHP consists of two identical hemispheres that are electrically insulated and swept with the same voltages simultaneously. The difference currents between the two hemispheres are used to characterize the anisotropic/inhomogeneous plasma conditions created around the probe, which will be then removed or minimized on the interpretation of their current‐voltage curves. This paper describes the basic concept and design of the DHP sensor, as well as its initial results tested in the laboratory plasma environments.
Hybridization Melting Between Continent‐Derived Sediment and Depleted Peridotite in Subduction Zones
Authors: Wang Yu , Foley Stephen F. 
Published: April 2018

AbstractTo better constrain the processes by which subducted continent‐derived sediment and the overlying mantle wedge react to produce hybrid magmas, we have performed a series of high‐pressure interaction experiments involving a phyllitic metasediment and a depleted peridotite (dunite) from the Mediterranean section of the Alpine‐Himalayan orogenic belt at 2–3 GPa. Two different experimental methods were compared, namely, the reaction of separate, juxtaposed peridotite and metasediment blocks (reaction experiments) and capsules in which the two rocks were included as an intimately mixed powder before the experiments (mixed experiments). In reaction experiments, only the metasediment partially melted, and a marked, thin reaction zone dominated by orthopyroxene formed between the dunite and phyllite blocks. In contrast, a hybrid melt phase was found in all mixed experiments. Trace element analyses indicated that Cs, Rb, Ba, Th, U, Nb, Ta, Zr, and Hf were strongly incompatible, together with marked light rare earth element/heavy rare earth element fractionation. The reaction with peridotite can significantly affect the mobility of medium rare earth element, heavy rare earth element, and transition elements during sediment‐mantle interaction, enriching them in hybrid melts. In addition, the nature of the sedimentary starting materials can considerably affect trace element behavior in resulting hybrid melts. There is a significant resemblance between the trace element distribution patterns of hybrid melts produced in our experiments and those of natural postcollisional potassium‐rich volcanic rocks from the eastern Mediterranean region. The experiments show that phlogopite is not necessarily required in the source to produce the SiO2‐richer end of the range of K‐rich magmas.
The Combined Influence of Observed Southern Ocean Clouds and Sea Ice on Top‐of‐Atmosphere Albedo
Authors: Frey W. R. , Morrison A. L. , Kay J. E. , Guzman R. , Chepfer H. 
Published: April 2018

AbstractWhen sea ice concentration decreases, surface albedo decreases. Yet the impact of Southern Ocean sea ice concentration decreases on top‐of‐atmosphere albedo is uncertain. Why? The cloud cover and opacity response to Southern Ocean sea ice variability has been challenging to quantify. Here we use observations to constrain the cloud response to Southern Ocean sea ice variability and assess the combined influence of sea ice and clouds on top‐of‐atmosphere albedo. We focus on the spring and summer seasons that dominate the high‐latitude shortwave energy budget. To isolate the influence of sea ice concentration on clouds, we analyze spaceborne light detection and ranging (LIDAR) observations in regions where present‐day sea ice concentration varies. During spring, low cloud cover is slightly (4%) higher over open water compared to sea ice. During summer, sea ice variability does not affect low cloud cover. During both spring and summer, cloud opacity is larger over open water than over sea ice due to a cloud phase shift from ice toward liquid with warming. Independent ship‐based visual and radiosonde observations available during summer corroborate the LIDAR results. Even with the cloud response, satellite‐observed top‐of‐atmosphere albedo is lower over open water than over sea ice. The observations show the cloud response to sea ice retreat with warming will not mask the surface albedo decrease. In other words, more shortwave radiation will be absorbed when Southern Ocean sea ice is lost.
Dispersion and Mixing in Three‐Dimensional Discrete Fracture Networks: Nonlinear Interplay Between Structural and Hydraulic Heterogeneity
Authors: Hyman J. D. , Jiménez‐Martínez J. 
Published: April 2018

AbstractWe investigate the relative impact of topological, geometric, and hydraulic heterogeneity on transport processes in three‐dimensional fracture networks. Focusing on the two largest scales of heterogeneity in these systems, individual fracture and network structure, we compare transport through analogous structured and disordered three‐dimensional fracture networks with varying degrees of hydraulic heterogeneity. For the moderate levels of hydraulic heterogeneity we consider, network structure is the dominant control of transport through the networks. Less dispersion, both longitudinal and transverse, is observed in structured networks than in disordered networks, due in part to the higher connectivity in the former, independent of the level of hydraulic heterogeneity. However, increases in dispersion with higher hydraulic heterogeneity are larger in the disordered networks than in the structured networks, thereby indicating that the interplay between structural and hydraulic heterogeneity is nonlinear. We propose a measure of disorder in fracture networks by computing the Shannon entropy of the spectrum of the Laplacian of a weighted graph representation of the networks, where the weights are given by a combination of topological, geometric, and hydraulic properties. This metric, as a relative indicator by comparison between two networks, is a first approach to the dispersion potential and “mixing capacity” of a fracture network.
Lithium-associated transcriptional regulation of CRMP1 in patient-derived olfactory neurons and symptom changes in bipolar disorder
Authors: McLean Charlee K. , Narayan Soumya , Lin Sandra Y. , Rai Narayan , Chung Youjin , Hipolito MariaMananita S. , Cascella Nicola G. , Nurnberger John I , Ishizuka Koko , Sawa Akira S. , Nwulia Evaristus A. 
Published: April 2018

AbstractThere is growing evidence that lithium used in the treatment of bipolar disorder (BD) affects molecular targets that are involved in neuronal growth, survival, and maturation, but it remains unclear if neuronal alterations in any of these molecules predict specific symptom changes in BD patients undergoing lithium monotherapy. The goals of this study were to (a) determine which molecular changes in the olfactory neurons of symptomatic patients receiving lithium are associated with antimanic or antidepressant response, and (b) uncover novel intraneuronal regulatory mechanisms of lithium therapy. Twenty-two treatment-naïve non-smoking patients, with symptomatic BD underwent nasal biopsies for collection of olfactory tissues, prior to their treatment and following a 6-week course of lithium monotherapy. Sixteen healthy controls were also biopsied. Combining laser capture microdissection with real-time polymerase chain reaction, we investigated baseline and treatment-associated transcriptional changes in candidate molecular targets of lithium action in the olfactory neuroepithelium. Baseline mRNA levels of glycogen synthase kinase 3 beta (GSK3β) and collapsin response mediator protein 1 (CRMP1) genes were significantly associated with BD status and with severity of mood symptoms. Among BD subjects, treatment-associated downregulation of CRMP1 expression was most predictive of decreases in both manic and depressive symptoms. This study provides a novel insight into the relevance of CRMP1, a key molecule in semaphorin-3A signaling during neurodevelopment, in the molecular mechanism of action of lithium, and in the pathophysiology of BD. It supports the use of human-derived olfactory neuronal tissues in the evaluation of treatment response of psychiatric disorders.
Electrochemically driven conversion reaction in fluoride electrodes for energy storage devices
Authors: Li Chilin , Chen Keyi , Zhou Xuejun , Maier Joachim 
Published: April 2018

AbstractExploring electrochemically driven conversion reactions for the development of novel energy storage materials is an important topic as they can deliver higher energy densities than current Li-ion battery electrodes. Conversion-type fluorides promise particularly high energy densities by involving the light and small fluoride anion, and bond breaking can occur at relatively low Li activity (i.e., high cell voltage). Cells based on such electrodes may become competitors to other envisaged alternatives such as Li-sulfur or Li-air systems with their many unsolved thermodynamic and kinetic problems. Relevant conversion reactions are typically multiphase redox reactions characterized by nucleation and growth processes along with pronounced interfacial and mass transport phenomena. Hence significant overpotentials and nonequilibrium reaction pathways are involved. In this review, we summarize recent findings in terms of phase evolution phenomena and mechanistic features of (oxy)fluorides at different redox stages during the conversion process, enabled by advanced characterization technologies and simulation methods. It can be concluded that well-designed nanostructured architectures are helpful in mitigating kinetic problems such as the usually pronounced voltage hysteresis. In this context, doping and open-framework strategies are useful. By these tools, simple materials that are unable to allow for substantial Li nonstoichiometry (e.g., by Li-insertable channels) may be turned into electroactive materials.
Mousetap, a Novel Technique to Collect Uncontaminated Vitreous or Aqueous and Expand Usefulness of Mouse Models
Authors: Fortmann Seth D. , Lorenc Valeria E. , Shen Jikui , Hackett Sean F. , Campochiaro Peter A. 
Published: April 2018

AbstractVitreous or aqueous humour taps are widely used in patients or large animals with retinal diseases to monitor disease biomarkers, search for novel biomarkers, assess the integrity of the blood-retinal barrier, or perform pharmacokinetic or pharmacodynamics studies. Although there are many useful mouse models of retinal diseases, the small size of mouse eyes has precluded vitreous or aqueous taps. Herein we describe a novel technique, mousetap, which allows collection of vitreous or aqueous humour uncontaminated by blood or tissue surrounding the vitreous cavity. Mousetap was used to obtain vitreous samples from several mouse models of retinal vascular diseases and vitreous albumin measured by ELISA was highly reproducible among mice of the same model. The mean vitreous albumin concentration differed widely among control mice and mice of different models and correlated with fluorescein angiographic assessment of vascular leakage severity. Protein arrays showed increases in levels of several vasoactive proteins in the vitreous from mice with oxygen-induced ischemic retinopathy compared with age-matched controls; almost all of these proteins are increased in the vitreous of patients with the most common human ischemic retinopathy, proliferative diabetic retinopathy. Thus, mousetap facilitates the use of mice for studies previously reserved for large animal models and patients.
A Study on the Factors Influencing Triglyceride Levels among Adults in Northeast China
Authors: Zhang Anning , Yao Yan , Xue Zhiqiang , Guo Xin , Dou Jing , Lv Yaogai , Shen Li , Yu Yaqin , Jin Lina 
Published: April 2018

AbstractTriglyceride (TG) abnormalities are the most prevalent type of dyslipidaemia in the people of northeast China. Many researchers have investigated the prevalence, treatment and control of TG abnormalities, but little is known about the associations between the TG values and the factors that influence TG levels. This study aims to reveal quantile-specific associations of TG with its risk factors. A sample of 16,340 participants in Jilin Province were included in this study. A quantile regression (QR) model was performed to identify the factors that affected TG levels in different quantiles. The distribution of TG levels was different between males and females (χ
2
= 155.77, P < 0.001). Body mass index (BMI) and waist circumference (WC) were positively associated with TG levels in all quantiles. Drinking was positively associated with TG levels in high quantiles (P70.6 to P95) only in males, while age had a positive association with TG levels in all quantiles only in females. The risk of WC on TG levels was higher with increasing TG levels, and smokers were more at risk for increasing TG levels, as well.