bluuebunny/crossref_metadata_2025_split huggingface dataset:
Persistence and Corresponding Time Scales of Soil Moisture Dynamics During Summer in the Babao River Basin, Northwest China
Authors: shen Shi , Ye Sijing , Cheng Changxiu , Song Changqing , Gao Jianbo , Yang Jing , Ning Lixin , Su Kai , Zhang Ting 
Published: July 2018

AbstractSoil moisture (SM) is an essential Earth surface and climate system variable. Insights into its persistence and corresponding time scales can improve numerical modeling and climate system prediction. In this study, SM from 17 observation stations within the Babao River Basin, Northwest China, between 1 June and 31 August 2014 were used to investigate persistence and corresponding time scales via adaptive fractal analysis. By conducting an adaptive fractal analysis of net radiation and by estimating the complementary cumulative distribution function of precipitation intervals, the relation between meteorological factors and the persistence and time scales of SM are determined and discussed. Results show that persistence and corresponding time scales of SM could be described using a three‐phase concept diagram. (1) At short time scales (approximately 0–14 hr [4 cm], 0–15 hr [10 cm], or 0–19 hr [20 cm]), the persistence of SM at most observation stations shows a strong long‐range correlation or nonstationarity. This phenomenon is essentially due to evaporation influenced by net radiation processes and the effects of rain. (2) At moderate time scales (approximately 14–159 hr [4 cm], 15–161 hr [10 cm], or 19–143 hr [20 cm]), the persistence of SM mostly exhibits a weak long‐range correlation or antipersistence due to net radiation process uncertainty and the probability of precipitation. (3) At long time scales (approximately greater than 159 hr [4 cm], 161 hr [10 cm], and 143 hr [20 cm]), the persistence of SM dynamics exhibits antipersistence because a high probability of precipitation reverses changes in the SM persistence.
Impacts of Snow Darkening by Deposition of Light‐Absorbing Aerosols on Hydroclimate of Eurasia During Boreal Spring and Summer
Authors: Lau William K. M. , Sang Jeong , Kim M. K. , Kim K. M. , Koster R. D. , Yasunari T. J. 
Published: July 2018

AbstractIn this study, we used the NASA GEOS‐5 climate model to investigate the impact of snow darkening by deposition of light‐absorbing aerosols on the hydroclimate of Eurasia during boreal spring and summer. Two sets of 10‐member ensemble model integrations with prescribed sea surface temperature were carried out for 10 simulated years (2002–2011); one includes snow‐darkening effects (SDE) by light‐absorbing aerosols and one does not (NSDE). Differences between the two experiments in the hydroclimates over Eurasia were evaluated. Results show that SDE warming is most pronounced during the melting season due to strong snow‐albedo feedback in the vicinity of the retreating seasonal snowline. SDE spurs a wet‐first‐dry‐later modulation of the surface energy and water balances, characterized by an accelerated (days‐to‐weeks) snowmelt, accompanied by excessive runoff and a warming and wetting of the land (relative to NSDE) during the early melting season. The snowmelt is followed by a fast desiccation of the land during the late melting, and early warming season, and then a prolonged warmer and drier land, through the boreal summer. The prolonged warming is sustained by atmospheric conditions favorable for the development of atmospheric blocking, that is, higher middle‐to‐upper‐tropospheric geopotential height, lower relative humidity, reduced cloudiness, and enhanced atmospheric subsidence. Overall, SDE by light‐absorbing aerosols leads to a warmer and drier boreal summer hydroclimate, increasing the frequency of the top 5 and 1% extreme hot days (as defined by NSDE statistics) over western and northern Eurasia by approximately threefold and tenfold, respectively.
A Lagrangian Model Diagnosis of Stratospheric Contributions to Tropical Midtropospheric Air
Authors: Tao M. , Pan L. L. , Konopka P. , Honomichl S. B. , Kinnison D. E. , Apel E. C. 
Published: July 2018

AbstractAirborne in situ observations during the Convective Transport of Active Species in the Tropics campaign in January–February 2014 revealed a large region over the tropical western Pacific where the midtroposphere had a layered structure with a distinct chemical signature of high ozone and low water vapor (HOLW). The observed anticorrelation between ozone and water vapor is a strong indication of transport from the midlatitude upper troposphere and lower stratosphere. This work presents a diagnosis of stratospheric air in the tropical western Pacific midtroposphere through isentropic transport and mixing. Using the Chemical Lagrangian Model of the Stratosphere, we characterize and quantify the contribution of transported stratospheric air to the observed HOLW layers. The result indicates that the isentropic transport is an effective process for stratospheric air to mix into the tropical midtroposphere. Using the modeled stratospheric tracer and 3‐D back trajectories, we identified that 60% of the observed HOLW air masses contain significant stratospheric influence. We have also examined possible contribution to the HOLW layer from ozone production related to biomass burning emissions. Clear chemical signature of this process is found in ∼8% of the HOLW air masses, identified by positive correlations among O3, HCN, and CO. This analysis provides the first quantitative diagnosis of the contribution from the stratosphere‐to‐troposphere transport, highlights the importance of mixing in chemical transport, and demonstrates the limitations of pure Lagrangian trajectory calculations in quantifying transport.
Future Projections of the Large‐Scale Meteorology Associated with California Heat Waves in CMIP5 Models
Authors: Palipane Erool , Grotjahn Richard 
Published: July 2018

AbstractPrevious work showed that climate models capture historical large‐scale meteorological patterns (LSMPs) associated with California Central Valley heat waves including both ways these heat waves form. This work examines what models predict under the Representative Concentration Pathway (RCP) 4.5 and RCP8.5 scenarios. Model performance varies, so a multimodel average weights each model based on its historical performance in four parameters. An LSMP index (LSMPi) defined using upper atmosphere variables captures dates of past extreme surface temperature maxima. LSMPi correlates well with all values of California Central Valley‐average surface maximum temperature. LSMPi distributions in future simulations shift ~0.6 standard deviations higher between 1961–2000 and 2061–2100 for RCP8.5 data. Based on the historical climatology, future scenarios show a large increase in the frequency and duration of heat waves in every model. Four times as many heat waves occur and their median duration doubles, using historical thresholds. Of the two ways heat waves form, Type 1 has similar frequency in the future. But, Type 2 becomes much more common because Type 2 has a preexisting hot anomaly in Southwestern Canada, much like the historical to future climatological change in that region (a “global warming” signal). The 20‐year return value anomaly increases by 30–40%. The average of the 50 hottest temperatures increases 3.5–6 K depending on the scenario. When extreme values are defined using the future climatology, the models and their average have no consistent increase or decrease of distribution properties such as shape, scale, and return values of the extremes compared to historical values.
Coralline Algae Archive Fjord Surface Water Temperatures in Southwest Greenland
Authors: Williams Siobhan , Halfar Jochen , Zack Thomas , Hetzinger Steffen , Blicher Martin , Juul‐Pedersen Thomas , Kronz Andreas , Noël Brice , van den Broeke Michiel , van de Berg Willem Jan 
Published: July 2018

AbstractOne of the most dramatic signs of ongoing global change is the mass loss of the Greenland Ice Sheet and the resulting rise in sea level, whereby most of the recent ice sheet mass loss can be attributed to an increase in meltwater runoff. The retreat and thinning of Greenland glaciers has been caused by rising air and ocean temperatures over the past decades. Despite the global scale impact of the changing ice sheet balance, estimates of glacial runoff in Greenland rarely extend past several decades, thus limiting our understanding of long‐term glacial response to temperature. Here we present a 42‐year long annually resolved red coralline algal Mg/Ca proxy temperature record from a southwestern Greenland fjord, with temperature ranging from 1.5 to 4 °C (standard error = 1.06 °C). This temperature time series in turn tracks the general trend of glacial runoff from four West Greenland glaciers discharging freshwater into the fjord (all p < 0.001). The algal time series further exhibits significant correlations to Irminger Sea temperature patterns, which are transmitted to western Greenland fjords via the West Greenland Current. The 42‐year long record demonstrates the potential of annual increment forming coralline algae, which are known to live up to 650 years and which are abundant along the Greenland coastline, for reconstructing time series of sea surface temperature.
Organic Carbon Processing During Transport Through Boreal Inland Waters: Particles as Important Sites
Authors: Attermeyer Katrin , Catalán Núria , Einarsdottir Karolina , Freixa Anna , Groeneveld Marloes , Hawkes Jeffrey A. , Bergquist Jonas , Tranvik Lars J. 
Published: July 2018

AbstractThe degradation and transformation of organic carbon (C) in inland waters result in significant CO2 emissions from inland waters. Even though most of the C in inland waters occurs as dissolved organic carbon (DOC), studies on particulate organic carbon (POC) and how it influences the overall reactivity of organic C in transport are still scarce. We sampled 30 aquatic ecosystems following an aquatic continuum including peat surface waters, streams, rivers, and lakes. We report DOC and POC degradation rates, relate degradation patterns to environmental data across these systems, and present qualitative changes in dissolved organic matter and particulate organic matter during degradation. Microbial degradation rates of POC were approximately 15 times higher compared to degradation of DOC, with POC half‐lives of only 17 ± 3 (mean ± SE) days across all sampled aquatic ecosystems. Rapid POC decay was accompanied by a shift in particulate C:N ratios, whereas dissolved organic matter composition did not change at the time scale of incubations. The faster degradation of the POC implies a constant replenishment to sustain natural POC concentrations. We suggest that degradation of organic matter transported through the inland water continuum might occur to a large extent via transition of DOC into more rapidly cycling POC in nature, for example, triggered by light. In this way, particles would be a dominant pool of organic C processing across the boreal aquatic continuum, partially sustained by replenishment via flocculation of DOC.
Low spatial structure and selection against secreted virulence factors attenuates pathogenicity in Pseudomonas aeruginosa
Authors: Granato Elisa T , Ziegenhain Christoph , Marvig Rasmus L , Kümmerli Rolf 
Published: July 2018

Abstract
Bacterial opportunistic pathogens are feared for their difficult-to-treat nosocomial infections and for causing morbidity in immunocompromised patients. Here, we study how such a versatile opportunist, Pseudomonas aeruginosa, adapts to conditions inside and outside its model host Caenorhabditis elegans, and use phenotypic and genotypic screens to identify the mechanistic basis of virulence evolution. We found that virulence significantly dropped in unstructured environments both in the presence and absence of the host, but remained unchanged in spatially structured environments. Reduction of virulence was either driven by a substantial decline in the production of siderophores (in treatments without hosts) or toxins and proteases (in treatments with hosts). Whole-genome sequencing of evolved clones revealed positive selection and parallel evolution across replicates, and showed an accumulation of mutations in regulator genes controlling virulence factor expression. Our study identifies the spatial structure of the non-host environment as a key driver of virulence evolution in an opportunistic pathogen.
Design of tri‐band bandpass filter using symmetrical open stub loaded step impedance resonator
Authors: AbdulRehman M. , Khalid S. 
Published: August 2018

A tri‐band bandpass filter design by using conventional stub loaded step impedance resonator (SLSIR) is presented. The proposed SLSIR consists of three tri‐loaded open‐circuited stubs parallel attached to a short and open‐circuited stub. A tri‐band bandpass filter is designed using two proposed symmetrical SLSIR's separated by a short‐circuited stub. In this configuration, the filter produces three bands of frequencies at 0.9, 2.4 and 5.5 GHz, respectively. It is shown that the resonating frequencies can be independently controlled by loaded stubs. For better out of band rejection and increased selectivity, four finite frequency transmission zeros around three passband edges are achieved. The obtained fractional bandwidths are 23, 10 and 17% centred at 0.9, 2.4 and 5.5 GHz, respectively. The proposed design topology is fabricated on a substrate RT/Duroid 5880. The simulated and measured results show good accordance. The fabricated prototype has a compact size of at 0.9 GHz.
DAB modulation schema with extended ZVS region for applications with wide input/output voltage
Authors: Garcia‐Bediaga Asier , Villar Irma , Rujas Alejandro , Mir Luis 
Published: July 2018

This study is focused on modulation strategies and soft‐switching techniques of the isolated dual‐active‐bridge (DAB) converter for power‐electronics applications, where wide input/output voltage and power ranges are required. The aim of this work is to study the different operation modes and to propose a modulation schema combining five operation modes. The objective of the proposed control strategy is to reduce the switching losses of semiconductors and to improve the overall converter efficiency. Thanks to the use of the single‐active‐bridge modulation, the zero‐voltage‐switching (ZVS) region of the DAB topology is extended, achieving high‐efficiency levels in a wide operation range, even with output voltages close to zero. New analytical expressions are presented in this study to model accurately the behaviour of the DAB converter operation in this extended ZVS region. The influence of non‐dissipative snubbers is also studied including experimental measurements with an insulated gate bipolar transistor‐based 10 kW prototype for the validation of the theoretical study.
Non‐intrusive parameter estimation method for autotuned DC–DC converter based on quasi‐impulse response
Authors: Ali Majid , Loo Ka‐Hong , Lai Yuk‐Ming 
Published: July 2018

A non‐intrusive method to estimate the values of power‐stage components online and autotuning of feedback compensator for digitally controlled power converters is presented in this study. By using buck converter as an example, the presented autotuning controller has been designed to cover the wide‐range variations in equivalent series resistance zero of the output capacitor and the resonant frequency of output filter . These two frequencies are estimated by examining the converter's quasi‐impulse response during start‐up and by measuring the output‐voltage ripple during steady‐state operation of the converter. Hence, due to the non‐intrusive characteristic of the proposed control method, the operation of the converter is not affected. Using the acquired results, the online digital compensator is tuned automatically based on predefined crossover frequency and phase margin to provide the required output‐voltage regulation and transient response under wide‐range variations in the power‐stage component values. To validate the effectiveness of the proposed control method, experimental results from a 12 to 1.5 V buck converter are presented.
Zur Anwendung der Ballon-Kyphoplastie/Vertebroplastie
Authors: Amling M. , Baier M. , Blattert T. , Euler E. , Götte S. , Kaps P. , Kasperk H. , Kurth A. , Meeder P.-J. , Schwarz H. , Steinleitner W. E. , Weißkopf M. , Haas H. ,   Vorsitzender der Autorengruppe
Published: August 2018

ZusammenfassungIn der Behandlung osteoporotischer Wirbelkörperfrakturen finden die minimalinvasiven Methoden der Ballon-Kyphoplastie und der Vertebroplastie zunehmende Verbreitung. In der aktuellen Leitlinie zur Behandlung der Osteoporose ist aufgrund der eingeschränkten Studienlage eine sehr konservative Aussage zur Anwendung der Verfahren getroffen worden. Die vorliegende Arbeit stellt eine Bewertung beider Verfahren hinsichtlich Indikation, technischer Durchführung und notwendiger Voraussetzungen dar. Sie wurde erstellt durch eine vom DVO beauftragte Arbeitsgruppe und soll bestehende Unsicherheiten im Zusammenhang mit beiden Verfahren reduzieren.
Knochenmetastasen
Authors: Ebert R. , Rauner M. , Rachner T. , Schütze N. , Glüer C.-C. , Hofbauer L. C. , Jakob F. ,   für das SkelMet Konsortium
Published: August 2018

ZusammenfassungKnochenmetastasen sind ein klinisch relevantes Problem und ihre Inzidenz nimmt zu. Die Fähigkeit von Tumorzellen, in den Knochen zu metastasieren, erfordert zellbiologische Veränderungen, die zur Migration und zur aktiven Überwindung von Barrieren wie Basalmembranen und Extrazellulärmatrix befähigen. Das „Homing” im Knochen findet dann statt, wenn Tumorzellen dort anheften und gut überleben können. Die Interaktion der beteiligten Zelltypen bewirkt eine Änderung des Phänotyps in allen Partnern einer solchen „malignen Konversation”. Die resultierende Signatur ist oft permanent und führt auf der einen Seite zu einer Suszeptibilität des Stromas für die Metastasierung und auf der anderen Seite zu einer starken Veränderung der Tumorbiologie, die sich vom Primärtumor wesentlich unterscheidet. In einem klassischen Circulus vitiosus können Tumorzellen direkt und indirekt Osteoklasten stimulieren und Osteolysen verursachen. Auf die Osteoblastenfunktion können sie zweierlei Auswirkungen haben. Sie können die Mineralisierung stark stimulieren und damit osteoblastische Metastasen verursachen, sie können aber auch starke Hemmstoffe der Knochenregeneration ausschütten, die eine Osteoplegie hervorrufen, ein völliges Lahm legen der Knochenregeneration. Die Kombination aus Osteolyse und Osteoplegie führt klinisch zu einer besonders schwerwiegenden Situation des Knochenverlusts mit pathologischen Frakturen. Die geschützten Stammzellnischen des Knochenmarks sind auch für Tumorzellen eine gute Möglichkeit zum Überleben. Tumorzellen können sich diese Nischen selbst induzieren. Sie können sich dabei in Richtung Tumorstammzelle verändern und können später zum Ausgangspunkt von Tumorrezidiven werden. Es ist daher für die Zukunft sinnvoll, den Knochen und das Knochenmark als therapeutische Zielstrukturen in onkologische Therapiekonzepte einzubeziehen.
Correlation-based feature optimization and object-based approach for distinguishing shallow and deep-seated landslides using high resolution airborne laser scanning data
Authors: Rmezaal M , Pradhan B 
Published: July 2018

Abstract
Landslides post great threats to many regions globally, particularly in densely vegetated areas where they are hard to identify. Thus, in order to address this issue, precise inventory mapping methods are required in order to gauge landslide susceptibility in regions, as well as hazards and risk. Obstacles in the development of such mapping methods, however, are optimization techniques to employ, feature selection methods, as well as the development of model transferability. The present study seeks to utilize correlation-based feature selection and object-based approach in conjunction with LiDAR data, whereby LiDAR-DEM derived digital elevation alongside high-resolution orthophotos are employed in tandem. Next, fuzzy-based segmentation parameter optimizer was employed in order to optimize segmentation parameters. Next, support vector machine was employed in order to assess the effectiveness of the proposed method, with results illustrating the algorithm’s robustness with regards to landslide identification. The results of transferability also demonstrated the ease of use for the method, as well as its accuracy and capability to identify landslides as either shallow or deep-seated. To summarize, the study proposes that the developed methods are greatly effective in landslide detection, especially in tropical regions such as in Malaysia.
Design of accurate formulas for approximating functions in weighted Hardy spaces by discrete energy minimization
Authors: Tanaka Ken’ichiro , Sugihara Masaaki 
Published: July 2018

Abstract
We propose a simple and effective method for designing approximation formulas for weighted analytic functions. We consider spaces of such functions according to weight functions expressing the decay properties of the functions. Then we adopt the minimum worst error of the $n$-point approximation formulas in each space for characterizing the optimal sampling points for the approximation. In order to obtain approximately optimal sampling points we consider minimization of a discrete energy related to the minimum worst error. Consequently, we obtain an approximation formula and its theoretical error estimate in each space. In addition, from some numerical experiments, we observe that the formula generated by the proposed method outperforms the corresponding formula derived with sinc approximation, which is near optimal in each space.
Convergent numerical method for the Navier–Stokes–Fourier system: a stabilized scheme
Authors: Hošek Radim , She Bangwei 
Published: July 2018

AbstractWe propose a combined finite volume--finite element method for the compressible Navier–Stokes–Fourier system. A finite volume approximation is used for the density and energy equations while a finite element discretization based on the nonconforming Crouzeix–Raviart element is applied to the momentum equation. We show the stability, the consistency and finally the convergence of the scheme (up to a subsequence) toward a suitable weak solution. We are interested in the diffusive term in the form of divergence of the symmetric velocity gradient instead of the classical Laplace form appearing in the momentum equation. As a consequence, there emerges the need to add a stabilization term that substitutes the role of Korn’s inequality which does not hold in the Crouzeix–Raviart element space. The present work is a continuation of Feireisl, E., Hošek, R. & Michálek, M. (2016, A convergent numerical method for the Navier–Stokes–Fourier system. IMA J. Numer. Anal., 36, 1477--1535), where a similar scheme is studied for the case of classical Laplace diffusion. We compare the two schemes and point out that the discretization of the energy diffusion terms in the reference scheme is not compatible with the model. Finally, we provide several numerical experiments for both schemes to demonstrate the numerical convergence, positivity of the discrete density, as well as the difference between the schemes.
Strong $L^2$ convergence of time numerical schemes for the stochastic two-dimensional Navier–Stokes equations
Authors: Bessaih Hakima , Millet Annie 
Published: July 2018

Abstract
We prove that some time discretization schemes for the two-dimensional Navier–Stokes equations on the torus subject to a random perturbation converge in $L^2(\varOmega )$. This refines previous results that established the convergence only in probability of these numerical approximations. Using exponential moment estimates of the solution of the stochastic Navier–Stokes equations and convergence of a localized scheme we can prove strong convergence of fully implicit and semiimplicit temporal Euler discretizations and of a splitting scheme. The speed of the $L^2(\varOmega )$ convergence depends on the diffusion coefficient and on the viscosity parameter.