bluuebunny/crossref_metadata_2025_split huggingface dataset:
Global Three‐Dimensional Simulation of the Earth's Magnetospheric and Ionospheric Responses to Small‐Scale Magnetic Flux Ropes in the Solar Wind
Authors: Park Kyung Sun , Lee Dae‐Young , Kim Myeong Joon , Choi Cheong Rim , Kim Rok Soon , Cho Kyungsuk , Choi Kyu‐Cheol , Kim Jaehun 
Published: July 2018

AbstractThe orientation of magnetic flux ropes in the solar wind is an important component that affects interactions with the Earth's magnetosphere and ionosphere. In this study, we performed global magnetohydrodynamic (MHD) simulations on the responses of the magnetosphere and ionosphere to the impact of small‐scale magnetic flux ropes (SMFRs). We considered four types of SMFR structures according to the alignment direction of the flux rope axis in the plane perpendicular to the Sun‐Earth line. The flux rope axis of the two types is oriented in the north‐south direction, while the flux rope axis of the other two types is oriented along the dusk‐dawn direction. Accordingly, the By and Bz profiles of the SMFR types vary as the SMFR passes through the Earth. The main features of the response are as follows: (i) The magnetic reconnection on both the dayside and nightside is well organized by the specific profiles of By and Bz. (ii) One type of SMFRs where Bz turns from south to north and By remains duskward leads to plasmoid formation in the tail, distinguishing it from the other types. (iii) The temporal responses of the tail plasma flow, cross‐tail electric field, tail plasma pressure, and cross‐polar cap potential depend on the specific profiles of By and Bz, causing different response times. (iv) The evolution of ionospheric convection pattern sensitively depends on the magnetic field variation within SMFRs. (v) The peak value of cross‐polar cap potential ranges from 25 kV to >50 kV, providing energy storage suitable for substorm expansion.
Comparing Two Intervals of Exceptionally Strong Solar Rotation Recurrence of Galactic Cosmic Rays
Authors: Gil A. , Mursula K. 
Published: July 2018

AbstractTwo intervals of exceptionally strong recurrence of galactic cosmic ray (GCR) intensity at solar rotation period stand out in recent history, one in 2007–2008 and the other in 2014–2015. We use neutron monitor data from Oulu and Hermanus, solar wind (SW) data, and coronal images to study these intervals. We find that in both cases the source of solar rotation period recurrence was a coronal hole (CH), but CH structures were different. While a large, longitudinally asymmetric CH existed at high southern latitudes in 2014–2015, a low‐latitude CH caused the recurrence in 2007–2008. Spectral properties of GCR and SW parameters reflect these differences. In 2014–2015 the GCR power spectrum density was broad and peaked at a period of 28.9 days, longer than the simultaneous recurrence period of SW speed. In 2007–2008 the GCR power spectrum was narrow and peaked at 27.5 days, exactly the same as for SW speed. The effect of CHs to GCRs was somewhat different in the two cases because of opposite solar polarities in the two intervals. In 2014–2015, during positive polarity when GCRs drift inward from high latitudes, the convection of fast SW from CH reduces the inward GCR drift over a wide range of high heliolatitudes at certain heliolongitudes. In 2007–2008, during negative polarity when GCRs drift inward via the heliospheric current sheet, a low‐latitude CH depletes the GCR flux not only by convection but also by the deflecting heliospheric current sheet away from the ecliptic, whence GCR drift to higher latitudes in a limited longitude range.
Heterogeneity in Warm‐Season Land‐Atmosphere Coupling Over the U.S. Southern Great Plains
Authors: Tang Qi , Xie Shaocheng , Zhang Yunyan , Phillips Thomas J. , Santanello Joseph A. , Cook David R. , Riihimaki Laura D. , Gaustad Krista L. 
Published: July 2018

AbstractHeterogeneity in warm‐season (May–August) land‐atmosphere (LA) coupling is quantified with the long‐time, multiple‐station measurements from the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program and the Moderate Resolution Imaging Spectroradiometer satellite remote sensing at the Southern Great Plains (SGP). We examine the coupling strength at seven additional locations with the same surface type (i.e., pasture/grassland) as the ARM SGP central facility (CF). To simultaneously consider multiple factors and consistently quantify their relative contributions, we apply a multiple linear regression method to correlate the surface evaporative fraction (EF) with near‐surface soil moisture (SM) and leaf area index (LAI). The observations show moderate to weak terrestrial segment LA coupling with large heterogeneity across the ARM SGP domain in warm season. Large spatial variabilities in the contributions from SM and LAI to the EF changes are also found. The coupling heterogeneities appear to be associated with differences in land use, anthropogenic activities, rooting depth, and soil type at different stations. Therefore, the complex LA interactions at the SGP cannot be well represented by those at the CF/E13 based on the metrics applied here. Overall, the LAI exerts more influence on the EF than does the SM due to its overwhelming impacts on the latent heat flux. This study complements previous studies based on measurements only from the CF and has important implications for modeling LA coupling in weather and climate models. The multiple linear regression provides a more comprehensive measure of the integrated impacts on LA coupling from several different factors.
Characterization of the Real Part of Dry Aerosol Refractive Index Over North America From the Surface to 12 km
Authors: Aldhaif Abdulmonam M. , Stahl Connor , Braun Rachel A. , Moghaddam Mohammad A. , Shingler Taylor , Crosbie Ewan , Sawamura Patricia , Dadashazar Hossein , Ziemba Luke , Jimenez Jose L. , Campuzano‐Jost Pedro , Sorooshian Armin 
Published: July 2018

AbstractThis study reports a characterization of the real part of dry particle refractive index (n) at 532 nm based on airborne measurements over the United States, Canada, the Pacific Ocean, and the Gulf of Mexico from the 2012 Deep Convective Clouds and Chemistry (DC3) and 2013 Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaigns. Effectivenvalues are reported, with the limitations and uncertainties discussed. Eight air mass types were identified based on criteria related to gas‐phase tracer concentrations, location, and altitude. Average values ofnfor these air types ranged from 1.50 to 1.53. Values ofnfor the organic aerosol (OA) fraction (nOA) were calculated using a linear mixing rule for each air mass type, with 1.52 shown to be a good approximation for all OA. Case studies detailing vertical structure revealed thatnandnOAincreased with altitude, simultaneous with enhancements in the mass fraction of OA. Values ofnOAwere positively (negatively) correlated with the O:C (H:C) ratio in the absence of biomass burning influence; in contrast, the cumulative data set revealed a slight decrease innOAas a function of the O:C ratio. The performance of parametric (multiple linear regression) and nonparametric (Gaussian process regression) methods in predictingnbased on aerosol composition data is discussed. It is shown that even small perturbations innvalues significantly impact aerosol optical depth retrievals, radiative forcing, and optical sizing instruments, emphasizing the importance of further improving the understanding of this important aerosol property.
Where Does Titan Sand Come From: Insight From Mechanical Properties of Titan Sand Candidates
Authors: Yu Xinting , Hörst Sarah M. , He Chao , McGuiggan Patricia , Crawford Bryan 
Published: July 2018

AbstractExtensive equatorial linear dunes exist on Titan, but the origin of the sand, which appears to be organic, is unknown. We used nanoindentation to study the mechanical properties of a few Titan sand candidates, several natural sands on Earth, and common materials used in the Titan Wind Tunnel, to understand the mobility of Titan sand. We measured the elastic modulus (E), hardness (H), and fracture toughness (Kc) of these materials. Tholin's elastic modulus (10.4 ± 0.5 GPa) and hardness (0.53 ± 0.03 GPa) are both an order of magnitude smaller than silicate sand, and it is also smaller than the mechanically weak white gypsum sand. With a magnitude smaller fracture toughness (Kc = 0.036 ± 0.007 MPa·m1/2), tholin is also much more brittle than silicate sand. This indicates that Titan sand should be derived close to the equatorial regions where the current dunes are located, because tholin is too soft and brittle to be transported for long distances.
A Flexible and Efficient Radiation Scheme for the ECMWF Model
Authors: Hogan Robin J. , Bozzo Alessio 
Published: July 2018

AbstractThis paper describes a new radiation scheme ecRad for use both in the model of the European Centre for Medium‐Range Weather Forecasts (ECMWF), and off‐line for noncommercial research. Its modular structure allows the spectral resolution, the description of cloud and aerosol optical properties, and the solver, to be changed independently. The available solvers include the Monte Carlo Independent Column Approximation (McICA), Tripleclouds, and the Speedy Algorithm for Radiative Transfer through Cloud Sides (SPARTACUS), the latter which makes ECMWF the first global model capable of representing the 3‐D radiative effects of clouds. The new implementation of the operational McICA solver produces less noise in atmospheric heating rates, and is 41% faster, which can yield indirect forecast skill improvements via calling the radiation scheme more frequently. We demonstrate how longwave scattering may be implemented for clouds but not aerosols, which is only 4% more computationally costly overall than neglecting longwave scattering and yields further modest forecast improvements. It is also shown how a sequence of radiation changes in the last few years has led to a substantial reduction in stratospheric temperature biases.
Linking Paleogene Rifting and Inversion in the Northern Song Hong and Beibuwan Basins, Vietnam, With Left‐Lateral Motion on the Ailao Shan‐Red River Shear Zone
Authors: Fyhn Michael B. W. , Cuong Tong D. , Hoang Bui H. , Hovikoski Jussi , Olivarius Mette , Tuan Nguyen Q. , Tung Nguyen T. , Huyen Nguyen T. , Cuong Trinh X. , Nytoft Hans P. , Abatzis Ioannis , Nielsen Lars H. 
Published: July 2018

AbstractExtrusion tectonics forced by plate collisions shape continents not only through lateral terrain displacement and mountain building but also through massive rifting and basin development. The rift system underneath the Gulf of Tonkin, Vietnam, constitutes a world‐class example of how extrusion tectonics drives continental rifting and transtensional basin development. Rifting and the Song Hong and Beibuwan Basin evolution are compared with the development of the Ailao Shan‐Red River Shear Zone (ASRRSZ) that accommodated the extrusion of Indochina forced by the Indian‐Eurasia collision. Rifting occurred during later Eocene‐Late Oligocene time forced by ASRRSZ left‐lateral shearing. Latest Oligocene‐earliest Miocene transpression and inversion brought rifting to a halt, after which left‐lateral shearing decreased. Paleogene rift systems extended along the trail of the ASRRSZ now outlined by lower to midcrustal metamorphic core complexes. Most of these rift systems were probably inverted and removed during the latest Oligocene‐earliest Miocene, however. The metamorphic core complexes are suggested to represent the lower to midcrustal roots of these transtensional rift basins exhumed by inversion. Rift termination in the northern Gulf of Tonkin and exhumation of the metamorphic core complexes coincided with cessation of Paleogene rifting along the western South China Sea, and a common causal mechanism is speculated.
Metagenomics reveals functional synergy and novel polysaccharide utilization loci in the Castor canadensis fecal microbiome
Authors: Armstrong Zachary , Mewis Keith , Liu Feng , Morgan-Lang Connor , Scofield Melanie , Durno Evan , Chen Hong Ming , Mehr Kevin , Withers Stephen G , Hallam Steven J 
Published: July 2018

Abstract
The North American beaver (Castor canadensis) has long been considered an engineering marvel, transforming landscapes and shaping biological diversity through its dam building behavior. While the beaver possesses conspicuous morphological features uniquely adapted for the use of woody plants as construction materials and dietary staples, relatively little is known about the specialized microorganisms inhabiting the beaver gastrointestinal tract and their functional roles in determining host nutrition. Here we use a combination of shotgun metagenomics, functional screening and carbohydrate biochemistry to chart the community structure and metabolic power of the beaver fecal microbiome. We relate this information to the metabolic capacity of other wood feeding and hindgut fermenting organisms and profile the functional repertoire of glycoside hydrolase (GH) families distributed among and between population genome bins. Metagenomic screening revealed novel mechanisms of xylan oligomer degradation involving GH43 enzymes from uncharacterized subfamilies and divergent polysaccharide utilization loci, indicating the potential for synergistic biomass deconstruction. Together, these results open a functional metagenomic window on less conspicuous adaptations enabling the beaver microbiome to efficiently convert woody plants into host nutrition and point toward rational design of enhanced enzyme mixtures for biorefining process streams.
Wind turbine transformer improved design method entailing resonance blocking
Authors: Elhaminia Pedram , Vakilian Mehdi , Lehtonen Matti 
Published: July 2018

A wind turbine transformer resonance can occur due to high frequency transients at its terminal i.e.; under its energization through a length of cable. Occurrence of resonance can be addressed by a sophisticated transformer design procedure. The goal is to obtain an optimum design capable of controlling the frequency response of the winding in such a way to avoid occurrence of any resonance under transient conditions. Three insulation clearances parameters which are employed for the wind turbine transformer winding design have been investigated in design of a (800 kVA, 690/20,000 V) wind turbine transformer to determine effect of their variation on its frequency response. It is shown that the best way to control the frequency response is to adjust the distance between LV and HV windings while maintaining other clearances as short as possible; realizing limitations enforced by other insulation constraints. Multiple‐design algorithm is also investigated and found to be effective in control of the amplification factor under resonance frequency condition. Finally a 20 kV/690 V–400 kVA dry type wind turbine transformer is employed to verify the promising features of this design methodology, through comparison of the frequency responses of the real transformer against the model.
Extensive simulation of fibre non‐linearity mitigation in a CO‐OFDM‐WDM long‐haul communication system
Authors: Mhatli Sofien , Mrabet Hichem , Amari Abdelkerim 
Published: July 2018

In this study, a performance comparison of fibre non‐linearity mitigation is performed in the context of 10 and 20 Gb/s coherent optical orthogonal frequency‐division multiplexing and wavelength division multiplexing (CO‐OFDM‐WDM). The authors compare two regression methods based on the third‐order Volterra series and least mean square algorithm in terms of the bit error rate (BER) for different transmission distances and modulation formats. They also evaluate the BER as a function of the number of OFDM subcarriers for the Volterra‐based non‐linear equaliser (VNLE). In addition, by increasing the order of the VNLE from third‐order to fifth‐order series, a significant increase of performance is obtained for 100 Gb/s CO‐OFDM‐WDM system. Likewise, a comparison study of 16‐QAM 40 Gb/s CO‐OFDM system is performed as a function of Q‐factor for support vector machine, Volterra equaliser and linear equaliser, respectively.
Sulphur-bearing molecules in AGB stars
Authors: Danilovich T. , Ramstedt S. , Gobrecht D. , Decin L. , De Beck E. , Olofsson H. 
Published: July 2018

Context.Sulphur has long been known to form different molecules depending on the chemical composition of its environment. More recently, the sulphur-bearing molecules SO and H2S have been shown to behave differently in oxygen-rich asymptotic giant branch (AGB) circumstellar envelopes of different densities.Aims.By surveying a diverse sample of AGB stars for CS and SiS emission, we aim to determine in which environments these sulphur-bearing molecules most readily occur. We include sources with a range of mass-loss rates and carbon-rich, oxygen-rich, and mixed S-type chemistries. Where these molecules are detected, we aim to determine their CS and SiS abundances.Methods.We surveyed 20 AGB stars of different chemical types using the APEX telescope, and combined this with an IRAM 30 m and APEX survey of CS and SiS emission towards over 30 S-type stars. For those stars with detections, we performed radiative transfer modelling to determine abundances and abundance distributions.Results.We detect CS towards all the surveyed carbon stars, some S-type stars, and the highest mass-loss rate oxygen-rich stars, (Ṁ≥ 5 × 10−6M⊙ yr−1). SiS is detected towards the highest mass-loss rate sources of all chemical types (Ṁ≥ 8 × 10−7M⊙ yr−1). We find CS peak fractional abundances ranging from ~4 × 10−7to ~2 × 10−5for the carbon stars, from ~3 × 10−8to ~1 × 10−7for the oxygen-rich stars, and from ~1 × 10−7to ~8 × 10−6for the S-type stars. We find SiS peak fractional abundances ranging from ~9 × 10−6to ~2 × 10−5for the carbon stars, from ~5 × 10−7to ~2 × 10−6for the oxygen-rich stars, and from ~2 × 10−7to ~2 × 10−6for the S-type stars.Conclusions.Overall, we find that wind density plays an important role in determining the chemical composition of AGB circumstellar envelopes. It is seen that for oxygen-rich AGB stars both CS and SiS are detected only in the highest density circumstellar envelopes and their abundances are generally lower than for carbon-rich AGB stars by around an order of magnitude. For carbon-rich and S-type stars SiS was also only detected in the highest density circumstellar envelopes, while CS was detected consistently in all surveyed carbon stars and sporadically among the S-type stars.
Evaluation eines neuen elektronischen Handmess geräts zur Messung von β-Hydroxybutyrat bei Milchkühen
Authors: Mahrt A. , Burfeind O. , Voigtsberger R. , Müller A. , Heuwieser W. 
Published: July 2018

Zusammenfassung
Gegenstand und Ziel: Die subklinische Ketose (SCK), eine weitverbreitete Stoffwechselkrankheit frischlaktierender Milchkühe, ist definiert durch das Auftreten erhöhter Mengen zirkulierender Ketonkörper bei Fehlen klinischer Symptome. Daher beschränken sich die Möglichkeiten der Diagnostik auf den Nachweis dieser Ketonkörper in verschiedenen Körperflüssigkeiten. Ziel der Studie war die Evaluation eines neuen elektronischen mobilen Messgeräts (NovaVet) zur Messung von β-Hydroxybutyrat (BHB) im Nativblut von Milchkühen. Material und Methoden: Anhand von Blutproben von 155 laktierenden Milchkühen erfolgte ein Vergleich zwischen den mit dem Gerät ermittelten und den in einem kommerziellen Labor gemessenen BHB-Konzentrationen. Zur Auswertung wurden der Rangkorrelationskoeffizient nach Spearman bestimmt, ein Wilcoxon-Test durchgeführt und die gepaarten Messwerte nach Bland und Altman graphisch dargestellt. Ferner wurden für das Gerät spezifische BHB-Grenzwerte im Vergleich zu international anerkannten Grenzwerten zur Diagnose einer SCK mithilfe einer Receiver-Operating-Characteristic(ROC)-Analyse ermittelt und die entsprechenden Testcharakteristika bestimmt. Ergebnisse: Zwischen den vom Gerät und den im Labor gemessenen BHB-Konzentrationen bestand eine hohe Korrelation (rs = 0,87; p < 0,05). Die vom Gerät (Median 1,0 mmol/l; Interquartilsabstand [IQR] 0,7–1,3 mmol/l) und im Labor (Median 0,9 mmol/l; IQR 0,7–1,1 mmol/l) gemessenen BHB-Konzentrationen differierten (Median 0,0 mmol/l; IQR –0,1 bis 0,2 mmol/l; p < 0,05). Mit dem Gerät konnte eine SCK bei einem Grenzwert von 1,2 mmol/l BHB mit einer Sensitivität von 97% und einer Spezifität von 82% diagnostiziert werden. Als Goldstandard diente der Laborwert. Schlussfolgerung und klinische Relevanz: Das BHB-Messgerät zeigte eine gute Übereinstimmung mit dem Labor und gute Testeigenschaften. Seine geringfügige Messabweichung im Vergleich zum Labor kann unter praktischen Bedingungen vernachlässigt werden, doch muss mit einer gewissen Anzahl falsch als erkrankt diagnostizierter Tiere gerechnet werden. Das Gerät kann für die Dia gnostik der SCK beim Rind empfohlen werden.
In-clinic laboratory diagnosis of canine babesiosis (Babesia canis canis) for veterinary practitioners in Central Europe
Authors: Leschnik M. , Hooijberg E. , Tichy A. , Leidinger E. , Kirtz G. 
Published: July 2018

Summary
Objective: Haematological changes in dogs and climatic conditions favourable for the vector may assist in the quick in-house diagnosis of canine babesiosis. Material and methods: Blood samples from 358 dogs suspected to have canine babesiosis were evaluated. The diagnosis was confirmed in 113 dogs by detection of Babesia canis by microscopic examination of a stained blood smear using the concentration line technique. Results: Thrombocytopenia was present in all 113 dogs. Red blood cell count, packed cell volume and haemoglobin values were below the reference range in 62.8%, 61.1% and 46.0% of affected dogs, respectively. An increased reticulocyte count was apparent in five Babesia canis-positive dogs. Leukopenia, lymphopenia, neutropenia and monocytosis were present in 54.9%, 47.8%, 30.4% and 6.5% of the dogs, respectively. Evaluating haematological parameters by CARTanalysis revealed a predictive model (accuracy = 93.5%) for canine babesiosis, when using the leucocyte, thrombocyte, and reticulocyte count. Climatic conditions present at the most probable time of Babesia canis-infection accounted for biseasonal occurrence. Changes of climatic factors during the year influence the vector activity and in conclusion should highlight babesiosis in the ranking of differentials for veterinarians. Conclusion: The results demonstrate that a tentative diagnosis of canine babesiosis can be made based on typical haematological changes. The results recorded match well with the seasonality of the tick vector and were confirmed here by the month of sample submission.
Verabreichung von Antibiotika in Geflügelbeständen
Authors: Hafez H. M. , Böttner A. , Gangl A. , Hartmann K. , Kaske M. , Kehrenberg C. , Kietzmann M. , Klarmann D. , Klein G. , Luhofer G. , Schulz B. , Schwarz S. , Sigge C. , Waldmann K.-H. , Wallmann J. , Werckenthin C. , Richter A. ,   Arbeitsgruppe „Antibiotikaresistenz” der Deutschen Veterinärmedizinischen Gesellschaft e. V.
Published: July 2018

ZusammenfassungAus Gründen der Praktikabilität kann auf eine orale Medikation von Antibiotika zur Behandlung bakterieller Erkrankungen in Geflügelbeständen nicht verzichtet werden. Die Verabreichung von Antibiotika über das Futter oder das Trinkwasser ist jedoch mit vielen Problemen behaftet, wie Unterdosierung und Kontamination der Stalleinrichtungen, die eine Selektion von Antibiotikaresistenzen begünstigen. Auch die eingeschränkte Verfügbarkeit zugelassener Arzneimittel für verschiedene Spezies des Wirtschaftsgeflügels erschwert die Therapie bakterieller Erkrankungen in der Geflügelpraxis. Dieser Beitrag soll einen Überblick über die Probleme im Praxisalltag und mögliche Lösungsansätze geben.