bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inter‐laboratory test for oxygen and hydrogen stable isotope analyses of geothermal fluids: Assessment of reservoir fluid compositions
Authors: Verma Mahendra P. , van Geldern Robert , Barth Johannes A.C. , Monvoisin Gael , Rogers Karyne , Grassa Fausto , Carrizo Daniel , Huertas Antonio Delgado , Kretzschmar Thomas , Villanueva‐Estrada Ruth Esther , Godoy José Marcus , Mostapa Roslanzairi , Cortés Hugo Alberto Durán 
Published: July 2018

RationaleKnowledge of the accuracy and precision for oxygen (δ18O values) and hydrogen (δ2H values) stable isotope analyses of geothermal fluid samples is important to understand geothermal reservoir processes, such as partial boiling‐condensation and encroachment of cold and reinjected waters. The challenging aspects of the analytical techniques for this specific matrix include memory effects and higher scatter of delta values with increasing total dissolved solids (TDS) concentrations, deterioration of Pt‐catalysts by dissolved/gaseous H2S for hydrogen isotope equilibration measurements and isotope salt effects that offset isotope ratios determined by gas equilibration techniques.MethodsAn inter‐laboratory comparison exercise for the determination of the δ18O and δ2H values of nine geothermal fluid samples was conducted among eleven laboratories from eight countries (CeMIEGeo2017). The delta values were measured by dual inlet isotope ratio mass spectrometry (DI‐IRMS), continuous flow IRMS (CF‐IRMS) and/or laser absorption spectroscopy (LAS). Moreover, five of these laboratories analyzed an additional sample set at least one month after the analysis period of the first set. Statistical evaluation of all the results was performed to obtain the expected isotope ratios of each sample, which were then subsequently used in deep reservoir fluid composition calculations.ResultsThe overall analytical precisions of the measurements were ± 0.2‰ for δ18O values and ± 2.0‰ for δ2H values within the 95% confidence interval.ConclusionsThe measured and calculated δ18O and δ2H values of water sampled at the weir box, separator and wellhead of geothermal wells suggest the existence of hydrogen and oxygen isotope‐exchange equilibrium between the liquid and vapor phases at all sampling points in the well. Thus, both procedures for calculating the isotopic compositions of the deep geothermal reservoir fluid – using either the analytical data of the liquid phase at the weir box together with those of vapor at the separator or the analytical data of liquid and vapor phases at the separator –are equally valid.
Immersing First Graders in Poetry: A Genre Study Approach
Authors: Concannon‐Gibney Tara 
Published: July 2018

AbstractPoetry has often been described as the neglected genre despite its potential to engage and motivate students of all abilities in reading and writing. Indeed, poetry provides an excellent forum for the development of literacy skills and strategies in a meaningful context. The author describes how a teacher implemented a poetry genre study in a first‐grade classroom. The author begins by delineating the need for poetry instruction in elementary classrooms and then outlines the structure of the genre study and the variety of teaching approaches used in both reading and writing contexts. The author also shares classroom resources and examples of the literature used to illustrate how the genre study was enacted in her particular context so readers might be enabled to adapt it to suit the needs of other learners.
The Saccharomyces cerevisiae poly (A) binding protein (Pab1): Master regulator of mRNA metabolism and cell physiology
Authors: Brambilla Marco , Martani Francesca , Bertacchi Stefano , Vitangeli Ilaria , Branduardi Paola 
Published: July 2018

AbstractPab1, the major poly (A) binding protein of the yeast Saccharomyces cerevisiae, is involved in many intracellular functions associated with mRNA metabolism, such as mRNA nuclear export, deadenylation, translation initiation and termination. Pab1 consists of four RNA recognition motifs (RRM), a proline‐rich domain (P) and a carboxy‐terminal (C) domain. Due to its modular structure, Pab1 can simultaneously interact with poly (A) tails and different proteins that regulate mRNA turnover and translation. Furthermore, Pab1 also influences cell physiology under stressful conditions by affecting the formation of quinary assemblies and stress granules, as well as by stabilizing specific mRNAs to allow translation re‐initiation after stress. The main goal of this review is to correlate the structural complexity of this protein with the multiplicity of its functions.
First aspects on acetate metabolism in the yeast Dekkera bruxellensis: a few keys for improving ethanol fermentation
Authors: Teles Gilberto Henrique , da Silva Jackeline Maria , Mendonça Allyson Andrade , de Morais Junior Marcos Antonio , de Barros Pita Will 
Published: July 2018

AbstractDekkera bruxellensis is continuously changing its status in fermentation processes, ranging from a contaminant or spoiling yeast to a microorganism with potential to produce metabolites of biotechnological interest. In spite of that, several major aspects of its physiology are still poorly understood. As an acetogenic yeast, minimal oxygen concentrations are able to drive glucose assimilation to oxidative metabolism, in order to produce biomass and acetate, with consequent low yield in ethanol. In the present study, we used disulfiram to inhibit acetaldehyde dehydrogenase activity to evaluate the influence of cytosolic acetate on cell metabolism. D. bruxellensis was more tolerant to disulfiram than Saccharomyces cerevisiae and the use of different carbon sources revealed that the former yeast might be able to export acetate (or acetyl‐CoA) from mitochondria to cytoplasm. Fermentation assays showed that acetaldehyde dehydrogenase inhibition re‐oriented yeast central metabolism to increase ethanol production and decrease biomass formation. However, glucose uptake was reduced, which ultimately represents economical loss to the fermentation process. This might be the major challenge for future metabolic engineering enterprises on this yeast.
A viable QCD axion in the MeV mass range
Authors: Alves Daniele S. M. , Weiner Neal 
Published: July 2018

AbstractThe QCD axion is one of the most compelling solutions of the strong CP problem. There are major current efforts into searching for an ultralight,invisibleaxion, which is believed to be the only phenomenologically viable realization of the QCD axion.Visibleaxions with decay constants at or below the electroweak scale are believed to have been long excluded by laboratory searches. Considering the significance of the axion solution to the strong CP problem, we revisit experimental constraints on QCD axions in the$$ \mathcal{O} $$O(10 MeV) mass window. In particular, we find a variant axion model that remains compatible with existing constraints. This model predicts new states at the GeV scale coupled hadronically, and a variety of low-energy axion signatures, such as rare meson decays, nuclear de-excitations via axion emission, and production ine+e−annihilation and fixed target experiments. This reopens the possibility of solving the strong CP problem at the GeV scale.
Exactly solvable gravitating perfect fluid solitons in (2 + 1) dimensions
Authors: Adam C. , Romanczukiewicz T. , Wachla M. , Wereszczynski A. 
Published: July 2018

Abstract

The Bogomolnyi-Prasad-Sommerfield (BPS) baby Skyrme model coupled to gravity is considered. We show that in an asymptotically flat space-time the model still possesses the BPS property, i.e., admits a BPS reduction to first order Bogomolnyi equations, which guarantees that the corresponding proper energy is a linear function of the topological charge. We also find the mass-radius relation as well as the maximal mass and radius. All these results are obtained in an analytical manner, which implies the complete solvability of this selfgravitating matter system.
If a cosmological constant is added, then the BPS property is lost. In de Sitter (dS ) space-time both extremal and non-extremal solutions are found, where the former correspond to finite positive pressure solutions of the flat space-time model. For the asymptotic anti-de Sitter (AdS ) case, extremal solutions do not exist as there are no negative pressure BPS baby Skyrmions in flat space-time. Non-extremal solutions with AdS asymptotics do exist and may be constructed numerically. The impact of the negative cosmological constant on the mass-radius relation is studied. We also found two potentials for which exact multi-soliton solutions in the external AdS space can be obtained. Finally, we elaborate on the implications of these findings for certain three-dimensional models of holographic QCD.
Two-stage oxygen supply strategy based on energy metabolism analysis for improving acetic acid production by Acetobacter pasteurianus
Authors: Zheng Yu , Chang Yangang , Zhang Renkuan , Song Jia , Xu Ying , Liu Jing , Wang Min 
Published: July 2018

Abstract
Oxygen acts as the electron acceptor to oxidize ethanol by acetic acid bacteria during acetic acid fermentation. In this study, the energy release rate from ethanol and glucose under different aerate rate were compared, and the relationship between energy metabolism and acetic acid fermentation was analyzed. The results imply that proper oxygen supply can maintain the reasonable energy metabolism and cell tolerance to improve the acetic acid fermentation. Further, the transcriptions of genes that involve in the ethanol oxidation, TCA cycle, ATP synthesis and tolerance protein expression were analyzed to outline the effect of oxygen supply on cell metabolism of Acetobacter pasteurianus. Under the direction of energy metabolism framework a rational two-stage oxygen supply strategy was established to release the power consumption and substrates volatilization during acetic acid fermentation. As a result, the acetic acid production rate of 1.86 g/L/h was obtained, which were 20.78% higher than that of 0.1 vvm one-stage aerate rate. And the final acetic acid concentration and the stoichiometric yield were 88.5 g/L and 94.1%, respectively, which were 84.6 g/L and 89.5% for 0.15 vvm one-stage aerate rate.
Knowing how things might have been
Authors: Jago Mark 
Published: July 2018

AbstractI know that I could have been where you are right now and that you could have been where I am right now, but that neither of us could have been turnips or natural numbers. This knowledge of metaphysical modality stands in need of explanation. I will offer an account based on our knowledge of the natures, or essencess, of things. I will argue that essences need not be viewed as metaphysically bizarre entities; that we can conceptualise and refer to essences; and that we can gain knowledge of them. We can know about which properties are, and which properties are not, essential to a given entity. This knowledge of essence offers a route to knowledge of the ways those entities must be or could be.
Gas Absorption Center-Based Wavelength Calibration Technique in QEPAS System for SNR Improvement
Authors: Wang Zongliang , Chang Jun , Liu Qi , Tian Cunwei , Zhang Qinduan 
Published: July 2018

Abstract
A simple and effective wavelength calibration scheme is proposed in a quartz enhanced photoacoustic spectroscopy (QEPAS) system for trace gas detection. A reference gas cell is connected an InGaAs photodetector for detecting the absorption intensity peak caused by the gas to calibrate the gas absorption center using distributed feedback laser diode (DFB-LD) with sawtooth wave driver current. The gas absorption wavelength calibration and gas sensing operations are conducted at a special internal to eliminate the wavelength shift of DFB-LD caused by the ambient fluctuations. Compared with the conventional wavelength modulation spectroscopy (WMS), this method uses a lower lock-in amplifier bandwidth and averaging algorithm to improve signal noise ratio (SNR). Water vapor is chosen as a sample gas to evaluate its performance. In the experiments, the impact of sawtooth wave frequency and lock-in amplifier bandwidth on the harmonic signal is analyzed, and the wavelength-calibration technique-based system achieves a minimum detection limit (MDL) of 790 ppbv and SNR with 13.4 improvement factor compared with the conventional WMS system.
Crust structure of the northeastern Barents Sea basin area
Authors: Piskarev A.L. , Kireev A.A. , Savin V.A. , Smirnov O.E. 
Published: July 2018

Abstract
Processing of data from regional geophysical surveys completed in the northern Barents Sea has provided updates to gravity and magnetic databases, structural maps of seismic interfaces, and positions of anomaly sources, which made a basis for 3D density and magnetic models of the crust. The new geological and geophysical results placed constraints on the boundaries between basement blocks formed in different settings and on the contours of deposition zones of different ages in the northeastern Barents Sea. The estimated thicknesses of sedimentary sequences that formed within certain time spans record the deposition history of the region. There is a 20–50 km wide deep suture between two basins of Mesozoic and Paleozoic ages in the eastern part of the region, where pre-Late Triassic reflectors have no clear correlation. The suture slopes eastward at a low angle and corresponds to a paleothrust according to seismic and modeling data. In the basement model, the suture is approximated by a zone of low magnetization and density, which is common to active fault systems. The discovery of the suture has important geological and exploration implications.
The Maurynya section, West Siberia: a key section of the Jurassic–Cretaceous boundary deposits of shallow marine genesis
Authors: Dzyuba O.S. , Pestchevitskaya E.B. , Urman O.S. , Shurygin B.N. , Alifirov A.S. , Igolnikov A.E. , Kosenko I.N. 
Published: July 2018

Abstract
The Maurynya section exposed on the northwestern margin of West Siberia is one of few continuous sections of the Jurassic–Cretaceous boundary deposits in Boreal regions. In the meantime, it can be considered a reference section for the transitional Volgian–Ryazanian beds formed in shallow water environments of the West Siberian sea basin. This study is a synthesis of the new data with previous results of lithologic, paleontological, biostratigraphic, and (O, C, Sr) isotope studies of the Upper Volgian–lowermost Ryazanian of the Maurynya section. It has been established that the beginning of the Cretaceous (corresponding to the middle Late Volgian) is associated with a sharp increase in species number and diversity of cephalopods and bivalve mollusks on the northwestern margin of the West Siberian sea basin. This can be explained by an increase in its depths and their stabilization at a level which appeared optimal for the habitat of nekton, nektobenthos, and benthic fauna communities, superimposed on the general trend of warming. At the same time, the percentage of phytoplankton significantly increased, indicating the onset of transgression, which affected largely coastal landscapes and type of vegetation: The forests dominated by conifers were gradually succeeded by forests mostly composed of Ginkgoaceae.
Foraging choices balanced between resource abundance and handling concerns: how the honeybee, Apis mellifera, select the flowers of Robinia pseudoacacia
Authors: Giovanetti M. 
Published: July 2018

AbstractNectar is a main resource harvested by foraging honeybees: their ability in selecting among flowers is the key to optimize resource collection. This ability is expected to be the result of co-evolutionary traits between the plant and the pollinator visiting it; notwithstanding, novel interactions may occur between native and invasive species. Analysing foraging efforts, flexibility and individual constrains has to be taken into account. The foraging pattern of the ubiquitous honeybee on Robinia pseudoacacia, a North-American species widely naturalized in European countries, grounds a perfect case study. The plant shows papilionate flowers especially reach in nectar, but their tripping mechanism is difficult for the small/light-weight honeybee. Yet Apis mellifera is known to pay frequent and constant visits to them: in fact, one of the most appreciated unifloral honey is produced out of R. pseudoacacia. The aim of this study was to understand when and how the bees overcome physical constraints to succeed in flower visits, and to what extent this flexibility extend from the individual to the species. Data were collected in Italy, through focal observations of foraging individuals, nectar content measurements and experiments with manipulated inflorescences. Results clearly indicate that nectar content changes accordingly to the state of flowers (visited or unvisited), which also show slight changes in appearance. Foraging individuals, able to detect these differences, perform active choices preferentially selecting already-visited flowers: lower in nectar content but easier to manipulate. Even if the choice is primarily driven by handling constraints, individual experience and strength of stimuli are prompting visits also to unvisited flowers, notwithstanding a higher risk of failure in resource collection. Behavioural plasticity matching a satisfactory compromise grounds the decision that maximizes the intake of resource balanced with the effort to gain it.
Statistical Characteristics of Gravity Waves With Near‐Inertial Frequencies in the Antarctic Troposphere and Lower Stratosphere Observed by the PANSY Radar
Authors: Minamihara Y. , Sato K. , Tsutsumi M. , Sato T. 
Published: July 2018

AbstractGravity waves (GWs) have temporally and spatially small scales. Observations of GWs have been limited especially in the polar region due to its harsh environment. The purpose of this study is to elucidate the statistical characteristics of GWs in the Antarctic troposphere and lower stratosphere based on the continuous data over a year from 1 October 2015 to 30 September 2016 using the full system of the Program of the Antarctic Syowa MST/IS Radar (PANSY) radar at Syowa Station (69.0°S, 39.6°E). Such continuous observations over a long duration are unprecedented for high‐power Mesosphere‐Stratosphere‐Troposphere (MST) radars at any latitude. The frequency power spectra of horizontal wind fluctuations reveal a clear isolated maximum around the inertial frequency (f) in the lower stratosphere. A statistical analysis is performed, focusing on the GWs with near‐inertial frequencies (NIGWs) that are dominant in the lower stratosphere. According to the results of hodograph analyses, there are a considerable proportion of NIGWs propagating energy downward in the upper troposphere during all seasons, as well as in the winter stratosphere above a height of 15 km, whereas NIGWs with upward group velocities are dominant in the lower troposphere and the lowermost stratosphere. These results suggest that there are NIGW sources on the ground and around the tropopause during all seasons and in the stratosphere and/or above in winter. Plausible candidates for these sources are topography, the tropospheric jet, and the polar night jet. The statistical characteristics of NIGWs, such as horizontal phase velocity, provide powerful support for our inferences of wave sources.
Relationships Between DOC and CDOM Based on the Total Carbon‐Specific Fluorescence Intensities for River Waters Across China
Authors: Zhao Ying , Song Kaishan 
Published: July 2018

AbstractWeak correlations between chromophoric dissolved organic matter (CDOM) absorption coefficient a(440) and dissolved organic carbon (DOC) were observed due to weak absorption for river waters especially in the Qinghai‐Tibetan Plateau, and thus, it is impossible to estimate DOC concentrations by CDOM absorption across China. Therefore, it is necessary to estimate DOC concentrations through the fluorescent fraction of CDOM (i.e., FDOM). FDOM was proposed as a new method for estimation of large‐scale DOC concentrations in river waters across China. A total of 301 water samples from eight river basins across China were selected to assess FDOM by excitation‐emission matrix (EEM) fluorescence. Five fluorescent regions were obtained by EEM coupled with fluorescence regional integration (FRI) (EEM‐FRI) method. However, weak correlations between the fluorescence intensities FR(1–5), FSUM, and DOC concentrations were observed for all water samples, respectively. Therefore, the total carbon‐specific fluorescence intensities FSUM/DOC were used to establish relationships between DOC and FDOM. All 301 water samples excluding five outliers with FSUM/DOC higher than 8,000 nm/(mg/L)) were divided into four groups based on the threshold values for FSUM/DOC, and strong positive correlations between FSUM and DOC were observed in each group (R2 = 0.843, FSUM/DOC < 1,000 nm/(mg/L); R2 = 0.928, 1,000 < FSUM/DOC < 2,000 nm/(mg/L); R2 = 0.964, 2,000 < FSUM/DOC < 3,000 nm/(mg/L); and R2 = 0.953, 3,000 < FSUM/DOC < 8,000 nm/(mg/L)), respectively. This result indicated that the riverine DOC concentrations on large‐scale across China can be estimated directly by FDOM properties.
The Dewatering of the Fucino Lake Did Not Promote the M7.1 1915 Fucino Earthquake: Insights From Numerical Simulations
Authors: Cucci L. , Currenti G. , Palano M. , Tertulliani A. 
Published: July 2018

AbstractThe powerful M7.1 earthquake that devastated the Fucino Basin (Central Italy) in 1915 results to be the only (except for a M5.7 event in 1904) remarkable event to have occurred in that area, according to the 900‐year‐long record of the Italian Seismic Catalogue. Curiously, the 1915 event occurred only 38 years after the complete man‐induced dewatering of the largest lake of peninsular Italy, which formerly occupied the basin. Hence, we investigate on a possible relationship between the dewatering of the lake and the occurrence of the 1915 earthquake. We perform some numerical simulations in order to estimate the stress changes induced by the dewatering of the Fucino Lake and by the 1904 earthquake. We compute the stress changes on two different seismogenic sources selected among the ones proposed in the literature. Our main results support that (1) the dewatering process has reduced effects of the state of stress in the area before the 1915 earthquake, (2) the primary effect of the dewatering on both sources is a decrease of stresses that hampers the slip on the fault planes, and (3) the positive stress changes associated to the 1904 event would be too weak to influence the occurrence of the 1915 earthquake. We also suggest that the dewatering may have delayed by ~1.7 years the 1915 earthquake occurrence.
Three‐Dimensional Hybrid Simulation of Viscous‐Like Processes at Saturn's Magnetopause Boundary
Authors: Delamere P. A. , Burkholder B. , Ma X. 
Published: July 2018

AbstractSaturn's magnetosheath flows exhibit significant dawn/dusk asymmetry. The dawnside flows are reduced from expectation, suggesting significant momentum transport through the magnetopause boundary where the flow shear is maximized. It has been suggested that the solar wind interaction with the giant magnetospheres is, in fact, dominated by a viscous‐like interaction governed by the Kelvin‐Helmholtz instability. In three dimensions, the Kelvin‐Helmholtz instability can generate small‐scale and intermittent magnetic reconnection due, in part, to a twisted magnetic field topology. The net result is a field line threading of the magnetopause boundary and the generation of Maxwell shear stresses. Here we present three‐dimensional hybrid simulations (kinetic ions and massless fluid electrons) of conditions similar to Saturn's dawnside magnetopause boundary to quantify the viscous‐like, tangential drag. Using model‐determined momentum fluxes, we estimate the effect on dawnside sheath flows and find very good agreement with observations.