bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating ETAS: The effects of truncation, missing data, and model assumptions
Authors: Seif Stefanie , Mignan Arnaud , Zechar Jeremy Douglas , Werner Maximilian Jonas , Wiemer Stefan 
Published: December 2016

AbstractThe Epidemic‐Type Aftershock Sequence (ETAS) model is widely used to describe the occurrence of earthquakes in space and time, but there has been little discussion dedicated to the limits of, and influences on, its estimation. Among the possible influences we emphasize in this article the effect of the cutoff magnitude,Mcut, above which parameters are estimated; the finite length of earthquake catalogs; and missing data (e.g., during lively aftershock sequences). We analyze catalogs from Southern California and Italy and find that some parameters vary as a function ofMcutdue to changing sample size (which affects, e.g., Omori'scconstant) or an intrinsic dependence onMcut(asMcutincreases, absolute productivity and background rate decrease). We also explore the influence of another form of truncation—the finite catalog length—that can bias estimators of the branching ratio. Being also a function of Omori'spvalue, the true branching ratio is underestimated by 45% to 5% for 1.05 < p < 1.2. Finite sample size affects the variation of the branching ratio estimates. Moreover, we investigate the effect of missing aftershocks and find that the ETAS productivity parameters (αandK0) and the Omori'scandpvalues are significantly changed forMcut < 3.5. We further find that conventional estimation errors for these parameters, inferred from simulations that do not account for aftershock incompleteness, are underestimated by, on average, a factor of 8.
Seismic swarms and diffuse fracturing within Triassic evaporites fed by deep degassing along the low‐angle Alto Tiberina normal fault (central Apennines, Italy)
Authors: Piana Agostinetti Nicola , Giacomuzzi Genny , Chiarabba Claudio 
Published: December 2016

AbstractWe present high‐resolution elastic models and relocated seismicity of a very active segment of the Apennines normal faulting system, computed via transdimensional local earthquake tomography (trans‐D LET). Trans‐D LET, a fully nonlinear approach to seismic tomography, robustly constrains high‐velocity anomalies and inversions of P wave velocity, i.e., decreases of VP with depth, without introducing bias due to, e.g., a starting model, and giving the possibility to investigate the relation between fault structure, seismicity, and fluids. Changes in seismicity rate and recurring seismic swarms are frequent in the Apennines extensional belt. Deep fluids, upwelling from the delaminating continental lithosphere, are thought to be responsible for seismicity clustering in the upper crust and lubrication of normal faults during swarms and large earthquakes. We focus on the tectonic role played by the Alto Tiberina low‐angle normal fault (ATF), finding displacements across the fault consistent with long‐term accommodation of deformation. Our results show that recent seismic swarms affecting the area occur within a 3 km thick, high VP/VS, densely cracked, and overpressurized evaporitic layer, composed of dolostones and anhydrites. A persistent low VP, low VP/VS volume, present on top of and along the ATF low‐angle detachment, traces the location of mantle‐derived CO2, the upward flux of which contributes to cracking within the evaporitic layer.
A seismological overview of the induced earthquakes in the Duvernay play near Fox Creek, Alberta
Authors: Schultz Ryan , Wang Ruijia , Gu Yu Jeffrey , Haug Kristine , Atkinson Gail 
Published: December 2016

AbstractThis paper summarizes the current state of understanding regarding the induced seismicity in connection with hydraulic fracturing operations targeting the Duvernay Formation in central Alberta, near the town of Fox Creek. We demonstrate that earthquakes in this region cluster into distinct sequences in time, space, and focal mechanism using (i) cross‐correlation detection methods to delineate transient temporal relationships, (ii) double‐difference relocations to confirm spatial clustering, and (iii) moment tensor solutions to assess fault motion consistency. The spatiotemporal clustering of the earthquake sequences is strongly related to the nearby hydraulic fracturing operations. In addition, we identify a preference for strike‐slip motions on subvertical faults with an approximate 45° P axis orientation, consistent with expectation from the ambient stress field. The hypocentral geometries for two of the largest‐magnitude (M ~4) sequences that are robustly constrained by local array data provide compelling evidence for planar features starting at Duvernay Formation depths and extending into the shallow Precambrian basement. We interpret these lineaments as subvertical faults orientated approximately north‐south, consistent with the regional moment tensor solutions. Finally, we conclude that the sequences were triggered by pore pressure increases in response to hydraulic fracturing stimulations along previously existing faults.
Canopy effects on snow sublimation from a central Arizona Basin
Authors: Svoma Bohumil M. 
Published: December 2016

AbstractGuided by 30 m terrain and forest cover data, snow sublimation from the Salt River basin in the Southwest U.S. is simulated for years 2008 (wet year) and 2007 (dry year). Downscaled meteorological input correlates well (r~0.80) with independent observations at AmeriFlux sites. Additionally, model correlation and bias with eddy‐covariance vapor flux observations is comparable to previous localized modeling efforts. Upon a 30% reduction in effective leaf area index, canopy sublimation decreases by 1.29 mm (27.0%) and 1.05 mm (23.0%) at the basin scale for the 2008 and 2007 simulations, respectively. Ground sublimation decreases 0.72 mm (4.75%) in 2008 and only 0.17 mm (1.5%) in 2007. Canopy snow‐holding capacity and frequent unloading events at lower elevations limit the variability in canopy sublimation from wet year to dry year at the basin scale. The greater decrease in snowpack sublimation in the wet year is partly due to decreased longwave radiation from the canopy reduction over a more extensive snowpack than the dry year. This decrease overcomes the increased solar radiation and wind speed during winter. A second factor is that a greater extent of the snowpack persisted into spring in 2008 than 2007, and the large increase in shortwave flux upon canopy reduction increases melt rates, reducing duration. Only in heavily forested high elevations (>2900 m above sea level) in 2008 does the snowpack persist long enough into spring to result in increased ground sublimation upon canopy reduction. As forest cover change can occur rapidly, these results are critical from water resource and ecosystem function perspectives.
Winter soil respiration in a humid temperate forest: The roles of moisture, temperature, and snowpack
Authors: Contosta Alexandra R. , Burakowski Elizabeth A. , Varner Ruth K. , Frey Serita D. 
Published: December 2016

AbstractWinter soil respiration at midlatitudes can comprise a substantial portion of annual ecosystem carbon loss. However, winter soil carbon dynamics in these areas, which are often characterized by shallow snow cover, are poorly understood due to infrequent sampling at the soil surface. Our objectives were to continuously measure winter CO2 flux from soils and the overlying snowpack while also monitoring drivers of winter soil respiration in a humid temperate forest. We show that the relative roles of soil temperature and moisture in driving winter CO2 flux differed within a single soil‐to‐snow profile. Surface soil temperatures had a strong, positive influence on CO2 flux from the snowpack, while soil moisture exerted a negative control on soil CO2 flux within the soil profile. Rapid fluctuations in snow depth throughout the winter likely created the dynamic soil temperature and moisture conditions that drove divergent patterns in soil respiration at different depths. Such dynamic conditions differ from many previous studies of winter soil microclimate and respiration, where soil temperature and moisture are relatively stable until snowmelt. The differential response of soil respiration to temperature and moisture across depths was also a unique finding as previous work has not simultaneously quantified CO2 flux from soils and the snowpack. The complex interplay we observed among snow depth, soil temperature, soil moisture, and CO2 flux suggests that winter soil respiration in areas with shallow seasonal snow cover is more variable than previously understood and may fluctuate considerably in the future given winter climate change.
High terrestrial carbon load via groundwater to a boreal lake dominated by surface water inflow
Authors: Einarsdottir Karolina , Wallin Marcus B. , Sobek Sebastian 
Published: December 2016

AbstractThe input of dissolved organic and inorganic carbon (DOC and DIC) via direct groundwater seepage to boreal lakes is often assumed to be small in noncarbonaceous areas. However, measurements are rare. We estimated the terrestrial load of DOC, DIC, and methane (CH4) to a small boreal lake for the open water period, on the basis of measured concentrations of carbon species in near‐shore groundwater wells and inlet streams, and measured area‐specific discharge. The subcatchment directly draining into the lake via groundwater seepage contributed 18% to the total water input during the open water season. Compared to stream and lake water, near‐shore groundwater concentrations of DOC were slightly elevated, and groundwater DIC and CH4 concentrations were highly elevated. Consequently, direct groundwater seepage contributed 27% to the total DOC load, 64% to the total DIC load, and 96% to the total CH4 load from the catchment to the lake. Groundwater DIC import corresponded only to 5–8% of lake carbon dioxide (CO2) emission. In incubation experiments, we observed higher photochemical DOC loss rates in stream and groundwater samples (18–55% DOC loss upon 72 h UV‐A exposure) than in lake water (15% DOC loss) and detected significant DOC flocculation in groundwater samples in both light and dark incubations (2–24% DOC loss). We conclude that even in regions where lake hydrology is dominated by surface water inflow via inlet streams, direct groundwater seepage can represent an important carbon source to boreal lakes, and groundwater DOC may be susceptible to in‐lake removal via degradation and flocculation.
Structural characterization of polypropylene/poly(lactic acid) bicomponent meltblown
Authors: Rungiah Selven , Ruamsuk Renukarn , Vroman Philippe , Takarada Wataru , Appert‐Collin Jean‐Christophe , Kikutani Takeshi 
Published: December 2016

ABSTRACTThe bicomponent meltblown process offers to associate two polymers in the same fiber generating fibrous media with new properties. In this study, we associate polypropylene (PP) and poly(lactic acid) (PLA), from renewable sources, polymers. The influence of primary air flow rate and the structural properties of the PP/PLA bicomponent meltblown are compared to PP and PLA monocomponent meltblown. The structural properties include fiber morphology and diameter, packing density, permeability, thermal shrinkage and crystallization. The results relate that the PP/PLA bicomponent meltblown fiber diameters are thinner than those of PLA monocomponent. Moreover, it has higher resistance to thermal shrinkage compared to PP monocomponent meltblown. The packing density and permeability are not affected by the association of PP and PLA due to low crimp effect. Two different filament formations of PP/PLA bicomponent meltblown at low and high primary air flow rate have also been observed. Lastly, this study illustrates that PP and PLA association is viable, showing the production of PP/PLA bicomponent microfiber and limited thermal shrinkage at high temperature. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44540.
In vivo metabolite identification of acotiamide in rats using ultra‐performance liquid chromatography–quadrupole/time‐of‐flight mass spectrometry
Authors: Patel Prinesh N. , Kalariya Pradipbhai D. , Thummar Mohit , Gananadhamu S. , Srinivas R. 
Published: December 2016

AbstractAcotiamide hydrochloride (ACT) is a drug used for the treatment of functional dyspepsia. Understanding which metabolites are likely to be formed in vivo is essential for interpreting pharmacology, pharmacokinetic and toxicology data. The metabolism of ACT has been investigated using a specific and sensitive liquid chromatography positive ion electrospray ionization high‐resolution tandem mass spectrometry method. In vivo samples including rat plasma, urine and feces were collected separately after dosing healthy Sprague–Dawley rats at a dose of 20 mg kg −1 ACT at different time points up to 24 h. The metabolites were enriched by optimized sample preparation involving protein precipitation using acetonitrile followed by solid‐phase extraction. The mass defect filter technique was used for better detection of both predicted and unexpected drug metabolites with the majority of interference ions removed. The structural elucidation of the metabolites was performed by comparing their [M + H]+ ions and their product ions with those of the parent drug. As a result, a total of seven hitherto unknown metabolites were characterized from the biosamples. The only phase I metabolite detected was N‐despropyl acotiamide, whereas six phase II glucuronide conjugate metabolites were identified.
Five New C19‐Diterpenoid Alkaloids from Delphinium tianshanicum W.T.Wang
Authors: Zhang Ji‐Fa , Shan Lian‐Hai , Gao Feng , Huang Shuai , Zhou Xian‐Li 
Published: December 2016

Five new diterpenoid alkaloids, tianshanitines A‐E (1 – 5), along with ten known compounds (6 – 15), were isolated from the EtOH extracts of the whole plant of Delphinium tianshanicum W.T.Wang. Their structures were determined based on extensive spectroscopic analyses, including 1D‐ and 2D‐NMR, HR‐ESI‐MS, and the structure of tianshanitine C (3) was confirmed by X‐ray diffraction analysis. Tianshanitine A (1) is the first example of natural diterpenoid alkaloid containing a benzoyl group at C(1) position. Tianshanitine B (2) is a rare natural diterpenoid alkaloid bearing a OH group at C(16) position. Compounds 1 – 5, 6, 8, 10, 12 and 14 were evaluated for cytotoxicity against HCT116, MCF‐7 and HepG2 human cancer cell lines.
New Furanone Derivatives and Alkaloids from the Co‐Culture of Marine‐Derived Fungi Aspergillus sclerotiorum and Penicillium citrinum
Authors: Bao Jie , Wang Jie , Zhang Xiao‐Yong , Nong Xu‐Hua , Qi Shu‐Hua 
Published: December 2016

Six new compounds including two furanone derivatives sclerotiorumins A and B (1 and 2), one novel oxadiazin derivative sclerotiorumin C (3), one pyrrole derivative 1‐(4‐benzyl‐1H‐pyrrol‐3‐yl)ethanone (4), and two complexes of neoaspergillic acid aluminiumneohydroxyaspergillin (5) and ferrineohydroxyaspergillin (6) were isolated from the co‐culture of marine‐derived fungi Aspergillus sclerotiorum and Penicillium citrinum. Compound 3 was the first natural 1,2,4‐oxadiazin‐6‐one. Compound 5 showed significant and selective cytotoxicity against human histiocytic lymphoma U937 cell line (IC50 = 4.2 μm) and strong toxicity towards brine shrimp (LC50 = 6.1 μm), and oppositely increased the growth and biofilm formation of Staphylococcus aureus.
Variability of Pinus halepensis Mill. Essential Oils and Their Antioxidant Activities Depending on the Stage of Growth During Vegetative Cycle
Authors: Djerrad Zineb , Djouahri Abderrahmane , Kadik Leila 
Published: December 2016

The impact of growth stages during vegetative cycle (B0 – B5) on chemical composition and antioxidant activities of Pinus halepensis Mill. needles essential oils was investigated for the first time. GC and GC/MS analyses pointed to a quantitative variability of components; terpene hydrocarbons derivatives, represented by α‐pinene (8.5 – 12.9%), myrcene (17.5 – 21.6%), p‐cymene (7.9 – 11.9%) and (Z)‐β‐caryophyllene (17.3 – 21.2%) as major components, decreased from 88.9% at B0 growth stage to 66.9% at B5 growth stage, whereas oxygenated derivatives, represented by caryophyllene oxide (5.4 – 12.6%) and terpinen‐4‐ol (0.4 – 3.3%) as major components, increased from 7% at B0 growth stage to 28.4% at B5 growth stage. Furthermore, our findings showed that essential oil of P. halepensis needles collected at B5 growth stage possess higher antioxidant activities by four different testing systems than those collected at B0 – B4 growth stages. This highlighted variability led to conclude that we should select essential oils to be investigated carefully depending on growth stage, in order to have the highest effectiveness of essential oil in terms of biological activities for human health purposes.
An Unconventional Acid‐Labile Nucleobase Protection Concept for Guanosine Phosphoramidites in RNA Solid‐Phase Synthesis
Authors: Jud Lukas , Micura Ronald 
Published: December 2016

AbstractWe present an innovative O6‐tert‐butyl/N2‐tert‐butyloxycarbonyl protection concept for guanosine (G) phosphoramidites. This concept is advantageous for 2′‐modified G building blocks because of very efficient synthetic access when compared with existing routes that usually employ O6‐(4‐nitrophenyl)ethyl/N2‐acyl protection or that start from 2‐aminoadenosine involving enzymatic transformation into guanosine later on in the synthetic path. The new phosphoramidites are fully compatible with 2′‐O‐tBDMS or TOM phosphoramidites in standard RNA solid‐phase synthesis and deprotection, and provide excellent quality of tailored RNAs for the growing range of applications in RNA biophysics, biochemistry, and biology.
13C NMR Spectroscopy of N‐Heterocyclic Carbenes Can Selectively Probe σ Donation in Gold(I) Complexes
Authors: Marchione Demian , Izquierdo Maria A. , Bistoni Giovanni , Havenith Remco W. A. , Macchioni Alceo , Zuccaccia Daniele , Tarantelli Francesco , Belpassi Leonardo 
Published: December 2016

AbstractThe Dewar–Chatt–Duncanson (DCD) model provides a successful theoretical framework to describe the nature of the chemical bond in transition‐metal compounds and is especially useful in structural chemistry and catalysis. However, how to actually measure its constituents (substrate‐to‐metal donation and metal‐to‐substrate back‐donation) is yet uncertain. Recently, we demonstrated that the DCD components can be neatly disentangled and the π back‐donation component put in strict correlation with some experimental observables. In the present work we make a further crucial step forward, showing that, in a large set of charged and neutral N‐heterocyclic carbene complexes of gold(I), a specific component of the NMR chemical shift tensor of the carbenic carbon provides a selective measure of the σ donation. This work opens the possibility of 1) to characterize unambiguously the electronic structure of a metal fragment (LAu(I)n+/0 in this case) by actually measuring its σ‐withdrawing ability, 2) to quickly establish a comparative trend for the ligand trans effect, and 3) to achieve a more rigorous control of the ligand electronic effect, which is a key aspect for the design of new catalysts and metal complexes.
Sodium co‐limits and catalyzes macronutrients in a prairie food web
Authors: Kaspari Michael , Roeder Karl A. , Benson Brittany , Weiser Michael D. , Sanders Nathan J. 
Published: December 2016

AbstractNitrogen and phosphorus frequently limit terrestrial plant production, but have a mixed record in regulating the abundance of terrestrial invertebrates. We contrasted four ways that Na could interact with anNPfertilizer to shape the plants and invertebrates of an inland prairie. We appliedNPand Na to m2plots in a factorial design. Aboveground invertebrate abundance was independently co‐limited by NaCl andNP, but with +NPplots supporting more individuals. We suggest the disparity arises becauseNPenhanced plant height by 35% (1 SD) over controls, providing both food and habitat, whereas NaCl provides only food. Belowground invertebrates showed evidence of serial co‐limitation, where NaCl additions alone were ineffectual, but catalyzed access toNP. This suggests the increased belowground food availability inNPplots increased Na demand. Na andNPsupply rates vary with climate, land use, and with inputs like urine. The co‐limitation and catalysis of N and P by Na thus has the potential for predicting patterns of abundance and diversity across spatial scales.
Variations in the response of the dune coast of northern France to major storms as a function of available beach sediment volume
Authors: Crapoulet Adrien , Héquette Arnaud , Marin Denis , Levoy Franck , Bretel Patrice 
Published: December 2016

AbstractA series of airborne topographic LiDAR data were obtained from May 2008 to January 2014 over two coastal sites of northern France (Bay of Wissant and east of Dunkirk). These data were used with wind and tide gauge measurements to assess the impacts of storms on beaches and coastal dunes, and particularly of the series of major storms that hit western Europe during the fall and early winter of 2013. Our results show a high variability in shoreline response from one site to the other, but also within each coastal site. Coastal dune erosion and shoreline retreat occurred at both sites, particularly on the coast of the Bay of Wissant where shoreline retreat up to about 40 m was measured. However, stability or even shoreline advance were also observed despite the occurrence of an extreme water level with a return period >100 years during the storm Xaver in early December 2013. Comparison of shoreline change with variations of coastal dune and upper beach volumes revealed only weak relationships. Our results nevertheless showed that shoreline behavior seems to strongly depend on the initial sediment volume on the upper beach before the occurrence of the storms. According to our measurements, an upper beach volume of about 30 m3 m−1 between the dune toe and the mean high water level is sufficient at these sites to protect the coastal dunes from storm waves associated with high water levels with return periods >10 years. The identification of such thresholds in terms of upper beach width or sediment volume may represent valuable information for improving the management of shoreline change by providing an estimate of the minimum quantity of sand on the upper beach necessary to ensure shoreline stability in this region. Copyright © 2016 John Wiley & Sons, Ltd.
Adaptive smoothing based on Gaussian processes regression increases the sensitivity and specificity of fMRI data
Authors: Strappini Francesca , Gilboa Elad , Pitzalis Sabrina , Kay Kendrick , McAvoy Mark , Nehorai Arye , Snyder Abraham Z. 
Published: December 2016

AbstractTemporal and spatial filtering of fMRI data is often used to improve statistical power. However, conventional methods, such as smoothing with fixed‐width Gaussian filters, remove fine‐scale structure in the data, necessitating a tradeoff between sensitivity and specificity. Specifically, smoothing may increase sensitivity (reduce noise and increase statistical power) but at the cost loss of specificity in that fine‐scale structure in neural activity patterns is lost. Here, we propose an alternative smoothing method based on Gaussian processes (GP) regression for single subjects fMRI experiments. This method adapts the level of smoothing on a voxel by voxel basis according to the characteristics of the local neural activity patterns. GP‐based fMRI analysis has been heretofore impractical owing to computational demands. Here, we demonstrate a new implementation of GP that makes it possible to handle the massive data dimensionality of the typical fMRI experiment. We demonstrate how GP can be used as a drop‐in replacement to conventional preprocessing steps for temporal and spatial smoothing in a standard fMRI pipeline. We present simulated and experimental results that show the increased sensitivity and specificity compared to conventional smoothing strategies. Hum Brain Mapp 38:1438–1459, 2017. © 2016 Wiley Periodicals, Inc.