bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methane emissions from global rice fields: Magnitude, spatiotemporal patterns, and environmental controls
Authors: Zhang Bowen , Tian Hanqin , Ren Wei , Tao Bo , Lu Chaoqun , Yang Jia , Banger Kamaljit , Pan Shufen 
Published: August 2016

AbstractGiven the importance of the potential positive feedback between methane (CH4) emissions and climate change, it is critical to accurately estimate the magnitude and spatiotemporal patterns of CH4 emissions from global rice fields and better understand the underlying determinants governing the emissions. Here we used a coupled biogeochemical model in combination with satellite‐derived contemporary inundation area to quantify the magnitude and spatiotemporal variation of CH4 emissions from global rice fields and attribute the environmental controls of CH4 emissions during 1901–2010. Our study estimated that CH4 emissions from global rice fields varied from 18.3 ± 0.1 Tg CH4/yr (Avg. ±1 SD) under intermittent irrigation to 38.8 ± 1.0 Tg CH4/yr under continuous flooding in the 2000s, indicating that the magnitude of CH4 emissions from global rice fields is largely dependent on different water schemes. Over the past 110 years, our simulated results showed that global CH4 emissions from rice cultivation increased by 85%. The expansion of rice fields was the dominant factor for the increasing trends of CH4 emissions, followed by elevated CO2 concentration, and nitrogen fertilizer use. On the contrary, climate variability had reduced the cumulative CH4 emissions for most of the years over the study period. Our results imply that CH4 emissions from global rice fields could be reduced through optimizing irrigation practices. Therefore, the future magnitude of CH4 emissions from rice fields will be determined by the human demand for rice production as well as the implementation of optimized water management practices.
Interpretation of the provenance of small‐scale heterogeneity as documented in a single eruptive unit from Mt. Jefferson, Central Oregon Cascades
Authors: Ustunisik Gokce , Loewen Matthew W. , Nielsen Roger L. , Tepley Frank J. 
Published: August 2016

AbstractMt. Jefferson is a large composite volcano located in the central Oregon Cascades that has erupted a diverse compositional suite of lavas from basalt to rhyodacite (50–72 wt. % SiO2). Individual eruptive units contain multiple populations of plagioclase, and a variety of mafic textural/mineralogical components often preserved as large centimeter to millimeter‐sized enclaves. Understanding the processes active in any volcanic center requires that we document the products of those processes. In this contribution, we documented the small‐scale compositional diversity within a single eruptive unit at Mt. Jefferson, the Whitewater Creek andesite, in order to answer three questions: (1) what are the characteristics and scale of diversity in a single eruptive unit, (2) what is the provenance of the observed components, and (3) how does that observed small‐scale diversity relate to the larger‐scale diversity observed between other flows at Mt. Jefferson. Our analyses are based on major, trace element concentrations for phenocrysts, and melt inclusions from a single eruptive unit, the Whitewater Creek andesite which is one of the most heterogeneous units erupted at Mt. Jefferson. We have identified at least four distinct components present at the centimeter scale. These components, identified on the basis of their mineralogy and composition, include three mafic (two pyroxene + plagioclase; plagioclase‐hornblende, and olivine‐orthopyroxene) and one silicic component (dacitic groundmass). To understand the relationship between the observed textural components and the magma types erupted at Mt Jefferson, equilibrium liquid compositions were calculated from the phenocryst compositions. The range exhibited by those calculated liquids covers much of the entire range represented by the lavas at Mt. Jefferson. However, it is difficult to directly connect them to specific magma types observed at Mt. Jefferson. We attribute our inability to directly link the textural components to the known magma types to post mixing diffusive reequilibration during storage and transport. These results suggest that great care should be taken in interpretation of whole rock data.
Climatic evolution of the central equatorial Pacific since the Last Glacial Maximum
Authors: Seo Inah , Lee Yuri , Lee Yong Il , Yoo Chan Min , Hyeong Kiseong 
Published: August 2016

AbstractThis paper investigates paleoceanographic changes at a central equatorial Pacific site (6°40′N, 177°28′W) since the last glacial maximum using planktic foraminifera assemblages, together with the oxygen isotope (δ18O) and Mg/Ca compositions of three species (Globigerinoides sacculifer, Pulleniatina obliquiloculata, and Globorotalia tumida) that dwell in the mixed layer, upper thermocline, and lower thermocline, respectively. While the Mg/Ca‐derived temperatures of the mixed layer and lower thermocline varied within a narrow range from 18 ka onward, the upper thermocline temperature increased by as much as 3°C during the last deglaciation (18–12 ka) with a simultaneous decrease of δ18O. These changes are best explained by an enhanced mixing of the upper ocean and a reduced habitat depth separation between P. obliquiloculata and G. sacculifer during the 18–12 ka interval. The planktic foraminifera assemblage during the same period resembles modern composition at subtropical central Pacific sites that are strongly influenced by the northeasterly Trades and North Equatorial Current (NEC). We suggest that the study site, presently under the control of the Intertropical Convergence Zone (ITCZ)‐North Equatorial Countercurrent, had been influenced by the northeasterly Trades and NEC during the 18–12 ka interval. This interpretation is consistent with previous documentation of a more southerly location of the ITCZ during two Northern Hemisphere cooling events; the Heinrich Stadial 1 and the Younger Dryas, and implies that the mean annual position of the ITCZ was located south of the study site, by at least 2° of latitude.
Stability of B2‐type FeS at Earth's inner core pressures
Authors: Gavryushkin Pavel N. , Popov Zakhar I. , Litasov Konstantin D. , Belonoshko Anatoly B. , Gavryushkin Alex 
Published: August 2016

AbstractUsing density functional theory, we investigated how substituting sulfur atoms for iron atoms affects the structure and energy of the body centered cubic and hexagonal close‐packed iron phases at 350 GPa and at 0 K. We conclude that formation of random (Fe,S) solid solutions is energetically favorable in all intermediate compositions, although the random low‐symmetry substitutions cause structural distortion. The (Fe,S) solid solution is nearly as favorable as the mechanical mixture of Fe‐hcp and FeS‐B2. This finding, in combination with dynamical stability, defines the B2 structure as a strong candidate for the sulfur‐bearing phase of the Earth's inner core.
Spatiotemporal investigation of seismicity and Coulomb stress variations prior to the 2010 ML 6.4 Jiashian, Taiwan earthquake
Authors: Wen Yi‐Ying , Chen Chien‐Chih , Wu Yi‐Hsuan , Chan Chung‐Han , Wang Yu‐Ju , Yeh Yu‐Lien 
Published: August 2016

AbstractThe 2010 ML 6.4 Jiashian earthquake struck southern Taiwan and caused some damage due to the strong ground shaking. Since the epicenter is located in a relatively low background seismicity area, we want to investigate seismicity rate changes associated with the Jiashian main shock by applying the region‐time‐length and pattern informatics algorithms. Both temporal and spatial results exhibit signatures of abnormal seismicity change related to the seismic activation and quiescence prior to the 2010 Jiashian main shock. In addition, patch of abnormal seismicity changes coincides with the region with Coulomb stress change during the same period. Our study demonstrates that the epicenter area of the 2010 Jiashian earthquake experienced a long period of seismicity rate changes and stress accumulation and thus suggests that both the variations in Coulomb stress and seismicity rate play fundamental roles in the nucleation process of impending earthquakes.
Mercury's gravity, tides, and spin from MESSENGER radio science data
Authors: Verma Ashok Kumar , Margot Jean‐Luc 
Published: August 2016

AbstractWe analyze radio tracking data obtained during 1311 orbits of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft in the period March 2011 to April 2014. A least squares minimization of the residuals between observed and computed values of two‐way range and Doppler allows us to solve for a model describing Mercury's gravity, tidal response, and spin state. We use a spherical harmonic representation of the gravity field to degree and order 40 and report error bars corresponding to 10 times the formal uncertainties of the fit. Our estimate of the product of Mercury's mass and the gravitational constant, GM = (22031.87404 ± 9×10−4) km3 s−2, is in excellent agreement with published results. Our solution for the geophysically important second‐degree coefficients (
,
) confirms previous estimates to better than 0.4% and, therefore, inferences about Mercury's moment of inertia and interior structure. Our estimate of the tidal Love number k2 = 0.464 ± 0.023 indicates that Mercury's mantle may be hotter and weaker than previously thought. Our spin state solution suggests that gravity‐based estimates of Mercury's spin axis orientation are marginally consistent with previous measurements of the orientation of the crust.
Backwater number scaling of alluvial bed forms
Authors: Shaw John B. , McElroy Brandon 
Published: August 2016

AbstractThe backwater number, Bw, compares the backwater length scale to the length scale of alluvial bed forms. We derive theory to show that Bw plays an important role in determining the behavior and scaling of morphodynamic systems. When Bw ≫ 1, spatial patterns in deposition and erosion derive from flow accelerations associated with changes in flow depth, and bed evolution is akin to a kinematic wave. When Bw ≪ 1, the spatial pattern of shear stress is determined by variations in energy slope, and alluvial beds experience topographic dispersion. This theory is confirmed using a numerical model and data compiled from the literature. We present a data set of Bw for bed forms ranging from dunes to river deltas, including field and experimental measurements. For field‐scale measurements, we find that dunes have Bw > 49, braid bars exist in the range Bw = [7.1,17], meanders have a range Bw = [7.1,18], and river mouth deposition ranges over Bw = [7.4,29]. Further, alluvial morphologies that are easily recreated in the laboratory (dunes and avulsions) have overlapping field and laboratory Bw ranges. In contrast, alluvial forms that have traditionally been difficult to recreate (meanders and river mouth processes) have field Bw that are difficult to match in laboratory settings. Large experimental Froude numbers are shown to reduce experimental Bw and incite diffusional behavior. Finally, we demonstrate the utility of Bw scaling for estimating fundamental scales in sedimentary systems.
Short‐term favorable weather conditions are an important control of interannual variability in carbon and water fluxes
Authors: Zscheischler Jakob , Fatichi Simone , Wolf Sebastian , Blanken Peter D. , Bohrer Gil , Clark Kenneth , Desai Ankur R. , Hollinger David , Keenan Trevor , Novick Kimberly A. , Seneviratne Sonia I. 
Published: August 2016

AbstractEcosystem models often perform poorly in reproducing interannual variability in carbon and water fluxes, resulting in considerable uncertainty when estimating the land‐carbon sink. While many aggregated variables (growing season length, seasonal precipitation, or temperature) have been suggested as predictors for interannual variability in carbon fluxes, their explanatory power is limited and uncertainties remain as to their relative contributions. Recent results show that the annual count of hours where evapotranspiration (ET) is larger than its 95th percentile is strongly correlated with the annual variability of ET and gross primary production (GPP) in an ecosystem model. This suggests that the occurrence of favorable conditions has a strong influence on the annual carbon budget. Here we analyzed data from eight forest sites of the AmeriFlux network with at least 7 years of continuous measurements. We show that for ET and the carbon fluxes GPP, ecosystem respiration (RE), and net ecosystem production, counting the “most active hours/days” (i.e., hours/days when the flux exceeds a high percentile) correlates well with the respective annual sums, with correlation coefficients generally larger than 0.8. Phenological transitions have much weaker explanatory power. By exploiting the relationship between most active hours and interannual variability, we classify hours as most active or less active and largely explain interannual variability in ecosystem fluxes, particularly for GPP and RE. Our results suggest that a better understanding and modeling of the occurrence of large values in high‐frequency ecosystem fluxes will result in a better understanding of interannual variability of these fluxes.
Claim Number Processes
Authors: Garrido José 
Published: August 2016

AbstractRisk theory models describe the uncertainty associated with the claims recorded by an insurance company for losses incurred by its policyholders. The claims frequency and the claims severity are two important components of these models. This article centers on models for the frequency of these losses.Even if an insurance company were able to maintain the exact same portfolio of policies over time, the number of claims recorded would still vary from year to year. Such natural fluctuations are modeled through the claim number random variable.Over time, claim counts evolve according to a stochastic process: the claim number process. While other sections discuss specific claim number processes in greater detail, the general features are given here.
Morphogenesis of the middle ear ossicles and spatial relationships with the external and inner ears during the embryonic period
Authors: Ozeki‐Satoh Maimi , Ishikawa Aoi , Yamada Shigehito , Uwabe Chigako , Takakuwa Tetsuya 
Published: August 2016

ABSTRACTWe describe the three‐dimensional morphogenesis of the middle ear ossicles (MEOs) according to Carnegie stage (CS) in human embryos. Seventeen samples including 33 MEOs from CS18 to 23 were selected from the Kyoto Collection. The primordia of the MEOs and related structures were histologically observed and three‐dimensionally reconstructed from digital images. The timing of chondrogenesis was variable among structures. The stapes was recognizable as a vague condensation of the mesenchymal cells in all samples from CS18, whereas the malleus and incus were recognizable at CS19. Chondrogenesis of all MEOs was evident in all samples after CS21. The chondrocranium was recognizable in all samples by CS18, and the perichondrium border of the auricular cartilage and otic capsule was distinct in all samples at CS23. At CS19, the MEOs were positioned in the anterior to posterior direction, following the order malleus, incus, stapes, which adjusted gradually during development. The MEOs connected in all samples after CS22. The stapes was located close to the vestibular part of the inner ear, although the basal part was not differentiated into the “footplate” form, even at CS23. The handles of the malleus were close to the tubotympanic recess at CS23, but were distant from the external auditory meatus. Determining the timeline of the formation of MEOs and connection of the external and inner ears can be informative for understanding hearing loss caused by failure of this connection. These data may provide a useful standard for morphogenesis, and will contribute to distinguishing between normal and abnormal MEO development. Anat Rec, 299:1325–1337, 2016. © 2016 Wiley Periodicals, Inc.
Metabolic engineering of methanotrophs and its application to production of chemicals and biofuels from methane
Authors: Lee Ok Kyung , Hur Dong Hoon , Nguyen Diep Thi Ngoc , Lee Eun Yeol 
Published: August 2016

AbstractMethane‐assimilating bacteria, methanotrophs, can play an important role in producing various value‐added chemicals and biofuels from methane, which is considered a next‐generation carbon feedstock. The capability to engineer the metabolic pathway of methanotrophs is a key success factor for enhancing methane‐to‐product conversion efficiency. Recently, OMICS studies on several model methanotrophs have been conducted and provided strategies to engineer methanotrophs. Here, we present a review on the current progresses and future prospects of metabolic engineering of methanotrophs and its application to chemical and biofuel production from methane. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd
Effect of appendicectomy on colonic inflammation and neoplasia in experimental ulcerative colitis
Authors: Harnoy Y , Bouhnik Y , Gault N , Maggiori L , Sulpice L , Cazals-Hatem D , Boudjema K , Panis Y , Ogier-Denis E , Treton X 
Published: August 2016

Abstract

Background
Ulcerative colitis (UC) promotes cancer, and can be ameliorated by early appendicectomy for appendicitis. The aim of the study was to explore the effect of appendicectomy on colitis and colonic neoplasia in an animal model of colitis and a cohort of patients with UC.

Methods
Five-week old IL10/Nox1DKO mice with nascent colitis and 8-week-old IL10/Nox1DKO mice with established colitis underwent appendicectomy (for experimental appendicitis or no appendicitis) or sham laparotomy. The severity and extent of colitis was assessed by histopathological examination, and a clinical disease activity score was given. From a cohort of consecutive patients with UC who underwent colectomy, the prevalence of appendicectomy and pathological findings were collected from two institutional databases.

Results
Appendicectomy for appendicitis ameliorated experimental colitis in the mice; the effect was more pronounced in the 5-week-old animals. Appendicectomy in the no-appendicitis group was associated with an increased rate of colonic high-grade dysplasia (HGD) or cancer compared with rates in sham and appendicitis groups (13 of 20 versus 0 of 20 and 0 of 20 respectively; P &lt; 0·001). Fifteen of 232 patients who underwent colectomy for UC had previously had an appendicectomy, and nine of these had colonic cancer or HGD. Thirty (13·8 per cent) of 217 patients with the appendix in situ had colonic neoplastic lesions. Multivariable analysis showed that previous appendicectomy was associated with colorectal neoplasia (odds ratio 16·88, 95 per cent c.i. 3·32 to 112·69).

Conclusion
Appendicectomy for experimental appendicitis ameliorated colitis. The risk of colorectal neoplasia appeared to increase following appendicectomy without induced appendicitis in a mouse model of colitis, and in patients with UC who had undergone appendicectomy.
Highly Crystalline Mesoporous Silicon Spheres for Efficient Visible Photocatalytic Hydrogen Evolution
Authors: Song Hongguang , Liu Dong , Yang Jia , Wang Lei , Xu Hangxun , Xiong Yujie 
Published: August 2016

AbstractHigh‐performance and low‐cost photocatalysts from earth‐abundant sources are of great importance to realize large‐scale hydrogen production. Silicon, a naturally abundant semiconductor with narrow bandgap, is an ideal photocatalyst due to its high solar energy utilization efficiency; however, its application in photocatalytic H2 production is mainly limited by energy band and surface structures. Here we report the facile synthesis of highly crystalline mesoporous silicon spheres to overcome the limitations by combining salt‐assisted aerosol synthesis with magnesiothermic reduction. The mesoporous silicon spheres possess high crystallinity, large specific surface area and optimal band structure, enabling efficient and stable photocatalytic H2 evolution (1785 μmol h−1 g−1) under visible light without precious metal cocatalysts. This work offers a scalable approach to highly crystalline mesoporous materials and provides new prospects in developing silicon photocatalysts for solar fuel production.
Design and Fabrication of a Tip‐Like ZnO Nanotube Array Structure with Condensate Microdrop Self‐Propelling Function
Authors: Luo Yuting , Gong Xiaojing , Chen Ying , Zhu Jie , Wei Jiandong , Gao Xuefeng 
Published: August 2016

AbstractHere, we present a type of tip‐like nanotube array with condensate microdrop self‐propelling (CMDSP) function. Based on the basic principle that condensate microdrops can self‐remove via coalescence‐released weak surface energy as long as interface adhesion induced energy dissipation is sufficiently low, we design tip‐like nanotubes with extremely low solid–liquid interface adhesion. To verify the feasibility of this idea, we propose a strategy of preferential etching of six corners and the interior of ZnO nanopencils to achieve tip‐like nanotubes. Our studies demonstrate that this nanostructure can be achieved by immersing ZnO nanopencils in 0.006 m HCl aqueous solution at 80 °C for 3 h. After silane modification, the resulting nanostructure shows CMDSP function. This work offers a new avenue for developing CMDSP functional films, which can find a variety of technological applications such as moisture self‐cleaning, antifrosting and enhancing heat transfer.
Considerations for assessing model averaging of regression coefficients
Authors: Banner Katharine M. , Higgs Megan D. 
Published: August 2016

AbstractModel choice is usually an inevitable source of uncertainty in model‐based statistical analyses. While the focus of model choice was traditionally on methods for choosing a single model, methods to formally account for multiple models within a single analysis are now accessible to many researchers. The specific technique of model averaging was developed to improve predictive ability by combining predictions from a set of models. However, it is now often used to average regression coefficients across multiple models with the ultimate goal of capturing a variable's overall effect. This use of model averaging implicitly assumes the same parameter exists across models so that averaging is sensible. While this assumption may initially seem tenable, regression coefficients associated with particular explanatory variables may not hold equivalent interpretations across all of the models in which they appear, making explanatory inference about covariates challenging. Accessibility to easily implementable software, concerns about being criticized for ignoring model uncertainty, and the chance to avoid having to justify choice of a final model have all led to the increasing popularity of model averaging in practice. We see a gap between the theoretical development of model averaging and its current use in practice, potentially leaving well‐intentioned researchers with unclear inferences or difficulties justifying reasons for using (or not using) model averaging. We attempt to narrow this gap by revisiting some relevant foundations of regression modeling, suggesting more explicit notation and graphical tools, and discussing how individual model results are combined to obtain a model averaged result. Our goal is to help researchers make informed decisions about model averaging and to encourage question‐focused modeling over method‐focused modeling.