bluuebunny/crossref_metadata_2025_split huggingface dataset:
Joint distribution of a Lévy process and its running supremum
Authors: Coutin Laure , Pontier Monique , Ngom Waly 
Published: July 2018

Abstract
Let X be a jump-diffusion process and X* its running supremum. In this paper we first show that for any t > 0, the law of the pair (X*t, Xt) has a density with respect to the Lebesgue measure. This allows us to show that for any t > 0, the law of the pair formed by the random variable Xt and the running supremum X*t of X at time t can be characterized as a weak solution of a partial differential equation concerning the distribution of the pair (X*t, Xt). Then we obtain an expression of the marginal density of X*t for all t > 0.
First-passage time asymptotics over moving boundaries for random walk bridges
Authors: Sloothaak Fiona , Wachtel Vitali , Zwart Bert 
Published: July 2018

Abstract
We study the asymptotic tail behavior of the first-passage time over a moving boundary for a random walk conditioned to return to zero, where the increments of the random walk have finite variance. Typically, the asymptotic tail behavior may be described through a regularly varying function with exponent -½, where the impact of the boundary is captured by the slowly varying function. Yet, the moving boundary may have a stronger effect when the tail is considered at a time close to the return point of the random walk bridge, leading to a possible phase transition depending on the order of the distance between zero and the moving boundary.
Epigenetics and bone diseases
Authors: Huang Tu , Peng Xiu , Li Zhenxia , Zhou Quan , Huang Shishu , Wang Yuting , Li Juan , Song Youqiang 
Published: July 2018

AbstractOwing to the development of new technologies, the epigenome, a second dimensional method for genome analysis has emerged. Epigenetic mechanisms, including DNA methylation, histone modifications and noncoding RNAs, regulate gene expression without changing the genetic sequence. These epigenetic mechanisms normally modulate gene expression, trans-generational effects and inherited expression states in various biological processes. Abnormal epigenetic patterns typically cause pathological conditions, including cancers, age-related diseases, and specific cartilage and bone diseases. Facing the rapidly developing epigenetic field, we reviewed epigenetic mechanisms and their involvement with the skeletal system and their role in skeletal development, homeostasis and degeneration. Finally, we discuss the prospects for the future of epigenetics.
Classification of sugarcane varieties using visible/near infrared spectral reflectance of stalks and multivariate methods
Authors: Steidle Neto A. J. , Lopes D. C. , Toledo J. V. , Zolnier S. , Silva T. G. F. 
Published: July 2018

AbstractThe use of fast and non-destructive techniques for identifying sugarcane varieties enables the development of automatic sorting systems, contributing towards improving pre-processing steps in the alcohol and sugar industries. In this context, principal component analysis (PCA), factorial discriminant analysis (FDA), stepwise forward discriminant analysis (SFDA) and partial least-squares discriminant analysis (PLS-DA) were used to classify four Brazilian sugarcane varieties based on visible/near infrared (Vis/NIR) spectral reflectance measurements (450–1000 nm range) of stalks. All wavelengths contributed towards discriminating the sugarcane varieties, but the 600–750 nm range was most relevant. When evaluating PCA results considering the four sugarcane varieties, two of them overlapped and it was only possible to use classifiers of three varieties. Factorial discriminant analysis, PLS-DA and SFDA reached correct classifications of 0.81, 0.82 and 0.74, respectively, when considering the external validation data and the four sugarcane varieties evaluated. Results showed that Vis/NIR spectroscopy combined with discriminating methods is a promising tool for non-destructive and fast sugarcane variety classification, which can be used in the agro-food industry or directly in the field.
Exploring shared genetic bases and causal relationships of schizophrenia and bipolar disorder with 28 cardiovascular and metabolic traits
Authors: So Hon-Cheong , Chau Kwan-Long , Ao Fu-Kiu , Mo Cheuk-Hei , Sham Pak-Chung 
Published: July 2018

AbstractBackgroundCardiovascular diseases represent a major health issue in patients with schizophrenia (SCZ) and bipolar disorder (BD), but the exact nature of cardiometabolic (CM) abnormalities involved and the underlying mechanisms remain unclear. Psychiatric medications are known risk factors, but it is unclear whether there is a connection between the disorders (SCZ/BD) themselves and CM abnormalities.MethodsUsing polygenic risk scores and linkage disequilibrium score regression, we investigated the shared genetic bases of SCZ and BD with 28 CM traits. We performed Mendelian randomization (MR) to elucidate causal relationships between the two groups of disorders. The analysis was based on large-scale meta-analyses of genome-wide association studies. We also identified the potential shared genetic variants and inferred the pathways involved.ResultsWe found tentative polygenic associations of SCZ with glucose metabolism abnormalities, adverse adipokine profiles, increased waist-to-hip ratio and visceral adiposity (false discovery rate or FDR<0.05). However, there was an inverse association with body mass index. For BD, we observed several polygenic associations with favorable CM profiles at FDR<0.05. MR analysis showed that SCZ may be causally linked to raised triglyceride and that lower fasting glucose may be linked to BD. We also identified numerous single nucleotide polymorphisms and pathways shared between SCZ/BD with CM traits, some of which are related to inflammation or the immune system.ConclusionsOur findings suggest that SCZ patients may be genetically predisposed to several CM abnormalities independent of medication side effects. On the other hand, CM abnormalities in BD may be more likely to be secondary. However, the findings require further validation.
The long-term effect of typhoons on vascular epiphytes in Taiwan
Authors: Hsu Rebecca C.-C. , Wolf Jan H.D. , Tsai Jer-Min , Lin Yi-Chin 
Published: July 2018

Abstract:We used all 167 typhoon warnings issued by the Taiwanese Central Weather Bureau from 1958–2006 to assess the long-term effect of cyclone disturbance on vascular epiphytes. Tracks and eyes of past typhoons were plotted as circles with radii of Beaufort scale 7 and 10, and the frequency of each cohort in 1-km2 grid cells was calculated. The presence of vascular epiphytes in the same grid cells was predicted using species distribution models (SDMs). First, we used herbarium specimens and other sources to compile a comprehensive georeferenced vascular epiphyte database that contained 39084 records in 331 species. Next, we assigned each epiphyte record to a cell in the same 1-km2 grid as above. Finally, we used SDMs (MaXent), based on 30 environmental variables except typhoon frequency, to predict the potential presence of each species in the grid cells. For our analysis we only considered cells east of the central mountain ridge where typhoons hit with full force. After elimination of rare species and species that could not be validated in the SDMs, we were left with 156 epiphyte species in 10725 1-km2 cells. The number of projected species in the cells was 36.5 on average, varying between two and 82 species. Correlation analyses showed that, over time, typhoons led to a decrease in epiphyte richness at Beaufort scale 7 and 10 (Pearson's r = −0.07 and −0.08 respectively). Ferns, orchids, hemiepiphytes and dicotyledons generally showed the same pattern, except hemiepiphytes that showed a positive correlation at B7 (Pearson's r = 0.15). A partial canonical correspondence ordination analysis showed that, independent of temperature- and rainfall-related variables, Beaufort scale 7 and 10 typhoons also had significant influence on the species composition of the vascular epiphyte communities in the landscape. We recommend in situ monitoring of epiphytes over a long period to corroborate the suggestion from this indirect study that typhoons have a long-term effect on the distribution of epiphytes in Taiwan.
The transforming city in nineteenth-century literary journalism: Ramón de Mesonero Romanos’ ‘Madrid scenes’ and Charles Dickens’ ‘Street sketches’
Authors: SCHWAB CHRISTIANE 
Published: July 2018

ABSTRACT:Nineteenth-century urbanization and industrialization in western Europe have clearly contributed to the formation of societal knowledge and self-reflexive cultural iconographies. Especially from the 1820s onwards, one major context for discussing the social and cultural diversity of the city and concomitant socio-political tensions was the emerging market of journals and magazines. Based upon the writings of two exemplary authors, this article investigates with which techniques and metaphors nineteenth-century journalistic sketches depicted urban sociability and conditions. Furthermore, it reflects on how not only the ever more differentiating urban environments but also the proximity of different networks and institutions of knowledge encouraged the refinement of social observation and thought. Exploring a neglected genre of social knowledge production, the article proposes new perspectives for urban history and aims at stimulating a critical review of contemporary research practices in all branches of the social sciences.
Mechanism of Etching of Al-4.5Mg-1.0Mn Alloy
Authors: Gabbardo Aline D. , Wang Xi , Huggins Angeire , Frankel G. S. 
Published: July 2018

Abstract5xxx series aluminum alloys, as Al-4.5Mg-1.0Mn (AA5083), are strengthened by Mg solid solution and work hardening. A drawback of this alloy is the fact thatβphase, Al3Mg2, can precipitate on grain boundaries causing sensitization and intergranular corrosion, which is detrimental to the integrity of the structure. Metallography is an important technique to study the grain structure and highly sought for intergranular corrosion evaluation; however, revealing the grains of completely un-sensitized AA5083 is challenging. This paper introduces a new procedure to etch AA5083 samples that were solutionized at 450°C for 1.5 h. The new procedure is a two-step etching method, including a phosphoric acid pre-etching step and a Weck’s reagent coloring step. Solutionized, lightly sensitized, and as-received AA5083 were evaluated, and the grains were observed using optical microscopy. The microetching mechanism was further studied by optical profilometry, atomic force microscopy, scanning electron microscopy, and energy dispersive spectrometry. The phosphoric acid created a surface profile determined by the grain orientations and its reactivity, and the Weck’s reagent was then able to color grains by preferential MnO2formation over some pre-etched grains. Moreover, the final polishing with colloidal silica was essential to reach a high contrast image.
Effects of Confinement on Reaction‐Induced Fracturing During Hydration of Periclase
Authors: Zheng Xiaojiao , Cordonnier Benoît , Zhu Wenlu , Renard François , Jamtveit Bjørn 
Published: July 2018

AbstractHydration of a nominally dry rock can cause expansion of the solid volume, resulting in reaction‐induced fracturing and an associated increase in the porosity and permeability of the rock. We study the effect of confinement on the coupling between stress generation, reaction‐induced fracturing, and porosity evolution during the hydration of periclase (MgO) into brucite (Mg(OH)2). Samples of a microporous MgO ceramic were hydrated at 170–210 °C, 5–80 MPa confining pressure, 6–95 MPa differential stress, and 5–75 MPa pore fluid pressure in a purpose‐designed triaxial load cell. Hydration‐induced changes were recorded in situ by X‐ray microtomographic imaging at 5‐min intervals. Below 30 MPa effective mean stress, the fraction of periclase replaced by brucite is a sigmoidal function of time. After a slow start, the replacement rate picks up with concomitant intense fracturing. The porosity increase resulting from the reaction‐induced fractures is transient (pulse‐like). Following the porosity pulse the rate of replacement declines until the replacement is almost complete. Above 30 MPa, the reaction rate is slow, porosity decreases monotonically without any observable fracturing during the time of the experiment. At these stress conditions, the lack of fracturing cannot be limited by the thermodynamic affinity of the reaction. A possible interpretation is that the stress generated by the reaction may overcome the disjoining pressure at the grain‐grain interface, expelling the water film trapped there and thereby dramatically reducing the reaction rate.
Southwest Pacific Absolute Plate Kinematic Reconstruction Reveals Major Cenozoic Tonga‐Kermadec Slab Dragging
Authors: van de Lagemaat Suzanna H. A. , van Hinsbergen Douwe J. J. , Boschman Lydian M. , Kamp Peter J. J. , Spakman Wim 
Published: July 2018

AbstractTectonic plates subducting at trenches having strikes oblique to the absolute subducting plate motion undergo trench‐parallel slab motion through the mantle, recently defined as a form of “slab dragging.” We investigate here long‐term slab‐dragging components of the Tonga‐Kermadec subduction system driven by absolute Pacific plate motion. To this end we develop a kinematic restoration of Tonga‐Kermadec Trench motion placed in a mantle reference frame and compare it to tomographically imaged slabs in the mantle. Estimating Tonga‐Kermadec subduction initiation is challenging because another (New Caledonia) subduction zone existed during the Paleogene between the Australia and Pacific plates. We test partitioning of plate convergence across the Paleogene New Caledonia and Tonga‐Kermadec subduction zones against resulting mantle structure and show that most, if not all, Tonga‐Kermadec subduction occurred after ca. 30 Ma. Since then, Tonga‐Kermadec subduction has accommodated 1,700 to 3,500 km of subduction along the southern and northern ends of the trench, respectively. When placed in a mantle reference frame, the predominantly westward directed subduction evolved while the Tonga‐Kermadec Trench underwent ~1,200 km of northward absolute motion. We infer that the entire Tonga‐Kermadec slab was laterally transported through the mantle over 1,200 km. Such slab dragging by the Pacific plate may explain observed deep‐slab deformation and may also have significant effects on surface tectonics, both resulting from the resistance to slab dragging by the viscous mantle.
Influence of Bed‐Load Transport on Flow Resistance of Step‐Pool Channels
Authors: Hohermuth B. , Weitbrecht V. 
Published: July 2018

AbstractThis study investigates the influence of bed‐load transport on flow resistance and bed stability in steep step‐pool channels. A total of 86 flume experiments was performed. Stable step‐pool sequences were formed with increasing discharge under clear‐water conditions. The addition of fine bed‐load material to the flow led to a decrease in bed roughness and an increased mobility of step‐forming clasts. Velocity measurements showed that bed‐load transport significantly decreased flow resistance and increased near‐bed velocity for the conditions investigated. A set of existing resistance equations was tested against our data, of which the hydraulic geometry relation performed best. However, none of the existing equations was able to reproduce flow resistance during active bed‐load transport. Two new resistance equations based on a hydraulic geometry approach are proposed for conditions with and without bed‐load transport. The increase in near‐bed velocity associated with bed‐load transport was identified as the main cause for the observed increase in step mobility associated with bed‐load transport. For flows with bed‐load transport, step‐forming clasts were mobilized at discharges some 10% to 30% lower than under clear‐water conditions.
Exploring the Paradox of Increased Global Health and Degraded Global Environment: How Much Borrowed Time Is Humanity Living on?
Authors: Filippelli Gabriel M. 
Published: July 2018

AbstractAmple documentation of the global environmental degradation of air, land, and water paints a grim picture for the future of humanity. And yet by all measures global human health and well‐being have been improving significantly over the past several decades, including significant improvements in middle‐ and low‐income countries as well. The causes and consequences of this apparent paradox have not received the attention that they deserve, largely because they are measured and studied by different fields of inquiry. A systems approach that focuses on the drivers behind this apparent paradox of environmental degradation and human health improvement must include a combination of social and technological developments that have improved resource use, distribution, and innovation. But in many cases, such as phosphate resources and flying insect populations, the resource bank is not inexhaustible or replaceable, and priority must be placed for research and action on those critical resources upon which planetary health relies. Particularly, providing greater support and access to the table for youth leaders may be one way to create space for this first true generation of Anthroponauts to lead with solutions to our resource problems and to help build balance back into the environment‐health equation.
Lunar Swirl Morphology Constrains the Geometry, Magnetization, and Origins of Lunar Magnetic Anomalies
Authors: Hemingway Douglas J. , Tikoo Sonia M. 
Published: July 2018

AbstractLunar swirls are collections of finely structured bright and dark surface markings, alternating over length scales of typically 1–5 km. If swirls are the result of plasma interactions with crustal magnetic anomalies or electrostatic or magnetic sorting of fine materials, the magnetic field orientation must vary over similar length scales. This requires that the associated source bodies be both shallow and narrow in horizontal extent. The correspondingly restricted volume of the source bodies in turn implies strong rock magnetization. Here we show that if ∼300‐nT surface fields are necessary to produce observable swirl markings, the required rock magnetization must be >0.5 A/m, even for very shallow sources and likely closer to ∼2 A/m or more. This strong source rock magnetization, together with the geometric constraints that favor magmatic structures such as dikes or lava tubes, requires a mechanism to enhance the magnetic carrying capacity of the rocks. We propose that heating associated with magmatic activity could thermochemically alter host rocks and impart them with magnetizations an order of magnitude stronger than is typical of lunar mare basalts. Our results both place constraints on the geometry and magnetization of the source bodies and provide clues about the possible origins of the Moon's crustal magnetic anomalies.
Predictable Oxygen Isotope Exchange Between Plant Lipids and Environmental Water: Implications for Ecosystem Water Balance Reconstruction
Authors: Maxwell Toby M. , Silva Lucas C. R. , Horwath William R. 
Published: July 2018

AbstractIn this study, we present the first evidence for predictable exchange of oxygen isotopes between water and lipid compounds. Using laboratory incubations with aliphatic alcohols, hexadecanol and eicosanol, and bulk soil lipid extracts in isotopically enriched water for 160 days, we determined the magnitude and direction of exchange rates for bulk and compound‐specific lipid extracts. Our data show that δ18O ratios of long‐chain aliphatic lipids that persist in hydrophobic portions of soil organic matter integrate the signature of plant water δ18O values, which can be used to reconstruct hydrologic shifts in terrestrial systems. For bulk lipid extracts, equilibrium was reached, indicating that 22% of its oxygen content is exchangeable with a half‐life of 0.13 years. Incubations with the same bulk lipid extracts in contact with iron oxyhydroxide minerals showed no difference in exchange rates, although the exchangeable fraction decreases to 19% of the total. This result suggests that mineral surfaces can inhibit oxygen exchange for some oxygen‐containing functional groups. In contrast, pure compounds showed stable oxygen isotope signatures with no exchange under the same conditions. Taken together, these findings represent a significant development in the mechanistic understanding and application of oxygen isotopes in plant‐ and soil‐derived lipids, toward a path for the use of lipid extracts in reconstructions of ecosystem water balance.
Global Land Surface Modeling Including Lateral Groundwater Flow
Authors: Zeng Yujin , Xie Zhenghui , Liu Shuang , Xie Jinbo , Jia Binghao , Qin Peihua , Gao Junqiang 
Published: July 2018

AbstractThe groundwater system is an essential part of Earth's systems. However, most current land surface models (LSMs) for climate modeling do not explicitly account for the lateral groundwater flow process. In this study, schemes describing LSM‐lateral groundwater flow module coupling, model resolution conversion, and parallel simulation were designed and implemented to incorporate a lateral groundwater flow module into the Community Land Model 4.5. The depth to less permeable bedrock also was included in the large‐scale groundwater flow modeling. Model validation was performed using multiple observations from the 20‐year continuous groundwater table depth measurements at 67 stations in 10 countries, 1.6 million worldwide time‐averaged groundwater table depth measurements, previous knowledge about the locations of major aquifer systems, and inversed terrestrial water storage anomalies derived from satellite data. The simulated results show that the groundwater table pattern is a combined reflection of climatic and topographic factors across a range of spatial scales. Lateral groundwater flow significantly modified the equilibrium water table patterns in North Africa, the Arabian Peninsula, central Asia, and southern Australia, deepening the water tables by more than 6 m. The trend of deepening groundwater tables observed between 1970 and 2010, which was found to be 0.025 to 0.125 m/decade, was exacerbated by the lateral flow; however, the seasonal variability of the groundwater table depth was reduced by the buffering effect of the lateral flow.