bluuebunny/crossref_metadata_2025 huggingface dataset:
How individual cognitions overshadow regulations and group norms: a study of government venture capital decisions
Authors: Johansson Jeaneth , Malmström Malin , Wincent Joakim , Parida Vinit
Published: October 2019

This paper explores how government venture capitalists approve or reject financing applications. Based on longitudinal observations, complemented by interviews, documentation, and secondary data, the findings show the limited influence of the regulative and normative logics (e.g., formal guidelines and accepted behavior) on government venture capitalists’ decisions. Instead, individual decisions are observed to be largely overshadowed by cognitions and heuristics, which dominate formal regulations and socially constructed group-level norms. Although official decision communications state that regulations have been followed, the evidence suggests that the cognitive logic dominates the funding decision-making process through a set of overshadowing forces that restrict the influence of the normative and regulative logics on funding decisions. This research has implications for venture financing and highlights the importance of cognitions in shaping venture capital decisions.
Modeling the structure of recent philosophy
Authors: Noichl Maximilian
Published: October 2019

This paper presents an approach of unsupervised learning of clusters from a citation database, and applies it to a large corpus of articles in philosophy to give an account of the structure of the discipline. Following a list of journals from the PhilPapers-archive, 68,152 records were downloaded from the Reuters Web of Science-Database. Their citation data was processed using dimensionality reduction and clustering. The resulting clusters were identified, and the results are graphically represented. They suggest that the division of analytic and Continental philosophy in the considered timespan is overstated; that analytical, in contrast to Continental philosophy does not form a coherent group in recent philosophy; and that metaphors about the disciplinary structure should focus on the coherence and interconnectedness of a multitude of smaller and larger subfields.
Cerium Oxide Nanoparticles Affect Heavy Metals Uptake by Pea in a Divergent Way than Their Ionic and Bulk Counterparts
Authors: Skiba Elżbieta , Wolf Wojciech M.
Published: October 2019

The impact of cerium oxide nanoparticles, bulk cerium oxide and ionic cerium nitrate on the plant development as well as the uptake and further translocation of Cu, Mn, Zn and Fe by sugar pea (Pisum sativum L.) was investigated. Plants were cultivated in the laboratory pot experiments using the modified Hoagland solutions supplemented with cerium compounds at the 200 mg L−1 Ce level. Analysis of variance proved that cerium oxide nanoparticles significantly decreased Cu, Mn, Zn and Fe concentrations in roots and above ground parts of the pea plants. The latter ions are presumably transported via symplastic pathways and may compete with nanoparticles for similar carriers. The lowest impact on the plant growth and the metal uptake was observed under the bulk CeO2 treatment. On the contrary, strongest interactions were observed for supplementation with ionic cerium nitrate. The highly beneficial effect of cerium oxide nanoparticles on the plant growth was not supported by this study. The latter conclusion is of particular relevance when environmental impact of cerium compounds on the waste management, municipal urban low emissions and food production is to be concerned.
Fenton’s reaction-based chemical oxidation in suboptimal conditions can lead to mobilization of oil hydrocarbons but also contribute to the total removal of volatile compounds
Authors: Talvenmäki Harri , Lallukka Niina , Survo Suvi , Romantschuk Martin
Published: October 2019

Fenton’s reaction-based chemical oxidation is in principle a method that can be utilized for all organic fuel residues thus making it a potential all-purpose, multi-contaminant, in situ application for cases in which storage and distribution of different types of fuels have resulted in contamination of soil or groundwater. Since peroxide breakdown reactions are also expected to lead to a physical transport of the target compound, this secondary physical removal, or rebound concentrations related to it, is prone to be affected by the chemical properties of the target compound. Also, since soil conditions are seldom optimal for Fenton’s reaction, the balance between chemical oxidation and transport may vary. In this study, it was found that, with a high enough hydrogen peroxide concentration (5 M), methyl tert-butyl ether–spiked groundwater could be treated even under suboptimal conditions for chemical mineralization. In these cases, volatilization was not only contributing to the total removal but also leading to rebound effects similar to those associated with air sparging techniques. Likewise for diesel, temporal transport from soil to the aqueous phase was found to lead to false positives that outweighed the actual remediation effect through chemical mineralization.
Constitutive Behavior of an AA4032 Piston Alloy with Cu and Er Additions upon High-Temperature Compressive Deformation
Authors: Chankitmunkong Suwaree , Eskin Dmitry G. , Limmaneevichitr Chaowalit
Published: October 2019

Aluminum piston alloys of the AA4032 type are produced by direct-chill (DC) casting and subsequent forging; therefore, it is important to understand their thermomechanical behavior. In recent years, it was shown that additions of Cu and Er could improve mechanical properties of these alloys at room and high temperatures. In this work, we studied the constitutive behavior of AA4032-type alloys with and without Cu and Er additions. The experimental true stress–true strain curves were obtained by compression tests under various temperatures [683 K to 723 K (410 °C to 450 °C)] and strain rates (0.01 to 10 s−1) to determine constitutive parameters [strain-rate sensitivity, activation energy, and Zener–Hollomon (Z) parameter] for the hot deformation behavior of AA4032-type piston alloys with and without additions of Cu and Er. The flow stress decreased with increasing deformation temperature and decreasing strain rate. The results also showed that increasing the Cu content increased the flow stress over the applied range of deformation conditions due to solid-solution strengthening and the formation of primary Si particles, which led to an increase in the activation energy during hot deformation. Moreover, the main microstructural damage in the AA4032 alloy with 3.5 pct Cu was predominantly due to the cracking of primary Si particles. Additions of 0.4 pct Er and 3.5 pct Cu lower the activation energy of deformation, Q, as compared to the base alloy and the alloy with 3.5 pct Cu. The microstructures in the deformed specimens consisted of subgrains, recrystallized grains, and fine eutectic phases. The alloys containing Er demonstrated more polygonized grains at a low strain rate than the alloys without Er, indicating that Er hindered recrystallization development. The peak stress of the AA4032 alloy with 3.5 pct Cu alloy was higher than for the base AA4032 alloy and for the AA4032 alloy with 3.5 pct Cu and 0.4 pct Er additions, which was attributed to the prevalence of the work-hardening mechanism over the softening mechanism.
A Weighting Grade-Based Optimization Method for Determining Refill Friction Stir Spot Welding Process Parameters
Authors: Kluz Rafał , Kubit Andrzej , Trzepiecinski Tomasz , Faes Koen , Bochnowski Wojciech
Published: October 2019

The welding process used in fabricating thin-walled structures by refill friction stir spot welding (RFSSW) should be characterized by a high strength of welds and high process repeatability which is demonstrated by a small dispersion of the load capacity of the joints. The present work is designed to optimize RFSSW process parameters for 7075-T6 Alclad aluminum alloy sheets used to fabricate aircraft structures. The optimization was performed by scalarization of the objective function using the weighting grades method. The study considers the effect of process parameters, i.e., tool plunge depth, duration of welding, tool rotational speed, on the tensile/shear strength of the joints, and dispersion of the load capacity. It was found that it was possible to choose the optimal welding parameters taking into account maximization of the load capacity and minimization of the dispersion of the joint strength via a best compromise between the tool rotational speed ensuring adequate plasticization of the base material and the duration of welding ensuring that a fine-grained joint microstructure is obtained.
The Condition of Ni-Cr Alloy Surface After Abrasive Blasting with Various Parameters
Authors: Czepułkowska Weronika , Wołowiec-Korecka Emilia , Klimek Leszek
Published: October 2019

The parameters of abrasive blasting process directly affect the condition of the metal surface, changing the degree of surface roughness and wettability, depending on the size of the used particle, the pressure or type of abrasive. The aim of this study was to analyze the condition of Ni-Cr alloy surface after abrasive blasting using various process variants. The samples were blasted by Al2O3 abrasive using various particle sizes and pressures of the process. Basic and specific roughness parameters were investigated, and a surface wettability test was performed, and the percentage share of abrasive particles penetrated in the surface after abrasive blasting was also examined. The most considerable differences in the condition of the surface were observed with the change in the particle size of Al2O3. Statistical analysis confirmed the statistical significance of all these relationships.
Association between TERT promoter mutations and clinical behaviors in differentiated thyroid carcinoma: a systematic review and meta-analysis
Authors: Yang Jing , Gong Yanping , Yan Shuping , Chen Hui , Qin Siqin , Gong Rixiang
Published: October 2019

Background

The association between telomerase reverse transcriptase (TERT) promoter mutations and some clinical behaviors in thyroid cancer remains controversial and requires additional investigation. This study aimed to evaluate the association between TERT promoter mutations and clinical behaviors (including clinicopathological features and prognosis) in differentiated thyroid carcinomas (DTC).

Methods

We performed an up-to-date systematic review and current comprehensive meta-analysis. We searched three electronic databases for relevant studies. We used fixed- or random-effect models to calculate pooled estimated odds ratios (ORs) or standardized mean differences (SMDs) and corresponding 95% confidence intervals (CIs).

Results

We included 51 eligible studies incorporating 11,382 cases. Average frequencies of TERT promoter mutations in DTC, papillary (PTC), and follicular (FTC) thyroid carcinomas were 10.9%, 10.6%, and 15.1%, respectively. In DTC and PTC, TERT promoter mutations were significantly associated with sex, age, tumor size, vascular invasion, extrathyroidal extension, lymph node and distant metastases, advanced tumor, nodes, and metastasis (TNM) stage, persistence/recurrence, and disease-specific mortality. In FTC, TERT promoter mutations were significantly associated with age, distant metastases, advanced TNM stage, persistence/recurrence, and disease-specific mortality.

Conclusions

TERT promoter mutations could be considered as biomarkers assisting in risk stratification, prognostic prediction, and individualizing therapeutic options for DTC (PTC and FTC).
The Role of Approach and Avoidance Motivation and Emotion Regulation in Coping Via Health Information Seeking
Authors: Chasiotis Anita , Wedderhoff Oliver , Rosman Tom , Mayer Anne-Kathrin
Published: October 2019

When dealing with a health threat, health information seeking (HIS) is a prominent way of engagement coping. Yet, there is only limited research as to its motivational and emotion regulatory antecedents. We present a theoretical model integrating approach and avoidance motivation, emotion regulation, HIS self-efficacy, and problem and emotion coping focus as predictors of HIS. We propose that, in the context of HIS, (1) approach and avoidance motivation have a direct effect on emotion regulation ability (positive and negative, respectively), (2) approach and avoidance motivation have indirect effects on intended comprehensiveness of search via emotion regulation, HIS self-efficacy and problem coping focus, (3) avoidance motivation has a direct effect on emotion coping focus. Our model was tested by means of structural equation modeling in a sample of university students (N = 283). Model fit was good, and all three hypotheses were supported. We show that emotion regulation ability is essential to explain the effects of approach and avoidance motivation on HIS as it fosters self-efficacy and a problem coping focus. The direct effect of avoidance motivation on emotion focus may represent an alternative way of coping with a health threat for those individuals who are highly sensitive to threat-related emotions.
Plant Knowledge in the Historia Naturalis Brasiliae (1648): Retentions of Seventeenth-Century Plant Use in Brazil
Authors: Alcantara-Rodriguez Mireia , Françozo Mariana , van Andel Tinde
Published: October 2019

TheHistoria Naturalis Brasiliae(HNB, 1648) is the most complete treatise on Brazilian flora and fauna created in the seventeenth century. Scientists Marcgrave and Piso depicted hundreds of plants and described uses, vernacular names, and diseases in Dutch Brazil. We aimed to verify whether these plants are still used similarly, using herbarium vouchers and taxonomic literature to identify the species described in the HNB and reviewing historical and modern ethnobotanical literature to analyze whether the HNB documented specific plants and uses for the northeast region. We highlighted Old World species, as they indicate plant introduction before and during the trans-Atlantic slave trade and exchange of African ethnobotanical knowledge. Of the 378 species found in the HNB, 256 (68%) were useful, mostly used for healing and food in a similar way (80%) both in the seventeenth century and in modern Brazil. Only one species (Swartzia pickelii) is endemic to northeast Brazil, while the others are more widely distributed. The HNB includes one of the first reports on African crops in Brazil, such as sesame, okra, and spider plant. This study brings insights on indigenous and African plant knowledge retentions since the creation of the HNB and acknowledges its non-European contributors.
Renal Cell Carcinoma with Clear Cell Papillary Features: Perspectives of a Differential Diagnosis
Authors: Somorácz Áron , Kuthi Levente , Micsik Tamás , Jenei Alex , Hajdu Adrienn , Vrabély Brigitta , Rásó Erzsébet , Sápi Zoltán , Bajory Zoltán , Kulka Janina , Iványi Béla
Published: October 2019

Thirty-one cases of low-grade renal cell carcinoma (RCC) with clear cells and tubulopapillary/papillary architecture were analyzed retrospectively with immunohistochemical and genetic markers to gain more experience with the differential diagnosis of such cases. All samples coexpressed CK7 and CA9; the TFE3 or TFEB reactions were negative; the CD10 and the AMACR stainings were negative in 27 cases and 30 cases, respectively. The FISH assays for papillary RCC, available in 27 cases, and deletion of chromosome 3p, available in 29 cases, gave negative results. The results for 3p deletion,VHLgene mutation orVHLgene promoter region hypermethylation testing, along with the diffuse CD10-positivity in 2 cases confirmed 21 cases as clear cell papillary RCC (CCPRCC; CK7+, CA9+; no 3p loss, noVHLabnormality) and 10 cases as clear cell RCC (CCRCC; CK7+, CA9+; no 3p loss,VHLabnormality mutation/hypermethylation present). In CCPRCCs, the representative growth pattern was branching tubulo-acinar, commonly accompanied by cyst formation. The linear nuclear arrangement or cup-shaped staining of CA9 did not necessarily indicate CCPRCC, and the absence of these did not exclude the diagnosis of CCPPRC. One tumor infiltrated the renal sinus; the others exhibited pT1 stage; and metastatic outcome was not recorded. The CCRCC cases were in pT1 stage; 6 exhibited cup-shaped staining of CA9, and 1 displayed lymph node metastasis at the time of surgery. Distant metastatic disease was not observed. In summary, theVHLabnormalities distinguished the subset of CCRCC with diffuse CK7-positivity and no 3p loss from cases of CCPRCC.
The natural progression of a fistulizing gallstone resulting in massive gastrointestinal hemorrhage and Bouveret syndrome, a rare case
Authors: Hoekstra Elmer , van den Berg Maarten Willem , Veenendaal Roeland Andreas , Stuyt Rogier
Published: October 2019

Gallstones are seen very common, especially in the Western World. While most patients are asymptomatic, gallstones can cause life-threatening complications. Here, we present a rare and nearly fatal complication of gallstones, showing the natural progression of gallstone disease. With two very unusual complications of gallstones which occurred in the same patient. Massive gastrointestinal bleeding, and the Bouveret syndrome.
Deperetomys (Rodentia, Muridae) from the Oligocene of Serbia and Bosnia and Herzegovina
Authors: Marković Zoran , de Bruijn Hans , van de Weerd Andrew A. , Wessels Wilma
Published: October 2019

Two new late Oligocene species ofDeperetomys:D. calefactusandD. saltensis, are described and the affinities between the various species are discussed. The new records extend the stratigraphic range ofDeperetomysinto the Oligocene, making it the first European Miocene murid that can be traced across the “Cricetid vacuum”. A single M1 of a large early Oligocene murid that may represent the oldest record ofDeperetomysis described. The classification problems that arise as a result of the fast increase of information of the Paleogene Muridae from Asia and the Middle East are addressed and the need to recognise and define clades above the genus level is demonstrated. Our conclusion is that theDeperetomysclade contains at least three different evolutionary lineages.
Experimental study of the performances of commercial surfactants in reducing interfacial tension and wettability alteration in the process of chemical water injection into carbonate reservoirs
Authors: Najimi Siamak , Nowrouzi Iman , Khaksar Manshad Abbas , Mohammadi Amir H.
Published: October 2019

Surfactants are used in the process of chemical water injection to reduce interfacial tension of water and oil and consequently decrease the capillary pressure in the reservoir. However, other mechanisms such as altering the wettability of the reservoir rock, creating foam and forming a stable emulsion are also other mechanisms of the surfactants flooding. In this study, the effects of three commercially available surfactants, namely AN-120, NX-1510 and TR-880, in different concentrations on interfacial tension of water and oil, the wettability of the reservoir rock and, ultimately, the increase in oil recovery based on pendant drop experiments, contact angle and carbonate core flooding have been investigated. The effects of concentration, temperature, pressure and salinity on the performances of these surfactants have also been shown. The results, in addition to confirming the capability of the surfactants to reduce interfacial tension and altering the wettability to hydrophilicity, show that the TR-880 has the better ability to reduce interfacial tension than AN-120 and NX-1510, and in the alteration of wettability the smallest contact angle was obtained by dissolving 1000 ppm of surfactant NX-1510. Also, the results of interfacial tension tests confirm the better performances of these surfactants in formation salinity and high salinity. Additionally, a total of 72% recovery was achieved with a secondary saline water flooding and flooding with a 1000 ppm of TR-880 surfactant.
On controllability for a nondensely defined fractional differential equation with a deviated argument
Authors: Raheem A. , Kumar M.
Published: October 2019

This article deals with a fractional differential equation with a deviated argument defined on a nondense set. A fixed-point theorem and the concept of measure of noncompactness are used to prove the existence of a mild solution.
Furthermore, by using the compactness of associated cosine family, we proved that system is approximately controllable and obtains an optimal control which minimizes the performance index. To illustrate the abstract result, we included an example.
Northern Hemisphere Stationary Waves in a Changing Climate
Authors: Wills Robert C. J. , White Rachel H. , Levine Xavier J.
Published: October 2019

Purpose of Review

Stationary waves are planetary-scale longitudinal variations in the time-averaged atmospheric circulation. Here, we consider the projected response of Northern Hemisphere stationary waves to climate change in winter and summer. We discuss how the response varies across different metrics, identify robust responses, and review proposed mechanisms.

Recent Findings

Climate models project shifts in the prevailing wind patterns, with corresponding impacts on regional precipitation, temperature, and extreme events. Recent work has improved our understanding of the links between stationary waves and regional climate and identified robust stationary wave responses to climate change, which include an increased zonal lengthscale in winter, a poleward shift of the wintertime circulation over the Pacific, a weakening of monsoonal circulations, and an overall weakening of stationary wave circulations, particularly their divergent component and quasi-stationary disturbances.

Numerous factors influence Northern Hemisphere stationary waves, and mechanistic theories exist for only a few aspects of the stationary wave response to climate change. Idealized studies have proven useful for understanding the climate responses of particular atmospheric circulation features and should be a continued focus of future research.
A master stability function approach to cardiac alternans
Authors: Lai Yi Ming , Veasy Joshua , Coombes Stephen , Thul Rüdiger
Published: October 2019

During a single heartbeat, muscle cells in the heart contract and relax. Under healthy conditions, the behaviour of these muscle cells is almost identical from one beat to the next. However, this regular rhythm can be disturbed giving rise to a variety of cardiac arrhythmias including cardiac alternans. Here, we focus on so-called microscopic calcium alternans and show how their complex spatial patterns can be understood with the help of the master stability function. Our work makes use of the fact that cardiac muscle cells can be conceptualised as a network of networks, and that calcium alternans correspond to an instability of the synchronous network state. In particular, we demonstrate how small changes in the coupling strength between network nodes can give rise to drastically different activity patterns in the network.
How do urban mobility (geo)graph’s topological properties fill a map?
Authors: Lima Santos Leonardo Bacelar , Carvalho Luiz Max , Seron Wilson , Coelho Flávio C. , Macau Elbert E. , Quiles Marcos G. , V. Monteiro Antônio M.
Published: October 2019

Urban mobility data are important to areas ranging from traffic engineering to the analysis of outbreaks and disasters. In this paper, we study mobility data from a major Brazilian city from a geographical viewpoint using a Complex Network approach. The case study is based on intra-urban mobility data from the Metropolitan area of Rio de Janeiro (Brazil), presenting more than 480 spatial network nodes. While for the mobility flow data a log-normal distribution outperformed the power law, we also found moderate evidence for scale-free and small word effects in the flow network’s degree distribution. We employ a novel open-source GIS tool to display (geo)graph’s topological properties in maps and observe a strong traffic-topology association and also a fine adjustment for hubs location for different flow threshold networks. In the central commercial area for lower thresholds and in high population residential areas for higher thresholds. This set of results, including statistical, topological and geographical analysis may represent an important tool for policymakers and stakeholders in the urban planning area, especially by the identification of zones with few but strong links in a real data-driven mobility network.
Spreading of rodent infestations through a city
Authors: Brooks Dalton , Matta John
Published: October 2019

This paper details a network-based analysis of the spreading of rodent infestations through a city under varying conditions. Models of two very different cities, Tulsa, OK, USA and Providence, RI, USA, are created as geometric graphs using publicly available map data. The SIR epidemic model is applied with varying parameters, and the resulting infestation rates are measured. Results indicate that the density of a city, the size of the largest connected component (from the point of view of a rodent migrating to a new location), and the distance and probability of migration all play a role in determining the resulting rate of infestation. Results obtained are consistent with infestation patterns and rates reported by studies of other similarly dense city environments. For Providence a targeted attack simulation is run, which shows that carefully targeted extermination interventions could reduce infestation in the city by approximately 40%.
Radiative Influence of Horizontally Oriented Ice Crystals over Summit, Greenland
Authors: Stillwell Robert A. , Neely Ryan R. , Thayer Jeffrey P. , Walden Von P. , Shupe Matthew D. , Miller Nathaniel B.
Published: October 2019

Ice crystals commonly adopt a horizontal orientation under certain aerodynamic and electrodynamic conditions that occur in the atmosphere. While the radiative impact of horizontally oriented ice crystals (HOIC) has been theoretically studied with respect to their impact on shortwave cloud albedo, the longwave impact remains unexplored. This work analyzes the occurrence of HOIC at Summit, Greenland, from July 2015 to June 2017. Using polarization lidar and ancillary atmospheric sensors, ice crystal orientations are identified and used to interpret cloud radiative impact on the surface radiation budget. We find HOIC occur in at least 25.6% of all ice‐only column observations. We find that the shortwave impact of HOIC is to increase cloud radiative effect by approximately 22% for a given solar zenith angle. We also find that the longwave impact of HOIC compared to randomly oriented ice crystals are statistically different at the p < 0.01 significance level, increasing the surface radiative effect by approximately 8% for clouds with infrared optical depths < ~1. We suggest that the observed difference between the surface radiative effect for clouds containing randomly oriented ice crystals and HOIC may be due to enhanced scattering, but this hypothesis needs to be further explored with more detailed observations and modeling.
Disentangling Drivers of Meteorological Droughts in the European Greater Alpine Region During the Last Two Centuries
Authors: Haslinger K. , Hofstätter M. , Kroisleitner C. , Schöner W. , Laaha G. , Holawe F. , Blöschl G.
Published: October 2019

This study investigates the atmospheric drivers of severe precipitation deficits in the Greater Alpine Region during the last 210 years utilizing a daily atmospheric circulation type reconstruction. Precipitation deficit tends to be higher during periods with more frequent anticyclonic (dry) and less frequent cyclonic (wet) circulation types, as would be expected. However, circulation characteristics are not the main drivers of summer precipitation deficit. Dry soils in the warm season tend to limit precipitation, which is particularly the case for circulation types that are sensitive to a soil moisture‐precipitation feedback. This mechanism is of specific relevance in explaining the major drought decades of the 1860s and 1940s. Both episodes show large negative precipitation anomalies in spring followed by increasing frequencies of circulation types sensitive to soil moisture precipitation feedbacks. The dry springs of the 1860s were likely caused by circulation characteristics that were quite different from those of recent decades as a consequence of the large spatial extent of Arctic sea ice at the end of the Little Ice Age. On the other hand, the dry springs of the 1940s developed under a persistent positive pressure anomaly across Western and Central Europe, triggered by positive sea surface temperatures in the western subtropical Atlantic.
Different Precipitation Elasticity of Runoff for Precipitation Increase and Decrease at Watershed Scale
Authors: Tang Yin , Tang Qiuhong , Wang Zhonggen , Chiew Francis H. S. , Zhang Xuejun , Xiao Han
Published: October 2019

The precipitation elasticity of runoff, defined as the percentage change in mean annual runoff for a given percentage change in mean annual precipitation, has been widely used as a simple rule of thumb for estimating runoff sensitivity to changes in precipitation. Most applications assume the same runoff sensitivity for both an increase and a decrease in precipitation. This study examines this assumption using long historical annual precipitation and streamflow data from 353 watersheds across the United States. The results show that the assumption is acceptable in humid and subhumid regions (aridity index less than 1.0). However, in arid and semiarid regions (aridity index greater than 1.0), the sensitivity of runoff to precipitation is greater for a decrease in precipitation than for an increase in precipitation. Therefore, the use of precipitation elasticity of runoff estimated using the entire data set in semiarid and arid regions will result in an overestimation of runoff increase from precipitation increase and an underestimation of runoff decrease from a decrease in precipitation. These findings suggest that multiple precipitation elasticities of runoff may be needed to estimate nonlinear responses of streamflow to precipitation change in a changing climate, especially for persistent increase and decrease in precipitation.
Combined Effect of Tides and Varying Inland Groundwater Input on Flow and Salinity Distribution in Unconfined Coastal Aquifers
Authors: Kuan Woei Keong , Xin Pei , Jin Guangqiu , Robinson Clare E. , Gibbes Badin , Li Ling
Published: October 2019

Tides and seasonally varying inland freshwater input, with different fluctuation periods, are important factors affecting flow and salt transport in coastal unconfined aquifers. These processes affect submarine groundwater discharge (SGD) and associated chemical transport to the sea. While the individual effects of these forcings have previously been studied, here we conducted physical experiments and numerical simulations to evaluate the interactions between varying inland freshwater input and tidal oscillations. Varying inland freshwater input was shown to induce significant water exchange across the aquifer‐sea interface as the saltwater wedge shifted landward and seaward over the fluctuation cycle. Tidal oscillations led to seawater circulations through the intertidal zone that also enhanced the density‐driven circulation, resulting in a significant increase in the total SGD. The combination of the tide and varying inland freshwater input, however, decreased the SGD components driven by the separate forcings (e.g., tides and density). Tides restricted the landward and seaward movement of the saltwater wedge in response to the varying inland freshwater input in addition to reducing the time delay between the varying freshwater input signal and landward‐seaward movement in the saltwater wedge interface. This study revealed the nonlinear interaction between tidal fluctuations and varying inland freshwater input will help to improve our understanding of SGD, seawater intrusion, and chemical transport in coastal unconfined aquifers.
How Daily Temperature and Precipitation Distributions Evolve With Global Surface Temperature.
Authors: Samset Bjørn Hallvard , Stjern Camilla Weum , Lund Marianne Tronstad , Mohr Christian Wilhelm , Sand Maria , Daloz Anne Sophie
Published: October 2019

The climate is an aggregate of the mean and variability of a range of meteorological variables, notably temperature (T) and precipitation (P). While the impacts of an increase in global mean surface temperature (GMST) are commonly quantified through changes in regional means and extreme value distributions, a concurrent shift in the shapes of the distributions of daily T and P is arguably equally important. Here, we employ a 30‐member ensemble of coupled climate model simulations (CESM1 LENS) to consistently quantify the changes of regionally and seasonally resolved probability density functions of daily T and P as function of GMST. Focusing on aggregate regions covering both populated and rural zones, we identify large regional and seasonal diversity in the probability density functions and quantify where CESM1 projects the most noticeable changes compared to the preindustrial era. As global temperature increases, Europe and the United States are projected to see a rapid reduction in wintertime cold days, and East Asia to experience a strong increase in intense summertime precipitation. Southern Africa may see a shift to a more intrinsically variable climate but with little change in mean properties. The sensitivities of Arctic and African intrinsic variability to GMST are found to be particularly high. Our results highlight the need to further quantify future changes to daily temperature and precipitation distributions as an integral part of preparing for the societal and ecological impacts of climate change and show how large ensemble simulations can be a useful tool for such research.
Hearing the Sun Tock
Authors: Russell Christopher , Jian Lan , Luhmann Janet
Published: October 2019

The appearance of sunspots—their number, duration, and location—suggests that the dynamics of the Sun’s outer layer is synchronized with an internal clock.
Wildfire Smoke Traps Itself in Valleys
Authors: Barbuzano Javier
Published: October 2019

Simulations show how wildfire smoke increases atmospheric stability inside some valleys, creating a feedback loop that prevents its dispersion.
Forum Focuses on Climate and the 2020 U.S. Election
Authors: Showstack Randy
Published: October 2019

Former Trump environment official tries to defend the White House while others call for stronger action in the face of growing urgency.
Podcast: Plate Tectonics, the Theory That Changed Earth Science
Authors: Bompey Nanci
Published: October 2019

Third Pod from the Sun talks with pioneering geophysicist Xavier Le Pichon about what it was like to be a young scientist challenging deeply held theories.
Modern Planet Protection Rules Recommended and Welcomed
Authors: Cartier Kimberly
Published: October 2019

Protocols for the Moon and Mars, human exploration, ocean worlds, and the private sector are all due for a major overhaul.
Does Our Vision of Diversity Include Social Conservatives?
Authors: Abbott Benjamin , Radebaugh Jani , Jensen Jamie
Published: October 2019

Achieving our goals of advancing science and benefitting society depends on ideological diversity. Cultivating relationships and dialogue with ideological opponents creates compassion and progress.
Industry Leaders Dominate Trump’s Science and Tech Advisory Council
Authors: Showstack Randy
Published: October 2019

The council’s launch, more than 2 and a half years into the Trump presidency, has an initial membership that is heavy on industry, with just one academic and no representatives from civil society.
Could Seismic Networks Reveal Hard-to-Detect Nuclear Tests?
Authors: Derouin Sarah
Published: October 2019

In the age of monitoring nuclear weapons testing, existing regional seismic networks may be a key to discovering small, undetected explosions around the world.
Meteoric 10Be Reveals a Young, Active Accretionary Prism and Structurally Complex Décollement in the Vicinity of the 2011 Tohoku Earthquake Rupture
Authors: Regalla Christine , Bierman Paul , Rood Dylan H.
Published: October 2019

We present new meteoric 10Be concentration data from marine sediment cores recovered during Integrated Ocean Drilling Program Expedition 343 (JFAST) that help constrain the age, origin, and internal structure of the frontal prism at the Japan trench in the vicinity of the 2011 Tohoku‐oki M9 earthquake rupture. 10Be sediment ages from the lower portion of the frontal prism range from ~0–10 Ma, with >60% of analyzed samples above the décollement yielding young ages <2 Ma. Repetition and inversion of high‐over‐low 10Be‐concentration sediments indicate the presence of stratigraphic inversions that correspond to faulting and imbrication of late Miocene and Quaternary sediments. The density of faults inferred indicates that the frontal prism has a fault spacing on the order of 10 s of meters, and the identification of faults in the underthrust section suggests that the plate boundary décollement may be a zone with multiple slip surfaces. Comparison of 10Be concentrations in the frontal prism with those of the incoming and forearc slope sediments indicates that the majority of the prism is sourced from accretion of Pacific Plate sediments, rather than from reworked frontal prism or slope sediments. These data suggest that over at least the past ~1–2 Ma, the décollement preferentially has localized at or near the base of the incoming sediment section, with relatively efficient sediment accretion occurring even in the presence of subducted horst‐and‐graben topography.
Experimental Evaluation of Remanence Carriers Using the Microcoercivity‐Unblocking Temperature Diagram
Authors: Sato Masahiko , Terada Takuma , Mochizuki Nobutatsu , Tsunakawa Hideo
Published: October 2019

Knowledge of remanence carriers in recording media is crucial for obtaining reliable paleomagnetic data. In this paper, we report a newly developed technique to determine remanence carriers in natural rock samples that uses anhysteretic remanent magnetization (ARM) spectra in the microcoercivity (hc) and unblocking temperature (TUB) planes. The distribution of ARM carriers was determined via systematic stepwise demagnetization experiments of ARM combining thermal demagnetization and alternating field demagnetization treatments and calculating the change in ARM intensity on the hc‐TUB plane (hc‐TUB diagram). Samples from three basaltic lavas and two welded tuffs were analyzed. Combining the hc‐TUB diagram with the change in ARM coercivity spectra, both decreases and increases in magnetic minerals due to the thermal alteration during laboratory heating could be identified. From experimental samples, ARM carrier components were identified as being original rather than produced as a result of thermal alteration. In the case of the Izu‐Oshima 1986 A lava flow (1986La) sample, it was confirmed from the hc‐TUB diagram that high‐hc components can be separated using stepwise alternating field demagnetization treatment but not stepwise thermal demagnetization treatment. Paleointensity experiments were also conducted on Izu‐Oshima 1986 A lava flow samples. Two of the three paleointensity estimates were greater than the expected field intensity, suggesting a certain rock‐magnetic property that affects the paleointensity estimation. The hc‐TUB diagrams of the Izu‐Oshima 1986 A lava flow samples suggest that the differences in the paleointensity estimates were likely caused by different degrees of the high‐temperature oxidation state.
Modeling Satellite Gravity Gradient Data to Derive Density, Temperature, and Viscosity Structure of the Antarctic Lithosphere
Authors: Pappa F. , Ebbing J. , Ferraccioli F. , van der Wal W.
Published: October 2019

In this study we combine seismological and petrological models with satellite gravity gradient data to obtain the thermal and compositional structure of the Antarctic lithosphere. Our results indicate that Antarctica is largely in isostatic equilibrium, although notable anomalies exist. A new Antarctic Moho depth map is derived that fits the satellite gravity gradient anomaly field and is in good agreement with independent seismic estimates. It exhibits detailed crustal thickness variations also in areas of East Antarctica that are poorly explored due to sparse seismic station coverage. The thickness of the lithosphere in our model is in general agreement with seismological estimates, confirming the marked contrast between West Antarctica (<100 km) and East Antarctica (up to 260 km). Finally, we assess the implications of the temperature distribution in our model for mantle viscosities and glacial isostatic adjustment. The upper mantle temperatures we model are lower than obtained from previous seismic velocity studies. This results in higher estimated viscosities underneath West Antarctica. When combined with present‐day uplift rates from GPS, a bulk dry upper mantle rheology appears permissible.
Orogenic Root Delamination Induced by Eclogitization of Thickened Lower Crust in the Chinese Western Tianshan: Constraints From Adakites
Authors: Li Ning‐Bo , Niu He‐Cai , Yang Wu‐Bin , Lai Chun‐Kit , Zhao Zhen‐Hua
Published: October 2019

Crustal delamination induced by eclogitization of orogenic roots, in addition to plate subduction, is an important process that transfers crustal materials back into the mantle. Many previous studies have demonstrated a causal link between crustal delamination and eclogitization, but actual magmatic records of the process are rarely documented. Here we present detailed studies on two distinct late Paleozoic adakite suites in the Awulale Mountains (Chinese Western Tianshan), that is, the suites with high (HN) and low (LN) Nb/Ta ratios, to constrain the regional crustal delamination. Both igneous suites have adakitic affinity and formed by partial melting of the juvenile thickened lower crust with different residual mineral assemblages in their source regions. The late Carboniferous HN adakite has superchondritic Nb/Ta (21.4–23.3) and high Dy/Yb (2.66–2.88) ratios and may have formed via rutile‐bearing, eclogite‐controlled melting of the lower crust, implying crustal thickening and eclogitization. In contrast, the Permian LN adakites have varying and lower ranges of Nb/Ta (12.9–20.0) and Dy/Yb ratios (1.35–2.53), which were probably derived from mixing of garnet‐bearing amphibolite with minor rutile‐bearing, eclogite‐controlled melts, implying crustal thinning and the end of eclogitization. The succession of these two adakite suites suggests that during the late Carboniferous to early Permian, eclogitization of the orogenic root, accompanying successive crustal delaminations, occurred in this region. Accordingly, our results imply that adakites with different geochemical features are potential tracers for the mineralogy of orogenic roots and, importantly, provide convincing evidence for eclogitization‐induced crustal delamination in orogenic belts.
The Scale Characteristics and Formation Mechanism of Aeolian Sand Streamers Based on Large Eddy Simulation
Authors: Wang Ping , Feng ShengJun , Zheng XiaoJing , Sung Hyung Jin
Published: October 2019

Aeolian sand transport near the surface in the field often occurs in the form of sand streamers, which is very important to understand in‐depth the physics of aeolian transport and accurately predict the sand transport rate. In this paper, sand streamers were successfully reproduced by combining the Lagrangian trajectory simulation of particles with large eddy simulation of turbulence. The simulated sand streamers are hill‐like. Their characteristic scales are extracted by the two‐point correlation of sand concentration. It is found that sand streamers corresponding to the correlation threshold of
are 2.0–4.5 m long and 0.3–0.4 m wide, while 30–100 m long and 1.2–2.4 m wide for
, which are substantially consistent with the existing field observation results and increases with particle size. Conditional averaging method provided an ensemble‐mean visualization of flow structures that are responsible for the formation of streamers. It is found that sand streamers on a flat and erodible surface exist in the near‐surface wake area of large/very large scale turbulent motions (LSMs/VLSMs), indicating that sand streamers are the footprint of LSMs/VLSMs. Moreover, the characteristic scales of sand streamers will be affected by the splashing process of sand saltation. On a nonerodible surface, sand streamers trailing from upstream sandy surface become narrow though it can propagate downstream for a long distance.
Extreme Wet‐Bulb Temperatures in China: The Significant Role of Moisture
Authors: Wang Pinya , Leung L. Ruby , Lu Jian , Song Fengfei , Tang Jianping
Published: October 2019

This paper investigates the extreme wet‐bulb temperatures (TWs) in China, with a focus on understanding the relative contributions of temperature and moisture to the extremes. Analysis of station observations shows that daily extreme temperatures (T), specific humidity (q), and TWs generally co‐occur in Southeastern China, while extreme TW and T rarely overlap in the arid and semiarid North and Northwest China. Overall, q contributes more than T to extreme TWs, especially in North and Northwest China. Based on the relative contributions of q and T, regional extreme TW events are classified as q dominated and T dominated, respectively, to study their large‐scale environment. Cluster analysis of global reanalysis data shows that extreme TWs are generally accompanied by increased surface air temperature and humidity, concomitant with anomalous high pressure and notable water vapor flux convergence. However, important differences are also seen in the large‐scale environment during q‐dominated and T‐dominated extreme TWs. During q‐dominated extreme TWs, the large‐scale environment favors convection, as indicated by ascending motions, decreased downward solar radiation as well as increased precipitable water and near‐surface relative humidity. In contrast, during T‐dominated extreme TWs, convection is inhibited by the large‐scale environment that features descending motion and increased downward solar radiation, decreased precipitable water, and decreased relative humidity. Consistent with the contrasting environments, we demonstrate that T‐dominated extreme TWs tend to last longer than q‐dominated extremes. Given the significant role of moisture in extreme TWs, more research is needed to understand its impacts on heat stress now and in the future.