bluuebunny/crossref_metadata_2025_split huggingface dataset:
The smoothing of landscapes during snowfall with no wind
Authors: FILHOL SIMON , STURM MATTHEW 
Published: March 2019

ABSTRACTEvery winter, snowy landscapes are smoothed by snow deposition in calm conditions (no wind). In this study, we investigated how vertically falling snow attenuates topographic relief at horizontal scales less than or approximately equal to snow depth (e.g., 0.1–10 m). In a set of three experiments under natural snowfall, we observed the particle-scale mechanisms by which smoothing is achieved, and we examined the cumulative effect at the snowpack scale. The experiments consisted of (a) a strobe-light box for tracking the trajectories of snowflakes at deposition, (b) allowing snow to fall through a narrow gap (40 mm) and examining snow accumulation above and below the gap, and (c) allowing snow to accumulate over a set of artificial surfaces. At the particle scale, we observed mechanisms enhancing (bouncing, rolling, ejection, breakage, creep, metamorphism) and retarding (interlocking, cohesion, adhesion, sintering) the rate of smoothing. The cumulative effect of these mechanisms is found to be driven by snowpack surface curvature, introducing a directional bias in the lateral transport of snow particles. Our findings suggest that better quantification of the mechanisms behind smoothing by snow could provide insights into the evolution of snow depth variability, and snow-vegetation interactions.
EPONYMY, ENCOUNTERS, AND LOCAL KNOWLEDGE IN RUSSIAN PLACE NAMING IN THE PACIFIC ISLANDS, 1804–1830
Authors: DOUGLAS BRONWEN , GOVOR ELENA 
Published: March 2019

AbstractThis history of Russian place naming in the Pacific Islands from 1804 to 1830 systematically juxtaposes, correlates, and compares toponyms inscribed in varied genres of Russian texts: map, atlas, journal, narrative, and hydrographic treatise. Its empirical core comprises place names bestowed or recorded by naval officers and naturalists in eastern and northern Pacific archipelagoes during expeditions led by the Baltic German circumnavigators Krusenstern (1803–6), Kotzebue (1815–18), Bellingshausen (1819–21), and Lütke (1826–9). We address the interplay of personality, precedent, circumstance, and embodied encounters in motivating voyagers’ toponymic choices and their material expressions. We consider diverse textual movements from located experience, to specific inscription, to synthesis. Russian toponyms constituted part of the vast stock of historical raw material from which Krusenstern later created the authoritative pioneerAtlas de l'Océan pacifique(1824–7). This toponymic focus is scaffolding for a dual ethnohistorical inquiry: into the implications for Russian toponymy of Indigenous agency during situated encounters with people and places; and into the relative significance of loca'l knowledge conveyed to Russian voyagers by Indigenous interlocutors, and its presence or absence in particular sets of toponyms or different genres of text.
On the Cable Pseudo-Drag Problem of Cable-Driven Parallel Camera Robots at High Speeds
Authors: Wei Huiling , Qiu Yuanying , Sheng Ying 
Published: March 2019

SummaryThis paper presents a control strategy for solving the cable pseudo-drag problem of cable-driven parallel camera robots at high speeds. The control strategy belongs to a hybrid position/tension control method based on cable tension optimization. The cable catenary model and cable pseudo-drag problem are considered firstly. Then, the dynamic model of the cable-driven parallel camera robot is established. The cable tension optimization is proposed. And then a control strategy is put forward and its stability is proved. Simulation results of a four-cable camera robot are presented and discussed.
The voting paradox … with a single voter? Implications for transitivity in choice under risk
Authors: Butler David , Blavatskyy Pavlo 
Published: March 2019

AbstractThe voting paradox occurs when a democratic society seeking to aggregate individual preferences into asocialpreference reaches an intransitive ordering. However it is not widely known that the paradox may also manifest for anindividualaggregating over attributes of risky objects to form a preference over those objects. When this occurs, the relation ‘stochastically greater than’ is not always transitive and so transitivity need not hold between those objects. We discuss the impact of other decision paradoxes to address a series of philosophical and economic arguments against intransitive (cyclical) choice, before concluding that intransitive choices can be justified.
China's UN Peacekeeping in Mali and Comprehensive Diplomacy
Authors: Lanteigne Marc 
Published: March 2019

AbstractChina's increasing participation in United Nations peacekeeping operations reached a milestone in 2013 when Beijing agreed to send a large detachment of personnel, including combat forces for the first time, to support UN peacekeeping operations in Mali after that country fell into civil war. This commitment was also distinct in that unlike other African countries where Beijing has supplied peacekeepers, Mali is not a major trading partner with China. However, this mission has both cemented Beijing's greater commitment to building African partnerships as well as demonstrating its determination to move beyond “resource diplomacy” and towards a more comprehensive approach to engaging the continent. Although China has warmed to the principles of humanitarian intervention in civil conflicts, Mali has been a critical test of China's ability to participate in UN operations in a country which is still facing ongoing violence. The Mali mission is an important step in Beijing's turn towards greater realpolitik in Chinese Beijing's peacekeeping policies in keeping with its great power status. At the same time, participation in the Mali mission has been beneficial for China, not only in helping to build the country's peacekeeping credentials in Africa but also in underscoring China's increasingly distinct views on addressing intervention in civil conflicts.
Microstructural Features of Recycled Aggregate Concrete: From Non-Structural to High-Performance Concrete
Authors: Pedro Diogo , Guedes Mafalda , de Brito Jorge , Evangelista Luís 
Published: March 2019

AbstractThe use of concrete-recycled aggregates to produce high-performance concrete is limited by insufficient correlation between resulting microstructure and its influence on mechanical performance reproducibility. This work addresses this issue in a sequential approach: concrete microstructure was systematically analyzed and characterized by scanning electron microscopy and results were correlated with concrete compressive strength and water absorption ability. The influence of replacing natural aggregates (NA) with recycled concrete aggregates (RCA), with different source concrete strength levels, of silica fume (SF) addition and of mixing procedure was tested. The results show that the developed microstructure depends on the concrete composition and is conditioned by the distinct nature of NA, recycled aggregates from high-strength source concrete, and recycled aggregates from low-strength source concrete. SF was only effective at concrete densification when a two-stage mixing approach was used. The highest achieved strength in concrete with 100% incorporation of RCA was 97.3 MPa, comparable to that of conventional high-strength concrete with NA. This shows that incorporation of significant amounts of RCA replacing NA in concrete is not only a realistic approach to current environmental goals, but also a viable route for the production of high-performance concrete.
SIW resonator fed horn mounted compact DRA with enhanced gain for multiband applications
Authors: Kumar Pramod , Kumar Jitendra , Singh Shailendra , Utkarsh  , Dwari Santanu 
Published: March 2019

AbstractA novel design of compact and light-weight horn mounted cylindrical dielectric resonator antenna (CDRA) fed by substrate integrated waveguide (SIW) resonator has been investigated for high gain and multiband applications. SIW resonator contains two closely spaced longitudinal slots of equal length and unequal width to excite the CDRA. These slots are responsible for introducing triple resonating bands. The excited mode in dielectric resonator by longitudinal slots is EH11δ mode. The achieved impedance bandwidths are 65, 180, and 240 MHz at resonant frequencies 9.78, 10.58, and 11.84 GHz, respectively, for |S11| &lt;−10 dB. Copper-taped horn enhances the gain of antenna more than 2 dB for all resonating bands. The measured peak value of gain is 9.3 dBi at ~11.84 GHz.
Sexual dimorphism on aortic remodelling in rats offspring from diabetic mothers and the role of flaxseed oil in this effect
Authors: Vicente G. C. , Correia-Santos A. M. , Chagas M. A. , Boaventura G. T. 
Published: March 2019

AbstractDiabetes during pregnancy is associated with aortic remodelling in the fetus, stimulating the development of cardiovascular diseases in adult life. However, studies suggest that the use of foods high in omega-3 fatty acid, such as flaxseed oil, may reverse this effect of metabolic programming. This study aimed at investigating whether the effects of diabetes in mothers are passed on to their offspring in a gender-specific manner and whether the flaxseed oil used during pregnancy and lactation reverses or not the possible negative effects of this programming. Diabetic female rats (n = 18) were mated and allocated into three groups (n = 6): high-fat group (HG); flaxseed oil group (FOG) and control group (CG) (nondiabetic rats) during pregnancy and lactation. On the 21st day, male and female pups were weaned on a standard diet until 180 days. Aorta histomorphometry was analysed. Intima-media layer thickness was larger in FOG than CG in male (+15%) and than HG in female (+13.7%). Male FOG (+11.5%) showed higher amount of elastic fibre than CG. Maternal intake of flaxseed oil during pregnancy and lactation of diabetic mothers program the offspring to increase aorta intima-media layer thickness in adulthood and preserves aorta elastic fibres deposition in male offspring.
Electromagnetic Simulations of Solar Radio Emissions
Authors: Henri P. , Sgattoni A. , Briand C. , Amiranoff F. , Riconda C. 
Published: March 2019

AbstractSolar radio emissions are electromagnetic waves emitted in the solar wind as a consequence of electron beams accelerated during solar flares or interplanetary shocks such as interplanetary coronal mass ejections. Different physical mechanisms have been suggested to describe their origin. A good understanding of the emission process would enable to infer the kinetic energy transferred from accelerated electrons to radio waves. Even if the electrostatic case has been extensively studied, full electromagnetic simulations were attempted only recently. In this work, we report large‐scale 2D3V electromagnetic particle‐in‐cell simulations that enable to identify the generation of both electrostatic and electromagnetic waves originated by a succession of plasma instabilities. They confirm that an efficient mechanism to generate solar radio emissions close to T2f, the harmonic of the plasma frequency, is a multistage model based on a succession of nonlinear three‐wave interaction processes. Through a parametric study of the electron beam parameters, we show that (i) the global efficiency of the multistep conversion mechanism from the electron beam kinetic energy to the T2f radio wave is independent of the beam parameters, approximately 10−5 in all tested configurations, while (ii) the directivity of the electromagnetic radio wave strongly depends on the origin electron beam. Those results represent a step forward toward the use of solar wind radio emissions, observed remotely, as a diagnostic for the properties of the electron beam located at the source of the radio emission, and therefore to eventually better characterize remotely electron acceleration mechanisms in space regions not directly accessible to in situ measurements.
Validation, Stability, and Consistency of MODIS Collection 6.1 and VIIRS Version 1 Deep Blue Aerosol Data Over Land
Authors: Sayer Andrew M. , Hsu N. Christina , Lee Jaehwa , Kim Woogyung V. , Dutcher Steven T. 
Published: March 2019

AbstractThe Deep Blue (DB) algorithm has been used to retrieve aerosol optical depth (AOD) and Ångström exponent (AE) over land from multiple satellite instruments, including the Moderate Resolution Imaging Spectroradiometers (MODIS) aboard the Terra and Aqua platforms and the Visible Infrared Imaging Radiometer Suite (VIIRS). This study first validates the latest MODIS (Collection 6.1) and VIIRS (Version 1) DB data products against Aerosol Robotic Network observations. On global average, the typical level of uncertainty in AOD is slightly better than ±(0.05 + 20%) relative to Aerosol Robotic Network. AE is quantitatively more uncertain but qualitatively shows skill at distinguishing between fine‐mode and coarse‐mode dominated aerosol columns. Results are also compared with the previous MODIS Collection 6. The stability of the three DB data sets ranges from 0.005–0.01 AOD per decade. Second, spatial and temporal patterns in AOD and AE are compared between the three data sets. It is found that they all show similar patterns of spatial coverage, which is predominantly linked to cloud cover, snow, and polar night. Regional time series of AOD also show highly consistent seasonal and interannual variations and are strongly correlated, although have offsets in some regions due to a combination of algorithmic and sensor‐related differences.
Key Elements of Turbulence Closures for Simulating Deep Convection at Kilometer‐Scale Resolution
Authors: Shi Xiaoming , Chow Fotini Katopodes , Street Robert L. , Bryan George H. 
Published: March 2019

AbstractKilometer‐scale grid spacing is increasingly being used in regional numerical weather prediction and climate simulation. This resolution range is in the terra incognita, where energetic eddies are partially resolved and turbulence parameterization is a challenge. The Smagorinsky and turbulence kinetic energy 1.5‐order models are commonly used at this resolution range, but, as traditional eddy‐diffusivity models, they can only represent forward‐scattering turbulence (downgradient fluxes), whereas the dynamic reconstruction model (DRM), based on explicit filtering, permits countergradient fluxes. Here we perform large‐eddy simulation of deep convection with 100‐m horizontal grid spacing and use these results to evaluate the performance of turbulence schemes at 1‐km horizontal resolution. The Smagorinsky and turbulence kinetic energy 1.5 schemes produce large‐amplitude errors at 1‐km resolution, due to excessively large eddy diffusivities attributable to the formulation of the squared moist Brunt‐Väisälä frequency (
). With this formulation in cloudy regions, eddy diffusivity can be excessively increased in “unstable” regions, which produce downward (downgradient) heat flux in a conditionally unstable environment leading to destabilization and further amplification of eddy diffusivities. A more appropriate criterion based on saturation mixing ratio helps eliminate this problem. However, shallow clouds cannot be simulated well in any case at 1‐km resolution with the traditional models, whereas DRM allows for countergradient heat flux for both shallow and deep convection and predicts the distribution of clouds and fluxes satisfactorily. This is because DRM employs an eddy diffusivity model that is dynamically adjusted and a reconstruction approach that allows countergradient fluxes.
Eastern Mediterranean Deep Water Formation During Sapropel S1: A Reconstruction Using Geochemical Records Along a Bathymetric Transect in the Adriatic Outflow Region
Authors: Filippidi A. , De Lange G. J. 
Published: March 2019

AbstractEastern Mediterranean thermohaline circulation is directly influenced by middle‐ and low‐latitude climate systems. The dramatic paleoclimate changes during the last African Humid Period (~10–6 ka BP) were captured in Mediterranean sediments as the distinctly organic‐rich unit sapropel S1. Here, deepwater formation variability during S1 deposition is reconstructed. We use geochemical records of three cores along a bathymetric transect (775‐, 1,359‐, and 1,908‐m water depths), at the transition between the Adriatic DW‐ formation area and the Eastern Mediterranean. In all three cores, sedimentation rates are distinctly higher during S1, corresponding with enhanced runoff emanating from the Adriatic hinterland. Hence, major runoff did not only come from southern but also from northern borderlands in this period. During sapropel formation, enhanced levels of primary productivity occurred in the surface waters and oxygen‐depleted conditions in the bottom waters for all sites. Conditions for sediment and bottom‐water below ~1.4 km water depth were sulfidic throughout S1, but for intermediate depth (775 m) were anoxic only during the first part (S1a). Bottom‐water oxygenation interrupted S1 formation at water depths down to ~1.4 km, during two brief episodes, at 8.2 and 7.4 cal. ka BP. From the 7.4 cal. ka BP ventilation onward, the transition to more oxygenated bottom‐water conditions was more progressive for the intermediate water depth site (775 m) than for the deeper sites. Conditions remained fully oxic for all water depths following the S1‐MarkerBed ventilation event. Possibly, the onset of continuously oxic conditions started slightly earlier at intermediate depth (775 m; 6.6 ± 0.3 cal. ka BP) than at greater depths (1,359 m, 1,908 m; 6.0 ± 0.3 cal. ka BP).
Cellular energy stress induces AMPK-mediated regulation of glioblastoma cell proliferation by PIKE-A phosphorylation
Authors: Zhang Shuai , Sheng Hao , Zhang Xiaoya , Qi Qi , Chan Chi Bun , Li Leilei , Shan Changliang , Ye Keqiang 
Published: March 2019

AbstractPhosphoinositide 3-kinase enhancer-activating Akt (PIKE-A), which associates with and potentiates Akt activity, is a pro-oncogenic factor that play vital role in cancer cell survival and growth. However, PIKE-A physiological functions under energy/nutrient deficiency are poorly understood. The AMP-activated protein kinase (AMPK) is an evolutionarily conserved serine/threonine kinase that is a principal regulator of energy homeostasis and has a critical role in metabolic disorders and cancers. In this present study, we show that cellular energy stress induces PIKE-A phosphorylation mediated by AMPK activation, thereby preventing its carcinogenic action. Moreover, AMPK directly phosphorylates PIKE-A Ser-351 and Ser-377, which become accessible for the interaction with 14-3-3β, and in turn stimulates nuclear translocation of PIKE-A. Nuclear PIKE-A associates with CDK4 and then disrupts CDK4-cyclinD1 complex and inhibits the Rb pathway, resulting in cancer cell cycle arrest. Our data uncover a molecular mechanism and functional significance of PIKE-A phosphorylation response to cellular energy status mediated by AMPK.
Cryo-thermal therapy induces macrophage polarization for durable anti-tumor immunity
Authors: He Kun , Jia Shengguo , Lou Yue , Liu Ping , Xu Lisa X. 
Published: March 2019

AbstractMany cancer therapies are being developed for the induction of durable anti-tumor immunity, especially for malignant tumors. The activation of antigen-presenting cells (APCs), including macrophages and dendritic cells (DCs), can bridge innate and adaptive immune responses against tumors. However, APCs have an immunosuppressive phenotype and reversing it for effective tumor-specific antigen presenting is critical in developing new cancer treatment strategies. We previously developed a novel cryo-thermal therapy to treat malignant melanoma in a mouse model; long-term survival and durable anti-tumor immunity were achieved, but the mechanism involved was unclear. This study revealed cryo-thermal therapy-induced macrophage polarization to the M1 phenotype and modulated the phenotypic and functional maturation of DCs with high expression of co-stimulatory molecules, increased pro-inflammatory cytokine production, and downregulated immuno-inhibitory molecule expression. Further, we observed CD4+T-cell differentiation into Th1 and cytotoxic T-cell sub-lineages and generation of cytotoxic CD8+T cells, in which M1 macrophage polarization had a direct, important role. The results indicated that cryo-thermal-induced macrophage polarization to the M1 phenotype was essential to mediate durable anti-tumor immunity, leading to long-term survival. Thus, cryo-thermal therapy is a promising strategy to reshape host immunosuppression, trigger persistent memory immunity for tumor eradication, and inhibit metastasis in the long term.
Scale-free networks are rare
Authors: Broido Anna D. , Clauset Aaron 
Published: March 2019

AbstractReal-world networks are often claimed to be scale free, meaning that the fraction of nodes with degree k follows a power law k−α, a pattern with broad implications for the structure and dynamics of complex systems. However, the universality of scale-free networks remains controversial. Here, we organize different definitions of scale-free networks and construct a severe test of their empirical prevalence using state-of-the-art statistical tools applied to nearly 1000 social, biological, technological, transportation, and information networks. Across these networks, we find robust evidence that strongly scale-free structure is empirically rare, while for most networks, log-normal distributions fit the data as well or better than power laws. Furthermore, social networks are at best weakly scale free, while a handful of technological and biological networks appear strongly scale free. These findings highlight the structural diversity of real-world networks and the need for new theoretical explanations of these non-scale-free patterns.
Essential and non-overlapping IL-2Rα-dependent processes for thymic development and peripheral homeostasis of regulatory T cells
Authors: Toomer Kevin H. , Lui Jen Bon , Altman Norman H. , Ban Yuguang , Chen Xi , Malek Thomas R. 
Published: March 2019

AbstractIL-2R signaling is essential for regulatory T cell (Treg) function. However, the precise contribution of IL-2 during Treg thymic development, peripheral homeostasis and lineage stability remains unclear. Here we show that IL-2R signaling is required by thymic Tregs at an early step for expansion and survival, and a later step for functional maturation. Using inducible, conditional deletion of CD25 in peripheral Tregs, we also find that IL-2R signaling is indispensable for Treg homeostasis, whereas Treg lineage stability is largely IL-2-independent. CD25 knockout peripheral Tregs have increased apoptosis, oxidative stress, signs of mitochondrial dysfunction, and reduced transcription of key enzymes of lipid and cholesterol biosynthetic pathways. A divergent IL-2R transcriptional signature is noted for thymic Tregs versus peripheral Tregs. These data indicate that IL-2R signaling in the thymus and the periphery leads to distinctive effects on Treg function, while peripheral Treg survival depends on a non-conventional mechanism of metabolic regulation.