bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dual-band B-shaped antenna array for satellite applications
Authors: Hassan Muhammad Mateen , Hussain Muzhair , Khan Adnan Ahmed , Rashid Imran , Bhatti Farooq Ahmed 
Published: October 2020

AbstractThe paper presents a 1 × 2 B-shaped antenna array for dual-band operation at 4 and 8 GHz. The antenna design consists of a rectangular patch with two annular-strip lines fabricated on the top layer and finite ground plane on the bottom layer. The array is formed by designing an optimum T-shaped microstrip line for impedance matching. The dimensions of the antenna array are 78 × 36 × 1.6 mm3. Full-wave simulations have been conducted and the measured results are in good consent with the simulated results. The measured impedance bandwidth (reference −10 dB) has been observed at 3.84–4.16 and 7.78–8.38 GHz. Measured peak gain and radiation efficiency at 4 and 8 GHz are 8.3, 9.4 dB and 82.5 and 81.2%, respectively.
Development and Psychometric Properties of the Job Insecurity Appraisals Scale (JIAS-6)
Authors: Bazzoli Andrea , Brondino Margherita , De Witte Hans , Pasini Margherita 
Published: October 2020

Abstract. This contribution introduces the Job Insecurity Appraisals Scale (JIAS-6), a tool that measures job insecurity primary appraisals (i.e., challenge and hindrance). Starting from the transactional theory of stress and extending previous unpublished versions of the same scale, the authors developed JIAS-6, using two samples of Italian workers ( N1 = 204 and N2 = 328). JIAS also addresses methodological and theoretical limitations of other primary appraisal scales. In Study 1, using a calibration sample, a series of confirmatory factorial analyses (CFAs) were performed and results showed that the final version of the scale fits the data well, while Study 2 findings (using a validation sample) replicated those obtained in Study 1 and provided support for strict measurement invariance across contract type, age, and gender, while scalar invariance was supported across job insecurity levels. Furthermore, we provided evidence of the relationship between job insecurity appraisals measured by JIAS-6 and other theoretically relevant constructs. The initial validation of JIAS-6 opens several new fruitful lines of research for job insecurity scholars.
Signatures of Hydrologic Function Across the Critical Zone Observatory Network
Authors: Wlostowski Adam N. , Molotch Noah , Anderson Suzanne P. , Brantley Susan L. , Chorover Jon , Dralle David , Kumar Praveen , Li Li , Lohse Kathleen A. , Mallard John M. , McIntosh Jennifer C. , Murphy Sheila F. , Parrish Eric , Safeeq Mohammad , Seyfried Mark , Shi Yuning , Harman Ciaran 
Published: October 2020

AbstractDespite a multitude of small catchment studies, we lack a deep understanding of how variations in critical zone architecture lead to variations in hydrologic states and fluxes. This study characterizes hydrologic dynamics of 15 catchments of the U.S. Critical Zone Observatory (CZO) network where we hypothesized that our understanding of subsurface structure would illuminate patterns of hydrologic partitioning. The CZOs collect data sets that characterize the physical, chemical, and biological architecture of the subsurface, while also monitoring hydrologic fluxes such as streamflow, precipitation, and evapotranspiration. For the first time, we collate time series of hydrologic variables across the CZO network and begin the process of examining hydrologic signatures across sites. We find that catchments with low baseflow indices and high runoff sensitivity to storage receive most of their precipitation as rain and contain clay‐rich regolith profiles, prominent argillic horizons, and/or anthropogenic modifications. In contrast, sites with high baseflow indices and low runoff sensitivity to storage receive the majority of precipitation as snow and have more permeable regolith profiles. The seasonal variability of water balance components is a key control on the dynamic range of hydraulically connected water in the critical zone. These findings lead us to posit that water balance partitioning and streamflow hydraulics are linked through the coevolution of critical zone architecture but that much work remains to parse these controls out quantitatively.
Bayesian Inference of Mantle Viscosity From Whole‐Mantle Density Models
Authors: Rudolph M. L. , Moulik P. , Lekić V. 
Published: October 2020

AbstractThe long‐wavelength geoid is sensitive to Earth's mantle density structure as well as radial variations in mantle viscosity. We present a suite of inversions for the radial viscosity profile using whole‐mantle models that jointly constrain the variations in density, shear‐ and compressional‐wavespeeds using full‐spectrum tomography. We use a Bayesian approach to identify a collection of viscosity profiles compatible with the geoid, while enabling uncertainties to be quantified. Depending on tomographic model parameterization and data weighting, it is possible to obtain models with either positive‐ or negative‐buoyancy in the large low shear velocity provinces. We demonstrate that whole‐mantle density models in which density and VS variations are correlated imply an increase in viscosity below the transition zone, often near 1,000 km. Many solutions also contain a low‐viscosity channel below 650 km. Alternatively, models in which density is less‐correlated with VS—which better fit normal mode data—require a reduced viscosity region in the lower mantle. This feature appears in solutions because it reduces the sensitivity of the geoid to buoyancy variations in the lowermost mantle. The variability among the viscosity profiles obtained using different density models is indicative of the strong nonlinearities in modeling the geoid and the limited resolving power of the geoid kernels. We demonstrate that linearized analyses of model resolution do not adequately capture the posterior uncertainty on viscosity. Joint and iterative inversions of viscosity, wavespeeds, and density using seismic and geodynamic observations are required to reduce bias from prior assumptions on viscosity variation and scalings between material properties.
A Warm Summer is Unlikely to Stop Transmission of COVID‐19 Naturally
Authors: Su Ming , Peng Shushi , Chen Lili , Wang Bin , Wang Ying , Fan Xiarui , Dong Zhaomin 
Published: October 2020

AbstractThe outbreak of coronavirus disease 2019 (COVID‐19) showed various transmission rate (Rt) across different regions. The determination of the factors affecting transmission rate is urgent and crucial to combat COVID‐19. Here we explored variation of Rt between 277 regions across the globe and the associated potential socioeconomic, demographic, and environmental factors. At global scale, the Rt started to decrease approximately 2 weeks after policy interventions initiated. This lag from the date of policy interventions initiation to the date when Rt started to decrease ranges from 9 to 19 days, largest in Europe and North America. We find that proportion of elderly people or life expectancy can explain ~50% of variation in transmission rate across the 277 regions. The transmission rate at the point of inflection (RI) increases by 29.4% (25.2–34.0%) for 1% uptick in the proportion of people aged above 65, indicating that elderly people face ~2.5 times higher infection risk than younger people. Air temperature is negatively correlated with transmission rate, which is mainly attributed to collinearities between air temperature and demographic factors. Our model predicted that temperature sensitivity of RI is only −2.7% (−5.2–0%) per degree Celsius after excluding collinearities between air temperature and demographic factors. This low temperature sensitivity of RI suggests that a warm summer is unlikely to impede the spread of COVID‐19 naturally.
The Role of Shear Fabric in Controlling Breakdown Processes During Laboratory Slow‐Slip Events
Authors: Scuderi Marco M. , Tinti Elisa , Cocco Massimo , Collettini Cristiano 
Published: October 2020

AbstractUnderstanding the physical mechanisms at the origin of slow‐slip events has been proven a very challenging task. In particular, little is known on the role of fault heterogeneity during slow slip. In this study, we provide evidences that fault fabric controls slip velocity time histories during slow‐slip events generated in the laboratory. We performed experiments using a double‐direct biaxial shear apparatus and two different fault gouges, homogeneous quartz powder, and heterogeneous anhydrite/dolomite mixture. We measure details of fault slip to resolve the slip velocity function and volumetric deformation that, coupled with an analysis of the resulting microstructure, allow us to infer the mechanical processes at play. Our results show that slow‐slip events can be generated for both fault gouges when k ~ kc with similar values of breakdown work. The shear fabric exerts a strong influence during the coseismic breakdown stage. In quartz, where most of the slip occurs on a very localized slipping surface, the peak slip velocity is attained near the final stage of friction breakdown and therefore a relevant amount of the mechanical work is absorbed during slip acceleration. In anhydrite/dolomite mixture, the peak slip velocity is suddenly reached after a relatively small drop in friction, accompanied by fault dilation, implying that most of the mechanical work is absorbed during slip deceleration. For anhydrite/dolomite mixture these results are likely related to heterogeneous slip distribution along the observed foliation. Taken together, these observations suggest that the mechanics of slow‐slip events depends on shear zone fabric.
On the Contributions of Incipient Vortex Circulation and Environmental Moisture to Tropical Cyclone Expansion
Authors: Martinez Jonathan , Nam Chaehyeon Chelsea , Bell Michael M. 
Published: October 2020

AbstractThis study investigates the contributions of incipient vortex circulation and midlevel moisture to tropical cyclone (TC) expansion within an idealized numerical modeling framework. We find that the incipient vortex circulation places the primary constraint on TC expansion. Increasing the midlevel moisture further promotes expansion but mostly expedites the intensification process. The expansion rate for initially large vortices exhibits a stronger response to increasing the midlevel moisture compared to initially small vortices. Previous studies have noted a proclivity for relatively small TCs to stay small and relatively large TCs to stay large; that is, TCs possess a sort of “memory” with respect to their incipient circulation. We reproduce this finding with an independent modeling framework and further demonstrate that an initially large vortex can expand more quickly than its relatively smaller counterpart; therefore, with all other factors contributing to expansion held constant, the contrast in size between the two vortices will increase with time. Varying the incipient vortex circulation is associated with subsequent variations in the amount and scale of outer‐core convection. As the incipient vortex circulation decreases, outer‐core convection is relatively scarce and characterized by small‐scale, isolated convective elements. On the contrary, as the incipient vortex circulation increases, outer‐core convection abounds and is characterized by relatively large rainbands and mesoscale convective systems. A combined increase in the amount and scale of outer‐core convection permits an initially large vortex to converge a substantially greater amount of absolute angular momentum compared to its relatively smaller counterpart, resulting in distinct expansion rates.
Remote Sensing‐Based Modeling of the Bathymetry and Water Storage for Channel‐Type Reservoirs Worldwide
Authors: Liu Kai , Song Chunqiao , Wang Jida , Ke Linghong , Zhu Yunqiang , Zhu Jingying , Ma Ronghua , Luo Zhu 
Published: October 2020

AbstractEstimations of reservoir bathymetry and storage are of great significance due to their substantial impacts on hydrological processes and water resource management. However, existing approaches for reservoir bathymetry construction often rely on field measurements, which restricts their application at regional and global scales. This study proposes a novel Approach for Determining the BAthymetry and water storage of channel‐type Reservoirs, hereafter referred to as ADBAR, for which only open‐access digital elevation model (DEM) and satellite images are required. The basic idea of ADBAR is to utilize the geomorphological similarity and topographical continuity of the reservoir inundation area with its lateral valleys and upstream/downstream regions to predict underwater bathymetry. Forty‐eight reservoirs with different topographic and geometric characteristics were selected for method validation. The selected reservoirs were all impounded after the year 2000, so the modeled reservoir bathymetry can be validated by the “reference” reservoir storage calculated using the exposed topography in SRTM DEM and the mapped water extents from spectral images. The difference between the estimated and reference storages is about 13% on average. Furthermore, the modeled results in two selected basins with dense reservoir distributions, the Upper Yellow River Basin in China and the Tocantins River Basin in Brazil, are comparable with the documented effective storage capacities. The validations for both individual reservoirs and the two large basins demonstrate that ADBAR is a robust tool for estimating reservoir bathymetries and storage capacities and thus facilitates the modeling of reservoir impacts on water budgets at large and global scales.
Influence of Capillarity on Relative Permeability in Fractional Flows
Authors: Zou Shuangmei , Liu Yang , Cai Jianchao , Armstrong Ryan T. 
Published: October 2020

AbstractThe effect of capillary pressure on multiphase flow is described by the capillary pressure gradient term in the fractional flow equation. This term is typically neglected during core‐flooding experiments, as it is not easily accessible. However, the capillary pressure is not constant during core flooding owing to a capillary pressure discontinuity at the core outlet. By imaging spatial fluid distributions under two‐phase steady‐state flow, we determine in situ phase saturations and capillary pressures from interfacial curvature measurements along an entire core, thus achieving the assessment of the capillary pressure gradient and its influence on multiphase flow. We demonstrate how the pore‐scale capillary pressure gradient affects multiphase flow and, in turn, the core‐scale relative permeability measurements. Further, an alternative approach to determining relative permeability from a single fractional flow experiment is proposed. The approach provides a range of relative permeabilities for a single fractional flow experiment and does not require capillary‐end correction, as the formulation directly accounts for the effect of capillary pressure on the flow.
Quantifying the Effect of Subcritical Water Repellency on Sorptivity: A Physically Based Model
Authors: Shillito R. M. , Berli M. , Ghezzehei T. A. 
Published: October 2020

AbstractSoil water wettability or water repellency is a phenomenon that can affect infiltration and, ultimately, runoff. Thus, there is a need to develop a model that can quantitatively capture the influence of water repellency on infiltration in a physically meaningful way and within the framework of existing infiltration theory. The analytical model developed in this study relates soil sorptivity (an infiltration parameter) with contact angle (a direct measure of water repellency) for variably saturated media. The model was validated with laboratory experiments using a silica sand of known properties treated to produce controlled degrees of water repellency. The measured contact angle and sorptivity values closely matched the model‐predicted values. Further, the relationship between the frequently used water drop penetration time test (used to assess water repellency) and sorptivity was illustrated. Finally, the direct impact of water repellency on saturated hydraulic conductivity was investigated due to its role in infiltration equations and to shed light on inconsistent field observations. It was found that water repellency had minimal effect on the saturated hydraulic conductivity of structureless sand. A quantitative model for infiltration incorporating the effect of water repellency is particularly important for post‐fire hydrologic modeling of burned areas exhibiting water repellent soils.
Charting Pathways Toward Sustainability for Aquifers Supporting Irrigated Agriculture
Authors: Butler J. J. , Bohling G. C. , Whittemore D. O. , Wilson B. B. 
Published: October 2020

AbstractThe question of how much longer groundwater can support large‐scale agricultural production is one of global significance. Many of the world's regional aquifers supporting irrigated agriculture are on a trajectory toward resource depletion. In the absence of alternative water supplies, the only viable near‐term (few to several decades) option for redirecting these heavily stressed systems on to more sustainable paths is to reduce pumping. The key issues therefore become how much should pumping be reduced to significantly extend an aquifer's lifetime and what is the likelihood of attaining a sustainable condition. We have developed a water‐balance approach to glean insights into these issues and chart pathways toward more sustainable states. An aquifer's response to pumping reductions heavily depends on the net inflow component of an aquifer's water budget, both in terms of its magnitude and how it decreases with time in response to reductions. If a reduction leads to a pumping rate that is above net inflow, the aquifer lifespan can often be extended by a factor of two or more, but depletion will be the final outcome. In contrast, if a reduction results in a pumping rate more than 10% below net inflow, a lengthy period of apparent sustainability will result. In that case, the aquifer lifespan may be extended long enough so that other options, such as large‐scale water transfers or development of more sustainable crop mixes, become viable. These concepts are demonstrated using examples based on an ongoing experiment in pumping reductions in the High Plains aquifer.
A microfluidic platform for cultivating ovarian cancer spheroids and testing their responses to chemotherapies
Authors: Dadgar Neda , Gonzalez-Suarez Alan M. , Fattahi Pouria , Hou Xiaonan , Weroha John S. , Gaspar-Maia Alexandre , Stybayeva Gulnaz , Revzin Alexander 
Published: October 2020

AbstractThere is increasing interest in utilizing in vitro cultures as patient avatars to develop personalized treatment for cancer. Typical cultures utilize Matrigel-coated plates and media to promote the proliferation of cancer cells as spheroids or tumor explants. However, standard culture conditions operate in large volumes and require a high concentration of cancer cells to initiate this process. Other limitations include variability in the ability to successfully establish a stable line and inconsistency in the dimensions of these microcancers for in vivo drug response measurements. This paper explored the utility of microfluidics in the cultivation of cancer cell spheroids. Six patient-derived xenograft (PDX) tumors of high-grade serous ovarian cancer were used as the source material to demonstrate that viability and epithelial marker expression in the microfluidic cultures was superior to that of Matrigel or large volume 3D cultures. To further demonstrate the potential for miniaturization and multiplexing, we fabricated multichamber microfluidic devices with integrated microvalves to enable serial seeding of several chambers followed by parallel testing of several drug concentrations. These valve-enabled microfluidic devices permitted the formation of spheroids and testing of seven drug concentrations with as few as 100,000 cancer cells per device. Overall, we demonstrate the feasibility of maintaining difficul-to-culture primary cancer cells and testing drugs in a microfluidic device. This microfluidic platform may be ideal for drug testing and personalized therapy when tumor material is limited, such as following the acquisition of biopsy specimens obtained by fine-needle aspiration.
Exosome-mediated metabolic reprogramming: the emerging role in tumor microenvironment remodeling and its influence on cancer progression
Authors: Yang Enli , Wang Xuan , Gong Zhiyuan , Yu Miao , Wu Haiwei , Zhang Dongsheng 
Published: October 2020

AbstractMetabolic reprogramming is reported to be one of the hallmarks of cancer, which is an adaptive mechanism by which fast-growing cancer cells adapt to their increasing energy demands. Recently, extracellular vesicles (EVs) known as exosomes have been recognized as crucial signaling mediators in regulating the tumor microenvironment (TME). Meanwhile, the TME is a highly heterogeneous ecosystem incorporating cancer cells, fibroblasts, adipocytes, endothelial cells, mesenchymal stem cells, and extracellular matrix. Accumulated evidence indicates that exosomes may transfer biologically functional molecules to the recipient cells, which facilitate cancer progression, angiogenesis, metastasis, drug resistance, and immunosuppression by reprogramming the metabolism of cancer cells and their surrounding stromal cells. In this review, we present the role of exosomes in the TME and the underlying mechanism of how exosomes exacerbate tumor development through metabolic reprogramming. In addition, we will also discuss the potential role of exosomes targeting metabolic process as biomarkers for tumor diagnosis and prognosis, and exosomes-mediated metabolic reprogramming as potential targets for cancer therapy. Furthermore, a better understanding of the link between exosomes and metabolic reprogramming, and their impact on cancer progression, would provide novel insights for cancer prevention and treatment in the future.
Niche differentiation and evolution of the wood decay machinery in the invasive fungus Serpula lacrymans
Authors: Hess Jaqueline , Balasundaram Sudhagar V , Bakkemo Renee I , Drula Elodie , Henrissat Bernard , Högberg Nils , Eastwood Daniel , Skrede Inger 
Published: October 2020

Abstract
Ecological niche breadth and the mechanisms facilitating its evolution are fundamental to understanding adaptation to changing environments, persistence of generalist and specialist lineages and the formation of new species. Woody substrates are structurally complex resources utilized by organisms with specialized decay machinery. Wood-decaying fungi represent ideal model systems to study evolution of niche breadth, as they vary greatly in their host range and preferred decay stage of the substrate. In order to dissect the genetic basis for niche specialization in the invasive brown rot fungus Serpula lacrymans, we used phenotyping and integrative analysis of phylogenomic and transcriptomic data to compare this species to wild relatives in the Serpulaceae with a range of specialist to generalist decay strategies. Our results indicate specialist species have rewired regulatory networks active during wood decay towards decreased reliance on enzymatic machinery, and therefore nitrogen-intensive decay components. This shift was likely accompanied with adaptation to a narrow tree line habitat and switch to a pioneer decomposer strategy, both requiring rapid colonization of a nitrogen-limited substrate. Among substrate specialists with narrow niches, we also found evidence for pathways facilitating reversal to generalism, highlighting how evolution may move along different axes of niche space.