bluuebunny/crossref_metadata_2025 huggingface dataset:
Utility of Diffusion‐Weighted Imaging for Guiding Clinical Management of Patients With Kidney Transplant: A Prospective Study
Authors: Ni Xuefeng , Wang Wei , Li Xue , Li Yanjun , Chen Jinsong , Shi Donghong , Wen Jiqiu
Published: February 2020

Background

Although biopsy is essential for the diagnosis and management of kidney transplant recipients, it is invasive. Intravoxel incoherent motion diffusion‐weighted imaging (IVIM‐DWI) is a noninvasive technique that can assess both capillary perfusion and tissue diffusion.

Purpose

To evaluate the capability of IVIM‐DWI as a differentiation of kidney transplant patients who need clinical intervention from those who need not.

Study Type

Prospective.

Subjects

In all, 33 kidney transplant patients who needed clinical intervention and 19 who need not.

Field Strength/Sequence

3.0T; IVIM‐DWI with a single‐shot echo planar imaging sequence.

Assessment

All patients underwent kidney transplant biopsy and IVIM‐DWI scans. Patients were dichotomized into those who needed clinical intervention (CHANGE group) and those who need not (Non‐CHANGE group) based on biopsy results. The values of total apparent diffusion coefficient (ADCT), diffusion coefficient (D), and perfusion fraction (f) were acquired from renal cortex and medulla, respectively. The area under the curve (AUC) was calculated and compared.

Statistical Tests

Independent Student's t‐test, receiver‐operating characteristic curve, and Spearman correlation analysis.

Results

All the cortical and medullary DWI parameters in the CHANGE group were significantly lower than those in the Non‐CHANGE group (all P ≤ 0.012). Except for medullary fp, all DWI parameters in both the cortex and the medulla were inversely correlated with both the chronic (ρ ranging from –0.33 to –0.54, all P ≤ 0.02) and acute (ρ ranging from –0.35 to –0.60, all P ≤ 0.01) composite scores. Cortical ADCT and D had the largest AUC and specificity of 0.84 and 75.8%, respectively. Combined use of cortical D and medullary fp at each optimal cutoff point yielded a specificity of 90.9%.

Data Conclusion

DWI demonstrated potential as a noninvasive biomarker to allow the stratification of patients into categories in which kidney allograft biopsy results are or are not likely to change clinical management.

Level of Evidence

1

Technical Efficacy Stage

5 J. Magn. Reson. Imaging 2020;52:565–574.
Soil incubation study showed biogas digestate to cause higher and more variable short‐term N2O and N2 fluxes than mineral‐N
Authors: Buchen-Tschiskale Caroline , Hagemann Ulrike , Augustin Jürgen
Published: February 2020

Today, a large share of mineral fertilizer is substituted by biogas digestates. Biogas digestates are known to promote N2O production, compared to mineral fertilizer. In particular, the initial phase following fertilizer application is crucial for the N gas release as N2O and also N2. However, this period impact has been rarely investigated, especially not across various field sites. Thus, undisturbed soil cores from two fertilizer types (biogas digestate vs. mineral fertilizer) at five sites with different site characteristics were investigated in a short‐term laboratory experiment under N2‐free helium–oxygen incubation atmosphere. Across sites, biogas digestate soil cores showed significantly higher absolute N2O fluxes compared to mineral fertilizer soil cores, even though this effect was dominated by samples from one site (Dornburg with the highest biogas digestate fertilization rate). Also relative N2O fluxes showed a similar tendency. On average, absolute and relative N2 fluxes differed between the two fertilizer types, while N2 fluxes were highest at the Dornburg site. A N2O/(N2O+N2) ratio of denitrification below or equal to 0.5 clearly highlighted the importance of N2O reduction to N2 for three of five the biogas digestate soil cores. Soil characteristics like bulk density and water‐filled pore space as proxies for gas diffusivity in soil, as well as N availability (
,
), significantly affected the N2O and N2 fluxes from the biogas digestate soil cores. While this study presents data on short‐term N2O and N2 fluxes, there is a need for further studies in order to investigate the dynamics, the duration of the observed effects and their significance at the field scale.
Carbonization of Carboxylate‐Functionalized Polymers of Intrinsic Microporosity for Water Treatment
Authors: Jeon Jun Woo , Kim Hee Joong , Jung Kyung Hwa , Lee Jinyoung , Kim Yong Seok , Kim Byoung Gak , Lee Jong‐Chan
Published: February 2020

Considering the variations in their pore characteristics and heterogeneity, the carbonization process of carboxylate‐functionalized polymers of intrinsic microporosity (PIM‐COOH) is investigated and the resulted membranes are tested for water treatment. The four distinct types of sub‐nanosized membranes with different oxygen‐to‐carbon ratios are prepared at four different temperatures: the pristine polymer membrane, crosslinked membrane via thermal decarboxylation, amorphous carbon membrane, and graphitic carbon membrane. Notably, the sub‐1 nm micropores of all the heat‐treated samples that do not exhibit a broadening pore size distribution are still retained. Nanofiltration performance is investigated using an aqueous MgSO4 solution (2000 ppm), pure water, and a series of the defect‐free, sub‐1 nm microporous membranes. While retaining the salt rejection, the water flux of the membranes increases with the pyrolysis temperature owing to their low friction property.
Advanced numerical analyses by the Non‐Smooth Contact Dynamics method of an ancient masonry bell tower
Authors: Ferrante Angela , Clementi Francesco , Milani Gabriele
Published: February 2020

Advanced numerical analyses were carried out in order to assess the nonlinear dynamical behaviour of the bell tower of Pomposa Abbey in Codigoro, in the province of Ferrara (Italy), by means of the Non‐Smooth Contact Dynamics (NSCD) method. The main purpose of the work is to investigate the capacity of the main mechanical parameter used in the analyses, namely, the friction coefficient, to have effects on the mechanical response of ancient masonry structures undergoing seismic actions. Therefore, the tower was modelled following the discrete element method (DEM) and assembling the masonry texture as rigid bodies tied by frictional joints. Thus a discontinuous approach was used to assess the dynamic properties and the vulnerability of the masonry structure, through large deformations regulated by the Signorini's law, concerning the impenetrability between the rigid bodies; and by the Coulomb's law, regarding the dry‐friction model. Afterward, different values were assigned to the friction coefficient of the models, and a variety of real seismic shocks have been applied in the nonlinear analyses. Finally, it is possible to see different failure mechanisms resulting for each friction value and types of dynamic actions used, as expected.
A reconfigurable Bessel antenna for near‐field beam deflection
Authors: Lu Ping , Cheng Fei , Yang Yang , Zhang Bing , Huang Kama
Published: February 2020

This letter presents a reconfigurable leaky‐wave antenna for near‐field beam manipulation. The proposed antenna is based on a radial waveguide and a reconfigurable capacitive sheet, which is divided into four regions. To realize the reconfigurability, PIN diodes are electrically soldered to the gap between the adjacent patches in the upper surface except for the isolation zone, where no diodes are printed. By switching the states of PIN diodes in each region by turns, wavenumbers with two different azimuths are generated, thus the near‐field beam deflection can be achieved in different regions. By using the Genetic Algorithm, the PIN diodes are optimally deployed for realizing high antenna efficiency. The simulated (measured) results show that with the implementation of the reconfigurable capacitive sheet results in a near‐field beam scanning property. The beam deflection at a tilted angle of 17.4° (16.2°) can be achieved in different regions.
A two‐dimensional quasi‐optical system design method with low cross‐polarization based on Gaussian beam mode analysis
Authors: Chen Tianyang , Yao Yuan , Chen Xiaodong , Liu Xiaoming , Yu Junsheng
Published: February 2020

In the design of quasi‐optical systems, the cross‐polarization introduced by off‐axis mirrors is a major concern to us. By Gaussian beam mode analysis (GBMA), the electric field could be predicted precisely with this factor. In this study, we present some significant expressions and a method based on the energy of modes to analyze the influence of design parameters such as the distance between two objects and the incident angles of beams on the cross‐polarization level of a two‐dimensional (2D) multi‐reflector system with a feed containing cross‐polarization. Finally, combining these discussions, an innovative 2D quasi‐optical system design algorithm with low cross‐polarization based on the particle swarm optimization (PSO) algorithm is proposed considering various system variables. In order to verify the validity and accuracy of our method, we compare the results of our approach and physical optics (PO) in the commercial software package GRASP10 with the example of a double ellipsoidal mirror system.
Wideband slow phase loaded inductor‐composite right/left‐handed transmission line for compact UWB power divider
Authors: Daw Ahmed. F. , Abdalla Mahmoud A. , El‐Henawy Hadya
Published: February 2020

This article introduces analysis of the new configuration; inductor loaded left‐handed composite right‐/left‐handed transmission line ((L‐CRLH TL). Compared to conventional CRLH and dual CRLH, this configuration has the advantage of very slow phase (almost constant) and nonlinear propagation coefficient which enables it to be very effective in designing compact size and ultra‐wideband (UWB) microwave components. The theoretical and circuit model of the L‐CRLH TL is discussed. As an application, a compact UWB (3.1‐10.6 GHz) L‐CRLH power divider is designed using only one L‐CRLH cell with size of 2.7 × 8.6 mm2 whereas the whole power divider photoprint is 12.14 × 18.83 mm2. The size is 58.5% smaller compared to the conventional narrow band T‐junction power divider designed at the mid frequency. The results reveal good insertion losses (3.2 ± 0.2 dB for both S21 and S31), and good return losses (better than 10 dB within the passband).
Lanthanum phenylphosphonate–based multilayered coating for reducing flammability and smoke production of flexible polyurethane foam
Authors: Pan Ying , Cai Wei , Du Jia , Song Lei , Hu Yuan , Zhao Hongting
Published: February 2020

In the present work, lanthanum phenylphosphonate (LaPP)–based multilayered film was fabricated on the surface of flexible polyurethane (PU) foam by layer‐by‐layer self‐assembled method. The successful deposition of the coating was confirmed by scanning electron microscopy (SEM) and energy‐dispersive X‐ray (EDX). Subsequently, the thermal decomposition and burning behavior of untreated and treated PU foams were investigated by thermogravimetric analysis (TGA) and cone calorimeter, respectively. The TGA results indicated that Tmax2 of treated PU foams were increased by approximately 15°C to 20°C as compared with untreated PU foam. The peak heat release rate (PHRR) and total heat release (THR) of PU‐6 (with 19.5 wt% weight gain) were 188 kW/m2 and 20.3 MJ/m2, with reductions of 70% and 15% as compared with those of untreated PU foam, respectively. Meanwhile, the smoke production of treated PU foam was suppressed after the construction of LaPP‐based coating.
Tandem Molecular Dynamics and Continuum Studies of Shock‐Induced Pore Collapse in TATB
Authors: Zhao Puhan , Lee Sangyup , Sewell Tommy , Udaykumar H. S.
Published: February 2020

All‐atom molecular dynamics (MD) and Eulerian continuum simulations, performed using the LAMMPS and SCIMITAR3D codes, respectively, were used to study thermo‐mechanical aspects of the shock‐induced collapse of an initially cylindrical 50 nm diameter pore in single crystals of 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB). Three impact speeds, 0.5 km s−1, 1.0 km s−1 and 2.0 km s−1, were used to generate the shocks. These impact conditions are expected to yield collapse mechanisms ranging from predominantly visco‐plastic to hydrodynamic. For the MD studies, three crystal orientations (relative to shock‐propagation direction) were examined that span the limiting cases with respect to the crystalline anisotropy in TATB. An isotropic constitutive model was used for the continuum simulations, thus crystal anisotropy is absent. The evolution of spatiotemporally resolved quantities during collapse is reported including local pressure, temperature, pore size and shape, and material flow. Multiple models for the melting curve and specific heat were studied. Within the isotropic elastic/perfectly plastic continuum framework and for the range of impact conditions studied, the specific heat and melting curve sub‐models are shown to have modest effects on the continuum hotspot predictions in the present inert calculation. Treating the MD predictions as ‘ground truth’, albeit with a classical rather than quantum‐like heat capacity, it is clear that – at a minimum – an extension of the constitutive model to account for crystal plasticity and anisotropic strength will be required for a high‐fidelity continuum description.
ADN Recrystallization and Microencapsulation with HTPB by Simple Coacervation
Authors: de Oliveira Silva Jessica , Cardoso Kamila Pereira , Campos Silva Josiane Ribeiro , Kawachi Elizabete Yoshie , Nagamachi Márcio Yuji , de Araujo Ferrão Luiz Fernando
Published: February 2020

Ammonium dinitramide (ADN) has been considered the potential substitute for ammonium perchlorate in solid green propellants. However, it has also some drawbacks due to its high hygroscopicity and chemical incompatibility with some of the components present in composite propellant formulations. On the other hand, ADN melts at temperatures below degradation, which makes emulsion crystallization an important method to prepare spherical ADN particles that benefit both propellant slurry processing and casting. Spherical ADN particles were prepared by emulsion crystallization to be used for the microencapsulation studies, and whose method was assessed to better understand which parameters may affect the ADN particles formation. Microencapsulation protects ADN particles as it addresses hygroscopicity besides the given protection from chemical incompatibility. Polyurethane made of hydroxyl‐terminated polybutadiene was selected as a coating material because of its common use in propellants as a binder. Also, the good performance of methylene diphenyl diisocyanate as a curing agent was such that it was used in the whole study. The number of layers and the processing time played important roles in the formation of the capsule as seen in the impermeability tests. Besides, drying at 50 °C for 168 h showed to be even more beneficial on average for the capsule protective property. Chemical compatibility between the capsule and ADN was confirmed at 60 °C which allows it to be used as a protective coating. However, the obtained average coating thickness of ten microns has to be reduced yet with more efficient protective coating materials.
Complex index assessment of operator's reliability in the control room
Authors: Stojiljkovic Evica , Bijelic Bojan , Haznadarevic Lutvo , Savic Suzana , Grozdanovic Miroljub
Published: February 2020

Operator's reliability in control room (CR) is largely influenced by the design of CR elements (control desk, display panel), compliance between the operator and these elements and influence of work environment on operator's work. Therefore, the methodological approach described in this paper was based on multidisciplinary research of human factors (operator's information processing task, motoric and logical task, human error, monotony, overload, stress); workplace (adjustment of workplace to anthropometrical and physiological characteristics of the operator), and indoor environment factors (illumination, brightness, noise level, air temperature, relative humidity, and air velocity). By using results of this research, we determined the values and positions of indicators of operator's reliability in the CR for monitoring and control of soybean oil hexane extraction process in Bioprotein factory. These indicators are then ranked by importance using the paired comparison method. Finally, a complex index of operator's reliability was determined. The index represents the degree of operator's suitability for the performance of a specific task. This research determines quantitative parameters for evaluating the reliability of operator's activities in CR. Those parameters could be used to detect omissions in operator's activities influenced by inadequate ergonomic design of CR elements and negative impacts of a CR environment.
Increase of γ‐Fe2O3/CNT composite quantum capacitance by structural design for performance optimization of electrode materials
Authors: Shunaev Vladislav V. , Ushakov Arseni V. , Glukhova Olga E.
Published: February 2020

Performance optimization of electrode materials for lithium‐ion batteries is one the most important scientific problems. In this paper, we suggest structural design of γ‐Fe2O3/CNT composite for increase of its quantum capacitance that is required by modern energy storage devices capable of quick transfer or accumulation of energy and ensuring long‐term autonomous operation. For this goal, we investigate the specific quantum capacitance of the γ‐Fe2O3/CNT composites with a different content of maghemite by quantum chemical methods. The content of maghemite is varied by length of CNTs as well as by number of γ‐Fe2O3 unit cell the weight ratio equals 13.71%, 20.74%, 26.69%, and 34.30%. It is found that the quantum capacitance grows with increasing maghemite concentration. Calculations show that the value of QC at the Fermi level for γ‐Fe2O3/CNT is correlated with the theoretical specific capacity of the material. Proposed in this work approach to calculating the quantum capacitance with further analysis of its dependence on voltage can be an effective tool for optimizing the content of the composite with the aim of balancing the Faradaic and non‐Faradaic component of its functional activity.
Eclectic flavor groups
Authors: Nilles Hans Peter , Ramos-Sánchez Saúl , Vaudrevange Patrick K. S.
Published: February 2020

Abstract

The simultaneous study of top-down and bottom-up approaches to modular flavor symmetry leads necessarily to the concept of eclectic flavor groups. These are non-trivial products of modular and traditional flavor symmetries that exhibit the phenomenon of local flavor enhancement in moduli space. We develop methods to determine the eclectic flavor groups that can be consistently associated with a given traditional flavor symmetry. Applying these methods to a large family of prominent traditional flavor symmetries, we try to identify potential candidates for realistic eclectic flavor groups and show that they are relatively rare. Model building with finite modular flavor symmetries thus appears to be much more restrictive than previously thought.
Prediction of survival in patients with IDH-wildtype astrocytic gliomas using dynamic O-(2-[18F]-fluoroethyl)-l-tyrosine PET
Authors: Bauer Elena K. , Stoffels Gabriele , Blau Tobias , Reifenberger Guido , Felsberg Jörg , Werner Jan M. , Lohmann Philipp , Rosen Jurij , Ceccon Garry , Tscherpel Caroline , Rapp Marion , Sabel Michael , Filss Christian P. , Shah Nadim J. , Neumaier Bernd , Fink Gereon R. , Langen Karl-Josef , Galldiks Norbert
Published: February 2020

Purpose

Integrated histomolecular diagnostics of gliomas according to the World Health Organization (WHO) classification of 2016 has refined diagnostic accuracy and prediction of prognosis. This study aimed at exploring the prognostic value of dynamic O-(2-[18F]-fluoroethyl)-l-tyrosine (FET) PET in newly diagnosed, histomolecularly classified astrocytic gliomas of WHO grades III or IV.

Methods

Before initiation of treatment, dynamic FET PET imaging was performed in patients with newly diagnosed glioblastoma (GBM) and anaplastic astrocytoma (AA). Static FET PET parameters such as maximum and mean tumour/brain ratios (TBRmax/mean), the metabolic tumour volume (MTV) as well as the dynamic FET PET parameters time-to-peak (TTP) and slope, were obtained. The predictive ability of FET PET parameters was evaluated concerning the progression-free and overall survival (PFS, OS). Using ROC analyses, threshold values for FET PET parameters were obtained. Subsequently, univariate Kaplan-Meier and multivariate Cox regression survival analyses were performed to assess the predictive power of these parameters for survival.

Results

Sixty patients (45 GBM and 15 AA patients) of two university centres were retrospectively identified. Patients with isocitrate dehydrogenase (IDH)-mutant or O6-methylguanine-DNA-methyltransferase (MGMT) promoter-methylated tumours had a significantly longer PFS and OS (both P < 0.001). Furthermore, ROC analysis of IDH-wildtype glioma patients (n = 45) revealed that a TTP > 25 min (AUC, 0.90; sensitivity, 90%; specificity, 87%; P < 0.001) was highly prognostic for longer PFS (13 vs. 7 months; P = 0.005) and OS (29 vs. 12 months; P < 0.001). In contrast, at a lower level of significance, TBRmax, TBRmean, and MTV were only prognostic for longer OS (P = 0.004, P = 0.038, and P = 0.048, respectively). Besides complete resection and a methylated MGMT promoter, TTP remained significant in multivariate survival analysis (all P ≤ 0.02), indicating an independent predictor for OS.

Conclusions

Our data suggest that dynamic FET PET allows the identification of patients with longer OS among patients with newly diagnosed IDH-wildtype GBM and AA.
Drag Reduction and Energy Saving by Spanwise Traveling Transversal Surface Waves for Flat Plate Flow
Authors: Albers Marian , Meysonnat Pascal S. , Fernex Daniel , Semaan Richard , Noack Bernd R. , Schröder Wolfgang
Published: February 2020

Wall-resolved large-eddy simulations are performed to study the impact of spanwise traveling transversal surface waves in zero-pressure gradient turbulent boundary layer flow.
Eighty variations of wavelength, period, and amplitude of the space- and time-dependent sinusoidal wall motion are considered for a boundary layer at a momentum thickness based Reynolds number of $${\rm Re}_\theta = 1000$$Reθ=1000. The results show a strong decrease of friction drag of up to $$26\%$$26% and considerable net power saving of up to $$10\%$$10%. However, the highest net power saving does not occur at the maximum drag reduction. The drag reduction is modeled as a function of the actuation parameters by support vector regression using the LES data.
A dependence of the spanwise pressure drag on the wavelength is found. A substantial attenuation of the near-wall turbulence intensity and especially a weakening of the near-wall velocity streaks are observed. Similarities between the current actuation technique and the method of a spanwise oscillating wall without any normal surface deflection are reported. In particular, the generation of a directional spanwise oscillating Stokes layer is found to be related to skin-friction reduction.
Error estimates for the finite element approximation of bilinear boundary control problems
Authors: Winkler Max
Published: February 2020

In this article a special class of nonlinear optimal control problems involving a bilinear term in the boundary condition is studied. These kind of problems arise for instance in the identification of an unknown space-dependent Robin coefficient from a given measurement of the state, or when the Robin coefficient can be controlled in order to reach a desired state. Necessary and sufficient optimality conditions are derived and several discretization approaches for the numerical solution of the optimal control problem are investigated. Considered are both a full discretization and the postprocessing approach meaning that we compute an improved control by a pointwise evaluation of the first-order optimality condition. For both approaches finite element error estimates are shown and the validity of these results is confirmed by numerical experiments.
Evaluating the Role of Autistic Traits, Social Anxiety, and Social Network Changes During Transition to First Year of University in Typically Developing Students and Students on the Autism Spectrum
Authors: Lei Jiedi , Brosnan Mark , Ashwin Chris , Russell Ailsa
Published: February 2020

This is the first longitudinal study to quantitatively evaluate changes in social network structure (SNS) and perceived social support (PSS) amongst first-year students on the autism spectrum (n = 21) and typically developing (TD; n = 182) students transitioning to university. The relative impact of changes in SNS/PSS, students’ social anxiety and autistic traits, on first-year university transition outcomes were also examined. Both groups gained friends over time who provided better support quantity and quality during first year of university. Social anxiety showed long-term differential negative impact on students on the autism spectrum and TD students’ academic, social and personal/emotional adjustments, and institutional attachment, suggesting stakeholders should focus on delivering interventions to reduce social anxiety to improve university transition outcomes.
A Fair Governance: On Inequality, Power and Democracy
Authors: Barucca Paolo
Published: February 2020

Can governments keep the pace of global markets? It is a defining characteristic of the present times, tested and measured within multiple studies, that we are living in an increasingly interconnected economy in which giant companies emerge and compete presenting new goods and products at a global scale. The competing environment of international markets produces quickly growing creatures that old nation-states struggle to understand, monitor and, consequently, regulate. In this regard, the selection process taking place in the market seems to be far more effective and greedy than the selection process we apply to our governments. In this paper I discuss the basic theoretical mechanisms for the persistence of wealth concentration, introducing a general game-theoretical framework to connect governance, market economy, and wealth distribution, and to rethink democracy and fairness in policy-making, especially with the aim of global sustainability governance.
The Intonation of Information-Seeking and Rhetorical Questions in Icelandic
Authors: Dehé Nicole , Braun Bettina
Published: February 2020

We investigate the intonation of information-seeking and rhetorical questions in Icelandic. The results for the information-seeking questions largely confirm observations in previous literature based mostly on introspective data: Polar questions are mostly realized with late rise nuclear accents where the peak aligns after a stressed syllable (L*+H),wh-questions with peak accents (H*);wh-questions often start high (%H, H*). Illocution types (that is, information-seeking versus rhetorical questions) differ in nuclear pitch accent types and in the type and frequency of prenuclear accents. The default boundary tone is low (L%) across question types and illocution types. The results are discussed against the background of previous findings with respect to the relationship between question and illocution type, and prosody.*
IS “RACE” MODERN?
Authors: Hochman Adam
Published: February 2020

Race theorists have been unable to reach a consensus regarding the basic historical question, “is ‘race’ modern?” I argue that this is partly because the question itself is ambiguous. There is not really one question that race scholars are answering, but at least six. First, is theconcept of racemodern? Second, is there a modern concept of race that isdistinct from earlier race concepts? Third, are“races” themselvesmodern? Fourth, areracialized groupsmodern? Fifth, are themeans and methods associated with racializationmodern? And sixth, are themeanings attached to racialized traitsmodern? Because these questions have different answers, the debate about the historical origins of “race” cannot be resolved unless they are distinguished. I will explain the ways in which “race” is and is not modern by answering these questions, thereby offering a resolution to a seemingly intractable problem.
A Spatially Explicit, Empirical Estimate of Tree‐Based Biological Nitrogen Fixation in Forests of the United States
Authors: Staccone Anika , Liao Wenying , Perakis Steven , Compton Jana , Clark Christopher M. , Menge Duncan
Published: February 2020

Quantifying human impacts on the nitrogen (N) cycle and investigating natural ecosystem N cycling depend on the magnitude of inputs from natural biological nitrogen fixation (BNF). Here, we present two bottom‐up approaches to quantify tree‐based symbiotic BNF based on forest inventory data across the coterminous United States and SE Alaska. For all major N‐fixing tree genera, we quantify BNF inputs using (1) ecosystem N accretion rates (kg N ha−1yr−1) scaled with spatial data on tree abundance and (2) percent of N derived from fixation (%Ndfa) scaled with tree N demand (from tree growth rates and stoichiometry). We estimate that trees fix 0.30–0.88 Tg N yr−1across the study area (1.4–3.4 kg N ha−1yr−1). Tree‐based N fixation displays distinct spatial variation that is dominated by two genera,Robinia(64% of tree‐associated BNF) andAlnus(24%). The third most important genus,Prosopis, accounted for 5%. Compared to published estimates of other N fluxes, tree‐associated BNF accounted for 0.59 Tg N yr−1, similar to asymbiotic (0.37 Tg N yr−1) and understory symbiotic BNF (0.48 Tg N yr−1), while N deposition contributed 1.68 Tg N yr−1and rock weathering 0.37 Tg N yr−1. Overall, our results reveal previously uncharacterized spatial patterns in tree BNF that can inform large‐scale N assessments and serve as a model for improving tree‐based BNF estimates worldwide. This updated, lower BNF estimate indicates a greater ratio of anthropogenic to natural N inputs, suggesting an even greater human impact on the N cycle.
Sensitivity of the Latitude of the Westerly Jet Stream to Climate Forcing
Authors: Chen Gang , Zhang Pengfei , Lu Jian
Published: February 2020

The latitude of the westerly jet stream is influenced by a variety of climate forcings, but their effects on the jet latitude often manifest as a tug of war between tropical forcing (e.g., tropical upper‐tropospheric warming) and polar forcing (e.g., Antarctic stratospheric cooling or Arctic amplification). Here we present a unified forcing‐feedback framework relating different climate forcings to their forced jet changes, in which the interactions between the westerly jet and synoptic eddies are synthesized by a zonal advection feedback, analogous to the feedback framework for assessing climate sensitivity. This framework is supported by a prototype feedback analysis in the atmospheric dynamical core of a climate model with diverse thermal and mechanical forcings. Our analysis indicates that the latitude of a westerly jet is most sensitive to the climate change‐induced jet speed changes near the tropopause. The equatorward jet shift also displays a larger deviation from linearity than the poleward counterpart.
SAMI3 Simulations of Ionospheric Metallic Layers at Arecibo
Authors: Krall J. , Huba J. D. , Nossa E. , Aponte N. , Drob D. P.
Published: February 2020

The Naval Research Laboratory Sami3 is Also a Model of the Ionosphere (SAMI3) ionosphere/plasmasphere code is used to examine the physics of metallic layers at altitudes from 80 to 160 km. Results are presented near the simulated location of the Arecibo observatory (18°N, 66°W). We find that simulations, using winds from the empirical horizontal wind model, produce layers consistent with those observed at Arecibo. Specifically, we find upper semidiurnal and lower diurnal traces similar to those identified in previous observational surveys. While metallic layers are shaped by meridional winds, zonal winds, and electric fields, much of the observed structure is produced if only meridional wind forces are included in the model. Stratification below 110 km, where the ions are very weakly magnetized, is supported mainly by meridional wind shear.
Implementation of U.K. Earth System Models for CMIP6
Authors: Sellar Alistair A. , Walton Jeremy , Jones Colin G. , Wood Richard , Abraham Nathan Luke , Andrejczuk Miroslaw , Andrews Martin B. , Andrews Timothy , Archibald Alex T. , de Mora Lee , Dyson Harold , Elkington Mark , Ellis Richard , Florek Piotr , Good Peter , Gohar Laila , Haddad Stephen , Hardiman Steven C. , Hogan Emma , Iwi Alan , Jones Christopher D. , Johnson Ben , Kelley Douglas I. , Kettleborough Jamie , Knight Jeff R. , Köhler Marcus O. , Kuhlbrodt Till , Liddicoat Spencer , Linova‐Pavlova Irina , Mizielinski Matthew S. , Morgenstern Olaf , Mulcahy Jane , Neininger Erica , O'Connor Fiona M. , Petrie Ruth , Ridley Jeff , Rioual Jean‐Christophe , Roberts Malcolm , Robertson Eddy , Rumbold Steven , Seddon Jon , Shepherd Harry , Shim Sungbo , Stephens Ag , Teixiera Joao C. , Tang Yongming , Williams Jonny , Wiltshire Andy , Griffiths Paul T.
Published: February 2020

We describe the scientific and technical implementation of two models for a core set of experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6). The models used are the physical atmosphere‐land‐ocean‐sea ice model HadGEM3‐GC3.1 and the Earth system model UKESM1 which adds a carbon‐nitrogen cycle and atmospheric chemistry to HadGEM3‐GC3.1. The model results are constrained by the external boundary conditions (forcing data) and initial conditions. We outline the scientific rationale and assumptions made in specifying these. Notable details of the implementation include an ozone redistribution scheme for prescribed ozone simulations (HadGEM3‐GC3.1) to avoid inconsistencies with the model's thermal tropopause, and land use change in dynamic vegetation simulations (UKESM1) whose influence will be subject to potential biases in the simulation of background natural vegetation. We discuss the implications of these decisions for interpretation of the simulation results. These simulations are expensive in terms of human and CPU resources and will underpin many further experiments; we describe some of the technical steps taken to ensure their scientific robustness and reproducibility.
The ACSL3-LPIAT1 signaling drives prostaglandin synthesis in non-small cell lung cancer
Authors: Saliakoura Maria , Reynoso-Moreno Inés , Pozzato Chiara , Rossi Sebastiano Matteo , Galié Mirco , Gertsch Jürg , Konstantinidou Georgia
Published: February 2020

Enhanced prostaglandin production promotes the development and progression of cancer. Prostaglandins are generated from arachidonic acid (AA) by the action of cyclooxygenase (COX) isoenzymes. However, how cancer cells are able to maintain an elevated supply of AA for prostaglandin production remains unclear. Here, by using lung cancer cell lines and clinically relevant KrasG12D-driven mouse models, we show that the long-chain acyl-CoA synthetase (ACSL3) channels AA into phosphatidylinositols to provide the lysophosphatidylinositol-acyltransferase 1 (LPIAT1) with a pool of AA to sustain high prostaglandin synthesis. LPIAT1 knockdown suppresses proliferation and anchorage-independent growth of lung cancer cell lines, and hinders in vivo tumorigenesis. In primary human lung tumors, the expression ofLPIAT1is elevated compared with healthy tissue, and predicts poor patient survival. This study uncovers the ACSL3-LPIAT1 axis as a requirement for the sustained prostaglandin synthesis in lung cancer with potential therapeutic value.
Spaceflight associated neuro-ocular syndrome (SANS) and the neuro-ophthalmologic effects of microgravity: a review and an update
Authors: Lee Andrew G. , Mader Thomas H. , Gibson C. Robert , Tarver William , Rabiei Pejman , Riascos Roy F. , Galdamez Laura A. , Brunstetter Tyson
Published: February 2020

Prolonged microgravity exposure during long-duration spaceflight (LDSF) produces unusual physiologic and pathologic neuro-ophthalmic findings in astronauts. These microgravity associated findings collectively define the “Spaceflight Associated Neuro-ocular Syndrome” (SANS). We compare and contrast prior published work on SANS by the National Aeronautics and Space Administration’s (NASA) Space Medicine Operations Division with retrospective and prospective studies from other research groups. In this manuscript, we update and review the clinical manifestations of SANS including: unilateral and bilateral optic disc edema, globe flattening, choroidal and retinal folds, hyperopic refractive error shifts, and focal areas of ischemic retina (i.e., cotton wool spots). We also discuss the knowledge gaps for in-flight and terrestrial human research including potential countermeasures for future study. We recommend that NASA and its research partners continue to study SANS in preparation for future longer duration manned space missions.
Weighted persistent homology for biomolecular data analysis
Authors: Meng Zhenyu , Anand D. Vijay , Lu Yunpeng , Wu Jie , Xia Kelin
Published: February 2020

In this paper, we systematically review weighted persistent homology (WPH) models and their applications in biomolecular data analysis. Essentially, the weight value, which reflects physical, chemical and biological properties, can be assigned to vertices (atom centers), edges (bonds), or higher order simplexes (cluster of atoms), depending on the biomolecular structure, function, and dynamics properties. Further, we propose the first localized weighted persistent homology (LWPH). Inspired by the great success of element specific persistent homology (ESPH), we do not treat biomolecules as an inseparable system like all previous weighted models, instead we decompose them into a series of local domains, which may be overlapped with each other. The general persistent homology or weighted persistent homology analysis is then applied on each of these local domains. In this way, functional properties, that are embedded in local structures, can be revealed. Our model has been applied to systematically study DNA structures. It has been found that our LWPH based features can be used to successfully discriminate the A-, B-, and Z-types of DNA. More importantly, our LWPH based principal component analysis (PCA) model can identify two configurational states of DNA structures in ion liquid environment, which can be revealed only by the complicated helical coordinate system. The great consistence with the helical-coordinate model demonstrates that our model captures local structure variations so well that it is comparable with geometric models. Moreover, geometric measurements are usually defined in local regions. For instance, the helical-coordinate system is limited to one or two basepairs. However, our LWPH can quantitatively characterize structure information in regions or domains with arbitrary sizes and shapes, where traditional geometrical measurements fail.
HIV-1 Vaccine Sequences Impact V1V2 Antibody Responses: A Comparison of Two Poxvirus Prime gp120 Boost Vaccine Regimens
Authors: Shen Xiaoying , Laher Fatima , Moodie Zoe , McMillan Arthur S. , Spreng Rachel L. , Gilbert Peter B. , Huang Ying , Yates Nicole L. , Grunenberg Nicole , Juliana McElrath M. , Allen Mary , Pensiero Michael , Mehra Vijay L. , Der Meeren Olivier Van , Barnett Susan W. , Phogat Sanjay , Gray Glenda E. , Bekker Linda-Gail , Corey Lawrence , Tomaras Georgia D.
Published: February 2020

In the RV144 trial, vaccine-induced V1V2 IgG correlated with decreased HIV-1 risk. We investigated circulating antibody specificities in two phase 1 poxvirus prime-protein boost clinical trials conducted in South Africa: HVTN 097 (subtype B/E) and HVTN 100 (subtype C). With cross-subtype peptide microarrays and multiplex binding assays, we probed the magnitude and breadth of circulating antibody responses to linear variable loop 2 (V2) and conformational V1V2 specificities. Antibodies targeting the linear V2 epitope, a correlate of decreased HIV-1 risk in RV144, were elicited up to 100% and 61% in HVTN 097 and HVTN 100, respectively. Despite higher magnitude of envelope-specific responses in HVTN 100 compared to HVTN 097 (p’s < 0.001), the magnitude and positivity for V2 linear epitope and V1V2 proteins were significantly lower in HVTN 100 compared to HVTN 097. Meanwhile, responses to other major linear epitopes including the variable 3 (V3) and constant 5 (C5) epitopes were higher in HVTN 100 compared to HVTN 097. Our data reveal substantial differences in the circulating antibody specificities induced by vaccination in these two canarypox prime-protein boost trials. Our findings suggest that the choice of viral sequences in prime-boost vaccine regimens, and potentially adjuvants and immunogen dose, influence the elicitation of V2-specific antibodies.
QTL mapping of modelled metabolic fluxes reveals gene variants impacting yeast central carbon metabolism
Authors: Eder Matthias , Nidelet Thibault , Sanchez Isabelle , Camarasa Carole , Legras Jean-Luc , Dequin Sylvie
Published: February 2020

The yeast Saccharomyces cerevisiae is an attractive industrial microorganism for the production of foods and beverages as well as for various bulk and fine chemicals, such as biofuels or fragrances. Building blocks for these biosyntheses are intermediates of yeast central carbon metabolism (CCM), whose intracellular availability depends on balanced single reactions that form metabolic fluxes. Therefore, efficient product biosynthesis is influenced by the distribution of these fluxes. We recently demonstrated great variations in CCM fluxes between yeast strains of different origins. However, we have limited understanding of flux modulation and the genetic basis of flux variations. In this study, we investigated the potential of quantitative trait locus (QTL) mapping to elucidate genetic variations responsible for differences in metabolic flux distributions (fQTL). Intracellular metabolic fluxes were estimated by constraint-based modelling and used as quantitative phenotypes, and differences in fluxes were linked to genomic variations. Using this approach, we detected four fQTLs that influence metabolic pathways. The molecular dissection of these QTLs revealed two allelic gene variants, PDB1 and VID30, contributing to flux distribution. The elucidation of genetic determinants influencing metabolic fluxes, as reported here for the first time, creates new opportunities for the development of strains with optimized metabolite profiles for various applications.
Effect of immediate cold formalin fixation on phosphoprotein IHC tumor biomarker signal in liver tumors using a cold transport device
Authors: Lerch Melissa L. , Kenerson Heidi L. , Chafin David , Westerhoff Maria , Theiss Abbey , Otter Michael , Yeung Raymond S. , Baird Geoffrey S.
Published: February 2020

Phosphoproteins are the key indicators of signaling network pathway activation. Many disease treatment therapies are designed to inhibit these pathways and effective diagnostics are required to evaluate the efficacy of these treatments. Phosphoprotein IHC have been impractical for diagnostics due to inconsistent results occurring from technical limitations. We have designed and tested a novel cold transport device and rapid cold plus warm formalin fixation protocol using phosphoproteins IHC. We collected 50 liver tumors that were split into two experimental conditions: 2 + 2 rapid fixation (2 hours cold then 2 hour warm formalin) or 4 hour room-temperature formalin. We analyzed primary hepatocellular carcinoma (n = 10) and metastatic gastrointestinal tumors (n = 28) for phosphoprotein IHC markers pAKT, pERK, pSRC, pSTAT3, and pSMAD2 and compared them to slides obtained from the clinical blocks. Expression of pERK and pSRC, present in the metastatic colorectal carcinoma, were better preserved with the rapid processing protocol while pSTAT3 expression was detected in hepatocellular carcinoma. Differences in pSMAD2 expression were difficult to detect due to the ubiquitous nature of protein expression. There were only 3 cases expressing pAKT and all exhibited a dramatic loss of signal for the standard clinical workflow. The rapid cold preservation shows improvement in phosphoprotein preservation.
A massacre of early Neolithic farmers in the high Pyrenees at Els Trocs, Spain
Authors: Alt Kurt W. , Tejedor Rodríguez Cristina , Nicklisch Nicole , Roth David , Szécsényi Nagy Anna , Knipper Corina , Lindauer Susanne , Held Petra , de Lagrán Íñigo García Martínez , Schulz Georg , Schuerch Thomas , Thieringer Florian , Brantner Philipp , Brandt Guido , Israel Nicole , Arcusa Magallón Héctor , Meyer Christian , Mende Balazs G. , Enzmann Frieder , Dresely Veit , Ramsthaler Frank , Guillén José Ignacio Royo , Scheurer Eva , López Montalvo Esther , Garrido Pena Rafael , Pichler Sandra L. , Guerra Manuel A. Rojo
Published: February 2020

Violence seems deeply rooted in human nature and an endemic potential for such is today frequently associated with differing ethnic, religious or socio-economic backgrounds. Ethnic nepotism is believed to be one of the main causes of inter-group violence in multi-ethnic societies. At the site of Els Trocs in the Spanish Pyrenees, rivalling groups of either migrating early farmers or farmers and indigenous hunter-gatherers collided violently around 5300 BCE. This clash apparently resulted in a massacre of the Els Trocs farmers. The overkill reaction was possibly triggered by xenophobia or massive disputes over resources or privileges. In the present, violence and xenophobia are controlled and sanctioned through social codes of conduct and institutions. So that, rather than representing an insurmountable evolutionary inheritance, violence and ethnic nepotism can be overcome and a sustainable future achieved through mutual respect, tolerance and openness to multi-ethnic societies.
Mapping patterns of abiotic and biotic stress resilience uncovers conservation gaps and breeding potential of Vigna wild relatives
Authors: van Zonneveld Maarten , Rakha Mohamed , Tan Shin yee , Chou Yu-Yu , Chang Ching-Huan , Yen Jo-Yi , Schafleitner Roland , Nair Ramakrishnan , Naito Ken , Solberg Svein Ø.
Published: February 2020

This study provides insights in patterns of distribution of abiotic and biotic stress resilience across Vigna gene pools to enhance the use and conservation of these genetic resources for legume breeding. Vigna is a pantropical genus with more than 88 taxa including important crops such as V. radiata (mung bean) and V. unguiculata (cowpea). Our results show that sources of pest and disease resistance occur in at least 75 percent of the Vigna taxa, which were part of screening assessments, while sources of abiotic stress resilience occur in less than 30 percent of screened taxa. This difference in levels of resilience suggests that Vigna taxa co-evolve with pests and diseases while taxa are more conservative to adapt to climatic changes and salinization. Twenty-two Vigna taxa are poorly conserved in genebanks or not at all. This germplasm is not available for legume breeding and requires urgent germplasm collecting before these taxa extirpate on farm and in the wild. Vigna taxa, which tolerate heat and drought stress are rare compared with taxa, which escape these stresses because of short growing seasons or with taxa, which tolerate salinity. We recommend prioritizing these rare Vigna taxa for conservation and screening for combined abiotic and biotic stress resilience resulting from stacked or multifunctional traits. The high presence of salinity tolerance compared with drought stress tolerance, suggests that Vigna taxa are good at developing salt-tolerant traits. Vigna taxa are therefore of high value for legume production in areas that will suffer from salinization under global climate change.