bluuebunny/crossref_metadata_2025 huggingface dataset:
Toward narrowing the gap between science communication and science education disciplines
Authors: Kohen Zehavit , Dori Yehudit J.
Published: November 2018

Science communication and science education aim to expose citizens to scientific knowledge, which is increasingly becoming a prerequisite for effective participation in modern society. We aim to present a review of science communication and science education literature, for highlighting the need for and importance of narrowing the gap between the two communities. Our objective was to find what themes, if any, are common to the two disciplines, based on keyword searches of the literature, that represent overlap constructs between the two communities. We searched for academic articles published from 2000 to 2017 in three science communication journals and three science education journals, which contained the keywords science communication, science engagement and science understanding. A three‐stage literature review yielded 70 papers that provided the basis for common theme identification: (i) attitudes towards the importance of science communication, (ii) communication channel types and (iii) scientific knowledge construction. Findings reveal similarities and disparities between the two communities and the stakeholders they investigated. Both communities agree on the meaning of process and product science communication constructs. Yet, while the science education community mainly relates to the product construct, the science communication community mainly relays to the communication construct. We then discuss the value of fostering dialogue between the two communities. Our research contributes to raising the awareness of the value of maintaining ongoing dialogue between science communication and science education communities, accounting for the three common themes we have identified, implying that a common language is emerging, and the variety of stakeholders involved.
Theoretical Study on the Catalytic Oxidation of p‐Iodophenol by Horseradish Peroxidase in a Chemiluminescent System
Authors: Liu Jian , Lai Jiahui , Qi Liguo , Liu Xiumei , Zhang Lili , Li Yibin
Published: November 2018

Oxidation of p‐iodophenol (PIP) by horseradish peroxidase (HRP) is a key factor contributing to the enhancement effect of PIP in the luminol‐HRP‐H2O2 chemiluminescent (CL) system. However, the mechanism of enhancement is still unproved to this day. Herein we use quantum mechanics (QM) calculations to study the process of PIP oxidation by HRP, compound I (HRP−I) and compound II (HRP‐II), and try to uncover the enhancement mechanism. The calculations demonstrate that the oxidation process of PIP by HRP−I/HRP‐II involve a proton‐coupled electron‐transfer step and reveal the crucial role of a bridging water molecule. Besides, the reaction of HRP with PIP shows remarkably lower barriers in comparison with the reaction with luminol. This suggests that the enhancer PIP accelerates the turnover of HRP enzyme, which may facilitate the enhancement effect of PIP in the luminol CL system.
Synthesis of Benzimidazoles via Domino Intra and Intermolecular C‐N Cross‐Coupling Reaction
Authors: Kondraganti Lakshmi , Manabolu Surendra babu , Dittakavi Ramachandran
Published: November 2018

The synthesis of aminobenzimidazoles has been demonstrated under mild reaction conditions using cobalt catalyst in one pot reaction. This methodology involved domino intra and intermolecular C‐N cross‐coupling reaction. In addition, functional group tolerance has been also explored.
Bending behavior of high‐performance, micro‐reinforced concrete
Authors: Busse Daniel , Empelmann Martin
Published: November 2018

The development of high‐performance concretes enables a reduction of the dimensions of concrete members. If these dimensions are reduced down to the size of 30–50 mm, a conventional reinforcement cannot be used and alternative concepts are required. In this case, micro‐reinforced concrete, internationally also known as ferro‐cement, can be used advantageously. In this paper, results of bending tests on micro‐reinforced beams made of high and ultra‐high performance concrete with varying micro‐reinforcement ratios and orientations are presented. Furthermore, approaches based on DIN EN 1992‐1‐1 (EC 2), allowing the determination of a minimum micro‐reinforcement ratio as well as the secure assessment of the ultimate flexural strength of micro‐reinforced beams were developed based on the test results. In addition, a finite element analysis of the beams is shown, enabling a precise recalculation of the load‐bearing behavior as well as the ultimate flexural strengths obtained during the tests. Overall, the described experimental and theoretical investigations are a valuable contribution towards the development of a general design approach for thin‐walled, micro‐reinforced concrete members.
The LHC potential of vector-like quark doublets
Authors: Cacciapaglia Giacomo , Deandrea Aldo , Gaur Naveen , Harada Daisuke , Okada Yasuhiro , Panizzi Luca
Published: November 2018

Abstract

The existence of new vector-like quarks is often predicted by models of new physics beyond the Standard Model, and the development of discovery strategies at colliders is the object of an intense effort from the high-energy community. Our analysis aims at identifying the constraints on and peculiar signatures of simplified scenarios containing two vector-like quark doublets mixing with any of the SM quark generations. This scenario is a necessary ingredient of a broad class of theoretically motivated constructions. We focus on the two charge 2/3 states t
1,2
′
that, due to their peculiar mixing patterns, feature new production and decay modes that are not searched for at the LHC: single production of the heavier state can dominate over the light one, while pair production via electroweak interactions overcomes the QCD one for masses at the TeV scale.
Transverse-momentum resummation for top-quark pair production at the LHC
Authors: Catani Stefano , Grazzini Massimiliano , Sargsyan Hayk
Published: November 2018

Abstract

We consider transverse-momentum resummation for top-quark pair production in hadron collisions. At small transverse momenta of the top-quark pair, the logarithmically-enhanced QCD contributions are resummed to all orders up to next-to-leading logarithmic accuracy. At intermediate and large values of transverse momenta, the resummation is consistently combined with the complete result at fixed perturbative order. We present numerical results for the transverse-momentum distribution of top-quark pairs at LHC energies. We perform a detailed study of the scale dependence of the results to estimate their perturbative uncertainty. We comment on the comparison with ATLAS and CMS data.
A Qualitative Comparative Analysis (QCA) of Satisfaction toward Extreme Sporting Events
Authors: Scarpi Daniele , Pizzi Gabriele , Raggiotto Francesco , Mason Michela
Published: November 2018

We examine participant satisfaction in the context of extreme sporting events, where participants seek intense sensations but want to feel in control over the risky challenges. We combine two streams of literature scarcely related by previous studies, addressing both event-related and psychological attributes of extreme individuals. Because of the complex set of inter-relationships in which the investigated phenomena unfold, complexity theory tenets can provide a more accurate understanding of what generates extreme sport participants’ satisfaction toward a sporting event. Applying this perspective, the present research determines the possible combinations that build strong participant satisfaction in the context of extreme sporting events. Through qualitative comparative analysis (QCA), we identify more possible “recipes” that contribute to high levels of satisfaction. Results suggest that attributes related to the event (trust, image, attitude) and attributes related to the psychology of extreme sport participants (sensation-seeking, perceived control) contribute jointly in all “recipes”. Furthermore, satisfaction can emerge for events despite low attitude if their image is strong and participants feel in control of the challenges.
Learnings about the complexity of extracellular tau aid development of a blood‐based screen for Alzheimer's disease
Authors: Chen Zhicheng , Mengel David , Keshavan Ashvini , Rissman Robert A. , Billinton Andrew , Perkinton Michael , Percival‐Alwyn Jennifer , Schultz Aaron , Properzi Michael , Johnson Keith , Selkoe Dennis J. , Sperling Reisa A. , Patel Purvish , Zetterberg Henrik , Galasko Douglas , Schott Jonathan M. , Walsh Dominic M.
Published: November 2018

Introduction

The tau protein plays a central role in Alzheimer's disease (AD), and there is huge interest in measuring tau in blood and cerebrospinal fluid (CSF).

Methods

We developed a set of immunoassays to measure tau in specimens from humans diagnosed based on current best clinical and CSF biomarker criteria.

Results

In CSF, mid‐region‐ and N‐terminal‐detected tau predominated and rose in disease. In plasma, an N‐terminal assay (NT1) detected elevated levels of tau in AD and AD‐mild cognitive impairment (MCI). Plasma NT1 measurements separated controls from AD‐MCI (area under the curve [AUC] = 0.88) and AD (AUC = 0.96) in a discovery cohort and in a Validation Cohort (with AUCs = 0.79 and 0.75, respectively).

Discussion

The forms of tau in CSF and plasma are distinct, but in each specimen type, the levels of certain fragments are increased in AD. Measurement of plasma NT1 tau should be aggressively pursued as a potential blood‐based screening test for AD/AD‐MCI.
Concurrent Assessment of Penile Blood Flow and Circumference as Indicators of Male Sexual Arousal
Authors: Bossio Jennifer A. , Singh Manya , Pukall Caroline F.
Published: November 2018

Introduction

The current study aims to validate a new imaging tool to assess men’s sexual psychophysiological responding: laser Doppler imaging (LDI), which directly measures subcutaneous genital blood flow. In this study, we concurrently assessed genital sexual arousal in a sample of men using the LDI and the current gold standard of male sexual psychophysiology, the penile strain gauge (PSG).

Aim

To (i) assess the validity of the LDI as a measure of male sexual arousal, (ii) evaluate the relationship between the LDI and PSG, and (iii) compare sexual concordance produced by the LDI and PSG.

Methods

A total of 25 male participants (Mage = 24.28 years, SD = 6.10, range 18–37) watched 4 experimental films (ie, anxiety-provoking, humorous, erotic, neutral nature content) while their sexual arousal was assessed. Genital sexual arousal was assessed using the LDI (blood perfusion) and PSG (penile tumescence) concurrently. Subjective sexual arousal was assessed using continuous and discrete self-reported measures.

Main Outcome Measure

Results demonstrate the validity of the LDI as an imaging-based measure of male genital arousal, and one that is comparable to the PSG.

Results

Significant increases in genital blood flow assessed via the LDI were observed for erotic, but not anxiety-provoking, humorous, or neutral films (F[1.65, 39.57] = 18.23, P < .001, ηp2 = .43). A moderate, positive correlation between genital arousal measured via the LDI and PSG concurrently was observed (r = .40), despite considerable across-participant variability. In the current sample, the LDI and PSG both produced strong sexual concordance estimates (r = .51 and r = .46, respectively). When all LDI and PSG concordance estimates were correlated, a moderate relationship was revealed (r = .37).

Clinical Implications

As a new imaging tool for male sexual psychophysiological arousal, the LDI holds promise for improving our understanding of issues related to men’s sexual health.

Strength & Limitations

Movement artifacts produced by penile engorgement were a limitation to the LDI as an imaging technique. Further, the LDI used in the current study was a discrete measure of arousal, whereas the PSG was continuous; future research would benefit by using continuous measurement capabilities of contemporary LDI systems.

Conclusion

As a valid measure of genital sexual arousal in men, the LDI holds promise as a tool that can be used to explore more nuanced questions about human sexuality, including cross-gender comparisons and real-time exploration of genital arousal patterns.
Novel Concept Enabling an Old Idea: A Flexible Electrode Array to Treat Neurogenic Erectile Dysfunction
Authors: Skoufias Spyridon , Sturny Mikaël , Fraga-Silva Rodrigo , Papaioannou Theodore G. , Stergiopoulos Nikolaos , Adamakis Ioannis , Constantinides Constantinos A.
Published: November 2018

Introduction

Many studies have shown that electrostimulation of the cavernosal nerve can induce and maintain penile erection. Based on these discoveries, neurostimulation to activate the erectile response has been considered a potential solution to treat erectile dysfunction (ED). However, despite recognized potential, this technology has not been further developed. The barrier is the complex anatomy of the human cavernous nerve, which challenges the intraoperative identification of the cavernosal nerves for electrode placement.

Aim

To overcome this major barrier, we proposed a practical solution: a 2-dimensional flexible electrode array that can cover the entire plexus area, ensuring that at least 1 of the electrodes will be in optimal contact with the cavernosal nerve, without the need of intraoperative identification. The present study aims to evaluate this concept intraoperatively.

Methods

24 patients enrolled for open radical prostatectomy were recruited. During the surgical procedures, the electrode array was positioned on the pelvic plexus (on the prostatic apex or pelvic wall) and electrical stimulation was applied to induce penile erection. Penile erectile response was assessed by (i) visual change of penile tumescence and (ii) by a penile plethysmograph system.

Main Outcome Measure

Ability and success rate of evoking penile response were measured by applying electrical stimulation using the developed electrode array.

Results

Electrical stimulation produced immediate penile response in all cases when tested before (on prostatic apex) or after prostate removal (on pelvic wall). Clear visual penile engorgement was observed in 75% of the cases, whereas 25% showed minimal to moderate penile tumescence. As expected, patients with lower International Index of Erectile Function-5 score presented a reduced response, whereas stimulation before prostate removal showed greater response than following removal. Interestingly, erectile response was potentiated by bilateral stimulation (circumference increase [mm]: 2.7 ± 1.02 vs. 8.2 ± 1.9, P = .01).

Clinical Implications

These data bring sufficient proof of concept of a conceivable novel medical implant for the treatment of ED caused by mechanical nerve injury, such as prostatectomy and spinal cord injury.

Strength & Limitations

This is the first approach that can ensure the optimal site stimulation of the erectogenic neuronal path within the lower pelvic area and overcome the major barrier of individual anatomic variability. However, because this study was performed intraoperatively in an acute scenario, further studies are needed to evaluate its chronic efficacy for clinical practice.

Conclusion

The flexible electrode array concept can ensure the electrostimulation of erectogenic neuronal path when positioned on the prostate apex or pelvic floor.
Low Reynolds number proprotor aerodynamic performance improvement using the continuous surface curvature design approach
Authors: Avital E. J. , Korakianitis T. , Motallebi F.
Published: November 2018

Low Reynolds number blade profiles of ReC=105–2×105 as based on the chord length and used for small unnamed air vehicles, and near space applications are investigated for single and counter-rotating (co-axial) proprotors, i.e. acting as rotors or propellers. Such profiles are prone for early stall, significantly reducing their maximum lift to drag ratio. Two profiles previously designed by our continuous surface curvature design approach named as CIRCLE are investigated in order to improve the performance of the proprotors. The profiles are redesigns of the common symmetric NACA0012 and asymmetric E387 profiles. Using general arguments based on composite efficiency and rotor’s lift to drag ratio, the performance envelope is noticeably increased when using the redesigned profiles for high angles of attack due to stall delay.

A new approach is derived to account for the distance between the rotors of a co-axial proprotor. It is coupled with a blade element method and is verified against experimental results. Single and co-axial CIRCLE-based proprotors are investigated against the corresponding non-CIRCLE-based proprotors at hover and axial translation. Noticeable improvements are observed in thrust increase and power reduction at high angles of attack of the blade’s profiles, particularly for the co-axial configuration. Plots of thrust, torque, power, composite efficiency and aerodynamic efficiency distributions are given and analysed.
Transparency effects on policy compliance: disclosing how defaults work can enhance their effectiveness
Authors: PAUNOV YAVOR , WÄNKE MICHAELA , VOGEL TOBIAS
Published: November 2018

From an ethical standpoint, transparency is an essential requirement in public policy-making. Ideally, policy-makers are transparent and actively disclose the presence, purpose and means of a decision aid. From a practical point of view, however, transparency has been discussed as reducing the effectiveness of decision aids. In the present paper, we elaborate on how transparency affects the effectiveness of defaults. In three experiments, we manipulated whether the endorser was transparent about the default or not and assessed participants’ decisions to opt out or comply. Throughout the experiments, we found that proactive transparency reduced opt-out rates as compared to a non-transparent default condition. Moreover, proactive disclosure of a default reduced opt-out rates as compared to informed control groups, where participants imagined they had retrieved the default-related information by themselves (Studies 1 and 2). The results further indicate that a lack of proactive disclosure may lead targets to perceive the endorser as less sincere and to feel deceived, which in turn hinders the effectiveness of the default. In general, our findings lend support to the proactive transparency paradigm in governance and show that a default-based policy can be transparent and effective at the same time.
Antibiotic prescribing upon discharge from the hospital to long-term care facilities: Implications for antimicrobial stewardship requirements in post-acute settings
Authors: Weber Bo R. , Noble Brie N. , Bearden David T. , Crnich Christopher J. , Ellingson Katherine D. , McGregor Jessina C. , Furuno Jon P.
Published: November 2018

Objective

To quantify the frequency and outcomes of receiving an antibiotic prescription upon discharge from the hospital to long-term care facilities (LTCFs).

Design

Retrospective cohort study.

Setting

A 576-bed, academic hospital in Portland, Oregon.

Patients

Adult inpatients (≥18 years of age) discharged to an LTCF between January 1, 2012, and June 30, 2016.

Methods

Our primary outcome was receiving a systemic antibiotic prescription upon discharge to an LTCF. We also quantified the association between receiving an antibiotic prescription and 30-day hospital readmission, 30-day emergency department (ED) visit, and Clostridium difficile infection (CDI) on a readmission or ED visit at the index facility within 60 days of discharge.

Results

Among 6,701 discharges to an LTCF, 22.9% were prescribed antibiotics upon discharge. The most prevalent antibiotic classes prescribed were cephalosporins (20.4%), fluoroquinolones (19.1%), and penicillins (16.7%). The medical records of ~82% of patients included a diagnosis code for a bacterial infection on the index admission. Among patients prescribed an antibiotic upon discharge, the incidence of 30-day hospital readmission to the index facility was 15.9%, the incidence of 30-day ED visit at the index facility was 11.0%, and the incidence of CDI on a readmission or ED visit within 60 days of discharge was 1.6%. Receiving an antibiotic prescription upon discharge was significantly associated with 30-day ED visits (adjusted odds ratio [aOR], 1.2; 95% confidence interval [CI], 1.02–1.5) and with CDI within 60 days (aOR, 1.7; 95% CI, 1.02–2.8) but not with 30-day readmissions (aOR, 1.01; 95% CI, 0.9–1.2).

Conclusions

Antibiotics were frequently prescribed upon discharge to LTCFs, which may be associated with increased risk of poor outcomes post discharge.
An autofocusing method for imaging the targets for TWI radar systems with correction of thickness and dielectric constant of wall
Authors: Kaushal Sandeep , Kumar Bambam , Singh Dharmendra
Published: November 2018

In through the wall imaging systems, wall parameters like its thickness and dielectric constant play an important role in the true and correct image formation of an object behind the wall made of various materials like brick cement, wood, plastic, etc. Incorrect estimation of these parameters leads to dislocation of the object and smearing or blurriness of the image too. A new autofocusing technique for a stepped frequency continuous wave -based radar at the frequency of 1–3 Ghz has been developed that corrects the wall's parameters like its thickness and dielectric constant and provides a better focused image of the target. For this purpose, a peak signal to noise ratio -based autofocusing technique has been developed by using curve fitting and the genetic algorithm. It is observed that the proposed technique has capability to focus the image up to good extent.
Distribution of PPX2 Mutations Conferring PPO-Inhibitor Resistance in Palmer Amaranth Populations of Tennessee
Authors: Copeland J. Drake , Giacomini Darci A. , Tranel Patrick J. , Montgomery Garret B. , Steckel Lawrence E.
Published: November 2018

Protoporphyrinogen IX oxidase (PPO)–inhibiting herbicides (WSSA Group 14) have been used in agronomic row crops for over 50 yr. Broadleaf weeds, including glyphosate-resistant Palmer amaranth, have been controlled by this herbicide site of action PRE and POST. Recently, Palmer amaranth populations were reported resistant to PPO inhibitors in 2011 in Arkansas, in 2015 in Tennessee, and in 2016 in Illinois. Historically, the mechanism for this resistance involves the deletion of a glycine at position 210 (ΔG210) in a PPO enzyme encoded by the PPX2 gene; however, the ΔG210 deletion did not explain all PPO inhibitor–resistant Palmer amaranth in Tennessee populations. Recently, two new mutations within PPX2 (R128G, R128M) that confer resistance to PPO inhibitors were identified in Palmer amaranth. Therefore, research is needed to document the presence and distribution of the three known mutations that confer PPO inhibitor resistance in Tennessee. In 2017, a survey was conducted in 18 fields with Palmer amaranth to determine whether resistance existed and the prevalence of each known mutation in each field. Fomesafen was applied at 265 g ai ha–1 to Palmer amaranth infestations within each field to select for resistant weeds for later analysis. Where resistance was described (70% of surviving plants), the ΔG210 mutation was detected in 47% of resistant plants. The R128G mutation accounted for 42% of resistance, similar to the frequency of the ΔG210 mutation. The R128M mutation was less frequent than the other two mutations, accounting for only 10% of the resistance. All mutations detected in this study were heterozygous. Additionally, no more than one of the three PPX2 mutations were detected in an individual surviving plant. Similar to previous research, about 70% of PPO resistance was accounted for by these three known mutations, leaving about 30% of resistance not characterized in Tennessee populations. Survivors not showing the three known PPO mutations suggest that other resistance mechanisms are present.
Satellite Observations of Ocean Surface Winds and Currents
Authors: Bourassa Mark , Rodriguez Ernesto , Gille Sarah
Published: November 2018

Florida State University workshop on Satellite Observations of Ocean Surface Winds & Currents; La Jolla, California, 18–19 May 2018
Marshall Receives 2018 Luna B. Leopold Young Scientist Award
Authors:   AGU
Published: November 2018

Jill Marshall will receive the 2018 Luna B. Leopold Young Scientist Award at AGU’s Fall Meeting 2018, to be held 10–14 December in Washington, D. C. The award recognizes a young scientist for “a significant and outstanding contribution that advances the field of Earth and planetary surface processes.”
Gross Receives 2018 Ivan I. Mueller Award for Distinguished Service and Leadership
Authors:   AGU
Published: November 2018

Richard Gross will receive the 2018 Ivan I. Mueller Award for Distinguished Service and Leadership at AGU’s Fall Meeting 2018, to be held 10–14 December in Washington, D. C. The award acknowledges “major achievements in service to and/or leadership within the field of geodesy.”
De Groot Receives 2018 William Gilbert Award
Authors:   AGU
Published: November 2018

Lennart de Groot will receive the 2018 William Gilbert Award at AGU’s Fall Meeting 2018, to be held 10–14 December in Washington, D. C. The award recognizes “outstanding and unselfish work in magnetism of Earth materials and of the Earth and planets.”
Volcano in Iceland Is One of the Largest Sources of Volcanic CO2
Authors: Cook Terri
Published: November 2018

High-precision airborne measurements, in combination with atmospheric modeling, suggest that the Katla subglacial caldera may be one of the planet’s biggest sources of volcanic carbon dioxide.
Election Results Offer Hope for Climate Action
Authors: Showstack Randy
Published: November 2018

The Democrats’ control of the House of Representatives promises to provide checks and balances on the Trump administration, environmental leaders say.
Ground Deformations in the Corinth Rift, Greece, Investigated Through the Means of SAR Multitemporal Interferometry
Authors: Elias P. , Briole P.
Published: November 2018

The Corinth Rift is one of the narrowest and fastest extending continental regions worldwide and has one of the highest seismicity rates in the Euro‐Mediterranean region. At its western termination, several active faults are located beneath the city of Patras and the surrounding area, a region of major socioeconomic importance for Greece. Displacement rates for the period 2002–2010 obtained from ascending and descending ASAR/ENVISAT multitemporal interferometry are combined with Global Positioning System measurements from permanent and campaign stations to produce a map of vertical and east‐west ground velocities. Cross sections are produced in order to quantify the deformation rates with higher precision. In the vertical, the motion combines tectonic deformation, urban subsidence, and subsidence due to deltaic sediments compaction. In the city of Patras and through the gulf of Patras, the northern continuation of the 2008 Movri earthquake fault is connected to the oblique transform zone of Rio. Further east, our observations suggest the existence of postseismic deformation at Aigion in the 15 years following the Mw = 6.2, 15 June 1995 Aigion earthquake. The inferred deforming zone, assuming a simple slow slipping model, is located at the western end of the 1995 fault, with radius ~3.5 km, centroid depth ~4 km, and cumulated postseismic moment representing 28% of the coseismic. Alluvial fan deltas subside due to their compaction with a gradient that increases toward the shore. Several of those deltas are located in the hanging‐wall of active faults.
The Cathles Parameter (Ct): A Geodynamic Definition of the Asthenosphere and Implications for the Nature of Plate Tectonics
Authors: Richards Mark A. , Lenardic Adrian
Published: November 2018

A weak asthenosphere, or low‐viscosity zone (LVZ), underlying Earth's lithosphere has played an important role in interpreting isostasy, postglacial rebound (PGR), and the seismic LVZ, as well as proposed mechanisms for continental drift, plate tectonics, and postseismic relaxation. Consideration of the resolving power of PGR, postseismic relaxation, and geoid modeling studies suggests a sublithospheric LVZ perhaps ~100–200 km thick with a viscosity contrast of ~100–1,000. Ab initio numerical models of plate‐like boundary layer motions in mantle convection also suggest a key role for the LVZ. Paradoxically, a thinner LVZ with a strong viscosity contrast is most effective in promoting plate‐like surface motions. These numerical results are explained in terms of the reduction in horizontal shear dissipation due to an LVZ, and a simple scaling theory leads to somewhat nonintuitive model predictions. For example, an LVZ causes stress magnification at the base of the lithosphere, enhancing plate boundary formation. Also, flow within the LVZ may be driven by the plates (Couette flow), or pressure‐driven from within the mantle (Poiseuille flow), depending upon the degree to which plates locally inhibit or drive underlying mantle convection. For studies of the long‐wavelength geoid, PGR, and mantle convection, a simple dimensionless parameter controls the effect of the LVZ. This “Cathles parameter” is given by Ct = η*(D/λ)3, where η* is the viscosity contrast, D is the thickness of the LVZ, and λ is the flow wavelength, emphasizing the tightly coupled trade‐off between LVZ thickness and viscosity contrast.
Challenges in the Search for Perchlorate and Other Hydrated Minerals With 2.1‐μm Absorptions on Mars
Authors: Leask E. K. , Ehlmann B. L. , Dundar M. M. , Murchie S. L. , Seelos F. P.
Published: November 2018

A previously unidentified artifact has been found in Compact Reconnaissance Imaging Spectrometer for Mars targeted I/F data. It exists in a small fraction (<0.05%) of pixels within 90% of images investigated and occurs in regions of high spectral/spatial variance. This artifact mimics real mineral absorptions in width and depth and occurs most often at 1.9 and 2.1 μm, thus interfering in the search for some mineral phases, including alunite, kieserite, serpentine, and perchlorate. A filtering step in the data processing pipeline, between radiance and I/F versions of the data, convolves narrow artifacts (“spikes”) with real atmospheric absorptions in these wavelength regions to create spurious absorption‐like features. The majority of previous orbital detections of alunite, kieserite, and serpentine we investigated can be confirmed using radiance and raw data, but few to none of the perchlorate detections reported in published literature remain robust over the 1.0‐ to 2.65‐μm wavelength range.
Understanding End‐of‐Century Snowpack Changes Over California's Sierra Nevada
Authors: Sun Fengpeng , Berg Neil , Hall Alex , Schwartz Marla , Walton Daniel
Published: November 2018

This study uses dynamical and statistical methods to understand end‐of‐century mean changes to Sierra Nevada snowpack. Dynamical results reveal that middle‐elevation watersheds experience considerably more rain than snow during winter, leading to substantial snowpack declines by spring. Despite some high‐elevation watersheds receiving slightly more snow in January and February, the warming signal still dominates across the wet season and leads to notable declines by springtime. A statistical model is created to mimic dynamical results for 1 April snowpack, allowing for an efficient downscaling of all available general circulation models from the Coupled Model Intercomparison Project phase 5. For all general circulation models and emission scenarios, dramatic 1 April snowpack loss occurs at elevations below 2,500 m, despite increased precipitation in many general circulation models. Only 36% (±12%) of historical 1 April total snow water equivalent volume remains at the century's end under a “business‐as‐usual” emission scenario, with 70% (±12%) remaining under a realistic “mitigation” scenario.
Subduction by Submesoscales
Authors: Canuto V. M. , Cheng Y. , Howard A. M.
Published: November 2018

Several studies have demonstrated the relevance of submesoscales (SM) to the production of phytoplankton and the ocean absorption of anthropogenic CO2. One variable that thus far has not been fully quantified is the SM‐induced rates of subduction and obduction at the bottom of the mixed layer. In this work, we use an SM parameterization that had been previously assessed to estimate the rates of subduction‐obduction using a coarse resolution stand‐alone ocean code to compute the large‐scale fields. To separate the contributions of baroclinic instabilities from those due to wind stress, we derive an analytic expression for the SM subduction‐obduction rates. Since there are no numerical simulations and/or measurements to assess the results, we compare them to subduction rates due to mesoscales for which an eddy‐permitting southern ocean state estimate is available. An interesting result is that in the Antarctic Circumpolar Current the maximum SM subduction rates are not significantly smaller than those due to mesoscales, but the SM subduction rates exhibit a topology opposite to that of mesoscales: obduction is equatorward and subduction is poleward. Sensitivity studies are presented to explore the dependence of the results on the depth of the SM vertical extent and the SM kinetic energy. On the basis of these results, it is suggested that the SM‐induced subduction should not be neglected because topology and magnitude indicate that mesoscales and submesoscales may add to or subtract from one another.
Snow Hydrology in the Upper Yellow River Basin Under Climate Change: A Land Surface Modeling Perspective
Authors: Liu Wenbin , Wang Lei , Sun Fubao , Li Zehua , Wang Hong , Liu Jiahong , Yang Tao , Zhou Jing , Qi Jia
Published: November 2018

Snow has been widely recognized as a crucial component of water resources and is expected to be vulnerable to climate change in cold and mountainous regions. Here we projected climate change impacts on snow hydrology in the upper Yellow River (UYR) basin through a distributed biosphere hydrological model with improved snow physics, forced with Inter‐Sectoral Impact Model Intercomparison Project climate model outputs under two emission scenarios (representative concentration pathways, RCP4.5 and RCP8.5) during the period of 1996–2025. The results indicated that the climate in the UYR basin is turning warmer and wetter. In this context, more precipitation would occur as rain (snow‐to‐precipitation ratio would decrease accordingly). The total runoff generation would increase slightly with increased precipitation. The simulated snow depth and snow water equivalent would decrease by 33% and 19% per 1 °C warming under the RCP4.5. These declined rates would further enlarge under the RCP8.5. Accordingly, the multimodel ensemble mean snowmelt‐to‐runoff ratio decreases by 9% and 7% per 1 °C warming under the two emission scenarios. The projected responses of snow hydrology (e.g., snow depth, snow water equivalent, and snowmelt) to the changing climate in the UYR basin are consistent among different climate models and RCP scenarios, which would provide valuable insights for water resources management, environmental protection, and climate change adaption in high mountainous basins and their downstream regions.
The Impact of Hybrid Usage of a Cumulus Parameterization Scheme on Tropical Convection and Large‐Scale Circulations in a Global Cloud‐System Resolving Model
Authors: Miyakawa Tomoki , Noda Akira T. , Kodama Chihiro
Published: November 2018

The impact of activating a cumulus parameterization scheme in the global nonhydrostatic icosahedral atmospheric model (NICAM) coupled with a one‐dimensional (1‐D) mixed‐layer ocean model is assessed using a cloud‐system‐resolving, 14‐km mesh. The Chikira‐Sugiyama (CS) scheme, which employs an entrainment rate sensitive to the humidity of the environment, can consider congestus clouds in the tropics when used in conventional global climate models. Congestus clouds are underresolved in the default 14‐km mesh NICAM. In the present study, boreal summer NICAM simulations are performed with and without the CS scheme, and several different scheme parameters are evaluated. The results show that the horizontal scale of convection and precipitable water increased in the tropics when using the CS scheme. Model adjustments were apparent at two different timescales: a rapid adjustment within the first week and a slower adjustment at 1 to 2 months. Both effects were magnified in the simulations that employed smaller values for the parameter that defines the fractional of loss of buoyancy‐generated energy in parameterized convection. The upward branch of the Hadley circulation shifted northward, and the Walker circulation was enhanced when the CS scheme was activated. These large‐scale adjustments suggested that increased midtropospheric moisture in the tropics tends to favor larger organized convective activities, which require an abundant supply of moisture, which, in this case, is available to the north of the equatorial West Pacific Ocean.
The spread of low-credibility content by social bots
Authors: Shao Chengcheng , Ciampaglia Giovanni Luca , Varol Onur , Yang Kai-Cheng , Flammini Alessandro , Menczer Filippo
Published: November 2018

The massive spread of digital misinformation has been identified as a major threat to democracies. Communication, cognitive, social, and computer scientists are studying the complex causes for the viral diffusion of misinformation, while online platforms are beginning to deploy countermeasures. Little systematic, data-based evidence has been published to guide these efforts. Here we analyze 14 million messages spreading 400 thousand articles on Twitter during ten months in 2016 and 2017. We find evidence that social bots played a disproportionate role in spreading articles from low-credibility sources. Bots amplify such content in the early spreading moments, before an article goes viral. They also target users with many followers through replies and mentions. Humans are vulnerable to this manipulation, resharing content posted by bots. Successful low-credibility sources are heavily supported by social bots. These results suggest that curbing social bots may be an effective strategy for mitigating the spread of online misinformation.
Conditional deletion of Rcan1 predisposes to hypertension-mediated intramural hematoma and subsequent aneurysm and aortic rupture
Authors: Villahoz Silvia , Yunes-Leites Paula Sofía , Méndez-Barbero Nerea , Urso Katia , Bonzon-Kulichenko Elena , Ortega Sagrario , Nistal J. Francisco , Vazquez Jesus , Offermanns Stefan , Redondo Juan Miguel , Campanero Miguel R.
Published: November 2018

Aortic intramural hematoma (IMH) can evolve toward reabsorption, dissection or aneurysm. Hypertension is the most common predisposing factor in IMH and aneurysm patients, and the hypertensive mediator angiotensin-II induces both in mice. We have previously shown that constitutive deletion of Rcan1 isoforms prevents Angiotensin II-induced aneurysm in mice. Here we generate mice conditionally lacking each isoform or all isoforms in vascular smooth muscle cells, endothelial cells, or ubiquitously, to determine the contribution to aneurysm development of Rcan1 isoforms in vascular cells. Surprisingly, conditional Rcan1 deletion in either vascular cell-type induces a hypercontractile phenotype and aortic medial layer disorganization, predisposing to hypertension-mediated aortic rupture, IMH, and aneurysm. These processes are blocked by ROCK inhibition. We find that Rcan1 associates with GSK-3β, whose inhibition decreases myosin activation. Our results identify potential therapeutic targets for intervention in IMH and aneurysm and call for caution when interpreting phenotypes of constitutively and inducibly deficient mice.
A diagnosis of the plasma waves responsible for the explosive energy release of substorm onset
Authors: Kalmoni N. M. E. , Rae I. J. , Watt C. E. J. , Murphy K. R. , Samara M. , Michell R. G. , Grubbs G. , Forsyth C.
Published: November 2018

During geomagnetic substorms, stored magnetic and plasma thermal energies are explosively converted into plasma kinetic energy. This rapid reconfiguration of Earth’s nightside magnetosphere is manifest in the ionosphere as an auroral display that fills the sky. Progress in understanding of how substorms are initiated is hindered by a lack of quantitative analysis of the single consistent feature of onset; the rapid brightening and structuring of the most equatorward arc in the ionosphere. Here, we exploit state-of-the-art auroral measurements to construct an observational dispersion relation of waves during substorm onset. Further, we use kinetic theory of high-beta plasma to demonstrate that the shear Alfven wave dispersion relation bears remarkable similarity to the auroral dispersion relation. In contrast to prevailing theories of substorm initiation, we demonstrate that auroral beads seen during the majority of substorm onsets are likely the signature of kinetic Alfven waves driven unstable in the high-beta magnetotail.
Martian magmatism from plume metasomatized mantle
Authors: Day James M. D. , Tait Kimberly T. , Udry Arya , Moynier Frédéric , Liu Yang , Neal Clive R.
Published: November 2018

Direct analysis of the composition of Mars is possible through delivery of meteorites to Earth. Martian meteorites include ∼165 to 2400 Ma shergottites, originating from depleted to enriched mantle sources, and ∼1340 Ma nakhlites and chassignites, formed by low degree partial melting of a depleted mantle source. To date, no unified model has been proposed to explain the petrogenesis of these distinct rock types, despite their importance for understanding the formation and evolution of Mars. Here we report a coherent geochemical dataset for shergottites, nakhlites and chassignites revealing fundamental differences in sources. Shergottites have lower Nb/Y at a given Zr/Y than nakhlites or chassignites, a relationship nearly identical to terrestrial Hawaiian main shield and rejuvenated volcanism. Nakhlite and chassignite compositions are consistent with melting of hydrated and metasomatized depleted mantle lithosphere, whereas shergottite melts originate from deep mantle sources. Generation of martian magmas can be explained by temporally distinct melting episodes within and below dynamically supported and variably metasomatized lithosphere, by long-lived, static mantle plumes.
Samarium(II) folding cascades involving hydrogen atom transfer for the synthesis of complex polycycles
Authors: Plesniak Mateusz P. , Garduño-Castro Monserrat H. , Lenz Philipp , Just-Baringo Xavier , Procter David J.
Published: November 2018

The expedient assembly of complex, natural product-like small molecules can deliver new chemical entities with the potential to interact with biological systems and inspire the development of new drugs and probes for biology. Diversity-oriented synthesis is a particularly attractive strategy for the delivery of complex molecules in which the 3-dimensional architecture varies across the collection. Here we describe a folding cascade approach to complex polycyclic systems bearing multiple stereocentres mediated by reductive single electron transfer (SET) from SmI2. Simple, linear substrates undergo three different folding pathways triggered by reductive SET. Two of the radical cascade pathways involve the activation and functionalization of otherwise inert secondary alkyl and benzylic groups by 1,5-hydrogen atom transfer (HAT). Combination of SmI2, a privileged reagent for cascade reactions, and 1,5-HAT can lead to complexity-generating radical sequences that unlock access to diverse structures not readily accessible by other means.
A tumor-targeted trimeric 4-1BB-agonistic antibody induces potent anti-tumor immunity without systemic toxicity
Authors: Compte Marta , Harwood Seandean Lykke , Muñoz Ines G. , Navarro Rocio , Zonca Manuela , Perez-Chacon Gema , Erce-Llamazares Ainhoa , Merino Nekane , Tapia-Galisteo Antonio , Cuesta Angel M. , Mikkelsen Kasper , Caleiras Eduardo , Nuñez-Prado Natalia , Aznar M. Angela , Lykkemark Simon , Martínez-Torrecuadrada Jorge , Melero Ignacio , Blanco Francisco J. , Bernardino de la Serna Jorge , Zapata Juan M. , Sanz Laura , Alvarez-Vallina Luis
Published: November 2018

The costimulation of immune cells using first-generation anti-4-1BB monoclonal antibodies (mAbs) has demonstrated anti-tumor activity in human trials. Further clinical development, however, is restricted by significant off-tumor toxicities associated with FcγR interactions. Here, we have designed an Fc-free tumor-targeted 4-1BB-agonistic trimerbody, 1D8N/CEGa1, consisting of three anti-4-1BB single-chain variable fragments and three anti-EGFR single-domain antibodies positioned in an extended hexagonal conformation around the collagen XVIII homotrimerization domain. The1D8N/CEGa1 trimerbody demonstrated high-avidity binding to 4-1BB and EGFR and a potent in vitro costimulatory capacity in the presence of EGFR. The trimerbody rapidly accumulates in EGFR-positive tumors and exhibits anti-tumor activity similar to IgG-based 4-1BB-agonistic mAbs. Importantly, treatment with 1D8N/CEGa1 does not induce systemic inflammatory cytokine production or hepatotoxicity associated with IgG-based 4-1BB agonists. These results implicate FcγR interactions in the 4-1BB-agonist-associated immune abnormalities, and promote the use of the non-canonical antibody presented in this work for safe and effective costimulatory strategies in cancer immunotherapy.
Lattice-contraction triggered synchronous electrochromic actuator
Authors: Li Kerui , Shao Yuanlong , Yan Hongping , Lu Zhi , Griffith Kent J. , Yan Jinhui , Wang Gang , Fan Hongwei , Lu Jingyu , Huang Wei , Bao Bin , Liu Xuelong , Hou Chengyi , Zhang Qinghong , Li Yaogang , Yu Junsheng , Wang Hongzhi
Published: November 2018

Materials with synchronous capabilities of color change and actuation have prospects for application in biomimetic dual-stealth camouflage and artificial intelligence. However, color/shape dual-responsive devices involve stimuli that are difficult to control such as gas, light or magnetism, and the devices show poor coordination. Here, a flexible composite film with electrochromic/actuating (238° bending angle) dual-responsive phenomena, excellent reversibility, high synchronization, and fast response speed (< 5 s) utilizes a single active component, W18O49 nanowires. From in situ synchrotron X-ray diffraction, first principles calculations/numerical simulations, and a series of control experiments, the actuating mechanism for macroscopic deformation is elucidated as pseudocapacitance-based reversible lattice contraction/recovery of W18O49 nanowires (i.e. nanostructure change at the atomic level) during lithium ion intercalation/de-intercalation. In addition, we demonstrate the W18O49 nanowires in a solid-state ionic polymer-metal composite actuator that operates stably in air with a significant pseudocapacitive actuation.