bluuebunny/crossref_metadata_2025 huggingface dataset:
A simplified framework to optimize MRI contrast preparation
Authors: Reeth Eric Van , Ratiney Hélène , Tse Ve Koon Kevin , Tesch Michael , Grenier Denis , Beuf Olivier , Glaser Steffen J. , Sugny Dominique
Published: September 2018

Purpose

This article proposes a rigorous optimal control framework for the design of preparation schemes that optimize MRI contrast based on relaxation time differences.

Methods

Compared to previous optimal contrast preparation schemes, a drastic reduction of the optimization parameter number is performed. The preparation scheme is defined as a combination of several block pulses whose flip angles, phase terms and inter‐pulse delays are optimized to control the magnetization evolution.

Results

The proposed approach reduces the computation time of ‐robust preparation schemes to around a minute (whereas several hours were required with previous schemes), with negligible performance loss. The chosen parameterization allows to formulate the total preparation duration as a constraint, which improves the overall compromise between contrast performance and preparation time. Simulation, in vitro and in vivo results validate this improvement, illustrate the straightforward applicability of the proposed approach, and point out its flexibility in terms of achievable contrasts. Major improvement is especially achieved for short‐T2 enhancement, as shown by the acquisition of a non‐trivial contrast on a rat brain, where a short‐T2 white matter structure (corpus callosum) is enhanced compared to surrounding gray matter tissues (hippocampus and neocortex).

Conclusions

This approach proposes key advances for the design of optimal contrast preparation sequences, that emphasize their ability to generate non‐standard contrasts, their potential benefit in a clinical context, and their straightforward applicability on any MR system.
Size and Age of Stonecats in Lake Champlain; Estimating Growth at the Margin of their Range to Aid in Population Management
Authors: Puchala Elizabeth A. , Parrish Donna L. , Ogle Derek H.
Published: September 2018

Little is known about populations of Stonecat Noturus flavus, especially in the northeastern United States, where they are at the edge of their range. In Lake Champlain tributaries, Stonecats are listed as endangered in Vermont but not in New York. Here we describe the growth of Stonecats in two tributaries to Lake Champlain, one in Vermont (LaPlatte River), which was our primary interest, and one in New York (Great Chazy River), with von Bertalanffy growth models fit to lengths at the times of marking and recapture and to observed length and age data. We also compared growth of Stonecats in these waters to results from other locations near the middle of their distribution. Stonecats in the Great Chazy River were larger at ages 1–3, but similar in size for ages 4 and 5, than Stonecats from the LaPlatte River. Stonecats in Lake Champlain tributaries were generally larger at age than those from the middle of their range, except for those from Lake Erie. From our mean length-at-age results and previous literature estimates of length at maturity for Stonecats, it appears that Stonecats in Lake Champlain reach maturity by age 3, though future research that directly estimates age at maturity would be more informative. These results will help managers assess the effect of various environmental and human stressors that Stonecats have experienced in the Lake Champlain basin in recent years. Furthermore, our results expand the literature, which lacks information about growth of this species. Finally, our mark–recapture approach to estimating growth of Stonecats can be applied to other species, especially where data are limited because of their status, and in other systems.
Proteomic Profiling of Iron‐Treated Ovarian Cells Identifies AKT Activation that Modulates the CLEAR Network
Authors: Rockfield Stephanie , Guergues Jennifer , Rehman Nabila , Smith Aaron , Bauckman Kyle A. , Stevens Stanley M. , Nanjundan Meera
Published: September 2018

Although iron is essential for cell survival, dysregulated levels can contribute to cancer development or even cell death. The underlying mechanisms mediating these events remain unclear. Herein, proteomic alterations are assessed in iron‐treated ovarian cell lines using reverse phase protein array (RPPA) technology and potential functional responses via ingenuity pathway analysis (IPA). Using these approaches, upregulation of pathways modulating organismal death with alterations in mTOR, MAPK, and AKT signaling in HEY ovarian cancer cells in contrast to T80 non‐malignant ovarian cells is noted. Since modulation of cell death is mediated in part via microphthalmia‐associated transcription factor (MiTF) family, which regulates lysosomal biogenesis and autophagosome formation by upregulating expression of coordinated lysosomal expression and regulation (CLEAR) network, expression changes in these factors in response to iron are investigated. Increased transcription factor EB (TFEB) in T80 (relative to HEY), accompanied by its nuclear translocation and increased CLEAR network gene expression with iron, is identified. Inhibition of AKT alters these responses in contrast to mTOR inhibition, which has little effect. Collectively, these findings support use of RPPA/IPA technology to predict functional responses to iron and further implicate AKT pathway and MiTF members in iron‐induced cellular responses in ovarian cells.
Sustainable poly(ether amide)s from lignin‐derived precursors
Authors: Saenz Guery , Scott Colleen
Published: September 2018

In recent years, there have been concerted efforts to replace petrochemical products with those from renewable sources due to the unsustainability of petroleum feedstock, and the continued volatility in the price. This work describes the synthesis and thermal properties of two new lignin‐derived poly(ether‐amide)s as alternative thermoplastics to petroleum‐based commodities. Poly‐4‐(2‐aminoethoxy)benzoate (PEAB) and poly‐4‐(2‐aminoethoxy)‐3‐methoxybenzoate (PEAV) are synthesized by a melt polycondensation and characterized by 1H NMR spectroscopy and thermal analysis. The number average molecular weight (Mn) of the polymers are estimated from the 1H NMR spectroscopy analysis, and were shown to be 4100 and 12,000 g/mol for PEAB and PEAV respectively. The PEAB had a higher decomposition temperature (Td) as well as glass transition temperature (Tg) compared to PEAV; albeit, with a lower molecular weight. The polymers’ Td were in the range of 330 °C–380 °C and the Tg were between 100 °C and 120 °C. The thermal properties of the polymers are in the desirable range for thermoplastic materials used in the packaging, storage, and coating industries. Furthermore, the polymers are susceptible to degradation under acidic conditions in a short period; a property that is highly desirable for degradable polymers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2154–2160
dS Supergravity from 10d
Authors: Kallosh Renata , Wrase Timm
Published: September 2018

We consider flux compactification of type II string theory with local sources on SU(3)‐structure manifolds. By adding pseudo‐calibrated anti‐‐branes wrapped on supersymmetric cycles we generalize all existing models so that the effective , supergravity now includes a nilpotent multiplet. We present a new dictionary between string theory models and Kähler potential K and superpotential W for these dS supergravities with a nilpotent multiplet and non‐linearly realized local supersymmetry. In addition to KKLT and LVS with uplifting ‐branes, we have now new models with uplifting , , , ‐branes. The new uplifting contribution to the supergravity potential due to Volkov‐Akulov supersymmetry is universal. As one application of our general result, we study classical flux compactifications of type IIA supergravity and find that a previously discovered universal tachyon is now absent.
Population Pharmacokinetics and Exploratory Exposure‐Response Relationships of Diazepam in Children Treated for Status Epilepticus
Authors: Ku Lawrence C. , Hornik Christoph P. , Beechinor Ryan J. , Chamberlain James M. , Guptill Jeffrey T. , Harper Barrie , Capparelli Edmund V. , Martz Karen , Anand Ravinder , Cohen‐Wolkowiez Michael , Gonzalez Daniel ,   on behalf of the Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee
Published: September 2018

Diazepam is labeled for status epilepticus (SE) in children, but there are limited data characterizing its disposition in pediatric patients. We developed a population pharmacokinetic (PK) model of i.v. diazepam in children with SE. We evaluated relationships between PK parameters and both safety and efficacy, and simulated exposures using dosing regimens from the product label and clinical practice. The model was developed using prospective data from a pediatric clinical trial comparing diazepam to lorazepam for treatment of SE. Altogether, 87 patients aged ≥ 3 months to < 18 years contributed 162 diazepam concentrations. Diazepam PKs were well characterized by a two‐compartment model scaled by body size. No significant or clinically important relationships were observed between diazepam PKs and safety or efficacy. Simulations demonstrated that, compared with label dosing, the study dose (0.2 mg/kg i.v., maximum 8 mg) resulted in greater frequency in rapidly achieving the target therapeutic range of 200–600 ng/mL.
Electronic structure calculation of vanadium‐and scandium‐based endohedral fullerenes VSc2N@C2n (2n = 70, 76, 78, 80)
Authors: Bhusal Shusil , Baruah Tunna , Yamamoto Yoh , Zope Rajendra R.
Published: September 2018

We present candidate structures for the most stable isomers for the VSc2N@C70, VSc2N@C76, VSc2N@C78, and VSc2N@C80 using a systematic procedure that involves all possible isomers of the host fullerene cages. Subsequently, a detailed investigation of structural and electronic properties of the lowest energy isomers is performed using density functional theory in combination with large polarized Gaussian basis sets. The search correctly identifies the experimentally observed VSc2N@C80 isomer as the most stable structure. The structural analysis shows that only VSc2N@C70 has a non‐IPR cage among the four endohedral fullerenes. Respectively, VSc2N@C70 and VSc2N@C76 have nearly degenerate spin states with total spin S = 0 and S = 1. All the lowest energy cages are energetically stable and show significant electron accepting capacity comparable to C60.
Localized orbitals for optimal decomposition of molecular properties
Authors: Nikolaienko Tymofii Y. , Bulavin Leonid A.
Published: September 2018

We present the procedure for transforming delocalized molecular orbitals into the localized property‐optimized orbitals (LPOs) designed for building the most accurate, in the Frobenius norm sense, approximation to the first‐order reduced density matrix in form of the sum of localized monoatomic and diatomic terms. In this way, a decomposition of molecular properties into contributions associated with individual atoms and the pairs of atoms is obtained with the a priori known upper bound for the decomposition accuracy. Additional algorithm is proposed for obtaining the set of “the Chemist's LPOs” (CLPOs) containing a single localized orbital, with nearly double occupancy, per a pair of electrons. CLPOs form an idealized Lewis structure optimized for the closest possible reproduction of one‐electron properties derived from the original many‐electron wavefunction. The computational algorithms for constructing LPOs and CLPOs from a general wavefunction are presented and their implementation within the open‐source freeware program JANPA (http://janpa.sourceforge.net/) is discussed. The performance of the proposed procedures is assessed using the test set of density matrices of 33 432 small molecules obtained at both Hartree‐Fock and second‐order Moller‐Plesset theory levels and excellent agreement with the chemist's Lewis‐structure picture is found.
Open versus robotic partial nephrectomy: Systematic review and meta‐analysis of contemporary studies
Authors: Tsai Sheng‐Han , Tseng Ping‐Tao , Sherer Benjamin A. , Lai Yi‐Chen , Lin Pao‐Yen , Wu Ching‐Kuan , Stoller Marshall L.
Published: September 2018

Objectives

To compare perioperative outcomes of robotic‐assisted partial nephrectomy (RaPN) with open partial nephrectomy (OPN).

Methods

Systematically search through PubMed, Embase, ClinicalKey, Cochrane Library, ProQuest, ScienceDirect, Web of Science, and ClinicalTrials.gov for eligible studies was performed to April 11, 2018. A meta‐analysis was conducted for studies comparing RaPN and OPN. Confounding variables were assessed by meta‐regression or subgroup analysis.

Results

This study included 34 studies with 60 808 patients. Meta‐analysis revealed less blood loss, less transfusion, longer operative time, less postoperative complications, lower readmission rate, shorter length of stay, and less estimated glomerular filtration rate (eGFR) decline in RaPN groups. The superiority of RaPN in blood loss was attenuated with highly complex renal masses. The superiority of RaPN in intraoperative complications was strengthened with renal hilar control. The advantage of RaPN in surgical margin was increased in patient with body mass index (BMI) < 28.

Conclusions

Compared with OPN, RaPN provided lower morbidities and better renal function preservation.
Behavior of copper and zinc metals in soil profile, submitted to different sources of fertilization
Authors: da Rosa Genesio Mario , Gabriel Márcia , Wastowski Arci Dirceu , da Rosa Rodrigo Silveira
Published: September 2018

The application of high and continuous amounts of fertilizers to the soil can cause the accumulation of pollutants and biological agents, creating environmental and health problems. The objective of this work is to evaluate the presence and mobility within a soil profile of copper and zinc residual metals from chemical and organic fertilization after successive applications in three crops. The analysis was performed using X‐ray fluorescence spectrometry. The experiment is conducted with a drainage lysimeter set. The soil used is a dystroferric Red Latosol, fertilized with chemical (nitrogen–phosphorus–potassium [NPK]) and organic (poultry litter and swine manure) fertilizers. Soil samples were collected from three points in each lysimeter at depths of 0–10, 10–20, 20–30, and 30–40 centimeters, dried in an oven, ground, and analyzed by dispersive energy X‐ray fluorescence spectrometer. The copper and zinc elements from the successive applications of chemical and organic fertilization treatment accumulated in the soil profile. The use of the dispersive energy X‐ray fluorescence spectrometer allowed the evaluation of the presence and mobility of the copper and zinc elements in the soil profile; however, the observed values do not indicate their availability.
Sub synoptic scale features of the South Australia Storm of September 2016 – Part II: analysis of mechanisms driving the gusts
Authors: Earl Nick , Simmonds Ian
Published: September 2018

An extreme extratropical cyclone (ETC) struck South Australia on 28 September 2016, causing state‐wide blackouts and damage. In the second part of this two‐part study, we examine the extreme surface wind producing mechanisms within the ETC. ETCs have been extensively studied in the Northern Hemisphere (particularly in western Europe), highlighting the gust‐producing mesoscale features within. Before now, no Southern Hemisphere ETC has been examined in this way. There were a number of extreme gust‐producing features within the ETC, comparable to those observed in storms over western Europe. One such feature was a convective line, which caused many of the most extreme gusts and knocked out the state power grid. However, dry slot convection also contributed to the extremes, and this feature rarely causes extreme gusts in ETCs over the UK. Thus, further analysis is warranted to examine whether this is a common extreme‐gust‐producing ETC feature over Southern Australia. The strongest winds recorded throughout the event occurred on 29 September, and these were associated with the cold conveyor belt which spiralled around the low‐pressure centre.
R(D(∗)) from W ′ and right-handed neutrinos
Authors: Greljo Admir , Robinson Dean J. , Shakya Bibhushan , Zupan Jure
Published: September 2018

Abstract

We provide an ultraviolet (UV) complete model for the R(D
(∗)) anomalies, in which the additional contribution to semi-tauonic b → c transitions arises from decay to a right-handed sterile neutrino via exchange of a TeV-scale SU(2)
L
singlet W
′. The model is based on an extension of the Standard Model (SM) hypercharge group, U(1)
Y
, to the SU(2)
V
× U(1)′ gauge group, containing several pairs of heavy vector-like fermions. We present a comprehensive phenomenological survey of the model, ranging from the low-energy flavor physics, direct searches at the LHC, to neutrino physics and cosmology. We show that, while the W
′ and Z
′-induced constraints are important, it is possible to find parameter space naturally consistent with all the available data. The sterile neutrino sector also offers rich phenomenology, including possibilities for measurable dark radiation, gamma ray signals, and displaced decays at colliders.
Varieties of responsibility: two problems of responsible innovation
Authors: van de Poel Ibo , Sand Martin
Published: September 2018

The notion of responsible innovation suggests that innovators carry additional responsibilities (to society, stakeholders, users) beyond those commonly suggested. In this paper, we will discuss the meaning of these novel responsibilities focusing on two philosophical problems of attributing such responsibilities to innovators. The first is the allocation of responsibilities to innovators. Innovation is a process that involves a multiplicity of agents and unpredictable, far-reaching causal chains from innovation to social impacts, which creates great uncertainty. A second problem is constituted by possible trade-offs between different kinds of responsibility. It is evident that attributing backward-looking responsibility for product failures diminishes the willingness to learn about such defects and to take forward-looking responsibility. We will argue that these problems can be overcome by elaborating what it is exactly that innovators are responsible for. In this manner, we will distinguish more clearly between holding responsible and taking responsibility. This opens a space for ‘supererogatory’ responsibilities. Second, we will argue that both innovation processes and outcomes can be objects of innovators’ responsibility. Third, we will analyze different kinds of responsibility (blameworthiness, accountability, liability, obligation and virtue) and show that the functions of their attribution are not necessarily contradictory. Based on this conceptual refinement, we will argue that accountability, responsibility-as-virtue and the willingness to take responsibility are crucial for responsible innovation.
Effect of Dung Quantity and Quality on Greenhouse Gas Fluxes From Tropical Pastures in Kenya
Authors: Zhu Yuhao , Merbold Lutz , Pelster David , Diaz‐Pines Eugenio , Wanyama George Nandhoka , Butterbach‐Bahl Klaus
Published: September 2018

To improve estimates of agricultural greenhouse gas emissions in sub‐Saharan Africa, we measured over six individual periods of 25–29 days fluxes of methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) with subdaily time resolution from dung patches of different quality (C/N ratio: 23–41) and quantity (0.5 and 1.0 kg) on a Kenyan rangeland during dry and wet seasons. Methane emissions peaked following dung application, whereas N2O and CO2 fluxes from dung patches were similar to fluxes from rangeland soils receiving no N additions. Greenhouse gas emissions scaled linearly with dung quantity during both seasons. Dung with a low (23) C/N ratio produced up to 10 times more CH4 than dung with a high (41) C/N ratio. Overall, CH4 emission factors (EFs) ranged from 0.001 to 0.042%, lower than those derived in temperate regions. Cumulative CO2 and N2O emissions were similar for all treatments across the different seasons. The N2O EF ranged from 0 to 0.01%, less than 1% of the Intergovernmental Panel on Climate Change Tier 1 default EF (2%) for N2O emissions from dung and urine patches, likely because of the low dung N content (9.7–16.5 g N kg−1 dry matter). However, these results were consistent with the updated cattle dung EF (0.2%) developed for Kenya in 2016/2017 (EF database ID# 422665). In view of the wide range of climates, soils, and management practices across sub‐Saharan Africa, development of robust GHG EFs from dung patches for SSA requires additional studies.
Changes in Irrigation Practices Likely Mitigate Nitrous Oxide Emissions From California Cropland
Authors: Deng Jia , Guo Lei , Salas William , Ingraham Pete , Charrier‐Klobas Jessica G. , Frolking Steve , Li Changsheng
Published: September 2018

Crop production with intensive nitrogen (N) application is an important source of atmospheric nitrous oxide (N2O). However, there remains large uncertainty in quantifying cropland N2O emissions and their mitigation potential, especially in regions where cropping systems and farming management practices are highly diverse. Because N2O production in soils is tightly linked to N application rate and type, soil moisture, and oxygen status, improving irrigation is a potential strategy for N2O mitigation. We applied a process‐based biogeochemical model, DeNitrification‐DeComposition, to evaluate the influence of irrigation management on N2O emissions from California cropland, where cropping systems are extremely diverse and irrigation management has changed rapidly. We constructed a database containing data on weather, crop types and areas, soil properties, and farming management practices and predicted N2O emissions from California cropland under four typical irrigation methods (surface gravity, sprinkler, drip, and subsurface drip). We also assessed impact on N2O emissions of large‐scale changes in irrigation management experienced in California from 2001 to 2010 that was driven by the demand of reducing water use in agriculture. Simulations under different irrigation methods indicated that drip and subsurface drip irrigation reduced N2O emissions by 55% and 67%, respectively, compared to surface gravity irrigation. We estimated baseline N2O emissions from California cropland as 7.94 × 103 metric ton (MT) N/year under actual irrigation management in 2002. The large‐scale changes in irrigation management likely reduced N2O emissions by 7.3% from 2001 to 2010. This study showed the potential for reducing N2O emissions by using low‐volume irrigation.
Eigenmodes of the Transverse Alfvénic Resonator at the Plasmapause: A Van Allen Probes Case Study
Authors: Mager Pavel N. , Mikhailova Olga S. , Mager Olga V. , Klimushkin Dmitri Yu.
Published: September 2018

A Pc4 ultralow frequency wave was detected at spacecraft B of the Van Allen Probes at the plasmapause. A distinctive feature of this wave is the strong periodical modulation of the wave. It is assumed that this modulation is a beating of oscillations close in frequency: at least two harmonics with frequencies of 15.3 and 13.6 MHz are found. It is shown that these harmonics can be the eigenmodes of the transverse resonator at the local maximum of the Alfvén velocity. In addition, the observed wave was in a drift resonance with energetic 80‐keV protons and could be generated by an unstable bump on tail distribution of protons simultaneously observed with the wave. The estimate of the azimuthal wave number m made from the drift resonance condition gives a value of about −100, that is, it is a westward propagating azimuthally small‐scale wave.
The Effect of Barotropic and Baroclinic Tides on Three‐Dimensional Coastal Dispersion
Authors: Suanda Sutara H. , Feddersen Falk , Spydell Matthew S. , Kumar Nirnimesh
Published: September 2018

The effects of barotropic and baroclinic tides on three‐dimensional (3‐D) coastal dispersion are examined with realistic, 200‐m horizontal resolution simulations of the Central Californian continental shelf during upwelling. Over multiple tidal cycles, the horizontal relative dispersion and vertical dispersion of 3‐D drifters are similar between simulations with no tides and with barotropic tides. In contrast, baroclinic tides, which dissipate across the shelf and induce vertical mixing, result in a factor of 2–3 times larger horizontal and vertical dispersion. The increase in horizontal dispersion with vertical mixing is qualitatively consistent with weak‐mixing shear dispersion. Without shear dispersion, horizontal dispersion of surface‐trapped (2‐D) drifters was similar in all simulations. However, 2‐D drifter trajectory differences relative to no tide simulations are 3–4 times larger with baroclinic tides than barotropic tides alone. These results demonstrate the need to include baroclinic tides and 3‐D tracking for coastal passive tracer dispersion.
Mass Composition of the Escaping Flux at Mars: MEX Observations
Authors: Rojas‐Castillo D. , Nilsson H. , Stenberg Wieser G.
Published: September 2018

Using more than 7 years of ion measurements from the ASPERA‐3/IMA instrument onboard the Mars Express mission, we analyze the mass composition of the two main outflowing heavy ion species O
and O+. Using an improved multispecies fitting technique, we discriminate the molecular from atomic oxygen ion population. We find that the low‐energy ions (3.2–100 eV) dominate the heavy ion population downstream of the induced magnetospheric boundary, where the mean ratio of O
relative to O+ is 0.76 (averaged over the low‐energy range and all observed directions). The spatial distribution of the O
/O+ ratio for the near‐Mars environment shows that very close to the planet O
is somewhat more abundant in part of the dayside. The same trend is even clearer in the central tail up to distances of 1.2RM from the center of the tail. In contrast, O+ is more abundant in the terminator region and the mantle just inside the induced magnetospheric boundary. O+ is typically more abundant in the magnetosheath.
The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox
Authors: Sorba A. M. , Achilleos N. A. , Guio P. , Arridge C. S. , Sergis N. , Dougherty M. K.
Published: September 2018

Periodic variations have been observed in many field and particle properties in Saturn's magnetosphere, modulated at a period close to the planetary rotation rate. Magnetic field observations by Cassini's magnetometer instrument suggest that in the outer magnetosphere (beyond ∼12 Saturn radii) Saturn's current sheet is periodically displaced with respect to the rotational equator, to a first approximation acting as a rotating, tilted disk. This manifests as a “flapping” mode when observed by the spacecraft. Recent studies suggest the magnetosphere also has a “breathing” mode, expanding and contracting with a period close to the planetary rotation rate. We model these two modes in tandem by combining a global, geometrical model of a tilted and rippled current sheet with a local, force‐balance model of Saturn's magnetodisk, accounting for the magnetospheric size and hot plasma content. We simulate the breathing behavior by introducing an azimuthal dependence of the system size. We fit Cassini magnetometer data acquired on equatorial orbits from 23 October to 17 December 2009 (Revs 120–122), close to Saturn equinox, in order that seasonal effects on the current sheet are minimized. We find that our model characterizes well the amplitude and phase of the oscillations in the data, for those passes that show clear periodic signatures in the field. In particular, the Bθ (meridional) component can only be characterized when the breathing mode is included. This study introduces calculations for an oscillating boundary, which provide a basis for understanding the complex relationship between current sheet dynamics and the periodic field perturbations.
First Observations of Recurring HF‐Enhanced Topside Ion Line Spectra Near the Fourth Gyroharmonic
Authors: Rexer Theresa , Gustavsson Björn , Leyser Thomas , Rietveld Michael , Yeoman Tim , Grydeland Tom
Published: September 2018

We present first incoherent scatter radar observations of systematically recurring, high‐frequency (HF)‐enhanced ion line spectra at the topside F‐region ionosphere, during magnetic field aligned HF pumping in an O‐mode polarization. The European Incoherent Scatter UHF radar was directed in magnetic zenith on 9–11 March 2016 while stepping the pump frequency across the double resonance of the fourth harmonic of the electron gyrofrequency and the local upper hybrid frequency, in a 3‐min‐on, 3‐min‐off pump cycle. Topside and bottomside enhancements occur at the respective plasma resonance altitude and seem to be asymmetrically conditioned by the relative proximity of the pump frequency to the double resonance frequency. Further, the topside HF‐induced ion line enhancements predominantly appear while the pump frequency is just below the double resonance frequency and only simultaneous to strong bottomside enhancements. A powerful, HF radio wave in O‐mode, transmitted in the direction of magnetic zenith is reflected a few kilometers below the plasma resonance altitude, where the pump frequency is equal to the local plasma frequency, on the bottomside F‐region in the ionosphere. Transionospheric propagation of the pump wave outside the radio window can be facilitated by density striations in the plasma, and we consider, in detail, the possible mechanisms proposed for propagation outside the standard radio window.
MMS, Van Allen Probes, GOES 13, and Ground‐Based Magnetometer Observations of EMIC Wave Events Before, During, and After a Modest Interplanetary Shock
Authors: Engebretson M. J. , Posch J. L. , Capman N. S. S. , Campuzano N. G. , Bělik P. , Allen R. C. , Vines S. K. , Anderson B. J. , Tian S. , Cattell C. A. , Wygant J. R. , Fuselier S. A. , Argall M. R. , Lessard M. R. , Torbert R. B. , Moldwin M. B. , Hartinger M. D. , Kim H. , Russell C. T. , Kletzing C. A. , Reeves G. D. , Singer H. J.
Published: September 2018

The stimulation of electromagnetic ion cyclotron (EMIC) waves by a magnetospheric compression is perhaps the closest thing to a controlled experiment that is currently possible in magnetospheric physics, in that one prominent factor that can increase wave growth acts at a well‐defined time. We present a detailed analysis of EMIC waves observed in the outer dayside magnetosphere by the four Magnetosphere Multiscale (MMS) spacecraft, Van Allen Probe A, and GOES 13 and by four very high latitude ground magnetometer stations in the western hemisphere before, during, and after a modest interplanetary shock on 14 December 2015. Analysis shows several features consistent with current theory, as well as some unexpected features. During the most intense MMS wave burst, which began ~ 1 min after the end of a brief magnetosheath incursion, independent transverse EMIC waves with orthogonal linear polarizations appeared simultaneously at all four spacecraft. He++ band EMIC waves were observed by MMS inside the magnetosphere, whereas almost all previous studies of He++ band EMIC waves observed them only in the magnetosheath and magnetopause boundary layers. Transverse EMIC waves also appeared at Van Allen Probe A and GOES 13 very near the times when the magnetic field compression reached their locations, indicating that the compression lowered the instability threshold to allow for EMIC wave generation throughout the outer dayside magnetosphere. The timing of the EMIC waves at both MMS and Van Allen Probe A was consistent with theoretical expectations for EMIC instabilities based on characteristics of the proton distributions observed by instruments on these spacecraft.
Absolute Stress Fields in the Source Region of the 1992 Landers Earthquake
Authors: Terakawa Toshiko , Hauksson Egill
Published: September 2018

Earthquake focal mechanisms are often inverted to obtain the deviatoric stress field. Because shear stress is equal to the frictional strength of the fault at the time of an earthquake, six components of the absolute stress tensor at the hypocenter can be obtained from a focal mechanism by combining deviatoric stress fields with the Coulomb failure criterion. For a data set of focal mechanisms determined for southern California earthquakes, including the 1992 Landers earthquake sequence, we calculated the absolute stress tensors at their hypocenters using a standard intrinsic friction coefficient under three pore pressure conditions, parameterized by the reference pore pressure at the optimally oriented faults to the stress field. Three absolute stress fields were obtained for southern California immediately before the Landers main shock by applying each data set of the stress tensors to an inversion scheme based on Bayesian statistical inference and Akaike's Bayesian Information Criterion. The coseismic stress field was calculated to obtain the absolute stress fields immediately after the main shock. The variations of the coseismic stress rotation were related to the reference pore pressure. Comparing this relation with that obtained through stress inversion, we determined the absolute stress field and the most plausible reference pore pressure to be hydrostatic. On average, the maximum shear stresses immediately before the main shock were 44 ± 15 and 79 ± 24 MPa at depths of 5 and 10 km, respectively. Earthquakes on the off‐plate boundary faults in southern California occur on faults that are loaded by Anderson‐Byerlee stress conditions.
Understanding the Effects of Polar Mesospheric Clouds on the Environment of the Upper Mesosphere and Lower Thermosphere
Authors: Siskind David E. , Merkel A. W. , Marsh D. R. , Randall C. E. , Hervig M. E. , Mlynczak M. G. , Russell III J. M.
Published: September 2018

This study focuses on the effects of polar mesospheric cloud (PMC) formation on the chemical environment of the mesosphere and lower thermosphere. Of specific interest is how the dehydration due to mesospheric ice particle formation leads to significant seasonal decreases in the atomic hydrogen near the mesopause at middle to high latitudes. Using a three‐dimensional whole atmosphere coupled chemistry/dynamics model, we simulate the effects of this dehydration, and via comparisons with three data sets taken from two NASA satellites, we quantify the perturbations to atomic hydrogen and water vapor. We also identify a local ozone maximum that results from the PMC‐induced decrease in atomic hydrogen. Further, the large interannual variability in the onset of the Southern Hemisphere PMC season correlates well with the interannual variability of early summer atomic hydrogen at 95 km. Since the PMC onset is known to be controlled by interannual variations in the Southern Hemisphere stratospheric polar vortex, this correlation indicates a coupling between the stratosphere and the chemistry of the mesosphere and lower thermosphere. Finally, our model results suggest that the seasonal biteout in atomic hydrogen propagates up into the thermosphere and to lower latitudes. This raises the intriguing possibility that PMC formation might play a role in modulating the escape of hydrogen from the atmosphere.
Chlorate/Fe‐Bearing Phase Mixtures as a Possible Source of Oxygen and Chlorine Detected by the Sample Analysis at Mars Instrument in Gale Crater, Mars
Authors: Hogancamp J. V. , Sutter B. , Morris R. V. , Archer P. D. , Ming D. W. , Rampe E. B. , Mahaffy P. , Navarro‐Gonzalez R.
Published: September 2018

Oxygen and HCl gas releases detected by the Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover in several Gale Crater samples have been attributed to the thermal decomposition of perchlorates and/or chlorates. Previous experimental studies of perchlorates mixed with Fe‐bearing phases explained some but not all of the evolved oxygen releases and cannot explain the HCl releases. The objective of this paper was to evaluate the oxygen and HCl releases of chlorates and chlorate/Fe phase mixtures in experimental studies and SAM evolved gas analysis data sets. Potassium, magnesium, and sodium chlorate were independently mixed with hematite, magnetite, ferrihydrite, and palagonite and analyzed in a thermal evolved gas analyzer configured to operate similarly to the SAM instrument. Fe phases depressed the chlorate decomposition temperature 3–214 °C and consumed up to 75% of the evolved oxygen from chlorate decomposition. Chlorate/Fe phase mixtures have oxygen and HCl releases consistent with some samples analyzed by SAM. Reported oxychlorine abundances based on calculations using oxygen detected by SAM could be minimum values because Fe phases consume evolved oxygen. The results of this work demonstrate that chlorates could be present in the Martian soil and that oxygen and HCl release temperatures could be used to constrain which chlorate cation species are present in samples analyzed by SAM. Knowledge of which chlorates may be present in Gale Crater creates a better understanding of the detectability of organics by evolved gas analysis, habitability potential, and the chlorine cycle on Mars.
Salt Marsh Loss Affects Tides and the Sediment Budget in Shallow Bays
Authors: Donatelli Carmine , Ganju Neil Kamal , Zhang Xiaohe , Fagherazzi Sergio , Leonardi Nicoletta
Published: September 2018

The current paradigm is that salt marshes and their important ecosystem services are threatened by global climate change; indeed, large marsh losses have been documented worldwide. Morphological changes associated with salt marsh erosion are expected to influence the hydrodynamics and sediment dynamics of coastal systems. Here the influence of salt marsh erosion on the tidal hydrodynamics and sediment storage capability of shallow bays is investigated. Hydrodynamics, sediment transport, and vegetation dynamics are simulated using the numerical framework Coupled Ocean‐Atmosphere‐Wave‐Sediment Transport in the Barnegat Bay‐Little Egg Harbor system, USA. We show that salt marsh erosion influences the propagation of tides into back‐barrier basins, reducing the periodic inundation and sediment delivery to marsh platforms. As salt marshes erode, the sediment trapping potential of marsh platforms decreases exponentially. In this test case, up to 50% of the sediment mass trapped by vegetation is lost once a quarter of the marsh area is eroded. Similarly, without salt marshes the sediment budget of the entire bay significantly declines. Therefore, a positive feedback might be triggered such that as the salt marsh retreats the sediment storage capacity of the system declines, which could in turn further exacerbate marsh degradation.
Introducing Finer Grains Into Bedload: The Transition to a New Equilibrium
Authors: Dudill Ashley , Lafaye de Micheaux Hugo , Frey Philippe , Church Michael
Published: September 2018

Simplified experiments on fine grain inputs to a coarse bed in mobile equilibrium were undertaken in a small, steep, narrow flume using spherical glass particles to study the influence upon the channel response of the size ratio between the bed (Dc) and the input fines (Df). Size ratios (Dc/Df) between 7.14 and 1.25 were tested, with a constant flow and coarse sediment feed rate and a variety of fine and total feed rates. Transition to a new, two‐size equilibrium occurs through slope adjustment (aggradation/degradation), accompanying a change in sediment mobility created by the addition of the fine material. Previous work has documented superior mobility following a fine grain input; the present experiments identify limits of this behavior related to the fine grain size, the proportion of fines introduced, and the total sediment supply. The mechanistic reasons for these limits are examined with respect to the grain sorting behavior, leading to the development (or not) of a quasi‐static layer of the fine material at the base of the transport layer. Despite the variation in bed slope response depending upon these factors, the slope transitions consistently follow an exponential profile.
North Atlantic Midlatitude Surface‐Circulation Changes Through the Plio‐Pleistocene Intensification of Northern Hemisphere Glaciation
Authors: Bolton Clara T. , Bailey Ian , Friedrich Oliver , Tachikawa Kazuyo , de Garidel‐Thoron Thibault , Vidal Laurence , Sonzogni Corinne , Marino Gianluca , Rohling Eelco J. , Robinson Marci M. , Ermini Magali , Koch Mirjam , Cooper Matthew J. , Wilson Paul A.
Published: September 2018

The North Atlantic Current (NAC) transports warm salty water to high northern latitudes, with important repercussions for ocean circulation and global climate. A southward displacement of the NAC and Subarctic Front, which separate subpolar and subtropical water masses, is widely suggested for the Last Glacial Maximum (LGM) and may have acted as a positive feedback in glacial expansion at this time. However, the role of the NAC during the intensification of Northern Hemisphere glaciation (iNHG) at ~3.5 to 2.5 Ma is less clear. Here we present new records from Integrated Ocean Drilling Program Site U1313 (41°N) spanning ~2.8–2.4 Ma to trace the influence of Subarctic Front waters above this mid‐latitude site. We reconstruct surface and permanent pycnocline temperatures and seawater δ18O using paired Mg/Ca‐δ18O measurements on the planktic foraminifers Globigerinoides ruber and Globorotalia crassaformis and determine abundances of the subpolar foraminifer Neogloboquadrina atlantica. We find that the first significant glacial incursions of Subarctic Front surface waters above Site U1313 did not occur until ~2.6 Ma. At no time during our study interval was (sub)surface reorganization in the midlatitude North Atlantic analogous to the LGM. Our findings suggest that LGM‐like processes sensu stricto cannot be invoked to explain interglacial‐glacial cycle amplification during iNHG. They also imply that increased glacial productivity at Site U1313 during iNHG was not only driven by southward deflections of the Subarctic Front. We suggest that nutrient injection from cold‐core eddies and enhanced glacial dust delivery may have played additional roles in increasing export productivity in the midlatitude North Atlantic from 2.7 Ma.
A novel fluorescent probe with red emission and a large Stokes shift for selective imaging of endogenous cysteine in living cells
Authors: Chen Dugang , Long Zi , Dang Yecheng , Chen Li
Published: September 2018

A new probe ANT selectively mapped endogenous Cys in living cells with bright red-emission and a large Stokes shift.
Efficient in situ gene delivery via PEG diacrylate matrices
Authors: Shrimali Paresh , Peter Mathew , Singh Archana , Dalal Neha , Dakave Suresh , Chiplunkar Shubhada V. , Tayalia Prakriti
Published: September 2018

Cryogels of PEGDA support cell growth, and those of PEGDA–GELMA allow only cell attachment but no virus retention while those of PEGDA–PLL enhance transduction via the colocalization of cells and viruses.
A modular assembly pH-sensitive charge reversal siRNA delivery system
Authors: Sun Qiong , Tang Chunming , Su Zhigui , Du Junjie , Shang Yunkai , Xue Lingjing , Zhang Can
Published: September 2018

Cationic lipids and polymers are the most common non-viral vectors for siRNA delivery; however, their intense positively charged character may give rise to serum-triggered aggregation, immune activation, inflammation stimulation and grievous toxicity.
LY2874455 potently inhibits FGFR gatekeeper mutants and overcomes mutation-based resistance
Authors: Wu Daichao , Guo Ming , Min Xiaoli , Dai Shuyan , Li Meixiang , Tan Sijie , Li Guoqing , Chen Xiaojuan , Ma Yao , Li Jun , Jiang Longying , Qu Lingzhi , Zhou Zhan , Chen Zhuchu , Chen Lin , Xu Guangyu , Chen Yongheng
Published: September 2018

LY2874455 can avoid a steric clash with the mutated gatekeeper residue in FGFR4.
A high pressure Raman study on confined individual iodine molecules as molecular probes of structural collapse in the AlPO4-5 framework
Authors: Chen Shuanglong , Yao Zhen , Lv Hang , Dong Enlai , Yang Xibao , Liu Ran , Liu Bingbing
Published: September 2018

The individual iodine molecules in the channels of AlPO4-5 can be regarded as molecular probes to detect its structural collapse.
Non-noble metals applied to solar water splitting
Authors: Yi Sha-Sha , Zhang Xin-Bo , Wulan Ba-Ri , Yan Jun-Min , Jiang Qing
Published: September 2018

The generation of hydrogen (H2) induced by solar water splitting over semiconductors has been regarded as one of the most promising strategies for providing clean and renewable energy sources for future energy sustainability.
Fullerene derivative anchored SnO2 for high-performance perovskite solar cells
Authors: Liu Kuan , Chen Shuang , Wu Jionghua , Zhang Huiyin , Qin Minchao , Lu Xinhui , Tu Yingfeng , Meng Qingbo , Zhan Xiaowei
Published: September 2018

A fullerene derivative C9 with anchoring hydroxyl groups on the long side chain is used to modify the surface of SnO2 in planar heterojunction perovskite solar cells, which exhibit high efficiency up to 21.3% with negligible hysteresis and good device stability.
A UV digital micromirror spectrometer for dispersive AFS: spectral interference in simultaneous determination of Se and Pb
Authors: Tao Chen , Li Chunsheng , Li Yingchao , Wang Hongxia , Zhang Yaru , Zhou Zhiheng , Mao Xuefei , Ma Zhenyu , Tian Di
Published: September 2018

Hollow cathode lamps (HCLs) are excitation light sources commonly used in hydride generation atomic fluorescence spectrometry (HG-AFS).
Self-assembly of rare octanuclear quad(double-stranded) cluster helicates showing slow magnetic relaxation and the magnetocaloric effect
Authors: Yao Min-Xia , Cai Li-Zheng , Deng Xiao-Wei , Zhang Wei , Liu Sui-Jun , Cai Xu-Min
Published: September 2018

Four rare structurally novel octanuclear quad(double-strands) cluster helicates containing Ln8 polyhedron cores have been synthesized. Magnetic studies show that the Gd derivative exhibits the magnetocaloric effect and the Dy derivative shows slow magnetic relaxation under zero dc field.
C-Alkylation of N-alkylamides with styrenes in air and scale-up using a microwave flow reactor
Authors: Barham Joshua P. , Tamaoki Souma , Egami Hiromichi , Ohneda Noriyuki , Okamoto Tadashi , Odajima Hiromichi , Hamashima Yoshitaka
Published: September 2018

C-Alkylation of N-alkylamides with styrenes is reported, proceeding in ambient air/moisture to give arylbutanamides and other pharmaceutically-relevant scaffolds in excellent mass balance.
Stimuli-responsive perallyloxycucurbit[6]uril-based nanoparticles for selective drug delivery in melanoma cells
Authors: Cheng Qian , Li Shengke , Sun Chen , Yue Ludan , Wang Ruibing
Published: September 2018

Perallyloxycucurbit[6]uril based nanoparticles exhibited selective payload release in melanoma cells upon UVA irradiation.
Manipulating the mechanical properties of biomimetic hydrogels with multivalent host–guest interactions
Authors: Yang Boguang , Wei Zi , Chen Xiaoyu , Wei Kongchang , Bian Liming
Published: September 2018

Biomimetic hydrogels with multivalent host–guest interactions as reversible crosslinks provide not only energy storage capacity, but also energy dissipation capacity to the dually crosslinked networks.
Recent advances of dicyano-based materials in biology and medicine
Authors: Zhang Weijie , Huo Fangjun , Yin Caixia
Published: September 2018

We highlight the development of dicyano-based fluorescent materials in biology and medicine.
Design of p-type transparent conducting oxides Sn2GeO4 by an ab initio evolutionary structure search
Authors: Yu Jun , Wang Junjie , Kumar Mukesh , Umezawa Naoto , Abe Hideki
Published: September 2018

In contrast to n-type transparent conducting oxides (TCOs), very few p-type TCOs have been discovered to date.
A self-powered solar-blind photodetector based on a MoS2/β-Ga2O3 heterojunction
Authors: Zhuo Ranran , Wu Di , Wang Yuange , Wu Enping , Jia Cheng , Shi Zhifeng , Xu Tingting , Tian Yongtao , Li Xinjian
Published: September 2018

High-performance self-powered solar-blind photodetector based on a MoS2/β-Ga2O3 heterojunction was demonstrated, which exhibits excellent solar-blind photoresponse properties.