bluuebunny/crossref_metadata_2025 huggingface dataset:
A simple nonlinear H∞ control design method: Polynomial nonlinear control
Authors: Liu Lijun
Published: September 2018

The question of how to construct a noniterative analytical solution for nonlinear H∞ control is still an open challenge. This paper focuses on this challenge and proposes a novel simple approach, namely, polynomial nonlinear control, to design a nonlinear H∞ control law without any iteration. Moreover, the solution of PNC is transformed into solvable LMIs. The design of PNC can be carried out in three steps: firstly, expand nonlinear system matrices via Taylor series expansions; secondly, choose and compute design parameters according to the proposed explicit formulas; and thirdly, obtain an analytical control law of PNC by solving an LMI optimization problem. Thus, the algorithm and the computation of PNC are quite simple and straightforward in engineering. In addition, stability and L2 gain for the nonlinear closed‐loop system are also guaranteed by PNC. The numerical simulations show that PNC can improve the control performances including transient responses, disturbance rejection, control effort, and the domain of attraction.
Distributed optimization for a class of high‐order nonlinear multiagent systems with unknown dynamics
Authors: Tang Yutao
Published: September 2018

In this paper, we study a distributed optimization problem for a class of high‐order multiagent systems with unknown dynamics. In comparison with existing results for integrators or linear agents, we need to overcome the difficulties brought by the unknown nonlinearities and the optimization requirement. For this purpose, we employ an embedded control‐based design and first convert this problem into an output stabilization problem. Then, two kinds of adaptive controllers are given for these agents to drive their outputs to the global optimal solution under some mild conditions. Finally, we show that the estimated parameter vector converges to the true parameter vector under some well‐known persistence of excitation condition. The efficacy of these algorithms was verified by a simulation example.
Relative efficiency of unequal cluster sizes in stepped wedge and other trial designs under longitudinal or cross‐sectional sampling
Authors: Girling Alan J.
Published: September 2018

Background: A cluster trial with unequal cluster sizes often has lower precision than one with equal clusters, with a corresponding inflation of the design effect. For parallel group trials, adjustments to the design effect are available under sampling models with a single intracluster correlation. Design effects for equal clusters under more complex scenarios have appeared recently (including stepped wedge trials under cross‐sectional or longitudinal sampling). We investigate the impact of unequal cluster size in these more general settings.

Results: Assuming a linear mixed model with an exchangeable correlation structure that incorporates cluster and subject autocorrelation, we compute the relative efficiency (RE) of a trial with clusters of unequal size under a size‐stratified randomization scheme, as compared to an equal cluster trial with the same total number of observations. If there are no within‐cluster time effects, the RE exceeds that for a parallel trial. In general, the RE is a weighted average of the RE for a parallel trial and the RE for a crossover trial in the same clusters. Existing approximations for parallel designs are extended to the general setting. Increasing the cluster size by the factor (1 + CV2), where CV is the coefficient of variation of cluster size, leads to conservative sample sizes, as in a popular method for parallel trials.

Conclusion: Methods to assess experimental precision for single‐period parallel trials with unequal cluster sizes can be extended to stepped wedge and other complete layouts under longitudinal or cross‐sectional sampling. In practice, the loss of precision due to unequal cluster sizes is unlikely to exceed 12%.
Investigations of Interfacial Electric Field on Reduced‐Graphene‐Oxide‐Supported Molybdenum Oxide @ Silver Phosphate Ternary Hybrid Composite: Highly Efficient Visible‐Light‐Driven Photocatalyst
Authors: Dhanabal Rengasamy , Shafi Parrasseri Muhammed , Arun Thirumurugan , Velmathi Sivan , Hussain Shamima , Bose Arumugam Chandra
Published: September 2018

Reduced graphene oxide supported molybdenum oxide @ silver phosphate (RGO‐MoO3@Ag3PO4) ternary hybrid composite was prepared by simple mixing of RGO supported MoO3 nanorods into Ag3PO4 nanosphere. Upon visible light exposure, the photocatalytic degradation of MB revealed that the 30 wt.% RGO‐MoO3@Ag3PO4 photocatalyst led to 2.9 times higher activities than pure Ag3PO4, 6.2 and 8.7 times compared to RGO‐MoO3 and pure MoO3, respectively. Degradation of MB using 30 wt.% RGO‐MoO3@Ag3PO4 is 2.9 and 15 times higher compared to RhB and MO respectively. The downward band bending of Ag3PO4 at the interface of RGO‐MoO3@Ag3PO4 was investigated based on the electric field formed. The formed electric field at the interface of RGO‐MoO3@Ag3PO4 is found to be 50 mV which avoids the recombination rate of electron‐hole pairs at the interfaces. This formed electric field promotes the higher separation efficiency of electrons‐holes pairs and longer life time of photoexcited electrons in the RGO‐MoO3@Ag3PO4 resulting higher efficiency and stability. RGO act as an electron acceptor and transporter during charge transfer process between MoO3 and Ag3PO4.
Cloud‐based video analytics using convolutional neural networks
Authors: Yaseen Muhammad Usman , Anjum Ashiq , Farid Mohsen , Antonopoulos Nick
Published: September 2018

Object classification is a vital part of any video analytics system, which could aid in complex applications such as object monitoring and management. Traditional video analytics systems work on shallow networks and are unable to harness the power of distributed processing for training and inference. We propose a cloud‐based video analytics system based on an optimally tuned convolutional neural network to classify objects from video streams. The tuning of convolutional neural network is empowered by in‐memory distributed computing. The object classification is performed by comparing the target object with the prestored trained patterns, generating a set of matching scores. The matching scores greater than an empirically determined threshold reveal the classification of the target object. The proposed system proved to be robust to classification errors with an accuracy and precision of 97% and 96%, respectively, and can be used as a general‐purpose video analytics system.
Development and validation of a HPLC with fluorescence detection method to quantify the peanut allergen Ara h 2 in peanut extract and sublingual films
Authors: Jiang Bowen , Ibrahim Ahmed , Martin Russell , Keet Corinne , Mao Hai‐Quan , Hoag Stephen W.
Published: September 2018

A rapid and selective reversed‐phase high‐performance liquid chromatographic method with fluorescence detection was developed for quantitation of the peanut allergen Ara h 2 in peanut extracts and dissolving sublingual films containing peanut extracts. The separation of Ara h 2 from other proteins in the peanut extracts and dosage matrix is a challenging problem, and the separation was optimized using DryLab® software. The high‐performance liquid chromatography method involved a BEH C4 Column running at 52°C for 25 min, with a gradient elution of acetonitrile and water containing 0.1% trifluoroacetic acid. Fluorescence detection was used at an excitation wavelength of 261 nm and emission wavelength of 310 nm. The linearity range was 7.5 to 30 μg/mL, with a calculated detection limit of 1.61 μg/mL and a quantitation limit of 4.89 μg/mL. The validated method was applied to quantitate the amount of Ara h 2 in the sublingual films containing peanut extract, which was designed to desensitize children with peanut allergy. This method was also used to evaluate the accelerated stability of five different formulations of sublingual films and was able to distinguish differences among formulations.
Monitoring of polyphenol mangiferin by liquid chromatography tandem mass spectrometry in rat and its comparative pharmacokinetic study of a single compound, a single botanic extract and multiple botanic extract
Authors: Chang Hsing‐Yi , Hsueh Thomas Y. , Tsai Tung‐Hu
Published: September 2018

The aim of this study is to develop a sensitive, validated specific performance liquid chromatography tandem mass spectrometry method to analysis of spinosin, jujuboside A, jujuboside B, mangiferin, pachymic acid, ferulic aid, and glycyrrhizic acid in herbal preparations. This validated method was further applied to a comparative study on the pharmacokinetics and oral bioavailability of mangiferin following administration of mangiferin (a single compound),Anemarrhenae Rhizomaextracts (a single‐herb extract), and a multiple botanicAnemarrhenae Rhizomaextract. A conscious and freely moving rat model was used for pharmacokinetic study of mangiferin. A parallel study was divided into four treatments to investigate the oral bioavailability of mangiferin, single compound of mangiferin (3 mg/kg, i.v.), mangiferin (38 mg/kg, p.o.), and a single botanicAnemarrhenae Rhizomaextracts (2.85 g/kg, p.o.), and a multiple botanicAnemarrhenae Rhizomaextract (10 g/kg, p.o.). The above oral doses of botanic extract were equivalently to mangiferin (38 mg/kg, p.o.). The pharmacokinetic results demonstrated that the oral bioavailability of mangiferin for the single compound administration (0.6%) was significantly lower than that of both the singleAnemarrhenae Rhizomaextracts (6.2%) and a multiple botanicAnemarrhenae Rhizomaextract (3.0%). This phenomenon may be due to herbal ingredient‐ingredient or botanic‐botanic interactions.
Perovskite Distortion Inverted: Crystal Structures of (A3N)As (A = Mg, Ca, Sr, Ba)
Authors: Stoiber Dominik , Niewa Rainer
Published: September 2018

Powder samples of the compounds (A3N)As (A = Mg, Ca, Sr, Ba) were prepared by reacting the respective alkaline earth metal nitrides and arsenic in nickel ampoules. (Mg3N)As crystallizes in a cubic unit cell (space group Pm3m, no. 221) with inverse perovskite structure. The analogous compounds of calcium, strontium, and barium crystallize in an orthorhombic unit cell (space group Pnma, no. 62) as distorted inverse perovskites in the GdFeO3 structure type. The degree of distortion was quantified based on a newly developed vectorial comparison of the atomic sites of coordination polyhedra with the ideal positions (PolyDis). Based on this analysis, the distortion increases with the size of the alkaline earth metal cation.
Trilling Formation in the EuAuGe type Gallides REAuGa with RE = La, Ce, Pr, Nd, and Sm
Authors: Schubert Lea , Hoffmann Rolf‐Dieter , Heletta Lukas , Pöttgen Rainer
Published: September 2018

The equiatomic gallides REAuGa (RE = La, Ce, Pr, Nd, Sm) were synthesized from the elements by arc‐melting. Small single crystals were grown by slowly cooling the samples from 1073 K to room temperature at a rate of 3 K·h–1. The REAuGa structures were reinvestigated from single‐crystal X‐ray diffractometer data. The five gallides adopt the non‐centrosymmetric EuAuGe type structure, space group Imm2, a superstructure variant of KHg2. The symmetry reductions lead to the formation of trillings and inversion twins. The domain ratios were precisely determined from the single crystal data. The striking structural motifs of the REAuGa structures are slightly puckered Au3Ga3 layers with strong covalent Au–Ga bonding. Stacking of these layers in AA′ sequence (A and A′ are related by mirror planes) leads to weak Au–Au (aurophilic bonding) and Ga–Ga interlayer interactions (319 and 283 pm in SmAuGa). Temperature dependent magnetic susceptibility measurements revealed Curie–Weiss behavior for CeAuGa and NdAuGa, whereas SmAuGa exhibits the typical van Vleck paramagnetism caused by contributions of the excited states. Antiferromagnetic ground states were observed for CeAuGa, NdAuGa, and SmAuGa below the respective Néel temperatures of 2.8, 9.5 and 24.1 K. LaAuGa is Pauli paramagnetic.
Realizing the full potential of precision health: The need to include patient-reported health behavior, mental health, social determinants, and patient preferences data
Authors: Glasgow Russell E. , Kwan Bethany M. , Matlock Daniel D.
Published: September 2018

Precision health and big data approaches have great potential, yet such benefits will be realized only when social and behavioral determinants of health and patient preferences are combined with genomic information. Literature review and co-author experiences informed this commentary. Validated health behavior, mental health, and patient preference measures were collected and summarized in real time. Integration of such data into existing data sets will advance precision health, patient-centered care, research, and policy.
Toward high-power nonlinear fiber amplifier
Authors: Zhang Hanwei , Zhou Pu , Xiao Hu , Leng Jinyong , Tao Rumao , Wang Xiaolin , Xu Jiangming , Xu Xiaojun , Liu Zejin
Published: September 2018

Stimulated Raman scattering (SRS) effect is considered to be one of the main obstacles for power scaling in general-type fiber lasers. Different from previous techniques that aim at suppressing SRS, nonlinear fiber amplifier (NFA), which manipulates and employs the SRS for power scaling in rare-earth-doped fiber, is under intensive research in recent years. In this paper, the authors will present an all-round study on this new kind of high-power fiber amplifier. A theoretical model is proposed based on the rate equation and amplified spontaneous emission (ASE), with random noise taken into account. By numerical solving of the theoretical model, the power scaling potential, heat analysis and advantages in suppressing the undesired backscattering light are quantificationally analyzed for the first time. Then two different types of high-power NFAs are demonstrated individually. Firstly, a laser diode pumped NFA has reached kilowatt output power, and the results agree well with theoretical predictions. Secondly, a tandem-pumped NFA is proposed for the first time and validated experimentally, in which 1.5 kW output power has been achieved. The authors also briefly discuss several new issues relating to the complex nonlinear dynamics that occur in high-power NFAs, which might be interesting topics for future endeavors.
WTO REGULATION OF TRANSNATIONAL PRIVATE AUTHORITY IN GLOBAL GOVERNANCE
Authors: Du Ming
Published: September 2018

Following the proliferation of private standards in the global supply chain trade, it has become clear that these can have adverse effects on international commerce and world welfare in the same way that government-imposed mandatory regulations do. However, the scope of the obligation of WTO Members in relation to the regulation of private standards remains vague and open to divergent interpretations under WTO law. This article starts from the premise that the debate should move beyond the search for a reasonable interpretation of relevant WTO disciplines and instead begin to consider normative questions concerning the legitimacy and accountability of transnational private regulation in global governance and the potential role of the WTO in regulating such private authority. The article explores what justifies the role of the WTO, a multilateral intergovernmental organization, in regulating transnational private standards and how a regulatory mechanism might be designed and implemented in practice.
Streamlining grommet pathways for otitis media with effusion and hearing loss in children: our experience
Authors: McLaren O , Toll E C , Easto R , Willis E , Harris S , Rainsbury J
Published: September 2018

Background

Grommet insertion is a common surgical procedure in children. Long waiting times for grommet insertion are not unusual. This project aimed to streamline the process by introducing a pathway for audiologists to directly schedule children meeting National Institute for Health and Care Excellence Clinical Guideline 60 (‘CG60’) for grommet insertion.

Method and results

A period from June to November 2014 was retrospectively audited. Mean duration between the first audiology appointment and grommet insertion was 294.5 days (median = 310 days). Implementing the direct-listing pathway reduced the duration between first audiology appointment and grommet insertion (mean = 232 days; median = 231 days). There has been a reduction in the time between the first audiology appointment and surgery (mean difference of 62.5 days; p = 0.024), and a reduction in the time between second audiology appointment and surgery (28 days; p = 0.009).

Conclusion

Direct-listing pathways for grommet insertion can reduce waiting times and expedite surgery. Implementation involves a simple alteration of current practice, adhering to National Institute for Health and Care Excellence Clinical Guideline 60. The ultimate decision regarding surgery still rests with ENT specialists.
Finite-Larmor-radius equilibrium and currents of the Earth’s flank magnetopause
Authors: Cerri S. S.
Published: September 2018

We consider the one-dimensional equilibrium problem of a shear-flow boundary layer within an ‘extended-fluid model’ of a plasma that includes the Hall and the electron pressure terms in Ohm’s law, as well as dynamic equations for anisotropic pressure for each species and first-order finite-Larmor-radius (FLR) corrections to the ion dynamics. We provide a generalized version of the analytic expressions for the equilibrium configuration given in Cerri et al., (Phys. Plasmas, vol. 20 (11), 2013, 112112), highlighting their intrinsic asymmetry due to the relative orientation of the magnetic field $\boldsymbol{B}$, $\boldsymbol{b}=\boldsymbol{B}/|\boldsymbol{B}|$, and the fluid vorticity $\unicode[STIX]{x1D74E}=\unicode[STIX]{x1D735}\times \boldsymbol{u}$ (‘$\unicode[STIX]{x1D74E}\boldsymbol{b}$ asymmetry’). Finally, we show that FLR effects can modify the Chapman–Ferraro current layer at the flank magnetopause in a way that is consistent with the observed structure reported by Haaland et al., (J. Geophys. Res. (Space Phys.), vol. 119, 2014, pp. 9019–9037). In particular, we are able to qualitatively reproduce the following key features: (i) the dusk–dawn asymmetry of the current layer, (ii) a double-peak feature in the current profiles and (iii) adjacent current sheets having thicknesses of several ion Larmor radii and with different current directions.
Multiple nutritional factors and thyroid disease, with particular reference to autoimmune thyroid disease
Authors: Rayman Margaret P.
Published: September 2018

Hashimoto's thyroiditis (HT) and Graves’ disease (GD) are examples of autoimmune thyroid disease (AITD), the commonest autoimmune condition. Antibodies to thyroid peroxidase (TPO), the enzyme that catalyses thyroid-hormone production and antibodies to the receptor for the thyroid-stimulating hormone, are characteristic of HT and GD, respectively. It is presently accepted that genetic susceptibility, environmental factors, including nutritional factors and immune disorders contribute to the development of AITD. Aiming to investigate the effect of iodine, iron and selenium in the risk, pathogenesis and treatment of thyroid disease, PubMed and the Cochrane Library were searched for relevant publications to provide a narrative review.Iodine: chronic exposure to excess iodine intake induces autoimmune thyroiditis, partly because highly-iodinated thyroglobulin (Tg) is more immunogenic. The recent introduction of universal salt iodisation can have a similar, although transient, effect.Iron: iron deficiency impairs thyroid metabolism. TPO is a haem enzyme that becomes active only after binding haem. AITD patients are frequently iron-deficient since autoimmune gastritis, which reduces iron absorption and coeliac disease which causes iron loss, are frequent co-morbidities. In two-thirds of women with persistent symptoms of hypothyroidism despite appropriate levothyroxine therapy, restoration of serum ferritin above 100 µg/l ameliorated symptoms.Selenium: selenoproteins are essential to thyroid action. In particular, the glutathione peroxidases remove excessive hydrogen peroxide produced there for the iodination of Tg to form thyroid hormones. There is evidence from observational studies and randomised controlled trials that selenium, probably as selenoproteins, can reduce TPO-antibody concentration, hypothyroidism and postpartum thyroiditis. Appropriate status of iodine, iron and selenium is crucial to thyroid health.
A systematic review of effectiveness and cost-effectiveness of school-based identification of children and young people at risk of, or currently experiencing mental health difficulties
Authors: Anderson Joanna K. , Ford Tamsin , Soneson Emma , Coon Jo Thompson , Humphrey Ayla , Rogers Morwenna , Moore Darren , Jones Peter B. , Clarke Emmet , Howarth Emma
Published: September 2018

Background

Although school-based programmes for the identification of children and young people (CYP) with mental health difficulties (MHD) have the potential to improve short- and long-term outcomes across a range of mental disorders, the evidence-base on the effectiveness of these programmes is underdeveloped. In this systematic review, we sought to identify and synthesise evidence on the effectiveness and cost-effectiveness of school-based methods to identify students experiencing MHD, as measured by accurate identification, referral rates, and service uptake.

Method

Electronic bibliographic databases: MEDLINE, Embase, PsycINFO, ERIC, British Education Index and ASSIA were searched. Comparative studies were included if they assessed the effectiveness or cost-effectiveness of strategies to identify students in formal education aged 3–18 years with MHD, presenting symptoms of mental ill health, or exposed to psychosocial risks that increase the likelihood of developing a MHD.

Results

We identified 27 studies describing 44 unique identification programmes. Only one study was a randomised controlled trial. Most studies evaluated the utility of universal screening programmes; where comparison of identification rates was made, the comparator test varied across studies. The heterogeneity of studies, the absence of randomised studies and poor outcome reporting make for a weak evidence-base that only generate tentative conclusions about the effectiveness of school-based identification programmes.

Conclusions

Well-designed pragmatic trials that include the evaluation of cost-effectiveness and detailed process evaluations are necessary to establish the accuracy of different identification models, as well as their effectiveness in connecting students to appropriate support in real-world settings.
Stopping power of a helium plasma under LTE or NLTE conditions
Authors: González-Gallego Luis , Barriga-Carrasco Manuel D. , Gil Juan Miguel , Rodríguez Rafael , Espinosa Guadalupe
Published: September 2018

In this work, the stopping power of a partially ionized helium plasma due to its free and bound electrons is analyzed for an electron temperature and density in which local thermal equilibrium (LTE) or non-local thermal equilibrium (NLTE) regimes can be possible. In particular by means of collisional-radiative models, the average ionization of the plasma as well as the abundances of different helium species (HeI, HeII, and HeIII) are analyzed in both LTE and NLTE thermodynamic states. The influence of this ionization and of the different ion abundances on the stopping power of the helium plasma is shown to be quite significant. Finally, our theoretical model is compared with experimental results on slowing down of swift argon ions in helium plasma.
Comparison between electroporation and polyfection in pig sperm: efficiency and cell viability implications
Authors: da Silva Zigomar , de Souza Andressa Pereira , Pandolfi José Rodrigo Claudio , da Fonseca Francisco Noé , da Veiga Lima-Rosa Carlos André , Marques Mariana Groke
Published: September 2018

The aim of this study was to optimize protocols for electroporation (EP) and polyfection (PLF) using polyethyleneimine (PEI) for pig sperm transfection and to determine which method was the most efficient. For EP standardization, different voltages, amounts and times of electric pulses were tested using propidium iodide (PI) as reporter. For PLF standardization, different concentrations of fluorescein isothiocyanate (FITC)-labelled PEI (PEI/FITC) were incubated with sperm for different periods of time. Flow cytometry was performed to evaluate the best protocol in terms of cell viability, including cytoplasmic membrane, acrosome, chromatin integrities and mitochondrial potential using the FITC probe, PI, acridine orange (AO) and JC1. Transfections with the plasmid pmhyGENIE-5 were carried out under optimum conditions for each procedure (EP: 500 volts, 500 μs and two pulses; PLF: PEI 0.5 mg/ml and incubation time 10 min). Transfection efficacy was assessed by fluorescence in situ hybridization (FISH). A lower transfection rate was observed for sperm in the control group (17.8%) compared with EP (36.7%), with PLF (76.8%) being the most efficient. These results suggest that the EP and PEI could be an efficient and low cost transfection method for swine sperm. Notably, treated cells showed higher plasmatic the membrane damage (PMD) and/or acrosome damage (AD) indexes, therefore the combination of this procedure with biotechniques that facilitate fecundation (i.e. in vitro fertilization or intracytoplasmic sperm injection) or even inclusion of antioxidant or anti-apoptotic drugs to improve spermatozoa viability would be important.
A novel ILP framework for summarizing content with high lexical variety
Authors: LUO WENCAN , LIU FEI , LIU ZITAO , LITMAN DIANE
Published: September 2018

Summarizing content contributed by individuals can be challenging, because people make different lexical choices even when describing the same events. However, there remains a significant need to summarize such content. Examples include the student responses to post-class reflective questions, product reviews, and news articles published by different news agencies related to the same events. High lexical diversity of these documents hinders the system’s ability to effectively identify salient content and reduce summary redundancy. In this paper, we overcome this issue by introducing an integer linear programming-based summarization framework. It incorporates a low-rank approximation to the sentence-word cooccurrence matrix to intrinsically group semantically similar lexical items. We conduct extensive experiments on datasets of student responses, product reviews, and news documents. Our approach compares favorably to a number of extractive baselines as well as a neural abstractive summarization system. The paper finally sheds light on when and why the proposed framework is effective at summarizing content with high lexical variety.
Consistency and replicability of a pharmacist-led intervention for asthma patients: Italian Medicines Use Review (I-MUR)
Authors: Manfrin Andrea , Krska Janet
Published: September 2018

Aim

This study aimed to assess the consistency and replicability of these process measures during provision of the Italian Medicines Use Review (I-MUR).

Background

Medication review is a common intervention provided by community pharmacists in many countries, but with little evidence of consistency and replicability. The I-MUR utilised a standardised question template in two separate large-scale studies. The template facilitated pharmacists in recording medicines and problems reported by patients, the pharmaceutical care issues (PCIs) they found and actions they took to improve medicines use.

Methods

Community pharmacists from four cities and across 15 regions were involved in the two studies. Patients included were adults with asthma. Medicines use, adherence, asthma problems, PCIs and actions taken by pharmacists were compared across studies to assess consistency and replicability of I-MUR.

Findings

The total number of pharmacists and patients completing the studies was 275 and 1711, respectively. No statistically significant differences were found between the studies in the following domains: patients’ demographic, patients’ perceived problems, adherence, asthma medicines used and healthy living advice provided by pharmacists. The proportion of patients in which pharmacists identified PCIs was similar across both studies. There were differences only in the incidence of non-steroidal anti-inflammatory drug use, the frequency of potential drug-disease interactions and in the types of advice given to patients and GPs.

Conclusions

The use of a standardised template for the I-MUR may have contributed to a degree of consistency in the issues found, which suggests this intervention could have good replicability.
Generic Atmospheric Correction Model for Interferometric Synthetic Aperture Radar Observations
Authors: Yu Chen , Li Zhenhong , Penna Nigel T. , Crippa Paola
Published: September 2018

For mapping Earth surface movements at larger scale and smaller amplitudes, many new synthetic aperture radar instruments (Sentinel‐1A/B, Gaofen‐3, ALOS‐2) have been developed and launched from 2014–2017, and this trend is set to continue with Sentinel‐1C/D, Gaofen‐3B/C, RADARSAT Constellation planned for launch during 2018–2025. This poses more challenges for correcting interferograms for atmospheric effects since the spatial‐temporal variations of tropospheric delay may dominate over large scales and completely mask the actual displacements due to tectonic or volcanic deformation. To overcome this, we have developed a generic interferometric synthetic aperture radar atmospheric correction model whose notable features comprise (i) global coverage, (ii) all‐weather, all‐time useability, (iii) correction maps available in near real time, and (iv) indicators to assess the correction performance and feasibility. The model integrates operational high‐resolution European Centre for Medium‐Range Weather Forecasts (ECMWF) data (0.125° grid, 137 vertical levels, and 6‐hr interval) and continuous GPS tropospheric delay estimates (every 5 min) using an iterative tropospheric decomposition model. The model's performance was tested using eight globally distributed Sentinel‐1 interferograms, encompassing both flat and mountainous topographies, midlatitude and near polar regions, and monsoon and oceanic climate systems, achieving a phase standard deviation and displacement root‐mean‐square (RMS) of ~1 cm against GPS over wide regions (250 by 250 km). Indicators describing the model's performance including (i) GPS network and ECMWF cross RMS, (ii) phase versus estimated atmospheric delay correlations, (iii) ECMWF time differences, and (iv) topography variations were developed to provide quality control for subsequent automatic processing and provide insights of the confidence level with which the generated atmospheric correction maps may be applied.
Physics‐Based Modeling of Earthquake‐Induced Ionospheric Disturbances
Authors: Meng X. , Verkhoglyadova O. P. , Komjathy A. , Savastano G. , Mannucci A. J.
Published: September 2018

To numerically simulate earthquake‐induced ionospheric disturbances, we extend the Wave Perturbation‐Global Ionosphere‐Thermosphere Model, which was originally developed for tsunami‐ionosphere coupling via gravity waves, to the case of earthquake‐ionosphere coupling via acoustic‐gravity waves. The new Wave Perturbation‐Global Ionosphere‐Thermosphere Model represents epicentral crustal movements by a point source specified with the ground motion data from seismic measurements. The model then solves for the neutral atmospheric perturbations generated by spherical acoustic‐gravity waves and the resulting ionospheric plasma perturbations over the epicentral area. We apply the model to simulate the near‐field ionospheric disturbances during two major earthquake events: the 2011 Tohoku‐Oki, Japan, and the 2015 Illapel, Chile, events. To validate the results, we extract receiver‐to‐satellite total electron content perturbations from the simulations and compare them to the corresponding slant total electron content perturbations from Global Positioning System observations. We find good agreement on magnitudes and arrival times between the simulations and observations.
Temporal Variations of Near‐Surface Anisotropy Induced by Hydraulic Fracturing at a Shale Play Site in Southwest China
Authors: Zuo Qiankun , Tang Youcai , Niu Fenglin , Li Guoliang , Chen Haichao , Tao Kai , Chen Benchi
Published: September 2018

Knowledge of the geometric properties of fractures and cracks in a petroleum reservoir is important to reservoir exploitation. When aligned and partially connected, fractures and cracks can act as conduits for fluid flow and thus can significantly increase the permeability of the reservoir. The aligned fractures and cracks, on the other hand, are an effective means to generate seismic anisotropy. In this study, we utilize the seismic data recorded by a vertical array installed in a shallow borehole at a shale play site in southwest China. By applying seismic interferometry to the ambient noise data recorded by 12 three‐component geophones, we extractPandSwaves propagating vertically along the borehole. TheSwaves show up to 20% velocity variations with respect to their polarization directions. Such largeSwave anisotropy can be explained by the horizontal transverse isotropic model and is likely caused by natural fractures that are widely present in the area and align approximately in the NE‐SW direction. During the 13‐day period of hydraulic fracking treatment, we also observe large and systematic temporal variations inSwave velocity, degree ofSwave polarization anisotropy, and fast polarization direction. By comparing our observations with normal strain changes calculated with a half‐space elastic model, we speculate that strain changes induced by hydraulic injection and fracturing are likely to be responsible for the observed temporal variations in seismic anisotropy. As such, seismic interferometry with shallow borehole acquisition might provide an alternative means to monitor hydraulic fracturing and wastewater injection in the future.
Fluid Injection and the Mechanics of Frictional Stability of Shale‐Bearing Faults
Authors: Scuderi Marco M. , Collettini C.
Published: September 2018

Fluid overpressure is one of the primary mechanisms for triggering tectonic fault slip and human‐induced seismicity. This mechanism is appealing because fluid overpressure reduces the effective normal stress, hence favoring fault reactivation. However, upon fault reactivation models of earthquake nucleation suggest that increased fluid pressure should favor stable sliding rather than dynamic failure. Here we describe laboratory experiments on shale fault gouge, conducted in the double direct shear configuration in a true‐triaxial machine. To characterize frictional stability and hydrological properties we performed three types of experiments: (1) stable sliding shear experiments to determine the material failure envelope and permeability, (2) velocity step experiments to determine the rate‐and‐state frictional properties, and (3) creep experiments to study fault slip evolution with increasing pore fluid pressure. The shale gouge shows low frictional strength, μ = 0.28, and permeability, k ~ 10−19 m2 together with a velocity strengthening behavior indicative of aseismic slip. During fault pressurization, we document that upon failure slip velocity remains slow (i.e., v ~ 200 μm/s), not approaching dynamic slip rates. We relate this fault slip behavior to the interplay between the fault weakening induced by fluid pressurization, the strong rate‐strengthening behavior of shales, and the evolution of fault zone structure. Our data show that fault rheology and fault stability is controlled by the coupling between fluid pressure and rate‐and‐state friction parameters.
Crustal Structure and Dynamics of Botswana
Authors: Fadel Islam , van der Meijde Mark , Paulssen Hanneke
Published: September 2018

We present the first nationwide crustal thickness and Vp/Vs maps for Botswana based on the analysis of new P wave receiver functions of NARS‐Botswana network integrated with previous receiver function results in Botswana. Using H‐K analysis, we found crustal thickness values ranging from 34 km for the Okavango Rift Zone to 49 km at the border between the Magondi Belt and the Zimbabwe Craton. For stations with significant sediment cover, a sediment correction was applied based on sequential H‐K stacking. We observed distinct differences for the Kaapvaal craton. The eastern part has a high Vp/Vs ratio typical of a predominantly mafic composition, suggesting lateral extension of the Bushveld mafic complex. On the other hand, the western part with a Vp/Vs ratio of 1.67 is felsic, probably as a result of delamination caused by Proterozoic rifting processes. Further to the west of the Kaapvaal Craton, we found a crustal thickness of 42 km and a Vp/Vs ratio of 1.76 for the Nosop Basin. These values are similar to other cratonic regions in Botswana, suggesting the presence of a buried craton as proposed by previous studies. We confirm a relatively thin crust (∼34–39 km), compared to the rest of Botswana, and high Vp/Vs ratio (∼1.84) underneath the Okavango Rift Zone found by previous receiver function studies. Notably, we also found a relatively thin crust (37 km) and high Vp/Vs ratio (1.84) in central Botswana underneath the Passarge Basin.
The Cassini State of the Moon's Inner Core
Authors: Stys Christopher , Dumberry Mathieu
Published: September 2018

We present a model of the precession dynamics of the Moon that comprises a fluid outer core and a solid inner core. We show that three Cassini states associated with the inner core exist. The tilt angle of the inner core in each of these states is determined by the ratio between the free inner core nutation frequency (ωficn) and the precession frequency Ωp=2π/18.6 year−1. All three Cassini states are possible if |ωficn|>2π/16.4 year−1, but only one is possible otherwise. Assuming that the lowest energy state is favored, this transition marks a discontinuity in the tilt angle of the inner core, transiting from −33° to 17° as measured with respect to the mantle figure axis, where negative angles indicate a tilt toward the orbit normal. Possible Lunar interior density structures cover a range of ωficn, from approximately half to twice as large as Ωp, so the precise tilt angle of the inner core remains unknown, though it is likely large because Ωp is within the resonant band of ωficn. Adopting one specific density model, we suggest an inner core tilt of approximately −17°. Viscoelastic deformations within the inner core and melt and growth at the surface of a tilted inner core, both neglected in our model, should reduce this amplitude. If the inner core is larger than approximately 200 km, it may contribute by as much as a few thousandths of a degree on the observed mantle precession angle of 1.543°.
Effects of Explicit Convection on Land Surface Air Temperature and Land‐Atmosphere Coupling in the Thermal Feedback Pathway
Authors: Sun J. , Pritchard M. S.
Published: September 2018

Simulating and understanding continental temperature extremes is a critical issue in Earth System Modeling. Conventional general circulation models are impaired by imperfect cloud and boundary layer parameterization schemes with implications for potentially unrealistic distributions of atmospheric variables and land‐atmosphere coupling signals. In this study we examine a modern version of Superparameterization (SP) in the Community Atmosphere Model v.5 to examine impacts of SP on the characteristics of land surface air temperature, thermal land‐atmosphere coupling, and the relationship between them. The results show that SP in the Community Atmosphere Model (SPCAM) improves mean land surface air temperature at daily time scales regionally compared to Community Atmosphere Model 5 and better simulates thermal land‐atmosphere coupling (soil moisture‐surface air temperature coupling) in several well‐known hot spots (e.g., the Great Plains, Sahel, and India). Detailed analysis of regional probability distribution functions reveals how the intrinsic relationships of atmosphere variables, land‐atmosphere coupling, and temperature extremes are modified by SP. Regression‐type metrics are also used to examine global land‐atmosphere coupling, with some expected limitations where multiple coupling regimes coexist temporally. Stratifying results by soil moisture percentile proves illuminating in this regard and reveals that SP frequently amplifies land‐atmosphere thermal coupling at the dry end of regional coupling regimes.
Differentiation-state plasticity is a targetable resistance mechanism in basal-like breast cancer
Authors: Risom Tyler , Langer Ellen M. , Chapman Margaret P. , Rantala Juha , Fields Andrew J. , Boniface Christopher , Alvarez Mariano J. , Kendsersky Nicholas D. , Pelz Carl R. , Johnson-Camacho Katherine , Dobrolecki Lacey E. , Chin Koei , Aswani Anil J. , Wang Nicholas J. , Califano Andrea , Lewis Michael T. , Tomlin Claire J. , Spellman Paul T. , Adey Andrew , Gray Joe W. , Sears Rosalie C.
Published: September 2018

Intratumoral heterogeneity in cancers arises from genomic instability and epigenomic plasticity and is associated with resistance to cytotoxic and targeted therapies. We show here that cell-state heterogeneity, defined by differentiation-state marker expression, is high in triple-negative and basal-like breast cancer subtypes, and that drug tolerant persister (DTP) cell populations with altered marker expression emerge during treatment with a wide range of pathway-targeted therapeutic compounds. We show that MEK and PI3K/mTOR inhibitor-driven DTP states arise through distinct cell-state transitions rather than by Darwinian selection of preexisting subpopulations, and that these transitions involve dynamic remodeling of open chromatin architecture. Increased activity of many chromatin modifier enzymes, including BRD4, is observed in DTP cells. Co-treatment with the PI3K/mTOR inhibitor BEZ235 and the BET inhibitor JQ1 prevents changes to the open chromatin architecture, inhibits the acquisition of a DTP state, and results in robust cell death in vitro and xenograft regression in vivo.
An alternative pathway of enteric PEDV dissemination from nasal cavity to intestinal mucosa in swine
Authors: Li Yuchen , Wu Qingxin , Huang Lulu , Yuan Chen , Wang Jialu , Yang Qian
Published: September 2018

Porcine epidemic diarrhea virus (PEDV) has catastrophic impacts on the global pig industry. Although the fecal–oral route is generally accepted, an increased number of reports indicate that airborne transmission may contribute to PEDV outbreak. Here, we show that PEDV could cause typical diarrhea in piglets through a nasal spray. Firstly, PEDV can develop a transient nasal epithelium infection. Subsequently, PEDV-carrying dendritic cells (DCs) allow the virus to be transferred to CD3+ T cells via the virological synapse. Finally, virus-loaded CD3+ T cells reach the intestine through the blood circulation, leading to intestinal infection via cell-to-cell contact. Our study provides evidence for airborne transmission of a gastrointestinal infected coronavirus and illustrates the mechanism of its transport from the entry site to the pathogenic site.
Mechano-regulated metal–organic framework nanofilm for ultrasensitive and anti-jamming strain sensing
Authors: Pan Liang , Liu Gang , Shi Wenxiong , Shang Jie , Leow Wan Ru , Liu Yaqing , Jiang Ying , Li Shuzhou , Chen Xiaodong , Li Run-Wei
Published: September 2018

The development of ultrasensitive, anti-jamming, and durable sensors that can precisely distinguish different human body motions are of great importance for smart health monitoring and diagnosis. Physical implementation of such flexible sensors is still a challenge at the moment. Combining the designs of advanced material showing excellent electrochemical properties with the facilitative structure engineering, high-performance flexible sensors that satisfy both signal detecting and recognition requirements may be made possible. Here we report the first metal–organic framework-based strain sensor with accurate signal detection and noise-screening properties. Upon doping the tricarboxytriphenyl amine-based metal–organic framework nanofilm with iodine, the two-terminal device exhibits ultrahigh sensitivity with a gauge factor exceeding 10,000 in the 2.5% to 3.3% deformation range for over 5000 dynamic operating cycles and out-of-scale noise-screening capability. The high-performance strain sensor can easily differentiate the moderate muscle hyperspasmia from subtle swaying and vigorous sporting activities.
Roquin targets mRNAs in a 3′-UTR-specific manner by different modes of regulation
Authors: Essig Katharina , Kronbeck Nina , Guimaraes Joao C. , Lohs Claudia , Schlundt Andreas , Hoffmann Anne , Behrens Gesine , Brenner Sven , Kowalska Joanna , Lopez-Rodriguez Cristina , Jemielity Jacek , Holtmann Helmut , Reiche Kristin , Hackermüller Jörg , Sattler Michael , Zavolan Mihaela , Heissmeyer Vigo
Published: September 2018

The RNA-binding proteins Roquin-1 and Roquin-2 redundantly control gene expression and cell-fate decisions. Here, we show that Roquin not only interacts with stem–loop structures, but also with a linear sequence element present in about half of its targets. Comprehensive analysis of a minimal response element of the Nfkbid 3′-UTR shows that six stem–loop structures cooperate to exert robust and profound post-transcriptional regulation. Only binding of multiple Roquin proteins to several stem–loops exerts full repression, which redundantly involved deadenylation and decapping, but also translational inhibition. Globally, most Roquin targets are regulated by mRNA decay, whereas a small subset, including the Nfat5 mRNA, with more binding sites in their 3′-UTRs, are also subject to translational inhibition. These findings provide insights into how the robustness and magnitude of Roquin-mediated regulation is encoded in complex cis-elements.
Apoε4 disrupts neurovascular regulation and undermines white matter integrity and cognitive function
Authors: Koizumi Kenzo , Hattori Yorito , Ahn Sung Ji , Buendia Izaskun , Ciacciarelli Antonio , Uekawa Ken , Wang Gang , Hiller Abigail , Zhao Lingzhi , Voss Henning U. , Paul Steven M. , Schaffer Chris , Park Laibaik , Iadecola Costantino
Published: September 2018

The ApoE4 allele is associated with increased risk of small vessel disease, which is a cause of vascular cognitive impairment. Here, we report that mice with targeted replacement (TR) of the ApoE gene with human ApoE4 have reduced neocortical cerebral blood flow compared to ApoE3-TR mice, an effect due to reduced vascular density rather than slowing of microvascular red blood cell flow. Furthermore, homeostatic mechanisms matching local delivery of blood flow to brain activity are impaired in ApoE4-TR mice. In a model of cerebral hypoperfusion, these cerebrovascular alterations exacerbate damage to the white matter of the corpus callosum and worsen cognitive dysfunction. Using 3-photon microscopy we found that the increased white matter damage is linked to an enhanced reduction of microvascular flow resulting in local hypoxia. Such alterations may be responsible for the increased susceptibility to hypoxic-ischemic lesions in the subcortical white matter of individuals carrying the ApoE4 allele.