bluuebunny/crossref_metadata_2025 huggingface dataset:
Matrix‐Assisted Laser Desorption Ionization Mass Spectrometry Imaging of Key Proteins in Corneal Samples from Lattice Dystrophy Patients with TGFBI‐H626R and TGFBI‐R124C Mutations
Authors: Venkatraman Anandalakshmi , Hochart Guillaume , Bonnel David , Stauber Jonathan , Shimmura Shigeto , Rajamani Lakshminaryanan , Pervushin Konstantin , Mehta Jodhbir S.
Published: November 2018

Scope

The purpose of this study is to identify and visualize the spatial distribution of proteins present in amyloid corneal deposits of TGFBI‐CD patients using Mass Spectrometry Imaging (MSI) and compare it with healthy control cornea. Corneal Dystrophies (CD) constitute a group of genetically inherited protein aggregation disorders that affects different layers of the cornea. With accumulated protein deposition, the cornea becomes opaque with decreased visual acuity. CD affecting the stroma and Bowman's membrane, is associated with mutations in transforming growth factor β‐induced (TGFBI) gene.

Methods

MALDI‐Mass Spectrometry Imaging (MSI) is performed on 2 patient corneas and is compared with 1 healthy control cornea using a 7T‐MALDI‐FTICR. Molecular images obtained are overlaid with congo‐red stained sections to visualize the proteins associated with the corneal amyloid aggregates.

Results

MALDI‐MSI provides a relative abundance and two dimensional spatial protein signature of key proteins (TGFBIp, Apolipoprotein A‐I, Apolipoprotein A‐IV, Apolipoprotein E, Kaliocin‐1, Pyruvate Kinase and Ras related protein Rab‐10) in the patient deposits compared to the control. This is the first report of the anatomical localization of key proteins on corneal tissue section from CD patients. This may provide insight in understanding the mechanism of amyloid fibril formation in TGFBI‐corneal dystrophy.
Graphene‐Like Carbon Nanostructures From Combustion Synthesis
Authors: Dąbrowska Agnieszka , Huczko Andrzej
Published: November 2018

Combustion synthesis (CS) (self‐propagating high‐temperature synthesis [SHS]) is a well‐known method of nanomaterials production. Among its advantages one may point out the remarkable number of materials possible to design. It starts from a mixture of a strong reducer and an oxidant and leads to a variety of materials (also metastable). The process is carried out under high pressure (up to 5 MPa) in a reaction chamber and on average after initiation by ohmic heating takes less than a few seconds. Being self‐sustainable it is environmentally friendly and favorable from the energetic point of view. The results of exploratory research on the autothermal synthesis of few‐layered graphite via a CS are presented. It has been shown before that different carbon‐related precursors can be directly converted into novel nanocarbons using strong reducers and the CS approach. In the current work such research is extended toward direct thermic reduction of standard calcium carbonate into few‐layered graphene (FLG). As the oxidizer one may use a variety of minerals: dolomite siderite and limestone. Moreover the following reactant systems have been tested: Si/PTFE/NaCl and Si/CFx in order to obtain graphene flakes and SiC nanowires. To better characterize the product, XRD analysis and Raman spectroscopy might be used. The SHS process mechanism (thermodynamics kinetics of wave propagation) and in situ diagnostics optimization and control are also discussed. Finally, the presented approach is currently under further investigation with preliminary results for the GO/Ti reagent system. It can be additionally extended by a qualitative fractal analysis of the obtained nanomaterials.
Hydrostatic Pressure Dependent Optoelectronic Properties of InGaAsN/GaAs Spherical Quantum Dots for Laser Diode Applications
Authors: Mal Indranil , Jayarubi Joseph , Das Subhasis , Sharma Akant Sagar , Peter Amalorpavam John , Samajdar Dip Prakash
Published: November 2018

The hydrostatic pressure induced band diagram of an InGaAsN/GaAs spherical quantum dot (QD) system is theoretically calculated using an expanded form of standard 8 band k · p Hamiltonian. The band parameters including energy gap, band offsets, and effective masses of electron and hole as a function of hydrostatic pressure are extracted using 10 band k · p model to calculate optical gain, threshold current density, and confined exciton binding energies of the QD system for the possible potential applications in 1.3–1.55 μm laser diodes. The optical gain increases with the increase in hydrostatic pressure up to 30 kbar and eventually decreases for further application of higher pressures. This effect is not usually observed in InGaAsN/GaAs quantum wells owing to the strong dependence of hole and electron effective masses with the hydrostatic pressure. A relative blue shift is observed in the gain spectra due to the increase in hydrostatic pressure or carrier concentration whereas a redshift is observed due to the increase in geometrical dimensions or impurity concentration which helps in estimating the range of operation of InGaAsN/GaAs QD based devices. The obtained binding energies, threshold current densities, and strain within the QDs help in understanding the influence of pressure and dot radius on these parameters.
Facile Synthesis by Peroxide Method and Microwave‐Assisted Hydrothermal Treatment of TiO2 with High Photocatalytic Efficiency for Dye Degradation and Hydrogen Production
Authors: Garcia Ana Paula , Guaglianoni Waleska Campos , Garcia Danielle Rodrigues , Soares Luana Goés , de Oliveira Vaz Maurício , Teixeira Sérgio Ribeiro , Pereira Marcelo Barbalho , Basegio Tania Maria , Clemens Frank Jörg , Alves Annelise Kopp , Rodembusch Fabiano Severo , Bergmann Carlos Pérez
Published: November 2018

Nanostructured titanium dioxide with high photocatalytic efficiency was synthesised by the oxidant peroxide method and microwave‐assisted hydrothermal treatment without calcination or doping. The influence of pH during hydrothermal treatment was investigated on the morphology, crystallinity, phase composition, specific surface area, photoluminescence properties, and photocatalytic behaviour. The pH of the medium had no significant effect on the nanostructured titanium dioxide morphologies but at higher pH, the powders presented lower surface area and higher particle size. A slight decrease in the photoluminescence intensity of the sample prepared at low pH was related to surface protonation. This material also exhibited higher photocatalytic performance in degrading methyl orange solutions than those obtained at a higher pH or commercial TiO2. Aditionally, the hydrogen production rate increased with the solution pH following heat treatment, with optimized results in deionized water. Finally, the powders did not require either heat treatment or doping with another metal to achieve more activity than the commercially available oxide.
In Situ Constructing MoS2‐C Nanospheres as Advanced Anode for Sodium‐Ion Battery
Authors: Liu Lihuai , Shi Rongjia , Li Yanjuan , Wu Yufen , Ye Kun , Yan Xiao , Shi Yanhui , Cao Changsheng
Published: November 2018

Striving for achievements of anode materials with excellent rate capability and long cycle life is a key to the commercial progress of sodium‐ion batteries. In the present work, we report a spherical MoS2‐C nanocomposite as anode for sodium‐ion batteries (SIBs) with high‐performance. The active materials were prepared via an in situ solvothermal reaction, in which carbon and MoS2 were simultaneously formed in one pot using toluene, acetone and ethanol as solvents. SEM results show that the controlled morphology has relative to the solvents, and the thermal gravimetric (TG) and Raman spectrum results indicated that the carbon was in situ formed. The MoS2‐C nano‐spheres were applied for sodium ion batteries. The results illustrate that MoS2‐C harvested from ethanol demonstrates the best electrochemical performances with long cycling stability (430 mA h g−1 after 100th cycles at 0.2 A g−1) and high rate capability (248 mA h g−1 at 5 A g−1). The superior properties of MoS2‐C nanocoposite benefits from several merits: (1) nanoscale size can short path of Na+ diffusion, enlarge electrode/electrolyte contact area, (2) sphere structure possesses good stress–strain relief during Na+ insertion/extraction reactions and consequently decreases huge volume variation, (3) the carbon in situ formed between MoS2 particles can improve the intrinsically poor electronic conductivity leading to higher rate capability. The novel MoS2‐C architectures provide a new avenue to fabricate carbon coupled with sulfides materials with excellent performances.
Methyl Red as Organocatalyst for Arylation of Unactivated Benzene Derivatives with Aryl Halides
Authors: Ghonchepour Ehsan , Islami Mohammad Reza , Tikdari Ahmad Momeni
Published: November 2018

Transition‐metal‐free arylation of benzene derivatives with aryl halides using KOtBu and methyl red as an organocatalyst is described in this letter. This facile one‐pot reaction is reported as an unprecedented C−H functionalization protocol for the synthesis of biaryls. Several organic acids we tested and among them, methyl red was found to be the best catalyst for this cross‐coupling. This method was designed based on the principles of green chemistry due to avoiding the use of stoichiometric of reagents, any expensive and toxic transition‐metal catalysts. We believe this procedure will become an acceptable method and could be very well compared with known protocols for biphenyl cross coupling.
A Simple Colorimetric Method for Naked‐Eye Detection of Circulating Cell‐Free DNA Using Unlabelled Gold Nanoparticles
Authors: Khanna Shweta , Padhan Prasanta , Das Sourav , Jaiswal Kumar Sagar , Tripathy Archana , Smita Shuchi , Tripathy Suraj K. , Raghav Sunil Kumar , Gupta Bhawna
Published: November 2018

Gaining interests and expediency of precision medicine for various diseases has led to the search for non invasive techniques like liquid biopsies involving study of circulating cell free DNA (cfDNA) for diagnostic as well as prognostic applications. Present study reports that cfDNA in plasma of patients with Rheumatoid Arthritis are fragmented, modified and hence remain undetected using qPCR, the commonly used analytical assay. They are immunogenic to peripheral blood cells and stimulate them to secrete TNF‐α, a pro‐inflammatory cytokine making it imperative to detect cfDNA in patients for an effective therapeutic intervention. Hereby a non‐invasive colorimetric assay for naked eye discernment of cfDNA using gold nanoparticles is proposed which is potent in detecting long and short cfDNA fragments from small amount of blood, is inexpensive, label free, easy to perform and allows visual detection. This can be further explored to assess its diagnostic and prognostics implications in various human disorders.
Preferred C2−H Activation of Quinoline N‐Oxides Catalyzed by Palladium Acetate: DFT Study on the Plausible Mechanism and Regioselectivity
Authors: Zhang Lei , Jiang Bo , Zhou Jianguo , Yu Lu , Chen Yu
Published: November 2018

A density functional theory study on the multi‐path and multi‐step C−H activation of quinoline N‐oxides catalyzed by the dimeric complex Pd2(OAc)4 has been carried out to fully address the strong preference for C2−H activation observed experimentally. The plausible C−H activation mechanism was identified as the undirected mechanism rather than the coordination‐directed mechanism, because the former has lower free‐energy barriers than the latter. The kinetic and thermodynamic parameters of different C−H activation reactions have been calculated and compared. The preference for C2−H activation over C8−H activation should be a result of the kinetic discrimination, while that over the remaining C−H activation processes could be attributed to the thermodynamic spontaneity.
Water‐Assisted Emission Enhancement of 2‐Hydroxynaphthaldoxime and Related Compounds
Authors: Tarai Arup , Baruah Jubaraj B.
Published: November 2018

The combined contributions from the excited‐state intramolecular proton‐transfer and aggregation‐induced emission in the photoluminescence of compounds namely 2‐hydroxynaphthaldoxime, 2‐methoxynaphthaldoxime, 2‐hydroxynaphthaldehyde and 1‐[(methylimino)methyl]naphthalen‐2‐ol were established. For such a purpose the changes in the fluorescence emission of these compounds in different solvents upon addition of water and from the fluorescence emission life‐time decay profiles were studied. 1H‐NMR titration of the 2‐hydroxynaphthaldoxime with D2O had provided clear evidence on the role of water molecules to disrupt the C−H⋅⋅⋅O interactions in assembly of 2‐hydroxynaphthaldoxime to orient the aromatic naphthalene rings differently to enhance the fluorescence emissions. Dynamic light scattering studies and scanning electron micrographs had showed that there were differences between the types of aggregation present in solid state and in solution. In solution the average size of the aggregates of 2‐hydroxynaphthaldoxime were increased upon addition of water. 2‐Hydroxynaphthaldoxime formed well defined cocrystal with tetrabutylammonium chloride but the tetrabutylammonium hydroxide formed salt of 2‐hydroxynaphthaldoxime by deprotonating hydroxy‐group. Accordingly the fluorescence emission changes of 2‐hydroxynaphthaldoxime caused by tetrabutylammonium hydroxide was different from the emission showed by the cocrystal with tetrabutylammonium chloride.
Sphere‐to‐Multipod Transmorphic Change of Nanoconfined Pt Electrocatalyst during Oxygen Reduction Reaction
Authors: Yang Juchan , Kang Dongwoo , Jeon Yuju , Lee Jong Hoon , Jeong Hu Young , Shin Hyeon Suk , Song Hyun‐Kon
Published: November 2018

An oxygen reduction reaction (ORR) catalyst/support system is designed to have Pt nanoparticles nanoconfined in a nanodimensionally limited space. Holey crumpled reduced graphene oxide plates (hCR‐rGO) are used as a carbon support for Pt loading. As expected from interparticular Pt‐to‐Pt distance of Pt‐loaded hCR‐rGO longer than that of Pt/C (Pt‐loaded carbon black as a practical Pt catalyst), the durability of ORR electroactivity along cycles is improved by replacing the widely used carbon black with hCR‐rGO. Unexpected morphological changes of Pt are electrochemically induced during repeated ORR processes. Spherical multifaceted Pt particles are evolved to {110}‐dominant dendritic multipods. Nanoconfinement of a limited number of Pt within a nanodimensionally limited space is responsible for the morphological changes. The improved durability observed from Pt‐loaded hCR‐rGO originates from 1) dendritic pod structure of Pt exposing more active sites to reactants and 2) highly ORR‐active Pt {110} planes dominant on the surface.
One‐Step Synthesis of NiMn‐Layered Double Hydroxide Nanosheets Efficient for Water Oxidation
Authors: Li Ruiqi , Liu Yuqian , Li Haobo , Zhang Man , Lu Yiran , Zhang Lin , Xiao Jianping , Boehm Frank , Yan Kai
Published: November 2018

Layered double hydroxides (LDHs) are noble metal–free 2D materials promising for water oxidation. One‐step synthesis of ultrathin NiMn‐LDHs nanosheets is successfully achieved at room temperature avoiding the multiple tedious steps (e.g., hydrothermal treatment, exfoliation). The as‐prepared NiMn‐LDHs (1.3 nm thickness) exhibit the twofold enhancement of the activity and a reduction of overpotential by 80 mV at 10 mA cm−2 in comparison with the traditional NiMn‐LDHs in 0.1 m NaOH, which is superior to the previously reported LDH‐derived electrocatalysts. The combination of theoretical and experimental results manifest that the largely enhanced electrocatalytic water oxidation activity of NiMn‐LDHs nanosheets is associated with the highly exposed active sites with a nearly optimal intermediates (*OH and *O) adsorption energy.
Surface and Interface Chemistry in Colloidal Quantum Dots for Solar Applications Studied by X‐Ray Photoelectron Spectroscopy
Authors: Clark Pip C. J. , Flavell Wendy R.
Published: November 2018

Control of the surface and interface chemistry of colloidal quantum dots (CQDs) is critical to achieving a product with good air stability and high performing optoelectronic devices. Through various surface passivation treatments, vast improvements have been made in fields such as CQD photovoltaics; however devices have not currently reached commercial standards. We show how X‐ray photoelectron spectroscopy (XPS) can provide a better understanding of exactly how surface treatments act on CQD surfaces, and the effect of surface composition on air stability and device performance.. We illustrate this with PbS‐based CQDs, using XPS to measure oxidation processes, and to quantify the composition of the topmost surface layer after different surface treatments. We also demonstrate the use of synchrotron radiation‐excited depth‐profiling XPS, a powerful technique for determining the surface composition, chemistry and structure of CQDs. This review describes our recent progress in characterization of CQD surfaces using SR‐excited depth profiling XPS and other photoemission techniques.
Incommensurability and Paradigm Crossing: Folding the EGs Back into the Omelet or Blood in the Water?
Authors: Shaw Michael , Nowicki Andrew
Published: November 2018

The Empirical Generalists (EGs) suggest that the accepted focus on segmentation and loyalty in Marketing Management is irrelevant and that the Dirichlet equation and Double Jeopardy provide the only useful theory of consumer behavior. Meanwhile the Segmentationalists adhere to a Marketing Management model and blithely ignore their claims. This discussion examines the extremes of a continuum which extends from the breadth of Kotler (1967) to the reductive analysis of Sharp (2010) . Lowe et al., (2004) have provided an easily understood set of categories that describes these paradigmatic differences. This is applied along with an integrative framework adapted from Rossiter, (2012) which suggests remedial linkages. However recent work by the Empirical Generalists suggests that this is flogging a dead horse. The response from Marketing Management adherents has been a refusal to engage and a denial of oxygen to the debate. The implications for marketing strategy are considerable since the continued utility of the key technique of segmentation is under challenge. Will it survive as a valid technique for addressing the market or will it be reduced to a mere description of customer type? Is it a harmless symbolic activity or an organizational hallucination that blocks progress?
Turbulent dynamics of sinusoidal oscillatory flow over a wavy bottom
Authors: Önder Asim , Yuan Jing
Published: November 2018

A direct numerical simulation study is conducted to investigate sinusoidal oscillatory flow over a two-dimensional wavy wall. The height and wavelength of the bottom profile, and the period and amplitude of the free-stream oscillation, are selected to mimic a wave-driven boundary layer over vortex ripples on a sandy seabed. Two cases with different Reynolds numbers$(Re)$are considered, and the higher-$Re$case achieves a fully developed turbulent state with a wide separation between the energy-containing and dissipative scales. The oscillatory flow is characterized by coherent columnar vortices, which are the main transport agents of turbulent kinetic energy and enstrophy. Two classes of coherent vortices are observed: (i) a primary vortex formed at the lee side of the ripple by flow separation at the crest; (ii) a secondary vortex formed beneath the primary vortex by vortex-induced separation. When the free-stream velocity weakens, these vortices form a counter-rotating vortex dipole and eject themselves over the crest with their mutual induction. Turbulence production peaks twice in a half-cycle; during the formation of the primary vortex and during the ejection of the vortex dipole. The intensity of the former peak remains low in the lower-$Re$case, as the vortex dipole follows a higher altitude trajectory limiting its interactions with the bottom, and leaving minimal residual turbulence around the ripples for the subsequent half-cycle. Flow snapshots and spectral analysis reveal two dominant three-dimensional features: (i) an energetic vortex mode with a preferred spanwise wavelength close to the ripple wavelength; (ii) streamwise vortical structures in near-wall regions with a relatively shorter spanwise spacing influenced by viscous effects. The vortex mode becomes strong when the cores of the vortices are strained to an elliptical form while moving towards the crest. Following the detachment of the vortices from the ripple, the vortex mode in the higher-$Re$case breaks down the spanwise coherence of the columnar vortices and decomposes them into intermittent patches of turbulent vortex clusters. The distribution of wall shear stress over the ripple is also analysed in detail. The peak values are observed near the ripple crest around the ejection of the vortex dipole and the maximum free-stream velocity. In the former, both the vortex mode and streamwise vortices have strong footprints on the wall, yielding a bimodal wall-shear-stress spectrum with two distinctive peaks. In the second high-stress regime, decaying coherent vortices impose strong inhomogeneity on the wall shear stress as their wall-attached parts sweep the ripples. These spanwise variations in the wall shear provide insights into the instability of two-dimensional sand ripples.
Subgrid modelling for two-dimensional turbulence using neural networks
Authors: Maulik R. , San O. , Rasheed A. , Vedula P.
Published: November 2018

In this investigation, a data-driven turbulence closure framework is introduced and deployed for the subgrid modelling of Kraichnan turbulence. The novelty of the proposed method lies in the fact that snapshots from high-fidelity numerical data are used to inform artificial neural networks for predicting the turbulence source term through localized grid-resolved information. In particular, our proposed methodology successfully establishes a map between inputs given by stencils of the vorticity and the streamfunction along with information from two well-known eddy-viscosity kernels. Through this we predict the subgrid vorticity forcing in a temporally and spatially dynamic fashion. Our study is botha priorianda posterioriin nature. In the former, we present an extensive hyper-parameter optimization analysis in addition to learning quantification through probability-density-function-based validation of subgrid predictions. In the latter, we analyse the performance of our framework for flow evolution in a classical decaying two-dimensional turbulence test case in the presence of errors related to temporal and spatial discretization. Statistical assessments in the form of angle-averaged kinetic energy spectra demonstrate the promise of the proposed methodology for subgrid quantity inference. In addition, it is also observed that some measure ofa posteriorierror must be considered during optimal model selection for greater accuracy. The results in this article thus represent a promising development in the formalization of a framework for generation of heuristic-free turbulence closures from data.
Influence of pressure-dependent surface viscosity on dynamics of surfactant-laden drops in shear flow
Authors: Luo Zheng Yuan , Shang Xing Long , Bai Bo Feng
Published: November 2018

We study numerically the dynamics of an insoluble surfactant-laden droplet in a simple shear flow taking surface viscosity into account. The rheology of drop surface is modelled via a Boussinesq–Scriven constitutive law with both surface tension and surface viscosity depending strongly on the surface concentration of the surfactant. Our results show that the surface viscosity exhibits non-trivial effects on the surfactant transport on the deforming drop surface. Specifically, both dilatational and shear surface viscosity tend to eliminate the non-uniformity of surfactant concentration over the drop surface. However, their underlying mechanisms are entirely different; that is, the shear surface viscosity inhibits local convection due to its suppression on drop surface motion, while the dilatational surface viscosity inhibits local dilution due to its suppression on local surface dilatation. By comparing with previous studies of droplets with surface viscosity but with no surfactant transport, we find that the coupling between surface viscosity and surfactant transport induces non-negligible deviations in the dynamics of the whole droplet. More particularly, we demonstrate that the dependence of surface viscosity on local surfactant concentration has remarkable influences on the drop deformation. Besides, we analyse the full three-dimensional shape of surfactant-laden droplets in simple shear flow and observe that the drop shape can be approximated as an ellipsoid. More importantly, this ellipsoidal shape can be described by a standard ellipsoidal equation with only one unknown owing to the finding of an unexpected relationship among the drop’s three principal axes. Moreover, this relationship remains the same for both clean and surfactant-laden droplets with or without surface viscosity.
Jet formation in salt-finger convection: a modified Rayleigh–Bénard problem
Authors: Xie Jin-Han , Julien Keith , Knobloch Edgar
Published: November 2018

Large-scale coherent structures such as jets in Rayleigh–Bénard convection and related systems are receiving increasing attention. This paper studies, both numerically and theoretically, the process of jet formation in two-dimensional salt-finger convection. The approach utilizes an asymptotically derived system of equations referred to as the modified Rayleigh–Bénard convection (MRBC) model, valid in the geophysically and astrophysically relevant limit in which the solute diffuses much more slowly than heat. In these equations, convection is driven by a destabilizing salinity gradient while the effects of the stabilizing temperature gradient manifest themselves as an additional anisotropic dissipation acting on large scales. The MRBC system is specified by two external parameters: the Schmidt number $\mathit{Sc}$ (ratio of viscosity to solutal diffusivity) and the Rayleigh ratio $\mathit{Ra}$ (ratio between the Rayleigh numbers of the destabilizing solutal stratification and the stabilizing thermal stratification). Two distinct $\mathit{Ra}$ regimes are explored for fixed $\mathit{Sc}=1$. In all cases studied the system develops a horizontal jet structure that is maintained self-consistently by turbulent fluctuations, but coarsens over time. For intermediate Rayleigh ratios (e.g. $\mathit{Ra}=6$), the MRBC model captures the relaxation oscillations superposed on the jet structure observed at similar parameter values in direct numerical simulations of the primitive equations. For smaller Rayleigh ratios (e.g. $\mathit{Ra}=2$), a regime for which direct numerical simulation of the primitive equations is difficult because of the presence of fast gravity waves, the MRBC model reveals the existence of statistically steady jets whose properties are studied in detail. Three hierarchical models, the MRBC and further reductions in the form of quasilinear and single-mode approximations, are used to confirm that jets form and are sustained as a result of the interaction between fluctuations (salt fingers) and large-scale horizontally averaged horizontal flows (jets). Even though the small-scale structures exhibited by the three models exhibit clear differences, all three produce the same power-law spectrum of the mean fields at large vertical scales: in all, the spectrum of the mean streamfunction scales as $m^{-3}$ and the mean salinity field scales as $m^{-1}$, with $m$ the vertical wavenumber. A theoretical explanation of these observations based on the dominant balances in the mean and fluctuation equations is provided. As a consequence, the jets have a zigzag profile, a conclusion that is consistent with numerical simulations. Based on numerical observations, a three-component phenomenological model consisting of a linearly growing mode, a linearly damped mode and a mean mode is proposed to explain the observed transition from statistically steady jet structure to jets with superposed oscillations that takes place with increasing Rayleigh ratio.
Markovian inhomogeneous closures for Rossby waves and turbulence over topography
Authors: Frederiksen Jorgen S. , O’Kane Terence J.
Published: November 2018

Manifestly Markovian closures for the interaction of two-dimensional inhomogeneous turbulent flows with Rossby waves and topography are formulated and compared with large ensembles of direct numerical simulations (DNS) on a generalized$\unicode[STIX]{x1D6FD}$-plane. Three versions of the Markovian inhomogeneous closure (MIC) are established from the quasi-diagonal direct interaction approximation (QDIA) theory by modifying the response function to a Markovian form and employing respectively the current-time (quasi-stationary) fluctuation dissipation theorem (FDT), the prior-time (non-stationary) FDT and the correlation FDT. Markov equations for the triad relaxation functions are derived that carry similar information to the time-history integrals of the non-Markovian QDIA closure but become relatively more efficient for long integrations. Far from equilibrium processes are studied, where the impact of a westerly mean flow on a conical mountain generates large-amplitude Rossby waves in a turbulent environment, over a period of 10 days. Excellent agreement between the evolved mean streamfunction and mean and transient kinetic energy spectra are found for the three versions of the MIC and two variants of the non-Markovian QDIA compared with an ensemble of 1800 DNS. In all cases mean Rossby wavetrain pattern correlations between the closures and the DNS ensemble are greater than 0.9998.
BUILDINGS, LANDSCAPES AND REGIMES OF MATERIALITY
Authors: Whyte William
Published: November 2018

Beginning with a surprisingly exuberant response to the landscape recorded by a distinguished scholar, this paper explores the agency of things and places though time. It argues that the recent ‘material turn’ is part of a broader re-enchantment of the world: a re-enchantment that has parallels with a similar process at the turn of the nineteenth century. Tracing this history suggests that within the space of a single generation the material world can be enchanted or disenchanted, with things and places imbued with – or stripped of –agency. In other words, different periods possess what we might call different regimes of materiality. Any approach which assumes the existence of material agency throughout history, or which imports our assumptions into a period which did not share them, will necessarily fail. Before we look at the material world, therefore, we need to examine how the material world was looked at, how it was conceptualised and how it was experienced. We need to apprehend its regime of materiality.
Subjective Perceptions of the Teaching–Research Nexus and Occupational Stress at Universities
Authors: Daumiller Martin , Dresel Markus
Published: November 2018

Abstract. The duality of research and teaching is fundamental for university systems; however, it is often experienced as stressful. A study with 819 university scholars indicated the importance of subjective perceptions of the teaching–research nexus. Such views could be differentiated in perceived integration (e. g., research is part of teaching) and perceived synergy (e. g., research enriches teaching). Structural equation modeling showed that only perceived synergy was associated with reduced occupational stress.
The Utility of Personnel Selection Decisions
Authors: Ock Jisoo , Oswald Frederick L.
Published: November 2018

Abstract. Compensatory selection is generally more reliable than multiple-hurdle selection. Yet, practitioners may lean toward multiple-hurdle models, because administering an entire predictor battery to every applicant can be time-consuming, labor-intensive, and costly. Using Monte Carlo simulation, we considered some specific cases to illustrate, in terms of selection utility and the cost-reliability tradeoff between compensatory and multiple-hurdle selection models. Results showed that compensatory model selection produced a higher level of expected criterion performance in the selected applicant subgroup, and a higher overall selection utility in most conditions. The simulation provides researchers and practitioners with a practical illustration of the tradeoff between reliable (compensatory) versus cost-efficient (multiple-hurdle) selection models – one that can inspire the exploration of other scenarios and tradeoffs.
Recruitment Process Outsourcing and Recruiter and Hiring Firm Characteristics
Authors: Landay Karen , DeArmond Sarah
Published: November 2018

Abstract. Recruitment process outsourcing (RPO) is rapidly expanding across the globe. However, understanding of its effects on job applicants remains limited. Using signaling theory, we examined the effects of recruiter characteristics, hiring firm reputation, and RPO on organization attraction in two experimental studies. Results showed significant main effects of recruiter competence, recruiter personableness, and hiring firm reputation on organization attraction. We also found significant interactions between both recruiter characteristics and RPO. This indicates that, contrary to prior research, RPO is more accurately conceptualized as a boundary condition that indicates to applicants when recruiter characteristics are relevant signals.
Estrogen receptor β upregulated by lncRNA-H19 to promote cancer stem-like properties in papillary thyroid carcinoma
Authors: Li Mei , Chai Hui-Fang , Peng Fei , Meng Yu-Ting , Zhang Li-Zhi , Zhang Lin , Zou Hong , Liang Qi-Lan , Li Man-Man , Mao Kai-Ge , Sun Dong-Xu , Tong Meng-Ying , Deng Zi-Qian , Hou Zhi-Jie , Zhao Yi , Li Jia , Wang Xiao-Chao , Lv Sha-Sha , Zhang Qing-Qing , Yu Xiao , Lam Eric W.-F. , Liu Quentin , Cui Xiao-Nan , Xu Jie
Published: November 2018

Estrogen receptor β (ERβ) plays critical roles in thyroid cancer progression. However, its role in thyroid cancer stem cell maintenance remains elusive. Here, we report that ERβ is overexpressed in papillary thyroid cancer stem cells (PTCSCs), whereas ablation of ERβ decreases stemness-related factors expression, diminishes ALDH+ cell populations, and suppresses sphere formation ability and tumor growth. Screening estrogen-responsive lncRNAs in PTC spheroid cells, we find that lncRNA-H19 is highly expressed in PTCSCs and PTC tissue specimens, which is correlated with poor overall survival. Mechanistically, estradiol (E2) significantly promotes H19 transcription via ERβ and elevates H19 expression. Silencing of H19 inhibits E2-induced sphere formation ability. Furthermore, H19 acting as a competitive endogenous RNA sequesters miRNA-3126-5p to reciprocally release ERβ expression. ERβ depletion reverses H19-induced stem-like properties upon E2 treatment. Appropriately, ERβ is upregulated in PTC tissue specimens. Notably, aspirin attenuates E2-induced cancer stem-like traits through decreasing both H19 and ERβ expression. Collectively, our findings reveal that ERβ-H19 positive feedback loop has a compelling role in PTCSC maintenance under E2 treatment and provides a potential therapeutic targeting strategy for PTC.
Overexpression of the vascular brassinosteroid receptor BRL3 confers drought resistance without penalizing plant growth
Authors: Fàbregas Norma , Lozano-Elena Fidel , Blasco-Escámez David , Tohge Takayuki , Martínez-Andújar Cristina , Albacete Alfonso , Osorio Sonia , Bustamante Mariana , Riechmann José Luis , Nomura Takahito , Yokota Takao , Conesa Ana , Alfocea Francisco Pérez , Fernie Alisdair R. , Caño-Delgado Ana I.
Published: November 2018

Drought represents a major threat to food security. Mechanistic data describing plant responses to drought have been studied extensively and genes conferring drought resistance have been introduced into crop plants. However, plants with enhanced drought resistance usually display lower growth, highlighting the need for strategies to uncouple drought resistance from growth. Here, we show that overexpression of BRL3, a vascular-enriched member of the brassinosteroid receptor family, can confer drought stress tolerance in Arabidopsis. Whereas loss-of-function mutations in the ubiquitously expressed BRI1 receptor leads to drought resistance at the expense of growth, overexpression of BRL3 receptor confers drought tolerance without penalizing overall growth. Systematic analyses reveal that upon drought stress, increased BRL3 triggers the accumulation of osmoprotectant metabolites including proline and sugars. Transcriptomic analysis suggests that this results from differential expression of genes in the vascular tissues. Altogether, this data suggests that manipulating BRL3 expression could be used to engineer drought tolerant crops.
A rice Serine/Threonine receptor-like kinase regulates arbuscular mycorrhizal symbiosis at the peri-arbuscular membrane
Authors: Roth Ronelle , Chiapello Marco , Montero Héctor , Gehrig Peter , Grossmann Jonas , O’Holleran Kevin , Hartken Denise , Walters Fergus , Yang Shu-Yi , Hillmer Stefan , Schumacher Karin , Bowden Sarah , Craze Melanie , Wallington Emma J. , Miyao Akio , Sawers Ruairidh , Martinoia Enrico , Paszkowski Uta
Published: November 2018

In terrestrial ecosystems most plant species live in mutualistic symbioses with nutrient-delivering arbuscular mycorrhizal (AM) fungi. Establishment of AM symbioses includes transient, intracellular formation of fungal feeding structures, the arbuscules. A plant-derived peri-arbuscular membrane (PAM) surrounds the arbuscules, mediating reciprocal nutrient exchange. Signaling at the PAM must be well coordinated to achieve this dynamic cellular intimacy. Here, we identify the PAM-specific Arbuscular Receptor-like Kinase 1 (ARK1) from maize and rice to condition sustained AM symbiosis. Mutation of rice ARK1 causes a significant reduction in vesicles, the fungal storage structures, and a concomitant reduction in overall root colonization by the AM fungus Rhizophagus irregularis. Arbuscules, although less frequent in the ark1 mutant, are morphologically normal. Co-cultivation with wild-type plants restores vesicle and spore formation, suggesting ARK1 function is required for the completion of the fungal life-cycle, thereby defining a functional stage, post arbuscule development.
An interpretable approach for social network formation among heterogeneous agents
Authors: Yuan Yuan , Alabdulkareem Ahmad , Pentland Alex ‘Sandy’
Published: November 2018

Understanding the mechanisms of network formation is central in social network analysis. Network formation has been studied in many research fields with their different focuses; for example, network embedding algorithms in machine learning literature consider broad heterogeneity among agents while the social sciences emphasize the interpretability of link formation mechanisms. Here we propose a social network formation model that integrates methods in multiple disciplines and retain both heterogeneity and interpretability. We represent each agent by an “endowment vector” that encapsulates their features and use game-theoretical methods to model the utility of link formation. After applying machine learning methods, we further analyze our model by examining micro- and macro- level properties of social networks as most agent-based models do. Our work contributes to the literature on network formation by combining the methods in game theory, agent-based modeling, machine learning, and computational sociology.
HLA-B57 micropolymorphism defines the sequence and conformational breadth of the immunopeptidome
Authors: Illing Patricia T. , Pymm Phillip , Croft Nathan P. , Hilton Hugo G. , Jojic Vladimir , Han Alex S. , Mendoza Juan L. , Mifsud Nicole A. , Dudek Nadine L. , McCluskey James , Parham Peter , Rossjohn Jamie , Vivian Julian P. , Purcell Anthony W.
Published: November 2018

Immunophenotypic differences between closely related human leukocyte antigen (HLA) alleles have been associated with divergent clinical outcomes in infection, autoimmunity, transplantation and drug hypersensitivity. Here we explore the impact of micropolymorphism on peptide antigen presentation by three closely related HLA molecules, HLA-B*57:01, HLA-B*57:03 and HLA-B*58:01, that are differentially associated with the HIV elite controller phenotype and adverse drug reactions. For each allotype, we mine HLA ligand data sets derived from the same parental cell proteome to define qualitative differences in peptide presentation using classical peptide binding motifs and an unbiased statistical approach. The peptide repertoires show marked qualitative overlap, with 982 peptides presented by all allomorphs. However, differences in peptide abundance, HLA-peptide stability, and HLA-bound conformation demonstrate that HLA micropolymorphism impacts more than simply the range of peptide ligands. These differences provide grounds for distinct immune reactivity and insights into the capacity of micropolymorphism to diversify immune outcomes.
A structural mechanism for directing corepressor-selective inverse agonism of PPARγ
Authors: Brust Richard , Shang Jinsai , Fuhrmann Jakob , Mosure Sarah A. , Bass Jared , Cano Andrew , Heidari Zahra , Chrisman Ian M. , Nemetchek Michelle D. , Blayo Anne-Laure , Griffin Patrick R. , Kamenecka Theodore M. , Hughes Travis S. , Kojetin Douglas J.
Published: November 2018

Small chemical modifications can have significant effects on ligand efficacy and receptor activity, but the underlying structural mechanisms can be difficult to predict from static crystal structures alone. Here we show how a simple phenyl-to-pyridyl substitution between two common covalent orthosteric ligands targeting peroxisome proliferator-activated receptor (PPAR) gamma converts a transcriptionally neutral antagonist (GW9662) into a repressive inverse agonist (T0070907) relative to basal cellular activity. X-ray crystallography, molecular dynamics simulations, and mutagenesis coupled to activity assays reveal a water-mediated hydrogen bond network linking the T0070907 pyridyl group to Arg288 that is essential for corepressor-selective inverse agonism. NMR spectroscopy reveals that PPARγ exchanges between two long-lived conformations when bound to T0070907 but not GW9662, including a conformation that prepopulates a corepressor-bound state, priming PPARγ for high affinity corepressor binding. Our findings demonstrate that ligand engagement of Arg288 may provide routes for developing corepressor-selective repressive PPARγ ligands.
Syncytial germline architecture is actively maintained by contraction of an internal actomyosin corset
Authors: Priti Agarwal , Ong Hui Ting , Toyama Yusuke , Padmanabhan Anup , Dasgupta Sabyasachi , Krajnc Matej , Zaidel-Bar Ronen
Published: November 2018

Syncytial architecture is an evolutionarily-conserved feature of the germline of many species and plays a crucial role in their fertility. However, the mechanism supporting syncytial organization is largely unknown. Here, we identify a corset-like actomyosin structure within the syncytial germline of Caenorhabditis elegans, surrounding the common rachis. Using laser microsurgery, we demonstrate that actomyosin contractility within this structure generates tension both in the plane of the rachis surface and perpendicular to it, opposing membrane tension. Genetic and pharmacological perturbations, as well as mathematical modeling, reveal a balance of forces within the gonad and show how changing the tension within the actomyosin corset impinges on syncytial germline structure, leading, in extreme cases, to sterility. Thus, our work highlights a unique tissue-level cytoskeletal structure, and explains the critical role of actomyosin contractility in the preservation of a functional germline.
Proteostasis by STUB1/HSP70 complex controls sensitivity to androgen receptor targeted therapy in advanced prostate cancer
Authors: Liu Chengfei , Lou Wei , Yang Joy C. , Liu Liangren , Armstrong Cameron M. , Lombard Alan P. , Zhao Ruining , Noel Onika D. V. , Tepper Clifford G. , Chen Hong-Wu , Dall’Era Marc , Evans Christopher P. , Gao Allen C.
Published: November 2018

Protein homeostasis (proteostasis) is a potential mechanism that contributes to cancer cell survival and drug resistance. Constitutively active androgen receptor (AR) variants confer anti-androgen resistance in advanced prostate cancer. However, the role of proteostasis involved in next generation anti-androgen resistance and the mechanisms of AR variant regulation are poorly defined. Here we show that the ubiquitin-proteasome-system (UPS) is suppressed in enzalutamide/abiraterone resistant prostate cancer. AR/AR-V7 proteostasis requires the interaction of E3 ubiquitin ligase STUB1 and HSP70 complex. STUB1 disassociates AR/AR-V7 from HSP70, leading to AR/AR-V7 ubiquitination and degradation. Inhibition of HSP70 significantly inhibits prostate tumor growth and improves enzalutamide/abiraterone treatments through AR/AR-V7 suppression. Clinically, HSP70 expression is upregulated and correlated with AR/AR-V7 levels in high Gleason score prostate tumors. Our results reveal a novel mechanism of anti-androgen resistance via UPS alteration which could be targeted through inhibition of HSP70 to reduce AR-V7 expression and overcome resistance to AR-targeted therapies.
Real-time coherent diffraction inversion using deep generative networks
Authors: Cherukara Mathew J. , Nashed Youssef S. G. , Harder Ross J.
Published: November 2018

Phase retrieval, or the process of recovering phase information in reciprocal space to reconstruct images from measured intensity alone, is the underlying basis to a variety of imaging applications including coherent diffraction imaging (CDI). Typical phase retrieval algorithms are iterative in nature, and hence, are time-consuming and computationally expensive, making real-time imaging a challenge. Furthermore, iterative phase retrieval algorithms struggle to converge to the correct solution especially in the presence of strong phase structures. In this work, we demonstrate the training and testing of CDI NN, a pair of deep deconvolutional networks trained to predict structure and phase in real space of a 2D object from its corresponding far-field diffraction intensities alone. Once trained, CDI NN can invert a diffraction pattern to an image within a few milliseconds of compute time on a standard desktop machine, opening the door to real-time imaging.
Spontaneous innovation of hook-bending and unbending in orangutans (Pongo abelii)
Authors: Laumer I. B. , Call J. , Bugnyar T. , Auersperg A. M. I.
Published: November 2018

Betty the crow astonished the scientific world as she spontaneously crafted hook-tools from straight wire in order to lift a basket out of vertical tubes. Recently it was suggested that this species’ solution was strongly influenced by predispositions from behavioural routines from habitual hook-tool manufacture. Nevertheless, the task became a paradigm to investigate tool innovation. Considering that young humans had surprising difficulties with the task, it was yet unclear whether the innovation of a hooked tool would be feasible to primates that lacked habitual hook making. We thus tested five captive orangutans in a hook bending and unbending task. Orangutans are habitually tool-using primates that have been reported to use but not craft hooked tools for locomotion in the wild. Two orangutans spontaneously innovated hook tools and four unbent the wire from their first trial on. Pre-experience with ready-made hooks had some effect but did not lead to continuous success. Further subjects improved the hook-design feature when the task required the subjects to bent the hook at a steeper angle. Our results indicate that the ability to represent and manufacture tools according to a current need does not require stereotyped behavioural routines, but can indeed arise innovatively. Furthermore, the present study shows that the capacity for hook tool innovation is not limited to large brained birds within non-human animals.