bluuebunny/crossref_metadata_2025 huggingface dataset:
The staging mechanism of AlCl4 intercalation in a graphite electrode for an aluminium-ion battery
Authors: Bhauriyal Preeti , Mahata Arup , Pathak Biswarup
Published: February 2017

Identifying a suitable electrode material with desirable electrochemical properties remains a primary challenge for rechargeable Al-ion batteries.
The dynamics of solvation dictates the conformation of polyethylene oxide in aqueous, isobutyric acid and binary solutions
Authors: Dahal Udaya R. , Dormidontova Elena E.
Published: February 2017

The dynamics of solvation dictates the conformation of polyethylene oxide in water and isobutyric acid causing a helix–coil transition in a mixed isobutyric acid/water solvent.
Chiral segregation driven by a dynamical response of the adsorption footprint to the local adsorption environment: bitartrate on Cu(110)
Authors: Darling G. R. , Forster M. , Lin C. , Liu N. , Raval R. , Hodgson A.
Published: February 2017

Bitartrate, a strongly bound chiral modifier, is able to restructure its adsorption footprint on Cu(110) in response to local adsorbates.
Nonstoichiometric copper chalcogenides for photo-activated alkyne/azide cycloaddition
Authors: Zou Hong Yan , Gao Ming Xuan , Yang Tong , Zeng Qiao Ling , Yang Xiao Xi , Liu Feng , Swihart Mark T. , Li Na , Huang Cheng Zhi
Published: February 2017

Cu(i) present in nonstoichiometric copper chalcogenides and associated with copper vacancy defects is released under illumination, enabling efficient photo-activated catalysis of azide–alkyne cycloaddition reactions.
Ethylene oligomerization in metal–organic frameworks bearing nickel(ii) 2,2′-bipyridine complexes
Authors: Gonzalez Miguel I. , Oktawiec Julia , Long Jeffrey R.
Published: February 2017

The metal–organic frameworks Zr6O4(OH)4(bpydc)6 (1; bpydc2− = 2,2′-bipyridine-5,5′-dicarboxylate) and Zr6O4(OH)4(bpydc)0.84(bpdc)5.16 (2; bpdc2− = biphenyl-4,4′-dicarboxylate) were readily metalated with Ni(DME)Br2 (DME = dimethoxyethane) to produce the corresponding metalated frameworks 1(NiBr2)6 and 2(NiBr2)0.84. Both nickel(ii)-containing frameworks catalyze the oligomerization of ethylene in the presence of Et2AlCl. In these systems, the pore environment around the active nickel sites significantly influences their selectivity for formation of oligomers over polymer. Specifically, the single-crystal structure of 1(NiBr2)5.64 reveals that surrounding metal–linker complexes enforce a steric environment on each nickel site that causes polymer formation to become favorable. Minimizing this steric congestion by isolating the nickel(ii) bipyridine complexes in the mixed-linker framework 2(NiBr2)0.84 markedly improves both the catalytic activity and selectivity for oligomers. Furthermore, both frameworks give product mixtures that are enriched in shorter olefins (C4–10), leading to deviations from the expected Schulz–Flory distribution of oligomers. Although these deviations indicate possible pore confinement effects on selectivity, control experiments using the nickel-treated biphenyl framework Zr6O4(OH)4(bpdc)6(NiBr2)0.14 (3(NiBr2)0.14) reveal that they likely arise at least in part from the presence of nickel species that are not ligated by bipyridine within 1(NiBr2)5.64 and 2(NiBr2)0.84.
Ruthenium-catalyzed meta-selective C–H sulfonation of azoarenes with arylsulfonyl chlorides
Authors: Li Gang , Lv Xulu , Guo Kexiao , Wang Ya , Yang Suling , Yu Liuyang , Yu Yantang , Wang Junjie
Published: February 2017

Ruthenium-catalyzedmeta-selective C–H sulfonation of azoarenes with arylsulfonyl chloridesviaa five-membered ruthenacycle complex.
Immobilization of Amano lipase from Pseudomonas fluorescens on silk fibroin spheres: an alternative protocol for the enantioselective synthesis of halohydrins
Authors: Ferreira Irlon M. , Yoshioka Sergio A. , Comasseto João V. , Porto André L. M.
Published: February 2017

Amano lipase from Pseudomonas fluorescens immobilized on silk fibroin spheres and used in the enzymatic kinetic resolution of halohydrins, to obtain optically active epoxides, important precursors in the synthesis of antifungal azoles.
Correction: Synthesis and characterization of TPGS–gemcitabine prodrug micelles for pancreatic cancer therapy
Authors: Khare Vaibhav , Sakarchi Wejdan Al. , Gupta Prem N. , Curtis Anthony D. M. , Hoskins Clare
Published: February 2017

Correction for ‘Synthesis and characterization of TPGS–gemcitabine prodrug micelles for pancreatic cancer therapy’ by Vaibhav Khare et al., RSC Adv., 2016, 6, 60126–60137.
Novel photoanode architecture for optimal dye-sensitized solar cell performance and its small cell module study
Authors: Susmitha K. , Kumar M. Naresh , Gurulakshmi M. , Giribabu L. , Raghavender M.
Published: February 2017

Present work demonstrates a novel photoanode for dye sensitized solar cell, consists of a top active layer is developed over scatter layer, promote improved usage of sunlight for conversion into electricity.
Nickel–cobalt oxides supported on Co/N decorated graphene as an excellent bifunctional oxygen catalyst
Authors: Hao Yongchao , Xu Yuqi , Liu Junfeng , Sun Xiaoming
Published: February 2017

A nickel–cobalt oxides supported on Co/N decorated graphene composite was prepared with excellent bifunctional oxygen catalytic performance.
Highly accurate and power‐efficient battery charger with charging current compensator for wearable devices
Authors: Jung Y.‐H. , Hong S.‐K. , Kwon O.‐K.
Published: February 2017

Highly accurate and power‐efficient hybrid battery charger is proposed which includes the switching and linear chargers as well as a charging current compensator. The proposed current compensator operates the switching charger in the constant current (CC) mode to achieve high power efficiency and to improve the charging current accuracy with a small‐sized inductor. It also operates the linear charger to minimise the charging current variation in the trickle current (TC) mode and to reduce the battery charging voltage error in the constant voltage (CV) mode. The proposed battery charger was fabricated using a 0.18 μm CMOS process and occupies a chip area of 1.63 mm2. The measurement results show that the proposed battery charger achieves a charging current accuracy of 96.2% in the CC mode, which is improved by 15.8% at a target current of 500 mA, as well as a power dissipation of 0.26 W. In addition, the charging current variation and charging voltage error are measured to be <2 mAP−P in the TC mode and 0.48% in the CV mode.
Design of frequency reconfigurable multiband compact antenna using two PIN diodes for WLAN/WiMAX applications
Authors: Abdulraheem Yasir I. , Oguntala George A. , Abdullah Abdulkareem S. , Mohammed Husham J. , Ali Ramzy A. , Abd‐Alhameed Raed A. , Noras James M.
Published: February 2017

In this study, the authors present a simple reconfigurable multiband antenna with two PIN diode switches for worldwide interoperability for microwave access (WiMAX)/wireless local area networks (WLAN) applications. The antenna permits reconfigurable switching in up to ten frequency bands between 2.2 and 6 GHz, with relative impedance bandwidths of around 2.5 and 8%. The proposed antenna has been simulated using computer simulation technology microwave studio software and fabricated on an FR‐4 substrate. It is compact, with an area of 50 × 45 mm2, and has a slotted ground substrate. Both measured and simulated return loss characteristics of the optimised antenna show that it satisfies the requirement of 2.4/5.8 GHz WLAN and 3.5 GHz WiMAX antenna applications. Moreover, there is good agreement between the measured and simulated results in terms of radiation pattern and gain.
Titanium Mesh Nasal Repair without Nasal Lining
Authors: Kao Katherine , Chen Collin , Gross Jennifer , Hahn Samuel , Chi John , Branham Gregory , Zenga Joseph
Published: February 2017

The objective of this study was to describe outcomes for patients who underwent titanium mesh reconstruction of full-thickness nasal defects without internal lining repair. This is a retrospective cohort study. Patients with through-and-through nasal defects were identified at a single academic institution between 2008 and 2016. Nasal reconstruction was performed with either titanium mesh and external skin reconstruction without repair of the intranasal lining or traditional three-layer closure. Five patients underwent titanium mesh reconstruction and 11 underwent traditional three-layer repair. Median follow-up was 11 months (range, 2–66 months). The only significant difference between groups was older age in patients undergoing titanium reconstruction (mean, 81 vs. 63 years; difference of 18; 95% confidence interval [CI], 4–32 years). Defect extent including overall size and structures removed was similar between groups (p > 0.05). Paramedian forehead flap was the most common external reconstruction in both groups (100% for titanium mesh and 73% for three-layer closure). Time under anesthesia was significantly shorter for titanium mesh reconstruction (median, 119 vs. 314 minutes; difference of 195; 95% CI, 45–237). Estimated blood loss and length of hospital stay were similar between groups (p > 0.05). Complication rates were substantial although not significantly different, 40 and 36% in titanium and three-layer reconstruction, respectively (p > 0.05). All patients with complications after titanium reconstruction had prior or postoperative radiotherapy. Titanium mesh reconstruction of through-and-through nasal defects can successfully be performed without reconstruction of the intranasal lining, significantly decreasing operative times. This reconstructive technique may not be suitable for patients who undergo radiotherapy.
Principles of Nasal Reconstruction
Authors: Branham Gregory , Spataro Emily
Published: February 2017

The rise in cutaneous malignancies over the past 20 years has led to significant advances in reconstructing the nose from an aesthetic and functional standpoint. The principles of nasal reconstruction center on application of the nasal subunit principle, three-layered reconstruction, nasal skin characteristics, and patient factors. Reconstructive planning starts with proper defect analysis, followed by application of the reconstructive ladder for soft-tissue repair, adequate structural support, and repair of nasal lining deficits. Optimal reconstructive methods depend on the location and size of the defect. Finally, refinement of the reconstruction is achieved through dermabrasion, scar revision, and flap thinning techniques.
Edge anisotropy and the geometric perspective on flow networks
Authors: Molkenthin Nora , Kutza Hannes , Tupikina Liubov , Marwan Norbert , Donges Jonathan F. , Feudel Ulrike , Kurths Jürgen , Donner Reik V.
Published: February 2017

Spatial networks have recently attracted great interest in various fields of research. While the traditional network-theoretic viewpoint is commonly restricted to their topological characteristics (often disregarding the existing spatial constraints), this work takes a geometric perspective, which considers vertices and edges as objects in a metric space and quantifies the corresponding spatial distribution and alignment. For this purpose, we introduce the concept of edge anisotropy and define a class of measures characterizing the spatial directedness of connections. Specifically, we demonstrate that the local anisotropy of edges incident to a given vertex provides useful information about the local geometry of geophysical flows based on networks constructed from spatio-temporal data, which is complementary to topological characteristics of the same flow networks. Taken both structural and geometric viewpoints together can thus assist the identification of underlying flow structures from observations of scalar variables.
Clustering coefficient and periodic orbits in flow networks
Authors: Rodríguez-Méndez Victor , Ser-Giacomi Enrico , Hernández-García Emilio
Published: February 2017

We show that the clustering coefficient, a standard measure in network theory, when applied to flow networks, i.e., graph representations of fluid flows in which links between nodes represent fluid transport between spatial regions, identifies approximate locations of periodic trajectories in the flow system. This is true for steady flows and for periodic ones in which the time interval τ used to construct the network is the period of the flow or a multiple of it. In other situations, the clustering coefficient still identifies cyclic motion between regions of the fluid. Besides the fluid context, these ideas apply equally well to general dynamical systems. By varying the value of τ used to construct the network, a kind of spectroscopy can be performed so that the observation of high values of mean clustering at a value of τ reveals the presence of periodic orbits of period 3τ, which impact phase space significantly. These results are illustrated with examples of increasing complexity, namely, a steady and a periodically perturbed model two-dimensional fluid flow, the three-dimensional Lorenz system, and the turbulent surface flow obtained from a numerical model of circulation in the Mediterranean sea.
Spatio-temporal organization of dynamics in a two-dimensional periodically driven vortex flow: A Lagrangian flow network perspective
Authors: Lindner Michael , Donner Reik V.
Published: February 2017

We study the Lagrangian dynamics of passive tracers in a simple model of a driven two-dimensional vortex resembling real-world geophysical flow patterns. Using a discrete approximation of the system's transfer operator, we construct a directed network that describes the exchange of mass between distinct regions of the flow domain. By studying different measures characterizing flow network connectivity at different time-scales, we are able to identify the location of dynamically invariant structures and regions of maximum dispersion. Specifically, our approach allows us to delimit co-existing flow regimes with different dynamics. To validate our findings, we compare several network characteristics to the well-established finite-time Lyapunov exponents and apply a receiver operating characteristic analysis to identify network measures that are particularly useful for unveiling the skeleton of Lagrangian chaos.
Anomalous structural response of nematic colloidal platelets subjected to large amplitude stress oscillations
Authors: Korculanin O. , Hermida-Merino D. , Hirsemann H. , Struth B. , Rogers S. A. , Lettinga M. P.
Published: February 2017

Time-resolved small angle X-ray measurements are used to investigate the dynamic response to nonlinear oscillatory stresses and strains of a nematic dispersion of colloidal gibbsite platelets. We track the full 3D rotational motion of the director by employing plate-plate and concentric cylinder Couette geometries as well as a vertical X-ray beam. Under nonlinear oscillatory stress, we observe strong offsets in the rheological response as well as asymmetrical behavior in the microscopic structural response. This offset and asymmetry are connected to the yielding behavior of the platelets. By increasing the stress amplitude, we observed that the offset of the rheological response diminishes and the microscopic response becomes more symmetric; however, this strongly depends on the frequency of the stress input, and hence the time necessary for the system to yield.
Improved method for generating exchange-correlation potentials from electronic wave functions
Authors: Ospadov Egor , Ryabinkin Ilya G. , Staroverov Viktor N.
Published: February 2017

Ryabinkin, Kohut, and Staroverov (RKS) [Phys. Rev. Lett. 115, 083001 (2015)] devised an iterative method for reducing many-electron wave functions to Kohn–Sham exchange-correlation potentials, vXC(𝐫). For a given type of wave function, the RKS method is exact (Kohn–Sham-compliant) in the basis-set limit; in a finite basis set, it produces an approximation to the corresponding basis-set-limit vXC(𝐫). The original RKS procedure works very well for large basis sets but sometimes fails for commonly used (small and medium) sets. We derive a modification of the method’s working equation that makes the RKS procedure robust for all Gaussian basis sets and increases the accuracy of the resulting exchange-correlation potentials with respect to the basis-set limit.
Shear-thinning of molecular fluids in Couette flow
Authors: Raghavan Bharath V. , Ostoja-Starzewski Martin
Published: February 2017

We use non-equilibrium molecular dynamics simulations, the Boltzmann equation, and continuum thermomechanics to investigate and characterize the shear-thinning behavior of molecular fluids undergoing Couette flow, interacting via a Lennard-Jones (LJ) potential. In particular, we study the shear-stress under steady-state conditions and its dependency on fluid density and applied shear-strain rate. Motivated by kinetic theory, we propose a rheological equation of state that fits observed system responses exceptionally well and captures the extreme shear-thinning effect. We notice that beyond a particular strain-rate threshold, the fluid exhibits shear-thinning, the degree of which is dependent on the density and temperature of the system. In addition, we obtain a shear-rate dependent model for the viscosity which matches the well established Cross viscosity model. We demonstrate how this model arises naturally from the Boltzmann equation and possesses an inherent scaling parameter that unifies the rheological properties of the LJ fluid. We compare our model with those in the literature. Finally, we formulate a dissipation function modeling the LJ fluid as a quasilinear fluid.
A millikelvin all-fiber cavity optomechanical apparatus for merging with ultra-cold atoms in a hybrid quantum system
Authors: Zhong H. , Fläschner G. , Schwarz A. , Wiesendanger R. , Christoph P. , Wagner T. , Bick A. , Staarmann C. , Abeln B. , Sengstock K. , Becker C.
Published: February 2017

We describe the construction of an apparatus designed to realize a hybrid quantum system comprised of a cryogenically cooled mechanical oscillator and ultra-cold 87Rb atoms coupled via light. The outstanding feature of our instrument is an in situ adjustable asymmetric all-fiber membrane-in-the-middle cavity located inside an ultra-high vacuum dilution refrigerator based cryostat. We show that Bose-Einstein condensates of N=2×106 atoms can be produced in less than 20 s and demonstrate a single photon optomechanical coupling strength of g0=2π×9 kHz employing a high-stress Si3N4 membrane with a mechanical quality factor Qm>107 at a cavity setup temperature of TMiM = 480 mK.
Experimental evidence of directivity-enhancing mechanisms in nonlinear lattices
Authors: Ganesh R. , Gonella Stefano
Published: February 2017

In this letter, we experimentally investigate the directional characteristics of propagating, finite-amplitude wave packets in lattice materials, with an emphasis on the functionality enhancement due to the nonlinearly generated higher harmonics. To this end, we subject a thin, periodically perforated sheet to out-of-plane harmonic excitations, and we design a systematic measurement and data processing routine that leverages the full-wavefield reconstruction capabilities of a laser vibrometer to precisely delineate the effects of nonlinearity. We demonstrate experimentally that the interplay of dispersion, nonlinearity, and modal complexity which is involved in the generation and propagation of higher harmonics gives rise to secondary wave packets with characteristics that conform to the dispersion relation of the corresponding linear structure. Furthermore, these nonlinearly generated wave features display modal and directional characteristics that are complementary to those exhibited by the fundamental harmonic, thus resulting in an augmentation of the functionality landscape of the lattice. These results provide a proof of concept for the possibility to engineer the nonlinear wave response of mechanical metamaterials through a geometric and topological design of the unit cell.
A wind-powered one-way bistable medium with parity effects
Authors: Rosenberger Tessa , Schattgen Graham , King-Smith Matthew , Shrestha Prakrit , Maxted Katsuo J. , Lindner John F.
Published: February 2017

We describe the design, construction, and dynamics of low-cost mechanical arrays of 3D-printed bistable elements whose shapes interact with wind to couple them one-way. Unlike earlier hydromechanical unidirectional arrays, our aeromechanical one-way arrays are simpler, easier to study, and exhibit a broader range of phenomena. Solitary waves or solitons propagate in one direction at speeds proportional to wind speeds. Periodic boundaries enable solitons to annihilate in pairs in arrays with an even number of elements. Solitons propagate indefinitely in odd arrays that frustrate pairing. Large noise spontaneously creates soliton-antisoliton pairs. Soliton annihilation times increase quadratically with initial separations, as expected for random-walk models of soliton collisions.
Consensus in averager-copier-voter networks of moving dynamical agents
Authors: Shang Yilun
Published: February 2017

This paper deals with a hybrid opinion dynamics comprising averager, copier, and voter agents, which ramble as random walkers on a spatial network. Agents exchange information following some deterministic and stochastic protocols if they reside at the same site in the same time. Based on stochastic stability of Markov chains, sufficient conditions guaranteeing consensus in the sense of almost sure convergence have been obtained. The ultimate consensus state is identified in the form of an ergodicity result. Simulation studies are performed to validate the effectiveness and availability of our theoretical results. The existence/non-existence of voters and the proportion of them are unveiled to play key roles during the consensus-reaching process.
Communication: Neutral atom imaging using a pulsed electromagnetic lens
Authors: Gardner Jamie R. , Anciaux Erik M. , Raizen Mark G.
Published: February 2017

We report on progress towards a neutral atom imaging device that will be used for chemically sensitive surface microscopy and nanofabrication. Our novel technique for improving refractive power and correcting chromatic aberration in atom lenses is based on a fundamental paradigm shift from continuous-beam focusing to a pulsed, three-dimensional approach. Simulations of this system suggest that it will pave the way toward the long-sought goal of true atom imaging on the nanoscale. Using a prototype lens with a supersonic beam of metastable neon, we have imaged complex patterns with lower distortion and higher resolution than has been shown in any previous experiment. Comparison with simulations corroborates the underlying theory and encourages further refinement of the process.
Species transport on the target during high power impulse magnetron sputtering
Authors: Layes V. , Monje S. , Corbella C. , Trieschmann J. , de los Arcos T. , von Keudell A.
Published: February 2017

High Power Impulse Magnetron Sputtering (HiPIMS) is a prominent technique to deposit superior materials due to the very energetic growth flux. The origin of this energetic growth flux is believed to be an electric potential structure inside localized ionization zones, the so-called spokes, in the HiPIMS plasma, which rotate in the E × B direction along the racetrack. The measurement of this electric potential or of the electric fields surrounding this ionization zone is extremely challenging due to the very high local power density that obstructs any traditional probe diagnostics. Here, we use a marker technique on the magnetron target to analyze the lateral transport of a target material on a HiPIMS target. We show that the target material is predominantly transported in the E × B direction irrespective of the presence of spokes. However, only when spokes are present, we observe also an enhanced transport in the opposite E × B direction. This is explained by the large electric field at the trailing edges of spokes.
The effects of magnesium doping on the modal loss in AlGaN-based deep UV lasers
Authors: Martens M. , Kuhn C. , Simoneit T. , Hagedorn S. , Knauer A. , Wernicke T. , Weyers M. , Kneissl M.
Published: February 2017

Absorption losses in the Mg-doped layers significantly contribute to the modal losses in group-III-nitride-based lasers. In this paper, we investigate the influence of Mg-doping on the modal absorption of optically pumped UVC lasers grown on epitaxially laterally overgrown AlN/sapphire substrates with an averaged threading dislocation density of 1 × 109 cm–2. By varying the setback of the Mg-doping (∼1 × 1020 cm−3) within the upper Al0.70Ga0.30N waveguide layer, the overlap of the optical mode with the Mg-doped region increases. For all structures, internal losses were derived from gain spectra obtained by the variable stripe length method. The internal losses increase from 10 cm−1 for lasers without Mg-doping to 28 cm−1 for lasers with a fully Mg-doped upper waveguide layer. The overlap of the optical mode with the Mg-doped waveguide ΓMg clearly correlates with the modal losses. This allows to calculate the Mg-induced losses in current injection laser diodes by αmodMg=ΓMg×50 cm−1.
The structure of liquid UO2−x in reducing gas atmospheres
Authors: Alderman O. L. G. , Benmore C. J. , Weber J. K. R. , Skinner L. B. , Tamalonis A. J. , Sendelbach S. , Hebden A. , Williamson M. A.
Published: February 2017

High energy X-ray diffraction experiments performed on hypostoichiometric UO2−x liquids in reducing gas mixtures of 95%Ar:5%CO and 95%Ar:5%H2 are compared to that conducted in a pure Ar atmosphere [Skinner et al., Science 346, 984 (2014)]. The measurements are pertinent to severe accident scenarios at nuclear reactors, where core melts can encounter reducing conditions and further shed light on the oxide chemistry of the low valence states of uranium, particularly U(III), which become stable only at very high temperatures and low oxygen potentials. The radioactive samples were melted by floating small spheres of material using an aerodynamic levitator and heating with a laser beam. In the more reducing environments, a 1.7% shift to lower Q-values is observed in the position of the principal peak of the measured X-ray structure factors, compared to the more oxidizing Ar environment. This corresponds to an equivalent elongation in the U-U nearest neighbor distances and the U-U periodicity. The U-O peak (modal) bond-length, as measured from the real-space total correlation functions, is also observed to expand by 0.9–1.6% under reducing conditions, consistent with the presence of 15–27% U3+ cations, assuming constant U-O coordination number. The slightly larger U-U elongation, as compared to the U-O elongation, is interpreted as a slight increase in U-O-U bond angles. Difficulties concerning the determination of the hypostoichiometry, x, are discussed, along with the future directions for related research.
Phenotypic and genetic evidence for a unifactorial structure of spatial abilities
Authors: Rimfeld Kaili , Shakeshaft Nicholas G. , Malanchini Margherita , Rodic Maja , Selzam Saskia , Schofield Kerry , Dale Philip S. , Kovas Yulia , Plomin Robert
Published: February 2017

Significance

Spatial ability is a strong predictor of several important outcomes, including success in science, technology, engineering, and mathematics (STEM) subjects and careers. This ability is widely believed to be multifactorial, with numerous components and subdomains, such as “mental rotation,” “scanning,” and “mechanical reasoning.” This large twin study allows the genetic and environmental etiology of diverse putative spatial abilities to be explored. The results indicate that this domain is in fact unifactorial, albeit dissociable from general intelligence, suggesting that its structure is much simpler than the sprawling literature suggests. This will aid gene-hunting efforts and allow this ability and its consequences to be examined with greater precision.
C-terminal phosphorylation regulates the kinetics of a subset of melanopsin-mediated behaviors in mice
Authors: Somasundaram Preethi , Wyrick Glenn R. , Fernandez Diego Carlos , Ghahari Alireza , Pinhal Cindy M. , Simmonds Richardson Melissa , Rupp Alan C. , Cui Lihong , Wu Zhijian , Brown R. Lane , Badea Tudor Constantin , Hattar Samer , Robinson Phyllis R.
Published: February 2017

Significance

Intrinsically photosensitive retinal ganglion cells (ipRGCs) respond to light via both rod/cone-driven synaptic input and intrinsic melanopsin-based phototransduction; however, these two pathways are not functionally redundant. Melanopsin-based phototransduction in ipRGCs is critical for the regulation of the pupillary light reflex (PLR), circadian light responses, masking, and sleep. Therefore, understanding the kinetics and shutoff mechanisms for the melanopsin-based photoresponse will reveal how it contributes to a myriad of behaviors that are controlled by ipRGCs. Here, we show that the melanopsin photoresponse shutoff due to C-terminal phosphorylation determines the kinetics of the intrinsic light response in ipRGCs, the PLR, and reentrainment, but not masking and phase angle of entrainment. These results highlight the elaborate control of how the melanopsin photoresponse regulates vastly different light-mediated behaviors.
Robust sampling of decision information during perceptual choice
Authors: Vandormael Hildward , Herce Castañón Santiago , Balaguer Jan , Li Vickie , Summerfield Christopher
Published: February 2017

Significance

When making decisions, humans and other primates move their eyes freely to gather information about their environment. A large literature has explored the factors that determine where the eyes fall during natural scene perception and visual search, concluding that deviant or surprising perceptual information attracts attention and gaze. Here, we describe a sampling policy that paradoxically shows that in a decision-making task, the eyes are attracted to expected rather than unexpected information: When classifying the average of an array of numbers, human observers looked by preference at the numbers that were closest to the mean. This policy drove a behavioral tendency to discount the influence of outliers when making choices, leading to “robust” choices about the stimulus array.
Generalized myoclonic epilepsy with photosensitivity in juvenile dogs caused by a defective DIRAS family GTPase 1
Authors: Wielaender Franziska , Sarviaho Riika , James Fiona , Hytönen Marjo K. , Cortez Miguel A. , Kluger Gerhard , Koskinen Lotta L. E. , Arumilli Meharji , Kornberg Marion , Bathen-Noethen Andrea , Tipold Andrea , Rentmeister Kai , Bhatti Sofie F. M. , Hülsmeyer Velia , Boettcher Irene C. , Tästensen Carina , Flegel Thomas , Dietschi Elisabeth , Leeb Tosso , Matiasek Kaspar , Fischer Andrea , Lohi Hannes
Published: February 2017

Significance

Comprehensive clinical, neurological, and genetic examinations characterized a generalized myoclonic epilepsy syndrome with photosensitivity in young Rhodesian Ridgeback dogs. The average age of onset of seizures was 6 mo. Genetic analyses revealed a defective DIRAS family GTPase 1 (
DIRAS1
) gene and protein. DIRAS1 is widely expressed in the brain and has been suggested to regulate acetylcholine release and play a role in neurodevelopment. This study reveals a candidate gene for human myoclonic epilepsies, and a translational model to further elucidate the role of DIRAS1 in neurotransmission and neurodevelopment, and its modulation as a therapeutic option in common epilepsy.
A signal sequence suppressor mutant that stabilizes an assembled state of the twin arginine translocase
Authors: Huang Qi , Alcock Felicity , Kneuper Holger , Deme Justin C. , Rollauer Sarah E. , Lea Susan M. , Berks Ben C. , Palmer Tracy
Published: February 2017

Significance

The twin-arginine translocation (Tat) system transports folded proteins across the prokaryotic inner membrane and the thylakoid membrane of plant chloroplasts. Proteins are targeted to the Tat system by signal peptides containing a highly conserved twin arginine motif. We isolated suppressors in the TatB component that allowed a Tat substrate with a defective twin arginine motif to be transported. The strongest of these suppressors, TatB F13Y, resulted in the constitutive assembly of the Tat translocase in the absence of signal peptide binding. These results show that Tat signal peptides have two separable roles: they target their passenger proteins to the Tat machinery but they also trigger the assembly of the active Tat transporter.
Nondestructive nanostraw intracellular sampling for longitudinal cell monitoring
Authors: Cao Yuhong , Hjort Martin , Chen Haodong , Birey Fikri , Leal-Ortiz Sergio A. , Han Crystal M. , Santiago Juan G. , Paşca Sergiu P. , Wu Joseph C. , Melosh Nicholas A.
Published: February 2017

Significance

Cell content analysis has rapidly become one of the most important new tools for measuring cell phenotype and behavior. However, the central limitation of current sampling technologies is they are destructive and must lyse the cells to measure the contents. This destruction prevents knowledge of prior or future states of the cell, which is particularly important for dynamic cell processes, such as development and differentiation. Here, we show a nondestructive longitudinal sampling and analysis platform that can sample repeatedly and accurately from the same single cell or group of cells over a long time period. We demonstrate sampling of both proteins and mRNA for cell lines as well as human-derived cardiomyocytes and astrocytes.
Architecture and coevolution of allosteric materials
Authors: Yan Le , Ravasio Riccardo , Brito Carolina , Wyart Matthieu
Published: February 2017

Significance

In allosteric proteins, binding a ligand affects activity at a distant site. The physical principles allowing for such an action at a distance are not well understood. Here we introduce a numerical scheme to evolve allosteric materials in which the number of solutions, their spatial architectures, and the correlations among them can be computed. We show that allostery in these materials uses recently discovered elastic edge modes near the active site to transmit information, and that correlations generated during evolution alone can reveal key aspects of this architecture.
Serum-borne bioactivity caused by pulmonary multiwalled carbon nanotubes induces neuroinflammation via blood–brain barrier impairment
Authors: Aragon Mario J. , Topper Lauren , Tyler Christina R. , Sanchez Bethany , Zychowski Katherine , Young Tamara , Herbert Guy , Hall Pamela , Erdely Aaron , Eye Tracy , Bishop Lindsey , Saunders Samantha A. , Muldoon Pretal P. , Ottens Andrew K. , Campen Matthew J.
Published: February 2017

Significance

Inhaled particulates, such as multiwalled carbon nanotubes, can induce neuroinflammatory outcomes. The present study shows that acute neuroinflammation is dependent on the impairment of blood-brain barrier function. Pharmacologic restoration of blood-brain barrier integrity prevented the neuroinflammatory responses to pulmonary multiwalled carbon nanotube exposure. Circulating factors, including possibly thrombospondin-1, recapitulate inflammatory responses in cultured cerebrovascular endothelial cells, suggesting a mechanism for indirect systemic effects of inhaled nanoparticles.
Membrane integration of an essential β-barrel protein prerequires burial of an extracellular loop
Authors: Wzorek Joseph S. , Lee James , Tomasek David , Hagan Christine L. , Kahne Daniel E.
Published: February 2017

Significance

Membrane proteins must be assembled to adopt a mature functional form. Integral membrane proteins with β-barrel structure are found in the outer membranes of Gram-negative bacteria, mitochondria, and chloroplasts. To understand the mechanism by which these proteins are assembled, intermediate states in the process must be accumulated and characterized. Here, we study assembly-defective mutants of the β-barrel protein BamA. Our findings reveal that a highly conserved, hydrophilic loop is buried within the β-barrel of BamA before membrane integration, suggesting that one barrier to assembly is the translocation of hydrophilic sequences across the membrane. The specific interactions we identify in this early assembly step could potentially be used for design of mechanism-based inhibitors with antibiotic activity.
Integrated view of internal friction in unfolded proteins from single-molecule FRET, contact quenching, theory, and simulations
Authors: Soranno Andrea , Holla Andrea , Dingfelder Fabian , Nettels Daniel , Makarov Dmitrii E. , Schuler Benjamin
Published: February 2017

Significance

The dynamics of proteins, which are essential for both folding and function, are known to be strongly dependent on solvent viscosity and friction. However, an increasing number of experiments have demonstrated the importance of a contribution to protein dynamics independent of solvent friction. Such “internal friction” has recently been detected even in unfolded proteins, although they are more expanded and solvent-accessible than folded proteins. Based on two complementary experimental methods, simulations, and theory, our results provide a coherent view of internal friction in unfolded proteins and constitute an important basis for understanding the molecular origin of this phenomenon and its role for the folding of proteins and for the functional dynamics of intrinsically disordered proteins.
Identification of productive and futile encounters in an electron transfer protein complex
Authors: Andrałojć Witold , Hiruma Yoshitaka , Liu Wei-Min , Ravera Enrico , Nojiri Masaki , Parigi Giacomo , Luchinat Claudio , Ubbink Marcellus
Published: February 2017

Significance

Paramagnetic NMR spectroscopy is exquisitely sensitive for sparsely populated states in protein–protein interactions, and thus, it can provide important information on how protein–protein complexes form and evolve toward their productive state. However, the description of ensembles of protein–protein orientations is nontrivial, and great care must be taken when deriving biologically relevant results. We have applied an algorithm that restricts the conformational space sampled by the two partners to the maximum allowed for by the data. These ensembles can then be reduced assuming the principle of scarcity. We found that some states are linked to the main state through electrostatic pathways. Such paths help to identify those minor states that are able to evolve into the productive complex.
PEMapper and PECaller provide a simplified approach to whole-genome sequencing
Authors: Johnston H. Richard , Chopra Pankaj , Wingo Thomas S. , Patel Viren ,   International Consortium on Brain and Behavior in 22q11.2 Deletion Syndrome, Epstein Michael P. , Mulle Jennifer G. , Warren Stephen T. , Zwick Michael E. , Cutler David J. , Morrow Bernice , Emanuel Beverly , McDonald-McGinn Donna M. , Scherer Steve , Bassett Anne , Chow Eva , Vermeesch Joris , Swillen Ann , Gur Raquel , Bearden Carrie , Kates Wendy , Shashi Vandana , Simon Tony , Chopra Pankj , Cubells Joseph , Cutler David J. , Epstein Michael P. , Johnston H. Richard , Mulle Jennifer , Patel Viren , Warren Stephen T. , Wingo Thomas S. , Zwick Michael E. , Campbell Linda , Repetto Gabriela , Vorstman Jacob , Van Amelsvoort Therese , Eliez Stephen , Philip Nicole , Gothelf Doron , Van Den Bree Marianne , Owen Michael , Murphy Clodagh , Murphy Declan , Garcia-Minaur Sixto , Neine-Suner Damian , Murphy Kieran , Armando Marco , Vicari Stefano
Published: February 2017

Significance

PEMapper and PECaller are paired software programs that simplify mapping and variant calling for whole-genome datasets. Whole-genome sequencing data are fast becoming the most natural dataset for all genetic studies. Analysis tools for data at this scale are essential. This manuscript describes tools, which solve the challenges of data analysis at whole-genome scale, using an approach involving 16-mer mapping and SNP calling based on a Pólya–Eggenberger distribution for SNP genotypes. We show that our software package is faster (cheaper to run), uses much less disk space (cheaper to store results), requires no previous knowledge of existing genetic variation (easier to deploy to nonhuman species), and achieves calling results that are as good as Genome Analysis Toolkit best practices.
Two-metal versus one-metal mechanisms of lysine adenylylation by ATP-dependent and NAD
+
-dependent polynucleotide ligases
Authors: Unciuleac Mihaela-Carmen , Goldgur Yehuda , Shuman Stewart
Published: February 2017

Significance

This season marks the 50th anniversary of the discovery of polynucleotide ligases, the
sine qua non
enzymes of nucleic acid repair and the enabling reagents of molecular biology, reported in a series of seminal papers in PNAS. Ligases react with ATP or NAD
+
to form a covalent enzyme–adenylate intermediate in which AMP is linked via a P–N bond to a lysine. This work reports crystal structures of the Michaelis complexes of an exemplary ATP-dependent RNA ligase (bacteriophage T4 Rnl1) and an NAD
+
-dependent DNA ligase (
Escherichia coli
LigA) that illuminate the chemical and structural basis for lysine adenylylation, via distinctive two-metal (ATP) and one-metal (NAD
+
) mechanisms.
Oogenesis and reproductive investment of Atlantic herring are functions of not only present but long-ago environmental influences as well
Authors: dos Santos Schmidt Thassya C. , Slotte Aril , Kennedy James , Sundby Svein , Johannessen Arne , Óskarsson Gudmundur J. , Kurita Yutaka , Stenseth Nils C. , Kjesbu Olav Sigurd
Published: February 2017

Significance

Fish stock advice and management have a focus on protecting the reproductive capacity of a stock. Central to the associated research undertaken is whether spawning stock biomass is a proxy for total egg production. Here we demonstrate for the planktivorous Atlantic herring that the standard use of season-independent potential fecundity formulas may cause flaws in these interpretations. In particular, this would happen when the adults have experienced poor feeding conditions that negatively affect the reservoir of primary oocytes and thereby the future fecundity. Hence, females in excellent condition may show significantly lower-than-expected fecundity that could lead to errors in the judgment of reproductive capacity, especially under “red flag” situations.
Mitochondrial energy deficiency leads to hyperproliferation of skeletal muscle mitochondria and enhanced insulin sensitivity
Authors: Morrow Ryan M. , Picard Martin , Derbeneva Olga , Leipzig Jeremy , McManus Meagan J. , Gouspillou Gilles , Barbat-Artigas Sébastien , Dos Santos Carlos , Hepple Russell T. , Murdock Deborah G. , Wallace Douglas C.
Published: February 2017

Significance

Mitochondrial dysfunction is associated with type II diabetes and metabolic syndrome, but whether it is cause or consequence is debated. By showing that increased mitochondrial respiration can impart glucose tolerance, insulin sensitivity, and resistance to high fat diet (HFD) toxicity, we provide evidence that mitochondria contributes to the etiology of metabolic disease. Inactivation of adenine nucleotide translocator isoform 1 (ANT1) results in proliferation of partially uncoupled muscle mitochondrial respiration, creating a sink for excess calories. Although ANT1-deficient muscle induces expression of
Fg
f21
, FGF21 level is not elevated in blood, and FGF21 and UCP1 mRNAs are not increased in liver or brown adipose tissue (BAT). If increased mitochondrial respiration prevents HFD toxicity, then decreased mitochondrial respiration may contribute to metabolic disease.
Rootworm management: status of GM traits, insecticides and potential new tools.
Authors: Ludwick D. C. , Hibbard B. E.
Published: February 2017

Western corn rootworm (
Diabrotica virgifera virgifera
LeConte) and northern corn rootworm (
Diabrotica barberi
(Smith and Lawrence)) are major pests of maize in the USA. These pests have been managed with a variety of tactics over the last century. Both
Diabrotica
spp. have adapted to crop rotation in different ways in certain regions of the USA as well as to some of the insecticides targeted at them.
D. v. virgifera
has adapted to more of the chemical control measures and transgenic control methods. Discussed in this review are the challenges associated with managing both species, and how current management strategies might be combined and implemented to help manage damage from these species. Also, we discuss the potential for new technologies, such as RNA interference, to be used in the future.
Secondary school leader perceptions about the inclusion of queer materials in the school course curricula
Authors: Steck Andy , Perry David
Published: February 2017

The US school system is dominated by heteronormativity in the formal curriculum that gives preference to binary conceptions of sexuality. School leaders play a role in supporting or disrupting school policies facilitating or inhibiting curricular inclusion of queer content in course materials and an instructional pedagogy that promotes an equitable and inclusive educational process. Using a qualitative design and phenomenographic data analysis method, the purpose of the study was to use a queer/curriculum theory lens to explore secondary level school leaders’ perceptions about their experiences with the inclusion of queer related content in the course curricula in their schools. The sample included seven secondary level educational leaders from schools in a northeastern state in the USA. Using a qualitative design and phenomenographic data analysis methods of in‐depth interviews, five categories of description of leader perceptions were identified: (1) lack of inclusion of queer content in formal state curricula, (2) recognized need for inclusion of queer content in the formal curricula, (3) informal inclusion of queer content in the course curriculum, (4) teacher reluctance to include queer content in the curriculum, and (5) providing teachers with resources and professional development opportunities related to integrating queer content into their course curriculum.
Fragile phagocytes: FMRP positively regulates engulfment activity
Authors: Logan Mary A.
Published: February 2017

Defective immune system function is implicated in autism spectrum disorders, including Fragile X syndrome. In this issue, O’Connor et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201607093) demonstrate that phagocytic activity of systemic immune cells is compromised in a Drosophila melanogaster model of Fragile X, highlighting intriguing new mechanistic connections between FMRP, innate immunity, and abnormal development.
Commentary: An Introduction to Leadership Self-Assessment at the Society of Neurological Surgeons Post-Graduate Year 1 Boot Camp: Observations and Commentary
Authors: Hunt Matthew A. , Heilman Carl B. , Shutran Max , Wu Julian K.
Published: February 2017

Recent trends in graduate medical education have emphasized the mastery of nontechnical skills, especially leadership, for neurosurgical trainees. Accordingly, we introduced leadership development and self-awareness training to interns attending the Society of Neurological Surgeons Post-Graduate Year 1 Boot Camp in the Northeast (New England/New York/New Jersey) region in 2015. Feedback about the session was collected from interns. While neurosurgical interns conveyed a desire to receive more information on improving their leadership skills, most indicated that guidance seemed to be lacking in this critical area. We discuss some of the professional development needs uncovered during this process.