bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron spin resonance identification di-carbon-related centers in irradiated silicon
Authors: Hayashi S. , Saito H. , Itoh K. M. , Vlasenko M. P. , Vlasenko L. S.
Published: February 2018

A previously unreported electron spin resonance (ESR) spectrum was found in γ-ray irradiated silicon by the detection of the change in microwave photoconductivity arising from spin-dependent recombination (SDR). In the specially prepared silicon crystals doped by 13C isotope, a well resolved hyperfine structure of SDR-ESR lines due to the interaction between electrons and two equivalent carbon atoms having nuclear spin I = 1/2 was observed. The Si-KU4 spectrum is described by spin Hamiltonian for spin S = 1 and of g and D tensors of orthorhombic symmetry with principal values g1 = 2.008, g2 = 2.002, and g3 =2.007; and D1 = ± 103 MHz, D2 = ∓170 MHz, and D3 = ± 67 MHz where axes 1, 2, and 3 are parallel to the [11¯0], [110], and [001] crystal axes, respectively. The hyperfine splitting arising from 13C nuclei is about 0.35 mT. A possible microstructure of the detect leading to the Si-KU4 spectrum is discussed.
Three-dimensional finite amplitude electroconvection in dielectric liquids
Authors: Luo Kang , Wu Jian , Yi Hong-Liang , Tan He-Ping
Published: February 2018

Charge injection induced electroconvection in a dielectric liquid lying between two parallel plates is numerically simulated in three dimensions (3D) using a unified lattice Boltzmann method (LBM). Cellular flow patterns and their subcritical bifurcation phenomena of 3D electroconvection are numerically investigated for the first time. A unit conversion is also derived to connect the LBM system to the real physical system. The 3D LBM codes are validated by three carefully chosen cases and all results are found to be highly consistent with the analytical solutions or other numerical studies. For strong injection, the steady state roll, polygon, and square flow patterns are observed under different initial disturbances. Numerical results show that the hexagonal cell with the central region being empty of charge and centrally downward flow is preferred in symmetric systems under random initial disturbance. For weak injection, the numerical results show that the flow directly passes from the motionless state to turbulence once the system loses its linear stability. In addition, the numerically predicted linear and finite amplitude stability criteria of different flow patterns are discussed.
Thermodynamics and proton activities of protic ionic liquids with quantum cluster equilibrium theory
Authors: Ingenmey Johannes , von Domaros Michael , Perlt Eva , Verevkin Sergey P. , Kirchner Barbara
Published: February 2018

We applied the binary Quantum Cluster Equilibrium (bQCE) method to a number of alkylammonium-based protic ionic liquids in order to predict boiling points, vaporization enthalpies, and proton activities. The theory combines statistical thermodynamics of van-der-Waals-type clusters with ab initio quantum chemistry and yields the partition functions (and associated thermodynamic potentials) of binary mixtures over a wide range of thermodynamic phase points. Unlike conventional cluster approaches that are limited to the prediction of thermodynamic properties, dissociation reactions can be effortlessly included into the bQCE formalism, giving access to ionicities, as well. The method is open to quantum chemical methods at any level of theory, but combination with low-cost composite density functional theory methods and the proposed systematic approach to generate cluster sets provides a computationally inexpensive and mostly parameter-free way to predict such properties at good-to-excellent accuracy. Boiling points can be predicted within an accuracy of 50 K, reaching excellent accuracy for ethylammonium nitrate. Vaporization enthalpies are predicted within an accuracy of 20 kJ mol−1 and can be systematically interpreted on a molecular level. We present the first theoretical approach to predict proton activities in protic ionic liquids, with results fitting well into the experimentally observed correlation. Furthermore, enthalpies of vaporization were measured experimentally for some alkylammonium nitrates and an excellent linear correlation with vaporization enthalpies of their respective parent amines is observed.
A theoretical and experimental benchmark study of core-excited states in nitrogen
Authors: Myhre Rolf H. , Wolf Thomas J. A. , Cheng Lan , Nandi Saikat , Coriani Sonia , Gühr Markus , Koch Henrik
Published: February 2018

The high resolution near edge X-ray absorption fine structure spectrum of nitrogen displays the vibrational structure of the core-excited states. This makes nitrogen well suited for assessing the accuracy of different electronic structure methods for core excitations. We report high resolution experimental measurements performed at the SOLEIL synchrotron facility. These are compared with theoretical spectra calculated using coupled cluster theory and algebraic diagrammatic construction theory. The coupled cluster singles and doubles with perturbative triples model known as CC3 is shown to accurately reproduce the experimental excitation energies as well as the spacing of the vibrational transitions. The computational results are also shown to be systematically improved within the coupled cluster hierarchy, with the coupled cluster singles, doubles, triples, and quadruples method faithfully reproducing the experimental vibrational structure.
Structural and electronic properties of isovalent boron atoms in GaAs
Authors: Krammel C. M. , Nattermann L. , Sterzer E. , Volz K. , Koenraad P. M.
Published: February 2018

Boron containing GaAs, which is grown by metal organic vapour phase epitaxy, is studied at the atomic level by cross-sectional scanning tunneling microscopy (X-STM) and spectroscopy (STS). In topographic X-STM images, three classes of B related features are identified, which are attributed to individual B atoms on substitutional Ga sites down to the second layer below the natural {110} cleavage planes. The X-STM contrast of B atoms below the surface reflects primarily the structural modification of the GaAs matrix by the small B atoms. However, B atoms in the cleavage plane have in contrast to conventional isovalent impurities, such as Al and In, a strong influence on the local electronic structure similar to donors or acceptors. STS measurements show that B in the GaAs {110} surfaces gives rise to a localized state short below the conduction band (CB) edge while in bulk GaAs, the B impurity state is resonant with the CB. The analysis of BxGa1–xAs/GaAs quantum wells reveals a good crystal quality and shows that the incorporation of B atoms in GaAs can be controlled along the [001] growth direction at the atomic level. Surprisingly, the formation of the first and fourth nearest neighbor B pairs, which are oriented along the 〈110〉 directions, is strongly suppressed at a B concentration of 1% while the third nearest neighbor B pairs are found more than twice as often than expected for a completely spatially random pattern.
Control of grown-in defects and oxygen precipitates in silicon wafers with DZ-IG structure by ultrahigh-temperature rapid thermal oxidation
Authors: Maeda Susumu , Sudo Haruo , Okamura Hideyuki , Nakamura Kozo , Sueoka Koji , Izunome Koji
Published: February 2018

A new control technique for achieving compatibility between crystal quality and gettering ability for heavy metal impurities was demonstrated for a nitrogen-doped Czochralski silicon wafer with a diameter of 300 mm via ultra-high temperature rapid thermal oxidation (UHT-RTO) processing. We have found that the DZ-IG structure with surface denuded zone and the wafer bulk with dense oxygen precipitates were formed by the control of vacancies in UHT-RTO process at temperature exceeding 1300 °C. It was also confirmed that most of the void defects were annihilated from the sub-surface of the wafer due to the interstitial Si atoms that were generated at the SiO2/Si interface. These results indicated that vacancies corresponded to dominant species, despite numerous interstitial silicon injections. We have explained these prominent features by the degree of super-saturation for the interstitial silicon due to oxidation and the precise thermal properties of the vacancy and interstitial silicon.
B97-3c: A revised low-cost variant of the B97-D density functional method
Authors: Brandenburg Jan Gerit , Bannwarth Christoph , Hansen Andreas , Grimme Stefan
Published: February 2018

A revised version of the well-established B97-D density functional approximation with general applicability for chemical properties of large systems is proposed. Like B97-D, it is based on Becke’s power-series ansatz from 1997 and is explicitly parametrized by including the standard D3 semi-classical dispersion correction. The orbitals are expanded in a modified valence triple-zeta Gaussian basis set, which is available for all elements up to Rn. Remaining basis set errors are mostly absorbed in the modified B97 parametrization, while an established atom-pairwise short-range potential is applied to correct for the systematically too long bonds of main group elements which are typical for most semi-local density functionals. The new composite scheme (termed B97-3c) completes the hierarchy of “low-cost” electronic structure methods, which are all mainly free of basis set superposition error and account for most interactions in a physically sound and asymptotically correct manner. B97-3c yields excellent molecular and condensed phase geometries, similar to most hybrid functionals evaluated in a larger basis set expansion. Results on the comprehensive GMTKN55 energy database demonstrate its good performance for main group thermochemistry, kinetics, and non-covalent interactions, when compared to functionals of the same class. This also transfers to metal-organic reactions, which is a major area of applicability for semi-local functionals. B97-3c can be routinely applied to hundreds of atoms on a single processor and we suggest it as a robust computational tool, in particular, for more strongly correlated systems where our previously published “3c” schemes might be problematic.
First-principles study of direct and indirect optical absorption in BaSnO3
Authors: Kang Youngho , Peelaers Hartwin , Krishnaswamy Karthik , Van de Walle Chris G.
Published: February 2018

We report first-principles results for the electronic structure and the optical absorption of perovskite BaSnO3 (BSO). BSO has an indirect fundamental gap, and hence, both direct and indirect transitions need to be examined. We assess direct absorption by calculations of the dipole matrix elements. The phonon-assisted indirect absorption spectrum at room temperature is calculated using a quasiclassical approach. Our analysis provides important insights into the optical properties of BSO and addresses several inconsistencies in the results of optical absorption experiments. We shed light on the variety of bandgap values that have been previously reported, concluding that the indirect gap is 2.98 eV and the direct gap is 3.46 eV.
Excitation of nonaxisymmetric perturbations by the axisymmetric explosive magnetorotational instability in Keplerian discs
Authors: Shtemler Yu. , Mond M. , Liverts E.
Published: February 2018

The excitation of nonaxisymmetric quasi-resonant triads by clustering around a dominant axisymmetric explosively unstable magnetorotational instability (MRI) in Keplerian discs is investigated. Clustering, namely, the mutual interactions of a large number of quasi-resonant triads that are connected by a single dominant explosively unstable axisymmetric triad, is invoked in order to provide a viable mechanism for the stabilization of the explosive nature of the latter. The results, however, are of wider scope as the proposed clustering scenario also provides a strong mechanism for the excitation of high-amplitude nonaxisymmetric perturbations. The latter play a major role in the nonlinear evolution of the MRI on the route to fully developed turbulence.
Influence of complex interfacial rheology on the thermocapillary migration of a surfactant-laden droplet in Poiseuille flow
Authors: Das Sayan , Chakraborty Suman
Published: February 2018

The effect of surface viscosity on the motion of a surfactant-laden droplet in the presence of a non-isothermal Poiseuille flow is studied, both analytically and numerically. The presence of bulk-insoluble surfactants along the droplet surface results in interfacial shear and dilatational viscosities. This, in turn, is responsible for the generation of surface-excess viscous stresses that obey the Boussinesq-Scriven constitutive law for constant values of surface shear and dilatational viscosities. The present study is primarily focused on finding out how this confluence can be used to modulate droplet dynamics in the presence of Marangoni stress induced by nonuniform distribution of surfactants and temperature along the droplet surface, by exploiting an intricate interplay of the respective forcing parameters influencing the interfacial stresses. Under the assumption of negligible fluid inertia and thermal convection, the steady-state migration velocity of a non-deformable spherical droplet, placed at the centerline of an imposed unbounded Poiseuille flow, is obtained for the limiting case when the surfactant transport along the interface is dominated by surface diffusion. Our analysis proves that the droplet migration velocity is unaffected by the shear viscosity whereas the dilatational viscosity has a significant effect on the same. The surface viscous effects always retard the migration of a surfactant-laden droplet when the temperature in the far-field increases in the direction of the imposed flow although the droplet always migrates towards the hotter region. On the contrary, if a large temperature gradient is applied in a direction opposite to that of the imposed flow, the direction of droplet migration gets reversed. However, for a sufficiently high value of dilatational surface viscosity, the direction of droplet migration reverses. For the limiting case in which the surfactant transport along the droplet surface is dominated by surface convection, on the other hand, surface viscosities do not have any effect on the motion of the droplet. These results are likely to have far-reaching consequences in designing an optimal migration path in droplet-based microfluidic technology.
Energy decomposition analysis for exciplexes using absolutely localized molecular orbitals
Authors: Ge Qinghui , Mao Yuezhi , Head-Gordon Martin
Published: February 2018

An energy decomposition analysis (EDA) scheme is developed for understanding the intermolecular interaction involving molecules in their excited states. The EDA utilizes absolutely localized molecular orbitals to define intermediate states and is compatible with excited state methods based on linear response theory such as configuration interaction singles and time-dependent density functional theory. The shift in excitation energy when an excited molecule interacts with the environment is decomposed into frozen, polarization, and charge transfer contributions, and the frozen term can be further separated into Pauli repulsion and electrostatics. These terms can be added to their counterparts obtained from the ground state EDA to form a decomposition of the total interaction energy. The EDA scheme is applied to study a variety of systems, including some model systems to demonstrate the correct behavior of all the proposed energy components as well as more realistic systems such as hydrogen-bonding complexes (e.g., formamide-water, pyridine/pyrimidine-water) and halide (F−, Cl−)-water clusters that involve charge-transfer-to-solvent excitations.
Fractional electrical dimensionality in the spin solid phase of artificial honeycomb lattice
Authors: Dahal A. , Summers B. , Singh D. K.
Published: February 2018

Two-dimensional artificial magnetic honeycomb lattices are at the forefront of research on unconventional magnetic materials. Among the many emergent magnetic phases that are predicted to arise as a function of temperature, the low temperature spin solid phase with zero magnetization and entropy is of special importance. Here, we report an interesting perspective to the consequence of spin solid order in an artificial honeycomb lattice of ultra-small connected elements using electrical dimensionality analysis. At low temperature, T ≤ 30 K, the system exhibits a very strong insulating characteristic. The electrical dimensionality analysis of the experimental data reveals a fractional dimensionality of d = 0.6(0.04) in the spin solid phase of honeycomb lattice at low temperature. The much smaller electrical dimension in the spin solid phase, perhaps, underscores the strong insulating behavior in this system. Also, the fractional dimensionality in an otherwise two-dimensional system suggests a non-surface-like electrical transport at low temperature in an artificial honeycomb lattice.
A comprehensive study of g-factors, elastic, structural and electronic properties of III-V semiconductors using hybrid-density functional theory
Authors: Bastos Carlos M. O. , Sabino Fernando P. , Sipahi Guilherme M. , Da Silva Juarez L. F.
Published: February 2018

Despite the large number of theoretical III-V semiconductor studies reported every year, our atomistic understanding is still limited. The limitations of the theoretical approaches to yield accurate structural and electronic properties on an equal footing, is due to the unphysical self-interaction problem that mainly affects the band gap and spin-orbit splitting (SOC) in semiconductors and, in particular, III-V systems with similar magnitude of the band gap and SOC. In this work, we report a consistent study of the structural and electronic properties of the III-V semiconductors by using the screening hybrid-density functional theory framework, by fitting the α parameters for 12 different III-V compounds, namely, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, and InSb, to minimize the deviation between the theoretical and experimental values of the band gap and SOC. Structural relaxation effects were also included. Except for AlP, whose α = 0.127, we obtained α values that ranged from 0.209 to 0.343, which deviate by less than 0.1 from the universal value of 0.25. Our results for the lattice parameter and elastic constants indicate that the fitting of α does not affect those structural parameters when compared with the HSE06 functional, where α = 0.25. Our analysis of the band structure based on the k ⋅ p method shows that the effective masses are in agreement with the experimental values, which can be attributed to the simultaneous fitting of the band gap and SOC. Also, we estimate the values of g-factors, extracted directly from the band structure, which are close to experimental results, which indicate that the obtained band structure produced a realistic set of k ⋅ p parameters.
Dynamic analysis of material ejection from cathodic metal nano-tips due to local heating and field generated stress
Authors: Qiu X. , Joshi R. P.
Published: February 2018

The potential for explosive cathode emission due to nanoprotrusions subjected to Maxwell stress and heating from strong electric fields is probed self-consistently based on non-equilibrium molecular-dynamics. The focus is on determining the electric field magnitudes that could lead to material ejection, assessing dependencies of the instability on the nanoprotrusion height and cross-sectional area, and the role of time-dependent thermal conductivity and local temperature changes. Our results indicate that large aspect ratios would facilitate mass ejection, with protrusion break up occurring over times in the 25 ns range, in agreement with experimental reports on explosive emission.
Nearly temperature-independent ultraviolet light emission intensity of indirect excitons in hexagonal BN microcrystals
Authors: Chichibu Shigefusa F. , Ishikawa Youichi , Kominami Hiroko , Hara Kazuhiko
Published: February 2018

The radiative performance of hexagonal boron nitride (h-BN) was assessed by the spatio-time-resolved luminescence measurements on its microcrystals (MCs) annealed in an O2 gas ambient. The MCs exhibited distinct deep ultraviolet luminescence peaks higher than 5.7 eV, although h-BN is an indirect bandgap semiconductor. The result indicates a strong interaction between the indirect excitons (iXs) and LO/TO (and LA/TA) phonons at T points of the Brillouin zone. Such phonon replicas of free iXs and a luminescence band at 4.0 eV showed negligible thermal quenching, most probably assisted by the strong excitonic effect, enhanced phonon scattering, and formation of a surface BxOy layer that prevents excitons from surface recombination by the thermal excitation. Conversely, the luminescence band between 5.1 and 5.7 eV, which seems to consist of LO/TO phonon replicas of iXs localized at a certain structural singularity that are further scattered by multiple TO phonons at K points and another two emission peaks that originate from the singularity, showed the thermal quenching. In analogy with GaN and AlGaN, cation vacancy complexes most likely act as native nonradiative recombination centers (NRCs). In the present case, vacancy complexes that contain a boron vacancy (VB), such as divacancies with a nitrogen vacancy (VN), VBVN, are certain to act as NRCs. In this instance, iXs delocalized from the singularity are likely either captured by NRCs or the origin of the 4.0 eV-band; the latter is assigned to originate from a carbon on the N site or a complex between VB and an oxygen on the N site.
A practical double-sided frequency selective surface for millimeter-wave applications
Authors: Mohyuddin Wahab , Woo Dong Sik , Choi Hyun Chul , Kim Kang Wook
Published: February 2018

Analysis, design, and implementation of a practical, high-rejection frequency selective surface (FSS) are presented in this paper. An equivalent circuit model is introduced for predicting the frequency response of the FSS. The FSS consists of periodic square loop structures fabricated on both sides of the thin dielectric substrate by using the low-cost chemical etching technique. The proposed FSS possesses band-stop characteristics and is implemented to suppress the 170 GHz signal with attenuation of more than 45 dB with insensitivity to an angle of incident plane wave over 20°. Good agreement is observed among calculated, simulated, and measured results. The proposed FSS filter can be used in various millimeter-wave applications such as the protection of imaging diagnostic systems from high spurious input power.
Simulation reproduces decades-old hexagonal cell pattern observed in an electroconvection system
Authors: Kim Meeri
Published: February 2018

First observed almost 40 years ago, the hexagonal cell flow pattern in an electroconvection system is predicted using numerical simulation for the first time.
Systematics and biogeography of Spinoctenus, a new genus of wandering spider from Colombia (Ctenidae)
Authors: Hazzi Nicolas A. , Polotow Daniele , Brescovit Antonio D. , González-Obando Ranulfo , Simó Miguel
Published: February 2018

Among ctenid spiders, ctenines comprise the most diverse subfamily. In this study, a new genus of Cteninae, Spinoctenus, is proposed to include the type species S. yotoco, sp. nov. Ten new species are also described: S. escalerete, S. pericos, S. eberhardi, S. spinosus, S. stephaniae, S. nambi, S. florezi, S. tequendama, S. chocoensis and S. flammigerus. Results of the parsimony and Bayesian phylogenetic analyses using morphological and behavioural characters indicate the monophyly of this genus, closely related to Phoneutria Perty, 1883 and Ctenus Walckenaer, 1805. This genus can be distinguished from the remaining Ctenidae by three unambiguous synapomorphies: embolus with folded process, tegulum with median process, and RTA curved internally close to the cymbium. A dispersal-vicariance biogeographical analysis of the genus in the Andean and Chocó regions indicates the origin of Spinoctenus in the Western and Central Andean Cordilleras. From this region, three events of dispersal occurred to the other regions (one to the Chocó and two to the Eastern Cordillera), which were subsequently followed by three events of vicariance, suggesting that dispersal and vicariance were equally important in shaping the current distribution patterns of Spinoctenus species. The discovery of this new genus containing a large number of new species in the Andean and Chocó regions highlights the current poor knowledge of the Colombian biodiversity. http://zoobank.org/urn:lsid:zoobank.org:pub:A7DA044C-8A59-4FAE-8F3B-00D3D2498820
Further polyphyly of pinnotheroid crabs: the molecular phylogenetic position of the polychaete-associated Aphanodactylidae
Authors: Tsang Ling Ming , Ahyong Shane T. , Shih Hsi-Te , Ng Peter K. L.
Published: February 2018

Pea crabs of the superfamily Pinnotheroidea De Haan, 1833 are known for their obligate commensal relationships with other marine invertebrates. The concomitant specialisations and adaptations of pinnotheroids have resulted in superficially similar body forms that include a high degree of structural reduction. This has confounded interpretation of their phylogenetic position in the Brachyura and interrelationships within Pinnotheroidea, though all were nevertheless believed to be united by a monophyletic origin of obligate commensalism. The family Aphanodactylidae Ahyong & Ng, 2009 was proposed for a group of genera associated with tube-dwelling polychaetes formerly classified in Pinnotheridae, and provisionally retained in the Pinnotheroidea. We investigated the phylogenetic position of Aphanodactylidae using molecular data from three markers (mitochondrial 12S and 16S rRNAs, and nuclear histone H3) covering five of the 12 described aphanodactylid species and a total of 15 thoracotreme families. We found Aphanodactylidae to be monophyletic, but widely distant from Pinnotheridae and instead most closely related to Macrophthalmidae (Ocypodoidea) and Varunidae (Grapsoidea). Therefore, the family Aphanodactylidae is corroborated, but its placement in Pinnotheroidea is rejected. Instead, the phylogenetic position of Aphanodactylidae, as clearly distant from other pinnotheroids, demonstrates that obligate commensalism has evolved independently multiple times within Thoracotremata.
Bird-like complex nesting behaviour by the Brazilian-endemic reef fish Gramma brasiliensis
Authors: Leite Jonas R. , Pereira Pedro H. C. , Sanches Eduardo G. , Moura Rodrigo L. , Hostim-Silva Mauricio
Published: February 2018

Nesting is a common behaviour associated with reproduction in several taxa. Nevertheless, this important parental care behaviour is rarely reported for reef-associated fish. The present study provides the first description of bird-like complex nesting behaviour of the endangered basslet (Gramma brasiliensis). Males were observed building nests using macroalgae thalli around holes and depressions, in coralline substrate. Algae were used to camouflage the nest entrance and to form a cushioned bed for egg laying. Nesting is a critical aspect of the reproductive strategy of G. brasiliensis, so, this behaviour is a key factor for the management measures implications on the conservation of the species.
Pathology after
Chlamydia trachomatis
infection is driven by nonprotective immune cells that are distinct from protective populations
Authors: Lijek Rebeccah S. , Helble Jennifer D. , Olive Andrew J. , Seiger Kyra W. , Starnbach Michael N.
Published: February 2018

Significance

Immunopathology after
Chlamydia trachomatis
infection is the major cause of human suffering associated with this pathogen, yet the immune responses that drive pathology are not well defined. We demonstrate that a mucosal influx of neutrophils and CXCR3-driven CD4
+
and CD8
+
T cells is required for
C. trachomatis
pathology and does not contribute to bacterial clearance. Our study decouples immune-mediated pathology from immune-mediated protection for
C. trachomatis
, which will have important translational implications for the development of vaccines and CXCR3-mediated treatments.
Germ-layer commitment and axis formation in sea anemone embryonic cell aggregates
Authors: Kirillova Anastasia , Genikhovich Grigory , Pukhlyakova Ekaterina , Demilly Adrien , Kraus Yulia , Technau Ulrich
Published: February 2018

Significance

Embryonic development of any animal species is a robust series of morphogenetic events tightly controlled by molecular signals. However, the variety of developmental trajectories undertaken by different members of the same phylum suggests that normal development in each particular species might involve only a subset of morphogenetic capacities available to the highly developmentally plastic embryonic cells. Here we show that, faced by a new developmental context, the aggregates of dissociated gastrula cells of the sea anemone
Nematostella vectensis
use an alternative developmental trajectory typical for other, distantly related members of the cnidarian phylum. We conclude that new modes of development may evolve relatively easily due to the versatility and developmental plasticity of embryonic cells.
Reconstructing remote relationships
Authors: Harvey Mark , Mailhammer Robert
Published: February 2018

Evaluation of hypotheses on genetic relationships depends on two factors: database size and criteria on correspondence quality. For hypotheses on remote relationships, databases are often small. Therefore, detailed consideration of criteria on correspondence quality is important. Hypotheses on remote relationships commonly involve greater geographical and temporal ranges. Consequently, we propose that there are two factors which are likely to play a greater role in comparing hypotheses of chance, contact and inheritance for remote relationships: (i) spatial distribution of corresponding forms; and (ii) language specific unpredictability in related paradigms. Concentrated spatial distributions disfavour hypotheses of chance, and discontinuous distributions disfavour contact hypotheses, whereas hypotheses of inheritance may accommodate both. Higher levels of language-specific unpredictability favour remote over recent transmission. We consider a remote relationship hypothesis, the Proto-Australian hypothesis. We take noun class prefixation as a test dataset for evaluating this hypothesis against these two criteria, and we show that inheritance is favoured over chance and contact.
The road to auxiliariness revisited
Authors: Rosemeyer Malte , Grossman Eitan
Published: February 2018

Auxiliary verbs are known to grammaticalize from lexical verbs, but how do lexical verbs acquire verbal complements to begin with? This article provides an account of the semantic and pragmatic basis of grammaticalization of the Spanish anterior (‘perfect’) [acabar +de + infinitive] from a lexical source construction meaningfinish. Based on a description offinishin terms of its qualia structure, we argue that verbs meaningfinishare lexically unsaturated, with an event variable that must be assigned a value, whether implicitly by inference or explicitly by a verbal complement. We show on the basis of historical corpus data from the 13th–18th centuries that overt lexical verb complements are initially motivated by informativity: the infinitive is used to describe the event when the type of event is unexpected. However, this original constructional meaning is eventually lost due to the process ofovertification, which has not been discussed in the literature on language change. Writers started using the infinitive in contexts in which the finished event is not unexpected. The subsequent development of the temporal meaning is motivated by the failure of listeners to accommodate too-costly presuppositions in a particular syntactic context, leading to the reanalysis of the constructional meaning. Consequently, overtification was a necessary condition for the subsequent temporalization of the construction. These findings shed light on possible reasons for the grammaticalization of auxiliary verb constructions, at both early and later stages in their developmental histories.
From middle to passive
Authors: Ahn Mikyung , Yap Foong Ha
Published: February 2018

This paper examines the relationship between middle and passive voice constructions in Korean, in particular how they have come to share the same grammatical marker-eci. Based on diachronic data from the UNICONC (Korean historical) database, spanning Old, Middle and Modern Korean (15th to 20th century), our analysis reveals that-eciwas initially used as a middle voice marker for spontaneous and inchoative events, with change-of-state as their common feature, then extended to transitive contexts, giving rise to passive voice usage. More recently,-ecihas developed into a marker of facilitative middle constructions as well. These semantic extensions involve shifts in aspectual focus from change-of-state to resultative-state, and further to potential aspect and mood. This analysis contributes to our understanding of the diachrony of voice markers beyond the causative-to-passive pathway commonly seen in Northeast Asia to include the middle-to-passive pathway, with typological implications.
But spell checker always corrects witch words eye misspelled
Authors: Riano Adriana , Margolin Sara J.
Published: February 2018

The present study examined spell checker software for both spelling recognition and production among college students. Sixty-four participants identified and corrected spelling in a prewritten story and produced spelling by writing a story. Both were completed with or without spell checker access. Results demonstrated differences between the performance of good and poor spellers (as defined using a baseline spelling test). When compared to good spellers, poor spellers corrected a greater percentage of spelling errors with spell checker than without. Spell checker helped all participants produce fewer spelling errors, but not fewer homophone errors. Additionally, more often than good spellers, poor spellers reported placing less effort into spelling words correctly when using spell checker. These findings suggest that poor spellers may have a greater need for spell checker than good spellers, and may be at a greater risk for relying on the software as the only step in the proofreading process.
How executive control predicts early reading development
Authors: de Sande Eva van , Segers Eliane , Verhoeven Ludo
Published: February 2018

Attentional and action control are two levels of executive control that are essential to early reading development. Together these levels enable the construction and monitoring of cognitive representations and of efficient task-behavior, which are both necessary to benefit from reading instruction. The longitudinal and unique contributions of this internal and external level of executive control to early reading are still unclear. We therefore examined how these control capacities facilitate reading development from kindergarten to second-grade. Attentional and action control and multiple early reading skills were assessed at all three time points. Structural Equation Modeling showed a mediation effect for attentional control and an indirect effect for action control to subsequent reading skills via the contributions to the precursor of phonological awareness. From these results it can be concluded that both types uniquely allowed for the emergence of kindergarten preliteracy skills, which in turn provided children with a better starting point for reading development in first- and second-grade.
Web-Based Alcohol Intervention for Nightclub Patrons: Opposite Effects According to Baseline Alcohol use Disorder Classification
Authors: Sanchez Zila M. , Sanudo Adriana
Published: February 2018

Background: This study aimed to test the effectiveness of a Web-based intervention in preventing alcohol abuse among nightclub patrons. Methods: A probabilistic sample of the patrons of 31 nightclubs in São Paulo, Brazil, was invited to participate in an online screening using the Alcohol Use Disorders Identification Test (AUDIT). A total of 1057 patrons met the inclusion criteria to participate in the randomized controlled trial, with data collection at 0, 3, 6, and 12 months. At baseline, participants were classified into 2 AUDIT score groups: a “high-risk” group (AUDIT ≥8; 44%) and a “low-risk” group (AUDIT <8; 56%). In both groups, the intervention subgroup was exposed once to a personalized normative feedback screen with information on the participant's alcohol consumption and its potential consequences. Results: After 12 months, no differences were found between the intervention and the control conditions in either risk group. In the “high-risk” group, there were significant reductions of both the AUDIT score and the prevalence of binge drinking (BD) over time in both the control and the intervention subgroups. In addition, an effect of the intervention was observed at 6 months, i.e., there was an estimated 13% reduction in the AUDIT score in favor of the intervention subgroup (odds ratio [OR] = 0.87; 95% confidence interval [CI]: 0.76, 1.00). In the “low-risk” group, both the control patrons and those receiving the intervention had increased AUDIT scores. Conclusion: The results suggest that the time effect of participating in the study may have had a beneficial outcome in reducing harmful drinking among patrons in the “high-risk” group. The intervention is not recommended to the “low-risk” group.
Preliminary Investigation of a Videogame Prototype for Cigarette and Marijuana Prevention in Adolescents
Authors: Duncan Lindsay R. , Hieftje Kimberly D. , Pendergrass Tyra M. , Sawyer Benjamin G. , Fiellin Lynn E.
Published: February 2018

Background: Videogames are becoming increasingly popular to deliver health interventions; however, their role in the primary prevention of cigarette and marijuana use has not yet been evaluated. The purpose of this study was to conduct a preliminary test of the efficacy of a role-playing videogame prototype, smokeSCREEN, aimed at developing knowledge and behavioral skills associated with primary prevention of cigarette and marijuana use. The authors also explored participants’ gameplay experience. Methods: This study employed a 1-group pretest-posttest design with 25 adolescent boys and girls aged 11 to 14 years ( Mage = 11.56, SD = 0.77) who had never tried cigarettes or marijuana. Participants played four 1-hour gameplay sessions over a 2-week period. Assessments of knowledge, self-efficacy, attitudes, perceived norms, and intentions related to cigarette and marijuana prevention were collected at baseline and 2-week and 12-week follow-ups. Ratings of gameplay experience were collected after the 2 weeks of gameplay. One-way repeated-measures analyses of variance (ANOVAs) were conducted. Results: Findings are (1) improvements in knowledge for both cigarette (Wilks’ λ = 0.62, F(2, 23) = 7.21, P = .004) and marijuana (Wilks’ λ = 0.67, F(2, 23) = 5.75, P = .009) use from pre- to post-gameplay that were characterized by large effects; and (2) nonsignificant trends in the expected direction emerged for changes in self-efficacy and perceived norms related to both cigarettes and marijuana that were characterized by medium-large effects. Overall, the players provided positive reports of their experience with the smokeSCREEN videogame prototype. Conclusions: These findings provide preliminary evidence that a videogame has the potential to influence key cognitive and motivational variables and can be an engaging means to deliver a cigarette and marijuana prevention intervention.
The peel of Citrus kawachiensis (kawachi bankan) ameliorates microglial activation, tau hyper-phosphorylation, and suppression of neurogenesis in the hippocampus of senescence-accelerated mice
Authors: Okuyama Satoshi , Kotani Yoshimi , Yamamoto Kana , Sawamoto Atsushi , Sugawara Kuniaki , Sudo Masahiko , Ohkubo Yuu , Tamanaha Arisa , Nakajima Mitsunari , Furukawa Yoshiko
Published: February 2018

We previously reported that the dried peel powder of Citrus kawachiensis, one of the citrus products of Ehime, Japan, exerted anti-inflammatory effects in the brain of a lipopolysaccharide-injected systemic inflammation animal model. Inflammation is one of the main mechanisms underlying aging in the brain; therefore, we herein evaluated the anti-inflammatory and other effects of the dried peel powder of C. kawachiensis in the senescence-accelerated mouse-prone 8 (SAMP8) model. The C. kawachiensis treatment inhibited microglial activation in the hippocampus, the hyper-phosphorylation of tau at 231 of threonine in hippocampal neurons, and ameliorated the suppression of neurogenesis in the dentate gyrus of the hippocampus. These results suggest that the dried peel powder of C. kawachiensis exert anti-inflammatory and neuroprotective effects.
Community structure and biovolume size spectra of mesozooplankton in the Pearl River estuary
Authors: Ke Zhixin , Tan Yehui , Huang Liangmin , Liu Jiaxin , Liu Huaxue
Published: February 2018

The Pearl River estuary is the second largest estuary in China. This study reported the species composition and size structure of mesozooplankton in the upper and lower Pearl River estuary in the dry and wet seasons. The normalized biovolume size spectrum of mesozooplankton was constructed to analyze the trophic structure of the community. Copepods were the numerically predominant mesozooplankton group at all sampling stations. However, when converted into biovolume, medusae were dominant in the upper estuary in the dry season and Chaetognatha were dominant in the lower estuary in the wet season. There were apparent seasonal and spatial variations in the normalized biovolume size spectrum characteristics in the Pearl River estuary. In the dry season, the average fitted regression line of the normalized biovolume size spectrum had a slope of −1.02 in the upper estuary and −0.88 in the lower estuary. In the wet season, the average fitted regression line of the normalized biovolume size spectrum had a slope of −0.32 in the lower estuary, and no significant regression of the normalized biovolume size spectrum was found in the upper estuary. It is suggested that the mesozooplankton community was unstable in the upper estuary due to the strong freshwater perturbation in the wet season. The size diversity and normalized biovolume size spectrum slope indicated that the strength of top-down control and trophic efficiency was highest in the lower estuary in the wet season.
Brr6 and Brl1 locate to nuclear pore complex assembly sites to promote their biogenesis
Authors: Zhang Wanlu , Neuner Annett , Rüthnick Diana , Sachsenheimer Timo , Lüchtenborg Christian , Brügger Britta , Schiebel Elmar
Published: February 2018

The paralogous Brr6 and Brl1 are conserved integral membrane proteins of the nuclear envelope (NE) with an unclear role in nuclear pore complex (NPC) biogenesis. Here, we analyzed double-degron mutants of Brr6/Brl1 to understand this function. Depletion of Brr6 and Brl1 caused defects in NPC biogenesis, whereas the already assembled NPCs remained unaffected. This NPC biogenesis defect was not accompanied by a change in lipid composition. However, Brl1 interacted with Ndc1 and Nup188 by immunoprecipitation, and with transmembrane and outer and inner ring NPC components by split yellow fluorescent protein analysis, indicating a direct role in NPC biogenesis. Consistently, we found that Brr6 and Brl1 associated with a subpopulation of NPCs and emerging NPC assembly sites. Moreover, BRL1 overexpression affected NE morphology without a change in lipid composition and completely suppressed the nuclear pore biogenesis defect of nup116Δ and gle2Δ cells. We propose that Brr6 and Brl1 transiently associate with NPC assembly sites where they promote NPC biogenesis.
Voluntary Programs To Encourage Refuges for Pesticide Resistance Management: Lessons from a Quasi‐Experiment
Authors: Brown Zachary S.
Published: February 2018

Economists often treat pesticide resistance as a common‐pool resource problem. While pecuniary economic incentives are the standard prescription for open‐access market failures arising from such resources, non‐pecuniary behavioral approaches (e.g., “nudges”) are also effective in some cases. Yet non‐pecuniary instruments have not previously been evaluated for managing pesticide resistance. I empirically evaluate the performance of such an intervention to manage pest resistance to genetically engineered Bacillus thuringiensis (Bt) corn. The U.S. Environmental Protection Agency permits sale of Bt seed conditional on seed producers compelling customers to plant mandated levels of non‐Bt refuge to delay the evolution of Bt resistance. Because of compliance challenges, the Bt seed producer Monsanto piloted a social marketing program to promote refuge in 17 North Carolina counties in 2013–2014. Using 2013–2016 sales data, I use difference‐in‐differences, fractional regression, discrete changes‐in‐changes, and matched differences econometric models to identify the average treatment effect of the program on refuge planting. Results suggest that if it had covered all corn growers in North Carolina, the intervention would have led the average grower to plant between 2.6% (preferred estimate) and 5.8% more refuge in 2014 compared to the counterfactual. The program increased by at least 12% the average probability of planting any refuge in 2014. I find little evidence that effects of the program persisted in subsequent years after cessation, nor that the program increased compliance with mandated refuge thresholds. Informed by behavioral economics research on other environmental and resource policies, I discuss the implications of these findings for pesticide resistance management.
chromswitch: a flexible method to detect chromatin state switches
Authors: Jessa Selin , Kleinman Claudia L
Published: February 2018

Chromatin state plays a major role in controlling gene expression, and comparative analysis of ChIP-seq data is key to understanding epigenetic regulation. We present chromswitch, an R/Bioconductor package to integrate epigenomic data in a defined window of interest to detect an overall switch in chromatin state. Chromswitch accurately classifies a benchmarking dataset, and when applied genome-wide, the tool successfully detects chromatin changes that result in brain-specific expression.

Availability and implementation

Chromswitch is implemented as an R package available from Bioconductor at https://bioconductor.org/packages/chromswitch. All data and code for reproducing the analysis presented in this paper are available at https://doi.org/10.5281/zenodo.1101260.

Supplementary information

Supplementary data are available at Bioinformatics online.