bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure sensitivity in oxide catalysis: First-principles kinetic Monte Carlo simulations for CO oxidation at RuO2(111)
Authors: Wang Tongyu , Reuter Karsten
Published: November 2015

We present a density-functional theory based kinetic Monte Carlo study of CO oxidation at the (111) facet of RuO2. We compare the detailed insight into elementary processes, steady-state surface coverages, and catalytic activity to equivalent published simulation data for the frequently studied RuO2(110) facet. Qualitative differences are identified in virtually every aspect ranging from binding energetics over lateral interactions to the interplay of elementary processes at the different active sites. Nevertheless, particularly at technologically relevant elevated temperatures, near-ambient pressures and near-stoichiometric feeds both facets exhibit almost identical catalytic activity. These findings challenge the traditional definition of structure sensitivity based on macroscopically observable turnover frequencies and prompt scrutiny of the applicability of structure sensitivity classifications developed for metals to oxide catalysis.
Multi-scale lattice Boltzmann and mode-coupling theory calculations of the flow of a glass-forming liquid
Authors: Papenkort S. , Voigtmann Th.
Published: November 2015

We present a hybrid-lattice Boltzmann (LB) algorithm for calculating the flow of glass-forming fluids that are governed by integral constitutive equations with pronounced nonlinear, non-Markovian dependence of the stresses on the flow history. The LB simulation for the macroscopic flow fields is combined with the mode-coupling theory (MCT) of the glass transition as a microscopic theory, in the framework of the integration-through transients formalism. Using the combined LB-MCT algorithm, pressure-driven planar channel flow is studied for a schematic MCT model neglecting spatial correlations in the microscopic dynamics. The cessation dynamics after removal of the driving pressure gradient shows strong signatures of oscillatory flow both in the macroscopic fields and the microscopic correlation functions.
A dual cryogenic ion trap spectrometer for the formation and characterization of solvated ionic clusters
Authors: Marsh Brett M. , Voss Jonathan M. , Garand Etienne
Published: November 2015

A new experimental approach is presented in which two separate cryogenic ion traps are used to reproducibly form weakly bound solvent clusters around electrosprayed ions and messenger-tag them for single-photon infrared photodissociation spectroscopy. This approach thus enables the vibrational characterization of ionic clusters comprised of a solvent network around large and non-volatile ions. We demonstrate the capabilities of the instrument by clustering water, methanol, and acetone around a protonated glycylglycine peptide. For water, cluster sizes with greater than twenty solvent molecules around a single ion are readily formed. We further demonstrate that similar water clusters can be formed around ions having a shielded charge center or those that do not readily form hydrogen bonds. Finally, infrared photodissociation spectra of D2-tagged GlyGlyH+ ⋅ (H2O)1−4 are presented. They display well-resolved spectral features and comparisons with calculations reveal detailed information on the solvation structures of this prototypical peptide.
Effect of bismuth surfactant on InP-based highly strained InAs/InGaAs triangular quantum wells
Authors: Gu Y. , Zhang Y. G. , Chen X. Y. , Xi S. P. , Du B. , Ma Y. J.
Published: November 2015

We report the effect of Bi surfactant on the properties of highly strained InAs/InGaAs triangular quantum wells grown on InP substrates. Reduced surface roughness, improved heterostructure interfaces and enhanced photoluminescence intensity at 2.2 μm are observed by moderate Bi-mediated growth. The nonradiative processes are analysed based on temperature-dependent photoluminescence. It is confirmed that Bi incorporation is insignificant in the samples, whereas excessive Bi flux during the growth results in deteriorated performance. The surfactant effect of Bi is promising to improve InP-based highly strained structures while the excess of Bi flux needs to be avoided.
Enhanced quality factor of Fano resonance in optical metamaterials by manipulating configuration of unit cells
Authors: Moritake Yuto , Kanamori Yoshiaki , Hane Kazuhiro
Published: November 2015

By changing unit cell configurations, we demonstrated enhancement of quality factors (Q-factors) of Fano resonance in optical metamaterials composed of asymmetric double bars. The Q-factors of Fano resonance at wavelengths around 1500 nm were extracted from absorption spectra, and the dependence of the degree of asymmetry was studied. Observed enhancement is qualitatively interpreted by dipole-dipole interactions, and destructive interactions were essential for achieving high Q-factors. These results will be useful for improving performance of potential applications using metamaterial resonators such as light emitting devises and sensors.
Numerical investigation on transient flow of a high head low specific speed pump-turbine in pump mode
Authors: Li Deyou , Gong Ruzhi , Wang Hongjie , Wei Xianzhu , Liu Zhansheng , Qin Daqing
Published: November 2015

Transient process of a pump-turbine, in which the inlet discharge decreases rapidly in pump mode, usually appears due to its frequent switch between pump mode and turbine mode. In order to ensure safe and stable operation, the mechanism of flow characteristics during the transient process was investigated combining numerical and experimental methods. First, steady and unsteady simulations were carried out using the shear-stress transport (SST) k-ω turbulence model under 19 mm guide vane opening. External and internal characteristics under different discharges were presented using numerical simulations based on experimental validation. The results show that the position and area of flow separation as well as appearance of vortices vary with time in the transient process. Finally, the variation of the transient frequency characteristics was obtained through short time Fourier transform. It indicates that main frequencies are blade passing frequency and its harmonic frequencies at the beginning of the transient process, then other complicated frequency components occur as the discharge is reduced, which may come from the vortex motion within the runner.
Communication: Polarizable polymer chain under external electric field in a dilute polymer solution
Authors: Budkov Yu. A. , Kolesnikov A. L. , Kiselev M. G.
Published: November 2015

We study the conformational behavior of polarizable polymer chain under an external homogeneous electric field within the Flory type self-consistent field theory. We consider the influence of electric field on the polymer coil as well as on the polymer globule. We show that when the polymer chain conformation is a coil, application of external electric field leads to its additional swelling. However, when the polymer conformation is a globule, a sufficiently strong field can induce a globule-coil transition. We show that such “field-induced” globule-coil transition at the sufficiently small monomer polarizabilities goes quite smoothly. On the contrary, when the monomer polarizability exceeds a certain threshold value, the globule-coil transition occurs as a dramatic expansion in the regime of first-order phase transition. The developed theoretical model can be applied to predicting polymer globule density change under external electric field in order to provide more efficient processes of polymer functionalization, such as sorption, dyeing, and chemical modification
On syntactic intervention in Chinese denominal verbs
Authors: Cheng Jie
Published: November 2015

The derivation of Chinese denominal verbs has undergone a diachronic shift from freedom in Archaic Chinese to restriction in Post-Archaic Chinese. While denominal verbs in Archaic Chinese can be conveniently accommodated in a pragmatic account, those in Post-Archaic Chinese only yield to a syntactic account. The diachronic shift has arguably resulted from syntactic intervention: only those denominal verbs in Archaic Chinese that can possibly be derived in syntax have survived into Post-Archaic Chinese. In support of this hypothesis is the fact that the prefix *s- andqù shēng bié yì(“falling tone for sense distinction”), responsible for verbalization of nouns in Archaic Chinese, have ceased to operate and given way to zero categories in Post-Archaic Chinese, and the denominal verbs in Post-Archaic Chinese exhibit transparent semantic structures. These findings support the general view about the lexicon-syntax interface that word formation should not be reduced to either the lexicon or syntax alone.
Preaching in uncertain terms
Authors: Malmström Hans
Published: November 2015

This study investigates hedging (standardly assumed to express uncertainty, plausible reasoning and the like) in contemporary sermonic discourse as represented by sermon manuscripts from three Christian denominations in the UK. The article addresses three research questions: (i) To what extent is preaching employed as a discursive resource during preaching; (ii) What form does hedging take in sermonic discourse; and (iii) What are preachers’ rationale for hedging? The results suggest that hedging is indeed of central concern in sermonic discourse with some kind of hedging device being called upon once every 32 seconds. When preachers hedge they rely on standard and transparent linguistic expressions that typically perform this discourse function, and the repertoire includes both ‘conversational’ hedges and hedges that recall practices characteristic of written academic discourse. When preachers self-report on their rationale for hedging a multitude of different discourse functions become apparent. However, it seems that hedging is rarely used to convey lack of epistemic confidence; rather, hedging is seen as a productive interpersonal means to address one of the main objectives of contemporary, turn-to-the-listener, preaching — namely acknowledging sermon listeners as active partners in a sermonic experience.
Effects of high pCO2 on Tanner crab reproduction and early life history—Part I: long-term exposure reduces hatching success and female calcification, and alters embryonic development
Authors: Swiney Katherine M. , Long William Christopher , Foy Robert J.
Published: November 2015

Ocean acidification, a decrease in ocean pH due to absorption of anthropogenic atmospheric CO2, has variable effects on different species. To examine the effects of long-term exposure on Tanner crab (Chionoecetes bairdi) embryonic development, hatching success, and calcification, ovigerous females were reared in one of three treatments: ambient pH (∼8.1), pH 7.8, and pH 7.5 for 2 years. Embryos and larvae in year 1 were from oocytes developed in the field and appear resilient to high pCO2. Embryos and larvae in year 2 were from oocytes developed under high pCO2 conditions. Oocyte development appears sensitive to high pCO2, effects carryover and altered embryonic development, and reduced hatching success with on average 71% fewer viable larvae hatched in the pH 7.5 treatment than in the other treatments. Per cent calcium was reduced among females exposed to pH 7.5 waters, and their carapaces were noticeably more pliable than those in the other treatments. Softer carapaces may result in reduced defences against predators, and a reduction in the ability to feed on prey with hard parts such as shells. The results from this long-term study suggest that projected ocean pH levels within the next two centuries will likely have a pronounced impact on Tanner crab populations unless the crab are able to acclimatize or adapt to changing conditions.
Octodon degus kin and social structure
Authors: Davis Garrett T. , Vásquez Rodrigo A. , Poulin Elie , Oda Esteban , Bazán-León Enrique A. , Ebensperger Luis A. , Hayes Loren D.
Published: November 2015

A growing body of evidence showing that individuals of some social species live in non-kin groups suggests kin selection is not required in all species for sociality to evolve. Here, we investigate 2 populations of Octodon degus , a widespread South American rodent that has been shown to form kin and non-kin groups. We quantified genetic relatedness among individuals in 23 social groups across 2 populations as well as social network parameters (association, strength, and clustering coefficient) in order to determine if these aspects of sociality were driven by kinship. Additionally, we analyzed social network parameters relative to ecological conditions at burrow systems used by groups, to determine if ecological characteristics within each population could explain variation in sociality. We found that genetic relatedness among individuals within social groups was not significantly higher than genetic relatedness among randomly selected individuals in both populations, suggesting that non-kin structure of groups is common in degus. In both populations, we found significant relationships between the habitat characteristics of burrow systems and the social network characteristics of individuals inhabiting those burrow systems. Our results suggest that degu sociality is non-kin based and that degu social networks are influenced by local conditions.

Es creciente la evidencia que apoya la ocurrencia de especies sociales donde los individuos no están emparentados genéticamente, lo que sugiere que la selección de parentesco no es indispensable para la evolución de la sociabilidad. En este estudio se examinaron dos poblaciones de Octodon degus , un roedor sudamericano donde los grupos sociales pueden o no incluir individuos cercanamente emparentados. Se cuantificó el parentesco genético entre individuos en 23 grupos sociales y en redes sociales de dos poblaciones para determinar si estos aspectos de la sociabilidad dependen del grado de parentesco. Además, se examinaron asociaciones entre los parámetros cuantificados de las redes sociales (asociación, fuerza, coeficiente de anidamiento) y las condiciones ecológicas a nivel de los sistemas de madriguera usados por cada grupo. El grado de parentesco genético dentro de los grupos no fue distinto del grado de parentesco entre individuos de la población tomados al azar, lo que apoya que una estructura de grupos no emparentada es la regla en Octodon degus . En ambas poblaciones se registró una asociación entre características ecológicas de los sistemas de madriguera y atributos de las redes sociales de los individuos que usan estas estructuras. Nuestros resultados indican que la sociabilidad en Octodon degus no está basada en relaciones de parentesco y que las redes sociales de estos animales dependen de las condiciones ecológicas.
Functional neurological symptoms
Authors: Carson Alan , Stone Jon
Published: November 2015

Functional neurological symptoms are a common cause of disability and distress in any neurological service. Varying terminology, including hysteria, conversion disorder, dissociative, non-organic, and psychogenic, reflects the shifting nature of medical thinking, over time, regarding these presentations. They also emphasize the importance of a historical understanding when grappling with this area. This chapter traces this history, from Briquet’s monumental treatise on hysteria in 1859 to a randomized controlled trial of non-epileptic seizures in 2010. In the process, familiar figures such as Freud and Janet are encountered and the electrical treatments of Yealland, for hysteria, are re-evaluated. The chapter highlights how the application of functional neuroimaging perhaps raises more questions than it answers, at the current time, but how it has also aided the reawakening of clinical and research interest in this core area of clinical neurology.
Neuromuscular junction disorders
Authors: Kuwabara Satoshi
Published: November 2015

Ten seminal papers on disorders of the neuromuscular junction are described, covering historical aspects, recent advances in immunological, biological, and genetic researches, and future perspectives. Early descriptions of myasthenia gravis (MG) date back to the seventeenth century, and MG acquired its name in the nineteenth century. The first symptomatic treatment with cholinesterase inhibitors was reported in 1934, leading to the development of modern immunological therapies. Following the discovery of anti-MuSK (muscle-specific tyrosine kinase) antibody in 2001, MG is currently classified into three categories: AChR-positive, MuSK-positive, and dual-seronegative. Lambert-Eaton myasthenic syndrome was recognized in 1956, followed by the discovery of antibodies to voltage-gated calcium channels in the pre-synaptic membrane, facilitating diagnosis and improving the understanding of the pathophysiological mechanisms. Since the late twentieth century, many types of congenital myasthenic syndromes with pre-synaptic, synaptic, and post-synaptic defects have been identified, and a classification based on molecular genetics is in evolution.
Neuroimmunology
Authors: Vincent Angela
Published: November 2015

This chapter relates to antibody-mediated disorders throughout the nervous system. Early papers recall how use of bungarotoxin, passive transfer experiments in mice, and clinical response to plasma exchange confirmed the role of acetylcholine receptor antibodies in myasthenia gravis. Cutting edge techniques subsequently discovered other key neuromuscular junctional proteins, including muscle-specific kinase an additional target for antibodies. Later papers report the link between brain inflammation and severe amnesia, paraneoplastic and non-paraneoplastic, and the identification of the first pathogenic antibodies to a central nervous system (CNS) receptor in Rasmussen’s syndrome. The first report of “Morvan’s syndrome” is followed by a single patient with antibodies immunoprecipitating potassium channels who improved remarkably with plasma exchange. Lastly, the patients in the 1920’s encephalitis lethargica epidemic described in detail by von Economo, exhibited many of the features now recognised as caused by antibodies to various CNS receptors and associated membrane proteins.
Is the baryon acoustic oscillation peak a cosmological standard ruler?
Authors: Roukema Boudewijn F. , Buchert Thomas , Fujii Hirokazu , Ostrowski Jan J.
Published: November 2015

In the standard model of cosmology, the Universe is static in comoving coordinates; expansion occurs homogeneously and is represented by a global scale factor. The baryon acoustic oscillation (BAO) peak location is a statistical tracer that represents, in the standard model, a fixed comoving-length standard ruler. Recent gravitational collapse should modify the metric, rendering the effective scale factor, and thus the BAO standard ruler, spatially inhomogeneous. Using the Sloan Digital Sky Survey, we show to high significance (P < 0.001) that the spatial compression of the BAO peak location increases as the spatial paths’ overlap with superclusters increases. Detailed observational and theoretical calibration of this BAO peak location environment dependence will be needed when interpreting the next decade's cosmological surveys.
Exopolysaccharide biosynthetic glycoside hydrolases can be utilized to disrupt and preventPseudomonas aeruginosabiofilms
Authors: Baker Perrin , Hill Preston J. , Snarr Brendan D. , Alnabelseya Noor , Pestrak Mathew J. , Lee Mark J. , Jennings Laura K. , Tam John , Melnyk Roman , Parsek Matthew R. , Sheppard Donald C. , Wozniak Daniel J. , Howell P. Lynne
Published: November 2015

Bacterial biofilms are a significant medical challenge as they are recalcitrant to current therapeutic regimes. A key component of biofilm formation in the opportunistic human pathogenPseudomonas aeruginosais the biosynthesis of the exopolysaccharides Pel and Psl, which are involved in the formation and maintenance of the structural biofilm scaffold and protection against antimicrobials and host defenses. Given that the glycoside hydrolases – PelAhand PslGh– encoded in thepelandpslbiosynthetic operons, respectively, are utilized forin vivoexopolysaccharide processing, we reasoned that these would provide specificity to targetP. aeruginosabiofilms. Evaluating these enzymes as potential therapeutics, we demonstrate that these glycoside hydrolases selectively target and degrade the exopolysaccharide component of the biofilm matrix and that nanomolar concentrations of these enzymes can both prevent biofilm formation as well as rapidly disrupt preexisting biofilmsin vitro. This treatment was effective against clinical and environmentalP. aeruginosaisolates and reduced biofilm biomass by 58–94%. These non-cytotoxic enzymes potentiated antibiotics as the addition of either enzyme to a sub-lethal concentration of colistin reduced viable bacterial counts by 2.5 orders of magnitude. Additionally, PelAhwas able to increase neutrophil killing by ~50%. This work illustrates the feasibility and benefits of using bacterial exopolysaccharide biosynthetic glycoside hydrolases and synthetic biology to develop novel anti-biofilm therapeutics.
Differential dynamics of the mammalian mRNA and protein expression response to misfolding stress
Authors: Cheng Zhe , Teo Guoshou , Krueger Sabrina , Rock Tara , Koh Hiromi W.L. , Choi Hyungwon , Vogel Christine
Published: November 2015

The relative importance of regulation at the mRNA versus protein level is subject to ongoing debate. To address this question in a dynamic system, we mapped the proteomics and transcriptomics changes in mammalian cells responding to stress induced by dithiothreitol over 30 hours. Specifically, we estimated the kinetic parameters for synthesis and degradation of RNA and proteins, and deconvoluted response patterns common and unique to each regulatory level using a new statistical tool. Overall, both regulatory levels were equally important, but differed in their impact on molecule concentrations. Both mRNA and protein changes peaked between two and eight hours, but mRNA expression fold changes were much smaller than those of the proteins. Further, mRNA concentrations were regulated in a transient, spike-like pattern and returned to values close to pre-treatment levels by the end of the experiment. In contrast, protein concentrations switched only once and established a new steady state, consistent with the dominant role of protein regulation during misfolding stress. Finally, we generated hypotheses on specific regulatory modes for example groups of genes.
A quantitative interaction between signal detection in attention and reward/aversion behavior
Authors: Viswanathan V , Kim BW , Sheppard JP , Ying H , Raman K , Lee MJ , Lee S , Mulhern F , Block M , Calder B , Mortensen D , Blood AJ , Breiter HC ,   Phenotype Genotype Project in Addiction and Mood Disorders
Published: November 2015

This study examines how processes such as reward/aversion and attention, which are often studied as independent processes, in fact interact at a systems level. We operationalize attention with a continuous performance task and variables from signal detection theory, and reward/aversion with a keypress task using variables from relative preference theory. We find that while the relationship between reward/aversion and attention is functionally invariant, a power law formulation akin to the Cobb-Douglas production function in economics provides the best model fit and theoretical explanation for the interaction. These results indicate that a decreasing signal-to-noise with signal detection results in higher loss aversion. Furthermore, the estimated exponents for the multiplicative power law suggest capacity constraints to processing for attention and reward/aversion. These results demonstrate a systemic interaction of attention and reward/aversion across subjects, with a quantitative schema raising the hypothesis that mechanistic inference may be possible at the level of behavior alone.
DisGeNET-RDF: harnessing the innovative power of the Semantic Web to explore the genetic basis of diseases
Authors: Queralt Rosinach Núria , Piñero Janet , Bravo Serrano Àlex , Sanz Ferran , Furlong Laura I.
Published: November 2015

Motivation

DisGeNET-RDF makes available knowledge on the genetic basis of human diseases in the Semantic Web (SW). Gene-disease associations (GDAs) and their provenance metadata are published as human-readable and machine-processable web resources. The information on GDAs included in DisGeNET-RDF is interlinked to other biomedical databases to support the development of bioinformatics approaches for translational research through evidence-based exploitation of a rich and fully interconnected Linked Open Data (LOD).

Availability

http://rdf.disgenet.org/

Contact

support@disgenet.org
The limitations ofin vitroexperimentation in understanding biofilms and chronic infection
Authors: Roberts Aled E. L. , Kragh Kasper N. , Bjarnsholt Thomas , Diggle Stephen P.
Published: November 2015

We have become increasingly aware that during infection, pathogenic bacteria often grow in multicellular biofilms which are often highly resistant to antibacterial strategies. In order to understand how biofilms form and contribute to infection,in vitrobiofilm systems such as microtitre plate assays and flow cells, have been heavily used by many research groups around the world. Whilst these methods have greatly increased our understanding of the biology of biofilms, it is becoming increasingly apparent that many of ourin vitromethods do not accurately representin vivoconditions. Here we present a systematic review of the most widely usedin vitrobiofilm systems, and we discuss why they are not always representative of thein vivobiofilms found in chronic infections. We present examples of methods that will help us to bridge the gap betweenin vitroandin vivobiofilm work, so that our bench-side data can ultimately be used to improve bedside treatment.
Interpretation of electron diffraction patterns in the presence of oriented planar faults
Authors: Kurz S. J. B. , Leineweber A. , Mittemeijer E. J.
Published: November 2015

The presence of high planar-fault densities in thin films,e.g.nanotwinned films, leads to peculiar diffraction effects. Frequently, the planar faults are oriented perpendicular to the growth direction. For the case of (nanosized) thin films of face-centered cubic (fcc) metals, often a {111}fccfiber texture prevails with the fiber axis parallel to the film normal. In diffraction patterns of cross-sectional transmission electron microscopy (TEM) samples of such films, as a consequence of twinning with (111) planes parallel to the surface as twinning planes, intensity streaks appear parallel to the growth direction. These intensity streaks are, however, invisible in diffraction patterns of top-view TEM samples. The latter diffraction patterns might be interpreted, at first sight, in terms of the diffraction pattern of a somehow textured fcc polycrystal. However, the diffraction-ring radii deviate from the expected radii. The consideration of intensity cylinders in reciprocal space formed by diffuse intensity streaks generated by the planar faults leads to a perfect match of the accordingly predicted radii with the observed intensity-ring radii.
The equation of state of thePmmnphase of NiSi
Authors: Lord Oliver T. , Thomson Andrew R. , Wann Elizabeth T. H. , Wood Ian G. , Dobson David P. , Vocadlo Lidunka
Published: November 2015

The equation of state of the orthorhombic phase of NiSi withPmmnsymmetry has been determined at room temperature from synchrotron-based X-ray diffraction measurements of its lattice parameters, made in a diamond anvil cell. Measurements were performed up to 44 GPa, using Ne as the pressure medium and Au as the pressure standard. The resulting pressure–volume (P–V) data have been fitted with a Birch–Murnaghan equation of state of third order to yieldV0= 11.650 (7) Å3 atom−1,K0= 162 (3) GPa andK0′ = 4.6 (2). In addition,P–Vdata have been collected on Ni53Si47in the B20 structure using both Ne and He as the pressure media and Cu and Au as the pressure standards, also to 44 GPa. A fit using the same Birch–Murnaghan equation of state of third order yieldsV0= 11.364 (6) Å3 atom−1,K0= 171 (4) GPa andK0′ = 5.5 (3).
The first N-terminal unprotected (Gly-Aib)npeptide: H-Gly-Aib-Gly-Aib-OtBu
Authors: Gessmann Renate , Brückner Hans , Petratos Kyriacos
Published: November 2015

Glycine (Gly) is incorporated in roughly half of all known peptaibiotic (nonribosomally biosynthesized antibiotic peptides of fungal origin) sequences and is the residue with the greatest conformational flexibility. The conformational space of Aib (α-aminoisobutyric acid) is severely restricted by the second methyl group attached to the Cαatom. Most of the crystal structures containing Aib are N-terminal protected. Deprotection of the N- or C-terminus of peptides may alter the hydrogen-bonding scheme and/or the structure and may facilitate crystallization. The structure reported here for glycyl-α-aminoisobutyrylglycyl-α-aminoisobutyric acidtert-butyl ester, C16H30N4O5, describes the first N-terminal-unprotected (Gly-Aib)npeptide. The achiral peptide could form an intramolecular hydrogen bond between the C=O group of Gly1 and the N—H group of Aib4. This hydrogen bond is found in all tetrapeptides and N-terminal-protected tripeptides containing Aib, apart from one exception. In the present work, this hydrogen bond is not observed (N...O = 5.88 Å). Instead, every molecule is hydrogen bonded to six other symmetry-related molecules with a total of eight hydrogen bonds per molecule. The backbone conformation starts in the right-handed helical region (and the left-handed helical region for the inverted molecule) and reverses the screw sense in the last two residues.
Crystal structure of (tert-butylcarbamoyl)(4-chloro-2-oxo-2H-chromen-3-yl)methyl acetate
Authors: Moriguchi Tetsuji , Jalli Venkataprasad , Krishnamurthy Suvratha , Tsuge Akihiko , Yoja Kenji
Published: November 2015

In the title compound, C17H18ClNO5, which was synthesized by reacting 4-chloro-3-formylcoumarin, acetic acid andtert-butyl isocyanide, the acetamido side chain is convoluted with ring-to-side chain C—C—C—C, C—C—C—N and C—C—N—C torsion angles of −123.30 (14), −135.73 (12) and 176.10 (12)°, respectively. In the crystal, N—H...O and weak C—H...O hydrogen bonds are present, which together with π–π coumarin-ring interactions [ring centroid separations = 3.4582 (8) and 3.6421 (9) Å], give rise to a layered structure lying parallel to (001).
Crystal structures of tris[1-oxopyridine-2-olato(1−)]silicon(IV) chloride chloroform-d1disolvate, tris[1-oxopyridine-2-olato(1−)]silicon(IV) chloride acetonitrile unquantified solvate, andfac-tris[1-oxopyridine-2-thiolato(1−)]silicon(IV) chloride chloroform-d1disolvate
Authors: Kraft Bradley M. , Brennessel William W. , Ryan Amy E. , Benjamin Candace K.
Published: November 2015

The cations in the title salts, [Si(OPO)3]Cl·2CDCl3, (I), [Si(OPO)3]Cl·xCH3CN, (II), andfac-[Si(OPTO)3]Cl·2CDCl3, (III) (OPO = 1-oxo-2-pyridinone, C5H4NO2, and OPTO = 1-oxo-2-pyridinethione, C5H4NOS), have distorted octahedral coordination spheres. The first two structures contain the same cation and anion, but different solvents of crystallization led to different solvates and packing arrangements. In structures (I) and (III), the silicon complex cations and chloride anions are well separated, while in (II), there are two C—H...Cl distances that fall just within the sum of the van der Waals radii of the C and Cl atoms. The pyridine portions of the OPO ligands in (I) and (II) are modeled as disordered with the planar flips of themselves [(I): 0.574 (15):0.426 (15), 0.696 (15):0.304 (15), and 0.621 (15):0.379 (15); (II): 0.555 (13):0.445 (13), 0.604 (14):0.396 (14) and 0.611 (13):0.389 (13)], demonstrating that bothfacandmerisomers are co-crystallized. In (II), highly disordered solvent, located in two independent channels along [100], was unable to be modeled. Reflection contributions from this solvent were fixed and added to the calculated structure factors using the SQUEEZE [Spek (2015).Acta Cryst.C71, 9–18] function of programPLATON, which determined there to be 54 electrons in 225 Å3accounted for per unit cell (25 electrons in 109 Å3in one channel, and 29 electrons in 115 Å3in the other). In (I) and (II), all species lie on general positions. In (III), all species are located along crystallographic threefold axes.
Crystal structure of 4-{[(2,4-dihydroxybenzylidene)amino]methyl}cyclohexanecarboxylic acid
Authors: Danish Muhammad , Akbar Saba , Tahir Muhammad Nawaz , Butt Rabia Ayub , Ashfaq Muhammad
Published: November 2015

In the title compound, C15H19NO4, the cyclohexyl ring adopts a chair conformation with both exocyclic C—C bonds in equatorial orientations. The dihedral angle between the basal plane of cyclohexyl ring and the 2,4-dihydroxybenzaldehyde moiety is 84.13 (13)°. An intramolecular O—H...N hydrogen bonds closes anS(6) ring. In the crystal, Oc—H...Op(c = carboxylic acid, p = phenol) hydrogen bonds link the molecules into [100]C(13) chains whereas an Op—H...Ochydrogen bond generates [101]C(15) chains. Together, these bonds generate (010) sheets incorporatingR22(20) loops. Weak C—H...O and C—H...π interactions also occur.
The experiences of mothers caring for a child with developmental disabilities: a cross cultural perspective
Authors: Heer Kuljit , Rose John , Larkin Michael , Singhal Nidhi
Published: November 2015

Purpose

– India has one of the more progressive disability frameworks in the developing world which tends to adopt western philosophies and principles (e.g. parent participation and advocacy) which to some degree mirrors the type of service delivery in the UK. The purpose of this paper is to adopt a cross-cultural perspective to explore caregiving amongst parents caring for a child with intellectual/developmental disabilities in India.

Design/methodology/approach

– Three focus groups were used to interview parents at Action for Autism (AFA) located in Delhi, India. The focus groups explored how disability is encountered within an Indian context.

Findings

– Two main themes were identified in the parents narratives which were “making the decision to get help” and “seeing disabilities in from a new perspective”. Family members played an important role in the decision to get help and acted as a platform for mothers to explore their own concerns. Seeing disability from a new perspective was a four stage process which included initially accepting the diagnosis and their child; regaining control through parenting skills training; witnessing positive changes in their children and themselves and reaping personal benefits as a result of their involvement with AFA.

Research limitations/implications

– The research is very small scale and focused on parents in a specific organisation, as a consequence the results cannot be generalised.

Originality/value

– The discourses of these individuals do provide a useful insight into the provision of services to children in India and provide a starting point for cross-cultural understanding of parenting children with disabilities.
Multi-modular design optimization and multidisciplinary design optimization
Authors: Adami Amirhossein , Mortazavi Mahda , Nosratollahi Mehran
Published: November 2015

Purpose

– For complex engineering problems, multidisciplinary design optimization (MDO) techniques use some disciplines that need to be run several times in different modules. In addition, mathematical modeling of a discipline can be improved for each module. The purpose of this paper is to show that multi-modular design optimization (MMO) improves the design performances in comparison with MDO technique for complex systems.

Design/methodology/approach

– MDO framework and MMO framework are developed to optimum design of a complex system. The nonlinear equality and inequality constrains are considered. The system optimizers included Genetic Algorithm and Sequential Quadratic Programming.

Findings

– As shown, fewer design variables (optimization variables) are needed at the system level for MMO. Unshared variables are optimized in the related module when shared variables are optimized at the system level. The results of this research show that MMO has lower elapsed times (14 percent) with lower F-count (16 percent).

Practical implications

– The monopropellant propulsion upper-stage is selected as a case study. In this paper, the efficient model of the monopropellant propulsion system is proposed. According to the results, the proposed model has acceptable accuracy in mass model (error
<
2 percent), performance estimation (error
<
6 percent) and geometry estimation (error
<
10 percent).

Originality/value

– The monopropellant propulsion system is broken down into the three important modules including propellant tank (tank and propellant), pressurized feeding (tank and gas) and thruster (catalyst, nozzle and catalysts bed) when chemical decomposition, aerothermodynamics, mass and configuration, catalyst and structure have been considered as the disciplines. The both MMO and MDO frameworks are developed for the monopropellant propulsion system.
Employing nonlinear observer for formation control of AUVs under communication constraints
Authors: Das Bikramaditya , Subudhi Bidyadhar , Pati Bibhuti Bhusan
Published: November 2015

Purpose

– The purpose of this paper is to propose development of a formation control algorithm by employing a nonlinear observer for compensating the delay in the sensor signal transmission to the controller arising due to packet dropout in acoustic medium.

Design/methodology/approach

– A robust control law is developed using the sliding mode approach integrated with a communication consensus algorithm for achieving cooperative motion of acoustic underwater vehicles in a group ensuring the transfer of information among the AUVs. In acoustic medium, inter-vehicle communication is challenging for a group of AUVs deployed in formation because underwater channel encounter a number of constraints such as low data rate, packet delays and dropouts.

Findings

– It is observed that the sliding mode control-unscented Kalman filter formation control exhibits superior control performance such as mitigating larger initial error of estimation and removing the use of the Jacobian matrices among the three controllers developed. The proposed nonlinear observer estimates the un-measureable states such as position in x, y and z-axes, heading, rudder and sturn angle, needed for generating the formation control. A simulation setup is realized to demonstrate the performance of the proposed observer-based formation controller. Simulations were performed in MATLAB and the obtained results are analysed and compared which envisage that the proposed control algorithm provides efficient formation control under the acoustic communication constraints.

Originality/value

– Development of observer for achieving formation control of AUVs in underwater area – common reference velocity and error signals being available to all cooperating AUVs – UKO performs better based on initial error estimation and tracking the same path in shallow water area.
A propeller model for general forward flight conditions
Authors: Khan Waqas , Nahon Meyer
Published: November 2015

Purpose

– The purpose of this paper is to develop a physics-based model for UAV propellers that is capable of predicting all aerodynamic forces and moments in any general forward flight condition such as no flow, pure axial flow and pure side flow etc.

Design/methodology/approach

– The methodology adopted in this paper is the widely used Blade Element Momentum Theory (BEMT) for propeller model development. The difficulty arising from the variation of induced flow with blade’s angular position is overcome by supplementing the BEMT with the inflow model developed by Pitt and Peters. More so, high angle of attack aerodynamics is embedded in the simulation as it is likely for the blades to stall in general forward flight, for example during extreme aerobatics/maneuvers.

Findings

– The validity of the model is demonstrated via comparison with experiments as well as with other existing models. It is found that one of the secondary forces is negligible while the other is one order of magnitude less than the primary static thrust, and as such may be neglected depending on the level of accuracy required. On the other hand, both secondary moments must be considered as they are of similar order of magnitude as the primary static torque.

Research limitations/implications

– The paper does not consider the swirl component of the induced flow under the assumption that it is negligible compared to the axial component.

Originality/value

– This paper fulfills the identified need of a propeller model for general forward flight conditions, and aims to fill this void in the existing literature pertaining to UAVs.
“Through the looking glass: envisioning new library technologies” telling stories with technology
Authors: Fernandez Peter
Published: November 2015

Purpose

– This column aims to explore the technologies that are enabling libraries, and the communities they serve, to easily tell their own stories.

Design/methodology/approach

– Point of view.

Findings

– Libraries can facilitate the acquisition of technology and literacies necessary to make recording, sharing and preserving stories of all kinds easy for library patrons.

Practical implications

– Libraries collect, preserve and help distribute information to serve their communities.

Originality/value

– By facilitating access to these emerging mediums, libraries can both empower their communities and play an active role in preserving their communities’ histories.
The effects of institutions and subsidiary competence on the international market orientation in foreign-owned subsidiaries
Authors: Dahms Sven
Published: November 2015

Purpose

– The purpose of this paper is to enhance our understanding on the effects of national and subnational institutions as well as subsidiary competences on the international market orientation in foreign-owned subsidiaries.

Design/methodology/approach

– A postal survey has been conducted based on a census-like database of foreign-owned subsidiaries in the Northwest of England.

Findings

– The findings show a positive relationship on the international market orientation for subsidiaries with extended competences and strong links to local suppliers, universities and competitors. A negative association has been found concerning formal institutional distance and strong links to local customers and government institutions.

Research limitations/implications

– The survey is limited to foreign-owned subsidiaries in the Northwest of England.

Practical implications

– This study implies that subsidiary managers need to take national and subnational institutions as well as subsidiary specific competences into consideration when looking for international market expansion.

Originality/value

– The originality of this paper lies in the detailed investigation of institutions at the national and subnational level as well as subsidiary competences on the international market orientation in foreign-owned subsidiaries.
The case of the unhappy teachers
Authors: Santiago Andrea , Roxas Fernando
Published: November 2015

Synopsis

This case presents the staffing problem of Manuel Garcia, president of Saint Catherine School (SCS). He needed to incentivize quality teachers to stay with the school but he faced three challenges. First, the school is located in a far flung city in Mindanao, Philippines. Second, the city is economically depressed and the parents are price-sensitive. Third, the school is dependent on tuition revenue and collections barely cover school expenditures. Manuel would have to find creative solutions and defend his decision to the teachers and the Board of Trustees.

Research methodology

The researchers relied on primary data to write the case although the Chairman opted that the school name and all the characters names be disguised. The researchers interviewed individually the Chairman of the Board, President, Vice Chancellor for Academics, University Registrar, Finance Director, and Human Resource Manager of the school. The researchers also interviewed faculty members as a group. The information on the exhibits were culled from reports presented by the administrative team.

Relevant courses and levels

The short case is a learning tool for students taking a degree in educational leadership and management. It can be used as part of an integrating module for graduate students. By this time, students would have had prior lessons in financial, trend, and ratio analysis. The case can also be used to reinforce lessons in the following courses at the undergraduate or graduate level: human resource management, data-driven decision making, financial resource management, educational policy, and even communication. Further, the case is suited for school administrators attending executive development programs. Running a school is more than managing the curriculum. There is a business side that has to be considered. This case helps teachers-turned-administrators consider the financial implications of human resource management decisions. In this instance, salaries and benefits.
Resolving large‐scale pressures on species and ecosystems: propensity modelling identifies agricultural effects on streams
Authors: Pearson Caitlin E. , Ormerod Steve J. , Symondson William O.C. , Vaughan Ian P.
Published: November 2015

Although agriculture is amongst the world's most widespread land uses, studies of its effects on stream ecosystems are often limited in spatial extent. National monitoring data could extend spatial coverage and increase statistical power, but present analytical challenges where covarying environmental variables confound relationships of interest.

Propensity modelling is used widely outside ecology to control for confounding variables in observational data. Here, monitoring data from over 3000 English and Welsh river reaches are used to assess the effects of intensive agricultural land cover (arable and pastoral) on stream habitat, water chemistry and invertebrates, using propensity scores to control for potential confounding factors (e.g. climate, geology). Propensity scoring effectively reduced the collinearity between land cover and potential confounding variables, reducing the potential for covariate bias in estimated treatment–response relationships compared to conventional multiple regression.

Macroinvertebrate richness was significantly greater at sites with a higher proportion of improved pasture in their catchment or riparian zone, with these effects probably mediated by increased algal production from mild nutrient enrichment. In contrast, macroinvertebrate richness did not change with arable land cover, although sensitive species representation was lower under higher proportions of arable land cover, probably due to greatly elevated nutrient concentrations.

Synthesis and applications. Propensity modelling has great potential to address questions about pressures on ecosystems and organisms at the large spatial extents relevant to land‐use policy, where experimental approaches are not feasible and broad environmental changes often covary. Applied to the effects of agricultural land cover on stream systems, this approach identified reduced nutrient loading from arable farms as a priority for land management. On this specific issue, our data and analysis support the use of riparian or catchment‐scale measures to reduce nutrient delivery to sensitive water bodies.