bluuebunny/crossref_metadata_2025 huggingface dataset:
Mollusca from the Insect Limestone (Bembridge Marls Member: Bouldnor Formation: Solent Group), Palaeogene, Isle of Wight, southern England
Authors: Munt Martin C.
Published: May 2014

Molluscs from the Insect Limestone of the Bembridge Marls Member are described. The gastropodsLymnaea(Galba)longiscata(Brongniart 1810),Planorbarius discus(Edwards 1852),Gyraulus similisFérussac, 1814,Hippeutis headonensisJodot, 1942, Viviparuslentus(Solander 1766) andViviparus angulosus(J. Sowerby 1817) indicate freshwater alkaline conditions. The cerithioid gastropodTarebia acuta(J. Sowerby 1822) probably represent more brackish conditions.Polymesoda(Pseudocyrena)obovata(J. Sowerby 1817) is the only bivalve present. All were potentially washed into the depocentre. Despite a wide outcrop of the Insect Limestone on the Isle of Wight's northwest and northeast coasts, there are no records of molluscs other than from the Gurnard/Thorness Bay area on the northwest coast of the island.
Dragonflies and damselflies (Insecta: Odonata) from the Late Eocene of the Isle of Wight
Authors: Nel André , Fleck Gunther
Published: May 2014

The odonatan fauna of the Late Eocene of the Isle of Wight is revised. The following taxa are revised or described: the gomphaeschnidsOligoaeschna?anglicaCockerell & Andrews, 1916 andAnglogomphaeschna eocenicagen. et sp. nov.; the aeshnids ‘Oplonaeschna’vectensisCockerell & Andrews, 1916,Aeschnophlebia andreasiNelet al., 2005,Oligaeschna wedmannisp. nov., and a ‘Gynacanthinae’ species;Neophya legrandisp. nov., first fossil representative of the Cordulephyidae; three undescribed ‘Corduliidae’;Eomacrodiplax incompletagen. et sp. nov., first fossil representative of the Urothemistidae; the second representative of the Palaeogene family Bolcathoridae; a Thaumatoneuridae Dysagrionini species A; the megapodagrionidOligoargiolestes oligocenumKennedy, 1925; the two hypolestidsAnglohypolestes fasciatagen. et sp. nov. andEohypolestes hooleyigen. et sp. nov.; the coenagrionid ‘Enallagma'oligocenaCockerell & Andrews, 1916, and three other undescribed species;Angloprotoneura emilielacroixigen. et sp. nov., first fossil European representative of the damselfly family Protoneuridae; and the lestidLestesaff.reginaThéobald, 1937. This fauna has strong similarities with the Recent Afrotropical and Indo-Malayan Odonata, suggesting a warm palaeoclimate for the Late Eocene of the Isle of Wight. ‘Megalestes’anglicusCockerell, 1915 is a Zygoptera Lestiformia or Coenagrionomorpha of uncertain affinities.
Cross-feeding and interkingdom communication in dual-species biofilms of Streptococcus mutans and Candida albicans
Authors: Sztajer Helena , Szafranski Szymon P , Tomasch Jürgen , Reck Michael , Nimtz Manfred , Rohde Manfred , Wagner-Döbler Irene
Published: May 2014

Polymicrobial biofilms are of large medical importance, but relatively little is known about the role of interspecies interactions for their physiology and virulence. Here, we studied two human pathogens co-occuring in the oral cavity, the opportunistic fungus Candida albicans and the caries-promoting bacterium Streptococcus mutans. Dual-species biofilms reached higher biomass and cell numbers than mono-species biofilms, and the production of extracellular polymeric substances (EPSs) by S. mutans was strongly suppressed, which was confirmed by scanning electron microscopy, gas chromatography–mass spectrometry and transcriptome analysis. To detect interkingdom communication, C. albicans was co-cultivated with a strain of S. mutans carrying a transcriptional fusion between a green fluorescent protein-encoding gene and the promoter for sigX, the alternative sigma factor of S. mutans, which is induced by quorum sensing signals. Strong induction of sigX was observed in dual-species biofilms, but not in single-species biofilms. Conditioned media from mixed biofilms but not from C. albicans or S. mutans cultivated alone activated sigX in the reporter strain. Deletion of comS encoding the synthesis of the sigX-inducing peptide precursor abolished this activity, whereas deletion of comC encoding the competence-stimulating peptide precursor had no effect. Transcriptome analysis of S. mutans confirmed induction of comS, sigX, bacteriocins and the downstream late competence genes, including fratricins, in dual-species biofilms. We show here for the first time the stimulation of the complete quorum sensing system of S. mutans by a species from another kingdom, namely the fungus C. albicans, resulting in fundamentally changed virulence properties of the caries pathogen.
Leucine incorporation by aerobic anoxygenic phototrophic bacteria in the Delaware estuary
Authors: Stegman Monica R , Cottrell Matthew T , Kirchman David L
Published: May 2014

Aerobic anoxygenic phototrophic (AAP) bacteria are well known to be abundant in estuaries, coastal regions and in the open ocean, but little is known about their activity in any aquatic ecosystem. To explore the activity of AAP bacteria in the Delaware estuary and coastal waters, single-cell 3H-leucine incorporation by these bacteria was examined with a new approach that combines infrared epifluorescence microscopy and microautoradiography. The approach was used on samples from the Delaware coast from August through December and on transects through the Delaware estuary in August and November 2011. The percent of active AAP bacteria was up to twofold higher than the percentage of active cells in the rest of the bacterial community in the estuary. Likewise, the silver grain area around active AAP bacteria in microautoradiography preparations was larger than the area around cells in the rest of the bacterial community, indicating higher rates of leucine consumption by AAP bacteria. The cell size of AAP bacteria was 50% bigger than the size of other bacteria, about the same difference on average as measured for activity. The abundance of AAP bacteria was negatively correlated and their activity positively correlated with light availability in the water column, although light did not affect 3H-leucine incorporation in light–dark experiments. Our results suggest that AAP bacteria are bigger and more active than other bacteria, and likely contribute more to organic carbon fluxes than indicated by their abundance.
Transcription factor IRF5 drives P2X4R+-reactive microglia gating neuropathic pain
Authors: Masuda Takahiro , Iwamoto Shosuke , Yoshinaga Ryohei , Tozaki-Saitoh Hidetoshi , Nishiyama Akira , Mak Tak W. , Tamura Tomohiko , Tsuda Makoto , Inoue Kazuhide
Published: May 2014

In response to neuronal injury or disease, microglia adopt distinct reactive phenotypes via the expression of different sets of genes. Spinal microglia expressing the purinergic P2X4 receptor (P2X4R) after peripheral nerve injury (PNI) are implicated in neuropathic pain. Here we show that interferon regulatory factor-5 (IRF5), which is induced in spinal microglia after PNI, is responsible for direct transcriptional control of P2X4R. Upon stimulation of microglia by fibronectin, IRF5 induced de novo expression of P2X4R by directly binding to the promoter region of the P2rx4 gene. Mice lacking Irf5 did not upregulate spinal P2X4R after PNI, and also exhibited substantial resistance to pain hypersensitivity. Furthermore, we found that expression of IRF5 in microglia is regulated by IRF8. Thus, an IRF8-IRF5 transcriptional axis may contribute to shifting spinal microglia toward a P2X4R-expressing reactive state after PNI. These results may provide a new target for treating neuropathic pain.
Ligand field density functional theory for the prediction of future domestic lighting
Authors: Ramanantoanina Harry , Urland Werner , García-Fuente Amador , Cimpoesu Fanica , Daul Claude
Published: May 2014

A ligand field density functional theory model for two-open-shell f and d electrons.
Recent advances in the analysis of therapeutic proteins by capillary and microchip electrophoresis
Authors: Creamer Jessica S. , Oborny Nathan J. , Lunte Susan M.
Published: May 2014

A review of recent advances and applications of capillary and microchip electrophoresis techniques for biopharmaceutical analysis.
Photoresponsive supramolecular self-assembly of monofunctionalized pillar[5]arene based on stiff stilbene
Authors: Wang Yuan , Xu Jiang-Fei , Chen Yu-Zhe , Niu Li-Ya , Wu Li-Zhu , Tung Chen-Ho , Yang Qing-Zheng
Published: May 2014

We reported a photoresponsive monofunctionalized pillar[5]arene based on stiff stilbene.Z-1tends to form self-complexing [1]pseudorotaxanes and [c2] daisy chains, whereasE-1forms supramolecular polymers.
Dissolvable metallohydrogels for controlled release: evidence of a kinetic supramolecular gel phase intermediate
Authors: Saha Subhadeep , Bachl Jürgen , Kundu Tanay , Díaz Díaz David , Banerjee Rahul
Published: May 2014

Two shape-persistent metallohydrogels were synthesized and found to display unique opaque gel-to-transparent gel phase transition as well as gradual dissolution in water, which offered a versatile platform for drug delivery applications.
Solution-mediated phase transformation of uric acid dihydrate
Authors: Presores Janeth B. , Swift Jennifer A.
Published: May 2014

Various crystalline phases of uric acid are frequently identified components of human kidney stones, including anhydrous uric acid (UA) and uric acid dihydrate (UAD).
Photoluminescent 3D lanthanide MOFs with a rare (10,3)-d net based on a new tripodal organic linker
Authors: Yang Qing-Yuan , Pan Mei , Wei Shi-Chao , Hsu Chien-Wei , Lehn Jean-Marie , Su Cheng-Yong
Published: May 2014

Isomorphous Ln-MOFs with a rare (10,3)-d network were assembled from a dual functional ligand which sensitizes Ln-based luminescence, achieving high quantum yield for Tb-MOF.
Quasi-enantiomeric single-nucleoside and quasi-racemic two-nucleoside hydrochloride salts and ruthenium complexes of cytidine and 2′,3′-dideoxycytidine analogs unveiling the negligible structure-driving role of the 2′,3′-moieties
Authors: Martins Felipe Terra , Corrêa Rodrigo S. , Batista Alzir Azevedo , Ellena Javier
Published: May 2014

The role of differences at the 2′,3′-positions in the crystal structure of cytidine nucleosides.
Optical and electrochemical properties of ethynylaniline derivatives of phenothiazine, phenothiazine-5-oxide and phenothiazine-5,5-dioxide
Authors: Thériault Kim D. , Sutherland Todd C.
Published: May 2014

Modifications in the sulfur oxidation state of phenothiazine results in dramatic changes to the excited-state geometry with little effect on the HOMO energy.
Alkaline O2 reduction on oxide-derived Au: high activity and 4e− selectivity without (100) facets
Authors: Min Xiaoquan , Chen Yihong , Kanan Matthew W.
Published: May 2014

Despite having no detectable (100) facets, oxide-derived Au electrodes have 4e− O2 reduction activity that rivals (100)-rich Au cubes.
Synthesis of carbon black/carbon nitride intercalation compound composite for efficient hydrogen production
Authors: Wu Zhaochun , Gao Honglin , Yan Shicheng , Zou Zhigang
Published: May 2014

The carbon black/carbon nitride intercalation compound composite photocatalyst was synthesized by molten salt heating for efficient solar hydrogen production.
The synthesis and application of novel Ni(ii)N-alkyl dipyridylaldiminato complexes as selective ethylene oligomerisation catalysts
Authors: Swarts Andrew J. , Mapolie Selwyn F.
Published: May 2014

A series of dinuclear Cl-bridged Ni(ii) complexes,1a–1e, ligated byN-alkyl 2,2′-dipyridylamine ligands displayed high activity in ethylene oligomerisation, when activated with alkyl aluminium reagents. Steric and electronic effects as well as activation pathways were found to have a significant impact on catalyst activity and selectivity.
Titanium imido complexes stabilised by bis(iminophosphoranyl)methanide ligands: the influence of N-substituents on solution dynamics and reactivity
Authors: Normand Adrien T. , Massard Alexandre , Richard Philippe , Canovas Coline , Balan Cédric , Picquet Michel , Auffrant Audrey , Le Gendre Pierre
Published: May 2014

The synthesis, structural study and assessment in catalytic hydroamination of Ti imido complexes with bis(iminophosphoranyl)methanide ligands are reported.
A white phosphorescent coordination polymer with Cu2I2 alternating units linked by benzo-18-crown-6
Authors: Wu Fengshou , Tong Hongbo , Li Zaoying , Lei Wang , Liu Li , Wong Wai-Yeung , Wong Wai-Kwok , Zhu Xunjin
Published: May 2014

A 1D polymer of {[K(benzo-18-crown-6)]2(Cu2I4)}n with a Cu2I2 rhombus alternately connected by sandwich-like [K(benzo-18-crown-6)]2 displays direct white light in the solid state.
Inferring sources for mercury to inland lakes using sediment chronologies of polycyclic aromatic hydrocarbons
Authors: Parsons Matthew J. , Long David T. , Giesy John P. , Kannan Kurunthachalam
Published: May 2014

Sediment PAH chronologies and compound ratios from inland lakes suggest the influence of local to sub-regional scale sources for mercury (Hg).
Biodegradation of marine surface floating crude oil in a large-scale field simulated experiment
Authors: Bao Mutai , Sun Peiyan , Yang Xiaofei , Wang Xinping , Wang Lina , Cao Lixin , Li Fujuan
Published: May 2014

Biodegradation of marine surface floating crude oil with hydrocarbon degrading bacteria, rhamnolipid biosurfactants, and nutrients was carried out by a large-scale field simulated experiment in this paper.
Boundary layer chemical vapour synthesis of self-organised ferromagnetically filled radial-carbon-nanotube structures
Authors: Boi Filippo S. , Wilson Rory M. , Mountjoy Gavin , Ibrar Muhammad , Baxendale Mark
Published: May 2014

Boundary layer chemical vapour synthesis is a new technique that exploits random fluctuations in the viscous boundary layer between a laminar flow of pyrolysed metallocene vapour and a rough substrate to yield ferromagnetically filled radial-carbon-nanotube structures departing from a core agglomeration of spherical nanocrystals individually encapsulated by graphitic shells. The fluctuations create the thermodynamic conditions for the formation of the central agglomeration in the vapour which subsequently defines the spherically symmetric diffusion gradient that initiates the radial growth. The radial growth is driven by the supply of vapour feedstock by local diffusion gradients created by endothermic graphitic-carbon formation at the vapour-facing tips of the individual nanotubes and is halted by contact with the isothermal substrate. The radial structures are the dominant product and the reaction conditions are self-sustaining. Ferrocene pyrolysis yields three common components in the nanowire encapsulated by multiwall carbon nanotubes, Fe3C, α-Fe, and γ-Fe. Magnetic tuning in this system can be achieved through the magnetocrystalline and shape anisotropies of the encapsulated nanowire. Here we demonstrate proof that alloying of the encapsulated nanowire is an additional approach to tuning of the magnetic properties of these structures by synthesis of radial-carbon-nanotube structures with γ-FeNi encapsulated nanowires.
TiO2-photocatalytic acceptorless dehydrogenation coupling of primary alkyl alcohols into acetals
Authors: Zhang Hongxia , Zhu Zhenping , Wu Yupeng , Zhao Tianjian , Li Li
Published: May 2014

Primary alkyl alcohols can be directly converted into acetals and H2via TiO2-photocatalytic dehydrogenation coupling at room temperature, with no need for any hydrogen acceptors.
Selective functionalization and loading of biomolecules in crystalline silicon nanotube field-effect-transistors
Authors: Kwon Soonshin , Chen Zack C. Y. , Noh Hyunwoo , Lee Ju Hun , Liu Hang , Cha Jennifer N. , Xiang Jie
Published: May 2014

Crystalline silicon nanotubes exhibit high electrical mobility, while demonstrating loading of biomolecules inside for the first time.
A novel chemosensor with visible light excitability for sensing Zn2+in physiological medium and in HeLa cells
Authors: Datta Barun Kumar , Thiyagarajan Durairaj , Samanta Soham , Ramesh Aiyagari , Das Gopal
Published: May 2014

A highly sensitive, fluorescent, non-cytotoxic turn-on chemosensor with visible light excitability for the detection of intracellular Zn2+ions.
TEMPO-mediated allylic C–H amination with hydrazones
Authors: Zhu Xu , Chiba Shunsuke
Published: May 2014

TEMPO-mediated reactions of alkenyl hydrazones afforded azaheterocycles via sp3 C–H allylic amination. The transformation is featured by a sequence of remote allylic H-radical shift and allylic homolytic substitution with hydrazone radicals.
Visible light initiating systems for photopolymerization: status, development and challenges
Authors: Shao Jianzhong , Huang Yi , Fan Qinguo
Published: May 2014

A review of recent advances in visible light initiating systems using free radical, cationic and hybrid photoinitiators is presented.
Facile synthesis of biodegradable and clickable polymer
Authors: Yang Hongjun , Ge Jun , Huang Wenyan , Xue Xiaoqiang , Chen Jianhai , Jiang Bibiao , Zhang Guangzhao
Published: May 2014

We report a facile approach to synthesize a biodegradable and clickable polymer consisting of ε-caprolactone (CL) and allyl methacrylate (AMA) with phosphazene base as the catalyst via hybrid copolymerization.
Facile fabrication of Chinese lantern-like MnO@N–C: a high-performance anode material for lithium-ion batteries
Authors: Qiu Tian , Wang Juan , Lu Yanluo , Yang Wensheng
Published: May 2014

Chinese lantern-like MnO@N–C is prepared via a facile process, and exhibits excellent electrochemical performance as an anode material for lithium-ion batteries.
Facile synthesis of magnetic nanocomposites of cellulose@ultrasmall iron oxide nanoparticles for water treatment
Authors: Xiong Rui , Wang Yaru , Zhang Xinxing , Lu Canhui
Published: May 2014

We report a facile in situ approach to synthesize magnetic nanocomposites of cellulose@ultrasmall iron oxide nanoparticles by co-precipitation using ionic liquid as co-solvent for cellulose and iron salt.
Degradation of phenol by air and polyoxometalate nanofibers using a continuous mode
Authors: Xu Jian , Yan Siqi , Li Jianxin , Wang Shengtian , Wang Xiaohong , Huo Mingxin , Jiang Zijiang
Published: May 2014

K5PMo10V2O40/PAN nanofibers, synthesized by an electrospinning technique, were used as catalysts in phenol degradation by air under room temperature in a continuous mode. 100% degradation efficiency of phenol and 94.5% TOC removal have been achieved.
A family of polynuclear cobalt complexes upon employment of an indeno-quinoxaline based oxime ligand
Authors: Canaj Angelos B. , Nodaraki Lydia E. , Ślepokura Katarzyna , Siczek Milosz , Tzimopoulos Demetrios I. , Lis Tadeusz , Milios Constantinos J.
Published: May 2014

The employment of an indeno-quinoxaline based oxime ligand in cobalt chemistry afforded a new family of polynuclear cobalt clusters.
A single colorimetric sensor for multiple target ions: the simultaneous detection of Fe2+ and Cu2+ in aqueous media
Authors: Kim Hyun , Na Yu Jeong , Song Eun Joo , Kim Kyung Beom , Bae Jeong Mi , Kim Cheal
Published: May 2014

The receptor 1 provides a novel approach for the simultaneous colorimetric recognition of two metal ions Fe2+ and Cu2+.
Molecular stacking structure and field-effect transistor characteristics of crystalline poly(3-hexylthiophene)-block-syndiotactic polypropylene through solvent selectivity
Authors: Lo Chen-Tsyr , Lin Chih-Jung , Lee Jing-Yu , Tung Shih-Huang , Tsai Jing-Cherng , Chen Wen-Chang
Published: May 2014

The effect of both the solvent selectivity and rod/coil ratio on the molecular packing structures, morphologies and field-effect characteristics of the crystalline–crystalline P3HT-b-sPP diblock copolymers are reported.
Advancement of sorption-based heat transformation by a metal coating of highly-stable, hydrophilic aluminium fumarate MOF
Authors: Jeremias Felix , Fröhlich Dominik , Janiak Christoph , Henninger Stefan K.
Published: May 2014

A 300 μm thick, polycrystalline, thermally well coupled coating of microporous aluminium fumarate was deposited on a metal substrate and found to be stable for at least 4500 ad-/desorption cycles with water vapour.
Which conformations make stable crystal structures? Mapping crystalline molecular geometries to the conformational energy landscape
Authors: Thompson Hugh P. G. , Day Graeme M.
Published: May 2014

Flexible organic molecules often do not adopt their lowest energy conformer in crystal structures. We find that there is a preference for molecules to crystallise with high surface area conformers.
Complete stereodivergence in the synthesis of 2-amino-1,3-diols from allenes
Authors: Adams Christopher S. , Grigg R. David , Schomaker Jennifer M.
Published: May 2014

Herein, we describe studies to understand how both reagent and substrate control can be effectively employed in the stereodivergent oxidative amination of allenes, with transfer of the axial chirality of an enantioenriched precursor to point chirality in each possible diastereomeric 2-amino-1,3-diol product.
Multiferroism in hexagonally stabilized TmFeO3 thin films below 120 K
Authors: Ahn Suk-Jin , Lee Jung-Hoon , Jang Hyun Myung , Jeong Young Kyu
Published: May 2014

The hexagonal TmFeO3 film shows a ferroelectric transition from the paraelectric P63/mmc phase to the P63cm ground state at ∼430 K by c-axis-oriented orbital hybridization between Tm and O ions.
Soluble oxide gate dielectrics prepared using the self-combustion reaction for high-performance thin-film transistors
Authors: Bae Eun Jin , Kang Young Hun , Han Mijeong , Lee Changjin , Cho Song Yun
Published: May 2014

We report the fabrication of high-performance metal oxide thin-film transistors (TFTs) with AlOxgate dielectrics using combustion chemistry in a solution process to provide energy to convert oxide precursors into oxides at low temperatures.
Factors Affecting Sensitivity to Frequency Change in School-Age Children and Adults
Authors: Buss Emily , Taylor Crystal N. , Leibold Lori J.
Published: May 2014

Purpose

The factors affecting frequency discrimination in school-age children are poorly understood. The goal of the present study was to evaluate developmental effects related to memory for pitch and the utilization of temporal fine structure.

Method

Listeners were 5.1- to 13.6-year-olds and adults, all with normal hearing. A subgroup of children had musical training. The task was a 3-alternative forced choice in which listeners identified the interval with the higher frequency tone or the tone characterized by frequency modulation (FM). The standard was 500 or 5000 Hz, and the FM rate was either 2 or 20 Hz.

Results

Thresholds tended to be higher for younger children than for older children and adults for all conditions, although this age effect was smaller for FM detection than for pure-tone frequency discrimination. Neither standard frequency nor modulation rate affected the child/adult difference FM thresholds. Children with musical training performed better than their peers on pure-tone frequency discrimination at 500 Hz.

Conclusions

Testing frequency discrimination using a low-rate FM detection task may minimize effects related to cognitive factors like memory for pitch or training effects. Maturation of frequency discrimination does not appear to differ across conditions in which listeners are hypothesized to rely on temporal cues and place cues.
Effects of Consecutive Wideband Tympanometry Trials on Energy Absorbance Measures of the Middle Ear
Authors: Burdiek Laina M. , Sun Xiao-Ming
Published: May 2014

Purpose

Wideband acoustic immittance (WAI) is a new technique for assessing middle ear transfer function. It includes energy absorbance (EA) measures and can be acquired with the ear canal pressure varied, known as
wideband tympanometry
(WBTymp). The authors of this study aimed to investigate effects of consecutive WBTymp testing on EA.

Method

Data were collected in 29 young adults with normal hearing and middle ear status. Before and after 8 successive WBTymp runs, EA was also measured at ambient pressure. Subsequently, two 226-Hz tympanometry tests were performed.

Results

EA systematically changed over the WBTymp trials in a frequency-specific manner: increase for low frequencies (below 1.5 kHz) and decrease for high frequencies (around 2 kHz and 5 to 6 kHz). The changes, although small, were significant. Much larger EA changes were measured at ambient pressure. The test–retest difference of 226-Hz tympanogram measures was much smaller than previously reported.

Conclusion

Consecutive tympanometry testing alters EA measures of the middle ear. This phenomenon could be mainly attributed to change in stiffness at the eardrum, called
tympanometric preconditioning
. This also has effects on baseline WBTymp outcomes. This effect should be taken into account as a procedural variable in both research and clinical applications of WAI measurements.
Automated Analysis of Child Phonetic Production Using Naturalistic Recordings
Authors: Xu Dongxin , Richards Jeffrey A. , Gilkerson Jill
Published: May 2014

Purpose

Conventional resource-intensive methods for child phonetic development studies are often impractical for sampling and analyzing child vocalizations in sufficient quantity. The purpose of this study was to provide new information on early language development by an automated analysis of child phonetic production using naturalistic recordings. The new approach was evaluated relative to conventional manual transcription methods. Its effectiveness was demonstrated by a case study with 106 children with typical development (TD) ages 8–48 months, 71 children with autism spectrum disorder (ASD) ages 16–48 months, and 49 children with language delay (LD) not related to ASD ages 10–44 months.

Method

A small digital recorder in the chest pocket of clothing captured full-day natural child vocalizations, which were automatically identified into consonant, vowel, nonspeech, and silence, producing the average count per utterance (ACPU) for consonant and vowel.

Results

Clear child utterances were identified with above 72% accuracy. Correlations between machine-estimated and human-transcribed ACPUs were above 0.82. Children with TD produced significantly more consonants and vowels per utterance than did other children. Children with LD produced significantly more consonants but not vowels than did children with ASD.

Conclusion

The authors provide new information on typical and atypical language development in children with TD, ASD, and LD using an automated computational approach.
Predicting Speech Intelligibility With a Multiple Speech Subsystems Approach in Children With Cerebral Palsy
Authors: Lee Jimin , Hustad Katherine C. , Weismer Gary
Published: May 2014

Purpose

Speech acoustic characteristics of children with cerebral palsy (CP) were examined with a multiple speech subsystems approach; speech intelligibility was evaluated using a prediction model in which acoustic measures were selected to represent three speech subsystems.

Method

Nine acoustic variables reflecting different subsystems, and speech intelligibility, were measured in 22 children with CP. These children included 13 with a clinical diagnosis of dysarthria (speech motor impairment [SMI] group) and 9 judged to be free of dysarthria (no SMI [NSMI] group). Data from children with CP were compared to data from age-matched typically developing children.

Results

Multiple acoustic variables reflecting the articulatory subsystem were different in the SMI group, compared to the NSMI and typically developing groups. A significant speech intelligibility prediction model was obtained with all variables entered into the model (adjusted
R
2
= .801). The articulatory subsystem showed the most substantial independent contribution (58%) to speech intelligibility. Incremental
R
2
analyses revealed that any single variable explained less than 9% of speech intelligibility variability.

Conclusions

Children in the SMI group had articulatory subsystem problems as indexed by acoustic measures. As in the adult literature, the articulatory subsystem makes the primary contribution to speech intelligibility variance in dysarthria, with minimal or no contribution from other systems.
Dynamics of tungsten hexacarbonyl, dicobalt octacarbonyl, and their fragments adsorbed on silica surfaces
Authors: Muthukumar Kaliappan , Valentí Roser , Jeschke Harald O.
Published: May 2014

Tungsten and cobalt carbonyls adsorbed on a substrate are typical starting points for the electron beam induced deposition of tungsten or cobalt based metallic nanostructures. We employ first principles molecular dynamics simulations to investigate the dynamics and vibrational spectra of W(CO)6 and W(CO)5 as well as Co2(CO)8 and Co(CO)4 precursor molecules on fully and partially hydroxylated silica surfaces. Such surfaces resemble the initial conditions of electron beam induced growth processes. We find that both W(CO)6 and Co2(CO)8 are stable at room temperature and mobile on a silica surface saturated with hydroxyl groups (OH), moving up to half an Angström per picosecond. In contrast, chemisorbed W(CO)5 or Co(CO)4 ions at room temperature do not change their binding site. These results contribute to gaining fundamental insight into how the molecules behave in the simulated time window of 20 ps and our determined vibrational spectra of all species provide signatures for experimentally distinguishing the form in which precursors cover a substrate.
Covariant formulation of spatially non-symmetric kinetic equilibria in magnetized astrophysical plasmas
Authors: Cremaschini Claudio , Tessarotto Massimo , Stuchlík Zdeněk
Published: May 2014

Astrophysical plasmas in the surrounding of compact objects and subject to intense gravitational and electromagnetic fields are believed to give rise to relativistic regimes. Theoretical and observational evidences suggest that magnetized plasmas of this type are collisionless and can persist for long times (e.g., with respect to a distant observer, coordinate, time), while exhibiting geometrical structures characterized by the absence of well-defined spatial symmetries. In this paper, the problem is posed whether such configurations can correspond to some kind of kinetic equilibrium. The issue is addressed from a theoretical perspective in the framework of a covariant Vlasov statistical description, which relies on the method of invariants. For this purpose, a systematic covariant variational formulation of gyrokinetic theory is developed, which holds without requiring any symmetry condition on the background fields. As a result, an asymptotic representation of the relativistic particle magnetic moment is obtained from its formal exact solution, in terms of a suitably defined invariant series expansion parameter (perturbative representation). On such a basis, it is shown that spatially non-symmetric kinetic equilibria can actually be determined, an example being provided by Gaussian-like distributions. As an application, the physical mechanisms related to the occurrence of a non-vanishing equilibrium fluid 4-flow are investigated.
Reflectionless design of optical elements using impedance-tunable transformation optics
Authors: Cao Jun , Zhang Lifa , Yan Senlin , Sun Xiaohan
Published: May 2014

We report a strategy to remove the reflections resulted from the finite embedded transformation-optical design by proposing a theory of impedance-tunable transformation optics, on which the functions of impedance coefficients can be derived in the original space without changing the refractive index. Based on the approach, two-dimensional reflectionless beam compressors/expanders, bends, shifters, and splitters are designed using the modified anisotropic medium. It is found that the reflections can be removed in magnetic response materials for TE polarization or dielectric response materials for TM polarization. The numerical simulations confirm that various reflectionless optical elements can be realized in the pure transformation optics. The proposed method can be generalized to three-dimensional cases and can be applied to other transformation-optical designs.
Spontaneous cavitation in a Lennard-Jones liquid at negative pressures
Authors: Baidakov V. G. , Bobrov K. S.
Published: May 2014

We report a molecular dynamics (MD) study of homogeneous bubble nucleation in a Lennard-Jones liquid under a negative pressure (cavitation). The rate of bubble nucleation has been determined in the range $2 \times 10^{ - 9} < J^{{\kern 1pt} *} = J\sigma ^4 (m/\varepsilon)^{1/2} < 6 \times 10^{ - 6} $2×10−9<J*=Jσ4(m/ɛ)1/2<6×10−6 by the mean lifetime method at temperatures $T{\kern 1pt} ^* = k_{\rm B} T/\varepsilon = 0.35$T*=kBT/ɛ=0.35, 0.4, 0.5, 0.6, 0.7, 0.8. In molecular dynamics simulation calculations have also been made of the coefficient of bubble size diffusion, the Zeldovich nonequilibrium factor, and the radius of a critical nucleus R*. Different approaches to the determination of the nucleation rate in a stretched liquid have been considered in the framework of classical nucleation theory (CNT). The values of J obtained in MD simulation are by 8–20 orders higher than those predicted by CNT. The work of formation of a critical bubble and the dependence of surface tension γ(R*) at the critical bubble–liquid interface have been determined by data of MD simulation from CNT. The values of γ obtained have been approximated by an extended Tolman formula that takes into account, besides a linear correction, also the quadratic in curvature terms. The Tolman length δ∞ is negative and equals –(0.1–0.2)σ. The coefficient at $1/R_{{\kern 1pt} *}^{{\kern 1pt} 2}$1/R*2 is positive and does not exceed σ2.
Full-dimensional characterization of photoelectron spectra of HOCO− and DOCO− and tunneling facilitated decay of HOCO prepared by anion photodetachment
Authors: Wang Jun , Li Jun , Ma Jianyi , Guo Hua
Published: May 2014

The photodetachment of both the HOCO− and DOCO− anions is investigated using full-dimensional quantum wave packets on new ab initio based global potential energy surfaces for both the neutral and anionic species. The calculated electron affinities and neutral fundamental vibrational frequencies of both isotopomers are in good agreement with available experimental data. The measured photoelectron spectra are also accurately reproduced, further validating the accuracy of the potential energy surfaces. In addition, strong mode specificity is found in the lifetimes of the HOCO vibrational features and the tunneling facilitated predissociation rates to H + CO2 are rationalized using the recently proposed sudden vector projection model.
Possible mechanism of adhesion in a mica supported phospholipid bilayer
Authors: Pertsin Alexander , Grunze Michael
Published: May 2014

Phospholipid bilayers supported on hydrophilic solids like silica and mica play a substantial role in fundamental studies and technological applications of phospholipid membranes. In both cases the molecular mechanism of adhesion between the bilayer and the support is of primary interest. Since the possibilities of experimental methods in this specific area are rather limited, the methods of computer simulation acquire great importance. In this paper we use the grand canonical Monte Carlo technique and an atomistic force field to simulate the behavior of a mica supported phospholipid bilayer in pure water as a function of the distance between the bilayer and the support. The simulation reveals a possible adhesion mechanism, where the adhesion is due to individual lipid molecules that protrude from the bilayer and form widely spaced links with the support. Simultaneously, the bilayer remains separated from the bilayer by a thin water interlayer which maintains the bilayer fluidity.
Core level excitations—A fingerprint of structural and electronic properties of epitaxial silicene
Authors: Friedlein R. , Fleurence A. , Aoyagi K. , de Jong M. P. , Van Bui H. , Wiggers F. B. , Yoshimoto S. , Koitaya T. , Shimizu S. , Noritake H. , Mukai K. , Yoshinobu J. , Yamada-Takamura Y.
Published: May 2014

From the analysis of high-resolution Si 2p photoelectron and near-edge x-ray absorption fine structure (NEXAFS) spectra, we show that core level excitations of epitaxial silicene on ZrB2(0001) thin films are characteristically different from those of sp3-hybridized silicon. In particular, it is revealed that the lower Si 2p binding energies and the low onset in the NEXAFS spectra as well as the occurrence of satellite features in the core level spectra are attributed to the screening by low-energy valence electrons and interband transitions between π bands, respectively. The analysis of observed Si 2p intensities related to chemically distinct Si atoms indicates the presence of at least one previously unidentified component. The presence of this component suggests that the observation of stress-related stripe domains in scanning tunnelling microscopy images is intrinsically linked to the relaxation of Si atoms away from energetically unfavourable positions.
Compact two-electron wave function for bond dissociation and Van der Waals interactions: A natural amplitude assessment
Authors: Giesbertz Klaas J. H. , van Leeuwen Robert
Published: May 2014

Electron correlations in molecules can be divided in short range dynamical correlations, long range Van der Waals type interactions, and near degeneracy static correlations. In this work, we analyze for a one-dimensional model of a two-electron system how these three types of correlations can be incorporated in a simple wave function of restricted functional form consisting of an orbital product multiplied by a single correlation function f (r12) depending on the interelectronic distance r12. Since the three types of correlations mentioned lead to different signatures in terms of the natural orbital (NO) amplitudes in two-electron systems, we make an analysis of the wave function in terms of the NO amplitudes for a model system of a diatomic molecule. In our numerical implementation, we fully optimize the orbitals and the correlation function on a spatial grid without restrictions on their functional form. Due to this particular form of the wave function, we can prove that none of the amplitudes vanishes and moreover that it displays a distinct sign pattern and a series of avoided crossings as a function of the bond distance in agreement with the exact solution. This shows that the wave function ansatz correctly incorporates the long range Van der Waals interactions. We further show that the approximate wave function gives an excellent binding curve and is able to describe static correlations. We show that in order to do this the correlation function f (r12) needs to diverge for large r12 at large internuclear distances while for shorter bond distances it increases as a function of r12 to a maximum value after which it decays exponentially. We further give a physical interpretation of this behavior.
Screening effects in ferroelectric resistive switching of BiFeO3 thin films
Authors: Farokhipoor S. , Noheda B.
Published: May 2014

We investigate ferroelectric resistive switching in BiFeO3 thin films by performing local conductivity measurements. By comparing conduction characteristics at artificially up-polarized domains with those at as-grown down-polarized domains, the change in resistance is attributed to the modification of the electronic barrier height at the interface with the electrodes, upon the reversal of the electrical polarization. We also study the effect of oxygen vacancies on the observed conduction and we propose the existence of a different screening mechanism for up and down polarized domains.
Highly oriented, free-standing, superconducting NbN films growth on chemical vapor deposited graphene
Authors: Saraswat Garima , Gupta Priti , Bhattacharya Arnab , Raychaudhuri Pratap
Published: May 2014

NbN films are grown on chemical vapor deposited graphene using dc magnetron sputtering. The orientation and transition temperature of the deposited films is studied as a function of substrate temperature. A superconducting transition temperature of 14 K is obtained for highly oriented (111) films grown at substrate temperature of 150 °C, which is comparable to epitaxial films grown on MgO and sapphire substrates. These films show a considerably high upper critical field of ∼33 T. In addition, we demonstrate a process for obtaining flexible, free-standing NbN films by delaminating graphene from the substrate using a simple wet etching technique. These free-standing NbN layers can be transferred to any substrate, potentially enabling a range of novel superconducting thin-film applications.
Improvement of the relaxation time and the order parameter of nematic liquid crystal using a hybrid alignment mixture of carbon nanotube and polyimide
Authors: Lee Hyojin , Yang Seungbin , Lee Ji-Hoon , Soo Park Young
Published: May 2014

We examined the electrooptical properties of a nematic liquid crystal (LC) sample whose substrates were coated with a mixture of carbon nanotube (CNT) and polyimide (PI). The relaxation time of the sample coated with 1.5 wt. % CNT mixture was about 35% reduced compared to the pure polyimide sample. The elastic constant and the order parameter of the CNT-mixture sample were increased and the fast relaxation of LC could be approximated to the mean-field theory. We found the CNT-mixed polyimide formed more smooth surface than the pure PI from atomic force microscopy images, indicating the increased order parameter is related to the smooth surface topology of the CNT-polyimide mixture.
Simultaneous investigation of ultrafast structural dynamics and transient electric field by sub-picosecond electron pulses
Authors: Li Run-Ze , Zhu Pengfei , Chen Long , Chen Jie , Cao Jianming , Sheng Zheng-Ming , Zhang Jie
Published: May 2014

The ultrafast structure dynamics and surface transient electric field, which are concurrently induced by laser excited electrons of an aluminum nanofilm, have been investigated simultaneously by the same transmission electron diffraction patterns. These two processes are found to be significantly different and distinguishable by tracing the time dependent changes of electron diffraction and deflection angles, respectively. This study also provides a practical means to evaluate simultaneously the effect of transient electric field during the study of structural dynamics under low pump fluence by transmission ultrafast electron diffraction.
Real time nanoscale structural evaluation of gold structures on Si (100) surface using in-situ transmission electron microscopy
Authors: Rath A. , Juluri R. R. , Satyam P. V.
Published: May 2014

Transport behavior of gold nanostructures on Si(100) substrate during annealing under high vacuum has been investigated using in-situ real time transmission electron microscopy (TEM). A comparative study has been done on the morphological changes due to annealing under different vacuum environments. Au thin films of thickness ∼2.0 nm were deposited on native oxide covered silicon substrate by using thermal evaporation system. In-situ real time TEM measurements at 850 °C showed the isotropic growth of rectangular/square shaped gold-silicon alloy structures. During the growth, it is observed that the alloying occurs in liquid phase followed by transformation into the rectangular shapes. For similar system, ex-situ annealing in low vacuum (10−2 millibars) at 850 °C showed the spherical gold nanostructures with no Au-Si alloy formation. Under low vacuum annealing conditions, the rate of formation of the oxide layer dominates the oxide desorption rate, resulting in the creation of a barrier layer between Au and Si, which restricts the inter diffusion of Au in to Si. This work demonstrates the important role of interfacial oxide layer on the growth of nanoscale Au-Si alloy structures during the initial growth. The time dependent TEM images are presented to offer a direct insight into the fundamental dynamics of the sintering process at the nanoscale.
Energy dissipation by whistler turbulence: Three-dimensional particle-in-cell simulations
Authors: Chang Ouliang , Peter Gary S. , Wang Joseph
Published: May 2014

Three-dimensional particle-in-cell simulations of whistler turbulence are carried out on a collisionless, homogeneous, magnetized plasma model. The simulations use an initial ensemble of relatively long wavelength whistler modes and follow the temporal evolution of the fluctuations as they cascade into a broadband, anisotropic, turbulent spectrum at shorter wavelengths. For relatively small levels of the initial fluctuation energy ϵe, linear collisionless damping provides most of the dissipation of the turbulence. But as ϵe and the total dissipation increase, linear damping becomes less important and, especially at βe ≪ 1, nonlinear processes become stronger. The PDFs and kurtoses of the magnetic field increments in the simulations suggest that intermittency in whistler turbulence generally increases with increasing ϵe and βe. Correlation coefficient calculations imply that the current structure dissipation also increases with increasing ϵe and βe, and that the nonlinear dissipation processes in these simulations are primarily associated with regions of localized current structures.
Non-filamentated ultra-intense and ultra-short pulse fronts in three-dimensional Raman seed amplification
Authors: Lehmann G. , Spatschek K. H.
Published: May 2014

Ultra-intense and ultra-short laser pulses may be generated up to the exawatt-zetawatt regime due to parametric processes in plasmas. The minimization of unwanted plasma processes leads to operational limits which are discussed here with respect to filamentation. Transverse filamentation, which originally was derived for plane waves, is being investigated for seed pulse propagation in the so called π-pulse limit. A three-dimensional (3D) three-wave-interaction model is the basis of the present investigation. To demonstrate the applicability of the three-wave-interaction model, the 1D pulse forms are compared with those obtained from 1D particle in cell and Vlasov simulations. Although wave-breaking may occur, the kinetic simulations show that the leading pumped pulse develops a form similar to that obtained from the three-wave-interaction model. In the main part, 2D and 3D filamentation processes of (localized) pulses are investigated with the three-wave-interaction model. It is shown that the leading pulse front can stay filamentation-free, whereas the rear parts show transverse modulations.
Metamaterial composite bandpass filter with an ultra-broadband rejection bandwidth of up to 240 terahertz
Authors: Strikwerda Andrew C. , Zalkovskij Maksim , Lund Lorenzen Dennis , Krabbe Alexander , Lavrinenko Andrei V. , Uhd Jepsen Peter
Published: May 2014

We present a metamaterial, consisting of a cross structure and a metal mesh filter, that forms a composite with greater functional bandwidth than any terahertz (THz) metamaterial to date. Metamaterials traditionally have a narrow usable bandwidth that is much smaller than common THz sources, such as photoconductive antennas and difference frequency generation. The composite structure shown here expands the usable bandwidth to exceed that of current THz sources. To highlight the applicability of this combination, we demonstrate a series of bandpass filters with only a single pass band, with a central frequency (f0) that is scalable from 0.86–8.51 THz, that highly extinguishes other frequencies up to >240 THz. The performance of these filters is demonstrated in experiment, using both air biased coherent detection and a Fourier transform infrared spectrometer (FTIR), as well as in simulation. We present equations—and discuss their scaling laws—which detail the f0 and full width at half max (Δf) of the pass band, as well as the required geometric dimensions for their fabrication using standard UV photolithography and easily achievable fabrication linewidths. With these equations, the geometric parameters and Δf for a desired frequency can be quickly calculated. Using these bandpass filters as a proof of principle, we believe that this metamaterial composite provides the key for ultra-broadband metamaterial design.