Slow-light switching in nonlinear Bragg-grating coupler

We study propagation and switching of slow-light pulses in nonlinear couplers with phase-shifted Bragg gratings. We demonstrate that power-controlled nonlinear self-action of light can be used to compensate dispersion-induced broadening of pulses through the formation of gap solitons, to control pulse switching in the coupler, and to tune the propagation velocity.Comment: 3 pages, 4 figure

Twist and shout: a surprising synergy between aryl and N-substituents defines the computed charge transport properties in a series of crystalline diketopyrrolopyrroles

This is the Accepted Manuscript version of an article accepted for publication in CyrstEngComm. Under embargo. Embargo end date: 22 November 2017. Jesus Calvo-Castrp, Sebastian Macza, Connor Thomson, Graeme Morris, Alan R. Kennedy and Callum J. McHugh, ‘Twist and shout: a surprising synergy between aryl and N-substituents defines the computed charge transport properties in a series of crystalline diketopyrrolopyrroles’, CrysEngComm, Vol 18(48): 9382-9390, first published online 22 November 2016, available at doi: 10.1039/C6CE02261HThe influence of systematic variation of aryl and N-substitution on predicted charge transport behaviour in a series of crystalline diketopyrrolopyrroles is evaluated. A correct combination of substituents is revealed to maximise those properties which dictate device performance in organic single crystals based upon this structural motif. For electron transport, furan and N-alkyl substitution emerge as optimal molecular design strategies, whilst phenyl structures bearing N-benzyl substituents are shown to offer the most significant promise as highly sought after crystalline hole transport materials.Peer reviewedFinal Accepted Versio

Single-Particle Green Functions in Exactly Solvable Models of Bose and Fermi Liquids

Based on a class of exactly solvable models of interacting bose and fermi liquids, we compute the single-particle propagators of these systems exactly for all wavelengths and energies and in any number of spatial dimensions. The field operators are expressed in terms of bose fields that correspond to displacements of the condensate in the bose case and displacements of the fermi sea in the fermi case. Unlike some of the previous attempts, the present attempt reduces the answer for the spectral function in any dimension in both fermi and bose systems to quadratures. It is shown that when only the lowest order sea-displacement terms are included, the random phase approximation in its many guises is recovered in the fermi case, and Bogoliubov's theory in the bose case. The momentum distribution is evaluated using two different approaches, exact diagonalisation and the equation of motion approach. The novelty being of course, the exact computation of single-particle properties including short wavelength behaviour.Comment: Latest version to be published in Phys. Rev. B. enlarged to around 40 page

Effect of Body Mass Index on pregnancy outcomes in nulliparous women delivering singleton babies

Peer reviewedPublisher PD

Dissolved noble gases and stable isotopes as tracers of preferential fluid flow along faults in the Lower Rhine Embayment, Germany

Groundwater in shallow unconsolidated sedimentary aquifers close to the Bornheim fault in the Lower Rhine Embayment (LRE), Germany, has relatively low δ2H and δ18O values in comparison to regional modern groundwater recharge, and 4He concentrations up to 1.7 × 10−4 cm3 (STP) g–1 ± 2.2 % which is approximately four orders of magnitude higher than expected due to solubility equilibrium with the atmosphere. Groundwater age dating based on estimated in situ production and terrigenic flux of helium provides a groundwater residence time of ∼107 years. Although fluid exchange between the deep basal aquifer system and the upper aquifer layers is generally impeded by confining clay layers and lignite, this study’s geochemical data suggest, for the first time, that deep circulating fluids penetrate shallow aquifers in the locality of fault zones, implying  that sub-vertical fluid flow occurs along faults in the LRE. However, large hydraulic-head gradients observed across many faults suggest that they act as barriers to lateral groundwater flow. Therefore, the geochemical data reported here also substantiate a conduit-barrier model of fault-zone hydrogeology in unconsolidated sedimentary deposits, as well as corroborating the concept that faults in unconsolidated aquifer systems can act as loci for hydraulic connectivity between deep and shallow aquifers. The implications of fluid flow along faults in sedimentary basins worldwide are far reaching and of particular concern for carbon capture and storage (CCS) programmes, impacts of deep shale gas recovery for shallow groundwater aquifers, and nuclear waste storage sites where fault zones could act as potential leakage pathways for hazardous fluids

A novel role of dendritic gap junction and mechanisms underlying its interaction with thalamocortical conductance in fast spiking inhibitory neurons

<p>Abstract</p> <p>Background</p> <p>Little is known about the roles of dendritic gap junctions (GJs) of inhibitory interneurons in modulating temporal properties of sensory induced responses in sensory cortices. Electrophysiological dual patch-clamp recording and computational simulation methods were used in combination to examine a novel role of GJs in sensory mediated feed-forward inhibitory responses in barrel cortex layer IV and its underlying mechanisms.</p> <p>Results</p> <p>Under physiological conditions, excitatory post-junctional potentials (EPJPs) interact with thalamocortical (TC) inputs within an unprecedented few milliseconds (i.e. over 200 Hz) to enhance the firing probability and synchrony of coupled fast-spiking (FS) cells. Dendritic GJ coupling allows fourfold increase in synchrony and a significant enhancement in spike transmission efficacy in excitatory spiny stellate cells. The model revealed the following novel mechanisms: <b><it>1) </it></b>rapid capacitive current (I_cap) underlies the activation of voltage-gated sodium channels; <b><it>2) </it></b>there was less than 2 milliseconds in which the I_capunderlying TC input and EPJP was coupled effectively; <b><it>3) </it></b>cells with dendritic GJs had larger input conductance and smaller membrane response to weaker inputs; <b><it>4) </it></b>synchrony in inhibitory networks by GJ coupling leads to reduced sporadic lateral inhibition and increased TC transmission efficacy.</p> <p>Conclusion</p> <p>Dendritic GJs of neocortical inhibitory networks can have very powerful effects in modulating the strength and the temporal properties of sensory induced feed-forward inhibitory and excitatory responses at a very high frequency band (>200 Hz). Rapid capacitive currents are identified as main mechanisms underlying interaction between two transient synaptic conductances.</p

Viral-free generation and characterization of a human induced pluripotent stem cell line from dermal fibroblasts

Peripheral dermal fibroblasts (DF) from a healthy 56 year old female were obtained from the Centre for Healthy Brain Ageing (CHeBA) Biobank, University of New South Wales, under the material transfer agreement with the University of Wollongong. DFs were reprogrammed via mRNA-delivered transcription factors into induced pluripotent stem cells (iPSCs). The generated iPSCs were confirmed to be pluripotent, capable of three germ layer differentiation and are thus a useful resource for creating iPSC-derived healthy human cells of any lineage

Carbothermal reduction of mill scales formed on steel billets during continuous casting

AbstractA billet is a bar made from crude steel which surface contains scales which are rich in iron oxides. This study presents the carbothermal reduction of the scales formed in steel billets. The process included the reaction of the iron oxides contents with carbon (in ratio 5:1) and annealing in a tubular furnace under argon atmosphere. The occurred reactions are discussed using thermodynamic calculations and thermal analysis which indicate a three-stage reduction process Fe3O4 ➔ FeO ➔ Fe3C ➔α-Fe with intermediate reactions at the interval temperature 960 and 1300 °C. The X-ray diffraction confirms the reduction to α-Fe with minor presence of unreacted C, magnetite and wustite. Mössbauer spectroscopy analysis was performed at room temperature where a typical sextet corresponding to the dominant α-Fe is shown as well as wustite, magnetite and cementite to a lesser extent. The magnetization measurements confirm the ferromagnetic state corresponding to the α-Fe.</jats:p

The mRNA-based reprogramming of fibroblasts from a SOD1\u3csup\u3eE101G\u3c/sup\u3e familial amyotrophic lateral sclerosis patient to induced pluripotent stem cell line UOWi007

2020 The Authors Dermal fibroblasts were donated by a 43 year old male patient with clinically diagnosed familial amyotrophic lateral sclerosis (ALS), carrying the SOD1E101G mutation. The induced pluripotent stem cell (iPSC) line UOWi007-A was generated using repeated mRNA transfections for pluripotency transcription factors Oct4, Klf4, Sox2, c-Myc, Lin28 and Nanog. The iPSCs carried the SOD1E101G genotype and had a normal karyotype, expressed expected pluripotency markers and were capable of in vitro differentiation into endodermal, mesodermal and ectodermal lineages. This iPSC line may be useful for investigating familial ALS resulting from a SOD1 E101G mutation

Complementary-like Graphene Logic Gates Controlled by Electrostatic Doping

Realization of logic circuits from graphene is very attractive for high-speed nanoelectronics. However, the intrinsic ambipolar nature hinders the formation of graphene logic devices with the conventional complementary architecture. Using electrostatic doping modulation, we show here a facile method to control the charge neutrality points and form a complementary-like structure, in which the ambipolar conduction is used as a benefit rather than a drawback to construct logic devices. A band gap is also introduced in the channels to improve the switching ratio of the graphene transistors. For the first time, complementary-like NOR and NAND logic gates were demonstrated. This method provides a possible route for logic circuits from ambipolar graphene and, in principle, can be also extended to other ambipolar semiconductors, such as organic compounds and carbon nanotube thin films.Comment: 16 pages, 7 figure