Detailed analytical investigation of magnetic field line random walk in turbulent plasmas: I. Two-component slab/two-dimensional turbulence

The random displacement of magnetic field lines in the presence of magnetic turbulence in plasmas is investigated from first principles. A two-component (slab/two-dimensional composite) model for the turbulence spectrum is employes. An analytical investigation of the asymptotic behavior of the field-line mean square displacement (FL-MSD) is carried out. It is shown that the magnetic field lines behave superdifusively for every large values of the position variable z, since the FL-MSD sigma varies as sigma similar to z(4/3). An intermediate diffusive regime may also possible exist for finite values of z under conditions which are explicitly determined in terms of the intrinsic turbulent plasma parameters. The superdiffusie asymptotic result is confirmed numerically via an iterative algorithm. The relevance to previous resuslts is discussed.

Nonlinear excitations in strongly-coupled plasma lattices: envelope solitons, kinks and intrinsic localized modes

Ensembles of charged particles (plasmas) are a highly complex form of matter, most often modeled as a many-body system characterized by weak inter-particle interactions (electrostatic coupling). However, strongly-coupled plasma configurations have recently been produced in laboratory, either by creating ultra-cold plasmas confined in a trap or by manipulating dusty plasmas in discharge experiments. In this paper, the nonlinear aspects involved in the motion of charged dust grains in a one-dimensional plasma monolayer (crystal) are discussed. Different types of collective excitations are reviewed, and characteristics and conditions for their occurrence in dusty plasma crystals are discussed, in a quasi-continuum approximation. Dust crystals are shown to support nonlinear kink-shaped supersonic solitary longitudinal excitations, as well as modulated envelope localized modes associated with longitudinal and transverse vibrations. Furthermore, the possibility for intrinsic localized modes (ILMs) — Discrete Breathers (DBs) — to occur is investigated, from first principles. The effect of mode-coupling is also briefly considered. The relation to previous results on atomic chains, and also to experimental results on strongly-coupled dust layers in gas discharge plasmas, is briefly discussed.

Extracting S-matrix poles for resonances from numerical scattering data: Type-II Pade reconstruction

We present a FORTRAN 77 code for evaluation of resonance pole positions and residues of a numerical scattering matrix element in the complex energy (CE) as well as in the complex angular momentum (CAM) planes. Analytical continuation of the S-matrix element is performed by constructing a type-II Pade approximant from given physical values (Bessis et al. (1994) [421: Vrinceanu et al. (2000) [24]; Sokolovski and Msezane (2004) [23]). The algorithm involves iterative 'preconditioning' of the numerical data by extracting its rapidly oscillating potential phase component. The code has the capability of adding non-analytical noise to the numerical data in order to select 'true' physical poles, investigate their stability and evaluate the accuracy of the reconstruction. It has an option of employing multiple-precision (MPFUN) package (Bailey (1993) [451) developed by D.H. Bailey wherever double precision calculations fail due to a large number of input partial waves (energies) involved. The code has been successfully tested on several models, as well as the F + H-2 -> HE + H, F + HD : HE + D, Cl + HCI CIH + Cl and H + D-2 -> HD + D reactions. Some detailed examples are given in the text.

Analysis of luminescent samples using subtracted shifted Raman spectroscopy

A novel method of obtaining high-quality Raman spectra of luminescent samples was tested using cyclohexane solutions which had been treated with a fluorescent dye. The method involves removing the fixed pattern irregularity found in the spectra taken with CCD detectors by subtracting spectra taken at several different, closely spaced spectrometer positions. It is conceptually similar to SERDS (shifted excitation Raman difference spectroscopy) but has the distinct experimental advantage that it does not require a tunable laser source. The subtracted spectra obtained as the raw data are converted into a more recognisable and conventional form by iterative fitting of appropriate double Lorentzian functions whose peak parameters are then used to 'reconstruct' a conventional representation of the spectrum. Importantly, it is shown that the degree of uncertainty in the resultant 'reconstructed' spectra can be gauged reliably by comparing reconstructed spectra obtained at two different spectrometer shifts (delta and 2 delta), The method was illustrated and validated using a solvent (cyclohexane) the spectrum of which is well known and which contains both regions with complex overlapping bands and regions with isolated bands, Possible sources of error are discussed and it is shown that, provided the degree of uncertainty in the data is correctly characterised, it is completely valid to draw conclusions about the spectra of the sample on the basis of the reconstructed data. The acronym SSRS (subtracted shifted Raman spectroscopy; pronounced scissors) is proposed for this method, to distinguish it from the SERDS technique.

The SEMAINE Database: Annotated Multimodal Records of Emotionally Colored Conversations between a Person and a Limited Agent

SEMAINE has created a large audiovisual database as a part of an iterative approach to building Sensitive Artificial Listener (SAL) agents that can engage a person in a sustained, emotionally colored conversation. Data used to build the agents came from interactions between users and an operator simulating a SAL agent, in different configurations: Solid SAL (designed so that operators displayed an appropriate nonverbal behavior) and Semi-automatic SAL (designed so that users' experience approximated interacting with a machine). We then recorded user interactions with the developed system, Automatic SAL, comparing the most communicatively competent version to versions with reduced nonverbal skills. High quality recording was provided by five high-resolution, high-framerate cameras, and four microphones, recorded synchronously. Recordings total 150 participants, for a total of 959 conversations with individual SAL characters, lasting approximately 5 minutes each. Solid SAL recordings are transcribed and extensively annotated: 6-8 raters per clip traced five affective dimensions and 27 associated categories. Other scenarios are labeled on the same pattern, but less fully. Additional information includes FACS annotation on selected extracts, identification of laughs, nods, and shakes, and measures of user engagement with the automatic system. The material is available through a web-accessible database. © 2010-2012 IEEE.

Synthesis and SAR of a novel positive allosteric modulator (PAM) of the metabotropic glutamate receptor 4 (mGluR4)

This Letter describes the synthesis and SAR of the novel positive allosteric modulator, VU0155041, a compound that has shown in vivo efficacy in rodent models of Parkinson's disease. The synthesis takes advantage of an iterative parallel synthesis approach to rapidly synthesize and evaluate a number of analogs of VU0155041. (C) 2009 Elsevier Ltd. All rights reserved.

Discovery and Development of a Potent and Highly Selective Small Molecule Muscarinic Acetylcholine Receptor Subtype I (mAChR 1 or M-1) Antagonist In Vitro and In Vivo Probe

This article describes the discovery and development of the first highly selective, small molecule antagonist of the muscarinic acetylcholine receptor subtype I (mAChR1 or M-1). An M-1 functional, cell-based, calcium-mobilization assay identified three distinct chemical series with initial selectivity for M-1 versus M-4. An iterative parallel synthesis approach was employed to optimize all three series in parallel, which led to the development of novel microwave-assisted chemistry and provided important take home lessons for probe development projects. Ultimately, this effort produced VU0255035, a potent (IC50 = 130 nM) and selective (>75-fold vs. M-2-M-5 and >10 mu M vs. a panel of 75 GPCRs, ion channels and transporters) small molecule M-1 antagonist. Further profiling demonstrated that VU0255035 was centrally penetrant (Brain(AUC)/Plasma(AUC) of 0.48) and active in vivo, rendering it acceptable as both an in vitro and in vivo MLSCN/MLPCN probe molecule for studying and dissecting M-1 function.

Synthesis and SAR of novel, 4-(phenylsulfamoyl)phenylacetamide mGlu(4) positive allosteric modulators (PAMs) identified by functional high-throughput screening (HTS)

Herein we disclose the synthesis and SAR of a series of 4-(phenylsulfamoyl)phenylacetamide compounds as mGlu(4) positive allosteric modulators (PAMs) that were identified via a functional HTS. An iterative parallel approach to these compounds culminated in the discovery of VU0364439 (11) which represents the most potent (19.8 nM) mGlu(4) PAM reported to date. (C) 2010 Elsevier Ltd. All rights reserved.

Catalysing open innovation through publicly funded R&D: A Comparison of University and Company-based research centres

Public funding of university and company-based R&D centres of excellence is widespread both in core and more peripheral regions. What is less well-known is whether these R&D centres can catalyse multi-directional, multi-actor and iterative innovation. Based on data from a real-time monitoring study, this article explores the development of 18 R&D centres’ external connections. University-based R&D centres establish more new connections than company-based centres and are more likely to be interacting with small or micro-firms. However, there is a general bias towards links with larger firms; micro, small and medium-sized enterprises also are less likely to be involved in collaborative R&D with research centres than other types of relationships. The results suggest the potential for R&D centres to act as a catalyst for open innovation but emphasise the need to ensure that the focus of the R&D being conducted is relevant to the needs of smaller firms.

Re-Stor(y)ing social change

New understandings arise as we encounter the emergent integration of both rational and emotional, physical and spiritual, masculine and feminine through imagination, myth, and storytelling. This expanded space fosters an iterative spiraling process whereby new personal and collective futures emerge from transformative possibilities. Contemplating love and the situatedness of our being creates a space for seeing differently, more inclusively. Thought Woman tells a story of encounters arising from contemplation, framing an emancipatory path toward wholeness and unity, being shaped through becoming, recognizing the interrelated web of life wherein humankind can flourish. Flourishing represents the central focus of the critical accounting project.

Selective hydrogenation of acetylene in ethylene rich feed streams at high pressure over ligand modified Pd/TiO2

The selective hydrogenation of acetylene from ethylene rich streams was conducted at high pressure and in the presence of CO over two 1 wt% loaded Pd/TiO2 catalysts with differing dispersions. Although, the more poorly dispersed sample did not result in high acetylene conversion only a small proportion of the total available ethylene was hydrogenated to ethane. The more highly dispersed sample was able to remove acetylene to a level below the detection limit but this was at the expense of significant proportion (ca. 30%) of the available ethylene. Modification of the catalysts by exposure to triphenyl phosphine or diphenyl sulfide and subsequent reduction at 393 K led to improved performance with increased conversion of acetylene and decreased propensity to hydrogenate ethylene resulting in an overall net gain in ethylene. The higher dispersed sample which had been ligand modified provided the best results overall and in particular for the diphenyl sulfide treated sample which was able to completely eliminate acetylene and still obtain a net gain in ethylene. The differences observed are thought to be due to the creation of appropriate active ensembles of Pd atoms which are able to accommodate acetylene but have limited ability to adsorb ethylene. Sub-surface hydrogen formation was suppressed, but not eliminated, by exposure to modifier.

Joint complex diversity coding and channel coding over space, time and frequency

This study provides a general diversity analysis for joint complex diversity coding (CDC) and channel coding-based space-time-frequency codeing is provided. The mapping designs from channel coding to CDC are crucial for efficient exploitation of the diversity potential. This study provides and proves a sufficient condition of full diversity construction with joint three-dimensional CDC and channel coding, bit-interleaved coded complex diversity coding and symbol-interleaved coded complex diversity coding. Both non-iterative and iterative detections of joint channel code and CDC transmission are investigated. The proposed minimum mean-square error-based iterative soft decoding achieves the performance of the soft sphere decoding with reduced complexity.

On MIMO Radar Subarrayed Transmit Beamforming

Multiple-input-multiple-output (MIMO) radar schemes whereby the transmit array is partitioned into subarrays have recently been proposed in the literature to combine advantages of phased array and MIMO radar technology. In this work, we utilize this architecture to significantly simplify a transmit procedure in which the covariance matrix across the MIMO radar array is optimized to improve the Cramer-Rao bound (CRB) on target parameter estimation. The MIMO effective array for regular subarrayed transmit apertures is studied, and necessary conditions to obtain a filled effective aperture are presented, which is important for maintaining nonambiguous, low sidelobe beampatterns. The performance of the subarrayed transmit approach is evaluated in terms of the CRB on target parameter estimation, and the optimisation of the beamformer applied to the subarrays to minimize the CRB is considered. The subarrayed transmit scheme is found to have a CRB which is suboptimal to the full diversity transmission, as expected, but is solvable in a small fraction of the time using an iterative beamspace algorithm developed here.

Portfolio of Compositions investigating ensemble improvisation, distributed and real-time scoring, and multi-nodal input and output

This output is a collection of compositions which explore issues of ensemble improvisation, ensemble management and orchestration, real-time and distributed scoring, multi-nodal inputs and outputs, and animated and graphic notation. Compositions include: Activities I; tutti, duet, trio, solo, quartet; Lewitt Notations I; Webwork I; and Sometimes I feel the space between people (voices) in terms of tempos. These compositions are presented in computer animated scores which are synchronized through the network and subject to real-time modification and control. They can be performed by ensembles distributed over large physical spaces connected by the network. The scores for these compositions include software which displays the animations to the performers, software to structure and disseminate score events, and triggering software that allows the control of a performance to be distributed. Scores can also include live electronics which are coordinated with graphic events.

Evaluating the impact of network density, hidden nodes and capture effect for throughput guarantee in multi-hop wireless networks

To optimize the performance of wireless networks, one needs to consider the impact of key factors such as interference from hidden nodes, the capture effect, the network density and network conditions (saturated versus non-saturated). In this research, our goal is to quantify the impact of these factors and to propose effective mechanisms and algorithms for throughput guarantees in multi-hop wireless networks. For this purpose, we have developed a model that takes into account all these key factors, based on which an admission control algorithm and an end-to-end available bandwidth estimation algorithm are proposed. Given the necessary network information and traffic demands as inputs, these algorithms are able to provide predictive control via an iterative approach. Evaluations using analytical comparison with simulations as well as existing research show that the proposed model and algorithms are accurate and effective.