Enabling Technologies for Multi-Gigabit Wireless Communications in the E-Band

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An HI absorption distance to the black hole candidate X-ray binary MAXI J1535-571

With the Australian Square Kilometre Array Pathfinder (ASKAP) we monitored the black hole candidate X-ray binary MAXI J1535--571 over seven epochs from 21 September to 2 October 2017. Using ASKAP observations, we studied the HI absorption spectrum from gas clouds along the line-of-sight and thereby constrained the distance to the source. The maximum negative radial velocities measured from the HI absorption spectra for MAXI J1535--571 and an extragalactic source in the same field of view are $-69\pm4$ km s$^{-1}$ and $-89\pm4$ km s$^{-1}$, respectively. This rules out the far kinematic distance ($9.3^{+0.5}_{-0.6}$ kpc), giving a most likely distance of $4.1^{+0.6}_{-0.5}$ kpc, with a strong upper limit of the tangent point at $6.7^{+0.1}_{-0.2}$ kpc. At our preferred distance, the peak unabsorbed luminosity of MAXI J1535--571 was $>78$ per cent of the Eddington luminosity, and shows that the soft-to-hard spectral state transition occurred at the very low luminosity of 1.2 -- 3.4 $\times$ 10$^{-5}$ times the Eddington luminosity. Finally, this study highlights the capabilities of new wide-field radio telescopes to probe Galactic transient outbursts, by allowing us to observe both a target source and a background comparison source in a single telescope pointing.Comment: Revised after favorable referee report from MNRAS Letter

Adaptive Antenna Arrays for Ad-Hoc Millimetre-Wave Wireless Communications

New technologies that employ millimetre-wave frequency bands to achieve high speed wireless links are gaining more attention (Dyadyuk et. al., 2007, 2009b, 2010a; Hirata et. al., 2006; Lockie & Peck, 2009; Kasugi et. al., 2009; Wells, 2009) due to increasing demand for wideband wireless communications. Very wide uncongested spectrum is available in the E—bands (71-76 GHz and 81-86 GHz) recently allocated for wireless communications in USA, Europe, Korea, Russia and Australia. The E-band provides an opportunity for line-of – sight (LOS) links with higher data rates, well suited for fibre replacement and backhaul applications. Future mobile and ad-hoc communications networks will require higher bandwidth and longer range. An ad-hoc or mobile (e.g. inter-aircraft) network that relies on high gain antennas also requires beam scanning. Adaptive antenna arrays have found a wide rage of applications and are becoming essential parts of wireless communications systems (Abbaspour-Tamijani & Sarabandi, 2003; Do-Hong & Russer, 2004; Gross, 2005; Guo, 2004; Krim & Viberg, 1996; Mailloux, 2005, 2007; Rogstad et al., 2003; Singh et al., 2008). While the spectrum available in the millimetre-wave frequency bands enables multi-gigabit-per second data rates, the practically achievable communication range is limited by several factors. These include the higher atmospheric attenuation at these frequencies and limited output power of monolithic microwave integrated circuits (MMIC) (Doan et al., 2004; Dyadyuk et al., 2008a; Kasper et al., 2009; Floyd et al., 2007; Reynolds et. al., 2006; Vamsi et. al., 2005, Zirath et al., 2004) due to physical constraints. Therefore, the performance of the ad-hoc or mobile millimetre-wave networks requires enhancement by using spatial power combining antenna arrays

Monitoring and Modeling of Emissions from Concentrated Animal Feeding Operations: Overview of Methods

Accurate monitors are required to determine ambient concentration levels of contaminants emanating from concentrated animal feeding operations (CAFOs), and accurate models are required to indicate the spatial variability of concentrations over regions affected by CAFOs. A thorough understanding of the spatial and temporal variability of concentration levels could then be associated with locations of healthy individuals or subjects with respiratory ailments to statistically link the presence of CAFOs to the prevalence of ill health effects in local populations. This workgroup report, which was part of the Conference on Environmental Health Impacts of Concentrated Animal Feeding Operations: Anticipating Hazards—Searching for Solutions, describes instrumentation currently available for assessing contaminant concentration levels in the vicinity of CAFOs and reviews plume dispersion models that may be used to estimate concentration levels spatially. Recommendations for further research with respect to ambient air monitoring include accurately determining long-term average concentrations for a region under the influence of CAFO emissions using a combination of instruments based on accuracy, cost, and sampling duration. In addition, development of instruments capable of accurately quantifying adsorbed gases and volatile organic compounds is needed. Further research with respect to plume dispersion models includes identifying and validating the most applicable model for use in predicting downwind concentrations from CAFOs. Additional data are needed to obtain reliable emission rates from CAFOs

Spontaneous Hydrolyses in Sulfobetaine Micelles. Dependence of Micellar Charge Effects Upon Mechanism

Rate constants of spontaneous hydrolyses in zwitterionic micelles of N-hexadecyl-N,N-dimethyl-3-ammonio-propanesulfonate (SB3-16) are compared with those in cationic (n-C16H33NMe3X, X = Cl, Br, OMes; CTAC1, CTABr, CTAOMes) and anionic (n-C12H25OSO3Na, SDS) micelles. Substrates are methyl benzenesulfonate, 2-adamantyl and pinacolyl 4-nitrobenzenesulfonate, 4-bromo- and 4-nitrobenzoyl chloride, phenyl and 4-nitrophenyl chloroformate and bis(4-nitrophenyl) carbonate. Hydrolyses are micellar inhibited, except for the nitro substituted acid chlorides. Reactions with extensive bond-breaking in the transition state (SN1 hydrolyses) are faster in SDS than in cationic and sulfobetaine micelles, but the other hydrolyses, which involve significant bond-making, are slower in SDS. Rate constants are similar in cationic and sulfobetaine micelles. These micellar charge effects are ascribed to interactions of the polar transition states with the asymetrically charged interfacial region which complement effects of the lower polarities of micelles relative to water

A search for fast radio burst-like emission from Fermi gamma-ray bursts

We report the results of the rapid follow-up observations of gamma-ray bursts (GRBs) detected by the Fermi satellite to search for associated fast radio bursts. The observations were conducted with the Australian Square Kilometre Array Pathfinder at frequencies from 1.2-1.4 GHz. A set of 20 bursts, of which four were short GRBs, were followed up with a typical latency of about one minute, for a duration of up to 11 hours after the burst. The data was searched using 4096 dispersion measure trials up to a maximum dispersion measure of 3763 pc cm$^{-3}$, and for pulse widths $w$ over a range of duration from 1.256 to 40.48 ms. No associated pulsed radio emission was observed above $26 {\rm Jy ms} (w/1 {\rm ms})^{-1/2}$ for any of the 20 GRBs.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journa

Shared decision making for prostate cancer screening: the results of a combined analysis of two practice-based randomized controlled trials

Abstract Background Professional societies recommend shared decision making (SDM) for prostate cancer screening, however, most efforts have promoted informed rather than shared decision making. The objective of this study is to 1) examine the effects of a prostate cancer screening intervention to promote SDM and 2) determine whether framing prostate information in the context of other clearly beneficial men’s health services affects decisions. Methods We conducted two separate randomized controlled trials of the same prostate cancer intervention (with or without additional information on more clearly beneficial men’s health services). For each trial, we enrolled a convenience sample of 2 internal medicine practices, and their interested physicians and male patients with no prior history of prostate cancer (for a total of 4 practices, 28 physicians, and 128 men across trials). Within each practice site, we randomized men to either 1) a video-based decision aid and researcher-led coaching session or 2) a highway safety video. Physicians at each site received a 1-hour educational session on prostate cancer and SDM. To assess intervention effects, we measured key components of SDM, intent to be screened, and actual screening. After finding that results did not vary by trial, we combined data across sites, adjusting for the random effects of both practice and physician. Results Compared to an attention control, our prostate cancer screening intervention increased men’s perceptions that screening is a decision (absolute difference +41%; 95% CI 25 to 57%) and men’s knowledge about prostate cancer screening (absolute difference +34%; 95% CI 19% to 50%), but had no effect on men’s self-reported participation in shared decisions or their participation at their preferred level. Overall, the intervention decreased screening intent (absolute difference −34%; 95% CI −50% to −18%) and actual screening rates (absolute difference −22%; 95% CI −38 to −7%) with no difference in effect by frame. Conclusions SDM interventions can increase men’s knowledge, alter their perceptions of prostate cancer screening, and reduce actual screening. However, they may not guarantee an increase in shared decisions. Trial registration #NCT0063018

Language for Specific Purposes and Corpus-based Pedagogy

This chapter describes how corpus-based pedagogies are used for teaching and learning language for specific purposes (LSP). Corpus linguistics (CL) refers to the study of large quantities of authentic language using computer-assisted methods, which form the basis for computer-assisted language learning (CALL) that uses corpora for reference, exploration, and interactive learning. The use of corpora as reference resources to create LSP materials is described. Direct student uses of corpora are illustrated by three approaches to data-driven learning (DDL) where students engage in hands-on explorations of texts. A combination of indirect and direct corpus applications is shown in an illustration of interactive CALL technologies, including an example of an inclusive corpus-based tool for genre-based writing pedagogy. The chapter concludes with potential prospects for future developments in LSP