A Focus Of Attention Algorithm For Expert Systems

This research is primarily concerned with increasing the performance of expert systems. A refined focus of attention strategy and its affect on performance are discussed. Early expert systems used a brute force approach to process the knowledge base. Each production rule in the knowledge base was evaluated each cycle. More recently, processing efficiency has been increased by focusing the attention of the inference engine on a subset of the rules by filtering for further testing, only rules that could possibly fire given the current content of the context base. Focus of attention as developed in this research increases performance over filtering systems by further narrowing the focus of attention of the inference engine, down to the subexpression level. Positive results are reported

VAST Challenge 2015: Mayhem at Dinofun World

A fictitious amusement park and a larger-than-life hometown football hero provided participants in the VAST Challenge 2015 with an engaging yet complex storyline and setting in which to analyze movement and communication patterns. The datasets for the 2015 challenge were large—averaging nearly 10 million records per day over a three day period—with a simple straightforward structured format. The simplicity of the format belied a complex wealth of features contained in the data that needed to be discovered and understood to solve the tasks and questions that were posed. Two Mini-Challenges and a Grand Challenge compose the 2015 competition. Mini-Challenge 1 contained structured location and date-time data for park visitors, against which participants were to discern groups and their activities. MiniChallenge 2 contained structured communication data consisting of metadata about time-stamped text messages sent between park visitors. The Grand Challenge required participants to use both movement and communication data to hypothesize when a crime was committed and identify the most likely suspects from all the park visitors. The VAST Challenge 2015 received 74 submissions, and the datasets were downloaded, at least partially, from 26 countries

Structural optimization of 3D masonry buildings

In the design of buildings, structural analysis is traditionally performed after the aesthetic design has been determined and has little influence on the overall form. In contrast, this paper presents an approach to guide the form towards a shape that is more structurally sound. Our work is centered on the study of how variations of the geometry might improve structural stability. We define a new measure of structural soundness for masonry buildings as well as cables, and derive its closed-form derivative with respect to the displacement of all the vertices describing the geometry. We start with a gradient descent tool which displaces each vertex along the gradient. We then introduce displacement operators, imposing constraints such as the preservation of orientation or thickness; or setting additional objectives such as volume minimization.Shell Oil CompanyNatural Sciences and Engineering Research Council of Canada (PGS Program)Samsung Scholarship Foundatio

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

VAST Challenge 2016: Streaming Visual Analytics

The 2016 VAST Challenge returns to the (fictional) island of Kronos to pose three Mini-Challenges. In Mini-Challenge 1, participants must design an innovative interactive visual interface that enables security investigators from the Euybia Island Resort and Conference Center to conduct real-time analysis of streaming data. In Mini-Challenge 2, the GAStech Corporation returns from the 2014 kidnapping disaster more committed than ever to tighten up operations at its new headquarters in Abila. Using data from stationary and mobile sensors of multiple types, participants must help the company to understand both operational issues as well as security issues. In Mini-Challenge 3, participants are asked to try their hand at the most complex VAST Challenge scenario to date: 2.5 days of live, streaming operational data. The VAST Challenge 2016 received 29 submissions and had participation from 72 reviewers

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

Boronate probes for the detection of hydrogen peroxide release from human spermatozoa

Human spermatozoa are compromised by production of reactive oxygen species (ROS) and detection of ROS in spermatozoa is important for the diagnosis of male infertility. Probes 2',7'-dichlorohydrofluorescein diacetate (DCFH), dihydroethidium (DHE) and MitoSOX red (MSR) are commonly used for detecting ROS by flow cytometry, however these probes lack sensitivity to hydrogen peroxide (H2O2), which is particularly damaging to mammalian sperm cells. This study reports the synthesis and use of three aryl boronate probes, peroxyfluor-1 (PF1), carboxy peroxyfluor-1 (CPF1) and a novel probe 2(2-ethoxyethoxy)ethoxy peroxyfluor-1 (EEPF1) in human spermatozoa. PF1 and EEPF1 were found to be effective in detecting H2O2 and peroxynitrite (ONOO(-)) produced by spermatozoa when stimulated with menadione or 4-hydroxynonenal. EEPF1 was more effective at detection of ROS in spermatozoa than DCFH, DHE and MSR; furthermore it distinguished poorly motile sperm as shown by greater ROS production. EEPF1 should therefore have a significant role in diagnosis of oxidative stress in male infertility, cryopreservation, age, lifestyle and exposure to environmental toxicants.Malcolm S. Purdey, Haley S. Connaughton, Sara Whiting, Erik P. Schartner, Tanya M. Monro, Jeremy G. Thompson, R. John Aitken, Andrew D. Abel

Overcoming Barriers to Vaccination By Empowering Citizens to Make Deliberate Choices

Copyright © The authors. Overcoming Barriers to Vaccination By Empowering Citizens to Make Deliberate Choices is one of ten in-depth transatlantic reports published by The British Academy exploring COVID-19 vaccine engagement in the UK and the US. For more details, see: https://www.thebritishacademy.ac.uk/news/the-british-academy-publishes-studies-examining-covid-vaccine-engagement-in-uk-and-usa/.British Academy (COVG7210005); Department for Business, Energy and Industrial Strategy.https://www.thebritishacademy.ac.uk/news/the-british-academy-publishes-studies-examining-covid-vaccine-engagement-in-uk-and-usa

A phase II study of dacetuzumab (SGN-40) in patients with relapsed diffuse large B-cell lymphoma (DLBCL) and correlative analyses of patient-specific factors

BACKGROUND: Patients with DLBCL who are ineligible for or have relapsed after aggressive salvage chemotherapy have a poor prognosis. CD40 is expressed on multiple B-cell neoplasms including DLBCL and is a potential target for immunotherapy. Dacetuzumab (SGN-40), a non-blocking, partial agonist, humanized IgG1, anti-CD40 monoclonal antibody, has previously demonstrated anti-lymphoma activity in a phase I study. METHODS: A phase II study was undertaken to evaluate the rate and duration of objective responses and safety of single-agent dacetuzumab in relapsed DLBCL. Forty-six adult patients with relapsed/refractory DLBCL received up to 12 cycles of intravenous dacetuzumab using intrapatient dose-escalation to a target dose of 8 mg/kg/week in an initial 5-week cycle, followed by 4-week cycles of 8 mg/kg/week. Study endpoints included rate and duration of objective responses, safety, survival, pharmacokinetics, immunogenicity, and exploratory correlative studies. RESULTS: Overall response rate was 9% and disease control rate (complete remission + partial remission + stable disease) was 37%. Common non-hematologic adverse events (AEs) included fatigue, headache, chills, fever, and nausea. The most frequent Grade 3–4 non-hematologic AE was deep venous thrombosis (3 patients). Grade 3–4 lymphopenia (41%), neutropenia (13%), or thrombocytopenia (19%) occurred without associated infection or bleeding. Reversible ocular events, including conjunctivitis and ocular hyperemia, occurred in 8 patients (17%). Patient-specific factors, including Fc-gamma-RIIIa polymorphism, did not appear to correlate with antitumor activity. CONCLUSIONS: Single-agent dacetuzumab has modest activity and manageable toxicity in unselected patients with relapsed DLBCL. Combination regimens and robust methods of patient selection may be necessary for further development. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT00435916