Electrical tree structures generated by the ab-initio discharge-avalanche model

Initially the discharge-avalanche model for electrical tree formation treated the local Poisson fields as being derived from the applied Laplace field via a modification factor that was regarded as a random variable in time and space. Recently we have removed this approximation by calculating the local Poisson fields from the space charge arrangement produced by discharges in the tree tubules and avalanches in the surrounding polymer. This “ab-initio” version of the model has now been fully implemented. The ac-cycle is divided into 16 time segments. In each time segment tube-discharges are allowed to occur if the potential difference along a tube is greater than an onset threshold. Positive space charge is regarded as being deposited on the tube walls in the form of positive ions. Negative charge is allowed to penetrate the polymer where it can be used to initiate avalanches and thereby generate damage. The avalanches compete with a field dependant mobility in rearranging the charge around the tree tips

Using deep learning to understand and mitigate the qubit noise environment

Understanding the spectrum of noise acting on a qubit can yield valuable information about its environment, and crucially underpins the optimization of dynamical decoupling protocols that can mitigate such noise. However, extracting accurate noise spectra from typical time-dynamics measurements on qubits is intractable using standard methods. Here, we propose to address this challenge using deep learning algorithms, leveraging the remarkable progress made in the field of image recognition, natural language processing, and more recently, structured data. We demonstrate a neural network based methodology that allows for extraction of the noise spectrum associated with any qubit surrounded by an arbitrary bath, with significantly greater accuracy than the current methods of choice. The technique requires only a two-pulse echo decay curve as input data and can further be extended either for constructing customized optimal dynamical decoupling protocols or for obtaining critical qubit attributes such as its proximity to the sample surface. Our results can be applied to a wide range of qubit platforms, and provide a framework for improving qubit performance with applications not only in quantum computing and nanoscale sensing but also in material characterization techniques such as magnetic resonance.Comment: Accepted for publication, 15 pages, 10 figure

Carbon-accounting methods and reforestation incentives

The emission of greenhouse gases, particularly carbon dioxide, and the consequent potential for climate change are the focus of increasing international concern. Temporary land-use change and forestry projects (LUCF) can be implemented to offset permanent emissions of carbon dioxide from the energy sector. Several approaches to accounting for carbon sequestration in LUCF projects have been proposed. In the present paper, the economic implications of adopting four of these approaches are evaluated in a normative context. The analysis is based on simulation of Australian farm–forestry systems. Results are interpreted from the standpoint of both investors and landholders. The role of baselines and transaction costs are discussed.Resource /Energy Economics and Policy,

X-ray Supercavities in the Hydra A Cluster and the Outburst History of the Central Galaxy's Active Nucleus

A 227 ksec Chandra Observatory X-ray image of the hot plasma in the Hydra A cluster has revealed an extensive cavity system. The system was created by a continuous outflow or a series of bursts from the nucleus of the central galaxy over the past 200-500 Myr. The cavities have displaced 10% of the plasma within a 300 kpc radius of the central galaxy, creating a swiss-cheese-like topology in the hot gas. The surface brightness decrements are consistent with empty cavities oriented within 40 degrees of the plane of the sky. The outflow has deposited upward of 10^61 erg into the cluster gas, most of which was propelled beyond the inner ~100 kpc cooling region. The supermassive black hole has accreted at a rate of approximately 0.1-0.25 solar masses per year over this time frame, which is a small fraction of the Eddington rate of a ~10^9 solar mass black hole, but is dramatically larger than the Bondi rate. Given the previous evidence for a circumnuclear disk of cold gas in Hydra A, these results are consistent with the AGN being powered primarily by infalling cold gas. The cavity system is shadowed perfectly by 330 MHz radio emission. Such low frequency synchrotron emission may be an excellent proxy for X-ray cavities and thus the total energy liberated by the supermassive black hole.Comment: 8 pages, 3 figures; Submitted to ApJ, revised per referee's suggestion

Wackiness and event management: the case of the World Alternative Games

The World Alternative Games (WAG) is a biennial event which takes place in Britain’s smallest town. This paper considers the ways in which wackiness is central to event spaces within the town of Llanwrtyd Wells, Wales. Based on a social constructivist approach, this work sheds light on aspects of the concept development, planning and organisation of events within a particular locale. It shows how wackiness is an important element of the event management development in the town and a key part of wider rural tourism development

Early Science with the Karoo Array Telescope: a Mini-Halo Candidate in Galaxy Cluster Abell 3667

Abell 3667 is among the most well-studied galaxy clusters in the Southern Hemisphere. It is known to host two giant radio relics and a head-tail radio galaxy as the brightest cluster galaxy. Recent work has suggested the additional presence of a bridge of diffuse synchrotron emission connecting the North-Western radio relic with the cluster centre. In this work, we present full-polarization observations of Abell 3667 conducted with the Karoo Array Telescope at 1.33 and 1.82 GHz. Our results show both radio relics as well as the brightest cluster galaxy. We use ancillary higher-resolution data to subtract the emission from this galaxy, revealing a localised excess, which we tentatively identify as a radio mini-halo. This mini-halo candidate has an integrated flux density of $67.2\pm4.9$ mJy beam$^{-1}$ at 1.37 GHz, corresponding to a radio power of P$_{\rm{1.4\,GHz}}=4.28\pm0.31\times10^{23}$ W Hz$^{-1}$, consistent with established trends in mini-halo power scaling.Comment: 17 pages, 10 figures, accepted MNRA

Density and Survival of Lady Beetles (Coccinellidae) in Overwintering Sites in Manitoba

The densities of lady beetles, Coccinellidae, overwintering as adults (adults per m2) in leaf litter collected in late October for two years in a beach-ridge forest on the south shore of Lake Manitoba were 56.4 for the Thirteen-spotted Lady Beetle, Hippodamia tredecimpunctata (Say), 38.3 for the Seven-spotted Lady Beetle, Coccinella septempunctata (L.), 7.7 for the Transverse Lady Beetle, Coccinella transversoguttata richardsonii Brown, 1.6 for the Convergent Lady Beetle, Hippodamia convergens Guerin, and 0.6 for the Parenthesis Lady Beetle, Hippodamia parenthesis (Say). The mean overwintering survival for these species was 0.254, 0.036, 0.023, 0.0, and 0.0, respectively. The density of overwintering coccinellids was highest near the margins of the forest, particularly on the beach side, where beetles from shore appear to have entered the forest. The mean density over 3 years (2.9 per m2) of all coccinellid species in November in the litter under a remnant grove of riverbank forest in Winnipeg, was lower than in the beach-ridge forest (104.8 per m2), but their survival (0.460) was higher than in the beach-ridge forest (0.154). More species of coccinellids were found in the samples from the riverbank forest than from the beach-ridge forest

Welcome to Microbial Informatics and Experimentation

Microbial Informatics and Experimentation (MIE) is a journal about computers and microbes. We created a new journal to fill a gap for which there is no publication avenue that is particularly geared to computationally-oriented, strongly biologically motivated, pragmatic articles focused on microbes. On the one hand, the bioinformatics journals are generally very computer technical and unlikely to be read by the diverse community of microbiologists. There is also a strong emphasis in bioinformatics literature on human/mammalian systems, though this is a secondary issue. On the other hand, microbial informatics work has appeared in a variety of microbiological publications, but it is seldom a good fit there either, and methods that span diverse microbes have no obvious home