Quantum Hall induced currents and the magnetoresistance of a quantum point contact

We report an investigation of quantum Hall induced currents by simultaneous measurements of their magnetic moment and their effect on the conductance of a quantum point contact (QPC). Features in the magnetic moment and QPC resistance are correlated at Landau-level filling factors nu=1, 2 and 4, which demonstrates the common origin of the effects. Temperature and non-linear sweep rate dependences are observed to be similar for the two effects. Furthermore, features in the noise of the induced currents, caused by breakdown of the quantum Hall effect, are observed to have clear correlations between the two measurements. In contrast, there is a distinct difference in the way that the induced currents decay with time when the sweeping field halts at integer filling factor. We attribute this difference to the fact that, while both effects are sensitive to the magnitude of the induced current, the QPC resistance is also sensitive to the proximity of the current to the QPC split-gate. Although it is clearly demonstrated that induced currents affect the electrostatics of a QPC, the reverse effect, the QPC influencing the induced current, was not observed

High-voltage MOSFET bipolar square-wave generator

he construction of a high‐voltage (up to 1000 V) bipolar metal‐oxide‐semiconductor field‐effect transistor square‐wave generator is described. This generator is capable of producing both positive and negative going square waves with variable amplitude, repetition rate, and width. The circuit was designed for ferroelectrics research, however other applications are possible. The rise time of the prototype was 200 ns which was quite satisfactory for the present ferroelectric research project however the rise time can be decreased to 50 ns if necessary. The reader with a modest knowledge of electronics should be able to construct the circuit. Possible pitfalls and critical points are discussed

Conquering the great divide: Rural mothers of children with chronic health conditions accessing specialist medical care for their children

© 2019 Australian College of Nursing Ltd Background: Globally, the number of children with chronic health conditions (CHCs) is increasing and mothers are mostly responsible for their care. Aim: Few studies have focused on rural mothers and their experiences of sourcing health care for their children who have CHCs. The purpose of this study was to explore these experiences. Method: Using a phenomenological approach, semi-structured interviews were conducted in early 2018. The Consolidated criteria for Reporting Qualitative research (COREQ) guidelines were followed. Sixteen rural mothers were interviewed regarding their experiences of accessing health care to provide optimal management of their children's CHC. Findings: Thematic analysis of resulting data revealed the overarching theme ‘Conquering the great divide’. From this overarching theme, four themes emerged. This paper focuses on the first theme, ‘Heading to the big smoke: access’. Discussion: Rural mothers felt challenged accessing health care for their children in the major cities whilst also maintaining routine family life back home. Conclusion: Understanding these rural women's experiences could assist health care professionals to develop strategies to facilitate rural mothers accessing services for their children with a CHC

Recent results from the SLD using a highly polarized electron beam

New results are presented on the fermion asymmetries, A{sub b} and A{sub c}, and the b-branching ratio, R{sub b}, using a data sample of 150,000Z{degrees} decays collected by the SLD during 1993 and 1994. The fermion asymmetries exploit the highly polarized electron beam available at the SLC (63.0%{plus_minus}1.1% during 1993 and increasing to a preliminary value of 78.2%{plus_minus}2.0% during 1994) to perform direct measurements of A{sub b} and A{sub c}. The preliminary results obtained are A{sub b} = 0.82{plus_minus}0.06(stat){plus_minus}0.08(syst), A{sub c} = 0.63{plus_minus}0.13(stat){plus_minus}0.08(syst) and R{sub b} = 0.218{plus_minus}0.004(stat){plus_minus}0.004(syst){plus_minus}0.003(R{sub c}). In addition, the measurement of sin{sup 2} {theta}{sub W}{sup eff} from the 1993 A{sub LR} result is reviewed. The result obtained is sin{sup 2} {theta}{sub W}{sup eff} = 0.2292{plus_minus}0.0009(stat){plus_minus}0.0004(syst)

Causal Responsibility and Robust Causation

How do people judge the degree of causal responsibility that an agent has for the outcomes of her actions? We show that a relatively unexplored factor – the robustness (or stability) of the causal chain linking the agent’s action and the outcome – influences judgments of causal responsibility of the agent. In three experiments, we vary robustness by manipulating the number of background circumstances under which the action causes the effect, and find that causal responsibility judgments increase with robustness. In the first experiment, the robustness manipulation also raises the probability of the effect given the action. Experiments 2 and 3 control for probability-raising, and show that robustness still affects judgments of causal responsibility. In particular, Experiment 3 introduces an Ellsberg type of scenario to manipulate robustness, while keeping the conditional probability and the skill deployed in the action fixed. Experiment 4, replicates the results of Experiment 3, while contrasting between judgments of causal strength and of causal responsibility. The results show that in all cases, the perceived degree of responsibility (but not of causal strength) increases with the robustness of the action-outcome causal chain

Analysis of line x environment interactions for yield in navy beans. 3. Pattern analysis of environments over years

Yield trials of navy bean (Phaseolus vulgaris L.) lines were grown over a diverse range of locations for 7 years in Queensland, with changes in entries and locations in each year. The yield data were analysed over years using 3 recently developed pattern analysis techniques for the integration of historical, severely unbalanced data from plant breeding programs to derive relationships among environments in the way they discriminate among the entries grown in them. These techniques have been named as cumulative analysis, sequential analysis, and status analysis. The relationships among the locations for testing navy bean lines, although sensitive to the addition of new locations, quickly stabilised. These relationships were related to management (irrigation and row width) and latitude (north v. central v. Kingaroy v. southern Queensland)

Is There a Relationship Between Mating and Pathogenesis in Two Human Fungal Pathogens, Candida albicans and Candida glabrata?

This is the final version. Available on open access from Springer via the DOI in this recordPURPOSE OF REVIEW: Human fungal pathogens are rapidly increasing in incidence and readily able to evade the host immune responses. Our ability to study the genetic behind this has been limited due to the apparent lack of a sexual cycle and forward genetic tools. In this review, we discuss the evolution of mating, meiosis, and pathogenesis and if these processes are advantageous to pathogens. RECENT FINDINGS: This review summarises what is currently known about the sexual cycles of two important human fungal pathogens, Candida albicans and Candida glabrata. This includes the identification of parasexual cycle in C. albicans and the observed low levels of recombination in C. glabrata populations. SUMMARY: In this review, we present what is currently known about the mating types and mating/sexual cycles of two clinically important human fungal pathogens, Candida albicans and Candida glabrata. We discuss the evolution of meiosis using the knowledge that has been amassed from the decades of studying Saccharomyces cerevisiae and how this can be applied to fungal pathogens. We further discuss how the evolution of pathogenesis has played a role in influencing mating processes in human fungal pathogens and compare sexual cycles between C. albicans and C. glabrata, highlighting knowledge gaps and suggesting how these two fungi have evolved distinct mating niches to allow the development of disease in a human host.Biotechnology and Biological Sciences Research Council (BBSRC

Exchange interaction effects in inter-Landau level Auger scattering in a two-dimensional electron gas

We consider the influence of spin effects on the inter-Landau level electron-electron scattering rate in a two-dimensional electron gas. Due to the exchange spin splitting, the Landau levels are not equidistant. This leads to the suppresion of Auger processes and a nonlinear dependence of the lifetime on the concentration of the excited electrons even at very low excitation levels.Comment: 10 pages, 3 figure

The influence of the long-lived quantum Hall potential on the characteristics of quantum devices

Novel hysteretic effects are reported in magneto-transport experiments on lateral quantum devices. The effects are characterized by two vastly different relaxation times (minutes and days). It is shown that the observed phenomena are related to long-lived eddy currents. This is confirmed by torsion-balance magnetometry measurements of the same 2-dimensional electron gas (2DEG) material. These observations show that the induced quantum Hall potential at the edges of the 2DEG reservoirs influences transport through the devices, and have important consequences for the magneto-transport of all lateral quantum devices.Comment: 5 pages, 4 figure

Structure and play: rethinking regulation in the higher education sector

This paper explores possible tactics for academics working within a context of increasing regulation and constraint. One suggested tactic is to move outside of a creativity-conformity binary. Rather than understanding creativity and conformity as separable, where one is seen as excluding the other, the authors consider the potential of examining the relationships between them. The theme of 'structure and play' illustrates the argument. In the first part of the paper, using various examples from art and design - fields generally associated with creativity - the authors explore the interrelatedness of creativity and conformity. For example, how might design styles, which are generally understood as creative outcomes, constrain creativity and lead to conformity within the design field? Is fashion producing creativity or conformity? Conversely, the ways in which conformity provides the conditions for creativity are also examined. For example, the conformity imposed by the state on artists in the former communist bloc contributed to a thriving underground arts movement which challenged conformity and state regulation. Continuing the theme of 'structure and play', the authors recount a story from an Australian university which foregrounds the ongoing renegotiation of power relations in the academy. This account illustrates how programmatic government in a university, with its aim of regulating conduct, can contribute to unanticipated outcomes. The authors propose that a Foucauldian view of distributed power is useful for academics operating in a context of increasing regulation, as it brings into view sites where power might begin to be renegotiated