Climatic role of Southern Hemisphere extratropical cyclones and their relationship with sea ice

Transient atmospheric systems play a central role in determining the climate of the high southern latitudes. Accordingly, the variability of these features and the mechanisms which cause it are important considerations for the (palaeo)climatologist. One element which might have been expected to be intimately tied up with cyclonic activity is the extent of sea ice encircling the Antarctic continent. We refer to studies which suggest relationships between sea ice and cyclones on synoptic time-scales, but in which these become very weak when interannual relationships are considered. We have analysed the reasons for this apparently contradictory behaviour. It is suggested that the intuitive appeal of an ice-cyclone connection has an implicit and characteristic time-scale (of a few hours or days) associated with it. However, the same reasoning cannot be applied to longer periods, because of the nonlinearities in the links between the two factors. This, in particular, cautions against the use of simplistic arguments when trying to estimate the locations of storm tracks during epochs when seaicc coverage was very different from that obtaining during the insttumental record

Invoking posthumanist vistas: A diffractive gaze on curriculum practices and potential

Humanist discourse has assumed such an ideological normalcy to the extent that any attempts at its disruption are likely to be met with severe resistance. As such, higher education curriculum design and curriculum content continue to be largely anthropocentric, buoyed by human-centred neoliberal principles that have gradually encroached the academe. To explore ways out of the dilemma, we draw on wild pedagogy theory (Jickling 2015; Mcphie and Clarke 2015; Springgay and Zaliwska 2017; Jickling et al. 2018b) as a means to challenge the straitjacket constraints of neoliberal higher education. Over time, the wild has been banished from classrooms: the call for wild pedagogies might mean that we have reached the limits of the “tamed” ‒ and we have tamed a lot in order to offer a “one size fits all” approach to (higher) education (Jickling et al. 2018a). The tendency for higher education to teach more and more people in less and less time, has implied an understanding of teaching that is characterised by efficiency and processing, at the cost of the process of learning as a relational becoming with the world in the posthuman condition we live in (Braidotti 2019). In this article, vignettes are used to offer an account of our critical posthumanist incursions as university lecturers into curriculum practices. We use a diffractive gaze to present the generative potential of non-anthropocentric approaches as well as the struggles that these present as we strive to de-center our humanistic tendencies towards curriculum knowledge and teaching within the neoliberal space, we find ourselves

Parametric coupling between macroscopic quantum resonators

Time-dependent linear coupling between macroscopic quantum resonator modes generates both a parametric amplification also known as a {}"squeezing operation" and a beam splitter operation, analogous to quantum optical systems. These operations, when applied properly, can robustly generate entanglement and squeezing for the quantum resonator modes. Here, we present such coupling schemes between a nanomechanical resonator and a superconducting electrical resonator using applied microwave voltages as well as between two superconducting lumped-element electrical resonators using a r.f. SQUID-mediated tunable coupler. By calculating the logarithmic negativity of the partially transposed density matrix, we quantitatively study the entanglement generated at finite temperatures. We also show that characterization of the nanomechanical resonator state after the quantum operations can be achieved by detecting the electrical resonator only. Thus, one of the electrical resonator modes can act as a probe to measure the entanglement of the coupled systems and the degree of squeezing for the other resonator mode.Comment: 15 pages, 4 figures, submitte

Dynamics of thermoelastic thin plates: A comparison of four theories

Four distinct theories describing the flexural motion of thermoelastic thin plates are compared. The theories are due to Chadwick, Lagnese and Lions, Simmonds, and Norris. Chadwick's theory requires a 3D spatial equation for the temperature but is considered the most accurate as the others are derivable from it by different approximations. Attention is given to the damping of flexural waves. Analytical and quantitative comparisons indicate that the Lagnese and Lions model with a 2D temperature equation captures the essential features of the thermoelastic damping, but contains systematic inaccuracies. These are attributable to the approximation for the first moment of the temperature used in deriving the Lagnese and Lions equation. Simmonds' model with an explicit formula for temperature in terms of plate deflection is the simplest of all but is accurate only at low frequency, where the damping is linearly proportional to the frequency. It is shown that the Norris model, which is almost as simple as Simmond's, is as accurate as the more precise but involved theory of Chadwick.Comment: 2 figures, 1 tabl

Coherent quantum state storage and transfer between two phase qubits via a resonant cavity

A network of quantum-mechanical systems showing long lived phase coherence of its quantum states could be used for processing quantum information. As with classical information processing, a quantum processor requires information bits (qubits) that can be independently addressed and read out, long-term memory elements to store arbitrary quantum states, and the ability to transfer quantum information through a coherent communication bus accessible to a large number of qubits. Superconducting qubits made with scalable microfabrication techniques are a promising candidate for the realization of a large scale quantum information processor. Although these systems have successfully passed tests of coherent coupling for up to four qubits, communication of individual quantum states between qubits via a quantum bus has not yet been demonstrated. Here, we perform an experiment demonstrating the ability to coherently transfer quantum states between two superconducting Josephson phase qubits through a rudimentary quantum bus formed by a single, on chip, superconducting transmission line resonant cavity of length 7 mm. After preparing an initial quantum state with the first qubit, this quantum information is transferred and stored as a nonclassical photon state of the resonant cavity, then retrieved at a later time by the second qubit connected to the opposite end of the cavity. Beyond simple communication, these results suggest that a high quality factor superconducting cavity could also function as a long term memory element. The basic architecture presented here is scalable, offering the possibility for the coherent communication between a large number of superconducting qubits.Comment: 17 pages, 4 figures (to appear in Nature

"Fortunate are those who take the first steps"? The psychosocial impact of novel drug development.

Novel drug development offers people with cystic fibrosis exciting opportunities but is not without challenges. Currently, there is an understandable emphasis on protecting patients' physical health when developing treatments. However, there appears to be little consideration of how novel drug development impacts on psychosocial wellbeing, or the downstream consequences of this. Using an illustrative case and reviewing the literature we explore themes regarding the psychosocial impact of trial participation and novel drug development and identify areas requiring further research. Through this, we hope to prepare healthcare professionals to better understand the needs of their patients in this rapidly evolving landscape

Measurement crosstalk between two phase qubits coupled by a coplanar waveguide

We analyze the measurement crosstalk between two flux-biased phase qubits coupled by a resonant coplanar waveguide cavity. After the first qubit is measured, the superconducting phase can undergo damped oscillations resulting in an a.c. voltage that produces a frequency chirped noise signal whose frequency crosses that of the cavity. We show experimentally that the coplanar waveguide cavity acts as a bandpass filter that can significantly reduce the crosstalk signal seen by the second qubit when its frequency is far from the cavity's resonant frequency. We present a simple classical description of the qubit behavior that agrees well with the experimental data. These results suggest that measurement crosstalk between superconducting phase qubits can be reduced by use of linear or possibly nonlinear resonant cavities as coupling elements.Comment: 4 pages, 3 figure