Conservation of Angular Momentum in a Flux Qubit

Oscillations of superconducting current between clockwise and counterclockwise directions in a flux qubit do not conserve the angular momentum of the qubit. To compensate for this effect the solid containing the qubit must oscillate in unison with the current. This requires entanglement of quantum states of the qubit with quantum states of a macroscopic body. The question then arises whether slow decoherence of quantum oscillations of the current is consistent with fast decoherence of quantum states of a macroscopic solid. This problem is analyzed within an exactly solvable quantum model of a qubit embedded in an absolutely rigid solid and for the elastic model that conserves the total angular momentum. We show that while the quantum state of a flux qubit is, in general, a mixture of a large number of rotational states, slow decoherence is permitted if the system is macroscopically large. Practical implications of entanglement of qubit states with mechanical rotations are discussed.Comment: 10 page

Quantum Tunneling of the Magnetic Moment in a Free Particle

We study tunneling of the magnetic moment in a particle that has full rotational freedom. Exact energy levels are obtained and the ground-state magnetic moment is computed for a symmetric rotor. The effect of the mechanical freedom on spin tunneling manifests itself in a strong dependence of the magnetic moment on the moments of inertia of the rotor. Energy of the particle exhibits quantum phase transitions between states with different values of the magnetic moment. Particles of various shapes are investigated and quantum phase diagram is obtained.Comment: 7 Figures, 5 Figure Captions, submitted to PR

On the interaction of rate-induced and bifurcation-induced tipping in ecosystems

We analyse nonlinear tipping phenomena in a bi-stable ecosystem model, defined as sudden and unexpected transitions from the herbivore-dominating equilibrium to the plant-only equilibrium, which are triggered by environmental changes represented by time-varying parameters [Scheffer et al. {\em Ecosystems} 11 2008]. We obtain simple criteria for tipping in terms of properties of the autonomous system with fixed in time parameters. Specifically, we use classical bifurcation analysis to identify a codimension-three degenerate Bogdanov-Takens bifurcation: the organising centre for bifurcation-induced tipping (B-tipping) and the source of a dangerous subcritical Hopf bifurcation. We introduce basin instability analysis to identify parameter paths along which rate-induced tipping (R-tipping) is guaranteed to occur without crossing any bifurcation. We then produce tipping diagrams for the non-autonomous system with time-varying parameters in the plane of the magnitude and rate of a parameter shift to reveal tipping-tracking transitions due to maximal-canard solutions that, perhaps surprisingly, follow unstable states for infinite time. We also uncover non-trivial dynamics arising from the interaction between B-tipping and R-tipping. Given a monotone parameter shift that causes tipping, we ask if tipping can be prevented upon a parameter trend reversal. The ensuing analysis of non-monotone parameter shifts reveals an intriguing tipping diagram with a single critical level and multiple critical rates, indicating that the system switches from tipping to tracking and back to tipping again as the rate of the parameter shift increases. In the diagram, we identify points of no return where tipping cannot be prevented by the parameter trend reversal and points of return tipping where tipping is inadvertently induced by the parameter trend reversal. The results give new insight into the sensitivity of ecosystems to the magnitudes and rates of environmental change. A comparison of the ecosystem model with modified saddle-node and subcritical Hopf normal forms shows that the tipping diagram is characteristic of a non-monotone passage through a basin instability boundary and a generic dangerous bifurcation in nonlinear systems in general

An evaluation of water treatment technologies for sustainable rural communities

This paper presents the initial stages of research funded by the Scottish Government to enable an evaluation of the suitability of drinking water treatment technologies at small to medium scales to facilitate the application of the Scottish Government’s Sustainable Rural Communities concept. The research included a technology scan to identify relevant drinking water treatment technologies suitable for small and medium sized rural communities in Scotland and an expert stakeholder workshop to verify and refine the technology inventory. The stakeholder workshop was also used to identify suitable selection criteria for Sustainable Rural Community drinking water projects. The criteria can be used in subsequent multi-stakeholder decision making for the most sustainable treatment options for specific communities. An explanation is provided on the methodology and the types of information that were collected and the outcomes of the research. <br/

Setting an ethical direction – how the UK Covid-19 public inquiry can learn from research in the arts and humanities. A ‘meta-analysis’ of research from the Pandemic & Beyond portfolio

This is the final version. Available via the link in this recordExecutive Summary This report has been commissioned to assist the UK COVID-19 Public Inquiry’s task to understand and evaluate the preparations and response to COVID-19 in the UK. It draws on findings from a set of research projects funded by the Arts and Humanities Research Council (AHRC) to consider the pandemic’s impacts as these unfolded. The research not only offers substantial academic contributions on subjects relevant to the Inquiry’s deliberations; they also help us centralise ethical reflection as an inevitable component of the Inquiry’s task. In reviewing the evidence of the actions that have and have not been taken over the past two years, this report proposes that the UK Inquiry can and should help us set an ethical direction for the UK moving forward. The most salient and highest level, message summarising findings across the 26 projects included within this study concerns the extent, interconnectedness and urgency of the structural problems that the pandemic has brought into view. The corpus shows how individuals and communities who were socially, economically, culturally disadvantaged before the pandemic were disproportionately harmed by it. This message applies across the diverse contexts over which the corpus ranges, from inequalities in digital access; to racial discrimination in health settings; via unequal access to green spaces for communities; to funding disparities in the cultural sector. Moreover, the strategies the government employed to protect the UK population sometimes reinforced and worsened those disadvantages. It is not the Inquiry’s task to establish what equitable policy choices and effective political decision-making might mitigate these structural inequalities. However, by recognising them, it will demonstrate that future resilience planning to effect a fairer distribution of the costs and protections in any future emergencies depends on a strategic and longer-term ambition to ensure a fairer society. In setting an ethical direction, the Public Inquiry should: ● Acknowledge the role of structural and place-based health inequalities in the pandemic. ● Urge the UK government to take responsibility for these inequalities. ● Encourage the UK government to initiate equitable social policy solutions where harms and impacts are identified. ● Confront the harms to democratic governance and promote democratic debate over a future ‘social covenant’. ● Underline the facility of arts and humanities research for ethical review and future policy makingArts and Humanities Research Council (AHRC

Psychodynamic psychotherapy for children and adolescents: an updated narrative review of the evidence-base

While the evidence base for psychodynamic therapy with adults is now quite substantial, there is still a lack of research evaluating the effectiveness of psychodynamic therapies with children and young people. Those studies that have been carried out are also not widely known in the field. To help address the second point, in 2011, we carried out a review of the evidence base for psychodynamic psychotherapy for children and adolescents, which identified 35 studies which together provided some preliminary evidence for this treatment for a range of childhood disorders. The present study is an updated review, focusing on research published between March 2011 and November 2016. During this period, 23 additional studies were published, of which 5 were reports on randomised controlled trials, 3 were quasi-experimental controlled studies and 15 were observational studies. Although most studies covered children with mixed diagnoses, there were a number of studies examining specific diagnostic groups, including children with depression, anxiety and disruptive disorders. whilst the quality of studies was mixed, some were well-designed and reported, and overall indicated promising findings. Nevertheless, further high-quality research is needed in order to better understand the effectiveness of psychodynamic psychotherapy across a range of different disorders, and to ensure that services can provide a range of evidence-based treatments for children and young people

The impact of ship emission controls recorded by cloud properties

The impact of aerosols on cloud properties is one of the leading uncertainties in the human forcing of the climate. Ships are large, isolated sources of aerosol creating linear cloud formations known as shiptracks. These are an ideal opportunity to identify and measure aerosol-cloud interactions. This work uses over 17,000 shiptracks during the implementation of fuel sulphur content regulations to demonstrate the central role of sulphate aerosol in ship exhaust for modifying clouds. By connecting individual shiptracks to transponder data, it is shown that almost half of shiptracks are likely undetected, masking a significant contribution to the climate impact of shipping. A pathway to retrieving ship sulphate emissions is demonstrated, showing how cloud observations could be used to monitor air pollution

Induction of A9 dopaminergic neurons from neural stem cells improves motor function in an animal model of Parkinson's disease

Neural stem cells (NSCs) are widely endorsed as a cell source for replacement strategies in neurodegenerative disease. However, their usefulness is currently limited by the inability to induce specific neurotransmitter phenotypes in these cells. In order to direct dopaminergic neuronal fate, we overexpressed Pitx3 in NSCs that were then exposed to E11 developing ventral mesencephalon (VM) in explant culture. This resulted in a significant potentiation of dopaminergic differentiation of the cells. When transplanted into the 6-hydroxydopamine lesioned Parkinsonian rats, these cografts of VM and Pitx3 overexpressing NSCs resulted in a significant restitution of motor function. In addition, there were greater numbers of Girk2 positive A9 neurons in the periphery of the transplants that were NSC derived. This demonstrates that given the correct signals, NSCs can be induced to become dopaminergic neurons that can differentiate into the correct nigrastriatal phenotype required for the treatment of Parkinson's diseas

Symmetric coalescence of two hydraulic fractures.

The formation of a fracture network is a key process for many geophysical and industrial practices from energy resource recovery to induced seismic management. We focus on the initial stage of a fracture network formation using experiments on the symmetric coalescence of two equal coplanar, fluid-driven, penny-shaped fractures in a brittle elastic medium. Initially, the fractures propagate independently of each other. The fractures then begin to interact and coalesce, forming a bridge between them. Within an intermediate period after the initial contact, most of the fracture growth is localized along this bridge, perpendicular to the line connecting the injection sources. Using light attenuation and particle image velocimetry to measure both the fracture aperture and velocity field, we characterize the growth of this bridge. We model this behavior using a geometric volume conservation argument dependent on the symmetry of the interaction, with a 2D approximation for the bridge. We also verify experimentally the scaling for the bridge growth and the shape of the thickness profile along the bridge. The influence of elasticity and toughness of the solid, injection rate of the fluid, and initial location of the fractures are captured by our scaling

Comparison of Glasgow Admission Prediction Score and Amb Score in predicting need for inpatient care.

AIM: We compared the abilities of two established clinical scores to predict emergency department (ED) disposition: the Glasgow Admission Prediction Score (GAPS) and the Ambulatory Score (Ambs). METHODS: The scores were compared in a prospective, multicentre cohort study. We recruited consecutive patients attending ED triage at two UK sites: Northern General Hospital in Sheffield and Glasgow Royal Infirmary, between February and May 2016. Each had a GAPS and Ambs calculated at the time of triage, with the triage nurses and treating clinicians blinded to the scores. Patients were followed up to hospital discharge. The ability of the scores to discriminate discharge from ED and from hospital at 12 and 48 hours after arrival was compared using the area under the curve (AUC) of their receiving-operator characteristics (ROC). RESULTS: 1424 triage attendances were suitable for analysis during the study period, of which 567 (39.8%) were admitted. The AUC for predicting admission was significantly higher for GAPS at 0.807 (95% CI 0.785 to 0.830), compared with 0.743 (95% CI 0.717 to 0.769) for Ambs, P12 hour and >48 hour. GAPS was also more accurate as a binary test, correctly predicting 1057 outcomes compared with 1004 for Ambs (74.2vs70.5%, P=0.012). CONCLUSION: The GAPS is a significantly better predictor of need for hospital admission than Ambs in an unselected ED population