Characterisation of Cryogenic Material Properties of 3D-Printed Superconducting Niobium using a 3D Lumped Element Microwave Cavity

We present an experimental characterisation of the electrical properties of 3D-printed Niobium. The study was performed by inserting a 3D-printed Nb post inside an Aluminium cylindrical cavity, forming a 3D lumped element re-entrant microwave cavity resonator. The resonator was cooled to temperatures below the critical temperature of Niobium (9.25K) and then Aluminium (1.2K), while measuring the quality factors of the electromagnetic resonances. This was then compared with finite element analysis of the cavity and a measurement of the same cavity with an Aluminium post of similar dimensions and frequency, to extract the surface resistance of the Niobium post. The 3D-printed Niobium exhibited a transition to the superconducting state at a similar temperature to the regular Niobium, as well as a surface resistance of $3.1\times10^{-4}$ $\Omega$. This value was comparable to many samples of traditionally machined Niobium previously studied without specialised surface treatment. Furthermore, this study demonstrates a simple new method for characterizing the material properties of a relatively small and geometrically simple sample of superconductor, which could be easily applied to other materials, particularly 3D-printed materials. Further research and development in additive manufacturing may see the application of 3D-printed Niobium in not only superconducting cavity designs, but in the innovative technology of the future.Comment: 5 pages, 4 figure

The quality effects of agency staffing in residential aged care.

OBJECTIVES: In Australia, temporary agency workers are a relatively small but enduring component of the residential aged care workforce. However, evidence from other countries suggests reliance on agency workers has a detrimental effect on the quality of care (QoC). We examined whether QoC outcomes differ for Australian residential aged care facilities (RACFs) based on their reliance on agency care staff. METHODS: A retrospective observational study was conducted using de-identified datasets obtained under the legal authority of the Royal Commission into Aged Care Quality and Safety. Regression analysis was conducted using data comprising 6221 RACF-year observations, across 5 years (2015-2019), from 1709 unique RACFs in Australia. RESULTS: After controlling for other determinants of QoC, RACFs with a greater reliance on agency care staff have poorer QoC outcomes, with significantly higher rates of complaints, missing persons, reportable assaults, hospitalisations, and accreditation flags. CONCLUSIONS: Consistent with international evidence, we found that the QoC of Australian RACFs is sensitive to the reliance on agency staff in delivering direct care to residents. These findings illustrate the importance of workers' employment conditions, alongside other workforce characteristics, in driving the quality of residential aged care

A Protein‐Based Pentavalent Inhibitor of the Cholera Toxin B‐Subunit

Protein toxins produced by bacteria are the cause of many life-threatening diarrheal diseases. Many of these toxins, including cholera toxin (CT), enter the cell by first binding to glycolipids in the cell membrane. Inhibiting these multivalent protein/carbohydrate interactions would prevent the toxin from entering cells and causing diarrhea. Here we demonstrate that the site-specific modification of a protein scaffold, which is perfectly matched in both size and valency to the target toxin, provides a convenient route to an effective multivalent inhibitor. The resulting pentavalent neoglycoprotein displays an inhibition potency (IC50) of 104 pM for the CT B-subunit (CTB), which is the most potent pentavalent inhibitor for this target reported thus far. Complexation of the inhibitor and CTB resulted in a protein heterodimer. This inhibition strategy can potentially be applied to many multivalent receptors and also opens up new possibilities for protein assembly strategies

How can health promotion interventions be adapted for minority ethnic communities? Five principles for guiding the development of behavioural interventions.

The term ‘culturally sensitive’ is often used to describe interventions adapted for minority ethnic communities. However, understanding of strategies for adapting behavioural interventions for such communities is limited. The questions addressed in this paper are: What are the main strategies for adapting interventions to reduce coronary heart disease (CHD) for minority ethnic communities? Why have interventions been adapted in these ways? A systematic review was carried out to investigate interventions for preventing CHD, including promoting physical activity, smoking cessation and healthier diets in Pakistani, Chinese and Indian communities in countries where these groups are minorities. International databases and key websites were searched, and 23 477 titles and abstracts were initially identified. Seventeen papers met inclusion and quality criteria. A ‘meta-ethnographic’ approach to data synthesis was employed to identify underlying principles for adapting interventions. The rationale underpinning adaptations is not made explicit in individual studies, limiting generalizability. Five principles for adapting behavioural interventions for minority ethnic communities were identified: (i) use community resources to publicize the intervention and increase accessibility; (ii) identify and address barriers to access and participation; (iii) develop communication strategies which are sensitive to language use and information requirements; (iv) work with cultural or religious values that either promote or hinder behavioural change; and (v) accommodate varying degrees of cultural identification. While the principles require further testing and verification, they have been generated through a systematic approach to study identification, quality appraisal and data synthesis. This represents significant progress in advancing understanding of adapted behavioural interventions for minority ethnic communities

Real-time visualization of a sparse parametric mixture model for BTF rendering

Bidirectional Texture Functions (BTF) allow high quality visualization of real world materials exhibiting complex appearance and details that can not be faithfully represented using simpler analytical or parametric representations. Accurate representations of such materials require huge amounts of data, hindering real time rendering. BTFs compress the raw original data, constituting a compromise between visual quality and rendering time. This paper presents an implementation of a state of the art BTF representation on the GPU, allowing interactive high fidelity visualization of complex geometric models textured with multiple BTFs. Scalability with respect to the geometric complexity, amount of lights and number of BTFs is also studied.Fundação para a Ciência e Tecnologi

Desensitizing Inflation from the Planck Scale

A new mechanism to control Planck-scale corrections to the inflationary eta parameter is proposed. A common approach to the eta problem is to impose a shift symmetry on the inflaton field. However, this symmetry has to remain unbroken by Planck-scale effects, which is a rather strong requirement on possible ultraviolet completions of the theory. In this paper, we show that the breaking of the shift symmetry by Planck-scale corrections can be systematically suppressed if the inflaton field interacts with a conformal sector. The inflaton then receives an anomalous dimension in the conformal field theory, which leads to sequestering of all dangerous high-energy corrections. We analyze a number of models where the mechanism can be seen in action. In our most detailed example we compute the exact anomalous dimensions via a-maximization and show that the eta problem can be solved using only weakly-coupled physics.Comment: 34 pages, 3 figures

Characteristics of Ramachandran maps of L-alanine diamides as computed by various molecular mechanics, semiempirical and ab initio MO methods. A search for primary standard of peptide conformational stability

The optimized geometries and relative energies obtained by four force field and two semi-empirical methods were compared with ab initio results computed for formyl-L-alaninamide. Not all methods yielded the same number of minimum energy conformers. Furthermore, while the optimized geometries of the conformers found were comparable, the computed relative energies varied substantially. Also, the force field calculations produced Ramachandran maps that did not even have the appearance of the ab initio Ramachandran map. Correlating the ab initio relative energies (Delta E) or free energy (Delta G) with the log of relative populations, In(p(x)/p(gamma L)), led to linear relationships from which four conformers deviated; two of them (alpha(L) and epsilon(L)) were overly destabilized and two of them (gamma(L) and gamma(D)) were over-stabilized. It is suggested that, after such deviations are corrected, a primary standard may be obtained that might be useful in further investigations related to force-field parametrization as well as protein folding. (C) 1998 Elsevier Science B.V. All rights reserved

Axion monodromy in a model of holographic gluodynamics

The low energy field theory for N type IIA D4-branes at strong 't Hooft coupling, wrapped on a circle with antiperiodic boundary conditions for fermions, is known to have a vacuum energy which depends on the $\theta$ angle for the gauge fields, and which is a multivalued function of this angle. This gives a field-theoretic realization of "axion monodromy" for a nondynamical axion. We construct the supergravity solution dual to the field theory in the metastable state which is the adiabatic continuation of the vacuum to large values of $\theta$. We compute the energy of this state and show that it initially rises quadratically and then flattens out. We show that the glueball mass decreases with $\theta$, becoming much lower than the 5d KK scale governing the UV completion of this model. We construct two different classes of domain walls interpolating between adjacent vacua. We identify a number of instability modes -- nucleation of domain walls, bulk Casimir forces, and condensation of tachyonic winding modes in the bulk -- which indicate that the metastable branch eventually becomes unstable. Finally, we discuss two phenomena which can arise when the axion is dynamical; axion-driven inflation, and axion strings.Comment: 43 pages, 10 figures. v2: references update

Superpotential de-sequestering in string models

Non-perturbative superpotential cross-couplings between visible sector matter and K\"ahler moduli can lead to significant flavour-changing neutral currents in compactifications of type IIB string theory. Here, we compute corrections to Yukawa couplings in orbifold models with chiral matter localised on D3-branes and non-perturbative effects on distant D7-branes. By evaluating a threshold correction to the D7-brane gauge coupling, we determine conditions under which the non-perturbative corrections to the Yukawa couplings appear. The flavour structure of the induced Yukawa coupling generically fails to be aligned with the tree-flavour structure. We check our results by also evaluating a correlation function of two D7-brane gauginos and a D3-brane Yukawa coupling. Finally, by calculating a string amplitude between n hidden scalars and visible matter we show how non-vanishing vacuum expectation values of distant D7-brane scalars, if present, may correct visible Yukawa couplings with a flavour structure that differs from the tree-level flavour structure.Comment: 37 pages + appendices, 8 figure