Publications by authors named "Bisset R"

We predict a rich excitation spectrum of a binary dipolar supersolid in a linear crystal geometry, where the ground state consists of two partially immiscible components with alternating, interlocking domains. We identify three Goldstone branches, each with first-sound, second-sound, or spin-sound character. In analogy with a diatomic crystal, the resulting lattice has a two-domain primitive basis and we find that the crystal (first-sound-like) branch is split into optical and acoustic phonons.

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Quantized vortices are a prototypical feature of superfluidity that have been observed in multiple quantum gas experiments. But the occurrence of vortices in dipolar quantum gases-a class of ultracold gases characterized by long-range anisotropic interactions-has not been reported yet. Here we exploit the anisotropic nature of the dipole-dipole interaction of a dysprosium Bose-Einstein condensate to induce angular symmetry breaking in an otherwise cylindrically symmetric pancake-shaped trap.

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Angular oscillations can provide a useful probe of the superfluid properties of a system. Such measurements have recently been applied to dipolar supersolids, which exhibit both density modulation and phase coherence, and for which robust probes of superfluidity are particularly interesting. So far, these investigations have been confined to linear droplet arrays, which feature relatively simple excitation spectra, but limited sensitivity to the effects of superfluidity.

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Dipolar condensates have recently been coaxed to form the long-sought supersolid phase. While one-dimensional supersolids may be prepared by triggering a roton instability, we find that such a procedure in two dimensions (2D) leads to a loss of both global phase coherence and crystalline order. Unlike in 1D, the 2D roton modes have little in common with the supersolid configuration.

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Supersolid states simultaneously feature properties typically associated with a solid and with a superfluid. Like a solid, they possess crystalline order, manifesting as a periodic modulation of the particle density; but unlike a typical solid, they also have superfluid properties, resulting from coherent particle delocalization across the system. Such states were initially envisioned in the context of bulk solid helium, as a possible answer to the question of whether a solid could have superfluid properties.

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Recently achieved two-component dipolar Bose-Einstein condensates open exciting possibilities for the study of mixtures of ultradilute quantum liquids. While nondipolar self-bound (without external confinement) mixtures are necessarily miscible with an approximately fixed ratio between the two densities, the density ratio for the dipolar case is free. Therefore, self-bound dipolar mixtures present qualitatively novel and much richer physics, characterized by three possible ground-state phases: miscible, symmetric immiscible, and asymmetric immiscible, which may in principle occur at any population imbalance.

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This brief addresses understandability of modern machine learning networks with respect to the statistical properties of their convolution layers. It proposes a set of tools for categorizing a convolution layer in terms of kernel property (meanlet, differencelet, or distrotlet) or kernel sequence property (frame spectra and intralayer correlation matrix). These tools are expected to be relevant for determining the generalization capabilities of a convolutional neural network.

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The competition of dipole-dipole and contact interactions leads to exciting new physics in dipolar gases, well illustrated by the recent observation of quantum droplets and rotons in dipolar condensates. We show that the combination of the roton instability and quantum stabilization leads under proper conditions to a novel regime that presents supersolid properties due to the coexistence of stripe modulation and phase coherence. In a combined experimental and theoretical analysis, we determine the parameter regime for the formation of coherent stripes, whose lifetime of a few tens of milliseconds is limited by the eventual destruction of the stripe pattern due to three-body losses.

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We describe the case of an 89-year-old man who developed delirium following the introduction of fesoterodine to treat his urgency incontinence. The patient started experiencing visual hallucinations approximately five days after starting fesoterodine 4 mg once daily. Delirium resolved after fesoterodine was stopped.

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We present a theory for the number fluctuations of a quasi-two-dimensional (quasi-2D) dipolar Bose-Einstein condensate measured with finite resolution cells. We show that when the dipoles are tilted to have a component parallel to the plane of the trap, the number fluctuations become anisotropic, i.e.

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We demonstrate that measurements of atom-number fluctuations in a trapped dipolar condensate can reveal the presence of the elusive roton excitation. The key signature is a super-Poissonian peak in the fluctuations as the size of the measurement cell is varied, with the maximum occurring when the size is comparable to the roton wavelength. The magnitude of this roton feature is enhanced with temperature.

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Background: A preoperative surgical safety checklist was implemented into three major hospitals performing elective operations in Christchurch (New Zealand) in 2004. A prospective analysis of the results of this "Time Out Procedure" (TOP) was performed upon its implementation and 4 years later.

Methods: All members of the surgical team who participated in the TOP were recorded, as were the details of any discrepancies encountered during the TOP.

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Introduction: Colonic cancer presenting as a remote abscess in the gluteal region, abdominal wall, retroperitoneal region, groin or thigh is rare.

Case Report: We report a case of advanced carcinoma of the caecum in an elderly lady without bowel symptoms presenting as right gluteal abscess.

Discussion: In the differential diagnosis of gluteal/ upper thigh abscess the rare possibility of colonic cancer perforation as a cause should be considered.

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Aim: To determine the accuracy and define the limitations of post mortem magnetic resonance imaging (MRI) in determining the cause of sudden death in adults.

Methods And Results: Sudden unexpected adult deaths in the community, reported to the Coroner (n = 10), excluding suspicious, violent or potentially drug-related deaths, were submitted to whole body MRI, followed by full invasive autopsy. The MRI scans were reported independently by four radiologists, blinded to the autopsy findings; two had previous experience of post mortem MRI.

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A chronic clinical course for intussusception of the bowel in children is an unusual, but well recognized phenomenon. We report a case of a young child whose symptoms of vomiting and abdominal pains continued for over a month before radiological investigation made the diagnosis of ileocolic intussusception which was then successfully reduced by air enema.

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Medical students and clinicians have, for generations, based their knowledge and application of anatomy on the study of cadavers which have been fixed in formalin. Assumptions are made that structures maintain the same relationship in the living as in the dead. Such a belief is untrue in respect of the inferior extent of the lung and pleura into the posterior diaphragmatic sulcus.

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Achalasia of the cardia is an uncommon condition with an incidence of 0.1 cases per year per 100,000 population under 14 years. A review of experience at Booth Hall Children's Hospital over the past 10 years has revealed six cases of achalasia in children.

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Iodine delivery rates (IDR) of five commonly used non-ionic contrast media were determined at room temperature (24 degrees C) and body temperature (37 degrees C). Contrast media of strength 300 mgI/ml were also evaluated at 50% dilution (150 mgI/ml) with N-saline. Iodine delivery differed significantly (p less than 0.

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