A cryogenic surface-electrode elliptical ion trap for quantum simulation

Two-dimensional crystals of trapped ions are a promising system with which to implement quantum simulations of challenging problems such as spin frustration. Here, we present a design for a surface-electrode elliptical ion trap which produces a 2-D ion crystal and is amenable to microfabrication, which would enable higher simulated coupling rates, as well as interactions based on magnetic forces generated by on-chip currents. Working in an 11 K cryogenic environment, we experimentally verify to within 5% a numerical model of the structure of ion crystals in the trap. We also explore the possibility of implementing quantum simulation using magnetic forces, and calculate J-coupling rates on the order of 10^3 / s for an ion crystal height of 10 microns, using a current of 1 A

Macrophage migratory inhibitory factor (MIF) profiles are associated with indicators of physical and psychosocial stress in professional rugby league players

Introduction: MIF is an inflammatory cytokine which has a remarkable array of functions, including immune, metabolic and angiogenic effects. There is substantial evidence linking MIF to hypothalamic-pituitary-adrenal (HPA) axis functions, with MIF hypothesised to counter-regulate the anti-inflammatory actions of glucocorticoids (GC) at least partially by reducing the GC-sensitivity of immune cells. There is also evidence that changes in MIF are part of the well-established bi-directional links between psychological stress factors and dysregulation of inflammatory systems and HPA function. In professional athletes there is a unique combination of both physical and psychosocial stress which has been hypothesised to include immune dysfunction. The current study examined the association between indicators of physical and psychosocial stress on changes in MIF across a competitive season in professional rugby league players. Methods: Players (n=29) from a Sydney National Rugby League club participated in the study from February – August 2012. MIF was analysed in resting blood samples taken at least 24 hrs after the most recent exercise bout on six occasions approximately 1 month apart, with the first (baseline) sample taken prior to season start. From the same time points, data from standardised wellness questions was extracted from player diaries. Results: A significant effect of Time was observed in MIF levels (p\u3c.001), with a nadir at time 4 (May), and no difference between baseline and final samples (Feb-Aug). To determine salient associations, change in MIF from baseline to time 4 was calculated, and found to be negatively associated with the change over the same time period in stress/mood, sleep and muscle soreness, such that better mood, sleep quality and less muscle soreness were associated with lower levels of MIF. Conclusion: The current findings provide evidence that in a highly physically fit cohort, inflammatory markers are associated with indicators of both physical and psychosocial stress. MIF appears to be a reactive marker associated with stress and deserves further attention. Further, it may be important for athlete preparation to determine sleep and psychosocial stress influences on the homeostasis of inflammatory stress through GC function

Cardiac sarcoma presenting with abdominal pain and mimicking myxoma on echocardiogram

Cardiac sarcoma’s are highly aggressive tumours. Clear resection margins ± autotransplant, followed by chemotherapy, offers the best survival chance. Therefore, frozen section should be preformed when there is ambiguity in diagnosis

One Year of Alendronate Treatment Lowers Microstructural Stresses Associated with Trabecular Microdamage Initiation

Alendronate, an anti-remodeling agent, is commonly used to treat patients suffering from osteoporosis by increasing bone mineral density. Though fracture risk is lowered, an increase in microdamage accumulation has been documented in patients receiving alendronate, leading to questions about the potentially detrimental effects of remodeling suppression on the local tissue (material) properties. In this study, trabecular bone cores from the distal femur of beagle dogs treated for one year with alendronate, at doses scaled by weight to approximate osteoporotic and Paget's disease treatment doses in humans, were subjected to uniaxial compression to induce microdamage. Tissue level von Mises stresses were computed for alendronate-treated and non-treated controls using finite element analysis and correlated to microdamage morphology. Using a modified version of the Moore and Gibson classification for damage morphology, we determined that the von Mises stress for trabeculae exhibiting severe and linear microcrack patterns was decreased by approximately 25% in samples treated with alendronate compared with non-treated controls (p<0.01), whereas there was no reduction in the von Mises stress state for diffuse microdamage formation. Furthermore, an examination of the architectural and structural characteristics of damaged trabeculae demonstrated that severely damaged trabeculae were thinner, more aligned with the loading axis, and less mineralized than undamaged trabeculae in alendronate-treated samples (p<0.01). Similar relationships with damage morphology were found only with trabecular orientation in vehicle-treated control dogs. These results indicate that changes in bone's architecture and matrix properties associated with one year of alendronate administration reduce trabecular bone's ability to resist the formation of loading-induced severe and linear microcracks, both of which dissipate less energy prior to fracture than does diffuse damage