Suppression of Kelvon-induced decay of quantized vortices in oblate Bose-Einstein Condensates

We study the Kelvin mode excitations on a vortex line in a three-dimensional trapped Bose-Einstein condensate at finite temperature. Our stochastic Gross-Pitaevskii simulations show that the activation of these modes can be suppressed by tightening the confinement along the direction of the vortex line, leading to a strong suppression in the vortex decay rate as the system enters a regime of two-dimensional vortex dynamics. As the system approaches the condensation transition temperature we find that the vortex decay rate is strongly sensitive to dimensionality and temperature, observing a large enhancement for quasi-two-dimensional traps. Three-dimensional simulations of the recent vortex dipole decay experiment of Neely et al. [Phys. Rev. Lett. 104, 160401 (2010)] confirm two-dimensional vortex dynamics, and predict a dipole lifetime consistent with experimental observations and suppression of Kelvon-induced vortex decay in highly oblate condensates.Comment: 8 pages, 8 figure

Interventions to help support caregivers of people with a brain or spinal cord tumour

Background The diagnosis and treatment of a brain or spinal cord tumour can have a huge impact on the lives of patients and their families with family caregiving often resulting in considerable burden and distress. Meeting the support needs of family caregivers is critical to maintain their emotional and physical health. Although support for caregivers is becoming more widely available, large‐scale implementation is hindered by a lack of high‐quality evidence for its effectiveness in the neuro‐oncology caregiver population. Objectives To assess the effectiveness of supportive interventions at improving the well‐being of caregivers of people with a brain or spinal cord tumour. To assess the effects of supportive interventions for caregivers in improving the physical and emotional well‐being of people with a brain or spinal cord tumour and to evaluate the health economic benefits of supportive interventions for caregivers. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 7), MEDLINE via Ovid, and Embase via Ovid. We also handsearched relevant published conference abstracts (previous five years), publications in the two main journals in the field (previous year), searched for ongoing trials via ClinicalTrials.gov, and contacted research groups in the field. The initial search was in March 2017 with an update in August 2018 (handsearches completed in January 2019). Selection criteria We included all randomised controlled trials (RCTs) where caregivers of neuro‐oncology patients constituted more than 20% of the sample and which evaluated changes in caregiver well‐being following any supportive intervention. Data collection and analysis Two review authors independently selected studies and carried out risk of bias assessments. We aimed to extract data on the outcomes of psychological distress, burden, mastery, quality of patient–caregiver relationship, quality of life, and physical functioning. Main results In total, the search identified 2102 records, of which we reviewed 144 in full text. We included eight studies. Four interventions focused on patient–caregiver dyads and four were aimed specifically at the caregiver. Heterogeneity of populations and methodologies precluded meta‐analysis. Risk of bias varied, and all studies included only small numbers of neuro‐oncology caregivers (13 to 56 participants). There was some evidence for positive effects of caregiver support on psychological distress, mastery, and quality of life (low to very low certainty of evidence). No studies reported significant effects on caregiver burden or quality of patient–caregiver relationship (low to very low certainty of evidence). None of the studies assessed caregiver physical functioning. For secondary outcomes (patient emotional or physical well‐being; health economic effects), we found very little to no evidence for the effectiveness of caregiver support. We identified five ongoing trials. Authors' conclusions The eight small‐scale studies included employed different methodologies across different populations, with low certainty of evidence overall. It is not currently possible to draw reliable conclusions regarding the effectiveness of supportive interventions aimed at improving neuro‐oncology caregiver well‐being. More high‐quality research is needed on support for family caregivers of people diagnosed, and living, with a brain or spinal cord tumour

IL-21 receptor expression in human tendinopathy

The pathogenetic mechanisms underlying tendinopathy remain unclear, with much debate as to whether inflammation or degradation has the prominent role. Increasing evidence points toward and early inflammatory infiltrate and associated inflammatory cytokine production in human and animal models of tendon disease. The IL-21/IL-21R axis is a proinflammatory cytokine complex that has been associated with chronic inflammatory diseases including rheumatoid arthritis and inflammatory bowel disease. This project aimed to investigate the role and expression of the cytokine/receptor pair IL-21/IL-21R in human tendinopathy. We found significantly elevated expression of IL-21 receptor message and protein in human tendon samples but found no convincing evidence of the presence of IL-21 at message or protein level. The level of expression of IL-21R message/protein in human tenocytes was significantly up regulated by proinflammatory cytokines (TNFα/IL-1β) in vitro. These findings demonstrate that IL-21R is present in early human tendinopathy mainly expressed by tenocytes and macrophages. Despite a lack of IL-21 expression these data again suggest that early tendinopathy has an inflammatory/cytokine phenotype, which may provide novel translational targets in the treatment of tendinopathy

Phase ordering and roughening on growing films

We study the interplay between surface roughening and phase separation during the growth of binary films. Already in 1+1 dimension, we find a variety of different scaling behaviors depending on how the two phenomena are coupled. In the most interesting case, related to the advection of a passive scalar in a velocity field, nontrivial scaling exponents are obtained in simulations.Comment: 4 pages latex, 6 figure

White-Tailed Deer are a Biotic Filter During Community Assembly, Reducing Species and Phylogenetic Diversity

Community assembly entails a filtering process, where species found in a local community are those that can pass through environmental (abiotic) and biotic filters and successfully compete. Previous research has demonstrated the ability of white-tailed deer (Odocoileus virginianus) to reduce species diversity and favour browse-tolerant plant communities. In this study, we expand on our previous work by investigating deer as a possible biotic filter altering local plant community assembly. We used replicated 23-year-old deer exclosures to experimentally assess the effects of deer on species diversity (H′), richness (SR), phylogenetic community structure and phylogenetic diversity in paired browsed (control) and unbrowsed (exclosed) plots. Additionally, we developed a deer-browsing susceptibility index (DBSI) to assess the vulnerability of local species to deer. Deer browsing caused a 12 % reduction in H′ and 17 % reduction in SR, consistent with previous studies. Furthermore, browsing reduced phylogenetic diversity by 63 %, causing significant phylogenetic clustering. Overall, graminoids were the least vulnerable to deer browsing based on DBSI calculations. These findings demonstrate that deer are a significant driver of plant community assembly due to their role as a selective browser, or more generally, as a biotic filter. This study highlights the importance of knowledge about the plant tree of life in assessing the effects of biotic filters on plant communities. Application of such knowledge has considerable potential to advance our understanding of plant community assembly

Characteristics of Two-Dimensional Quantum Turbulence in a Compressible Superfluid

Under suitable forcing a fluid exhibits turbulence, with characteristics strongly affected by the fluid's confining geometry. Here we study two-dimensional quantum turbulence in a highly oblate Bose-Einstein condensate in an annular trap. As a compressible quantum fluid, this system affords a rich phenomenology, allowing coupling between vortex and acoustic energy. Small-scale stirring generates an experimentally observed disordered vortex distribution that evolves into large-scale flow in the form of a persistent current. Numerical simulation of the experiment reveals additional characteristics of two-dimensional quantum turbulence: spontaneous clustering of same-circulation vortices, and an incompressible energy spectrum with $k^{-5/3}$ dependence for low wavenumbers $k$ and $k^{-3}$ dependence for high $k$.Comment: 7 pages, 7 figures. Reference [29] updated for v

Decellularization of human donor aortic and pulmonary valved conduits using low concentration sodium dodecyl sulfate

The clinical use of decellularised cardiac valve allografts is increasing. Long term data will be required to determine whether they outperform conventional cryopreserved allografts. Valves decellularised using different processes may show varied long-term outcomes. It is therefore important to understand the effects of specific decellularisation technologies on the characteristics of donor heart valves. Human cryopreserved aortic and pulmonary valved conduits were decellularised using hypotonic buffer, 0.1% (w/v) SDS and nuclease digestion. The decellularised tissues were compared to cellular cryopreserved valve tissues using histology, immunohistochemistry, quantitation of total DNA, collagen and glycosaminoglycan content, in vitro cytotoxicity assays, uniaxial tensile testing and subcutaneous implantation in mice. The decellularised tissues showed no histological evidence of cells or cell remnants and over 97% DNA removal in all regions (arterial wall, muscle, leaflet and junction). The decellularised tissues retained collagen IV and von Willebrand factor staining with some loss of fibronectin, laminin and chondroitin sulphate staining. There was an absence of MHC Class I staining in decellularised pulmonary valve tissues, with only residual staining in isolated areas of decellularised aortic valve tissues. The collagen content of the tissues was not decreased following decellularisation however the glycosaminoglycan content was reduced. Only moderate changes in the maximum load to failure of the tissues were recorded post-decellularisation. The decellularised tissues were non-cytotoxic in vitro, and were biocompatible in vivo in a mouse subcutaneous implant model. The decellularisation process will now be translated into a GMP compatible process for donor cryopreserved valves with a view to future clinical use

Eudaimonistic Argumentation

Virtue theories have lately enjoyed a modest vogue in the study of argumentation, echoing the success of more far-reaching programmes in ethics and epistemology. Virtue theories of argumentation (VTA) comprise several conceptually distinct projects, including the provision of normative foundations for argument evaluation and a renewed focus on the character of good arguers. Perhaps the boldest of these is the pursuit of the fully satisfying argument, the argument that contributes to human flourishing. This project has an independently developed epistemic analogue: eudaimonistic virtue epistemology. Both projects stress the importance of widening the range of cognitive goals beyond, respectively, cogency and knowledge; both projects emphasize social factors, the right sort of community being indispensable for the cultivation of the intellectual virtues necessary to each project. This paper proposes a unification of the two projects by arguing that the intellectual good life sought by eudaimonistic virtue epistemologists is best realized through the articulation of an account of argumentation that contributes to human flourishing