Quantum Backflow States from Eigenstates of the Regularized Current Operator

We present an exhaustive class of states with quantum backflow -- the phenomenon in which a state consisting entirely of positive momenta may have negative current and the probability flows in the opposite direction to the momentum. They are characterized by a general function of momenta subject to very weak conditions. Such a family of states is of interest in the light of a recent experimental proposal to measure backflow. We find one particularly simple state which has surprisingly large backflow -- about 41 percent of the lower bound on flux derived by Bracken and Melloy. We study the eigenstates of a regularized current operator and we show how some of these states, in a certain limit, lead to our class of backflow states. This limit also clarifies the correspondence between the spectrum of the regularized current operator, which has just two non-zero eigenvalues in our chosen regularization, and the usual current operator.Comment: 16 pages, 2 figure

Marketing 'development' in the neoliberal university: A critical insight into UK Higher Education Institutions

UK higher education institutions (HEIs) are in competition with each other and HEIs across the globe for fee-paying students within a higher education model that promotes neoliberal values of individualism and competition in a global free market. This creates the conditions for the neoliberal university to actively market itself and its products in an international marketplace of potential students. We analyse three dominate frames employed by universities to do this: brand recognition, a discourse on the creation of global workers, and an emphasis on a degree as a product that is bought and sold. Current literature on marketing and HEIs focuses on how marketing works with the university as the unit of analysis, whereas the contribution of this paper is to advance critical insight into university marketing practices at the level of a specific discipline – development studies - with the intention to deepen our understanding of the effects of marketing practices on the discipline. That is, we ask in marketing development programmes what precisely is sold? Thus, we critically examine representations of ‘development’ within the development industry and explore the marketing of ‘development’ as a neoliberal product that it is conceptualised and sold by northern development actors to primarily northern audiences. We identify five key ideas of ‘development’ that are sold to northern publics: ‘development’ as a positive association for an individual, a commodity, an act of global citizenship, an exercise in northern nation branding and taking a broader perspective, ‘development’ as an overly simplistic, racist and misogynist trope. Bringing together these two distinct literatures, we present a conceptual framework to lead deeper enquiry into what is sold and how when marketing ‘development’ in the neoliberal university. Through this paper we aim to draw attention to the potential for contestation that can emerge between ethical and considerate representations of ‘development’ and the effective marketing of development studies programmes to fee-paying students

Enhancement of quantum dot peak-spacing fluctuations in the fractional q uantum Hall regime

The fluctuations in the spacing of the tunneling resonances through a quantum dot have been studied in the quantum Hall regime. Using the fact that the ground-state of the system is described very well by the Laughlin wavefunction, we were able to determine accurately, via classical Monte Carlo calculations, the amplitude and distribution of the peak-spacing fluctuations. Our results clearly demonstrate a big enhancement of the fluctuations as the importance of the electronic correlations increases, namely as the density decreases and filling factor becomes smaller. We also find that the distribution of the fluctuations approaches a Gaussian with increasing density of random potentials.Comment: 6 pages, 3 figures all in gzipped tarred fil

Activation of the P2Y2 receptor regulates bone cell function by enhancing ATP release

Bone cells constitutively release ATP into the extracellular environment where it acts locally via P2 receptors to regulate bone cell function. Whilst P2Y2 receptor stimulation regulates bone mineralisation, the functional effects of this receptor in osteoclasts remain unknown. This investigation used the P2Y2 receptor knockout (P2Y2R−/−) mouse model to investigate the role of this receptor in bone. MicroCT analysis of P2Y2R−/− mice demonstrated age-related increases in trabecular bone volume (≤48%), number (≤30%) and thickness (≤17%). In vitro P2Y2R−/− osteoblasts displayed a 3-fold increase in bone formation and alkaline phosphatase activity, whilst P2Y2R−/− osteoclasts exhibited a 65% reduction in resorptive activity. Serum cross-linked C-telopeptide levels (CTX, resorption marker) were also decreased (≤35%). The resorption defect in P2Y2R−/− osteoclasts was rescued by the addition of exogenous ATP, suggesting that an ATP deficit could be a key factor in the reduced function of these cells. In agreement, we found that basal ATP release was reduced up to 53% in P2Y2R−/− osteoclasts. The P2Y2 receptor agonists, UTP and 2-thioUTP, increased osteoclast activity and ATP release in wild-type but not in P2Y2R−/− cells. This indicates that the P2Y2 receptor may regulate osteoclast function indirectly by promoting ATP release. UTP and 2-thioUTP also stimulate ATP release from osteoblasts suggesting that the P2Y2 receptor exerts a similar function in these cells. Taken together, our findings are consistent with the notion that the primary action of P2Y2 receptor signalling in bone is to regulate extracellular ATP levels

Structurally Unsound - Exploring Inequalities: Igniting research to better inform UK policy

Inequalities are deeply embedded in our society, permeating throughout our social structures and institutions. Legislative responses that outlaw discriminatory behaviours and promote positive change are an essential part of the battle, but the structural nature of horizontal inequalities (that is, those that apply to entire groups such as women, disabled people, LGBT individuals, and people of colour rather than just at the individual level) mean that they are not necessarily sufficient. That is particularly the case once we account for additional complications associated with the intersection of various forms of horizontal inequality. The inequalities faced by women of colour are not simply those faced by white women with a racial element ‘added on’: they are fundamentally different. Making further progress rests, as ever, on securing political and social will for change. But it rests too on further developing the evidence base – both in terms of more accurately capturing the nuance of the problem statement, and better understanding what works when it comes to policy interventions. It is that goal which this project has pursued. Over the course of nine months, UCL and the Resolution Foundation have convened a series of roundtables and undertaken interviews with research and policy experts from a range of disciplines, policy areas, sectors and locations. Five cross‑cutting themes have emerged that we believe warrant consideration by all members of the research and policymaking communities that want to more effectively tackle structural inequalities in the UK: * Language / * Opportunity / * Understanding evidence / * Voice / * Place / We construct a deliberately technocratic list of lessons that researchers and policymakers should consider when thinking about how to better approach the study and treatment of structural inequalities. In this way, we hope to spread best practice and help plug the gaps in understanding that our expert engagement identified

Prevalence of high risk HPV in HIV+ and HIV- women with cervical dysplasia at the Moi Teaching and Referral Hospital

Background: Cervical cancer, caused by Human Papillomavirus, is the second commonest cancer among women. HIV+ women are at a higher risk of acquiring HPV, developing pre-cervical cancer lesions (dysplasia) and cervical cancer. Early diagnosis is key to prevention of cervical cancer but reduced sensitivities and specificities of available screening methods pose challenges. The role of HPV in VIA related dysplasia has not been extensively interrogated. We sought to understand HPV infection in the context of HIV status and its relationship to VIA dysplasiaObjectives: To compare prevalence of high risk HPV in HIV positive and HIV negative women with and without cervical dysplasia.Study Design: A cross sectional study design.Setting: AMPATH/MTRH cervical cancer and prevention program clinic located at the Moi Teaching and Referral Hospital provides cervical cancer screening services for women.Participants: Women attending cervical cancer screening clinicsResults: A total of 88 women were enrolled into the study. HR HPV prevalence was 59.1% among HIV+ and 43.2% among HIV- women. Women below 25 years had higher HRHPV prevalence. HPV prevalence was higher in women with higher parity. Higher HRHPV prevalence in younger women attributed to early sexual debut. The higher prevalence of HRHPV in HIV+ women was as a consequence of depressed immunity and greater exposure to risk factorsConclusion: HIV+ women are more infected with HRHPV than their HIV- counterparts. Immune system related factors which affect the interpretation of screening tests like VIA require further investigation especially in immune compromised individuals

Overexpression of connexin 43 using a retroviral vector improves electrical coupling of skeletal myoblasts with cardiac myocytes in vitro.

BACKGROUND: Organ transplantation is presently often the only available option to repair a damaged heart. As heart donors are scarce, engineering of cardiac grafts from autologous skeletal myoblasts is a promising novel therapeutic strategy. The functionality of skeletal muscle cells in the heart milieu is, however, limited because of their inability to integrate electrically and mechanically into the myocardium. Therefore, in pursuit of improved cardiac integration of skeletal muscle grafts we sought to modify primary skeletal myoblasts by overexpression of the main gap-junctional protein connexin 43 and to study electrical coupling of connexin 43 overexpressing myoblasts to cardiac myocytes in vitro. METHODS: To create an efficient means for overexpression of connexin 43 in skeletal myoblasts we constructed a bicistronic retroviral vector MLV-CX43-EGFP expressing the human connexin 43 cDNA and the marker EGFP gene. This vector was employed to transduce primary rat skeletal myoblasts in optimised conditions involving a concomitant use of the retrovirus immobilising protein RetroNectin and the polycation transduction enhancer Transfectam. The EGFP-positive transduced cells were then enriched by flow cytometry. RESULTS: More than four-fold overexpression of connexin 43 in the transduced skeletal myoblasts, compared with non-transduced cells, was shown by Western blotting. Functionality of the overexpressed connexin 43 was demonstrated by microinjection of a fluorescent dye showing enhanced gap-junctional intercellular transfer in connexin 43 transduced myoblasts compared with transfer in non-transduced myoblasts. Rat cardiac myocytes were cultured in multielectrode array culture dishes together with connexin 43/EGFP transduced skeletal myoblasts, control non-transduced skeletal myoblasts or alone. Extracellular field action potential activation rates in the co-cultures of connexin 43 transduced skeletal myoblasts with cardiac myocytes were significantly higher than in the co-cultures of non-transduced skeletal myoblasts with cardiac myocytes and similar to the rates in pure cultures of cardiac myocytes. CONCLUSION: The observed elevated field action potential activation rate in the co-cultures of cardiac myocytes with connexin 43 transduced skeletal myoblasts indicates enhanced cell-to-cell electrical coupling due to overexpression of connexin 43 in skeletal myoblasts. This study suggests that retroviral connexin 43 transduction can be employed to augment engineering of the electrocompetent cardiac grafts from patients own skeletal myoblasts