42 research outputs found

    Modelling CO formation in the turbulent interstellar medium

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    We present results from high-resolution three-dimensional simulations of turbulent interstellar gas that self-consistently follow its coupled thermal, chemical and dynamical evolution, with a particular focus on the formation and destruction of H2 and CO. We quantify the formation timescales for H2 and CO in physical conditions corresponding to those found in nearby giant molecular clouds, and show that both species form rapidly, with chemical timescales that are comparable to the dynamical timescale of the gas. We also investigate the spatial distributions of H2 and CO, and how they relate to the underlying gas distribution. We show that H2 is a good tracer of the gas distribution, but that the relationship between CO abundance and gas density is more complex. The CO abundance is not well-correlated with either the gas number density n or the visual extinction A_V: both have a large influence on the CO abundance, but the inhomogeneous nature of the density field produced by the turbulence means that n and A_V are only poorly correlated. There is a large scatter in A_V, and hence CO abundance, for gas with any particular density, and similarly a large scatter in density and CO abundance for gas with any particular visual extinction. This will have important consequences for the interpretation of the CO emission observed from real molecular clouds. Finally, we also examine the temperature structure of the simulated gas. We show that the molecular gas is not isothermal. Most of it has a temperature in the range of 10--20 K, but there is also a significant fraction of warmer gas, located in low-extinction regions where photoelectric heating remains effective.Comment: 37 pages, 15 figures; minor revisions, matches version accepted by MNRA

    Thalidomide, dexamethasone and lovastatin with autologous stem cell transplantation as a salvage immunomodulatory therapy in patients with relapsed and refractory multiple myeloma

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    The treatment of patients with multiple myeloma usually includes many drugs including thalidomide, lenalidomide and bortezomib. Lovastatin and other inhibitors of HMG-CoA reductase demonstrated to exhibit antineoplasmatic and proapoptotic properties in numerous in vitro studies involving myeloma cell lines. We treated 91 patients with relapsed or refractory multiple myeloma with thalidomide, dexamethasone and lovastatin (TDL group, 49 patients) or thalidomide and dexamethasone (TD group, 42 patients). A clinical response defined of at least 50% reduction of monoclonal band has been observed in 32% of TD patients and 44% of TDL patients. Prolongation of overall survival and progression-free survival in the TDL group as compared with the TD group has been documented. The TDL regimen was safe and well tolerated. The incidence of side effects was comparable in both groups. Plasma cells have been cultured in vitro with thalidomide and lovastatin to assess the impact of both drugs on the apoptosis rate of plasma cells. In vitro experiments revealed that the combination of thalidomide and lovastatin induced higher apoptosis rate than apoptosis induced by each drug alone. Our results suggest that the addition of lovastatin to the TD regimen may improve the response rate in patients with relapsed or refractory myeloma

    Bisphosphonates as antimyeloma drugs

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    In patients with symptomatic multiple myeloma (MM), bisphosphonate (BP) treatment has been widely used to prevent bone loss and preserve skeletal health because of its proven effects on inhibiting osteoclast-mediated bone resorption. In addition to their effects on osteoclasts, it is becoming increasingly evident that BPs may have additional effects on the bone microenvironment and cells other than osteoclasts that may potentially inhibit the development and progression of MM. This review focuses on the pathophysiology of MM with an emphasis on the events that drive MM progression within the bone and the mechanisms by which BPs may inhibit specific processes. The underlying molecular mechanisms that drive the modulation of cellular fate and function and consequent physiological outcomes are described. Direct effects on myeloma cell growth and survival and the interactions between myeloma cells and the bone microenvironment are discussed. Clinical evidence of the antimyeloma effects of BPs is emerging and is also reviewed

    Heavy genealogy: mapping the currents, contraflows and conflicts of the emergent field of metal studies, 1978-2010

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    What is metal studies? How can we define and characterize it? How has it emerged as a body of academic enquiry? What are its dominant disciplinary strands, theoretical concepts and preferred methodologies? Which studies have claimed most attention, defined the goals of scholarship, typical research strategies and values? How has the claim for the legitimacy or symbolic value of metal scholarship been achieved (if it has): over time and through gradual acceptance or through conflict and contestation? How can this process of formation, or strategy of legitimation, be mapped, examined and interrogated and which methods of historical, institutional and cultural analysis are best suited to this task? Working with the most complete bibliography to date of published research on heavy metal, music and culture (the MSBD), this article employs Foucault’s archaeological “method” to examine the institutional, cultural and political contexts and conflicts that inform the genealogy of this scholarship. Such analysis reveals a formative, largely negative account of heavy metal to be found in the “sociology of rock”; a large volume of psychology work, examining heavy metal music preference as an indicator of youth risk, deviance and delinquency; sociological work on youth and deviancy critical of the values of this research and its links to social policy and politics; culminating in the work of Weinstein and Walser, who advocate a perspective sympathetic to the values of heavy metal fans themselves. Following Bourdieu, I interpret such symbolic strategies as claims for expertise within the academic field that are high or low in symbolic capital to the extent they can attain disciplinary autonomy. I then go on to examine the most recent strands of research, within cultural studies and ethnomusicology, concerned with the global metal music diaspora, and consider to what extent such work is constitutive of a coherent subfield of metal studies that can be distinguished from earlier work and what the implications of this might be

    The matrix protein of Human respiratory syncytial virus localises to the nucleus of infected cells and inhibits transcription

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    We studied the kinetics of localisation of matrix (M) protein of Human respiratory syncytial virus (RSV) in infected cells. M protein was detected in the nucleus early in infection, by confocal microscopy and by immunoblotting of nuclear fractions. We next tested the possibility that M protein may be involved in inhibition of host cell transcription. Nuclear extracts from RSV infected cells had less transcriptional activity in vitro when compared to nuclear extracts from mock infected cells. In addition, nuclear extracts from RSV infected cells inhibited the transcriptional activity of nuclear extracts from mock infected cells, suggesting that an inhibitory activity was transferred with nuclear extracts from RSV infected cells. Our data suggest that M protein may play a role early in the infection by inhibiting host cell transcription.</p
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