11,942 research outputs found

    Inactivation of Plasmodium falciparum in whole blood by riboflavin plus irradiation.

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    BACKGROUND: Malaria parasites are frequently transmitted by unscreened blood transfusions in Africa. Pathogen reduction methods in whole blood would thus greatly improve blood safety. We aimed to determine the efficacy of riboflavin plus irradiation for treatment of whole blood infected with Plasmodium falciparum. STUDY DESIGN AND METHODS: Blood was inoculated with 10(4) or 10(5) parasites/mL and riboflavin treated with or without ultraviolet (UV) irradiation (40-160 J/mL red blood cells [mL(RBCs)]). Parasite genome integrity was assessed by quantitative amplification inhibition assays, and P. falciparum viability was monitored in vitro. RESULTS: Riboflavin alone did not affect parasite genome integrity or parasite viability. Application of UV after riboflavin treatment disrupted parasite genome integrity, reducing polymerase-dependent amplification by up to 2 logs (99%). At 80 J/mL(RBCs), riboflavin plus irradiation prevented recovery of viable parasites in vitro for 2 weeks, whereas untreated controls typically recovered to approximately 2% parasitemia after 4 days of in vitro culture. Exposure of blood to 160 J/mL(RBCs) was not associated with significant hemolysis. CONCLUSIONS: Riboflavin plus irradiation treatment of whole blood damages parasite genomes and drastically reduces P. falciparum viability in vitro. In the absence of suitable malaria screening assays, parasite inactivation should be investigated for prevention of transfusion-transmitted malaria in highly endemic areas

    A Relationship between Supermassive Black Hole Mass and the Total Gravitational Mass of the Host Galaxy

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    We investigate the correlation between the mass of a central supermassive black hole and the total gravitational mass of the host galaxy (M_tot). The results are based on 43 galaxy-scale strong gravitational lenses from the Sloan Lens ACS (SLACS) Survey whose black hole masses were estimated through two scaling relations: the relation between black hole mass and Sersic index (M_bh - n) and the relation between black hole mass and stellar velocity dispersion (M_bh - sigma). We use the enclosed mass within R_200, the radius within which the density profile of the early type galaxy exceeds the critical density of the Universe by a factor of 200, determined by gravitational lens models fitted to HST imaging data, as a tracer of the total gravitational mass. The best fit correlation, where M_bh is determined from M_bh - sigma relation, is log(M_bh) = (8.18 +/- 0.11) + (1.55 +/- 0.31) (log(M_tot) - 13.0) over 2 orders of magnitude in M_bh. From a variety of tests, we find that we cannot reliably infer a connection between M_bh and M_tot from the M_bh - n relation. The M_bh - M_tot relation provides some of the first, direct observational evidence to test the prediction that supermassive black hole properties are determined by the halo properties of the host galaxy.Comment: 29 pages, 10 figures, Accepted for publication in Ap

    Preoperative neutrophil-lymphocyte ratio and outcome from coronary artery bypass grafting

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    Background: An elevated preoperative white blood cell count has been associated with a worse outcome after coronary artery bypass grafting (CABG). Leukocyte subtypes, and particularly the neutrophil-lymphocyte (N/L) ratio, may however, convey superior prognostic information. We hypothesized that the N/L ratio would predict the outcome of patients undergoing surgical revascularization. Methods: Baseline clinical details were obtained prospectively in 1938 patients undergoing CABG. The differential leukocyte was measured before surgery, and patients were followed-up 3.6 years later. The primary end point was all-cause mortality. Results: The preoperative N/L ratio was a powerful univariable predictor of mortality (hazard ratio [HR] 1.13 per unit, P 3.36). Conclusion: An elevated N/L ratio is associated with a poorer survival after CABG. This prognostic utility is independent of other recognized risk factors.Peer reviewedAuthor versio

    Evaluation of a mass distribution programme for fine-mesh impregnated bednets against visceral leishmaniasis in eastern Sudan.

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    During an epidemic of visceral leishmaniasis (VL) in eastern Sudan, Médecins Sans Frontières distributed 357,000 insecticide-treated bednets (ITN) to 155 affected villages between May 1999 and March 2001. To estimate the protective effect of the ITN, we evaluated coverage and use of ITN, and analysed VL incidence by village from March 1996 to June 2002. We provided ITN to 94% of the individuals >5 years old. Two years later, 44% (95% CI 39-48%) of nets were reasonably intact. Because ITN were mainly used as protection against nuisance mosquitoes, bednet use during the VL transmission season ranged from <10% during the hot dry months to 55% during the beginning of the rainy season. ITN were put up from 9 to 11 p.m., leaving children unprotected during a significant period of sandfly-biting hours after sunset. Regression analysis of incidence data from 114 villages demonstrated a significant reduction of VL by village and month following ITN provision. The greatest effect was 17-20 months post-intervention, with VL cases reduced by 59% (95% CI: 25-78%). An estimated 1060 VL cases were prevented between June 1999 and January 2001, a mean protective effect of 27%. Although results need to be interpreted with caution, this analysis indicates a potentially strong reduction in VL incidence following a community distribution of ITN. The effectiveness of ITN depends on behavioural factors, which differ between communities

    Self-Similar Dynamical Relaxation of Dark Matter Halos in an Expanding Universe

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    We investigate the structure of cold dark matter halos using advanced models of spherical collapse and accretion in an expanding Universe. These base on solving time-dependent equations for the moments of the phase-space distribution function in the fluid approximation; our approach includes non-radial random motions, and most importantly, an advanced treatment of both dynamical relaxation effects that takes place in the infalling matter: phase-mixing associated to shell crossing, and collective collisions related to physical clumpiness. We find self-similar solutions for the spherically-averaged profiles of mass density rho(r), pseudo phase-space density Q(r) and anisotropy parameter beta(r). These profiles agree with the outcomes of state-of-the-art N-body simulations in the radial range currently probed by the latter; at smaller radii, we provide specific predictions. In the perspective provided by our self-similar solutions we link the halo structure to its two-stage growth history, and propose the following picture. During the early fast collapse of the inner region dominated by a few merging clumps, efficient dynamical relaxation plays a key role in producing a closely universal mass density and pseudo phase-space density profiles; in particular, these are found to depend only weakly on the detailed shape of the initial perturbation and the related collapse times. The subsequent inside-out growth of the outer regions feeds on the slow accretion of many small clumps and diffuse matter; thus the outskirts are only mildly affected by dynamical relaxation but are more sensitive to asymmetries and cosmological variance.Comment: 31 pages, 16 figures. Typos corrected. Accepted by Ap

    A remembrance of things (best) forgotten: The 'allegorical past' and the feminist imagination

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    This is the author's PDF version of an article published in Feminist theology© 2012. The definitive version is available at http://fth.sagepub.com/This article discusses the US TV series Mad Men, which is set in an advertising agency in 1960s New York, in relation to two key elements which seem significant for a consideration of the current state of feminism in church and academy, both of which centre around what it means to remember or (not) to forget

    Two new species of entobdelline skin parasites (Monogenea, Capsalidae) from the blotched fantail ray, Taeniura meyeni, in the Pacific Ocean, with comments on spermatophores and the male copulatory apparatus

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    We made a comparative anatomical study of entobdelline monogenean skin parasites from the blotched fantail ray, Taeniura meyeni (= T. melanospila) from public aquaria and fish-holding facilities distributed widely across the western Pacific Ocean. These facilities were located in Australia (Mooloolaba, southern Queensland; Cairns, northern Queensland), Taiwan and Japan. The capture localities of the aquarium fishes are unknown to us, with the exception of the individual fish from northern Queensland which came from Sudbury Reef, a local inshore reef. Entobdellines from southern Queensland differed morphologically from those from northern Queensland and Taiwan and the 2 new monogenean species are described and named Neoentobdella garneri sp. nov. and N. taiwanensis sp. nov., respectively. We determined that an entobdelline collected by Dyer and co-workers from a ray identified as T. melanospila (= T. meyeni) from an aquarium in Okinawa, Japan and identified by them as Entobdella squamula (Heath, 1902) Johnston, 1929 was misidentified and is tentatively assigned to N. taiwanensis sp. nov. The male copulatory organ of each new species resembles a penis, but evidence that these organs are eversible like a cirrus is presented. Caution is advised in deciding whether the male copulatory organs of capsalids may function as a penis or as a cirrus and we suggest that possession of a penis versus a cirrus may not necessarily indicate wide evolutionary divergence. In N. garneri, spermatophores consist of a sausage-shaped capsule and a long hollow stalk. A spermatophore received from a donor is anchored in the vagina by means of the stalk, with the capsule protruding outside the body

    Development of dilated cardiomyopathy and impaired calcium homeostasis with cardiac-specific deletion of ESRRβ.

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    Mechanisms underlying the development of idiopathic dilated cardiomyopathy (DCM) remain poorly understood. Using transcription factor expression profiling, we identified estrogen-related receptor-β (ESRRβ), a member of the nuclear receptor family of transcription factors, as highly expressed in murine hearts and other highly oxidative striated muscle beds. Mice bearing cardiac-specific deletion of ESRRβ (MHC-ERRB KO) develop DCM and sudden death at ~10 mo of age. Isolated adult cardiomyocytes from the MHC-ERRB KO mice showed an increase in calcium sensitivity and impaired cardiomyocyte contractility, which preceded echocardiographic cardiac remodeling and dysfunction by several months. Histological analyses of myocardial biopsies from patients with various cardiomyopathies revealed that ESRRβ protein is absent from the nucleus of cardiomyocytes from patients with DCM but not other forms of cardiomyopathy (ischemic, hypertrophic, and arrhythmogenic right ventricular cardiomyopathy). Taken together these observations suggest that ESRRβ is a critical component in the onset of DCM by affecting contractility and calcium balance.NEW & NOTEWORTHY Estrogen-related receptor-β (ESRRβ) is highly expressed in the heart and cardiac-specific deletion results in the development of a dilated cardiomyopathy (DCM). ESRRβ is mislocalized in human myocardium samples with DCM, suggesting a possible role for ESRRβ in the pathogenesis of DCM in humans

    Cosmological Simulations of Massive Compact High-z Galaxies

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    In order to investigate the structure and dynamics of the recently discovered massive (M_* > 10^11 M_sun) compact z~2 galaxies, cosmological hydrodynamical/N-body simulations of a proto-cluster region have been undertaken. At z=2, the highest resolution simulation contains ~5800 resolved galaxies, of which 509, 27 and 5 have M_* > 10^10 M_sun, > 10^11 M_sun and > 4x10^11 M_sun, respectively. Effective radii and characteristic stellar densities have been determined for all galaxies. At z=2, for the definitely well resolved mass range of M_* > 10^11 Msun, the mass-size relation is consistent with observational findings for the most compact z~2 galaxies. The very high velocity dispersion recently measured for a compact z~2 galaxy (~510 km/s; van Dokkum et al 2009) can be matched at about the 1-sigma level, although a somewhat larger mass than the estimated M_* ~ 2 x 10^11 M_sun is indicated. For the above mass range, the galaxies have an average axial ratio = 0.64 +/- 0.02 with a dispersion of 0.1, an average rotation to 1D velocity dispersion ratio = 0.46 +/- 0.06 with a dispersion of 0.3, and a maximum value of v/sigma ~ 1.1. Rotation and velocity anisotropy both contribute in flattening the compact galaxies. Some of the observed compact galaxies appear flatter than any of the simulated galaxies. Finally, it is found that the massive compact galaxies are strongly baryon dominated in their inner parts, with typical dark matter mass fractions of order only 20% inside of r=2R_eff.Comment: 10 pages, 8 figures, submitted to Ap
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