3,889 research outputs found

    The extraordinary mid-infrared spectral properties of FeLoBAL Quasars

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    We present mid-infrared spectra of six FeLoBAL QSOs at 1<z<1.8, taken with the Spitzer space telescope. The spectra span a range of shapes, from hot dust dominated AGN with silicate emission at 9.7 microns, to moderately obscured starbursts with strong Polycyclic Aromatic Hydrocarbon (PAH) emission. The spectrum of one object, SDSS 1214-0001, shows the most prominent PAHs yet seen in any QSO at any redshift, implying that the starburst dominates the mid-IR emission with an associated star formation rate of order 2700 solar masses per year. With the caveats that our sample is small and not robustly selected, we combine our mid-IR spectral diagnostics with previous observations to propose that FeLoBAL QSOs are at least largely comprised of systems in which (a) a merger driven starburst is ending, (b) a luminous AGN is in the last stages of burning through its surrounding dust, and (c) which we may be viewing over a restricted line of sight range.Comment: ApJ, accepte

    CoSMoMVPA: Multi-Modal Multivariate Pattern Analysis of Neuroimaging Data in Matlab/GNU Octave

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    Recent years have seen an increase in the popularity of multivariate pattern (MVP) analysis of functional magnetic resonance (fMRI) data, and, to a much lesser extent, magneto- and electro-encephalography (M/EEG) data. We present CoSMoMVPA, a lightweight MVPA (MVP analysis) toolbox implemented in the intersection of the Matlab and GNU Octave languages, that treats both fMRI and M/EEG data as first-class citizens. CoSMoMVPA supports all state-of-the-art MVP analysis techniques, including searchlight analyses, classification, correlations, representational similarity analysis, and the time generalization method. These can be used to address both data-driven and hypothesis-driven questions about neural organization and representations, both within and across: space, time, frequency bands, neuroimaging modalities, individuals, and species. It uses a uniform data representation of fMRI data in the volume or on the surface, and of M/EEG data at the sensor and source level. Through various external toolboxes, it directly supports reading and writing a variety of fMRI and M/EEG neuroimaging formats, and, where applicable, can convert between them. As a result, it can be integrated readily in existing pipelines and used with existing preprocessed datasets. CoSMoMVPA overloads the traditional volumetric searchlight concept to support neighborhoods for M/EEG and surface-based fMRI data, which supports localization of multivariate effects of interest across space, time, and frequency dimensions. CoSMoMVPA also provides a generalized approach to multiple comparison correction across these dimensions using Threshold-Free Cluster Enhancement with state-of-the-art clustering and permutation techniques. CoSMoMVPA is highly modular and uses abstractions to provide a uniform interface for a variety of MVP measures. Typical analyses require a few lines of code, making it accessible to beginner users. At the same time, expert programmers can easily extend its functionality. CoSMoMVPA comes with extensive documentation, including a variety of runnable demonstration scripts and analysis exercises (with example data and solutions). It uses best software engineering practices including version control, distributed development, an automated test suite, and continuous integration testing. It can be used with the proprietary Matlab and the free GNU Octave software, and it complies with open source distribution platforms such as NeuroDebian. CoSMoMVPA is Free/Open Source Software under the permissive MIT license. Website: http://cosmomvpa.org Source code: https://github.com/CoSMoMVPA/CoSMoMVPA

    An Evolutionary Paradigm for Dusty Active Galaxies at Low Redshift

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    We apply methods from Bayesian inferencing and graph theory to a dataset of 102 mid-infrared spectra, and archival data from the optical to the millimeter, to construct an evolutionary paradigm for z<0.4 infrared-luminous galaxies (ULIRGs). We propose that the ULIRG lifecycle consists of three phases. The first phase lasts from the initial encounter until approximately coalescence. It is characterized by homogeneous mid-IR spectral shapes, and IR emission mainly from star formation, with a contribution from an AGN in some cases. At the end of this phase, a ULIRG enters one of two evolutionary paths depending on the dynamics of the merger, the available quantities of gas, and the masses of the black holes in the progenitors. On one branch, the contributions from the starburst and the AGN to the total IR luminosity decline and increase respectively. The IR spectral shapes are heterogeneous, likely due to feedback from AGN-driven winds. Some objects go through a brief QSO phase at the end. On the other branch, the decline of the starburst relative to the AGN is less pronounced, and few or no objects go through a QSO phase. We show that the 11.2 micron PAH feature is a remarkably good diagnostic of evolutionary phase, and identify six ULIRGs that may be archetypes of key stages in this lifecycle.Comment: ApJ accepted. Comments welcome. We suggest reading section 2 before looking at the figures. 26 pages, 21 figures, 1 tabl

    When should a mechanical tricuspid valve replacement be considered?

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    BackgroundIsolated mechanical tricuspid valve replacement (mTVR) is uncommon, early mortality is reported to be high, and little is known regarding the long-term outcome. We sought to evaluate the long-term outcome of mTVR.MethodsFrom 1980 to 2007, isolated mTVR was performed in 64 patients (33 men) at our institution; the median age was 45.5 years (6-71 years). There were 2192 tricuspid valve (TV) repairs and 137 isolated bioprosthetic TV replacements during the same time interval. Valve dysfunction was caused by congenital TV abnormality in 45 patients (70%), carcinoid heart disease in 13 (20%), traumatic TV regurgitation in 3 (5%), and other reason in 3 (5%). Twenty-three patients (36%) had at least 1 previous cardiac procedure (TV repair in 8 and bioprosthetic TV replacement in 7).ResultsMechanical prostheses used included Starr-Edwards (before 1993) in 36 patients (56%) and bileaflet prostheses in 28 (44%). Concomitant procedures included atrial septal defect closure in 28 (44%), arrhythmia surgery in 11 (17%), and pulmonary valvectomy for carcinoid disease in 10 patients (16%). Early mortality occurred in 5 patients (7.8%). Early morbidity included a permanent pacemaker in 9 (14%) and reexploration for bleeding in 2 patients (3%). Mean follow-up was 6 years (maximum 22.4 years). Five- and 10-year survival was 65% and 58%, respectively. There was no valve-related mortality. Late morbidity included valve thrombosis in 5 patients (8%); 3 were managed nonoperatively and 2 underwent TV rereplacement.ConclusionsIsolated mTVR still leads to increased early mortality. A mechanical valve can be considered in select situations when anticoagulation is necessary and in the presence of good right ventricular function

    A Unique Amphibole- and Magnetite-Rich Carbonaceous Chondrite from Almahata Sitta

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    Almahata Sitta (AhS) 202 from the UoK collection represents a clast from the polymict breccia asteroid 2008 TC3. AhS 202 was recognized as a unique carbonaceous chondrite (CC) with a high magnetite content. Here we report that it also contains a significant amount of amphibole, a mineral that is very rare in chondrites and has not previously been reported in significant abundance in a CC. We present new petrographic, oxygen isotope, and micro-FTIR data. We discuss petrogenesis and possible relationships to known CC

    A New Determination of the High Redshift Type Ia Supernova Rates with the Hubble Space Telescope Advanced Camera for Surveys

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    We present a new measurement of the volumetric rate of Type Ia supernova up to a redshift of 1.7, using the Hubble Space Telescope (HST) GOODS data combined with an additional HST dataset covering the North GOODS field collected in 2004. We employ a novel technique that does not require spectroscopic data for identifying Type Ia supernovae (although spectroscopic measurements of redshifts are used for over half the sample); instead we employ a Bayesian approach using only photometric data to calculate the probability that an object is a Type Ia supernova. This Bayesian technique can easily be modified to incorporate improved priors on supernova properties, and it is well-suited for future high-statistics supernovae searches in which spectroscopic follow up of all candidates will be impractical. Here, the method is validated on both ground- and space-based supernova data having some spectroscopic follow up. We combine our volumetric rate measurements with low redshift supernova data, and fit to a number of possible models for the evolution of the Type Ia supernova rate as a function of redshift. The data do not distinguish between a flat rate at redshift > 0.5 and a previously proposed model, in which the Type Ia rate peaks at redshift >1 due to a significant delay from star-formation to the supernova explosion. Except for the highest redshifts, where the signal to noise ratio is generally too low to apply this technique, this approach yields smaller or comparable uncertainties than previous work.Comment: Accepted for publication in Ap

    Septin 9 isoforms promote tumorigenesis in mammary epithelial cells by increasing migration and ECM degradation through metalloproteinase secretion at focal adhesions

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    © 2019, The Author(s), under exclusive licence to Springer Nature Limited. The cytoskeletal interacting protein Septin 9 (SEPT9), a member of the septin gene family, has been proposed to have oncogenic functions. It is a known hot spot of retroviral tagging insertion and a fusion partner of both de novo and therapy-induced mixed lineage leukemia (MLL). Of all septins, SEPT9 holds the strongest link to cancer, especially breast cancer. Murine models of breast cancer frequently exhibit SEPT9 amplification in the form of double minute chromosomes, and about 20% of human breast cancer display genomic amplification and protein over expression at the SEPT9 locus. Yet, a clear mechanism by which SEPT9 elicits tumor-promoting functions is lacking. To obtain unbiased insights on molecular signatures of SEPT9 upregulation in breast tumors, we overexpressed several of its isoforms in breast cancer cell lines. Global transcriptomic profiling supports a role of SEPT9 in invasion. Functional studies reveal that SEPT9 upregulation is sufficient to increase degradation of the extracellular matrix, while SEPT9 downregulation inhibits this process. The degradation pattern is peripheral and associated with focal adhesions (FAs), where it is coupled with increased expression of matrix metalloproteinases (MMPs). SEPT9 overexpression induces MMP upregulation in human tumors and in culture models and promotes MMP3 secretion to the media at FAs. Downregulation of SEPT9 or chemical inhibition of septin filament assembly impairs recruitment of MMP3 to FAs. Our results indicate that SEPT9 promotes upregulation and both trafficking and secretion of MMPs near FAs, thus enhancing migration and invasion of breast cancer cells

    Transient Myocardial Thickening in Cats Associated with Heart Failure.

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    BACKGROUND: Cats with hypertrophic cardiomyopathy (HCM) and congestive heart failure (CHF) can have resolution of both left ventricular hypertrophy and CHF. OBJECTIVES: To describe the clinical characteristics of cats with transient myocardial thickening (TMT) and CHF compared with a control population of cats without resolution of HCM. ANIMALS: A total of 21 cats with TMT, 21 cats with HCM. METHODS: Retrospective study. Clinical records at 4 veterinary centers were searched for TMT cases and a control group of cats with HCM and CHF. TMT was defined as initial maximal left ventricular wall thickness (LVWT) ≄6 mm with left-sided CHF, with subsequent resolution of CHF, reduction in left atrium/aorta (LA/Ao), and LVWT<5.5 mm. HCM was defined as persistent LVWT ≄6 mm. RESULTS: Cats with TMT were younger (2 [0.4-11.4] years) than cats with HCM (8 [1.6-14] years) (P < 0.0001), and antecedent events were more common (15/21 versus 6/21, respectively) (P = 0.01). In cats with TMT, LVWT normalized from 6.8 [6.0-9.7] mm to 4.8 [2.8-5.3] mm and LA/Ao decreased from 1.8 [1.6-2.3] to 1.45 [1.2-1.7] after a mean interval of 3.3 (95% CI: 1.8-4.7) months. CHF recurred in 1 of 21 TMT and 15 of 21 cats with HCM. Cardiac treatment was discontinued in 20 of 21 cats with TMT and 0 of 21 HCM cats. All cats with TMT survived, whereas 8 of 19 cats with HCM died during the study period. CONCLUSIONS AND CLINICAL IMPORTANCE: TMT occurs in younger cats, and antecedent events are common. The prognosis is better in cats with CHF associated with TMT than HCM

    Rethinking globalised resistance : feminist activism and critical theorising in international relations

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    This article argues that a feminist approach to the 'politics of resistance' offers a number of important empirical insights which, in turn, open up lines of theoretical inquiry which critical theorists in IR would do well to explore. Concretely, we draw on our ongoing research into feminist 'anti-globalisation' activism to rethink the nature of the subject of the politics of resistance, the conditions under which resistance emerges and how resistance is enacted and expressed. We begin by discussing the relationship of feminism to critical IR theory as a way of situating and explaining the focus and approach of our research project. We then summarise our key empirical arguments regarding the emergence, structure, beliefs, identities and practices of feminist 'anti-globalisation' activism before exploring the implications of these for a renewed critical theoretical agenda in IR
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