5,514 research outputs found

    Introducing passive matched field acoustic tomography

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    In acoustic tomography sea-basin environmental parameters such as temperature profiles and current-velocities are derived, when ray propagation models are adopted, by the travel time estimates relative to the identifiable ray paths. The transmitted signals are either single frequency, or impulsive, or intermittent and deterministic. When the wavelength is comparable with the scale lengths present in the propagation scenario, Matched Field Tomography (MFT) is used, entailing the consideration of waveguide modes instead of rays. A new concept in tomography is introduced in the paper, that employs passively the noise emitted by ships of opportunity (cargoes, ferries) as source signals. The passive technique is acoustic-pollution-free, and if a basin is selected in which a regular ship traffic occurs data can be received on a regular schedule, with no transmission cost. A novel array pre-processor for passive tomography is introduced, such that the signal structure at the pre-processor output is nearly the same as that obtainable in the case of single-frequency source signals. Hence, at the pre-processor output all the tomographic inversion methods valid for active tomography employing single-frequency sources can be applied. The differences between active and passive tomography are pointed out and the potential of passive techniques is illustrated by simple propagation scenarios adopting either rays or waveguide modes

    A Bourdieusian Analysis of Intersectionality In Ontario’s Community College System

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    The main focus of my dissertation is a detailed investigation of how gender and race intersect in the Province’s community college administrations thereby creating marginalized and oppressive social structures. My original contribution to knowledge addresses the daily lived experiences of gender performativity, white patriarchy and racial discrimination in the managerial sector of the Ontario college system. The theoretical foundation is based upon the work of Pierre Bourdieu and the scholarship of several prominent feminist theorists, including Kate Huppatz, Lois McNay, Patricia Hill Collins and Judith Butler. Each of them critically expands upon Bourdieu’s concepts to focus on intersectional inequality, specific examples of which are found in the Province’s college middle management sector. This thesis deploys feminist Bourdieusian concepts, such as social and gender capital, to highlight gender and racial power in the matrix of symbolic domination that is situated in the Province’s colleges. It also directs attention to social practices of self empowerment to counter and resist the negative aspects of gender capital and racial hegemony. The mutually constitutive social dimensions of the college bureaucracy have never been the topic of such detailed and extensive research. No prior, published investigations exist that examine the Provincial community college system over issues related to whether and how individuals utilize gender capital to negotiate hierarchical positionality or contend with intersectional disadvantage. My findings document a systemically gendered and racialized work environment. Some middle managers purport to advance their careers by dominating others in the workplace. However, in response, there are others who demonstrate a form of proactive resistance to what they characterize as discriminatory institutional regimes of neoliberal patriarchy and white privilege. They do so through strategic practices designed to navigate the hidden, intersubjective contours and oppressive consequences of gender and racial inequality. My findings illustrate the broad social dimensions of these behaviours and the manner in which they are played out in the social field of Ontario’s community college system. Using a sequential, mixed methods approach to data acquisition, my work focuses on whether agents experience networks of power differently because of the impact of systemic inequality and how they choose to respond to resulting workplace marginalization. I argue that organizationally ensconced diversity policies fail to neutralize the intersectional struggles that are endlessly reproduced in dominant workplace social networks. “One-size-fits-all” policies, even with the imprimatur of law, fail to rout and neuter historical influences of white privilege and patriarchy. This failure negatively impacts subjective identities in the complex relationship between the individual, and the objective structure comprising the middle management field of practice. The findings of this study demonstrate how inequalities are sustained and reproduced cogeneratively because of unremedied gender and racial discrimination in the Province’s community colleges. My study brings to light an awareness of these intersecting oppressions and illuminates the implicit deficiencies of the institutional diversity rhetoric in Ontario. Ultimately, it brings into sharper focus the lived experiences of social inequity amid the naturalization of patriarchy and white privilege

    Passive ocean acoustic tomography: theory and experiment

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    In this paper the Passive Ocean Acoustic Tomography (P-OAT) methodology is presented. This technique, avoiding the use of a dedicated active sound source, estimates the sea water temperature spatial distribution from the received noise emitted from ships of opportunity. The feasibility of the proposed methodology has been confirmed both by test-runs on semi-synthetic data and by the use of real acoustic and environmental data collected during INTIMATE00 experiment performed on October 2000 in the Atlantic Ocean off the Portuguese coasts

    LTF and DEFB1 polymorphisms are associated with susceptibility toward chronic periodontitis development

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    Objectives: Chronic periodontitis is a common pathological condition that affects the supporting tissue of the teeth, leading to progressive alveolar bone destruction and teeth loss. The disease is caused by bacteria and derives from an altered host immune and inflammatory response, also involving different factors such as the oral hygiene, smoking, and genetic background. The innate immune response, the first line of host defense, could also play an important role in the susceptibility to chronic periodontitis. In this study, we evaluated the possible association between periodontal disease and seven genetic variations within DEFB1 and LTF genes, encoding for \u3b2-defensins 1 and lactoferrin (two members of oral innate immune system), in an Italian isolated population. Subjects and Methods: DEFB1 5\u2032UTR g. -52G>A (rs1799946), g. -44C>G (rs1800972), g. -20G>A (rs11362), 3\u2032UTR c*5G>A (rs1047031), c*87A>G (rs1800971), LTF p.Ala29Thr (rs1126477), and p.Lys47Arg (rs1126478) single nucleotide polymor- phisms (SNPs) were analyzed in 155 healthy individuals and 439 chronic periodontitis patients from North-East Italy. Results: Significant associations were found between periodontitis and g. -20G>A (rs11362) and g. -44C>G (rs1800972) SNPs in DEFB1 gene as well as p.Ala29Thr (rs1126477) and p.Lys47Arg (rs1126478) SNPs in LTF gene. Discussion: Our results suggest the involvement of DEFB1 and LTF genetic variations in the susceptibility toward development of periodontitis

    Label-free imaging flow cytometry for analysis and sorting of enzymatically dissociated tissues

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    Biomedical research relies on identification and isolation of specific cell types using molecular biomarkers and sorting methods such as fluorescence or magnetic activated cell sorting. Labelling processes potentially alter the cells’ properties and should be avoided, especially when purifying cells for clinical applications. A promising alternative is the label-free identification of cells based on physical properties. Sorting real-time deformability cytometry (soRT-DC) is a microfluidic technique for label-free analysis and sorting of single cells. In soRT-FDC, bright-field images of cells are analyzed by a deep neural net (DNN) to obtain a sorting decision, but sorting was so far only demonstrated for blood cells which show clear morphological differences and are naturally in suspension. Most cells, however, grow in tissues, requiring dissociation before cell sorting which is associated with challenges including changes in morphology, or presence of aggregates. Here, we introduce methods to improve robustness of analysis and sorting of single cells from nervous tissue and provide DNNs which can distinguish visually similar cells. We employ the DNN for image-based sorting to enrich photoreceptor cells from dissociated retina for transplantation into the mouse eye

    Gravitational Wave Bursts from Cosmic Superstring Reconnections

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    We compute the gravitational waveform produced by cosmic superstring reconnections. This is done by first constructing the superstring reconnection trajectory, which closely resembles that of classical, instantaneous reconnection but with the singularities smoothed out due to the string path integral. We then evaluate the graviton vertex operator in this background to obtain the burst amplitude. The result is compared to the detection threshold for current and future gravitational wave detectors, finding that neither bursts nor the stochastic background would be detectable by Advanced LIGO. This disappointing but anticipated conclusion holds even for the most optimistic values of the reconnection probability and loop sizes.Comment: 26 pages, 6 figures; v2: references added and typos correcte

    Genetic Variants of the Renin-Angiotensin-Aldosterone System and Reverse Remodeling After Cardiac Resynchronization Therapy

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    Background: Reverse remodeling (RR) after cardiac resynchronization therapy (CRT) is associated with favorable clinical outcomes in heart failure (HF). The renin-angiotensin-aldosterone system (RAAS) is involved in the remodeling process. Methods and Results: We assessed the association between RR and 8 common RAAS gene variants, which were determined by TaqMan assays, in 156 outpatients with chronic HF. RR was defined as a O15% decrease in left ventricular end systolic volume (LVESV) at 9 (interquartile range 7e12) months after CRT. We matched 76 patients who did not show RR (RR) to 80 RR? control subjects by age, sex, HF etiology, New York Heart Association (NYHA) functional class and left ventricular ejection fraction (LVEF). The frequency of the minor allele of the NR3C2 gene (rs5522 C/T), encoding the mineralocorticoid receptor, was higher in RR than in RR (24/126 vs 10/150; P value after false discovery rate correction: <.0193). Conversely, LVESV decreased significantly less after CRT in carriers of the NR3C2 minor C allele (P 5 .02). After adjustment for age, sex, NYHA functional class, previous myocardial infarction, atrial fibrillation, and LVEF, RR remained independently associated with NR3C2 C allele carriage (odds ratio 3.093, 95% confidence interval 1.253e7.632). Conclusions: The association of RR after CRT with a common polymorphism in the mineralocorticoid receptor gene involved in aldosterone signaling suggests a possible role for variants in RAAS genes in progressive LV function decline, despite apparently effective CRT

    Continuous optimization of cardiac resynchronization therapy reduces atrial fibrillation in heart failure patients: Results of the Adaptive Cardiac Resynchronization Therapy Trial

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    BackgroundData from randomized trials have suggested a modest or no effect of conventional cardiac resynchronization therapy (convCRT) on the incidence of atrial fibrillation (AF). AdaptivCRT (aCRT, Medtronic, Mounds View, MN) is a recently described algorithm for synchronized left ventricular (LV) pacing and continuous optimization of cardiac resynchronization therapy (CRT).ObjectiveWe compared the long-term effects of aCRT with convCRT pacing on the incidence of AF.MethodsThe Adaptive CRT trial randomized CRT-defibrillator (CRT-D)–indicated patients (2:1) to receive either aCRT or convCRT pacing. The aCRT algorithm evaluates intrinsic conduction every minute, providing LV-only pacing during normal atrioventricular (AV) conduction and AV and ventriculoventricular timing adjustments during prolonged AV conduction. The primary outcome of this subanalysis was an episode of AF >48 consecutive hours as detected by device diagnostics.ResultsOver a follow-up period with a mean and standard deviation of 20.2 ± 5.9 months, 8.7% of patients with aCRT and 16.2% with convCRT experienced the primary outcome (hazard ratio [HR] = 0.54; 95% confidence interval [CI] = 0.31–0.93; P = .03). In patients with prolonged baseline AV, the incidence of the primary outcome was 12.8% in patients randomized to aCRT compared with 27.4% in convCRT patients (HR = 0.45; 95% CI = 0.24–0.85; P = .01). Also, patients with AF episodes adjudicated as clinical adverse events were less common with aCRT (4.3%) than with convCRT (12.7%) (HR = 0.39; 95% CI = 0.19–0.79; P = .01).ConclusionPatients receiving aCRT had a reduced risk of AF compared with those receiving convCRT. Most of the reduction in AF occurred in subgroups with prolonged AV conduction at baseline and with significant left atrial reverse remodeling

    Plesiosaurios de la formación Allen (Campaniano-Mastrichtiano) en el área del salitral de Santa Rosa (provincia de Río Negro, Argentina)

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    Fil: O`Gorman, José Patricio. División Paleontología Vertebrados; Facultad de Ciencias Naturales y Museo; Universidad Nacional de La PlataFil: Salgado, Leonardo. INIBIOMAFil: Brandoni de Gasparini, Zulma Nélida. División Paleontología Vertebrados; Facultad de Ciencias Naturales y Museo; Universidad Nacional de La Plat
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