5,501 research outputs found

    Towards a Butlerian methodology: undoing organizational performativity through anti-narrative research

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    This article explores the methodological possibilities that Butler’s theory of performativity opens up, attempting to ‘translate’ her theoretical ideas into research practice. Specifically, it considers how research on organizational subjectivity premised upon a performative ontology might be undertaken. It asks: What form might a Butler-inspired methodology take? What methodological opportunities might it afford for developing self-reflexive research? What political and ethical problems might it pose for organizational researchers, particularly in relation to the challenges associated with power asymmetries, and the risks attached to ‘fixing’ subjects within the research process? The article outlines and evaluates a method described as ‘anti-narrative’ interviewing, arguing that it constitutes a potentially valuable methodological resource for researchers interested in understanding how and why idealized organizational subjectivities are formed and sustained. It further advances the in-roads that Butler’s writing has made into organization studies, thinking through the methodological and ethical implications of her work for understanding the performative constitution of organizational subjectivities. The aim of the paper is to advocate a research practice premised upon a reflexive undoing of organizational subjectivities and the normative conditions upon which they depend. It concludes by emphasizing the potential benefits and wider implications of a methodologically reflexive undoing of organizational performativity

    Avian blood parasites in an endangered columbid: Leucocytozoon marchouxi in the Mauritian Pink Pigeon Columba mayeri

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    There is increasing evidence that pathogens can play a significant role in species decline. This study of a complete free-living species reveals a cost of blood parasitism to an endangered host, the Pink Pigeon Columba mayeri, endemic to Mauritius. We investigated the prevalence and effect of infection of the blood parasite, Leucocytozoon marchouxi, in the free-living Pink Pigeon population. Overall, L. marchouxi infection prevalence detected was 18·3%. Juveniles were more likely to be infected than older birds and there was geographical variation in infection prevalence. Survival of birds infected with L. marchouxi was lower than that of uninfected birds to 90 days post-sampling. This study suggests that while common haematozoa are well tolerated in healthy adults, these parasites may have greater pathogenic potential in susceptible juveniles. The study is unusual given its completeness of species sampling (96%) within a short time-period, the accurate host age data, and its focus on blood parasites in a threatened bird species. Species for which long-term life-history data are available for every individual serve as valuable models for dissecting the contribution of particular pathogens to species decline

    The Performance Profile of a Division I Football Team

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    Reporting athletic performance characteristics of a Division I collegiate football team may serve to inform coaching personnel and sports performance staff about the most versatile players to utilize for various competitions. Performance data may also help guide developing athletes about benchmarks to achieve for optimal competitiveness. PURPOSE: Our aim was to observe athletic performance characteristics of and differences between designated starters (ST) vs non-starters (NST). METHODS: 44 athletes – ST (n=22) vs NST (n=22) – were selected using a convenience sample and equally distributed between offense and defense positions. Preseason performance data were analyzed related to select power, including counter movement jump (CMJ), vertical jump (VJ), and Nordic hamstring (NH) tests; and select strength assessments, including 1 repetition max (RM) on power clean (PC), front squat (FS), and bench press (BP). All tests were conducted by sport performance staff using free weights and VALD Performance (Queensland, Australia) equipment (i.e., NordBord, ForceDecks) and software. Data were analyzed via a two sampled equal variance, right-tailed t-test with a significance level set at p \u3c 0.05 and reported as mean±SD. RESULTS: The average age, height, and weight for ST vs. NST, respectively, were 21.2±1.4 & 20.4±1.0 y, 1.8±.4 & 1.9±.1 m, and 104.3±32.1 & 100.4±20.0 kg. Power related to CMJ peak, VJ, NH max of right + left leg averaged, and NH impulse between ST vs. NST were, respectively: 62±9.3 vs. 67.5±12.4 W/kg (p=0.053), .7±.1 vs. .7±.1 m (p=0.444), 553.1±61.3 vs. 478.0±142.1 N (p=0.017), and 7982.1±2235.6 vs 6833.8±1952.4 NS (p=0.040). PC, FS, and BP for ST vs NST were, respectively: 133.4±13.8 vs. 122.4±10.9 kg (p=0.004), 164.5±23.5 vs. 146.7±38.2 kg (p=0.049), and 140.8±20.7 vs. 132.9±15.9 kg (p=0.095). CONCLUSION: Specific to the group observed, there appears to be select power and strength performance characteristics that separate ST and NST. ST might be advised to maintain and NST should strive to achieve explosiveness and strength as described herein via augmented bilateral NH force and impulse in addition to developing a high 1 RM PC. Despite the ambiguity of athletic performance tests to identify talent and skill, coaches and players still might be able to utilize these standards for individualized success

    Biopolymer dynamics driven by helical flagella

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    Microbial flagellates typically inhabit complex suspensions of polymeric material which can impact the swimming speed of motile microbes, filter-feeding of sessile cells, and the generation of biofilms. There is currently a need to better understand how the fundamental dynamics of polymers near active cells or flagella impacts these various phenomena, in particular the hydrodynamic and steric influence of a rotating helical filament on suspended polymers. Our Stokesian dynamics simulations show that as a stationary rotating helix pumps fluid along its long axis, polymers migrate radially inwards while being elongated. We observe that the actuation of the helix tends to increase the probability of finding polymeric material within its pervaded volume. This accumulation of polymers within the vicinity of the helix is stronger for longer polymers. We further analyse the stochastic work performed by the helix on the polymers and show that this quantity is positive on average and increases with polymer contour length.Comment: 14 pages, 6 figure

    MMP9 mediates acute hyperglycemia-induced human cardiac stem cell death by upregulating apoptosis and pyroptosis in vitro

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    Providing a conducive microenvironment is critical to increase survival of transplanted stem cells in regenerative therapy. Hyperglycemia promotes stem cell death impairing cardiac regeneration in the diabetic heart. Understanding the molecular mechanisms of high glucose-induced stem cell death is important for improving cardiac regeneration in diabetic patients. Matrix metalloproteinase-9 (MMP9), a collagenase, is upregulated in the diabetic heart, and ablation of MMP9 decreases infarct size in the non-diabetic myocardial infarction heart. In the present study, we aim to investigate whether MMP9 is a mediator of hyperglycemia-induced cell death in human cardiac stem cells (hCSCs) in vitro. We created MMP9−/− hCSCs to test the hypothesis that MMP9 mediates hyperglycemia-induced oxidative stress and cell death via apoptosis and pyroptosis in hCSCs, which is attenuated by the lack of MMP9. We found that hyperglycemia induced oxidative stress and increased cell death by promoting pyroptosis and apoptosis in hCSCs, which was prevented in MMP9−/− hCSCs. These findings revealed a novel intracellular role of MMP9 in mediating stem cell death and provide a platform to assess whether MMP9 inhibition could improve hCSCs survival in stem cell therapy at least in acute hyperglycemic microenvironment

    Probing Molecular Dynamics with Hyperpolarized Ultrafast Laplace NMR Using a Low-field, Single-sided Magnet

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    Laplace NMR (LNMR) offers deep insights on diffusional and rotational motion of molecules. The so-called “ultrafast” approach, based on spatial data encoding, enables one to carry out a multidimensional LNMR experiment in a single scan, providing from 10 to 1000-fold acceleration of the experiment. Here, we demonstrate the feasibility of ultrafast diffusion–T2 relaxation correlation (D–T2) measurements with a mobile, low-field, relatively low-cost, single-sided NMR magnet. We show that the method can probe a broad range of diffusion coefficients (at least from 10−8 to 10−12 m2 s−1) and reveal multiple components of fluids in heterogeneous materials. The single-scan approach is demonstrably compatible with nuclear spin hyperpolarization techniques because the time-consuming hyperpolarization process does not need to be repeated. Using dynamic nuclear polarization (DNP), we improved the NMR sensitivity of water molecules by a factor of 105 relative to non-hyperpolarized NMR in the 0.3 T field of the single-sided magnet. This enabled us to acquire a D–T2 map in a single, 22 ms scan, despite the low field and relatively low mole fraction (0.003) of hyperpolarized water. Consequently, low-field, hyperpolarized ultrafast LNMR offers significant prospects for advanced, mobile, low-cost and high-sensitivity chemical and medical analysis

    Controls on the rheological properties of peridotite at a palaeosubduction interface: A transect across the base of the Oman-UAE ophiolite

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    Studies of experimentally deformed rocks and small-scale natural shear zones have demonstrated that volumetrically minor phases can control strain localisation by limiting grain growth and promoting grain-size sensitive deformation mechanisms. These small-scale studies are often used to infer a critical role for minor phases in the development of plate boundaries. However, the role of minor phases in strain localisation at an actual plate boundary remains to be tested by direct observation. In order to test the hypothesis that minor phases control strain localisation at plate boundaries, we conducted microstructural analyses of peridotite samples collected along a ~1 km transect across the base of the Oman-United Arab Emirates (UAE) ophiolite. The base of the ophiolite is marked by the Semail thrust, which represents the now exhumed contact between subducted oceanic crust and the overlying mantle wedge. As such, the base of the ophiolite provides the opportunity to directly examine a former plate boundary. Our results demonstrate that the mean olivine grain size is inversely proportional to the abundance of minor phases (primarily orthopyroxene, as well as clinopyroxene, hornblende, and spinel), consistent with suppression of grain growth by grain-boundary pinning. Our results also reveal that mean olivine grain size is proportional to CPO strength (both of which generally decrease towards the metamorphic sole), suggesting that the fraction of strain produced by different deformation mechanisms varied spatially. Experimentally-derived flow laws indicate that under the inferred deformation conditions, the viscosity of olivine was grain-size sensitive. As such, grain size, and thereby the abundance of minor phases, influenced viscosity during subduction-related deformation along the base of the mantle wedge. We calculate an order of magnitude decrease in the viscosity of olivine towards the base of the ophiolite, which suggests strain was localized near the subduction interface. Our data indicate that this rheological weakening was primarily the result of more abundant minor phases near the base of the ophiolite. Our interpretations are consistent with those of previous studies on experimentally deformed rocks and smaller-scale natural shear zones that indicate minor phases can exert the primary control on strain localisation. However, our study demonstrates for the first time that minor phases can control strain localisation at the scales relevant to a major plate boundar

    Background and design of a qualitative study on globally responsible decision-making in civil engineering

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    Organizations that regulate civil engineering have been pressing for integration of 'global responsibility' into higher education curricula since around 2006, with a goal of achieving environmental sustainability and social justice. In an effort led by the American Society of Civil Engineers (ASCE, 2007, 2009), a global vision for civil engineering was identified. Within the UK, the Institution of Civil Engineers (ICE) has been leading the way alongside non-governmental organizations (Bourn & Neal, 2008). Via the in-progress study reported here, a UK-based research team is now studying the effects of ACSE and ICE initiatives. The team seeks to benchmark how global responsibility is perceived and enacted in civil engineering in the UK today and how engineering graduates have learned about and experienced globally responsible decision-making. Findings will hold value for the global community, as achieving sustainability is crucial to humanity, and indeed all life on Earth
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