5,501 research outputs found
Towards a Butlerian methodology: undoing organizational performativity through anti-narrative research
This article explores the methodological possibilities that Butlerâs theory of performativity opens up, attempting to âtranslateâ 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 âfixingâ subjects within the research process? The article outlines and evaluates a method described as âanti-narrativeâ 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 Butlerâs 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
Economic Analysis of the Effects of Winter Cover Crops on No-Tillage Corn Yield Response to Fertilizer Nitrogen
Crop Production/Industries,
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Dosimetric comparison study between intensity modulated radiation therapy and three-dimensional conformal proton therapy for pelvic bone marrow sparing in the treatment of cervical cancer.
The objective was to compare intensity-modulated radiation therapy (IMRT) with 3D conformal proton therapy (3DCPT) in the treatment of cervical cancer. In particular, each technique's ability to spare pelvic bone marrow (PBM) was of primary interest in this study. A total of six cervical cancer patients (3 postoperative and 3 intact) were planned and analyzed. All plans had uniform 1.0 cm CTV-PTV margin and satisfied the 95% PTV with 100% isodose (prescription dose = 45 Gy) coverage. Dose-volume histograms (DVH) were analyzed for comparison. The overall PTV and PBM volumes were 1035.9 ± 192.2 cc and 1151.4 ± 198.3 cc, respectively. In terms of PTV dose conformity index (DCI) and dose homogeneity index (DHI), 3DCPT was slightly superior to IMRT with 1.00 ± 0.001, 1.01 ± 0.02, and 1.10 ± 0.02, 1.13 ± 0.01, respectively. In addition, 3DCPT demonstrated superiority in reducing lower doses (i.e., V30 or less) to PBM, small bowel and bladder. Particularly in PBM, average V10 and V20 reductions of 10.8% and 7.4% (p = 0.001 and 0.04), respectively, were observed. However, in the higher dose range, IMRT provided better sparing (> V30). For example, in small bowel and PBM, average reductions in V45 of 4.9% and 10.0% (p = 0.048 and 0.008), respectively, were observed. Due to its physical characteristics such as low entrance dose, spread-out Bragg peak and finite particle range of protons, 3DCPT illustrated superior target coverage uniformity and sparing of the lower doses in PBM and other organs. Further studies are, however, needed to fully exploit the benefits of protons for general use in cervical cancer
Avian blood parasites in an endangered columbid: Leucocytozoon marchouxi in the Mauritian Pink Pigeon Columba mayeri
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
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 â ST (n=22) vs NST (n=22) â 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
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
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 MMP9â/â 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 MMP9â/â 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
Laplace NMR (LNMR) offers deep insights on diffusional and rotational motion of molecules. The so-called âultrafastâ 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 diffusionâT2 relaxation correlation (DâT2) 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 10â8 to 10â12 m2 sâ1) 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 DâT2 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
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
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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