468 research outputs found

    In War and Peas, Comrades at Farms: Political Intentionality and Construction of Space in a Montreal Farm Collective

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    The central fieldwork site for this research was a farm collective called La Grange, located outside of Montreal in the municipality of Laval, Quebec. This research aims to explore the dynamics of collective organization and the factors involved in the construction of shared political and physical space as they apply to this particular farm project and the changes it has undergone over the course of the three farming seasons during which participant observation was conducted. The theoretical framework for this research follows a trajectory that is in the tradition of the anthropology of social movements, with the concept of prefigurative politics providing a theoretical backdrop for discussions of the practices and political orientations relevant to La Grange and its participants. Prefiguration, and in particular its capacity to translate political theory and ideology into action, provides rich soil for discussions of political intentionality, collective organizing and power dynamics, DIY (Do It Yourself) ethos, anarchist theory, organic farming practices and food justice issues

    A Test Statistic for Weighted Runs

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    A new test statistic based on success runs of weighted deviations is introduced. Its use for observations sampled from independent normal distributions is worked out in detail. It supplements the classic χ2\chi^{2} test which ignores the ordering of observations and provides additional sensitivity to local deviations from expectations. The exact distribution of the statistic in the non-parametric case is derived and an algorithm to compute pp-values is presented. The computational complexity of the algorithm is derived employing a novel identity for integer partitions.Comment: 20 pages, 4 figures. Match published paper as close as possibl

    Revisiting rho 1 Cancri e: A New Mass Determination Of The Transiting super-Earth

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    We present a mass determination for the transiting super-Earth rho 1 Cancri e based on nearly 700 precise radial velocity (RV) measurements. This extensive RV data set consists of data collected by the McDonald Observatory planet search and published data from Lick and Keck observatories (Fischer et al. 2008). We obtained 212 RV measurements with the Tull Coude Spectrograph at the Harlan J. Smith 2.7 m Telescope and combined them with a new Doppler reduction of the 131 spectra that we have taken in 2003-2004 with the High-Resolution-Spectrograph (HRS) at the Hobby-Eberly Telescope (HET) for the original discovery of rho 1 Cancri e. Using this large data set we obtain a 5-planet Keplerian orbital solution for the system and measure an RV semi-amplitude of K = 6.29 +/- 0.21 m/s for rho 1 Cnc e and determine a mass of 8.37 +/- 0.38 M_Earth. The uncertainty in mass is thus less than 5%. This planet was previously found to transit its parent star (Winn et al. 2011, Demory et al. 2011), which allowed them to estimate its radius. Combined with the latest radius estimate from Gillon et al. (2012), we obtain a mean density of rho = 4.50 +/- 0.20 g/cm^3. The location of rho 1 Cnc e in the mass-radius diagram suggests that the planet contains a significant amount of volitales, possibly a water-rich envelope surrounding a rocky core.Comment: 16 pages, 5 figures, accepted for publication in the Astrophysical Journal (the 300+ RV measurements will be published as online tables or can be obtained from the author

    Reef Fish Survey Techniques:Assessing the Potential for Standardizing Methodologies

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    Dramatic changes in populations of fishes living on coral reefs have been documented globally and, in response, the research community has initiated efforts to assess and monitor reef fish assemblages. A variety of visual census techniques are employed, however results are often incomparable due to differential methodological performance. Although comparability of data may promote improved assessment of fish populations, and thus management of often critically important nearshore fisheries, to date no standardized and agreed-upon survey method has emerged. This study describes the use of methods across the research community and identifies potential drivers of method selection. An online survey was distributed to researchers from academic, governmental, and non-governmental organizations internationally. Although many methods were identified, 89% of survey-based projects employed one of three methods-belt transect, stationary point count, and some variation of the timed swim method. The selection of survey method was independent of the research design (i.e., assessment goal) and region of study, but was related to the researcher's home institution. While some researchers expressed willingness to modify their current survey protocols to more standardized protocols (76%), their willingness decreased when methodologies were tied to long-term datasets spanning five or more years. Willingness to modify current methodologies was also less common among academic researchers than resource managers. By understanding both the current application of methods and the reported motivations for method selection, we hope to focus discussions towards increasing the comparability of quantitative reef fish survey data

    Mechanisms Underlying Overactive Bladder and Interstitial Cystitis/Painful Bladder Syndrome

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    The bladder is innervated by extrinsic afferents that project into the dorsal horn of the spinal cord, providing sensory input to the micturition centers within the central nervous system. Under normal conditions, the continuous activation of these neurons during bladder distension goes mostly unnoticed. However, for patients with chronic urological disorders such as overactive bladder syndrome (OAB) and interstitial cystitis/painful bladder syndrome (IC/PBS), exaggerated bladder sensation and altered bladder function are common debilitating symptoms. Whilst considered to be separate pathological entities, there is now significant clinical and pre-clinical evidence that both OAB and IC/PBS are related to structural, synaptic, or intrinsic changes in the complex signaling pathways that mediate bladder sensation. This review discusses how urothelial dysfunction, bladder permeability, inflammation, and cross-organ sensitisation between visceral organs can regulate this neuroplasticity. Furthermore, we discuss how the emotional affective component of pain processing, involving dysregulation of the HPA axis and maladaptation to stress, anxiety and depression, can exacerbate aberrant bladder sensation and urological dysfunction. This review reveals the complex nature of urological disorders, highlighting numerous interconnected mechanisms in their pathogenesis. To find appropriate therapeutic treatments for these disorders, it is first essential to understand the mechanisms responsible, incorporating research from every level of the sensory pathway, from bladder to brain

    Nonequilibrium Neutrino Oscillations in the Early Universe with an Inverted Neutrino-Mass Hierarchy

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    The annihilation of electron-positron pairs around one second after the big bang distorts the Fermi-Dirac spectrum of neutrino energies. We determine the distortions assuming neutrino mixing with an inverted neutrino-mass hierarchy. Nonequilibrium thermodynamics, the Boltzmann equation, and numerical integration are used to achieve the results. The various types of neutrino behavior are established as a function of masses and mixing angles.Comment: 9 pages in Latex with 6 figures (10 postscript files

    Amplitude Changes during Ventricular Fibrillation: A Mechanistic Insight

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    Introduction: Clinically in ventricular fibrillation (VF), ECG amplitude, and frequency decrease as ischemia progresses and predict defibrillation success. In vitro ECG amplitude declines without ischemia, independent of VF frequencies. This study examines the contribution of cellular electrical activity and global organization to ECG amplitude changes during VF. Methods and Results: Rabbit hearts were Langendorff-perfused (40 mL/min, Tyrode’s solution) and loaded with RH237. During VF, ECG, and epicardial optical action potentials were recorded (photodiode array; 256 sites, 15 mm × 15 mm). After 60 s of VF, perfusion was either maintained, global ischemia produced by low-flow (6 mL/min), or solution [K+]o raised to 8 mM. Peak-to-peak amplitude was determined for all signals. During VF, in control, ECG amplitude decreased to a steady-state (∼57% baseline), whereas in low-flow steady-state was not reached with the amplitude continuing to fall to 33% of baseline by 600 s. Optically, LV amplitude declined more than RV, reaching significance in control (LV vs. RV; 33 ± 5 vs. 63 ± 8%, p < 0.01). During VF in 8 mM [K+]o, amplitude changes were more complex; ECG amplitude increased with time (105 ± 13%), whilst LV amplitude decreased (60 ± 15%, p < 0.001). Microelectrode studies showed amplitude reduction in control and 8 mM [K+]o (to ∼79 and ∼93% baseline, respectively). Evaluation of electrical coordination by cross-correlation of optical signals showed as VF progressed coordination reduced in control (baseline 0.36 ± 0.02 to 0.28 ± 0.003, p < 0.01), maintained in low-flow (0.41 ± 0.03 to 0.37 ± 0.005, p = NS) and increased in 8 mM [K+]o (0.36 ± 0.02 to 0.53 ± 0.08, p < 0.05). Conclusion: ECG amplitude decline in VF is due to a combination of decreased systolic activation at the cellular level and increased desynchronization of inter-cellular electrical activity

    Mechanisms Underlying Overactive Bladder and Interstitial Cystitis/Painful Bladder Syndrome

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    Copyright © 2018 Grundy, Caldwell and Brierley. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.The bladder is innervated by extrinsic afferents that project into the dorsal horn of the spinal cord, providing sensory input to the micturition centers within the central nervous system. Under normal conditions, the continuous activation of these neurons during bladder distension goes mostly unnoticed. However, for patients with chronic urological disorders such as overactive bladder syndrome (OAB) and interstitial cystitis/painful bladder syndrome (IC/PBS), exaggerated bladder sensation and altered bladder function are common debilitating symptoms. Whilst considered to be separate pathological entities, there is now significant clinical and pre-clinical evidence that both OAB and IC/PBS are related to structural, synaptic, or intrinsic changes in the complex signaling pathways that mediate bladder sensation. This review discusses how urothelial dysfunction, bladder permeability, inflammation, and cross-organ sensitisation between visceral organs can regulate this neuroplasticity. Furthermore, we discuss how the emotional affective component of pain processing, involving dysregulation of the HPA axis and maladaptation to stress, anxiety and depression, can exacerbate aberrant bladder sensation and urological dysfunction. This review reveals the complex nature of urological disorders, highlighting numerous interconnected mechanisms in their pathogenesis. To find appropriate therapeutic treatments for these disorders, it is first essential to understand the mechanisms responsible, incorporating research from every level of the sensory pathway, from bladder to brain

    Deletion rescue resulting in segmental homozygosity: A mechanism underlying discordant NIPT results

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    With the increasing capabilities of non-invasive prenatal testing (NIPT), detection of sub-chromosomal deletions and duplications are possible. This case series of deletion rescues resulting in segmental homozygosity helps provide a biological explanation for NIPT discrepancies and adds to the dearth of existing literature surrounding segmental UPD cases and their underlying mechanisms. In the three cases presented here, NIPT reported a sub-chromosomal deletion (in isolation or as part of a complex finding). Diagnostic testing, however, revealed segmental homozygosity or UPD for the region reported deleted on NIPT. Postnatal placental testing was pursued in two cases and confirmed the NIPT findings. This discordance between the screening and diagnostic testing is suggestive of a corrective post-zygotic event, such as telomere capture and/or deletion rescue, ultimately resulting in segmental homozygosity and fetoplacental mosaicism. Imprinted chromosomes and autosomal recessive disease genes make homozygosity an important clinical consideration. Amniocentesis with SNP microarray is particularly useful in determining both copy number and UPD issues alike

    Recognition-mediated hydrogel swelling controlled by interaction with a negative thermoresponsive LCST polymer

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    Most polymeric thermoresponsive hydrogels contract upon heating beyond the lower critical solution temperature (LCST) of the polymers used. Herein, we report a supramolecular hydrogel system that shows the opposite temperature dependence. When the non-thermosesponsive hydrogel NaphtGel, containing dialkoxynaphthalene guest molecules, becomes complexed with the tetra cationic macrocyclic host CBPQT4+, swelling occurred as a result of host–guest complex formation leading to charge repulsion between the host units, as well as an osmotic contribution of chloride counter-ions embedded in the network. The immersion of NaphtGel in a solution of poly(N-isopropylacrylamide) with tetrathiafulvalene (TTF) end groups complexed with CBPQT4+ induced positive thermoresponsive behaviour. The LCST-induced dethreading of the polymer-based pseudorotaxane upon heating led to transfer of the CBPQT4+ host and a concomitant swelling of NaphtGel. Subsequent cooling led to reformation of the TTF-based host–guest complexes in solution and contraction of the hydrogel
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