381 research outputs found

    An assessment of myotube morphology, matrix deformation and myogenic mRNA expression in custom-built and commercially available engineered muscle chamber configurations

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    There are several three-dimensional (3D) skeletal muscle (SkM) tissue engineered models reported in the literature. 3D SkM tissue engineering (TE) aims to recapitulate the structure and function of native (in vivo) tissue, within an in vitro environment. This requires the differentiation of myoblasts into aligned multinucleated myotubes surrounded by a biologically representative extracellular matrix (ECM). In the present work, a new commercially available 3D SkM TE culture chamber manufactured from polyether ether ketone (PEEK) that facilitates suitable development of these myotubes is presented. To assess the outcomes of the myotubes within these constructs, morphological, gene expression, and ECM remodeling parameters were compared against a previously published custom-built model. No significant differences were observed in the morphological and gene expression measures between the newly introduced and the established construct configuration, suggesting biological reproducibility irrespective of manufacturing process. However, TE SkM fabricated using the commercially available PEEK chambers displayed reduced variability in both construct attachment and matrix deformation, likely due to increased reproducibility within the manufacturing process. The mechanical differences between systems may also have contributed to such differences, however, investigation of these variables was beyond the scope of the investigation. Though more expensive than the custombuilt models, these PEEK chambers are also suitable for multiple use after autoclaving. As such this would support its use over the previously published handmade culture chamber system, particularly when seeking to develop higher-throughput systems or when experimental cost is not a factor

    Search for the electric dipole moment of the electron with thorium monoxide

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    The electric dipole moment of the electron (eEDM) is a signature of CP-violating physics beyond the Standard Model. We describe an ongoing experiment to measure or set improved limits to the eEDM, using a cold beam of thorium monoxide (ThO) molecules. The metastable H3Δ1H {}^3\Delta_1 state in ThO has important advantages for such an experiment. We argue that the statistical uncertainty of an eEDM measurement could be improved by as much as 3 orders of magnitude compared to the current experimental limit, in a first-generation apparatus using a cold ThO beam. We describe our measurements of the HH state lifetime and the production of ThO molecules in a beam, which provide crucial data for the eEDM sensitivity estimate. ThO also has ideal properties for the rejection of a number of known systematic errors; these properties and their implications are described.Comment: v2: Equation (11) correcte

    Unnormal Sisterhood: Girls Of Color Writing, Reading, Resisting, And Being Together

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    This practitioner research (Cochran-Smith & Lytle, 2009) study explores how a multiracial inquiry group of girls of color mobilized their literacies in service of building solidarity with one another across nondominant differences (Lorde, 2007). The stories and theories of the eight girls in the group, which they named the Unnormal Sisterhood, are centralized in this dissertation in service of adding nuance to conversations about the needs, desires, and brilliance of girls of color. Informed by feminist of color epistemologies (e.g. Anzaldúa, 1983; Collins, 2000; Lorde, 2007), postpositive realist perspectives (Mohanty, 2000; Moya, 2000), sociocultural perspectives of literacy (e.g. Street, 1984), and culturally sustaining/responsive literacy pedagogies (e.g. Ladson Billings, 1995; Paris & Alim, 2017), this study inquires into how the writing practices of girls of color and the pedagogies that center them might provide a platform for the development of what I’ve theorized as “unnormal sisterhood,” a new form of sociality produced as girls of color work towards self and group definitions that honor their simultaneous differences and connectedness. Using ethnographic methods, I gathered data including fieldnotes, interviews, focus groups, and artifacts, and utilized in Vivo and thematic coding and analytic memos to unearth findings. The first finding from this study is that the centralization of girls’ narratives, theories, and understandings in literacy curriculum can help girls of color establish important notions of resistant self-love. Their narratives resist dominant and deficitizing discourses and, instead, illustrate their complexity, artistry, and brilliance. The second finding is that as girls of color engage literate activities that allow them to engage in one an others’ stories and theories, they can progress towards conceptions and enactments of solidarity that honor difference, thereby allowing them to better understand not only how to fight for their own, but also their sisters’ rights and humanity. The third finding is that as girls of color engage in literate activities that center their stories, theories, and ways of knowing, they are able to name and build incisive critiques of systemic oppression

    Measurement of the electron electric dipole moment using YbF molecules

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    The most sensitive measurements of the electron electric dipole moment d_e have previously been made using heavy atoms. Heavy polar molecules offer a greater sensitivity to d_e because the interaction energy to be measured is typically 10^3 times larger than in a heavy atom. We report the first measurement of this kind, for which we have used the molecule YbF. Together, the large interaction energy and the strong tensor polarizability of the molecule make our experiment essentially free of the systematic errors that currently limit d_e measurements in atoms. Our first result d_e = (- 0.2 \pm 3.2) x 10^-26 e.cm is less sensitive than the best atom measurement, but is limited only by counting statistics and demonstrates the power of the method.Comment: 4 pages, 4 figures. v2. Minor corrections and clarifications made in response to referee comment

    Limits on the monopole magnetic field from measurements of the electric dipole moments of atoms, molecules and the neutron

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    A radial magnetic field can induce a time invariance violating electric dipole moment (EDM) in quantum systems. The EDMs of the Tl, Cs, Xe and Hg atoms and the neutron that are produced by such a field are estimated. The contributions of such a field to the constants, χ\chi of the T,P-odd interactions χeNs/s\chi_e {\bf N} \cdot {\bf s}/s and χNNI/I\chi_N {\bf N} \cdot {\bf I}/I are also estimated for the TlF, HgF and YbF molecules (where s{\bf s} (I{\bf I}) is the electron (nuclear) spin and N{\bf N} is the molecular axis). The best limit on the contact monopole field can be obtained from the measured value of the Tl EDM. The possibility of such a field being produced from polarization of the vacuum of electrically charged magnetic monopoles (dyons) by a Coulomb field is discussed, as well as the limit on these dyons. An alternative mechanism involves chromomagnetic and chromoelectric fields in QCD.Comment: Uses RevTex, 16 pages, 4 postscript figures. An explanation of why there is no orbital contribution to the EDM has been added, and the presentation has been improved in genera

    Annual Survey of Virginia Law: Domestic Relations

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    The General Assembly did not take any action regarding the Family Court issue in 1997. In 1996, funding for the family court was delayed until June 1, 1998, subject to state funds being sufficient to provide adequate resources ... for the court to carry out the purposes of [Virginia Code section 20-96] and to fulfill its mission to serve children and families of the Commonwealth

    Transverse Fresnel-Fizeau drag effects in strongly dispersive media

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    A light beam normally incident upon an uniformly moving dielectric medium is in general subject to bendings due to a transverse Fresnel-Fizeau light drag effect. In conventional dielectrics, the magnitude of this bending effect is very small and hard to detect. Yet, it can be dramatically enhanced in strongly dispersive media where slow group velocities in the m/s range have been recently observed taking advantage of the electromagnetically induced transparency (EIT) effect. In addition to the usual downstream drag that takes place for positive group velocities, we predict a significant anomalous upstream drag to occur for small and negative group velocities. Furthermore, for sufficiently fast speeds of the medium, higher order dispersion terms are found to play an important role and to be responsible for peculiar effects such as light propagation along curved paths and the restoration of the spatial coherence of an incident noisy beam. The physics underlying this new class of slow-light effects is thoroughly discussed

    The mechanobiology of tendon fibroblasts under static and uniaxial cyclic load in a 3D tissue engineered model mimicking native ECM

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    Tendon mechanobiology plays a vital role in tendon repair and regeneration; however, this mechanism is currently poorly understood. We tested the role of different mechanical loads on extracellular matrix (ECM) remodelling gene expression and the morphology of tendon fibroblasts in collagen hydrogels, designed to mimic native tissue. Hydrogels were subjected to precise static or uniaxial loading patterns of known magnitudes and sampled to analyse gene expression of known mechano‐responsive ECM‐associated genes (Collagen I, Collagen III, Tenomodulin, and TGF‐β). Tendon fibroblast cytomechanics was studied under load by using a tension culture force monitor, with immunofluorescence and immunohistological staining used to examine cell morphology. Tendon fibroblasts subjected to cyclic load showed that endogenous matrix tension was maintained, with significant concomitant upregulation of ECM remodelling genes, Collagen I, Collagen III, Tenomodulin, and TGF‐β when compared with static load and control samples. These data indicate that tendon fibroblasts acutely adapt to the mechanical forces placed upon them, transmitting forces across the ECM without losing mechanical dynamism. This model demonstrates cell‐material (ECM) interaction and remodelling in preclinical a platform, which can be used as a screening tool to understand tendon regeneration

    A systematic review of the effectiveness and cost-effectiveness of peer education and peer support in prisons.

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    BACKGROUND: Prisoners experience significantly worse health than the general population. This review examines the effectiveness and cost-effectiveness of peer interventions in prison settings. METHODS: A mixed methods systematic review of effectiveness and cost-effectiveness studies, including qualitative and quantitative synthesis was conducted. In addition to grey literature identified and searches of websites, nineteen electronic databases were searched from 1985 to 2012. Study selection criteria were: Population: Prisoners resident in adult prisons and children resident in Young Offender Institutions (YOIs). INTERVENTION: Peer-based interventions Comparators: Review questions 3 and 4 compared peer and professionally led approaches. OUTCOMES: Prisoner health or determinants of health; organisational/ process outcomes; views of prison populations. STUDY DESIGNS: Quantitative, qualitative and mixed method evaluations. RESULTS: Fifty-seven studies were included in the effectiveness review and one study in the cost-effectiveness review; most were of poor methodological quality. Evidence suggested that peer education interventions are effective at reducing risky behaviours, and that peer support services are acceptable within the prison environment and have a positive effect on recipients, practically or emotionally. Consistent evidence from many, predominantly qualitative, studies, suggested that being a peer deliverer was associated with positive effects. There was little evidence on cost-effectiveness of peer-based interventions. CONCLUSIONS: There is consistent evidence from a large number of studies that being a peer worker is associated with positive health; peer support services are also an acceptable source of help within the prison environment and can have a positive effect on recipients. Research into cost-effectiveness is sparse. SYSTEMATIC REVIEW REGISTRATION: PROSPERO ref: CRD42012002349
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