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
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
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 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 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
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
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
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, of the T,P-odd
interactions and are also estimated for the TlF, HgF and YbF molecules (where
() is the electron (nuclear) spin and 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
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
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
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.
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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