885 research outputs found
Decolonizing the Mind with Ngugi Wa Thiong\u27o and Chinua Achebe: Searching for a Voice in Postcolonial African Literature
Any discussion of postcolonial African literature requires consideration of both the inherent diversity of “African” and the complex history of colonialism throughout Africa. Ngugi wa Thiong’o claims there are “broad affinities” among the diverse peoples of sub-Saharan Africa which allow for a broad discussion of the common experiences of colonialism, but it is necessary to complement these broad affinities with specific cultural references and historic contexts. This paper attempts to delineate some of the common struggles facing postcolonial African peoples by focusing on the specific writings of Kenya’s Ngugi wa Thiong’o and Nigeria’s Chinua Achebe. Though they are from disparate regions within Africa, Ngugi and Achebe share the common experiences of being subjects to British colonial rule and, later, of witnessing the births of their respective nations. From their common experiences, several key issues pertaining to postcolonial literature emerge, namely the political and cultural implications of retaining English as the lingua franca in an independent African nation. The debates concerning the role of English in postcolonial African nations inspires serious consideration of the relationship between a language and its people, the relevance of a language to cultural identity, and, as the Alice Walker discussion willdemonstrate, the ideological conflict between cultural autonomy and cultural chauvinism.
A close analysis of the primary works of Ngugi wa Thiong’o and Chinua Achebe reveals a political imperative from each author. Exploring this relationship between literature and politics, this paper will attempt to present and then address several of the key political issues portrayed by Ngugi and Achebe. To complement these primary works, the paper employs additional secondary sources to help develop a conceptual framework through which Ngugi and Achebe can be read and interpreted.
This paper will not pretend to be exhaustive in exploring the many serious issues facing postcolonial African peoples, and it will not presume to solve the issues it does address. Rather, this study provides a starting point for understanding the dynamics of two of Africa’s leading contemporary writers and thinkers-Ngugi wa Thiong’o and Chinua Achebe-and a forum for addressing the complexity inherent to the postcolonial discussion itsel
Adjoint-based inversion for stress and frictional parameters in earthquake modeling
We present an adjoint-based optimization method to invert for stress and
frictional parameters used in earthquake modeling. The forward problem is
linear elastodynamics with nonlinear rate-and-state frictional faults. The
misfit functional quantifies the difference between simulated and measured
particle displacements or velocities at receiver locations. The misfit may
include windowing or filtering operators. We derive the corresponding adjoint
problem, which is linear elasticity with linearized rate-and-state friction
with time-dependent coefficients derived from the forward solution. The
gradient of the misfit is efficiently computed by convolving forward and
adjoint variables on the fault. The method thus extends the framework of
full-waveform inversion to include frictional faults with rate-and-state
friction. In addition, we present a space-time dual-consistent discretization
of a dynamic rupture problem with a rough fault in antiplane shear, using
high-order accurate summation-by-parts finite differences in combination with
explicit Runge--Kutta time integration. The dual consistency of the
discretization ensures that the discrete adjoint-based gradient is the exact
gradient of the discrete misfit functional as well as a consistent
approximation of the continuous gradient. Our theoretical results are
corroborated by inversions with synthetic data. We anticipate that
adjoint-based inversion of seismic and/or geodetic data will be a powerful tool
for studying earthquake source processes; it can also be used to interpret
laboratory friction experiments.Comment: Updated title, added additional references, provided additional
details in sections 1 and 5, fixed typo
EMG and Motion Analysis of Swiss Ball Abdominal Exercises and Pilates Multi-Chair Exercises
As the second most common reason for visits to primary care doctors, and a symptom that affects 80% of the general United States population, low back pain and its\u27 treatment is a burdening cost on the American economy every year. Various spinal stabilization exercises have emerged as a means to treat low back pain. One of the most recent fonns of these stabilization exercises used in the physical therapy arena is Pilates, a fonn of dynamic spinal stabilization. Although numerous electromyographic (EMG) studies have been completed on abdominal exercises for spinal stabilization, minimal scientific research can be found on the efficacy of Pilates equipment in this realm. The purpose of this study is to analyze and evaluate the EMG activity in the rectus abdominis, external obliques, and internal obliques using four abdominal exercises: the abdominal crunch on a ball, the abdominal crunch with rotation on a ball, the abdominal crunch on the Pilates Multi-Chair, and the abdominal crunch with rotation on the Pilates Multi-Chair.
Fourteen, healthy subjects between the ages of 18 and 45 years of age performed a maximal voluntary contraction (MVC) and one trial of each abdominal exercise. Abdominal EMG activity was recorded through surface electrodes and then normalized to percent MVC (%MVC) by comparing the muscle activity in the trial with the muscle activity during the reference MVC.
Results of this study showed a significant difference in % MVC among exercises in the left external oblique, upper rectus abdominis, and lower rectus abdominis. There was no significant difference in % MVC among exercises in the right external oblique, and the right and left internal obliques. In general, exercises on the ball produced a higher % MVC in the rectus abdominis and the exercises on the Pilates Multi-Chair produced a higher % MVC in the external obliques
Peculiarities in produced particles emission in 208Pb + Ag(Br) interactions at 158 A GeV/c
The angular structures of particles produced in 208Pb induced collisions with
Ag(Br) nuclei in an emulsion detector at 158 A GeV/c have been investigated.
Nonstatistical ring-like substructures in azimuthal plane of the collision have
been found and their parameters have been determined. The indication on the
formation of the ring-like substructures from two symmetrical emission cones -
one in the forward and other in the backward direction in the center-of mass
system have been obtained. The ring-like substructures parameters have been
determined. The experimental results are in an agreement with I.M. Dremin idea,
that mechanism of the ring-like substructures formation in nuclear collisions
is similar to that of Cherenkov electromagnetic radiation.Comment: 10 pages, 7 figures, Report at the HADRON STRUCTURE'04 Conference,
Smolenice, Slovakia, 30.8.-3.9.200
Anagen hair follicles transplanted into mature human scars remodel fibrotic tissue
Despite the substantial impact of skin scarring on patients and the healthcare system, there is a lack of strategies to prevent scar formation, let alone methods to remodel mature scars. Here, we took a unique approach inspired by how healthy hairbearing skin undergoes physiological remodelling during the regular cycling of hair follicles. In this pilot clinical study, we tested if hair follicles transplanted into human scars can facilitate tissue regeneration and actively remodel fibrotic tissue, similar to how they remodel the healthy skin. We collected full-thickness skin biopsies and compared the morphology and transcriptional signature of fibrotic tissue before and after transplantation. We found that hair follicle tranplantation induced an increase in the epidermal thickness, interdigitation of the epidermal-dermal junction, dermal cell density, and blood vessel density. Remodelling of collagen type I fibres reduced the total collagen fraction, the proportion of thick fibres, and their alignment. Consistent with these morphological changes, we found a shift in the cytokine milieu of scars with a long-lasting inhibition of pro-fibrotic factors TGFβ1, IL13, and IL-6. Our results show that anagen hair follicles can attenuate the fibrotic phenotype, providing new insights for developing regenerative approaches to remodel mature scars
A Relational Event Approach to Modeling Behavioral Dynamics
This chapter provides an introduction to the analysis of relational event
data (i.e., actions, interactions, or other events involving multiple actors
that occur over time) within the R/statnet platform. We begin by reviewing the
basics of relational event modeling, with an emphasis on models with piecewise
constant hazards. We then discuss estimation for dyadic and more general
relational event models using the relevent package, with an emphasis on
hands-on applications of the methods and interpretation of results. Statnet is
a collection of packages for the R statistical computing system that supports
the representation, manipulation, visualization, modeling, simulation, and
analysis of relational data. Statnet packages are contributed by a team of
volunteer developers, and are made freely available under the GNU Public
License. These packages are written for the R statistical computing
environment, and can be used with any computing platform that supports R
(including Windows, Linux, and Mac).
Unraveling the Pharmacokinetic Interaction of Ticagrelor and MEDI2452 (Ticagrelor Antidote) by Mathematical Modeling
The investigational ticagrelor-neutralizing antibody fragment, MEDI2452, is developed to rapidly and specifically reverse the antiplatelet effects of ticagrelor. However, the dynamic interaction of ticagrelor, the ticagrelor active metabolite (TAM), and MEDI2452, makes pharmacokinetic (PK) analysis nontrivial and mathematical modeling becomes essential to unravel the complex behavior of this system. We propose a mechanistic PK model, including a special observation model for post-sampling equilibration, which is validated and refined using mouse in vivo data from four studies of combined ticagrelor-MEDI2452 treatment. Model predictions of free ticagrelor and TAM plasma concentrations are subsequently used to drive a pharmacodynamic (PD) model that successfully describes platelet aggregation data. Furthermore, the model indicates that MEDI2452-bound ticagrelor is primarily eliminated together with MEDI2452 in the kidneys, and not recycled to the plasma, thereby providing a possible scenario for the extrapolation to humans. We anticipate the modeling work to improve PK and PD understanding, experimental design, and translational confidence
Parton cascade description of relativistic heavy-ion collisions at CERN SPS energies ?
We examine Pb+Pb collisions at CERN SPS energy 158 A GeV, by employing the
earlier developed and recently refined parton-cascade/cluster-hadronization
model and its Monte Carlo implementation. This space-time model involves the
dynamical interplay of perturbative QCD parton production and evolution, with
non-perturbative parton-cluster formation and hadron production through cluster
decays. Using computer simulations, we are able to follow the entwined
time-evolution of parton and hadron degrees of freedom in both position and
momentum space, from the instant of nuclear overlap to the final yield of
particles. We present and discuss results for the multiplicity distributions,
which agree well with the measured data from the CERN SPS, including those for
K mesons. The transverse momentum distributions of the produced hadrons are
also found to be in good agreement with the preliminary data measured by the
NA49 and the WA98 collaboration for the collision of lead nuclei at the CERN
SPS. The analysis of the time evolution of transverse energy deposited in the
collision zone and the energy density suggests an existence of partonic matter
for a time of more than 5 fm.Comment: 16 pages including 7 postscript figure
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