19,751 research outputs found
“The feeling of fear was not from my student, but from myself”: A pre-service teacher’s shift from traditional to problem-posing second language pedagogy in a Mexican youth prison
This era of globalization, capitalism, and economic progress has given rise to mass incarceration, as a considerable number of youths in developing and developed countries live behind bars in detention facilities without appropriate educational support. Educators in these facilities deposit knowledge, through traditional pedagogical approaches, under systemic oppression and surveillance deemed necessary for safety and security. This study investigated implementations of Freire’s (2000) problem-posing pedagogy using a participatory action research (PAR) approach through the lens of critical theory. Two of the co-authors helped develop a Freirean language teaching program in an urban youth prison in Mexico, centering student teachers’ critical self-awareness by providing them with opportunities to reflect on their identity, life experiences, and reality while teaching in prison. Through critical, autoethnographic self-reflections of a bilingual teacher candidate on her teaching practices, this study provides insights into how the teacher was impacted by the problem-posing pedagogy and how it was reflected in her transformation to a critical, loving teacher and student progress. This research embraces a humanistic approach to teaching incarcerated youth in Mexico through care and courage by supporting them as students, as well as by empowering their voices and thoughts. Building a learning community, where students and teachers create respectful human connections through dialogue and discussions on language, culture, and lived experiences, is portrayed in this research as essential
On the Penrose Inequality for general horizons
For asymptotically flat initial data of Einstein's equations satisfying an
energy condition, we show that the Penrose inequality holds between the ADM
mass and the area of an outermost apparent horizon, if the data are restricted
suitably. We prove this by generalizing Geroch's proof of monotonicity of the
Hawking mass under a smooth inverse mean curvature flow, for data with
non-negative Ricci scalar. Unlike Geroch we need not confine ourselves to
minimal surfaces as horizons. Modulo smoothness issues we also show that our
restrictions on the data can locally be fulfilled by a suitable choice of the
initial surface in a given spacetime.Comment: 4 pages, revtex, no figures. Some comments added. No essential
changes. To be published in Phys. Rev. Let
Observation of dispersive wave emission by temporal cavity solitons
We examine a coherently-driven, dispersion-managed, passive Kerr fiber ring
resonator and report the first direct experimental observation of dispersive
wave emission by temporal cavity solitons. Our observations are in excellent
agreement with analytical predictions and they are fully corroborated by
numerical simulations. These results lead to a better understanding of the
behavior of temporal cavity solitons under conditions where higher-order
dispersion plays a significant role. Significantly, since temporal cavity
solitons manifest themselves in monolithic microresonators, our results are
likely to explain the origins of spectral features observed in broadband Kerr
frequency combs.Comment: 4 pages, 3 figure
Isometric Representations of Totally Ordered Semigroups
Let S be a subsemigroup of an abelian torsion-free group G. If S is a
positive cone of G, then all C*-algebras generated by faithful isometrical
non-unitary representations of S are canonically isomorphic. Proved by Murphy,
this statement generalized the well-known theorems of Coburn and Douglas. In
this note we prove the reverse. If all C*-algebras generated by faithful
isometrical non-unitary representations of S are canonically isomorphic, then S
is a positive cone of G. Also we consider G = Z\times Z and prove that if S
induces total order on G, then there exist at least two unitarily not
equivalent irreducible isometrical representation of S. And if the order is
lexicographical-product order, then all such representations are unitarily
equivalent.Comment: February 21, 2012. Kazan, Russi
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