654 research outputs found
State-run schools reconsidered. A reply to Merry
In this reply, the author considers some major points of Michael Merry’s article, “Citizenship, Structural Inequality, and the Political Elite.” Specifically, she discusses how his distinction between civic education and political education raises an important question about the relationship of state-run schooling to modern statecraft, namely, whether it is possible for state-run schools to do anything but reproduce the extant order. (DIPF/Orig.
Education and politics. A reply to Su and Su
In their article, \u27Why solving intergenerational injustice through education does not work\u27, Hanno Su and Shia Su present at least two claims. The first claim is that the fact of climate change refutes the progressive bias in modern educational thought and shifts the task of education away from preparing children for a better future to preparing them for what will likely be a worse future. The second claim is that the present adult generation must respond to climate change, not by resolving to educate the younger generation into \u27better\u27 habits and values, but by assuming responsibility for our part in the crisis, doing as much as possible, as soon as possible, to mitigate its long-term effects. My commentary responds to these two claims. I judge that, while Su and Su are correct to stress the present generation\u27s imperative to assume responsibility for the climate crisis, their deflationary account of education\u27s political function gives short shrift to how education can supplement and secure revolutionary change. (DIPF/Orig.
Rigidity of Orientationally Ordered Domains of Short Chain Molecules
By molecular dynamics simulation, discovered is a strange rigid-like nature
for a hexagonally packed domain of short chain molecules. In spite of the
non-bonded short-range interaction potential (Lennard-Jones potential) among
chain molecules, the packed domain gives rise to a resultant global moment of
inertia. Accordingly, as two domains encounter obliquely, they rotate so as to
be parallel to each other keeping their overall structures as if they were
rigid bodies.Comment: 7 pages, 5 figures, and 2 table
The design, fabrication, and testing of a wind tunnel for the study of the turbulent transport of aerosols
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1992.Includes bibliographical references (leaf 56).by Malcolm S. Child.B.S
Characterization of ligand binding and processing by bombesin receptors in an insulin-secreting cell line
In Vitro Behavior and UV response of melanocytes derived from carriers of CDKN2A mutations and MC1R variants.
Co-inheritance of germline mutation in cyclin-dependent kinase inhibitor 2A (CDKN2A) and loss-of-function (LOF) melanocortin 1 receptor (MC1R) variants is clinically associated with exaggerated risk for melanoma. To understand the combined impact of these mutations, we established and tested primary human melanocyte cultures from different CDKN2A mutation carriers, expressing either wild-type MC1R or MC1R LOF variant(s). These cultures expressed the CDKN2A product p16 (INK4A) and functional MC1R. Except for 32ins24 mutant melanocytes, the remaining cultures showed no detectable aberrations in proliferation or capacity for replicative senescence. Additionally, the latter cultures responded normally to ultraviolet radiation (UV) by cell cycle arrest, JNK, p38, and p53 activation, hydrogen peroxide generation, and repair of DNA photoproducts. We propose that malignant transformation of melanocytes expressing CDKN2A mutation and MC1R LOF allele(s) requires acquisition of somatic mutations facilitated by MC1R genotype or aberrant microenvironment due to CDKN2A mutation in keratinocytes and fibroblasts. This article is protected by copyright. All rights reserved
Atomistic mechanisms for the ordered growth of Co nano-dots on Au(788): comparison of VT-STM experiments and multi-scaled calculations
Hetero-epitaxial growth on a strain-relief vicinal patterned substrate has
revealed unprecedented 2D long range ordered growth of uniform cobalt
nanostructures. The morphology of a Co sub-monolayer deposit on a Au(111)
reconstructed vicinal surface is analyzed by Variable Temperature Scanning
Tunneling Microscopy (VT-STM) experiments. A rectangular array of nano-dots
(3.8 nm x 7.2 nm) is found for a particularly large deposit temperature range
lying from 60 K to 300 K. Although the nanodot lattice is stable at room
temperature, this paper focus on the early stage of ordered nucleation and
growth at temperatures between 35 K and 480 K. The atomistic mechanisms leading
to the nanodots array are elucidated by comparing statistical analysis of
VT-STM images with multi-scaled numerical calculations combining both Molecular
Dynamics for the quantitative determination of the activation energies for the
atomic motion and the Kinetic Monte Carlo method for the simulations of the
mesoscopic time and scale evolution of the Co submonolayer
Spontaneous alloying in binary metal microclusters - A molecular dynamics study -
Microcanonical molecular dynamics study of the spontaneous alloying(SA),
which is a manifestation of fast atomic diffusion in a nano-sized metal
cluster, is done in terms of a simple two dimensional binary Morse model.
Important features observed by Yasuda and Mori are well reproduced in our
simulation. The temperature dependence and size dependence of the SA phenomena
are extensively explored by examining long time dynamics. The dominant role of
negative heat of solution in completing the SA is also discussed. We point out
that a presence of melting surface induces the diffusion of core atoms even if
they are solid-like. In other words, the {\it surface melting} at substantially
low temperature plays a key role in attaining the SA.Comment: 15 pages, 12 fgures, Submitted to Phys.Rev.
On the construction of high-order force gradient algorithms for integration of motion in classical and quantum systems
A consequent approach is proposed to construct symplectic force-gradient
algorithms of arbitrarily high orders in the time step for precise integration
of motion in classical and quantum mechanics simulations. Within this approach
the basic algorithms are first derived up to the eighth order by direct
decompositions of exponential propagators and further collected using an
advanced composition scheme to obtain the algorithms of higher orders. Contrary
to the scheme by Chin and Kidwell [Phys. Rev. E 62, 8746 (2000)], where
high-order algorithms are introduced by standard iterations of a force-gradient
integrator of order four, the present method allows to reduce the total number
of expensive force and its gradient evaluations to a minimum. At the same time,
the precision of the integration increases significantly, especially with
increasing the order of the generated schemes. The algorithms are tested in
molecular dynamics and celestial mechanics simulations. It is shown, in
particular, that the efficiency of the new fourth-order-based algorithms is
better approximately in factors 5 to 1000 for orders 4 to 12, respectively. The
results corresponding to sixth- and eighth-order-based composition schemes are
also presented up to the sixteenth order. For orders 14 and 16, such highly
precise schemes, at considerably smaller computational costs, allow to reduce
unphysical deviations in the total energy up in 100 000 times with respect to
those of the standard fourth-order-based iteration approach.Comment: 23 pages, 2 figures; submitted to Phys. Rev.
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