4,977 research outputs found
Edward Thompson's Ethics and Activism 1956–1963: Reflections on the Political Formation of The Making of the English Working Class
As well as a work of history, E. P. Thompson's The Making of the English Class (London: Gollancz, 1963) was written as a strategic intervention in wider political debates of the late 1950s about working class consciousness, identity, agency and organisation, and as a sustained expression and application of ‘socialist humanism’ to historical subjects. This essay situates the book within these debates, moving between The Making and Thompson's writings within the New Left, to show how the characteristic themes of his work—moral choice and agency, the complexities of working-class consciousness and culture, the role of intellectuals and of an ‘organised minority’—were developed through both. This provides us with a richer context for understanding both the moral sensibility that animates the book and key elements of its historiographical standpoint
General Covariance in Quantum Gravity at a Lifshitz Point
In the minimal formulation of gravity with Lifshitz-type anisotropic scaling,
the gauge symmetries of the system are foliation-preserving diffeomorphisms of
spacetime. Consequently, compared to general relativity, the spectrum contains
an extra scalar graviton polarization. Here we investigate the possibility of
extending the gauge group by a local U(1) symmetry to "nonrelativistic general
covariance." This extended gauge symmetry eliminates the scalar graviton, and
forces the coupling constant in the kinetic term of the minimal
formulation to take its relativistic value, . The resulting theory
exhibits anisotropic scaling at short distances, and reproduces many features
of general relativity at long distances.Comment: 41 pages; v2: small clarifications, references adde
Wavelets and their application to digital signal processing in ultrsaonic NDE
As the use of digital based ultrasonic testing systems becomes more prevalent, there will be an increased emphasis on the development of digital signal processing techniques. In the past, various Fourier based digital signal processing approaches have been formulated and applied in the ultrasonic nondestructive evaluation (NDE) research community. In many cases, the inherent inability of Fourier methods to handle non-stationary signals has been exposed as the Fourier methods are applied to non-stationary ultrasonic signals. Our intent is to investigate the application of wavelet based signals processing techniques to a variety of problems in ultrasonic NDE. Wavelet methods have a number of potential advantage over Fourier methods including the inherent ability of wavelets to deal with non-stationary signals
Permutation-adapted complete and independent basis for atomic cluster expansion descriptors
In many recent applications, particularly in the field of atom-centered
descriptors for interatomic potentials, tensor products of spherical harmonics
have been used to characterize complex atomic environments. When coupled with a
radial basis, the atomic cluster expansion (ACE) basis is obtained. However,
symmetrization with respect to both rotation and permutation results in an
overcomplete set of ACE descriptors with linear dependencies occurring within
blocks of functions corresponding to particular generalized Wigner symbols. All
practical applications of ACE employ semi-numerical constructions to generate a
complete, fully independent basis. While computationally tractable, the
resultant basis cannot be expressed analytically, is susceptible to numerical
instability, and thus has limited reproducibility. Here we present a procedure
for generating explicit analytic expressions for a complete and independent set
of ACE descriptors. The procedure uses a coupling scheme that is maximally
symmetric w.r.t. permutation of the atoms, exposing the permutational
symmetries of the generalized Wigner symbols, and yields a permutation-adapted
rotationally and permutationally invariant basis (PA-RPI ACE). Theoretical
support for the approach is presented, as well as numerical evidence of
completeness and independence. A summary of explicit enumeration of PA-RPI
functions up to rank 6 and polynomial degree 32 is provided. The PA-RPI blocks
corresponding to particular generalized Wigner symbols may be either larger or
smaller than the corresponding blocks in the simpler rotationally invariant
basis. Finally, we demonstrate that basis functions of high polynomial degree
persist under strong regularization, indicating the importance of not
restricting the maximum degree of basis functions in ACE models a priori
Delayed Photoionization Feedback in a Super Star Cluster in SBS0335-052E
SBS0335-052 is a well studied Blue Compact Dwarf galaxy with one of the
lowest metallicities of any known galaxy. It also contains 6 previously
identified Super Star Clusters. We combine archival HST NICMOS images in the Pa
alpha line and the 1.6 micron continuum of the eastern component, SBS0335-052E,
with other space and ground based data to perform a multi-wavelength analysis
of the super star clusters. We concentrate on the southern most clusters,
designated S1 and S2, which appear to be the youngest clusters and are the
strongest emitters of Pa alpha, radio, and x-ray flux. Our analysis leads to a
possible model for S1 and perhaps S2 as a cluster of very young, massive stars
with strong stellar winds. The wind density can be high enough to absorb the
majority of ionizing photons within less than 1000 AU of the stars, creating
very compact HII regions that emit optically thick radiation at radio
wavelengths. These winds would then effectively quench the photoionizing flux
very close to the stars. This can delay the onset of negative feedback by
photoionization and photodissociation on star formation in the clusters. This
is significant since SBS0335-052E resembles the conditions that were probably
common for high redshift star formation in galaxies near the epoch of
reionization.Comment: Accepted for publication in the Astrophysical Journa
Modelling the relative cost-effectiveness Of The Rts,S vaccine compared to other recommended malaria interventions
Child and Parent Report of Parenting as Predictors of Substance Use and Suspensions from School
This study examined how child and parent reports of parenting were related to early adolescent substance use and school suspensions. Data were from two time points six months apart on 321 families with an eighth grade student attending one of five schools in the Pacific Northwest. Child- and parent-report measures of family management practices were moderately correlated (r = .29). Child report, but not parent report, of more positive family management practices uniquely predicted a lower likelihood of adolescent substance use. Also, discrepancies between child and parent report of parenting predicted substance use, with child positive report of family management losing its protective association with adolescent substance use when parents had negative reports of their parenting. Parent report, but not child report, of better parenting predicted lower likelihood of suspensions, suggesting that the salience of child and parent report may depend on the type of behavioral outcome
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