298 research outputs found
Social Identity in Deaf Culture: A Comparison of Ideologies
The emergence of Deaf culture and recent developments in identity research fueled by cultural diversity has ignited exploration of identity development in deaf people. The issue of how individuals go through the process of developing identities related to being deaf is now receiving much attention. Two major theoretical models in the literature, specifically racial identity development models and bicultural/acculturation models are presented and then discussed in terms of how they might apply to deaf people. Subsequently, we describe two separate measures that have been developed to empirically test the application of these models to deaf populations. While research on both measures indicates good psychometric properties, ongoing reconceptualization of social identity models that may explain how deaf people develop identities related to Deaf and hearing societies continues to be necessary. It is hoped that these measures will lead to better understanding of the relationship between aspects of identity and healthy psychological adjustment in deaf people
Current Exchanges and Unconstrained Higher Spins
The (Fang-)Fronsdal formulation for free fully symmetric (spinor-) tensors
rests on (gamma-)trace constraints on gauge fields and parameters. When these
are relaxed, glimpses of the underlying geometry emerge: the field equations
extend to non-local expressions involving the higher-spin curvatures, and with
only a pair of additional fields an equivalent ``minimal'' local formulation is
also possible. In this paper we complete the discussion of the ``minimal''
formulation for fully symmetric (spinor-) tensors, constructing one-parameter
families of Lagrangians and extending them to (A)dS backgrounds. We then turn
on external currents, that in this setting are subject to conventional
conservation laws and, by a close scrutiny of current exchanges in the various
formulations, we clarify the precise link between the local and non-local
versions of the theory. To this end, we first show the equivalence of the
constrained and unconstrained local formulations, and then identify a unique
set of non-local Lagrangian equations which behave in exactly the same fashion
in current exchanges.Comment: 37 pages, Latex. Typos corrected, note and references added. Final
version to appear in Nucl. Phys.
Microbiome analysis as a platform R&D tool for parasitic nematode disease management
The relationship between bacterial communities and their host is being extensively investigated for the potential to improve the host’s health. Little is known about the interplay between the microbiota of parasites and the health of the infected host. Using nematode co-infection of lambs as a proof-of-concept model, the aim of this study was to characterise the microbiomes of nematodes and that of their host, enabling identification of candidate nematode-specific microbiota member(s) that could be exploited as drug development tools or for targeted therapy. Deep sequencing techniques were used to elucidate the microbiomes of different life stages of two parasitic nematodes of ruminants, Haemonchus contortus and Teladorsagia circumcincta, as well as that of the co-infected ovine hosts, pre- and post infection. Bioinformatic analyses demonstrated significant differences between the composition of the nematode and ovine microbiomes. The two nematode species also differed significantly. The data indicated a shift in the constitution of the larval nematode microbiome after exposure to the ovine microbiome, and in the ovine intestinal microbial community over time as a result of helminth co-infection. Several bacterial species were identified in nematodes that were absent from their surrounding abomasal environment, the most significant of which included Escherichia coli/Shigella. The ability to purposefully infect nematode species with engineered E. coli was demonstrated in vitro, validating the concept of using this bacterium as a nematode-specific drug development tool and/or drug delivery vehicle. To our knowledge, this is the first description of the concept of exploiting a parasite’s microbiome for drug development and treatment purposes
Self-duality of Born-Infeld action and Dirichlet 3-brane of type IIB superstring theory
D-brane actions depend on a world-volume abelian vector field and are
described by Born-Infeld-type actions. We consider the vector field duality
transformations of these actions. Like the usual 2d scalar duality rotations of
isometric string coordinates imply target space T-duality, this vector duality
is intimately connected with SL(2,Z)-symmetry of type IIB superstring theory.
We find that in parallel with generalised 4-dimensional Born-Infeld action, the
action of 3-brane of type IIB theory is SL(2,Z) self-dual. This indicates that
3-brane should play a special role in type IIB theory and also suggests a
possibility of its 12-dimensional reformulation.Comment: 22 pages, harvmac (minor changes
Effective action of beta-deformed N = 4 SYM theory: Farewell to two-loop BPS diagrams
Within the background field approach, all two-loop sunset vacuum diagrams,
which occur in the Coulomb branch of N = 2 superconformal theories(including N
= 4 SYM), obey the BPS condition m_3 = m_1 + m_2, where the masses are
generated by the scalars belonging to a background N = 2 vector multiplet.
These diagrams can be evaluated exactly, and prove to be homogeneous quadratic
functions of the one-loop tadpoles J(m_1^2), J(m_2^2) and J(m_3^2), with the
coefficients being rational functions of the squared masses. We demonstrate
that, if one switches on the beta-deformation of the N = 4 SYM theory, the BPS
condition no longer holds, and then generic two-loop sunset vacuum diagrams
with three non-vanishing masses prove to be characterized by the following
property: 2(m_1^2 m_2^2 +m_1^2 m_3^2 +m_2^2 m_3^2) > m_1^4 +m_2^4 +m_3^4. In
the literature, there exist several techniques to compute such diagrams. For
the beta-deformed N = 4 SYM theory, we carry out explicit two-loop calculations
of the Kahler potential and F^4 term. Our considerations are restricted to the
case of beta real.Comment: 42 pages, latex, 1 eps figure; V2: references adde
Proof of ultra-violet finiteness for a planar non-supersymmetric Yang-Mills theory
This paper focuses on a three-parameter deformation of N=4 Yang-Mills that
breaks all the supersymmetry in the theory. We show that the resulting
non-supersymmetric gauge theory is scale invariant, in the planar
approximation, by proving that its Green functions are ultra-violet finite to
all orders in light-cone perturbation theory.Comment: 13 pages, 1 figure; v2: minor correction
World-Volume Action of the M Theory Five-Brane
This paper presents a 6d world-volume action that describes the dynamics of
the M theory five-brane in a flat 11d space-time background. The world-volume
action has global 11d super-Poincare invariance, as well as 6d general
coordinate invariance and kappa symmetry, which are realized as local
symmetries. The paper mostly considers a formulation in which general
coordinate invariance is not manifest in one direction. However, it also
describes briefly an alternative formulation, due to Pasti, Sorokin, and Tonin,
in which general coordinate invariance is manifest. The latter approach
requires auxiliary fields and new gauge invariances.Comment: 30 pages, latex, no figure
On higher spins and the tensionless limit of String Theory
We discuss string spectra in the low-tension limit using the BRST formalism,
with emphasis on the role of triplets of totally symmetric tensors and
spinor-tensors and their generalizations to cases with mixed symmetry and to
(A)dS backgrounds. We also present simple compensator forms of the field
equations for individual higher-spin gauge fields that display the
{unconstrained} gauge symmetry of a previous non-local construction and reduce
upon partial gauge fixing to the (Fang-)Fronsdal equations. For Bose fields we
also show how a local Lagrangian formulation with {unconstrained} gauge
symmetry is determined by a previous BRST construction.Comment: 44 pages, LATEX. Improper interpretation of gauge-fixing procedure
for (A)dS triplet removed, misprints corrected, references adde
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