16,538 research outputs found
Accounting for competitive advantage: The resource-based view of the firm and the labour theory of value
This article uses accounting concepts to assist the field of strategic
management in its search for a theory of value, competitive advantage and
superior profitability. Specifically, it argues that the resource-based view of
the firm requires a labour theory of value creation. Using the circuit of
capital as an organizing framework this article integrates RBV and Marx's value
theory, by introducing the notion of value as socially necessary labour time,
into the analysis of resource-based advantage. This enables us to identify the
impact of particular sources of competitive advantage as they become diffused
through an industry. Some resource-based advantages, when eventually imitated
lead to an overall reduction in industry profitability, and other advantages
lead to increases in industry average profitability
A Reciprocity Result for Projective Indecomposable Modules of Cellular Algebras and BGG Algebras
We show that an adaptation of Landrock's Lemma for symmetric algebras also
holds for cellular algebras and BGG algebras. This is a result relating the
radical layers of any two projective modules. The reason it holds in our
setting is that there is a duality between injective hulls and projective
covers. As a corollary we deduce that BGG reciprocity respects Loewy structure
Consistency of parity-violating pion-nucleon couplings extracted from measurements in 18F and 133Cs
The recent measurement of the nuclear anapole moment of 133Cs has been
interpreted to yield a value of the weak pion-nucleon coupling H_pi^1 which
contradicts the upper limit from the 18F experiments. We argue that because of
the sensitivity of the anapole moment to H_rho^0 in the odd proton nucleus
133Cs, there is a combination of weak meson-nucleon couplings which satisfies
both experiments and which is (barely) in agreement with theory. In addition,
the anapole moment measurement in 205Tl gives a constraint which is
inconsistent with the value from 133Cs, calling into question the theory of
nuclear anapole moments. We argue that measurements of directional asymmetry in
n+p-->d+gamma and in the photo-disintegration of the deuteron by circularly
polarized photons, combined with results from pp scattering, would determine
H_pi^1 and several other weak meson-nucleon couplings in a model-independent
way.Comment: 9 pages, RevTeX, 1 figure, eps, submitted to Phys. Rev.
Alkane hydroxylase genes in psychrophile genomes and the potential for cold active catalysis.
BackgroundPsychrophiles are presumed to play a large role in the catabolism of alkanes and other components of crude oil in natural low temperature environments. In this study we analyzed the functional diversity of genes for alkane hydroxylases, the enzymes responsible for converting alkanes to more labile alcohols, as found in the genomes of nineteen psychrophiles for which alkane degradation has not been reported. To identify possible mechanisms of low temperature optimization we compared putative alkane hydroxylases from these psychrophiles with homologues from nineteen taxonomically related mesophilic strains.ResultsSeven of the analyzed psychrophile genomes contained a total of 27 candidate alkane hydroxylase genes, only two of which are currently annotated as alkane hydroxylase. These candidates were mostly related to the AlkB and cytochrome p450 alkane hydroxylases, but several homologues of the LadA and AlmA enzymes, significant for their ability to degrade long-chain alkanes, were also detected. These putative alkane hydroxylases showed significant differences in primary structure from their mesophile homologues, with preferences for specific amino acids and increased flexibility on loops, bends, and α-helices.ConclusionA focused analysis on psychrophile genomes led to discovery of numerous candidate alkane hydroxylase genes not currently annotated as alkane hydroxylase. Gene products show signs of optimization to low temperature, including regions of increased flexibility and amino acid preferences typical of psychrophilic proteins. These findings are consistent with observations of microbial degradation of crude oil in cold environments and identify proteins that can be targeted in rate studies and in the design of molecular tools for low temperature bioremediation
3D Computational Ghost Imaging
Computational ghost imaging retrieves the spatial information of a scene
using a single pixel detector. By projecting a series of known random patterns
and measuring the back reflected intensity for each one, it is possible to
reconstruct a 2D image of the scene. In this work we overcome previous
limitations of computational ghost imaging and capture the 3D spatial form of
an object by using several single pixel detectors in different locations. From
each detector we derive a 2D image of the object that appears to be illuminated
from a different direction, using only a single digital projector as
illumination. Comparing the shading of the images allows the surface gradient
and hence the 3D form of the object to be reconstructed. We compare our result
to that obtained from a stereo- photogrammetric system utilizing multiple high
resolution cameras. Our low cost approach is compatible with consumer
applications and can readily be extended to non-visible wavebands.Comment: 13pages, 4figure
Gene-knockdown in the honey bee mite Varroa destructor by a non-invasive approach : studies on a glutathione S-transferase
Peer reviewedPublisher PD
Spin-tunnel investigation of a 1/13-scale model of the NASA AD-1 oblique-wing research aircraft
The spin and recovery characteristics of a 1/13-scale model of the NASA AD-1 oblique-wing research aircraft at wing-skew positions of 0, 25, 45, and 60 deg (right wing forward) were investigated. Spins were obtained for all wing-skew positions tested. For the unskewed wing position, two spin modes were possible. One spin mode was very steep and recoveries were obtained within 1 turn or less by rudder reversal. The second spin mode was flat and fast; the angle of attack was about 75 deg and the spin rate was about 145 deg/sec (2.5 seconds per turn). For the skewed wing positions, spins were obtained only in the direction of the forward-skewed wing (right wing forward). No spins were obtained to the left when the wing was skewed with the right wing forward. Recoveries should be attempted by deflecting the rudder to full against the spin, the ailerons to full with the spin, and movement of the wings to 0 deg skew. If the wing is skewed, the recovery may not be effected until the wing skew approaches 0 deg
Critical Points in the Linear Sigma Model with Quarks
We employ a simple effective model to study the chiral dynamics of two
flavors of quarks at finite temperature and density. In particular, we
determine the phase diagram in the plane of temperature and baryon chemical
potential as a function of the pion mass. An interesting phase structure occurs
which results in zero, one or two critical points depending on the value of the
vacuum pion mass.Comment: 16 pages plus 5 figure
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