45,901 research outputs found
AN EMPIRICAL ANALYSIS OF PUBLIC AND PRIVATE SPILLOVERS WITHIN THE CANOLA BIOTECH INDUSTRY
The study uses firm-specific data in the biotech canola industry to empirically examine research spillovers among public and private firms at the level of research output, research sales revenue, and research social revenue. The non-pecuniary spillovers that are examined include basic research, human capital/ knowledge (as measured through other-firm expenditures) and genetics (as measured through yields of other-firms). The results provide strong empirical evidence of several research spillovers in the biotech crop research industry such as: basic and applied public research creates a positive spillover for private firms at all levels; applied expenditure within-group reduces other-firm revenue while between-group expenditure increases revenue; genetic spillovers within-group have a positive impact on yield but tend to have a negative impact on firm revenue.Agribusiness,
Pecuniary, Non-Pecuniary, and Downstream Research Spillovers: The Case of Canola
This paper develops an empirical framework for estimating a number of inter-firm and downstream research spillovers in the canola crop research industry. The spillovers include basic research, human capital/ knowledge (as measured through other-firm expenditures), and genetics (as measured through yields of other-firms). The model used to examine spillover effects on research productivity provides evidence that there are many positive inter-firm non-pecuniary research spillovers, which is consistent with a research clustering effect. The second model, which examines spillovers at the level of firm revenue , shows that, while private firms tend to crowd one another, public firm expenditure on basic and applied research creates a crowding-in effect for private firms. This model also shows that enhanced intellectual property rights have increased the revenues of private firms. The third model, which examines social value of each firm's output, provides evidence that downstream research spillovers remain important in this modern crop research industry.basic research, applied research, public research expenditures, private research expenditures, biotechnology, Research and Development/Tech Change/Emerging Technologies, O3,
AdS Strings with Torsion: Non-complex Heterotic Compactifications
Combining the effects of fluxes and gaugino condensation in heterotic
supergravity, we use a ten-dimensional approach to find a new class of
four-dimensional supersymmetric AdS compactifications on almost-Hermitian
manifolds of SU(3) structure. Computation of the torsion allows a
classification of the internal geometry, which for a particular combination of
fluxes and condensate, is nearly Kahler. We argue that all moduli are fixed,
and we show that the Kahler potential and superpotential proposed in the
literature yield the correct AdS radius. In the nearly Kahler case, we are able
to solve the H Bianchi using a nonstandard embedding. Finally, we point out
subtleties in deriving the effective superpotential and understanding the
heterotic supergravity in the presence of a gaugino condensate.Comment: 42 pages; v2. added refs, revised discussion of Bianchi for N
The magnetic fields of forming solar-like stars
Magnetic fields play a crucial role at all stages of the formation of low
mass stars and planetary systems. In the final stages, in particular, they
control the kinematics of in-falling gas from circumstellar discs, and the
launching and collimation of spectacular outflows. The magnetic coupling with
the disc is thought to influence the rotational evolution of the star, while
magnetised stellar winds control the braking of more evolved stars and may
influence the migration of planets. Magnetic reconnection events trigger
energetic flares which irradiate circumstellar discs with high energy particles
that influence the disc chemistry and set the initial conditions for planet
formation. However, it is only in the past few years that the current
generation of optical spectropolarimeters have allowed the magnetic fields of
forming solar-like stars to be probed in unprecedented detail. In order to do
justice to the recent extensive observational programs new theoretical models
are being developed that incorporate magnetic fields with an observed degree of
complexity. In this review we draw together disparate results from the
classical electromagnetism, molecular physics/chemistry, and the geophysics
literature, and demonstrate how they can be adapted to construct models of the
large scale magnetospheres of stars and planets. We conclude by examining how
the incorporation of multipolar magnetic fields into new theoretical models
will drive future progress in the field through the elucidation of several
observational conundrums.Comment: 55 pages, review article accepted for publication in Reports on
Progress in Physics. Astro-ph version includes additional appendice
Integration of tools for the Design and Assessment of High-Performance, Highly Reliable Computing Systems (DAHPHRS), phase 1
Systems for Space Defense Initiative (SDI) space applications typically require both high performance and very high reliability. These requirements present the systems engineer evaluating such systems with the extremely difficult problem of conducting performance and reliability trade-offs over large design spaces. A controlled development process supported by appropriate automated tools must be used to assure that the system will meet design objectives. This report describes an investigation of methods, tools, and techniques necessary to support performance and reliability modeling for SDI systems development. Models of the JPL Hypercubes, the Encore Multimax, and the C.S. Draper Lab Fault-Tolerant Parallel Processor (FTPP) parallel-computing architectures using candidate SDI weapons-to-target assignment algorithms as workloads were built and analyzed as a means of identifying the necessary system models, how the models interact, and what experiments and analyses should be performed. As a result of this effort, weaknesses in the existing methods and tools were revealed and capabilities that will be required for both individual tools and an integrated toolset were identified
TMCalc - A fast code to derive Teff and [Fe/H] for FGK stars
We present a new direct spectroscopic calibration for a fast estimation of
the stellar metallicity [Fe/H]. These calibrations were computed using a large
sample of 451 solar-type stars for which we have precise spectroscopic
parameters derived from high quality spectra. The new [Fe/H] calibration is
based on weak Fe I lines, which are expected to be less dependent on surface
gravity and microturbulence, and require only a pre-determination of the
effective temperature. This temperature can be obtained using a previously
presented line-ratio calibration. We also present a simple code that uses the
calibrations and procedures presented in these works to obtain both the
effective temperature and the [Fe/H] estimate. The code, written in C, is
freely available for the community and may be used as an extension of the ARES
code. We test these calibrations for 582 independent FGK stars. We show that
the code can be used as a precise and fast indicator of the spectroscopic
temperature and metallicity for dwarf FKG stars with effective temperatures
ranging from 4500 K to 6500 K and with [Fe/H] ranging from -0.8 dex to 0.4 dex.Comment: 10 pages, 8 Figures, published in A&
Functional specialization of the yeast Rho1 GTP exchange factors
Rho GTPases are regulated in complex spatiotemporal patterns that may be dependent, in part at least, on the multiplicity of their GTP exchange factors (GEFs). Here, we examine the extent of and basis for functional specialization of the Rom2 and Tus1 GEFs that activate the yeast Rho1 GTPase, the ortholog of mammalian RhoA. First, we find that these GEFs selectively activate different Rho1-effector branches. Second, the synthetic genetic networks around ROM2 and TUS1 confirm very different global in vivo roles for these GEFs. Third, the GEFs are not functionally interchangeable: Tus1 cannot replace the essential role of Rom2, even when overexpressed. Fourth, we find that Rom2 and Tus1 localize differently: Rom2 to the growing bud surface and to the bud neck at cytokinesis; Tus1 only to the bud neck but in a distinct pattern. Finally, we find that these GEFs are dependent on different protein co-factors: Rom2 function and localization is largely dependent on Ack1, a SEL1 domain containing protein; Tus1 function and localization is largely dependent on the Tus1-interacting protein Ypl066w (which we name Rgl1). We have revealed a surprising level of diversity among the Rho1 GEFs that contributes another level of complexity to the spatiotemporal control of Rho1
The B_s and D_s decay constants in 3 flavor lattice QCD
Capitalizing on recent advances in lattice QCD, we present a calculation of
the leptonic decay constants f_{B_s} and f_{D_s} that includes effects of one
strange sea quark and two light sea quarks. The discretization errors of
improved staggered fermion actions are small enough to simulate with 3
dynamical flavors on lattices with spacings around 0.1 fm using present
computer resources. By shedding the quenched approximation and the associated
lattice scale ambiguity, lattice QCD greatly increases its predictive power.
NRQCD is used to simulate heavy quarks with masses between 1.5 m_c and m_b. We
arrive at the following results: f_{B_s} = 260 \pm 7 \pm 26 \pm 8 \pm 5 MeV and
f_{D_s} = 290 \pm 20 \pm 29 \pm 29 \pm 6 MeV. The first quoted error is the
statistical uncertainty, and the rest estimate the sizes of higher order terms
neglected in this calculation. All of these uncertainties are systematically
improvable by including another order in the weak coupling expansion, the
nonrelativistic expansion, or the Symanzik improvement program.Comment: 4 page
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