1,171 research outputs found
Competition and Innovation: Evidence from Financial Services
In this paper we seek to contribute to the literature on competition and innovation by focusing on individual firms within the U.S. banking industry in the period 1984-2004. We measure innovation by estimating technology gaps and find evidence of an inverted-U relationship between competition and the technology gaps in banking. This finding is robust over several different specifications and is consistent with theoretical and empirical work by Aghion, Bloom, Blundell, Griffith, and Howitt (2005b). The optimal amount of innovation requires a slightly positive mark up. Also, we find that the U.S. banking industry as a whole has consolidated beyond this optimal innovation level and that state-level interstate banking deregulation has lowered innovation.competition, innovation, stochastic frontier analysis, technology gap ratio, banking
Diving behaviour of whale sharks in relation to a predictable food pulse
We present diving data for four whale sharks in relation to a predictable food pulse (reef fish spawn) and an analysis of the longest continuous fine-resolution diving record for a planktivorous shark. Fine-resolution pressure data from a recovered pop-up archival satellite tag deployed for 206 days on a whale shark were analysed using the fast Fourier Transform method for frequency domain analysis of time-series. The results demonstrated that a free-ranging whale shark displays ultradian, diel and circa-lunar rhythmicity of diving behaviour. Whale sharks dive to over 979.5 m and can tolerate a temperature range of 26.4 degrees C. The whale sharks made primarily diurnal deep dives and remained in relatively shallow waters at night. Whale shark diving patterns are influenced by a seasonally predictable food source, with shallower dives made during fish spawning periods
The management of tree genetic resources and the livelihoods of rural communities in the tropics: non-timber forest products, smallholder agroforestry practices and tree commodity crops
Products and services provided by trees in forests and farmland support the needs and promote the wellbeing of hundreds of millions of people in the tropics. Value depends on managing both the diversity of tree species present in landscapes and the genetic variation within these species. The benefits from trees and their genetic resources are, however, often not well quantified because trade is frequently outside formal markets, there is a multiplicity of species and ways in which trees are used and managed, and genetic diversity within species is frequently not given proper consideration. We review here what is known about the value of trees to rural communities through considering three production categories: non-timber products harvested from trees in natural and managed forests and woodlands; the various products and services obtained from a wide range of trees planted and/or retained in smallholders’ agroforestry systems; and the commercial products harvested from cultivated tree commodity crops. Where possible, we focus on the role of intra-specific genetic variation in providing support to livelihoods, and for each of the three production categories we also consider wider conservation and sustainability issues, including the linkages between categories in terms of management. Challenges to ‘conventional wisdom’ on tree resource use, value and management – such as in the posited links between commercialisation, cultivation and conservation – are highlighted, and constraints and opportunities to maintain and enhance value are described
Is Cycle 24 the Beginning of a Dalton-Like Minimum?
The unexpected development of cycle 24 emphasizes the need for a better way
to model future solar activity. In this article, we analyze the accumulation of
spotless days during individual cycles from 1798-2010. The analysis shows that
spotless days do not disappear abruptly in the transition towards an active
sun. A comparison with past cycles indicates that the ongoing accumulation of
spotless days is comparable to that of cycle 5 near the Dalton minimum and to
that of cycles 12, 14 and 15. It also suggests that the ongoing cycle has as
much as 20 \pm 8 spotless days left, from July 2010, before it reaches the next
solar maximum. The last spotless day is predicted to be in December 2012, with
an uncertainty of 11 months. This trend may serve as input to the solar dynamo
theories.Comment: 10 pages, 5 figures. The final publication is available at
http://www.springerlink.co
Is There Really a de Sitter/CFT Duality
In this paper a de Sitter Space version of Black Hole Complementarity is
formulated which states that an observer in de Sitter Space describes the
surrounding space as a sealed finite temperature cavity bounded by a horizon
which allows no loss of information. We then discuss the implications of this
for the existence of boundary correlators in the hypothesized dS/cft
correspondence. We find that dS complementarity precludes the existence of the
appropriate limits. We find that the limits exist only in approximations in
which the entropy of the de Sitter Space is infinite. The reason that the
correlators exist in quantum field theory in the de Sitter Space background is
traced to the fact that horizon entropy is infinite in QFT.Comment: 12 Figures, STIAS Workshop on Quantum Gravit
Asymptotic gluing of asymptotically hyperbolic solutions to the Einstein constraint equations
We show that asymptotically hyperbolic solutions of the Einstein constraint
equations with constant mean curvature can be glued in such a way that their
asymptotic regions are connected.Comment: 37 pages; 2 figure
Early stage morphology of quench condensed Ag, Pb and Pb/Ag hybrid films
Scanning Tunneling Microscopy (STM) has been used to study the morphology of
Ag, Pb and Pb/Ag bilayer films fabricated by quench condensation of the
elements onto cold (T=77K), inert and atomically flat Highly Oriented Pyrolytic
Graphite (HOPG) substrates. All films are thinner than 10 nm and show a
granular structure that is consistent with earlier studies of QC films. The
average lateral diameter, , of the Ag grains, however, depends on
whether the Ag is deposited directly on HOPG ( = 13 nm) or on a Pb
film consisting of a single layer of Pb grains ( = 26.8 nm). In
addition, the critical thickness for electrical conduction () of Pb/Ag
films on inert glass substrates is substantially larger than for pure Ag films.
These results are evidence that the structure of the underlying substrate
exerts an influence on the size of the grains in QC films. We propose a
qualitative explanation for this previously unencountered phenomenon.Comment: 11 pages, 3 figures and one tabl
Effect of GaN surface treatment on Al2O3/n-GaN MOS capacitors
Citation: Hossain, T., Wei, D., Edgar, J. H., Garces, N. Y., Nepal, N., Hite, J. K., . . . Meyer H.M, III. (2015). Effect of GaN surface treatment on Al2O3/n-GaN MOS capacitors. Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics, 33(6). doi:10.1116/1.4931793The surface preparation for depositing Al2O3 for fabricating Au/Ni/Al2O3/n-GaN (0001) metal oxide semiconductor (MOS) capacitors was optimized as a step toward realization of high performance GaN MOSFETs. The GaN surface treatments studied included cleaning with piranha (H2O2:H2SO4 = 1:5), (NH4)2S, and 30% HF etches. By several metrics, the MOS capacitor with the piranha-etched GaN had the best characteristics. It had the lowest capacitance–voltage hysteresis, the smoothest Al2O3 surface as determined by atomic force microscopy (0.2 nm surface roughness), the lowest carbon concentration (∼0.78%) at the Al2O3/n-GaN interface (from x-ray photoelectron spectroscopy), and the lowest oxide-trap charge (QT = 1.6 × 1011 cm−2eV−1). Its interface trap density (Dit = 3.7 × 1012 cm−2eV−1), as measured with photon-assisted capacitance– voltage method, was the lowest from conduction band-edge to midgap
Topological susceptibility with the improved Asqtad action
As a test of the chiral properties of the improved Asqtad (staggered fermion)
action, we have been measuring the topological susceptibility as a function of
quark masses for 2 + 1 dynamical flavors. We report preliminary results, which
show reasonable agreement with leading order chiral perturbation theory for
lattice spacing less than 0.1 fm. The total topological charge, however, shows
strong persistence over Monte Carlo time.Comment: Lattice2002(algor
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