2,396 research outputs found
Generation of femtosecond light pulses in the near infrared around λ = 850 nm
Femtosecond light pulses tunable between 840 nm and 880 nm are generated in a synchronously pumped ring dye laser. The laser emits nearly bandwidth-limited pulses (Δv tp = 0.45) with pulse durations down to 65 fs. At a pumping power of 450 mW of a mode-locked Ar-ion laser (λ = 514 nm) the infrared femtosecond dye laser has an output of up to 15 mW
Prevalent Behavior of Strongly Order Preserving Semiflows
Classical results in the theory of monotone semiflows give sufficient
conditions for the generic solution to converge toward an equilibrium or
towards the set of equilibria (quasiconvergence). In this paper, we provide new
formulations of these results in terms of the measure-theoretic notion of
prevalence. For monotone reaction-diffusion systems with Neumann boundary
conditions on convex domains, we show that the set of continuous initial data
corresponding to solutions that converge to a spatially homogeneous equilibrium
is prevalent. We also extend a previous generic convergence result to allow its
use on Sobolev spaces. Careful attention is given to the measurability of the
various sets involved.Comment: 18 page
Seeding Occupational Therapy in Cambodia, Laos, Myanmar and Vietnam - a Collaborative Approach of On-line Education
Phylogenetics of Archerfishes (Toxotidae) and Evolution of the Toxotid Shooting Apparatus
A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Archerfishes (Toxotidae) are variously found in the fresh- and brackish-water environments of Asia Pacific and are well known for their ability to shoot water at terrestrial prey. These shots of water are intended to strike their prey and cause it to fall into the water for capture and consumption. While this behavior is well known, there are competing hypotheses (blowpipe vs. pressure tank hypothesis) of how archerfishes shoot and which oral structures are involved. Current understanding of archerfish shooting structures is largely based on two species, Toxotes chatareus and T. jaculatrix. We do not know if all archerfishes possess the same oral structures to shoot water, if anatomical variation is present within these oral structures, or how these features have evolved. Additionally, there is little information on the evolution of the Toxotidae as a whole, with all previous systematic works focusing on the interrelationships of the family. We first investigate the limits of archerfish species using new and previously published genetic data. Our analyses highlight that the current taxonomy of archerfishes does not conform to the relationships we recover. Toxotes mekongensis and T. siamensis are placed in the synonymy of T. chatareus, Toxotes carpentariensis is recognized as a species and removed from the synonymy of T. chatareus, and the genus Protoxotes is recognized for T. lorentzi based on the results of our analyses. We then take an integrative approach, using a combined analysis of discrete hard- and soft-tissue morphological characters with genetic data, to construct a phylogeny of the Toxotidae. Using the resulting phylogenetic hypothesis, we then characterize the evolutionary history and anatomical variation within the archerfishes. We discuss variation in the oral structures and the evolution of the mechanism with respect to the interrelationships of archerfishes, and find that the oral structures of archerfishes support the blowpipe hypothesis but soft-tissue oral structures may also play a role in shooting. Finally, by comparing the morphology of archerfishes to their sister group, we find that the Leptobramidae has relevant shooting features in the oral cavity, suggesting that some components of the archerfish shooting mechanism are examples of co-opted or exapted traits
WIMPs search by scintillators: possible strategy for annual modulation search with large-mass highly-radiopure NaI(Tl)
The DAMA experiments are running deep underground in the Gran Sasso National
Laboratory. Several interesting results have been achieved so far. Here a
maximum likelihood method to search for the WIMP annual modulation signature is
discussed and applied to a set of preliminary test data collected with large
mass highly radiopure NaI(Tl) detectors. Various related technical arguments
are briefly addressed.Comment: 6 pages, 4 figures, LaTex. Contributed paper to TAUP97; to appear in
the Proceeding
'Parasitic invasions' or sources of good governance: constraining foreign competition in Hong Kong banking, 1956-81
This paper investigates the operation and impact of the moratorium on new banking licences imposed in Hong Kong in 1965 and the claims that foreign banks destabilised the banking system and drained resources from the colony. First it examines foreign banks' attempts to circumvent the moratorium through claims of special circumstances and buying interests in local banks, and secondly it examines the efforts of incumbents to extend barriers to non-bank financial institutions and to branches of foreign banks. The general conclusions are that while the moratorium was aimed at increasing the stability of the banking system, it had the effect of decreasing the regulatory breadth of the government, and reducing incentives for mergers and acquisitions that might have improved governance
Phase transitions in BaTiO from first principles
We develop a first-principles scheme to study ferroelectric phase transitions
for perovskite compounds. We obtain an effective Hamiltonian which is fully
specified by first-principles ultra-soft pseudopotential calculations. This
approach is applied to BaTiO, and the resulting Hamiltonian is studied
using Monte Carlo simulations. The calculated phase sequence, transition
temperatures, latent heats, and spontaneous polarizations are all in good
agreement with experiment. The order-disorder vs.\ displacive character of the
transitions and the roles played by different interactions are discussed.Comment: 13 page
Corals Pocillopora eydouxi and Porites lobata (Anthozoa: Scleractinia).
v. ill. 23 cm.QuarterlyReciprocal transplant experiments of the corals Pocillopora eydouxi Milne Edwards & Haime and Porites lobata Dana were carried out for an 18- month period from September 2004 to March 2006 between two back reef pools on Ofu Island, American Samoa, to test environmental versus genetic effects on skeletal growth rates. Skeletal growth of P. eydouxi showed environmental but not genetic effects, resulting in doubling of growth in Pool 300 compared with Pool 400. There were no environmental or genetic effects on skeletal growth of P. lobata. Pool 300 had more frequent and longer durations of elevated seawater temperatures than Pool 400, characteristics likely to decrease rather than increase skeletal growth. Pool 300 also had higher nutrient levels and flow velocities than Pool 400, characteristics that may increase skeletal growth. However, higher nutrient levels would be expected to increase skeletal growth in both species, but there was no difference between the pools in P. lobata growth. P. eydouxi is much more common in high-energy environments than P. lobata; thus the higher flow velocities in Pool 300 than in Pool 400 may have positively affected skeletal growth of P. eydouxi while not having a detectable effect on P. lobata. The greater skeletal growth of P. eydouxi in Pool 300 occurred despite the presence of clade D zooxanthellae in several source colonies in Pool 300, a genotype known to result in greater heat resistance but slower skeletal growth. Increased skeletal growth rates in higher water motion may provide P. eydouxi a competitive advantage in shallow, high-energy environments where competition for space is intense
The long-term agronomic and economic effects of crop rotations in western Canada
Non-Peer ReviewedAgriculture Canada Research Stations in western Canada have conducted more than 68 long-term crop rotation experiments since the early 1900's; twenty of these are still ongoing. A committee of scientists, representing all Research Stations on the Prairies has just completed an in-depth review and summary of the major findings from these studies. Based on their findings, they also developed recommendations that can be used by managers in decision making and rationalization of resource use for current and future
studies of this kind. The resulting two publications which will be released in early 1990 include: i) a bulletin entitled 'Benefits of Crop Rotation for Sustainable Agriculture in Dryland Farming', 'Which presents producer recommendations on how to run an efficient, economical, and environmentally responsible cropping operation, and ii) a detailed technical book entitled 'Crop Rotation Studies on the Canadian Prairies', which is directed at the scientific community but is also useful for extension personnel and producers. This paper highlights some of the main aspects reported in these publications and attempts to give a coherent and broader interpretation of the underlying principles and processes of crop production. The discussion focuses on the effects of rotation length, crop sequence, substitutes for summerfallow, and N and P fertilizer, on crop production, grain and forage quality, soil moisture conservation and moisture use efficiency, N and P uptake by the plants, nutrient losses, soil quality, profitability, nonrenewable energy efficiency, and crop pests
Differential Thermal Analysis of Commercial and Dental Waxes
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67104/2/10.1177_00220345670460051701.pd
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