6,807 research outputs found
Export versus FDI in german manufacturing: firm performance and participation in International markets.
Manufacturing; Firm performance; Performance; Participation; International; International markets; Markets; Market;
Scalar leptoquarks and the rare B meson decays
We study some rare decays of meson involving the quark level transition
in the scalar leptoquark model. We constrain the
leptoquark parameter space using the recently measured branching ratios of
processes. Using such parameters, we obtain the
branching ratios, direct CP violation parameters and isospin asymmetries in and processes. We also obtain the
branching ratios for some lepton flavour violating decays .
We find that the various anomalies associated with the isospin asymmetries of
process can be explained in the scalar leptoquark model.Comment: 28 pages, 7 figures. typos corrected, to appear in Phys. Rev.
Phylogenetic analysis of fungal ABC transporters
Background: The superfamily of ABC proteins is among the largest known in nature. Its members are mainly, but not exclusively, involved in the transport of a broad range of substrates across biological membranes. Many contribute to multidrug resistance in microbial pathogens and cancer cells. The diversity of ABC proteins in fungi is comparable with those in multicellular animals, but so far fungal ABC proteins have barely been studied.
Results: We performed a phylogenetic analysis of the ABC proteins extracted from the genomes of 27 fungal species from 18 orders representing 5 fungal phyla thereby covering the most important groups. Our analysis demonstrated that some of the subfamilies of ABC proteins remained highly conserved in fungi, while others have undergone a remarkable group-specific diversification. Members of the various fungal phyla also differed significantly in the number of ABC proteins found in their genomes, which is especially reduced in the yeast S. cerevisiae and S. pombe.
Conclusions: Data obtained during our analysis should contribute to a better understanding of the diversity of the fungal ABC proteins and provide important clues about their possible biological functions.
Ocean acidification and the loss of phenolic substances in marine plants.
Rising atmospheric CO(2) often triggers the production of plant phenolics, including many that serve as herbivore deterrents, digestion reducers, antimicrobials, or ultraviolet sunscreens. Such responses are predicted by popular models of plant defense, especially resource availability models which link carbon availability to phenolic biosynthesis. CO(2) availability is also increasing in the oceans, where anthropogenic emissions cause ocean acidification, decreasing seawater pH and shifting the carbonate system towards further CO(2) enrichment. Such conditions tend to increase seagrass productivity but may also increase rates of grazing on these marine plants. Here we show that high CO(2) / low pH conditions of OA decrease, rather than increase, concentrations of phenolic protective substances in seagrasses and eurysaline marine plants. We observed a loss of simple and polymeric phenolics in the seagrass Cymodocea nodosa near a volcanic CO(2) vent on the Island of Vulcano, Italy, where pH values decreased from 8.1 to 7.3 and pCO(2) concentrations increased ten-fold. We observed similar responses in two estuarine species, Ruppia maritima and Potamogeton perfoliatus, in in situ Free-Ocean-Carbon-Enrichment experiments conducted in tributaries of the Chesapeake Bay, USA. These responses are strikingly different than those exhibited by terrestrial plants. The loss of phenolic substances may explain the higher-than-usual rates of grazing observed near undersea CO(2) vents and suggests that ocean acidification may alter coastal carbon fluxes by affecting rates of decomposition, grazing, and disease. Our observations temper recent predictions that seagrasses would necessarily be "winners" in a high CO(2) world
Ultrashort pulse lossless propagation through a degenerate three-level medium in nonlinear optical waveguides and semiconductor microcavities
Published versio
In vitro effect of fluoride oral hygiene tablets on artificial caries lesion formation and remineralization in human enamel
<p>Abstract</p> <p>Background</p> <p>Aim of this <it>in-vitro</it>-study was to assess the remineralization potential of a tooth cleaning tablet with different fluoride content.</p> <p>Methods</p> <p>Twenty three caries free impacted third molars were examined, enamel surfaces were wax coated leaving two 3 à 4 mm windows for exposure to demineralization/remineralization cycles. The teeth were randomly assigned to 4 groups of 5 control and 6 experimental teeth. Demineralization by standardised HEC-gel, pH 4.7 at 37°C for 72 h, was alternated by rinsing in remineralization solution, pH 7.0 at 37°C for 72 h, total challenge time 432 h. The negative control group N was treated during remineralization cycles with saline; positive control group P was treated with remineralization solution; experimental group D1 was exposed to remineralization solution containing Denttabs<sup>Ž</sup>-tablets with 1450 ppm F; experimental group D2 was exposed to remineralization solution and Denttabs<sup>Ž</sup>-tablets with 4350 ppm F. Each tooth was cut into serial sections and analyzed by polarized light microscopy for assessment of the different zones of white-spot lesions in 3 representative sections. Statistical analysis was based on the <it>Mann-Whitney</it>-Test.</p> <p>Results</p> <p>Both control groups N(-) and P(+) exhibited characteristic white-spot lesions. The remineralization and the demineralization inhibition of the lesions increased considerably from N<P < D1<D2. Denttabs<sup>Ž</sup>-2 administration showed partial/total remineralization including lamination and/or disappearance of the body of the lesion. The different results of all 4 groups were statistically highly significant (p < 0.01) with both tests.</p> <p>Conclusion</p> <p>Based on these results the novel Denttabs<sup>Ž </sup>formulation represents a highly effective oral hygiene product and the remineralization is correlated to the fluoride content.</p
Revisit Sparse Polynomial Interpolation based on Randomized Kronecker Substitution
In this paper, a new reduction based interpolation algorithm for black-box
multivariate polynomials over finite fields is given. The method is based on
two main ingredients. A new Monte Carlo method is given to reduce black-box
multivariate polynomial interpolation to black-box univariate polynomial
interpolation over any ring. The reduction algorithm leads to multivariate
interpolation algorithms with better or the same complexities most cases when
combining with various univariate interpolation algorithms. We also propose a
modified univariate Ben-or and Tiwarri algorithm over the finite field, which
has better total complexity than the Lagrange interpolation algorithm.
Combining our reduction method and the modified univariate Ben-or and Tiwarri
algorithm, we give a Monte Carlo multivariate interpolation algorithm, which
has better total complexity in most cases for sparse interpolation of black-box
polynomial over finite fields
Effects of music and music-video on core affect during exercise at the lactate threshold
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordThe objective of the present study was to examine the effects of music and music-video on core affect during and immediately after stationary cycling at the lactate threshold. A randomized, fully counterbalanced, crossover design with three conditions (music, music-video, and a no-music-video control) was adopted. Twenty-four participants exercised at lactate threshold while exposed to music, music-video, and control conditions. Affective valence and perceived activation were assessed every 2 min during a 20-min exercise bout and every 5 min post exercise over a 20-min period. Results indicated that there was a significant condition x time interaction for affective valence. The music-video condition elicited the highest levels of affective valence followed by the music condition and control. There was a main effect of condition for affective valence, wherein the experimental conditions facilitated significantly higher affective valence than control. Significant main effects of time emerged for both affective valence and perceived activation. Regardless of condition, affective valence decreased during the exercise bout and increased immediately post exercise. Conversely, perceived activation increased during exercise and decreased immediately post exercise. The present findings indicate that music and music-video can enhance core affect during exercise at the lactate threshold and the implications for exercise adherence are expounded
Spin-glass behavior in KxRu4-yNiyO8 hollandite materials
We report the synthesis and comprehensive ac and dc susceptibility measurements of KxRu4âyNiyO8 hollandite. The value of the relative frequency shift, δTf , has been determined as 0.025 which is within the range expected for spin-glass systems (0.005â0.06). Additionally, the characteristic flipping time of a single spin flip, Ď0, and the dynamical critical exponent, âzv, were determined to have values of 5.82Ă10â8 s and 6.1(3), respectively from the power law. While the value of Ď0 is comparatively very large, âzv is consistent with what is expected for spin-glass systems. Field-cooled hysteresis behavior demonstrates a small increase in the remnant magnetization (at 2 K) on increasing the strength of the cooling field, suggesting that the degree of short-range correlations increases consistent with the formation of larger spin clusters. Thermoremnant magnetization data indicate an exponential-like decay of the magnetization as a function of time with the remnant magnetization remaining nonzero. However, it is clear from these data that multiple components contribute to the decay behavior. Collectively, these data confirm spin-glass character for K0.73(3)Ni1.9(5)Ru2.1(5)O8 and clearly demonstrate that the magnetic behavior of this material is far from simplistic
The Sphaleron Rate in SU(N) Gauge Theory
The sphaleron rate is defined as the diffusion constant for topological
number NCS = int g^2 F Fdual/32 pi^2. It establishes the rate of equilibration
of axial light quark number in QCD and is of interest both in electroweak
baryogenesis and possibly in heavy ion collisions. We calculate the
weak-coupling behavior of the SU(3) sphaleron rate, as well as making the most
sensible extrapolation towards intermediate coupling which we can. We also
study the behavior of the sphaleron rate at weak coupling at large Nc.Comment: 18 pages with 3 figure
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