Analytic Reconstruction of heavy-quark two-point functions at O(\alpha_s^3)

Using a method previously developed, based on the Mellin-Barnes transform, we reconstruct the two-point correlators in the vector, axial, scalar and pseudoscalar channels from the Taylor expansion at q^2=0, the threshold expansion at q^2=4m^2 and the OPE at q^2\rightarrow -\infty, where m is the heavy quark mass. The reconstruction is analytic and systematic and is controlled by an error function which becomes smaller as more terms in those expansions are known.Comment: 19 pages, 11 figure

Pancreaticoduodenal transplantation in humans

Whole cadaveric pancreata were transplanted to the pelvic extraperitoneal location in four patients with diabetes who previously had undergone successful cadaveric renal transplantation. One graft was lost within a few hours from venous thrombosis but with patient survival. The other three are providing normal endocrine function after two and a half, 11 and 12 months. The exocrine pancreatic secretions were drained into the recipient jejunum through enteric anastomoses. Because mucosal slough of the graft and duodenum and jejunum in two patients caused a protein losing enteropathy and necessitated reoperations, we now do the pancreatic transplantation with only a blister of graft duodenum large enough for side-to-side enteroenterostomy. The spleen has been transplanted with the pancreas mainly for technical reasons, and this technique should have further trials in spite of the fact that delayed graft splenectomy became necessary in two recipients to treat graft induced hematologic complications

Spatiotemporal Chaos, Localized Structures and Synchronization in the Vector Complex Ginzburg-Landau Equation

We study the spatiotemporal dynamics, in one and two spatial dimensions, of two complex fields which are the two components of a vector field satisfying a vector form of the complex Ginzburg-Landau equation. We find synchronization and generalized synchronization of the spatiotemporally chaotic dynamics. The two kinds of synchronization can coexist simultaneously in different regions of the space, and they are mediated by localized structures. A quantitative characterization of the degree of synchronization is given in terms of mutual information measures.Comment: 6 pages, using bifchaos.sty (included). 7 figures. Related material, including higher quality figures, could be found at http://www.imedea.uib.es/PhysDept/publicationsDB/date.html . To appear in International Journal of Bifurcation and Chaos (1999

Cell size distribution in a random tessellation of space governed by the Kolmogorov-Johnson-Mehl-Avrami model: Grain size distribution in crystallization

The space subdivision in cells resulting from a process of random nucleation and growth is a subject of interest in many scientific fields. In this paper, we deduce the expected value and variance of these distributions while assuming that the space subdivision process is in accordance with the premises of the Kolmogorov-Johnson-Mehl-Avrami model. We have not imposed restrictions on the time dependency of nucleation and growth rates. We have also developed an approximate analytical cell size probability density function. Finally, we have applied our approach to the distributions resulting from solid phase crystallization under isochronal heating conditions

Sediment transport processes at the head of Halibut Canyon, Eastern Canada margin: An interplay between internal tides and dense shelf water cascading

European Geosciences Union General Assembly 2013, 7-12 April, Vienna, Austria.-- 1 pageTo investigate the processes by which sediment is transported through a submarine canyon incised in a glaciated margin, the bottom boundary layer quadrapod RALPH was deployed at 276-m depth in the West Halibut Canyon (off Newfoundland) during winter 2008–2009. Two main sediment transport processes were identified throughout the deployment. Firstly, periodic increases of near-bottom suspended-sediment concentrations (SSC) were recorded associated with the up-canyon propagation of the semidiurnal internal tidal bore along the canyon axis, carrying fine sediment particles resuspended from deeper canyon regions. The recorded SSC peaks, lasting less than 1 h, were observed sporadically and were linked to bottom intensified up-canyon flows (~ 40 cm s− 1) concomitant with sharp drops in temperature. Secondly, sediment transport was also observed during events of intensified down-canyon current velocities that occurred during periods of sustained heat loss from surface waters, but were not associated with large storm waves. High-resolution velocity profiles throughout the water column during these events revealed that the highest current speeds (~ 1 m s− 1) were centered several meters above the sea floor and corresponded to the region of maximum velocities of a gravity flow. Such flows had associated low SSC and cold water temperatures and are interpreted as dense shelf water cascading events channelized along the canyon axis. Sediment transport during these events was largely restricted to bedload and saltation, producing winnowing of sands and fine sediments around larger gravel particles. Analysis of historical hydrographic data suggests that such gravity flows are not related to the formation of coastal dense waters advected towards the outer shelf that reached the canyon head. Rather, the dense shelf waters appear to be generated around the outer shelf, where convection during winter is able to reach the sea floor and generate a pool of near-bottom dense water that cascades into the canyon during one or two tidal cycles. A similar transport mechanism is likely to occur in other submarine canyons along the eastern Canadian margin, as well in other canyoned margins where winter convection can reach the shelf-edgePeer Reviewe

Effects of a localized beam on the dynamics of excitable cavity solitons

We study the dynamical behavior of dissipative solitons in an optical cavity filled with a Kerr medium when a localized beam is applied on top of the homogeneous pumping. In particular, we report on the excitability regime that cavity solitons exhibits which is emergent property since the system is not locally excitable. The resulting scenario differs in an important way from the case of a purely homogeneous pump and now two different excitable regimes, both Class I, are shown. The whole scenario is presented and discussed, showing that it is organized by three codimension-2 points. Moreover, the localized beam can be used to control important features, such as the excitable threshold, improving the possibilities for the experimental observation of this phenomenon.Comment: 9 Pages, 12 figure