247 research outputs found
Quality of life and anorectal malformations: a single-center experience
Purpose: The treatment and long term clinical outcomes of anorectal malformations (ARM) in children have always been the focus of pediatric surgeons. This study aimed at reporting our experience as far as long-term follow-up of ARM in children is concern. Methods: We enrolled patients treated between 1999 and 2019, and established selection criteria to choose appropriate subjects. A validated questionnaire was used to determine long-term quality of life outcomes. Results: Out of a total of 48 patients treated within the study period, 28 were enrolled in this study. Among the latter, more than 35% had at least one long-time complication, and more than 90% had a good lifestyle. Urinary and fecal continence was achieved in more than 95% of the patients using medical devices. Conclusion: This study aimed to bring up new concepts; taking into consideration all aspects of life in patients with ARM, from school life to sexuality, while evaluating fecal and urinary continence. This is essential for the improvement of the skills of the different specialists involved in the management of these patients, and for the implementation of strategies that can improve postoperative function. Most especially, it will also help improve communication between doctors to ensure an adequate transition of these children into adult life
Gravity of higher-dimensional global defects
Solutions of Einstein's equations are found for global defects in a
higher-dimensional spacetime with a nonzero cosmological constant Lambda. The
defect has a (p-1)-dimensional core (brane) and a `hedgehog' scalar field
configuration in the n extra dimensions. For Lambda = 0 and n > 2, the
solutions are characterized by a flat brane worldsheet and a solid angle
deficit in the extra dimensions. For Lambda > 0, one class of solutions
describes spherical branes in an inflating higher-dimensional universe.
Instantons obtained by a Euclidean continuation of such solutions describe
quantum nucleation of the entire inflating brane-world, or of a spherical brane
in an inflating higher-dimensional universe. For Lambda < 0, one class of
solutions exhibits an exponential warp factor. It is similar to spacetimes
previously discussed by Randall and Sundrum for n = 1 and by Gregory for n = 2.Comment: 18 pages, no figures, uses revte
Semiclassical Quantization by Pade Approximant to Periodic Orbit Sums
Periodic orbit quantization requires an analytic continuation of
non-convergent semiclassical trace formulae. We propose a method for
semiclassical quantization based upon the Pade approximant to the periodic
orbit sums. The Pade approximant allows the re-summation of the typically
exponentially divergent periodic orbit terms. The technique does not depend on
the existence of a symbolic dynamics and can be applied to both bound and open
systems. Numerical results are presented for two different systems with chaotic
and regular classical dynamics, viz. the three-disk scattering system and the
circle billiard.Comment: 7 pages, 3 figures, submitted to Europhys. Let
Nonsingular global string compactifications
We consider an exotic `compactification' of spacetime in which there are two
infinite extra dimensions, using a global string instead of a domain wall. By
having a negative cosmological constant we prove the existence of a nonsingular
static solution using a dynamical systems argument. A nonsingular solution also
exists in the absence of a cosmological constant with a time-dependent metric.
We compare and contrast this solution with the Randall-Sundrum universe and the
Cohen-Kaplan spacetime, and consider the options of using such a model as a
realistic resolution of the hierarchy problem.Comment: 8 pages revtex, 1 figure : References added and equation correcte
Targeting gemcitabine containing liposomes to CD44 expressing pancreatic adenocarcinoma cells causes an increase in the antitumoral activity
A methane seep area in the Skagerrak, the habitat of the pogonophore Siboglinum poseidoni and the bivalve mollusc Thyasira sarsi
The effect of parallel static and microwave electric fields on excited hydrogen atoms
Motivated by recent experiments we analyse the classical dynamics of a
hydrogen atom in parallel static and microwave electric fields. Using an
appropriate representation and averaging approximations we show that resonant
ionisation is controlled by a separatrix, and provide necessary conditions for
a dynamical resonance to affect the ionisation probability.
The position of the dynamical resonance is computed using a high-order
perturbation series, and estimate its radius of convergence. We show that the
position of the dynamical resonance does not coincide precisely with the
ionisation maxima, and that the field switch-on time can dramatically affect
the ionisation signal which, for long switch times, reflects the shape of an
incipient homoclinic. Similarly, the resonance ionisation time can reflect the
time-scale of the separatrix motion, which is therefore longer than
conventional static field Stark ionisation. We explain why these effects should
be observed in the quantum dynamics.
PACs: 32.80.Rm, 33.40.+f, 34.10.+x, 05.45.Ac, 05.45.MtComment: 47 pages, 20 figure
Meloneis Gen. Nov., a New Epipsammic Genus of Rhaphoneidaceae (Bacillariophyceae)
The diatom family Rhaphoneidaceae is characterized by high generic diversity and low species diversity with most genera known to have long stratigraphic ranges. The genera within this family are neritic marine, and mostly epipsammic. A new modern and epipsammic genus, Meloneis gen. nov., is described herein and is compared to all genera within Rhaphoneidaceae and especially to Rhaphoneis Ehrenberg s.l. Within Meloneis three new species and one variety are distinguished and described herein: M. mimallis sp. nov., M. mimallis var. zephyria var. nov., M. akytos sp. nov., and M. gorgis sp. nov
Prediction of Low-Voltage Tetrafluoromethane Emissions Based on the Operating Conditions of an Aluminium Electrolysis Cell
Greenhouse gas (GHG) generation is inherent in the production of aluminium by a technology that uses carbon anodes. Most of those GHG are composed of CO2 produced by redox reaction that occurs in the cell. However, a significant fraction of the annual GHG production is composed of perfluorocarbons (PFC) resulting from anode effects (AE). Multiple investigations have shown that
tetrafluoromethane (CF4) can be generated under low-voltage conditions in the electrolysis cells, without global anode effect. The aim of this paper is to find a quantitative relationship between monitored cell parameters and the emissions of CF4. To achieve this goal, a predictive algorithm has been developed using seven cell indicators. These indicators are based on the cell voltage, the noise level and other parameters calculated from individual anode current monitoring. The predictive algorithm is structured into three different
steps. The first two steps give qualitative information while the third one quantitatively describes the expected CF4 concentration at the duct end of the electrolysis cells. Validations after each step are presented and discussed. Finally, a sensitivity analysis was performed to understand the effect of each indicator on the onset of low-voltage PFC emissions. The standard deviation of
individual anode currents was found to be the dominant variable. Cell voltage, noise level, and maximum individual anode current also showed a significant
correlation with the presence of CF4 in the output gas of an electrolysis cell
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