961 research outputs found

    Technical and Clinical Evolution of Modern Neuroendoscopy

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    The needle in the haystack - searching for genetic and epigenetic differences in monozygotic twins discordant for Tetralogy of Fallot

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    Congenital heart defects (CHDs) are the most common birth defect in human with an incidence of almost 1% of all live births. Most cases have a multifactorial origin with both genetics and the environment playing a role in its development and progression. Adding an epigenetic component to this aspect is exemplified by monozygotic twins which share the same genetic background but have a different disease status. As a result, the interplay between the genetic, epigenetic and the environmental conditions might contribute to the etiology and phenotype. To date, the underlying causes of the majority of CHDs remain poorly understood. In this study, we performed genome-wide high-throughput sequencing to examine the genetic, structural genomic and epigenetic differences of two identical twin pairs discordant for Tetralogy of Fallot (TOF), representing the most common cyanotic form of CHDs. Our results show the almost identical genetic and structural genomic identity of the twins. In contrast, several epigenetic alterations could be observed given by DNA methylation changes in regulatory regions of known cardiac-relevant genes. Overall, this study provides first insights into the impact of genetic and especially epigenetic factors underlying monozygotic twins discordant for CHD like TOF

    Long-Time Asymptotics for the Korteweg-de Vries Equation via Nonlinear Steepest Descent

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    We apply the method of nonlinear steepest descent to compute the long-time asymptotics of the Korteweg-de Vries equation for decaying initial data in the soliton and similarity region. This paper can be viewed as an expository introduction to this method.Comment: 31 page

    Magnetic trapping of metastable 3P2^3P_2 atomic strontium

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    We report the magnetic trapping of metastable 3P2^3P_2 atomic strontium. Atoms are cooled in a magneto-optical trap (MOT) operating on the dipole allowed 1S01P1^1S_0-^1P_1 transition at 461 nm. Decay via 1P11D23P2^1P_1\to {^1D_2}\to {^3P_2} continuously loads a magnetic trap formed by the quadrupole magnetic field of the MOT. Over 10810^8 atoms at a density of 8×1098 \times 10^9 cm3^{-3} and temperature of 1 mK are trapped. The atom temperature is significantly lower than what would be expected from the kinetic and potential energy of atoms as they are transferred from the MOT. This suggests that thermalization and evaporative cooling are occurring in the magnetic trap.Comment: This paper has been accepted by PR

    Long-Time Asymptotics of Perturbed Finite-Gap Korteweg-de Vries Solutions

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    We apply the method of nonlinear steepest descent to compute the long-time asymptotics of solutions of the Korteweg--de Vries equation which are decaying perturbations of a quasi-periodic finite-gap background solution. We compute a nonlinear dispersion relation and show that the x/tx/t plane splits into g+1g+1 soliton regions which are interlaced by g+1g+1 oscillatory regions, where g+1g+1 is the number of spectral gaps. In the soliton regions the solution is asymptotically given by a number of solitons travelling on top of finite-gap solutions which are in the same isospectral class as the background solution. In the oscillatory region the solution can be described by a modulated finite-gap solution plus a decaying dispersive tail. The modulation is given by phase transition on the isospectral torus and is, together with the dispersive tail, explicitly characterized in terms of Abelian integrals on the underlying hyperelliptic curve.Comment: 45 pages. arXiv admin note: substantial text overlap with arXiv:0705.034

    ProSA - Using the CHASE for Provenance Management

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    Collecting, storing, tracking, and archiving scientific data is the main task of research data management, being the basis for scientific evaluations. In addition to the evaluation (a complex query in the case of structured databases) and the result itself, the important part of the original database used has also to be archived. To ensure reproducible and replicable research, the evaluation queries can be processed again at a later point in time in order to reproduce the result. Being able to calculate the origin of an evaluation is the main problem in provenance management, particularly in why and how data provenance. We are developing a tool called ProSA which combines data provenance and schema/data evolution using the CHASE for the different database transformations needed. Besides describing the main ideas of ProSA, another focus of this paper is the concrete use of our CHASE tool ChaTEAU for invertible query evaluation

    Application of stochastic programming to reduce uncertainties in quality-based supply planning of slaughterhouses

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    To match products of different quality with end market preferences under supply uncertainty, it is crucial to integrate product quality information in logistics decision making. We present a case of this integration in a meat processing company that faces uncertainty in delivered livestock quality. We develop a stochastic programming model that exploits historical product quality delivery data to produce slaughterhouse allocation plans with reduced levels of uncertainty in received livestock quality. The allocation plans generated by this model fulfil demand for multiple quality features at separate slaughterhouses under prescribed service levels while minimizing transportation costs. We test the model on real world problem instances generated from a data set provided by an industrial partner. Results show that historical farmer delivery data can be used to reduce uncertainty in quality of animals to be delivered to slaughterhouses
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