413 research outputs found
Congenital myelomeningocele - do we have to change our management?
<p>Abstract</p> <p>Background</p> <p>Eagerly awaiting the results of the Management of Myelomeningocele Study (MOMS) and with an increasing interest in setting up intrauterine myelomeningocele repair (IUMR), the optimal management of patients suffering from congenital myelomeningocele (MMC) has become a matter of debate again. We performed a cross-sectional study at our referral-center for MMC to determine the outcome for our expectantly managed patients.</p> <p>Materials and methods</p> <p>A computed chart review at our institution revealed 70 patients suffering from MMC. Forty-three patients were eligible for the study and analyzed further. A retrospective analysis was performed only in patients that underwent MMC repair within the first two days of life and were seen at our outpatient clinic between 2008 and 2009 for a regular multidisciplinary follow-up. Data were collected on: gestational age (GA) and weight at birth, age at shunt placement and shunt status after the first year of life, radiological evidence for Arnold-Chiari malformation (ACM) and tethered cord (TC), need for surgery for TC, bladder function, lower leg function and educational level. Data were compared to published results for IUMR and to studies of historical controls.</p> <p>Results</p> <p>Patients were born with MMC between 1979 and 2009 and are now 13.3 ± 8.9 (mean ± SD) years of age. At birth, mean GA was 37.8 ± 2.3 weeks and mean weight was 2921.3 ± 760.3 g, both significantly higher than in IUMR patients. Shunt placement in our cohort was required in 69.8% at a mean age of 16.0 ± 10.7 days, which was less frequent than for historical controls. Amongst our cohort, radiological observations showed 57.1% had ACM II and 41.9% had TC. Only two of our patients underwent a surgical correction for TC. Clean intermittent catheterization was performed in 69.7% of our patients, 56.4% were (assisted) walkers and 64.1% attended regular classes, both comparable to historical controls.</p> <p>Conclusions</p> <p>With a close and interdisciplinary management by pediatric surgeons, neurologists and urologists, the long-term outcome of patients suffering from MMC can currently be considered satisfactory. With respect to the known drawbacks of fetal interventions for mother and child, especially preterm delivery, the results of the MOMS trial should be awaited with caution before proceeding with a complex intervention like IUMR.</p
An End-to-End Performance Comparison of Seven Permissioned Blockchain Systems
The emergence of more and more blockchain solutions with innovative
approaches to optimising performance, scalability, privacy and governance
complicates performance analysis. Reasons for the difficulty of benchmarking
blockchains include, for example, the high number of system parameters to
configure and the effort to deploy a blockchain network. In addition,
performance data, which mostly comes from system vendors, is often
intransparent. We investigate and evaluate the performance of seven
permissioned blockchain systems using different parameter settings in a
reproducible manner. We employ an end-to-end approach, where the clients
sending the transactions are fully involved in the data collection approach.
Our results highlight the peculiarities and limitations of the systems under
investigation. Due to the insights given, our work forms the basis for
continued research to optimise the performance of blockchain systems.Comment: 14 pages, 5 figures, 20 tables, Middleware Conferenc
Pre-competition cardiac screening in professional handball players - setting up at the EHF European Handball Championship 2010 in Austria
Zusammenfassung: In vielen Sportarten wird ein regelmĂ€Ăiges, richtliniengetreues kardiales Screening zur Verhinderung des plötzlichen Herztods noch immer nicht gewĂ€hrleistet. Wir nahmen die Handball Europameisterschaften, welche 2010 in Wien und weiteren StĂ€dten in Ăsterreich stattfanden, zum Anlass, die aktuelle Situation bei Toplevel-Handballern zu untersuchen: Ein standardisierter Fragebogen wurde vor dem Turnier an alle qualifizierten Teams und Spieler versandt. Eine RĂŒcklaufrate von 42,7 % kann zum Schluss fĂŒhren, dass das Problem des plötzlichen Herztods bei den Spielern und Verantwortlichen unterschĂ€tzt wird. Die ĂŒberwiegende Mehrzahl der Spieler (82 %) wurde gemÀà der Auswertung der Fragebögen korrekt, entsprechend der aktuellen Screening-Richtlinien untersucht. In gut der HĂ€lfte der Teams wurde das Screening jedoch "inhomogen" durchgefĂŒhrt. 5 Spieler (4,1 %) wurden zumindest nicht innerhalb der letzten Jahre untersucht, bei 1 Spieler (0,8 %) wurde kein EKG durchgefĂŒhrt. WĂ€hrend 69 % der Handballer ihr erstes Screening erst nach dem Alter von 18 Jahren durchliefen, wurden 16 Spieler (13,1 %) gar niemals zuvor einer kardialen Vorsorgeuntersuchung unterzogen. SchlieĂlich identifizierten wir aufgrund der Fragebögen 17 Athleten (13,9 %) mit einer hoch suspekten Anamnese, wovon 2 Athleten (1,6 %) niemals zuvor kardiologisch abgeklĂ€rt wurde
A fiber-based beam profiler for high-power laser beams in confined spaces and ultra-high vacuum
Laser beam profilometry is an important scientific task with well-established
solutions for beams propagating in air. It has, however, remained an open
challenge to measure beam profiles of high-power lasers in ultra-high vacuum
and in tightly confined spaces. Here we present a novel scheme that uses a
single multi-mode fiber to scatter light and guide it to a detector. The method
competes well with commercial systems in position resolution, can reach through
apertures smaller than ~m and is compatible with
ultra-high vacuum conditions. The scheme is simple, compact, reliable and can
withstand laser intensities beyond 2~MW/cm
Process Selection in RPA Projects â Towards a Quantifiable Method of Decision Making
The digital age requires companies to invest in value-creating rather than routine activities to drive innovation as a future source of competitiveness and business success. Thus, many companies are reluctant to invest in large-scale, costly backend integration projects and seek adaptable solutions to automate their front-office activities. Bridging artificial intelligence and business process management, robotic process automation (RPA) provides the promise of robots as a virtual workforce that performs these tasks in a self-determined manner. Many studies have highlighted potential benefits of RPA. However, little data is available on operationalizing and automating RPA to maximize its benefits. In this paper, we shed light on the automation potential of processes with RPA and operationalize it. Based on process mining techniques, we propose an automatable indicator system as well as present and evaluate decision support for companies that seek to better prioritize their RPA activities and to maximize their return on investment
Characterization and sorption properties of low pH cements
Characterization of three low pH cement pastes, including the description of their sorption properties for tritiated water (HTO), 36Cl- and 129I- is described in this work. SEM-EDX and NMR analyses show that after 90 days of hydration, the main hydrated phases are C-S-H and C-A-S-H gels with a Ca:Si ratio between 0.8 - 1.0 and a Al:Si ratio of 0.05. TG-DSC and XRD indicate the presence of calcite in the mixtures where limestone filler has been used. Additional techniques were used to identify minor hydrated solid phases like ettringite (i.e., XRD and solid state NMR). Porosity and pore size distribution was characterized by MIP observing that the size of the pores in the hydrated cement phases varies from the micro to the nanoscale. Uptake studies of HTO, 36Cl- and 129Ifrom batch sorption experiments indicate very weak sorption (Kd < 0.40 ± 0.13 L/kg) for the 3 selected radionuclides. The uptake process of 36Cl- and 129I- is probably associated with surface processes in the C-S-H and C-A-S-H phases with competition for sorption sites, between them. In the case of HTO, isotopic exchange with the interlayer water of the C-S-H and the C-A-S-H seems to be the main uptake process
The Leeway of Shipping Containers at Different Immersion Levels
The leeway of 20-foot containers in typical distress conditions is
established through field experiments in a Norwegian fjord and in open-ocean
conditions off the coast of France with wind speed ranging from calm to 14 m/s.
The experimental setup is described in detail and certain recommendations given
for experiments on objects of this size. The results are compared with the
leeway of a scaled-down container before the full set of measured leeway
characteristics are compared with a semi-analytical model of immersed
containers. Our results are broadly consistent with the semi-analytical model,
but the model is found to be sensitive to choice of drag coefficient and makes
no estimate of the cross-wind leeway of containers. We extend the results from
the semi-analytical immersion model by extrapolating the observed leeway
divergence and estimates of the experimental uncertainty to various realistic
immersion levels. The sensitivity of these leeway estimates at different
immersion levels are tested using a stochastic trajectory model. Search areas
are found to be sensitive to the exact immersion levels, the choice of drag
coefficient and somewhat less sensitive to the inclusion of leeway divergence.
We further compare the search areas thus found with a range of trajectories
estimated using the semi-analytical model with only perturbations to the
immersion level. We find that the search areas calculated without estimates of
crosswind leeway and its uncertainty will grossly underestimate the rate of
expansion of the search areas. We recommend that stochastic trajectory models
of container drift should account for these uncertainties by generating search
areas for different immersion levels and with the uncertainties in crosswind
and downwind leeway reported from our field experiments.Comment: 25 pages, 11 figures and 5 tables; Ocean Dynamics, Special Issue on
Advances in Search and Rescue at Sea (2012
Simulation of truncated normal variables
We provide in this paper simulation algorithms for one-sided and two-sided
truncated normal distributions. These algorithms are then used to simulate
multivariate normal variables with restricted parameter space for any
covariance structure.Comment: This 1992 paper appeared in 1995 in Statistics and Computing and the
gist of it is contained in Monte Carlo Statistical Methods (2004), but I
receive weekly requests for reprints so here it is
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