351 research outputs found

    Marginally trapped submanifolds in Lorentzian space forms and in the Lorentzian product of a space form by the real line

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    We give local, explicit representation formulas for n-dimensional spacelike submanifolds which are marginally trapped in the Minkowski space, the de Sitter and anti de Sitter spaces and the Lorentzian products of the sphere and the hyperbolic space by the real line.Comment: 20 pages. Third version: a few corrections have been done. The bibliography has been update

    Improvements in heat transfer network modelling for oil-cooled power transformer windings

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    Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.In this paper accurate modelling of heat transfer from power transformer winding conductors to cooling oil is envisaged. To this end the network model of Radakovic & Sorgic [1] is validated against more detailed CFD simulation results. Based on this comparison, three model improvements to the network model are proposed. They concern the governing heat transfer correlation, the introduction of thermal boundary layer tracking and an improved description for the thermal resistance in the solid. The improved network model results in more accurate results.The authors acknowledge support from the IWT, in the context of a Baekeland Mandate.am201

    Marginally Trapped Surfaces in the Nonsymmetric Gravitational Theory

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    We consider a simple, physical approach to the problem of marginally trapped surfaces in the Nonsymmetric Gravitational Theory (NGT). We apply this approach to a particular spherically symmetric, Wyman sector gravitational field, consisting of a pulse in the antisymmetric field variable. We demonstrate that marginally trapped surfaces do exist for this choice of initial data.Comment: REVTeX 3.0 with epsf macros and AMS symbols, 3 pages, 1 figur

    Kasterlee Binnenpad Parking Een archeologische opgraving

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    Dit rapport werd ingediend bij het agentschap samen met een aantal afzonderlijke digitale bijlagen. Een aantal van deze bijlagen zijn niet inbegrepen in dit pdf document en zijn niet online beschikbaar. Sommige bijlagen (grondplannen, fotos, spoorbeschrijvingen, enz.) kunnen van belang zijn voor een betere lezing en interpretatie van dit rapport. Indien u deze bijlagen wenst te raadplegen kan u daarvoor contact opnemen met: [email protected]

    Low grade mosaic for a complex supernumerary ring chromosome 18 in an adult patient with multiple congenital anomalies

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    Background. Several cases have been reported of patients with a ring chromosome 18 replacing one of the normal chromosomes 18. Less common are patients with a supernumerary ring chromosomes 18. High resolution whole genome examination in patients with multiple congenital abnormalities might reveal cytogenetic abnormalities of an unexpected complexity. Results. We report a 24 years old male patient with lower spinal anomalies, hypospadia, bifid scrotum, cryptorchism, anal atresia, kidney stones, urethra anomalies, radial dysplasia, and a hypoplastic thumb. Some of the anomalies overlap with the VACTERL association. Chromosome analysis of cultured peripheral blood lymphocytes revealed an additional ring chromosome in 13% of the metaphases. Both parents had a normal karyotype, demonstrating the de novo origin of this ring chromosome. FISH analysis using whole chromosome paints showed that the additional chromosomal material was derived from chromosome 18. Chromosome analysis of cultured fibroblasts revealed only one cell with the supernumerary ring chromosome in the 400 analyzed. To characterize the ring chromosome in more detail peripheral blood derived DNA was analyzed using SNP-arrays. The array results indicated a 5 Mb gain of the pericentromeric region of chromosome 18q10-q11.2. FISH analysis using BAC-probes located in the region indicated the presence of 6 signals on the r(18) chromosome. In addition, microsatellite analysis demonstrated that the unique supernumerary ring chromosome was paternally derived and both normal copies showed biparental disomy. Conclusions. We report on an adult patient with multiple congenital abnormalities who had in 13% of his cells a unique supernumerary ring chromosome 18 that was composed of 6 copies of the 5 Mb gene rich region of 18q11

    Adult-onset autoinflammation caused by somatic mutations in UBA1:A Dutch case series of patients with VEXAS

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    Background: A novel autoinflammatory syndrome was recently described in male patients who harbored somatic mutations in the X-chromosomal UBA1 gene. These patients were characterized by adult-onset, treatment-refractory inflammation with fever, cytopenia, dysplastic bone marrow, vacuoles in myeloid and erythroid progenitor cells, cutaneous and pulmonary inflammation, chondritis, and vasculitis, which is abbreviated as VEXAS. Objective: This study aimed to (retrospectively) diagnose VEXAS in patients who had previously been registered as having unclassified autoinflammation. We furthermore aimed to describe clinical experiences with this multifaceted, complex disease. Methods: A systematic reanalysis of whole-exome sequencing data from a cohort of undiagnosed patients with autoinflammation from academic hospitals in The Netherlands was performed. When no sequencing data were available, targeted Sanger sequencing was applied in cases with high clinical suspicion of VEXAS. Results: A total of 12 male patients who carried mutations in UBA1 were identified. These patients presented with adult-onset (mean age 67 years, range 47-79 years) autoinflammation with systemic symptoms, elevated inflammatory parameters, and multiorgan involvement, most typically involving the skin and bone marrow. Novel features of VEXAS included interstitial nephritis, cardiac involvement, stroke, and intestinal perforation related to treatment with tocilizumab. Although many types of treatment were initiated, most patients became treatment-refractory, with a high mortality rate of 50%. Conclusion: VEXAS should be considered in the differential diagnosis of males with adult-onset autoinflammation characterized by systemic symptoms and multiorgan involvement. Early diagnosis can prevent unnecessary diagnostic procedures and provide better prognostic information and more suitable treatment options, including stem cell transplantation

    Role of nitrogen lewis basicity in boronate affinity chromatography of nucleosides. Anal

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    Urinary modified nucleosides have a potential role as cancer biomarkers, and most of the methods used in their study have utilized low-pressure phenylboronate affinity chromatography materials for the purification of the cisdiol-containing nucleosides. In this study, a boronate HPLC column was surprisingly shown not to trap the nucleosides as would be expected from experience with the classic Affigel 601 resin but showed only partial selectivity toward cis-diol groups while other groups exhibited better retention. In aprotic conditions, trapping of nucleosides was possible; however, the selectivity toward cis-diol-containing compounds was lost with the Lewis basicity of available nitrogens being the main determinant of retention. The experimental findings are compared to and confirmed by DFT calculations. Modified nucleosides are naturally occurring modifications of the "normal" nucleosides. They have various roles within many nucleic acids but are mainly found in transfer RNA. They are excreted from the body via the urine as they cannot be salvaged; moreover, some are toxic when allowed to accumulate. Many past reports have investigated the modified nucleosides as potential cancer biomarkers and indicate considerable promise. [1][2][3][4][5] The methodologies used in these studies are wide ranging; however, since the introduction of boronate affinity chromatography as a ribonucleoside-selective cleanup step, on Affi-Gel 601 (Bio-Rad), utilized by Gehrke et al., 1,2 most research employed this off-line cleanup step process in the analysis. The subsequent identification/quantification of the ribonucleosides was almost exclusively carried out via RPLC-UV methods. More recently, some CE-UV methods have also been developed. [6][7][8][9] The further potential/ demand to obtain unambiguous identification via mass spectrometric detection led to the development of some off-line boronate chromatography GC/MS procedures. 3,5,10 However, the most natural choice for the analysis of the prepurified urinary nucleosides analysis is found in LC-MS. 11 Yet, the development of LC-MS procedures for urinary nucleosides only advanced 12 when electrospray mass spectrometry (ESI-MS) became available. Past studies by our group have considered the cleanup samples prior to ESI-MS analysis, 13 the optimization of the detection conditions, 14 comparison of various mass spectrometric methods, 15 and identification of the excreted nucleosides. 16,17 Other groups have taken advantage of mass spectrometry in the study of these compounds

    Randweg Baarle-Nassau (NL) - Baarle-Hertog (B) Een inventariserend Veldonderzoek in de vorm van proefsleuven

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    Dit rapport werd ingediend bij het agentschap samen met een aantal afzonderlijke digitale bijlagen. Een aantal van deze bijlagen zijn niet inbegrepen in dit pdf document en zijn niet online beschikbaar. Sommige bijlagen (grondplannen, fotos, spoorbeschrijvingen, enz.) kunnen van belang zijn voor een betere lezing en interpretatie van dit rapport. Indien u deze bijlagen wenst te raadplegen kan u daarvoor contact opnemen met: [email protected]
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