Unifying statistical classification and geodesic active regions for segmentation of cardiac MRI

This paper presents a segmentation method that extends geodesic active region methods by the incorporation of a statistical classifier trained using feature selection. The classifier provides class probability maps based on class representative local features, and the geodesic active region formulation enables the partitioning of the image according to the region information. We demonstrate automatic segmentation results of the myocardium in cardiac late gadolinium-enhanced magnetic resonance imaging (CE-MRI) data using coupled level set curve evolutions, in which the classifier is incorporated both from a region term and from a shape term from particle filtering. The results show potential for clinical studies of scar tissue in late CE-MRI data.     

Weldability Aspects of a Newly Developed Duplex Stainless Steel LDX 2101

Duplex grades have, due to balanced chemical compositions of both filler and base metals, a weldability that allows for successful welding using a majority of the technically relevant techniques of today. In order to fulfil the performance requirements several aspects must be considered. In the heat affected zone (HAZ) the austenite reformation must be reasonably high and in the weld metal the microstructure must be stable so that e.g. high productivity welding and multi‐pass welding are possible, without precipitation of detrimental phases in previous passes. This paper addresses the effect of alloying elements and thermal cycles on phase balance in the high temperature HAZ (HTHAZ) of the newly developed lean duplex grade LDX 2101 (EN 1.4162, UNS S32101). Bead‐on‐plate welds and simulated weld structures have been produced and investigated using metallography, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results are analysed using the thermodynamic database Thermo‐Calc and a model for phase transformation based on a paraequilibrium assumption for ferrite‐austenite transformation. In the temperature region outside the paraequilibrium domain, growth controlled by diffusion of substitutional elements was considered. The analysis follows a model by Cahn regarding grain boundary nucleated growth and the Hillert‐Engberg model on kinetics of spherical and planar growth.     

Between Elderly Parents and Grandchildren—Geographic Proximity and Trends in Four-Generation Families

In an ageing society, families may have an important role in the caretaking and well-being of the elderly. Demographic changes have an impact on the size and structure of families; one aspect is how intergenerational support is distributed when there is a need for support to both older and younger generations at the same time. Another vital aspect of the provision of care for the elderly is geographic proximity. This study is oriented towards the potential “both-end carers” i.e. persons who have grandchildren in potential need of care while still having living ageing parents. The incidence of having grandchildren and having living parents at age 55 and the proximity between generations is described using Swedish register data. The results show that the share of 55-year-olds who are grandparents decreased dramatically from 70% to 35% between 1990 and 2005. As expected, more 55-year-olds have living parents—a proportion that increased from 37% to 47% during this period. As a result of delayed childbearing among the children of these cohorts, the likelihood of belonging to a four-generation family among 55-year-olds has not increased, despite increased longevity. Furthermore, most individuals live within daily reach of their kin and no evidence was found of a trend of increasing geographic distances between generations.     

Prof. Dr.-Ing. Dr. h. c. Franz Kollmann Zum 65. Geburtstag

Ohne Zusammenfassung     

Strengthening a curated web of trust in a geographically distributed project

In this article the authors present a trust management scheme, derived from the horizontal and almost anarchic web of trust model, but following a curatorship step that allows it to become a centerpiece for authentication in Debian, one of the largest and longest lived free software projects and producer of the eponymous GNU/Linux software distribution. This is done by analyzing the experience gained through a large-scale key migration process that spanned five years and nearly 100% of the originally existing keys, carried out attempting to minimize loss of keyring connectivity and strength, while keeping up to date with the best current security practices.     

Acyl exchange between oleoyl-CoA and phosphatidylcholine in microsomes of developing soya bean cotyledons and its role in fatty acid desaturation

Microsomes of developing soya bean cotyledons transfer oleate from oleoyl-CoA to phosphatidylcholine (PC) by two different mechanisms: one in which oleate transfer is accompanied by the release of free CoA and another which results in the exchange of oleate from oleoyl-CoA for unsaturated 18-carbon fatty acids of PC. The acyl exchange can be demonstrated only when bovine serum albumin is present in the incubation medium. ATP-dependent acyl-CoA synthetase is not involved in the exchange process, which apparently does not require any cofactors. In light of this exchange process, the oleate desaturase system was reinvestigated in order to determine what the actual substrate for this system is. Upon incubation of microsomes with high concentrations of [¹⁴C] oleoyl-CoA, bovine serum albumin and NADH, it could be conclusively demonstrated that most oleic acid is desaturated while part of the PC molecule. The amounts of [¹⁴C] linoleoyl-CoA formed could be explained entirely by the acyl exchange. The physiological significance of the acyl exchange system is discussed. A new method for separation of acyl-CoA from other lipids and free CoA using reversed phase column chromatography also is described.     

Isocyanates,aminoisocyanates and amines from fires—a screening of common materials found in buildings

Isocyanates, aminoisocyanates and amines were quantified from the combustion of 24 different materials or products typically found in buildings. Small‐scale combustion experiments were conducted in the cone calorimeter, where generally well‐ventilated combustion conditions are attained. Measurements were further made in two different full‐scale experiments. Isocyanates and amino‐compounds were sampled using an impinger‐filter sampling system with a reagent solution of di‐n‐butylamine in toluene. Filter and impinger solution were analysed separately using LC‐MS technique. Further the particulate distribution in the smoke gases was determined by impactor technique, and selected gaseous compounds quantified by FTIR. It was found in the small‐scale that isocyanates were produced from the majority of the materials tested. The highest concentration was found for glass wool insulation, and further high concentrations were found for PUR products, particleboard, nitrile rubber and melamine. Lower concentrations were found for wood and cable‐products. Amino‐isocyanates and amines were generally found from PUR products only. The distribution of isocyanates between the particulate‐ and fluid phases varied for the different materials and a tendency to enrichment of particles was seen for some of the materials. Further, when comparing the potential health hazard between isocyanates and other major fire gases (based on NIOSH IDLH‐values) it was found that isocyanates in several cases represented the greatest hazard. Copyright © 2003 John Wiley & Sons, Ltd.     

Transformation approach to numerically integrating PDEs by means of WDF principles

As has been shown, attractive methods for numerically integrating partial differential equations (PDEs) resulting from physical problems can be obtained by simulating the actual physical passive (conservation of energy) dynamical system by means of a discrete passive dynamical system, and this in such a way that the full parallelism and the exclusively local nature of the interconnections (principle of action at proximity) are preserved. An alternative approach for developing such methods is presented which, while still using principles of the same type as those on which multidimensional wave digital filters (WDFs) are based, involves appropriate transformations of the original coordinates of the physical problem at hand. This alternative approach is not only easier to apply than the one referred to above but also more general; it is illustrated on the one hand by the same examples as those that have been used for the other approach, and on the other by showing the applicability to Maxwell's equations.