Cerebral microbleeds and cognitive decline in a hemodialysis patient: Case report and review of literature

Cerebral microbleeds (CMBs) are small hemosiderin deposits indicative of prior cerebral microscopic hemorrhage and previously thought to be clinically silent. Recent population‐based cross‐sectional studies and prospective longitudinal cohort studies have revealed association between CMB and cognitive dysfunction. In the general population, CMBs are associated with age, hypertension, and cerebral amyloid angiopathy. In the chronic kidney disease (CKD) population, diminished estimated glomerular filtration rate has been found to be an independent risk factor for CMB, raising the possibility that a uremic milieu may predispose to microbleeds. In the end‐stage renal disease (ESRD) population on hemodialysis, the incidence of microbleeds is significantly higher compared with a control group without history of CKD or stroke. We present an ESRD patient on chronic hemodialysis with a history of gradual cognitive decline and progressive CMBs. Through this case and literature review, we illustrate the need to develop detection and prediction models to treat this frequent development in ESRD patients.     

Tay-Sachs disease in persons of French-Canadian heritage in northern New England

This study sought to determine whether persons of French-Canadian heritage in northern New England are at high risk for the lethal infantile form of Tay-Sachs disease. In order to accomplish this, death records and laboratory diagnostic records were surveyed to ascertain Tay-Sachs deaths in a cohort of 372,000 live births between 1977-1986. The proportion of the total population with French-Canadian or Jewish heritage was determined from census and birth records, and the ethnic background of Tay-Sachs cases was determined from the corresponding birth records. In 1,860 births, both parents were of Ashkenazi Jewish heritage. One of those children was diagnosed with Tay-Sachs disease. In 41,000 births, both parents were of French-Canadian heritage, and in an additional 93,000 births, one parent was of French-Canadian heritage. No cases of Tay-Sachs disease were identified in the offspring of those individuals. Approximately 14 cases (95% confidence interval 8-20) would be expected, if the gene frequency approximated that reported for individuals of Ashkenazi Jewish heritage. Based on the results of this study, routine testing for Tay-Sachs disease heterozygosity is not indicated for persons of French-Canadian heritage in northern New England. This conclusion may not necessarily be valid for persons of French-Canadian heritage residing in other states. Further studies of Tay-Sachs disease mutations and prevalence among persons of French-Canadian heritage will be important to determine possible regional variations in gene frequencies.     

A comparative study of transient waves in random (polycrystalline) media

The paper investigates the transient response of a random medium as predicted by two methods, a perturbation scheme and a causal approach. It is shown by direct computation of a pulse propagation that the perturbation scheme yields an advanced response inconsistent with the physical realizability of the medium. The causal model as well as a modified perturbation scheme exhibit a physically reasonable behavior.     

Inactivation of Staphylococcus hyicus lipase by hexadecylsulfonyl fluoride: evidence for an active site serine

The Staphylococcus hyicus lipase is an acyl hydrolase with broadsubstrate specificity including neutral glycerides and phospholipids.To obtain further insight into the mechanism of action of thisenzyme, we tested several sulfonyl fluorides as active site-directedinhibitors. The enzyme is resistant to the well-known serineprotease/esterase inhibitor phenylmethanesulfonyl fluoride (PMSF),but is rapidly inactivated by hexadecylsulfonyl fluoride. Thekinetics of inactivation were studied in Triton X-100 micelles.Inactivation is fast and the rate of inactivation is constantover the pH range where this lipase is active. Metal ions likeCa²⁺ and Sr²⁺ do not appreciably influence the rate of inactivation,although the enzymatic activity is significantly increased,suggesting a structural role for these ions. The S.hyicus lipasecontains a consensus sequence G-H/Y-S-X-G. Substitution by site-directedmutagenesis of this serine (Ser369) by a cysteine resulted ina mutant with only 0.2% residual activity. The activity of thismutant could not be inhibited with water-soluble sulfhydrylreagents either in the presence or absence of Triton X-100 micelles.In the presence of Triton X-100 micelles, inactivation of themutant occurred with 4-nitrophenylhexadecyl disulfide (t_1/2= 125 min) while the wild-type enzyme does not react at all.We conclude that Ser369 is the active site residue and thatin water this residue is inaccessible. Only after interfacialactivation Ser369 (or Cys369) becomes exposed and reacts withirreversible inhibitors.     

Monte Carlo techniques for phrase-based translation

Recent advances in statistical machine translation have used approximate beam search for NP-complete inference within probabilistic translation models. We present an alternative approach of sampling from the posterior distribution defined by a translation model. We define a novel Gibbs sampler for sampling translations given a source sentence and show that it effectively explores this posterior distribution. In doing so we overcome the limitations of heuristic beam search and obtain theoretically sound solutions to inference problems such as finding the maximum probability translation and minimum risk training and decoding.     

Development and Performance of Crystallization with Additives Applied on Different Milk Samples

Crystallization with additives is developed on milk samples from different processing treatments. Performance tests are carried out based on structure analysis of the crystallization patterns. Crystallization with milk as additive is applied following changes in milk after different processing treatments. When an aqueous cupric chloride dihydrate solution crystallizes in the presence of milk as additive, specific patterns emerge, which can be evaluated by image analysis. Milk samples were heated and homogenized in a pilot plant and characterized by various parameters. Furthermore, milk samples from the market were tested. Patterns from milk after heat treatment and homogenization are significantly different from those derived from untreated milk. The experiments could be reproduced for other milk samples, on different days and in another laboratory.     

The route to a defect tolerant LUT through artificial evolution

Evolutionary techniques may be applied to search for specific structures or functions, as specified in the fitness function. This paper addresses the challenge of finding an appropriate fitness function when searching for generic rather than specific structures which, when combined wiacteristic of defect tolerance on the circuit. Production defects for integrated circuits are expected to increase considerably. To avoid a corresponding drop in yield, improved defect tolerance solutions are needed. In the case of Field Programmable Gate Arrays (FPGAs), the pre-designed gate array provides a bridge between production and the application designers. Thus, introduction of defect tolerant techniques to the FPGA itself could provide a defect free gate array to the application designer, despite production defects. The search for defect tolerance presented herein is directed at finding defect tolerant structures for an important building block of FPGAs: Look-Up Tables (LUTs). Two key approaches are presented: (1) applying evolved generic building blocks to a traditional LUT design and (2) evolving the LUT design directly. The results highlight the fact that evolved generic defect tolerant structures can contribute to highly reliable circuit designs at the expense of area usage. Further, they show that applying such a technique, rather than direct evolution, has benefits with respect to evolvability of larger circuits, again at the expense of area usage.     

Security requirement analysis of business processes

Economic globalization leads to complex decentralized company structures calling for the extensive use of distributed IT-systems. The business processes of a company have to reflect these changes of infrastructure. In particular, due to new electronic applications and the inclusion of a higher number of—potentially unknown—persons, the business processes are more vulnerable against malicious attacks than traditional processes. Thus, a business should undergo a security analysis. Here, the vulnerabilities of the business process are recognized, the risks resulting from the vulnerabilities are calculated, and suitable safeguards reducing the vulnerabilities are selected. Unfortunately, a security analysis tends to be complex and affords expensive security expert support. In order to reduce the expense and to enable domain experts with in-depth insight in business processes but with limited knowledge about security to develop secure business processes, we developed the framework MoSS_BP facilitating the handling of business process security requirements from their specification to their realization. In particular, MoSS _BP provides graphical concepts to specify security requirements, repositories of various mechanisms enforcing the security requirements, and a collection of reference models and case studies enabling the modification of the business processes. In this paper, the MoSS _BP -framework is presented. Additionally, we introduce a tool supporting the MoSS_BP-related security analysis of business processes and the incorporation of safeguards. This tool is based on object-oriented process models and acts with graph rewrite systems. Finally, we clarify the application of the MoSS_BP-framework by means of a business process for tender-handling which is provided by anonymity-preserving safeguards. Peter Herrmann studied computer science at the University of Karlsruhe, Germany (diploma in 1990). Afterwards, he worked as a Ph.D. student (doctorate in 1997) and postdoctoral researcher in the Computer Networks and Distributed Systems Group of the Computer Science Department at the University of Dortmund, Germany. Since 2005 he is a full professor for formal methods at the Department for Telematics of the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway. His research interests include the formal-based development of networked systems and the engineering of distributed services. Moreover, he is interested in security and trust aspects of component structured distributed software. Gaby Herrmann studied computer science at the University of Karlsruhe, Germany (diploma in 1991). Afterwards, she worked as a researcher in the Communication Group and the Information Systems Group at University of Duisburg-Essen (Doctorate in 2001, topic: security of business processes). Since 2000 she works as executive secretary at the Department of Economics, Business Studies and Computer Sciences at the same university.     

Elastic waves generated by loading applied to surface of spherical cavity

The elastodynamic problem of an unbounded body, subjected to a rotationally symmetric application of tractions at the surface of a spherical cavity, is studied. In general this problem involves three independent variables, which are the radius, colatitude and time, but it is shown how the method of characteristics for one spatial variable and time can be applied when the dependent variables are expanded as series of Legendre Polynomials. The procedure is in contrast to ones employed previously in that it does not involve integral transforms or asymptotic approximations and the field variables can be obtained for small and large times.     

Citation analysis and peer ranking of Australian social science journals

Citation analyses were performed for Australian social science journals to determine the differences between data drawn from Web of Science and Scopus. These data were compared with the tier rankings assigned by disciplinary groups to the journals for the purposes of a new research assessment model, Excellence in Research for Australia (ERA), due to be implemented in 2010. In addition, citation-based indicators including an extended journal impact factor, the h-index, and a modified journal diffusion factor, were calculated to assess whether subsequent analyses influence the ranking of journals. The findings suggest that the Scopus database provides higher number of citations for more of the journals. However, there appears to be very little association between the assigned tier ranking of journals and their rank derived from citations data. The implications for Australian social science researchers are discussed in relation to the use of citation analysis in the ERA.