123 research outputs found
Experiments in fault tolerant software reliability
The reliability of voting was evaluated in a fault-tolerant software system for small output spaces. The effectiveness of the back-to-back testing process was investigated. Version 3.0 of the RSDIMU-ATS, a semi-automated test bed for certification testing of RSDIMU software, was prepared and distributed. Software reliability estimation methods based on non-random sampling are being studied. The investigation of existing fault-tolerance models was continued and formulation of new models was initiated
Treatment of Polarographic Data by the Method of Least-squares. II. Simultaneous Estimation of the Diffusion Current and the Half-wave Potential
By applying the method of least squares it is possible to estimate simultaneously the diffusion current and the half-wave potential with precision which exceeds that of the usual graphical methods. The method described in this paper is particularly suitable for analysing composite current-voltage curves. An example is given of the analysis of the composite curve obtained with a solution containing thallous and lead ions in 0.1 N KC
Determination of lead in blood
Opisana je »jednobojna« metoda za određivanje malih količina olova u krvi s pomoću ditizona. Glavne razlike između predložene metode i uobičajenih postupaka su ove: 1. Ekstrakcija olova vrši se kod razmjerno visoke pH vrijednosti (10,5), 2. željezo se uklanja nakon mineralizacije krvi, a prije ekstrakcije ditizona. Za odstranjivanje željeza upotrebljen je kupferon. Baždarne krivulje obrađene su statistički. Rezultati pokazuju, da je tako modificirana ditizonska metoda pouzdana, osjetljiva i precizna. Standardna pogreška pojedinog određivanja nije veća od ± 7 µg za koncentracije olova od 25 do 500 µg/100 ml krvi, ako se mjerenje ekstinkcije vrši Beckmanovim spektralnirn fotometrom kod valne dužine od 520 mµ. Ako paralelno analiziramo po dva uzorka iste krvi, standardna se pogreška može smanjili na ± 5 µg.A »mono-colour« dithizone method for determination of lead in blood is described. The main points in which the proposed method differs from the usual dithizone methods are the following:
(1) the extraction of lead with dithizone solution is performed at rather high pH values (10.5),
(2) the iron is removed after mincra lization of blood by means of a 2% aqueous cupferron solution.
The modification (I) increases the sensitivity of the method and at the same time dispenses with the necessity of washing lead-dithizonate solution to remove the excess dithizone before measuring the extinction. The cupferron extraction eliminates all the possible sources of error which are connected with the presence of iron. The statistical treatment of calibration curves showed that the proposed method is reliable, sensitive and precise. The standard error of a single determination is not more than ±7 µg for lead concentrations from 25 to 500 µg per 100 ml blood if the measurement of the optical density is performed with Beckman spectrophotometer at 520 mµ. If two parallel determinations arc made in each analysis the standard error may be reduced to ±5 µg
An experimental evaluation of software redundancy as a strategy for improving reliability
The strategy of using multiple versions of independently developed software as a means to tolerate residual software design faults is suggested by the success of hardware redundancy for tolerating hardware failures. Although, as generally accepted, the independence of hardware failures resulting from physical wearout can lead to substantial increases in reliability for redundant hardware structures, a similar conclusion is not immediate for software. The degree to which design faults are manifested as independent failures determines the effectiveness of redundancy as a method for improving software reliability. Interest in multi-version software centers on whether it provides an adequate measure of increased reliability to warrant its use in critical applications. The effectiveness of multi-version software is studied by comparing estimates of the failure probabilities of these systems with the failure probabilities of single versions. The estimates are obtained under a model of dependent failures and compared with estimates obtained when failures are assumed to be independent. The experimental results are based on twenty versions of an aerospace application developed and certified by sixty programmers from four universities. Descriptions of the application, development and certification processes, and operational evaluation are given together with an analysis of the twenty versions
Toward a first-principles integrated simulation of tokamak edge plasmas
Performance of the ITER is anticipated to be highly sensitive to the edge plasma condition. The edge pedestal in ITER needs to be predicted from an integrated simulation of the necessary first-principles, multi-scale physics codes. The mission of the SciDAC Fusion Simulation Project (FSP) Prototype Center for Plasma Edge Simulation (CPES) is to deliver such a code integration framework by (1) building new kinetic codes XGC0 and XGC1, which can simulate the edge pedestal buildup; (2) using and improving the existing MHD codes ELITE, M3D-OMP, M3D-MPP and NIMROD, for study of large-scale edge instabilities called Edge Localized Modes (ELMs); and (3) integrating the codes into a framework using cutting-edge computer science technology. Collaborative effort among physics, computer science, and applied mathematics within CPES has created the first working version of the End-to-end Framework for Fusion Integrated Simulation (EFFIS), which can be used to study the pedestal-ELM cycles
PKD1 and PKD2 mutations in Slovenian families with autosomal dominant polycystic kidney disease
BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a genetically heterogeneous disorder caused by mutations in at least two different loci. Prior to performing mutation screening, if DNA samples of sufficient number of family members are available, it is worthwhile to assign the gene involved in disease progression by the genetic linkage analysis. METHODS: We collected samples from 36 Slovene ADPKD families and performed linkage analysis in 16 of them. Linkage was assessed by the use of microsatellite polymorphic markers, four in the case of PKD1 (KG8, AC2.5, CW3 and CW2) and five for PKD2 (D4S1534, D4S2929, D4S1542, D4S1563 and D4S423). Partial PKD1 mutation screening was undertaken by analysing exons 23 and 31–46 and PKD2 . RESULTS: Lod scores indicated linkage to PKD1 in six families and to PKD2 in two families. One family was linked to none and in seven families linkage to both genes was possible. Partial PKD1 mutation screening was performed in 33 patients (including 20 patients from the families where linkage analysis could not be performed). We analysed PKD2 in 2 patients where lod scores indicated linkage to PKD2 and in 7 families where linkage to both genes was possible. We detected six mutations and eight polymorphisms in PKD1 and one mutation and three polymorphisms in PKD2. CONCLUSION: In our study group of ADPKD patients we detected seven mutations: three frameshift, one missense, two nonsense and one putative splicing mutation. Three have been described previously and 4 are novel. Three newly described framesfift mutations in PKD1 seem to be associated with more severe clinical course of ADPKD. Previously described nonsense mutation in PKD2 seems to be associated with cysts in liver and milder clinical course
Armadillo 1.1: An Original Workflow Platform for Designing and Conducting Phylogenetic Analysis and Simulations
In this paper we introduce Armadillo v1.1, a novel workflow platform dedicated to designing and conducting phylogenetic studies, including comprehensive simulations. A number of important phylogenetic and general bioinformatics tools have been included in the first software release. As Armadillo is an open-source project, it allows scientists to develop their own modules as well as to integrate existing computer applications. Using our workflow platform, different complex phylogenetic tasks can be modeled and presented in a single workflow without any prior knowledge of programming techniques. The first version of Armadillo was successfully used by professors of bioinformatics at Université du Quebec à Montreal during graduate computational biology courses taught in 2010–11. The program and its source code are freely available at: <http://www.bioinfo.uqam.ca/armadillo>
Comparison of circulating lipid profiles between fasting humans and three animal species used in preclinical studies: mice, rats and rabbits
Cost estimate of immune-related adverse reactions associated with innovative treatments of metastatic melanoma
Background and Objective Immuno-oncology therapies represent a new treatment opportunity for patients affected by metastatic melanoma. The purpose of this study was to estimate the costs of immune-related adverse events (irAEs) associated with the new anti-PD1 immuno-oncology therapies, with the anti-CTLA-4 immuno-oncology therapy and with the combined therapy (CTLA4 + anti-PD1) in patients affected by metastatic melanoma.Materials and Methods A probabilistic cost-of-illness (COI) model was developed to estimate the management costs of grade >= 3 adverse events associated with the new anti-PD1 therapies (pembrolizumab and nivolumab), the anti-CTLA-4 therapy (ipilimumab) and the combined therapy CTLA4 + anti-PD1 (nivolumab + ipilimumab) for the treatment of patients with metastatic melanoma from the National Health Service (NHS) perspective in Italy. Identification of the epidemiological and cost parameters was carried out through a systematic literature review (SLR). Univariate and probabilistic sensitivity analyses were performed to account for uncertainty and variation in the model results.Results The model estimated a cost associated with the management of grade >= 3 immune-related adverse events in patients with metastatic melanoma equal to (sic)176.2 (95% CI 63.5-335.0) for anti-CTLA-4 therapy, (sic)48.6 (95% CI 40.1-58.5) for the new anti-PDI therapies and (sic)276.8 (95% CI 240.4-316.2) for the combined therapy. Among the innovative therapies for the considered metastatic melanoma, the combined therapy was the most expensive innovative treatment in terms of event management of immune-related grade >= 3 adverse events.Conclusion This study may represent a useful tool to understand the economic burden associated with the management of irAEs associated with patients affected by metastatic melanoma
Higher plasma levels of lysophosphatidylcholine 18:0 are related to a lower risk of common cancers in a prospective metabolomics study
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