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Highly accurate and reproducible genotype calling is a key to success of genome-wide association studies (GWAS) since errors introduced by calling algorithms can lead to inflation of false associations between genotype and phenotype. The Affymetrix Genome-Wide Human SNP Array 6.0 is widely utilized and was used in the current GWAS. Birdseed, a genotype-calling algorithm for this chip, is available in two versions. It is important to know the reproducibility between the two versions. We assessed the inconsistency in genotypes called by the two versions of Birdseed and examined the propagation of the genotype inconsistency to the downstream association analysis by using the 270 HapMap samples. Our results revealed that genotypes called from version-1 and version-2 of Birdseed were slightly different and the inconsistency in genotypes propagated to the downstream association analysis. [ABSTRACT FROM AUTHOR]

We report on design details and first results obtained with the transportable absolute gravimeter MPG-2 (˵Max-Planck-Gravimeter″). It is developed as an evolution of the stationary device MPG-1, completed in 2007. The MPG-2 is built on a common scheme where the position of a freely falling object is monitored. The setup consists of a ballistic block, an interferometer and the electronics. Free fall drops can be repeated every 10 s with the standard deviation close to 30 μgal. A one-day gravity observation gives a result with a standard deviation of the mean of less than 5 μgal. A prototype of the MPG-2 took part in the ECAG-2007. New measurements at the reference gravity station ˵Bad Homburg″, Germany confirmed the declared combined standard uncertainty of 50 μgal. [ABSTRACT FROM AUTHOR]

We introduce the role of resampling and prediction (p) metrics for flexible discriminant modeling in neuroimaging, and highlight the importance of combining these with measurements of the reproducibility (r) of extracted brain activation patterns. Using the NPAIRS resampling framework we illustrate the use of (p, r) plots as a function of the size of the principal component subspace (Q) for a penalized discriminant analysis (PDA) to: optimize processing pipelines in functional magnetic resonance imaging (fMRI), and measure the global SNR (gSNR) and dimensionality of fMRI data sets. We show that the gSNRs of typical fMRI data sets cause the optimal Q for a PDA to often lie in a phase transition region between gSNR ≃ 1 with large optimal Q versus SNR » 1 with small optimal Q. [ABSTRACT FROM AUTHOR]

Biometric Hash algorithms, also called BioHash, are mainly designed to ensure template protection to its biometric raw data. To assure reproducibility, BioHash algorithms provide a certain level of robustness against input variability to ensure high reproduction rates by compensating for intra-class variation of the biometric raw data. This concept can be a potential vulnerability. In this paper, we want to reflect such vulnerability of a specific Biometric Hash algorithm for handwriting, which was introduced in [1], consider and discuss possible attempts to exploit these flaws. We introduce a new reconstruction approach, which exploits this vulnerability; to generate artificial raw data out of a reference BioHash. Motivated by work from Cappelli et al. for fingerprint modality in [6] further studied in [3], where such an artificially generated raw data has the property of producing false positive recognitions, although they may not necessarily be visually similar. Our new approach for handwriting is based on genetic algorithms combined with user interaction in using a design vulnerability of the BioHash with an attack corresponding to cipher-text-only attack with side information as system parameters from BioHash. To show the general validity of our concept, in first experiments we evaluate using 60 raw data sets (5 individuals overall) consisting of two different handwritten semantics (arbitrary Symbol and fixed PIN). Experimental results demonstrate that reconstructed raw data produces an EERreconstr. in the range from 30% to 75%, as compared to non-attacked inter-class EERinter-class of 5% to 10% and handwritten PIN semantic can be better reconstructed than the Symbol semantic using this new technique. The security flaws of the Biometric Hash algorithm are pointed out and possible countermeasures are proposed. [ABSTRACT FROM AUTHOR]

Computer-aided detection (CAD) systems are improving their performance both in terms of sensitivity and specificity, but false prompts remain an area of interest because of their potential to distract from prompts marking real abnormalities and to reduce the importance attached to any given prompt by a film reader. Many false prompts are very near to the threshold for prompting: in this study we investigate reproducibility of prompting by a commercial CAD system. [ABSTRACT FROM AUTHOR]

The determination of hashes based on biometric data is a recent topic in biometrics as it allows to handle biometric templates in a privacy manner. Two main applications are the generation of secure biometric templates and cryptographic keys. Depending on these applications, there are different requirements with regard to possible errors. On one side, authentication performance based on biometric hashes as feature representation can be measured by common biometric error rates such as EER. Thus, generated hashes for each single person have to be only similar in a certain degree. On the other side, biometric hashes for cryptographic issues have to be identical and unique for each individual, although measured data from same person differs or data from different people may be similar. Therefore, we suggest three measures to estimate the reproducibility performance of biometric hash algorithms for cryptographic applications. To prove the concept of the measures, we provide an experimental evaluation of an online handwriting based hash generation algorithm using a database of 84 users and different evaluation scenarios. [ABSTRACT FROM AUTHOR]

Purpose: Breathing induced target motion may influence the accuracy of radiotherapy treatment – especially for stereotactic body radiotherapy. The work will focus on reproducibility of tumour motion which was acquired before and during radiation therapy. Methods: Two imaging techniques were used to determined tumour motion of 27 target volumes of 24 patients via 4D computer tomography (4DCT) and portal image system (EPID). EPID movies were analyzed by means of motion amplitude. Motion amplitude was calculated by the difference of tumour position in maximum inspiration and maximum expiration. Results: The evaluation of the EPID movies showed that 48 % and 22 % of investigated target volumes were moving more than 5 mm and 10 mm, respectively. A strong correlation was seen between motion determined in 4DCT and EPID movies (CC 0.87). Conclusion: Tumour motion acquired in 4DCT and portal image movies showed good correlation. For some target volumes large deviations of motion amplitudes were observed. [ABSTRACT FROM AUTHOR]