Usability of a home-based test for the measurement of fecal calprotectin in asymptomatic IBD patients.

The aim of our work was to test the usability of fecal calprotectin (FC) home-based test in inflammatory bowel disease (IBD) patients. METHODS: IBD patients were prospectively recruited. They had to measure FC with a dedicated tool and smartphone application, 5 times at two weeks intervals over an 8 weeks period. They had to fill in a usability questionnaire at the first and the last FC measurement. A System Usability Scale (SUS: 0-100) and the Global Score of Usability (GSU: 0-85) were calculated. FC was also centrally measured by ELISA. RESULTS: Fifty-eight patients were recruited. Forty-two performed at least one FC measurement and 27 performed all the FC requested measurements. The median (IQR) SUS (0-100) at the first and last use were 85 (78-90) and 81 (70-88), respectively; the median (IQR) GSU (0-85) at the first and last use were 74 (69-80) and 77 (68-83), respectively. Adherence to the planned measurements and usability of the tool were higher in females and in less severe disease. The intra-class correlation coefficient between home-based and centrally measured FC was 0.88. CONCLUSION: The adherence to home-based measurement of FC was fair. Usability scores for the home-based test were high. There was a good correlation with the centrally measured FC by ELISA

An LR framework incorporating sensitivity analysis to model multiple direct and secondary transfer events on skin surface

Bayesian logistic regression is used to model the probability of DNA recovery following direct and secondary transfer and persistence over a 24 h period between deposition and sample collection. Sub-source level likelihood ratios provided the raw data for activity-level analysis. Probabilities of secondary transfer are typically low, and there are challenges with small data-sets with low numbers of positive observations. However, the persistence of DNA over time can be modelled by a single logistic regression for both direct and secondary transfer, except that the time since deposition must be compensated by an offset value for the latter. This simplifies the analysis. Probabilities are used to inform an activity-level Bayesian Network that takes account of alternative propositions e.g. time of assault and time of social activities. The model is extended in order to take account of multiple contacts between person of interest and ’victim’. Variables taken into account include probabilities of direct and secondary transfer, along with background DNA from unknown individuals. The logistic regression analysis is Bayesian — for each analysis, 4000 separate simulations were carried out. Quantile assignments enable calculation of a plausible range of probabilities and sensitivity analysis is used to describe the corresponding variation of s that occur when modelled by the Bayesian network. It is noted that there is need for consistent experimental design, and analysis, to facilitate inter-laboratory comparisons. Appropriate recommendations are made. The open-source program written in R-code ALTRaP (Activity Level, Transfer, Recovery and Persistence) enables analysis of complex multiple transfer propositions that are commonplace in cases-work e.g. between those who cohabit. A number of case examples are provided. ALTRaP can be used to replicate the results and can easily be modified to incorporate different sets of data and variables

Quantitative Fluorescent PCR (QF-PCR) on microsatellites, a fast and quantitative method to assay chimeric DNA samples in honeybees (Apis mellifera)

The production of chimeras by nuclear transfer or cell transplantation requires functional tools for the detection of individuals that have successfully incorporated donor material. Quantitative Fluorescent PCR (QF-PCR) on microsatellites was employed on artificial chimeric honeybee DNA samples, to develop protocols for detection and quantification of donor genotypes after nuclear transfer and cell transplantations into honeybee embryos. Standard curves were produced for three microsatellite markers and demonstrate that there is a close to linear correlation between the amounts of donor genotypes estimated with QF-PCR and actual amounst of genotypes. The method was sensitive down to a 1% level and could detect and quantify small amounts of donor DNA in artificially mixed samples. QF-PCR offers fast and sensitive detection and quantification of genotypes and, thus, provides a useful tool for studies of chimeric honeybees and other species

Determination of shedder status: A comparison of two methods involving cell counting in fingerprints and the DNA analysis of handheld tubes

The shedder status of an individual may be important to consider in the context of DNA transfer, persistence and recovery and in Bayesian networks where a person’s shedder status may have an impact on the outcome. In this study we compared two methods to determine shedder status: the handheld tube (HH) method and a fluorescent cell count (CC) method. A poor association was observed between the numbers of detected cells in a fingerprint using the CC method and the strength of the DNA result with the HH method. The 20 participants were classified into low (25%), medium (50%) and high (25%) shedders based on the HH method. While the low and high shedders showed a good consistency between the replicates, the medium shedders varied more and have to be considered more carefully as they may act as either a high or a low shedder in an event of DNA transfer

Mapping of a Milk Production Quantitative Trait Locus to a 420-kb Region on Bovine Chromosome 6

A QTL affecting milk production traits was previously mapped to an interval of 7.5 cM on chromosome 6 in Norwegian dairy cattle. This article aimed to refine this position by increasing the map density in the region by a set of single-nucleotide polymorphisms and analyzing the data with a combined linkage and linkage disequilibrium approach. Through a series of single- and multitrait and single- and multipoint analyses, the QTL was positioned to an interval surrounded by the genes ABCG2 and LAP3. As no recombinations were detected in this interval, physical mapping was required for further refining. By using radiation hybrid mapping as well as BAC clones, the bovine and human comparative maps in the region are resolved, and the QTL is mapped within a distance of 420 kb