Determining source cumulants in femtoscopy with Gram-Charlier and Edgeworth series

Lowest-order cumulants provide important information on the shape of the emission source in femtoscopy. For the simple case of noninteracting identical particles, we show how the fourth-order source cumulant can be determined from measured cumulants in momentum space. The textbook Gram-Charlier series is found to be highly inaccurate, while the related Edgeworth series provides increasingly accurate estimates. Ordering of terms compatible with the Central Limit Theorem appears to play a crucial role even for nongaussian distributions.Comment: 11 pages, 2 figure

Model independent analysis of nearly L\'evy correlations

A model-independent method for the analysis of the two-particle short-range correlations is presented, that can be utilized to describe e.g. Bose-Einstein (HBT), dynamical (ridge) or other correlation functions, that have a nearly L\'evy or streched exponential shape. For the special case of L\'evy exponent alpha = 1, the earlier Laguerre expansions are recovered, for the alpha = 2 special case, a new expansion method is obtained for nearly Gaussian correlation functions. Multi-dimensional L\'evy expansions are also introduced and their potential application to analyze rigde correlation data is discussed

Rapid deconvolution of low-resolution time-of-flight data using Bayesian inference

The deconvolution of low-resolution time-of-flight data has numerous advantages, including the ability to extract additional information from the experimental data. We augment the well-known Lucy-Richardson deconvolution algorithm using various Bayesian prior distributions and show that a prior of second-differences of the signal outperforms the standard Lucy-Richardson algorithm, accelerating the rate of convergence by more than a factor of four, while preserving the peak amplitude ratios of a similar fraction of the total peaks. A novel stopping criterion and boosting mechanism are implemented to ensure that these methods converge to a similar final entropy and local minima are avoided. Improvement by a factor of two in mass resolution allows more accurate quantification of the spectra. The general method is demonstrated in this paper through the deconvolution of fragmentation peaks of the 2,5-dihydroxybenzoic acid matrix and the benzyltriphenylphosphonium thermometer ion, following femtosecond ultraviolet laser desorption

Screening for calreticulin mutations in a cohort of patients suspected of having a myeloproliferative neoplasm

Background. The discovery of calreticulin (CALR) has shown it to be the second most frequent mutation after the Janus Kinase 2 (JAK2) mutation in myeloproliferative neoplasms (MPNs). Its structure indicates various functions, of which two are to ensure calcium homeostasis and proper folding of other target proteins. Over 36 types of CALR mutations have been identified, all causing a recurrent frameshift in the C-terminal domain affecting CALR’s localisation and calcium-binding function.Objective. To screen a cohort of 89 patients suspected of having an MPN for the CALR mutations.Methods. Capillary and gel electrophoresis were used in conjunction as confirmatory tests to screen the cohort of patients. Results. Of three samples containing a type 1 CALR mutation, two were heterozygous and one homozygous for a 52-base pair deletion in CALR.Conclusions. Most studies report CALR mutations to be present only in patients with primary myelofibrosis or essential thrombocythaemia, with mutual exclusivity to JAK2 mutations. The findings of this study indicate that JAK2 and CALR mutations are no longer considered mutually exclusive. Similarly, patients with a polycythaemia vera phenotype could also carry a CALR mutation

Screening for calreticulin mutations in a cohort of patients suspected of having a myeloproliferative neoplasm

Background. The discovery of calreticulin (CALR) has shown it to be the second most frequent mutation after the Janus Kinase 2 (JAK2) mutation in myeloproliferative neoplasms (MPNs). Its structure indicates various functions, of which two are to ensure calcium homeostasis and proper folding of other target proteins. Over 36 types of CALR mutations have been identified, all causing a recurrent frameshift in the C-terminal domain affecting CALR’s localisation and calcium-binding function.Objective. To screen a cohort of 89 patients suspected of having an MPN for the CALR mutations.Methods. Capillary and gel electrophoresis were used in conjunction as confirmatory tests to screen the cohort of patients.Results. Of three samples containing a type 1 CALR mutation, two were heterozygous and one homozygous for a 52-base pair deletion in CALR.Conclusions. Most studies report CALR mutations to be present only in patients with primary myelofibrosis or essential thrombocythaemia, with mutual exclusivity to JAK2 mutations. The findings of this study indicate that JAK2 and CALR mutations are no longer considered mutually exclusive. Similarly, patients with a polycythaemia vera phenotype could also carry a CALR mutation

Incorporating structured text retrieval into the extended Boolean model

Conventional information retrieval models are inappropriate for use in databases containing semi-structured biographical data. A hybrid algorithm that effectively addresses many of the problems in searching biographical databases is presented in this article. An overview of applicable structured text retrieval algorithms is given, with focus specifically on the tree matching model. Small adaptations to the Extended Boolean Model, to make it more applicable to biographical databases, are described. The adaptation of tree matching models to the hierarchical nature of data in a person record is described and a distance function between query and record is defined. A hybrid model between the Extended Boolean Model and the adapted Tree Matching Model is then presented. A fast ranking algorithm appropriate for general searches and a more effective (but more resource intensive) algorithm for more advanced searches is given. It is shown how dates can be incorporated in the hybrid model to create a more powerful search algorithm. The hybrid algorithm can be used to rank records in descending order of relevance to a user's query

The determination of phosphorus in saliva and dentine

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