scholarly journals A Nonparametric Bayesian Approach to the Rare Type Match Problem

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 439
Author(s):  
Giulia Cereda ◽  
Richard D. Gill
Keyword(s):  
Likelihood Ratio ◽  
Empirical Bayes ◽  
Dirichlet Distribution ◽  
Match Problem ◽  
Rare Type ◽  
Dna Profile ◽  
Profile Matching ◽  
Using Data ◽  
Dna Profiles ◽  
Two Parameter

The “rare type match problem” is the situation in which, in a criminal case, the suspect’s DNA profile, matching the DNA profile of the crime stain, is not in the database of reference. Ideally, the evaluation of this observed match in the light of the two competing hypotheses (the crime stain has been left by the suspect or by another person) should be based on the calculation of the likelihood ratio and depends on the population proportions of the DNA profiles that are unknown. We propose a Bayesian nonparametric method that uses a two-parameter Poisson Dirichlet distribution as a prior over the ranked population proportions and discards the information about the names of the different DNA profiles. This model is validated using data coming from European Y-STR DNA profiles, and the calculation of the likelihood ratio becomes quite simple thanks to an Empirical Bayes approach for which we provided a motivation.

Forensic Statistics in Health Sciences

2011 ◽  
pp. 326-344
Author(s):  
Amit Chattopadhyay
Keyword(s):  
Clinical Practice ◽  
Statistical Analysis ◽  
Decision Analysis ◽  
Extreme Values ◽  
Health Sciences ◽  
Dna Profile ◽  
Profile Matching ◽  
Statistical Application ◽  
Dna Profiles

This chapter reviews the application of forensic statistical methods related issues such as: methods of deciphering evidence, DNA profile matching, searching a database of DNA profiles, scientific reliability, discrimination in presentation of statistical evidence in legal settings, assumptions in underlying statistical analysis when evidence is presented, precision & accuracy, role of using extreme values in evidence, and decision analysis in forensic science. The emphasis of the chapter is on concepts from statistical application, nature, and use of evidences in everyday clinical practice and in the court of law. Another goal of the chapter is to serve as a central reference to access of information about resources related to this topic.

scholarly journals DMSO Improves the Ski-Slope Effect in Direct PCR

2021 ◽  
Vol 11 (4) ◽  
pp. 1943
Author(s):  
Joo-Young Kim ◽  
Ju Yeon Jung ◽  
Da-Hye Kim ◽  
Seohyun Moon ◽  
Won-Hae Lee ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Pcr Amplification ◽  
Analytical Techniques ◽  
Direct Pcr ◽  
Dna Profile ◽  
Novel Technologies ◽  
Specific Amplification ◽  
Polymerase Chain ◽  
Dna Profiles

Analytical techniques such as DNA profiling are widely used in various fields, including forensic science, and novel technologies such as direct polymerase chain reaction (PCR) amplification are continuously being developed in order to acquire DNA profiles efficiently. However, non-specific amplification may occur depending on the quality of the crime scene evidence and amplification methods employed. In particular, the ski-slope effect observed in direct PCR amplification has led to inaccurate interpretations of the DNA profile results. In this study, we aimed to reduce the ski-slope effect by using dimethyl sulfoxide (DMSO) in direct PCR. We confirmed that DMSO (3.75%, v/v) increased the amplification yield of large-sized DNA sequences more than that of small-sized ones. Using 50 Korean buccal samples, we further demonstrated that DMSO reduced the ski-slope effect in direct PCR. These results suggest that the experimental method developed in this study is suitable for direct PCR and may help to successfully obtain DNA profiles from various types of evidence at crime scenes.

scholarly journals Gibbs partitions, Riemann–Liouville fractional operators, Mittag–Leffler functions, and fragmentations derived from stable subordinators

2021 ◽  
Vol 58 (2) ◽  
pp. 314-334
Author(s):  
Man-Wai Ho ◽  
Lancelot F. James ◽  
John W. Lau
Keyword(s):  
Special Functions ◽  
Dirichlet Distribution ◽  
Random Trees ◽  
Fractional Integrals ◽  
Biased Sampling ◽  
Scaling Limits ◽  
Fractional Operators ◽  
Random Partitions ◽  
Two Parameter ◽  
Potential Use

AbstractPitman (2003), and subsequently Gnedin and Pitman (2006), showed that a large class of random partitions of the integers derived from a stable subordinator of index $\alpha\in(0,1)$ have infinite Gibbs (product) structure as a characterizing feature. The most notable case are random partitions derived from the two-parameter Poisson–Dirichlet distribution, $\textrm{PD}(\alpha,\theta)$, whose corresponding $\alpha$-diversity/local time have generalized Mittag–Leffler distributions, denoted by $\textrm{ML}(\alpha,\theta)$. Our aim in this work is to provide indications on the utility of the wider class of Gibbs partitions as it relates to a study of Riemann–Liouville fractional integrals and size-biased sampling, and in decompositions of special functions, and its potential use in the understanding of various constructions of more exotic processes. We provide characterizations of general laws associated with nested families of $\textrm{PD}(\alpha,\theta)$ mass partitions that are constructed from fragmentation operations described in Dong et al. (2014). These operations are known to be related in distribution to various constructions of discrete random trees/graphs in [n], and their scaling limits. A centerpiece of our work is results related to Mittag–Leffler functions, which play a key role in fractional calculus and are otherwise Laplace transforms of the $\textrm{ML}(\alpha,\theta)$ variables. Notably, this leads to an interpretation within the context of $\textrm{PD}(\alpha,\theta)$ laws conditioned on Poisson point process counts over intervals of scaled lengths of the $\alpha$-diversity.

Conditional Genotypic Probabilities for Microsatellite Loci

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1973-1980
Author(s):  
Jinko Graham ◽  
James Curran ◽  
B S Weir
Keyword(s):  
Short Tandem Repeats ◽  
Tandem Repeats ◽  
Dirichlet Distribution ◽  
Forensic Dna ◽  
Match Probability ◽  
Microsatellite Genotype ◽  
Allelic State ◽  
Forensic Assessments ◽  
Dna Profiles ◽  
Short Tandem

Abstract Modern forensic DNA profiles are constructed using microsatellites, short tandem repeats of 2–5 bases. In the absence of genetic data on a crime-specific subpopulation, one tool for evaluating profile evidence is the match probability. The match probability is the conditional probability that a random person would have the profile of interest given that the suspect has it and that these people are different members of the same subpopulation. One issue in evaluating the match probability is population differentiation, which can induce coancestry among subpopulation members. Forensic assessments that ignore coancestry typically overstate the strength of evidence against the suspect. Theory has been developed to account for coancestry; assumptions include a steady-state population and a mutation model in which the allelic state after a mutation event is independent of the prior state. Under these assumptions, the joint allelic probabilities within a subpopulation may be approximated by the moments of a Dirichlet distribution. We investigate the adequacy of this approximation for profiled loci that mutate according to a generalized stepwise model. Simulations suggest that the Dirichlet theory can still overstate the evidence against a suspect with a common microsatellite genotype. However, Dirichlet-based estimators were less biased than the product-rule estimator, which ignores coancestry.

scholarly journals Autotetraploid Emergence via Somatic Embryogenesis in Vitis vinifera Induces Marked Morphological Changes in Shoots, Mature Leaves, and Stomata

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1336
Author(s):  
Caterina Catalano ◽  
Loredana Abbate ◽  
Antonio Motisi ◽  
Dalila Crucitti ◽  
Vincenzo Cangelosi ◽  
...  
Keyword(s):  
Somatic Embryogenesis ◽  
Morphological Changes ◽  
Ploidy Levels ◽  
Dna Profile ◽  
Morphological Alterations ◽  
Cell Pair ◽  
Mature Leaves ◽  
Induction Process ◽  
Ploidy Changes ◽  
Dna Profiles

Polyploidy plays an important role in plant adaptation to biotic and abiotic stresses. Alterations of the ploidy in grapevine plants regenerated via somatic embryogenesis (SE) may provide a source of genetic variability useful for the improvement of agronomic characteristics of crops. In the grapevine, the SE induction process may cause ploidy changes without alterations in DNA profile. In the present research, tetraploid plants were observed for 9.3% of ‘Frappato’ grapevine somatic embryos regenerated in medium supplemented with the growth regulators β-naphthoxyacetic acid (10 µM) and N6-benzylaminopurine (4.4 µM). Autotetraploid plants regenerated via SE without detectable changes in the DNA profiles were transferred in field conditions to analyze the effect of polyploidization. Different ploidy levels induced several anatomical and morphological changes of the shoots and mature leaves. Alterations have been also observed in stomata. The length and width of stomata of tetraploid leaves were 39.9 and 18.6% higher than diploids, respectively. The chloroplast number per guard cell pair was higher (5.2%) in tetraploid leaves. On the contrary, the stomatal index was markedly decreased (12%) in tetraploid leaves. The observed morphological alterations might be useful traits for breeding of grapevine varieties in a changing environment.

310/2020 Ministry of Science and Higher Education Ranking 20 pt. in category of journals listed on the ranking published by Ministry of Science and Higher Education. IC Journals Masters List 2019 94,04 pt. (Index Copernicus Value) Internal validation of LRmix Studio biostatistical software

2019 ◽  
Vol 306 ◽  
pp. 71-80
Author(s):  
Michał Boroń ◽  
◽  
Anna Brągoszewska ◽  
Keyword(s):  
Higher Education ◽  
Likelihood Ratio ◽  
Statistical Methods ◽  
Probabilistic Methods ◽  
Statistical Interpretation ◽  
Conditional Probabilities ◽  
Internal Validation ◽  
Dna Profile ◽  
Competing Hypotheses ◽  
Drop Outs

The source of DNA in a stain is never known with full certainty despite the fact that the evidential profile may match a DNA profile of a given person from the population. The statistical methods, including the likelihood ratio (LR) allow estimating the evidential power of the obtained result and assessing the ratio of the odds between competing hypotheses as to the origin of a DNA profile or mixture. Therefore using analyses based on probabilistic methods seems to be logically justified and allows reducing the subjectivism of interpretation of results. Thorough knowledge and understanding of the principles of operation and limitations of the tools used for statistical interpretation of the results of biological traces analyses in forensics is the key stage that precedes the formulation of conclusions. The process of checking the efficiency of LRmix Studio software as well as reliability and repeatability of results involved single profiles and mixtures from two and three persons. 1971 comparisons with referential profiles were performed. The correctness of generated conditional probabilities was determined and the limits, i.e. drop-outs number in the evidential profile whose exceeding might bring about false LR values were identified.

scholarly journals UK epidemic strains of meticillin-resistant Staphylococcus aureus in clinical samples from Malta

2008 ◽  
Vol 57 (11) ◽  
pp. 1394-1398 ◽  
Author(s):  
Simon W. J. Gould ◽  
Jess Rollason ◽  
Anthony C. Hilton ◽  
Paul Cuschieri ◽  
Laura McAuliffe ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Great Britain ◽  
Surveillance System ◽  
Clinical Samples ◽  
Geographical Distance ◽  
Pfge Analysis ◽  
Dna Profile ◽  
The Uk ◽  
Dna Profiles ◽  
Southern European Countries

Since 1999, the European Antimicrobial Resistance Surveillance System (EARSS) has monitored the rise in infection due to a number of organisms, including meticillin-resistant Staphylococcus aureus (MRSA). The EARSS reported that MRSA infections within intensive care units account for 25–50 % of infections in many central and southern European countries, these included France, Spain, Great Britain, Malta, Greece and Italy. Each country has defined epidemic MRSA (EMRSA) strains; however, the method of spread of these strains from one country to another is unknown. In this current study, DNA profiles of 473 isolates of MRSA collected from the UK and Malta were determined by PFGE. Analysis of the data showed that two countries separated by a large geographical distance had a similar DNA profile pattern. Additionally it was demonstrated that strains of EMRSA normally found in the UK were also found in the Maltese cohort (EMRSA 15 and 16). A distinct DNA profile was found in the Maltese cohort, which may be a local EMRSA, and accounted for 14.4 % of all Maltese isolates. The appearance of the same MRSA and EMRSA profiles in two separate countries suggests that MRSA can be transferred out of their country of origin and potentially establish in a new locality or country.

scholarly journals Spanish public awareness regarding DNA profile databases in forensic genetics: what type of DNA profiles should be included?

2007 ◽  
Vol 33 (10) ◽  
pp. 598-604 ◽  
Author(s):  
J. J Gamero ◽  
J.-L. Romero ◽  
J.-L. Peralta ◽  
M. Carvalho ◽  
F. Corte-Real
Keyword(s):  
Forensic Genetics ◽  
Public Awareness ◽  
Dna Profile ◽  
Dna Profiles
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