scholarly journals Fitting the Balding-Nichols model to forensic databases

2014 ◽  
Author(s):  
Rori Rohlfs ◽  
Vitor R.C. Aguiar ◽  
Kirk E. Lohmueller ◽  
Amanda M. Castro ◽  
Alessandro C.S. Ferreira ◽  
...  
Keyword(s):  
Systematic Error ◽  
Genetic Models ◽  
Genotype Probability ◽  
Probability Estimates ◽  
Shared Ancestry ◽  
Forensic Genetic

Large forensic databases provide an opportunity to compare observed empirical rates of genotype matching with those expected under forensic genetic models. A number of researchers have taken advantage of this opportunity to validate some forensic genetic approaches, particularly to ensure that estimated rates of genotype matching between unrelated individuals are indeed slight overestimates of those observed. However, these studies have also revealed systematic error trends in genotype probability estimates. In this analysis, we investigate these error trends and show how they result from inappropriate implementation of the Balding-Nichols model in the context of database-wide matching. Specifically, we show that in addition to accounting for increased allelic matching between individuals with recent shared ancestry, studies must account for relatively decreased allelic matching between individuals with more ancient shared ancestry.

Disentangling the role of shared ancestry and the environment on leaf stable isotopes

2019 ◽  
Author(s):  
Marko J. Spasojevic ◽  
Sören Weber1
Keyword(s):  
Stable Isotopes ◽  
Environmental Conditions ◽  
Evolutionary History ◽  
Environmental Control ◽  
Phylogenetic Signal ◽  
Individual Species ◽  
Habitat Types ◽  
Δ13c And Δ15n ◽  
Environmental Controls ◽  
Shared Ancestry

Stable carbon (C) and nitrogen (N) isotopes in plants are important indicators of plant water use efficiency and N acquisition strategies. While often regarded as being under environmental control, there is growing evidence that evolutionary history may also shape variation in stable isotope ratios (δ13C and δ15N) among plant species. Here we examined patterns of foliar δ13C and δ15N in alpine tundra for 59 species in 20 plant families. To assess the importance of environmental controls and evolutionary history, we examined if average δ13C and δ15N predictably differed among habitat types, if individual species exhibited intraspecific trait variation (ITV) in δ13C and δ15N, and if there were a significant phylogenetic signal in δ13C and δ15N. We found that variation among habitat types in both δ13C and δ15N mirrored well-known patterns of water and nitrogen limitation. Conversely, we also found that 40% of species exhibited no ITV in δ13C and 35% of species exhibited no ITV in δ15N, suggesting that some species are under stronger evolutionary control. However, we only found a modest signal of phylogenetic conservatism in δ13C and no phylogenetic signal in δ15N suggesting that shared ancestry is a weaker driver of tundra wide variation in stable isotopes. Together, our results suggest that both evolutionary history and local environmental conditions play a role in determining variation in δ13C and δ15N and that considering both factors can help with interpreting isotope patterns in nature and with predicting which species may be able to respond to rapidly changing environmental conditions.

Systematic error of LSM-estimation of covariance components of biperiodically correlated random signals

2019 ◽  
Vol 2019 (47) ◽  
pp. 26-33
Author(s):  
I. M. Javorskyj ◽  
◽  
O. Y. Dzeryn ◽  
R. M. Yuzefovych ◽  
◽  
...  
Keyword(s):  
Systematic Error ◽  
Covariance Components ◽  
Random Signals

Employers and the 1881 Population Census of England and Wales

2015 ◽  
pp. 29-49 ◽  
Author(s):  
Robert J. Bennett ◽  
Gill Newton
Keyword(s):  
Systematic Error ◽  
Size Distribution ◽  
Firm Size ◽  
Extraction Method ◽  
Building Industry ◽  
Population Census ◽  
Firm Size Distribution ◽  
England And Wales ◽  
Occupational Information ◽  
First Results

This article presents the method and first results of using the 1881 England and Wales Census Enumerators' Books (CEBs) to identify and extract employer records using occupational information. Over 230,000 employers are identified, of which about four fifths employ others. Important sub-groups are also identified of the own account selfemployed, company proprietors, directors and partnerships. The article demonstrates the feasibility of the method and uses the example of the building industry to illustrate firm-size distribution at parish level across England and Wales. The paper indicates the applicability of the extraction method to other censuses, which is now possible using the recently released I-CeM database. The paper also demonstrates some difficulties in the database for 1881, including data keying and coding errors, ranging from 0.5 to 5.5 per cent of entries for larger businesses. Gender miscoding appears to be a systematic error of about 0.7 per 1,000 people. The analysis suggests that where small or atypical sample groups are involved, users of the census database should make detailed checks with manuscript CEBs.

Simulation Comparisons of Effectiveness among QTL Mapping Procedures of Different Statistical Genetic Models

2010 ◽  
Vol 36 (7) ◽  
pp. 1100-1107 ◽  
Author(s):  
Cheng-Fu SU ◽  
Tuan-Jie ZHAO ◽  
Jun-Yi GAI
Keyword(s):  
Qtl Mapping ◽  
Genetic Models
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