Search results for "Variable"
showing 10 items of 1674 documents
Using the dglars Package to Estimate a Sparse Generalized Linear Model
2015
dglars is a publicly available R package that implements the method proposed in Augugliaro et al. (J. R. Statist. Soc. B 75(3), 471-498, 2013) developed to study the sparse structure of a generalized linear model (GLM). This method, called dgLARS, is based on a differential geometrical extension of the least angle regression method. The core of the dglars package consists of two algorithms implemented in Fortran 90 to efficiently compute the solution curve. dglars is a publicly available R package that implements the method proposed in Augugliaro et al. (J. R. Statist. Soc. B 75(3), 471-498, 2013) developed to study the sparse structure of a generalized linear model (GLM). This method, call…
Revealing Hidden Curvilinear Relations Between Work Engagement and Its Predictors: Demonstrating the Added Value of Generalized Additive Model (GAM)
2014
Previous studies measuring different aspects of the quality of life have, as a rule, presumed linear relationships between a dependent variable and its predictors. This article utilizes non-parametric statistical methodology to explore curvilinear relations between work engagement and its main predictors: job demands, job control and social support. Firstly, the study examines what additional information non-linear modeling can reveal regarding the relationship between work engagement and the three predictors in question. Secondly, the article compares the explanatory power of non-linear and linear modeling with regard to work engagement. The generalized additive model (GAM), that makes pos…
Bartlett formalism generating functions and Z-transforms in fluctuation and noise theory
1983
Abstract “La theorie des fonctions generatrices s'adapte elle meme et avec la plus grande generalite aux questions des probabilite les plus difficiles.” (Laplace, 1812) “An important part of probability theory consists of the derivation of the probability distribution of the sum of n random variables, each of which obeys a given probability law, and the development of asymptotic forms of these distributions valid for increasing n. Probability generating functions owe their dominant position to the simplification they permit to both problems. Their employment to obtain the successive moments of a probability distribution and to solve the difference equations of probability theory is ancillar…
Molecular epidemiology and forensic genetics: application to a hepatitis C virus transmission event at a hemodialysis unit.
2002
Molecular phylogenetic analyses are frequently used in epidemiologic testing, although only occasionally in forensics. Their acceptability is hampered by a lack of statistical confidence in the conclusions. However, maximum likelihood testing provides a sound statistical framework for the testing of phylogenetic hypotheses relevant for forensic analysis. We present the results of applying this method to a small hepatitis C outbreak produced in a hospital hemodialysis unit that involved 6 patients. Polymerase chain reaction products from a 472-nt fragment of the E1-E2 region, including the hypervariable region, HVR-1, of the hepatitis C virus genome were cloned, and an average of 10 clones/p…
Contribution of insertions and deletions to the variability of hepatitis C virus populations
2007
Little is known about the potential effects of insertions and deletions (indels) on the evolutionary dynamics of hepatitis C virus (HCV). In fact, the consequences of indels on antiviral treatment response are a field of investigation completely unexplored. Here, an extensive sequencing project was undertaken by cloning and sequencing serum samples from 25 patients infected with HCV subtype 1a and 48 patients with subtype 1b. For 23 patients, samples obtained after treatment with alpha interferon plus ribavirin were also available. Two genome fragments containing the hypervariable regions in the envelope 2 glycoprotein and the PKR-BD domain in NS5A were sequenced, yielding almost 16 000 seq…
Forensic animal DNA typing: Allele nomenclature and standardization of 14 feline STR markers
2014
Since the domestic cat (Felis catus) has become one of the most popular pets and owners usually develop a close relationship to their cats, it is necessary to take traces of cats into account for forensic casework. For this purpose feline short tandem (STR) repeat markers have been investigated in several earlier studies, but no detailed description of sequence data, allelic variations or a repeat-based nomenclature is available. The aim of the study was to provide a suggestion for the allele nomenclature of 14 cat STR markers according to the recommendations of the International Society for Forensic Genetics (ISFG) for human DNA typing and to present a standardized system for a secure DNA …
Range Shifts of Mouse Lemurs in South-Eastern Madagascar: Evidence from Mitochondrial Genetic Data
2012
The gray mouse lemur, Microcebus murinus, occurs mainly in dry forests in western Madagascar, but its distribution extends into humid littoral forests in the south-eastern Anosy Region. We sequenced the mitochondrial hypervariable region 1 for 282 M. murinus individuals from 13 south-eastern study sites. The spatial distribution of mitochondrial haplotypes and the varying genetic distances within two haplotype clades indicated a trend of decreasing genetic diversity towards the south-eastern margin of the range. Rufous mouse lemurs, Microcebus cf. rufus, have a complementary distribution in south-eastern Madagascar which does not overlap with that of M. murinus. Taken together, the spatial …
No association between two polymorphisms of the serotonin transporter gene and combined type attention deficit hyperactivity disorder.
2008
Contains fulltext : 71091.pdf (Publisher’s version ) (Closed access) Several independent studies have reported association between serotonin transporter gene (SLC6A4) polymorphisms and attention deficit hyperactivity disorder (ADHD). Five studies found evidence for association between the long-allele of a 44-bp insertion/deletion polymorphism (5-HTTLPR) and ADHD. Another two studies corroborated this finding while a further six studies did not find such an association. For a second polymorphism within the gene, a variable number tandem repeat (VNTR) within intron 2, one study demonstrated that the 12/12 genotype was significantly less frequent in ADHD cases compared to controls, while a sec…
Report of the European DNA profiling group (EDNAP)-an investigation of the hypervariable STR loci ACTBP2, APOAI1 and D11S554 and the compound loci D1…
1999
This paper describes the results of three collaborative exercises which continues the EDNAP theme to explore whether uniformity of DNA profiling results could be achieved between European laboratories using STRs. In an earlier exercise, complex hypervariable AAAG-repeat STR loci were investigated, but reproducibility was found to be poor because of the variation of techniques used by participating laboratories. In the exercise reported here, an internal allelic ladder composed of ACTBP2 and D11S554 fragments was distributed. This ladder was used to size ACTBP2 analysed by a "singleplex" PCR amplification and D11S554 combined with APOAI1 in a separate "duplex" reaction. Laboratories were ask…
The Association between a MAOB Variable Number Tandem Repeat Polymorphism and Cocaine and Opiate Addictions in Polyconsumers
2021
Genetic analysis of the association between alcohol, cocaine, and opiate addiction and variable number tandem repeat (VNTR) polymorphisms in monoamine oxidase B (MAOB) and serotonergic 5-hydroxytryptamine (serotonin) receptor 1B and 2C (HTR1B 21 and HTR2C) pathway genes was performed in a sample of 302 polyconsumers. Our genetic association analysis revealed a significant association between a 184 base pair (bp) VNTR polymorphism in the MAOB gene and addiction to cocaine and opiates. This work highlights new genetic marker associations in cocaine and opiate polyconsumer addictions. These data help to clarify and quantify the complex role of genetics in addictive disorders, as well as their …