Author
Erik Johansson
Other affiliations: University of Illinois at Urbana–Champaign, Swedish Defence Research Agency, Washington University in St. Louis
Bio: Erik Johansson is an academic researcher from Umeå University. The author has contributed to research in topics: DNA polymerase & DNA replication. The author has an hindex of 50, co-authored 114 publications receiving 9437 citations. Previous affiliations of Erik Johansson include University of Illinois at Urbana–Champaign & Swedish Defence Research Agency.
Papers published on a yearly basis
Papers
More filters
TL;DR: Room-temperature drift mobilities have been measured in high-purity single-crystal diamond grown using a chemical vapor deposition process and the reproducibility of those properties are encouraging for research on, and development of, high-performance diamond electronics.
Abstract: Room-temperature drift mobilities of 4500 square centimeters per volt second for electrons and 3800 square centimeters per volt second for holes have been measured in high-purity single-crystal diamond grown using a chemical vapor deposition process. The low-field drift mobility values were determined by using the time-of-flight technique on thick, intrinsic, freestanding diamond plates and were verified by current-voltage measurements on p-i junction diodes. The improvement of the electronic properties of single-crystal diamond and the reproducibility of those properties are encouraging for research on, and development of, high-performance diamond electronics.
1,064 citations
01 Jan 1984
TL;DR: In this paper, the authors propose a bilinear projection method for chemical tables, where the data table rows (objects) are represented as points in a p-dimensional space, and the point swarm of the data set or parts of it is projected down on a F-dimensional subspace (plane or hyperplane).
Abstract: Any data table produced in a chemical investigation can be analysed by bilinear projection methods, i. e. principal components and factor analysis and their extensions. Representing the table rows (objects) as points in a p-dimensional space, these methods project the point swarm of the data set or parts of it down on a F-dimensional subspace (plane or hyperplane). Different questions put to the data table correspond to different projections.
581 citations
TL;DR: A derivative of yeast DNA polymerase ϵ is constructed that retains high replication activity but has strongly reduced replication fidelity, particularly for thymine-deoxythymidine 5'-monophosphate (T-dTMP) but not adenine-deoxyadenosine 5-monoph phosphate (A-dAMP) mismatches.
Abstract: Multiple DNA polymerases participate in replicating the leading and lagging strands of the eukaryotic nuclear genome. Although 50 years have passed since the first DNA polymerase was discovered, the identity of the major polymerase used for leading-strand replication is uncertain. We constructed a derivative of yeast DNA polymerase ϵ that retains high replication activity but has strongly reduced replication fidelity, particularly for thymine-deoxythymidine 59-monophosphate (T-dTMP) but not adenine-deoxyadenosine 59-monophosphate (A-dAMP) mismatches. Yeast strains with this DNA polymerase ϵ allele have elevated rates of T to A substitution mutations. The position and rate of these substitutions depend on the orientation of the mutational reporter and its location relative to origins of DNA replication and reveal a pattern indicating that DNA polymerase ϵ participates in leading-strand DNA replication.
499 citations
TL;DR: Measurements of nucleoside triphosphate levels in Saccharomyces cerevisiae reveal that the four rNTPs are in 36- to 190-fold molar excess over their corresponding dNTBs, consistent with the possibility that more than 10,000 rNMPs may be incorporated into the nuclear genome during each round of replication in yeast.
Abstract: Measurements of nucleoside triphosphate levels in Saccharomyces cerevisiae reveal that the four rNTPs are in 36- to 190-fold molar excess over their corresponding dNTPs. During DNA synthesis in vitro using the physiological nucleoside triphosphate concentrations, yeast DNA polymerase e, which is implicated in leading strand replication, incorporates one rNMP for every 1,250 dNMPs. Pol δ and Pol α, which conduct lagging strand replication, incorporate one rNMP for every 5,000 or 625 dNMPs, respectively. Discrimination against rNMP incorporation varies widely, in some cases by more than 100-fold, depending on the identity of the base and the template sequence context in which it is located. Given estimates of the amount of replication catalyzed by Pols α, δ, and e, the results are consistent with the possibility that more than 10,000 rNMPs may be incorporated into the nuclear genome during each round of replication in yeast. Thus, rNMPs may be the most common noncanonical nucleotides introduced into the eukaryotic genome. Potential beneficial and negative consequences of abundant ribonucleotide incorporation into DNA are discussed, including the possibility that unrepaired rNMPs in DNA could be problematic because yeast DNA polymerase e has difficulty bypassing a single rNMP present within a DNA template.
383 citations
Cited by
More filters
TL;DR: Principal Component Analysis is a multivariate exploratory analysis method useful to separate systematic variation from noise and to define a space of reduced dimensions that preserve noise.
8,660 citations
TL;DR: PLS-regression (PLSR) as mentioned in this paper is the PLS approach in its simplest, and in chemistry and technology, most used form (two-block predictive PLS) is a method for relating two data matrices, X and Y, by a linear multivariate model.
7,861 citations
TL;DR: This work speculates on the reasons behind this large discrepancy between the expectations arising from proteomics and the realities of clinical diagnostics and suggests approaches by which protein-disease associations may be more effectively translated into diagnostic tools in the future.
4,062 citations
Book•
17 May 2013
TL;DR: This research presents a novel and scalable approach called “Smartfitting” that automates the very labor-intensive and therefore time-heavy and therefore expensive and expensive process of designing and implementing statistical models for regression models.
Abstract: General Strategies.- Regression Models.- Classification Models.- Other Considerations.- Appendix.- References.- Indices.
3,672 citations
University of Nottingham1, Rothamsted Research2, National Center for Toxicological Research3, University of Louisville4, Max Planck Society5, University of Manchester6, University of Cambridge7, Leiden University8, Aberystwyth University9, United States Department of Agriculture10, Imperial College London11, RMIT University12, GlaxoSmithKline13, Pfizer14, University of Arkansas for Medical Sciences15, University of Birmingham16
TL;DR: This article proposes the minimum reporting standards related to the chemical analysis aspects of metabolomics experiments including: sample preparation, experimental analysis, quality control, metabolite identification, and data pre-processing.
Abstract: There is a general consensus that supports the need for standardized reporting of metadata or information describing large-scale metabolomics and other functional genomics data sets. Reporting of standard metadata provides a biological and empirical context for the data, facilitates experimental replication, and enables the re-interrogation and comparison of data by others. Accordingly, the Metabolomics Standards Initiative is building a general consensus concerning the minimum reporting standards for metabolomics experiments of which the Chemical Analysis Working Group (CAWG) is a member of this community effort. This article proposes the minimum reporting standards related to the chemical analysis aspects of metabolomics experiments including: sample preparation, experimental analysis, quality control, metabolite identification, and data pre-processing. These minimum standards currently focus mostly upon mass spectrometry and nuclear magnetic resonance spectroscopy due to the popularity of these techniques in metabolomics. However, additional input concerning other techniques is welcomed and can be provided via the CAWG on-line discussion forum at http://msi-workgroups.sourceforge.net/ or http://Msi-workgroups-feedback@lists.sourceforge.net. Further, community input related to this document can also be provided via this electronic forum.
3,301 citations