793 research outputs found
Raising: Dutch between English and German
As a complement to C. B. van Haeringen's classic comparative study (1956) that positioned the grammar of Dutch in between the grammars of English and German, this study compares the productivity of three kinds of "raising" patterns in these languages: Object-to-Subject, Subject-to-Object, and Subject-to-Subject raising. It establishes the extent to which Dutch, as well as English and German, have evolved from the old West Germanic starting point these languages are assumed to have shared in this area of grammar. The results are a test case for Hawkins' (1986) case syncretism account of the difference in "explicit-ness" between the grammars of English and German. © Society for Germanic Linguistics 2011.published_or_final_versio
Performance analysis of a parallel, multi-node pipeline for DNA sequencing
Post-sequencing DNA analysis typically consists of read mapping followed by variant calling and is very time-consuming, even on a multi-core machine. Recently, we proposed Halvade, a parallel, multi-node implementation of a DNA sequencing pipeline according to the GATK Best Practices recommendations. The MapReduce programming model is used to distribute the workload among different workers. In this paper, we study the impact of different hardware configurations on the performance of Halvade. Benchmarks indicate that especially the lack of good multithreading capabilities in the existing tools (BWA, SAMtools, Picard, GATK) cause suboptimal scaling behavior. We demonstrate that it is possible to circumvent this bottleneck by using multiprocessing on high-memory machines rather than using multithreading. Using a 15-node cluster with 360 CPU cores in total, this results in a runtime of 1 h 31 min. Compared to a single-threaded runtime of similar to 12 days, this corresponds to an overall parallel efficiency of 53%
Lossof a chloroplast encoded function could influence species range in kelp
Kelps are important providers and constituents of marine ecological niches, the
coastal kelp forests. Kelp species have differing distribution ranges, but mainly thrive
in temperate and arctic regions. Although the principal factors determining biogeographic
distribution ranges are known, genomics could provide additional answers to
this question.
We sequenced DNA from two Laminaria species with contrasting distribution
ranges, Laminaria digitata and Laminaria solidungula. Laminaria digitata is found in the
Northern Atlantic with a southern boundary in Brittany (France) or Massachusetts
(USA) and a northern boundary in the Arctic, whereas L. solidungula is endemic to the
Arctic only. From the raw reads of DNA, we reconstructed both chloroplast genomes
and annotated them. A concatenated data set of all available brown algae chloroplast
sequences was used for the calculation of a robust phylogeny, and sequence variations
were analyzed.
The two Laminaria chloroplast genomes are collinear to previously analyzed kelp
chloroplast genomes with important exceptions. Rearrangements at the inverted repeat
regions led to the pseudogenization of ycf37 in L. solidungula, a gene possibly
required under high light conditions. This defunct gene might be one of the reasons
why the habitat range of L. solidungula is restricted to lowlight sublittoral sites in the
Arctic. The inheritance pattern of single nucleotide polymorphisms suggests incomplete
lineage sorting of chloroplast genomes in kelp species.
Our analysis of kelp chloroplast genomes shows that not only evolutionary information
could be gleaned from sequence data. Concomitantly, those sequences can
also tell us something about the ecological conditions which are required for species
well‐being
Less is more: possibility and necessity as centres of gravity in a usage-based classification of core modals in Polish
In this paper we present the results of an empirical study into the cognitive reality of existing classifications of modality using Polish data. We analyzed random samples of 250 independent observations for the 7 most frequent modal words (móc, można, musieć, należy, powinien, trzeba, wolno), extracted from the Polish national corpus. Observations were annotated for modal type according to a number of classifications, including van der Auwera and Plungian (1998), as well as for morphological, syntactic and semantic properties using the Behavioral Profiling approach (Divjak and Gries 2006). Multiple correspondence analysis and (polytomous) regression models were used to determine how well modal type and usage align. These corpus-based findings were validated experimentally. In a forced choice task, naive native speakers were exposed to definitions and prototypical examples of modal types or functions, then labeled a number of authentic corpus sentences accordingly. In the sorting task, naive native speakers sorted authentic corpus sentences into semantically coherent groups. We discuss the results of our empirical study as well as the issues involved in building usage-based accounts on traditional linguistic classifications
Deep convergence, shared ancestry and evolutionary novelty in the genetic architecture of heliconius mimicry
Convergent evolution can occur through different genetic mechanisms in different species. It is now clear that convergence at the genetic level is also widespread, and can be caused by either (i) parallel genetic evolution, where independently evolved convergent mutations arise in different populations or species, or (ii) collateral evolution in which shared ancestry results from either ancestral polymorphism or introgression among taxa. The adaptive radiation of Heliconius butterflies shows color pattern variation within species, as well as mimetic convergence between species. Using comparisons from across multiple hybrid zones, we use signals of shared ancestry to identify and refine multiple putative regulatory elements in Heliconius melpomene and its comimics, Heliconius elevatus and Heliconius besckei, around three known major color patterning genes: optix, WntA, and cortex. While we find that convergence between H. melpomene and H. elevatus is caused by a complex history of collateral evolution via introgression in the Amazon, convergence between these species in the Guianas appears to have evolved independently. Thus, we find adaptive convergent genetic evolution to be a key driver of regulatory changes that lead to rapid phenotypic changes. Furthermore, we uncover evidence of parallel genetic evolution at some loci around optix and WntA in H. melpomene and its distant comimic Heliconius erato. Ultimately, we show that all three of convergence, conservation, and novelty underlie the modular architecture of Heliconius color pattern mimicry
Graves Hyperthyroidism After Stopping Immunosuppressive Therapy in Type 1 Diabetic Islet Cell Recipients With Pretransplant TPO Autoantibodies
OBJECTIVE — After an initially successful islet cell transplantation, a number of patients return to C-peptide negativity, and therefore immunosuppressive therapy is discontinued. Some are then found to have developed Graves disease. We examined the risk of Graves disease after immunosuppression. RESEARCHDESIGNANDMETHODS — Immunosuppressive therapy was stopped in 13 type 1 diabetic islet cell recipients who had received one course of antithymocyte globulin and maintenance doses of mycophenolate mofetil and a calcineurin inhibitor. None had a history of thyroid disease. RESULTS — In four patients, clinical Graves hyperthyroidism was observed within 21 months after discontinuation and 30–71 months after the start of immunosuppressive therapy. All four patients exhibited a pretransplant positivity for thyroid peroxidase (TPO) autoantibod-ies, while the nine others were TPO negative pre- and posttransplantation. CONCLUSIONS — Type 1 diabetic recipients of islet cell grafts with pretransplant TPO autoantibody positivity exhibit a high risk for developing Graves hyperthyroidism after immu-nosuppressive therapy is discontinued for a failing graft. Diabetes Care 32:1817–1819, 2009 I slet cell transplantation has beenshown to reproducibly achieve meta-bolic correction in nonuremic type 1 diabetic patients (1,2). However, in the years following transplantation, several of them return to C-peptide negativity and thus to a discontinuation of their immu-nosuppressive therapy (2)
Whole genome resequencing of a laboratory-adapted Drosophila melanogaster population sample
As part of a study into the molecular genetics of sexually dimorphic complex traits, we used high-throughput sequencing to obtain data on genomic variation in an outbred laboratory-adapted fruit fly (Drosophila melanogaster) population. We successfully resequenced the whole genome of 220 hemiclonal females that were heterozygous for the same Berkeley reference line genome (BDGP6/dm6), and a unique haplotype from the outbred base population (LHM). The use of a static and known genetic background enabled us to obtain sequences from whole-genome phased haplotypes. We used a BWA-Picard-GATK pipeline for mapping sequence reads to the dm6 reference genome assembly, at a median depth-of coverage of 31X, and have made the resulting data publicly-available in the NCBI Short Read Archive (Accession number SRP058502). We used Haplotype Caller to discover and genotype 1,726,931 small genomic variants (SNPs and indels, <200bp). Additionally we detected and genotyped 167 large structural variants (1-100Kb in size) using GenomeStrip/2.0. Sequence and genotype data are publicly-available at the corresponding NCBI databases: Short Read Archive, dbSNP and dbVar (BioProject PRJNA282591). We have also released the unfiltered genotype data, and the code and logs for data processing and summary statistics
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