112 research outputs found
Deterministically and Sudoku-Deterministically Recognizable Picture Languages
The recognizable 2-dimensional languages are a robust class with many characterizations, comparable to the regular languages in the 1-dimensional case. One characterization is by tiling systems. The corresponding word problem is NP-complete. Therefore, notions of determinism for tiling systems were suggested. For the notion which was called "deterministically recognizable"
it was open since 1998 whether it implies recognizability.
By showing that acyclicity of grid graphs is recognizable we answer this question positively.
In contrast to that, we show that non-recognizable languages can be accepted by a generalization of this tiling system determinism which we call sudoku-determinism.
Its word problem, however, is still in linear time.
We show that Sudoku-determinism even contains the set of 2-dimensional languages which can be recognized by
4-way alternating automata
Searching paths of constant bandwidth
As a generalization of paths, the notion of paths of bandwidth w is introduced. We show that, for a given constant w >= 1, the corresponding search problem for such a path of length k in a given graph is NP-complete and fixed-parameter tractable in the parameter k, like this is known for the special case w=1, the LONGEST PATH problem. We state the FPT algorithm in terms of a guess and check protocol which uses witnesses of size polynomial in the parameter
Exponential Multiplication Schemes
We present an idea to describe a polynomial with 2^n distinct integer zeros by an n-tuple of integers via a scheme of n recurring equations.
We call such an n-tuple an exponential multiplication scheme of size n. Exponential multiplication schemes of size 1,2,3, and 4 are presented.
Under the assumption that fast exponential multiplication scheme generators exist we suggest a fast randomized heuristic for the factorization problem
Construct Validity, Test-Retest Reliability, and Internal Consistency of the Photo Elicitation Semantic Differential Scale (PESD) in Disability Studies
The Photo Elicitation Semantic Differential scale (PESD), developed to examine the social perception of disability and attitudes towards people with a disability (PwD), comprises six dimensions: communicativeness, competence, attractiveness, intelligence, industriousness, and popularity. This paper aims to assess the construct validity, test-retest reliability, and internal consistency of the PESD. A longitudinal study with 40 participants of the Swiss general population and 2 (test-retest) * 8 (different photographs) measurements per subject was performed. Construct validity was examined via Principal Component Analysis (PCA), test-retest reliability via the Intraclass Correlation Coefficient (ICC) and a frequency analysis of deviations among test-retest scores, and internal consistency via Cronbach's alpha. PCA extracted two factors corresponding to hard and soft skills for the test and a single factor for the retest. ICCs ranged from 0.44 (industriousness) to 0.60 (intelligence). Deviations between tests exceeding +/-1 were rather rare ranging from 6% (intelligence) to 14% (competence). Cronbach's alpha equalled 0.814 and 0.858 for test and retest, respectively. Summarising, in our study the PESD appears to be a valid and reliable tool for the examination of the social perception of disability and attitudes towards Pw
Directed sequencing and annotation of three Dicentrarchus labrax L. chromosomes by applying Sanger- and pyrosequencing technologies on pooled DNA of comparatively mapped BAC clones
AbstractDicentrarchus labrax is one of the major marine aquaculture species in the European Union. In this study, we have developed a directed-sequencing strategy to sequence three sea bass chromosomes and compared results with other teleosts.Three BAC DNA pools were created from sea bass BAC clones that mapped to stickleback chromosomes/groups V, XVII and XXI. The pools were sequenced to 17–39x coverage by pyrosequencing. Data assembly was supported by Sanger reads and mate pair data and resulted in superscaffolds of 13.2Mb, 17.5Mb and 13.7Mb respectively. Annotation features of the superscaffolds include 1477 genes. We analyzed size change of exon, intron and intergenic sequence between teleost species and deduced a simple model for the evolution of genome composition in teleost lineage.Combination of second generation sequencing technologies, Sanger sequencing and genome partitioning strategies allows “high-quality draft assemblies” of chromosome-sized superscaffolds, which are crucial for the prediction and annotation of complete genes
Functioning and disability in people living with spinal cord injury in high- and low-resourced countries: a comparative analysis of 14 countries
Objectives: We examined whether persons with spinal cord injury (SCI) from countries with differential resources and resource distribution differ in the level and structure of functioning and disability. Methods: We analysed cross-sectional data of 1,048 persons with SCI from 14 countries based on the International Classification of Functioning, Disability and Health (ICF). We used penalized logistic regression to identify ICF categories distinguishing lower- and higher-resourced countries. Hierarchical linear models were employed to predict the number of problems in functioning. The association structure of ICF categories was compared between higher- and lower-resourced countries using graphical models. Results: A total of 96 ICF categories separated lower- and higher-resourced countries. Differences were not univocal. Lower resources and unequal distribution were predictive of more functional problems in persons with higher age or tetraplegia. In the graphical models, few associations between ICF categories persisted across countries. Conclusion: Higher-resourced countries do not score higher in all ICF categories. Countries' economic resources and their distribution are significant predictors of disability in vulnerable groups such as tetraplegics and the elderly. Functioning is multi-dimensional and structures of association suggest that country-specific pathways towards disability exis
Protein disulfide isomerase acts as an injury response signal that enhances fibrin generation via tissue factor activation
The activation of initiator protein tissue factor (TF) is likely to be a crucial step in the blood coagulation process, which leads to fibrin formation. The stimuli responsible for inducing TF activation are largely undefined. Here we show that the oxidoreductase protein disulfide isomerase (PDI) directly promotes TF-dependent fibrin production during thrombus formation in vivo. After endothelial denudation of mouse carotid arteries, PDI was released at the injury site from adherent platelets and disrupted vessel wall cells. Inhibition of PDI decreased TF-triggered fibrin formation in different in vivo murine models of thrombus formation, as determined by intravital fluorescence microscopy. PDI infusion increased — and, under conditions of decreased platelet adhesion, PDI inhibition reduced — fibrin generation at the injury site, indicating that PDI can directly initiate blood coagulation. In vitro, human platelet–secreted PDI contributed to the activation of cryptic TF on microvesicles (microparticles). Mass spectrometry analyses indicated that part of the extracellular cysteine 209 of TF was constitutively glutathionylated. Mixed disulfide formation contributed to maintaining TF in a state of low functionality. We propose that reduced PDI activates TF by isomerization of a mixed disulfide and a free thiol to an intramolecular disulfide. Our findings suggest that disulfide isomerases can act as injury response signals that trigger the activation of fibrin formation following vessel injury
The linear chromosome of the plant-pathogenic mycoplasma 'Candidatus Phytoplasma mali'
BACKGROUND: Phytoplasmas are insect-transmitted, uncultivable bacterial plant pathogens that cause diseases in hundreds of economically important plants. They represent a monophyletic group within the class Mollicutes (trivial name mycoplasmas) and are characterized by a small genome with a low GC content, and the lack of a firm cell wall. All mycoplasmas, including strains of 'Candidatus (Ca.) Phytoplasma asteris' and 'Ca. P. australiense', examined so far have circular chromosomes, as is the case for almost all walled bacteria. RESULTS: Our work has shown that 'Ca. Phytoplasma mali', the causative agent of apple proliferation disease, has a linear chromosome. Linear chromosomes were also identified in the closely related provisional species 'Ca. P. pyri' and 'Ca. P. prunorum'. The chromosome of 'Ca. P. mali' strain AT is 601,943 bp in size and has a GC content of 21.4%. The chromosome is further characterized by large terminal inverted repeats and covalently closed hairpin ends. Analysis of the protein-coding genes revealed that glycolysis, the major energy-yielding pathway supposed for 'Ca. P. asteris', is incomplete in 'Ca. P. mali'. Due to the apparent lack of other metabolic pathways present in mycoplasmas, it is proposed that maltose and malate are utilized as carbon and energy sources. However, complete ATP-yielding pathways were not identified. 'Ca. P. mali' also differs from 'Ca. P. asteris' by a smaller genome, a lower GC content, a lower number of paralogous genes, fewer insertions of potential mobile DNA elements, and a strongly reduced number of ABC transporters for amino acids. In contrast, 'Ca. P. mali' has an extended set of genes for homologous recombination, excision repair and SOS response than 'Ca. P. asteris'. CONCLUSION: The small linear chromosome with large terminal inverted repeats and covalently closed hairpin ends, the extremely low GC content and the limited metabolic capabilities reflect unique features of 'Ca. P. mali', not only within phytoplasmas, but all mycoplasmas. It is expected that the genome information obtained here will contribute to a better understanding of the reduced metabolism of phytoplasmas, their fastidious nutrition requirements that prevented axenic cultivation, and the mechanisms involved in pathogenicity
Chromosome-level sequence assembly reveals the structure of the Arabidopsis thaliana Nd-1 genome and its gene set
Pucker B, Holtgräwe D, Stadermann KB, et al. Chromosome-level sequence assembly reveals the structure of the Arabidopsis thaliana Nd-1 genome and its gene set. PLoS One. 2019;14(5): e0216233.In addition to the BAC-based reference sequence of the accession Columbia-0 from the year 2000, several short read assemblies of THE plant model organism Arabidopsis thaliana were published during the last years. Also, a SMRT-based assembly of Landsberg erecta has been generated that identified translocation and inversion polymorphisms between two genotypes of the species. Here we provide a chromosome-arm level assembly of the A. thaliana accession Niederzenz-1 (AthNd-1_v2c) based on SMRT sequencing data. The best assembly comprises 69 nucleome sequences and displays a contig length of up to 16 Mbp. Compared to an earlier Illumina short read-based NGS assembly (AthNd-1_v1), a 75 fold increase in contiguity was observed for AthNd-1_v2c. To assign contig locations independent from the Col-0 gold standard reference sequence, we used genetic anchoring to generate a de novo assembly. In addition, we assembled the chondrome and plastome sequences. Detailed analyses of AthNd-1_v2c allowed reliable identification of large genomic rearrangements between A. thaliana accessions contributing to differences in the gene sets that distinguish the genotypes. One of the differences detected identified a gene that is lacking from the Col-0 gold standard sequence. This de novo assembly extends the known proportion of the A. thaliana pan-genome
Recycling of Li-Ion Batteries from Industrial Processing: Upscaled Hydrometallurgical Treatment and Recovery of High Purity Manganese by Solvent Extraction
Manganese plays a central role in lithium-ion batteries (LIBs) but its recycling is rarely addressed when compared to other valuable metals present in LIBs, such as Co and Ni. Thus, the main goal of this work was to study and achieve the separation of Mn from Co and Ni by solvent extraction from a leachate obtained from LIBs using hydrochloric acid in an upscaled reactor, which is an innovative aspect of this work. The results confirmed the high selectivity of D2EHPA towards Mn, which could be completely extracted in two stages (0.5 M D2EHPA at pH 2.5). The main co-extracted metals were Al, Cu and Co, but with lower concentrations than Mn. The behavior of minor impurities such as Zn and Mg was also monitored. Scrubbing using manganese chloride was crucial to remove impurities from the loaded organic and prevent their presence in the stripping product, and high O:A ratios negatively affected the scrubbing efficiency. Keeping the concentration of HCl up to 0.5 M in the stripping stage helped to limit the stripping of impurities. Manganese oxide was precipitated as a product with 99.5% purity (with traces of Zn, Cu and Co), which could be reused in the battery value chain
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