115 research outputs found
Ontology based Scene Creation for the Development of Automated Vehicles
The introduction of automated vehicles without permanent human supervision
demands a functional system description, including functional system boundaries
and a comprehensive safety analysis. These inputs to the technical development
can be identified and analyzed by a scenario-based approach. Furthermore, to
establish an economical test and release process, a large number of scenarios
must be identified to obtain meaningful test results. Experts are doing well to
identify scenarios that are difficult to handle or unlikely to happen. However,
experts are unlikely to identify all scenarios possible based on the knowledge
they have on hand. Expert knowledge modeled for computer aided processing may
help for the purpose of providing a wide range of scenarios. This contribution
reviews ontologies as knowledge-based systems in the field of automated
vehicles, and proposes a generation of traffic scenes in natural language as a
basis for a scenario creation.Comment: Accepted at the 2018 IEEE Intelligent Vehicles Symposium, 8 pages, 10
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A restraint molecular dynamics and simulated annealing approach for protein homology modeling utilizing mean angles
BACKGROUND: We have developed the program PERMOL for semi-automated homology modeling of proteins. It is based on restrained molecular dynamics using a simulated annealing protocol in torsion angle space. As main restraints defining the optimal local geometry of the structure weighted mean dihedral angles and their standard deviations are used which are calculated with an algorithm described earlier by Döker et al. (1999, BBRC, 257, 348–350). The overall long-range contacts are established via a small number of distance restraints between atoms involved in hydrogen bonds and backbone atoms of conserved residues. Employing the restraints generated by PERMOL three-dimensional structures are obtained using standard molecular dynamics programs such as DYANA or CNS. RESULTS: To test this modeling approach it has been used for predicting the structure of the histidine-containing phosphocarrier protein HPr from E. coli and the structure of the human peroxisome proliferator activated receptor γ (Ppar γ). The divergence between the modeled HPr and the previously determined X-ray structure was comparable to the divergence between the X-ray structure and the published NMR structure. The modeled structure of Ppar γ was also very close to the previously solved X-ray structure with an RMSD of 0.262 nm for the backbone atoms. CONCLUSION: In summary, we present a new method for homology modeling capable of producing high-quality structure models. An advantage of the method is that it can be used in combination with incomplete NMR data to obtain reasonable structure models in accordance with the experimental data
Displaying Fel d1 on virus-like particles prevents reactogenicity despite greatly enhanced immunogenicity: a novel therapy for cat allergy
Allergen-specific desensitization is the only disease-modifying therapy currently available for the treatment of allergies. These therapies require application of allergen over several years and some may induce life-threatening anaphylactic reactions. An ideal vaccine for desensitization should be highly immunogenic and should alleviate allergic symptoms upon few injections while being nonreactogenic. We describe such a vaccine for the treatment of cat allergy, consisting of the major cat allergen Fel d1 coupled to bacteriophage Qβ-derived virus-like particles (Qβ–Fel d1). Qβ–Fel d1 was highly immunogenic, and a single vaccination was sufficient to induce protection against type I allergic reactions. Allergen-specific immunoglobulin G antibodies were shown to be the critical effector molecules and alleviated symptoms by two distinct mechanisms. Although allergen-induced systemic basophil degranulation was inhibited in an FcγRIIb-dependent manner, inhibition of local mast cell degranulation in tissues occurred independently of FcγRIIb. In addition, treatment with Qβ–Fel d1 abolished IgE memory responses upon antigen recall. Despite high immunogenicity, the vaccine was essentially nonreactogenic and vaccination induced neither local nor systemic anaphylactic reactions in sensitized mice. Moreover, Qβ–Fel d1 did not induce degranulation of basophils derived from human volunteers with cat allergies. These data suggest that vaccination with Qβ–Fel d1 may be a safe and effective treatment for cat allergy
Circulating KRAS G12D but not G12V is associated with survival in metastatic pancreatic ductal adenocarcinoma
While high circulating tumor DNA (ctDNA) levels are associated with poor survival for multiple cancers, variant-specific differences in the association of ctDNA levels and survival have not been examined. Here we investigate KRAS ctDNA (ctKRAS) variant-specific associations with overall and progression-free survival (OS/PFS) in first-line metastatic pancreatic ductal adenocarcinoma (mPDAC) for patients receiving chemoimmunotherapy ("PRINCE", NCT03214250), and an independent cohort receiving standard of care (SOC) chemotherapy. For PRINCE, higher baseline plasma levels are associated with worse OS for ctKRAS G12D (log-rank p = 0.0010) but not G12V (p = 0.7101), even with adjustment for clinical covariates. Early, on-therapy clearance of G12D (p = 0.0002), but not G12V (p = 0.4058), strongly associates with OS for PRINCE. Similar results are obtained for the SOC cohort, and for PFS in both cohorts. These results suggest ctKRAS G12D but not G12V as a promising prognostic biomarker for mPDAC and that G12D clearance could also serve as an early biomarker of response
Genome-wide association scan identifies new variants associated with a cognitive predictor of dyslexia
Developmental dyslexia (DD) is one of the most prevalent learning disorders, with high impact on school and psychosocial development and high comorbidity with conditions like attention-deficit hyperactivity disorder (ADHD), depression, and anxiety. DD is characterized by deficits in different cognitive skills, including word reading, spelling, rapid naming, and phonology. To investigate the genetic basis of DD, we conducted a genome-wide association study (GWAS) of these skills within one of the largest studies available, including nine cohorts of reading-impaired and typically developing children of European ancestry (N = 2562-3468). We observed a genome-wide significant effect (p < 1 x 10(-8)) on rapid automatized naming of letters (RANlet) for variants on 18q12.2, within MIR924HG (micro-RNA 924 host gene;rs17663182 p = 4.73 x 10(-9)), and a suggestive association on 8q12.3 within NKAIN3 (encoding a cation transporter;rs16928927, p = 2.25 x 10(-8)). rs17663182 (18q12.2) also showed genome-wide significant multivariate associations with RAN measures (p = 1.15 x 10(-8)) and with all the cognitive traits tested (p = 3.07 x 10(-8)), suggesting (relational) pleiotropic effects of this variant. A polygenic risk score (PRS) analysis revealed significant genetic overlaps of some of the DD-related traits with educational attainment (EDUyears) and ADHD. Reading and spelling abilities were positively associated with EDUyears (p similar to [10(-5)-10(-7)]) and negatively associated with ADHD PRS (p similar to [10(-8)-10(-17)]). This corroborates a long-standing hypothesis on the partly shared genetic etiology of DD and ADHD, at the genome-wide level. Our findings suggest new candidate DD susceptibility genes and provide new insights into the genetics of dyslexia and its comorbities
Genome-wide association scan identifies new variants associated with a cognitive predictor of dyslexia
Developmental dyslexia (DD) is one of the most prevalent learning disorders, with high impact on school and psychosocial development and high comorbidity with conditions like attention-deficit hyperactivity disorder (ADHD), depression, and anxiety. DD is characterized by deficits in different cognitive skills, including word reading, spelling, rapid naming, and phonology. To investigate the genetic basis of DD, we conducted a genome-wide association study (GWAS) of these skills within one of the largest studies available, including nine cohorts of reading-impaired and typically developing children of European ancestry (N = 2562-3468). We observed a genome-wide significant effect (p <1 x 10(-8)) on rapid automatized naming of letters (RANlet) for variants on 18q12.2, within MIR924HG (micro-RNA 924 host gene; rs17663182 p = 4.73 x 10(-9)), and a suggestive association on 8q12.3 within NKAIN3 (encoding a cation transporter; rs16928927, p = 2.25 x 10(-8)). rs17663182 (18q12.2) also showed genome-wide significant multivariate associations with RAN measures (p = 1.15 x 10(-8)) and with all the cognitive traits tested (p = 3.07 x 10(-8)), suggesting (relational) pleiotropic effects of this variant. A polygenic risk score (PRS) analysis revealed significant genetic overlaps of some of the DD-related traits with educational attainment (EDUyears) and ADHD. Reading and spelling abilities were positively associated with EDUyears (p similar to [10(-5)-10(-7)]) and negatively associated with ADHD PRS (p similar to [10(-8)-10(-17)]). This corroborates a long-standing hypothesis on the partly shared genetic etiology of DD and ADHD, at the genome-wide level. Our findings suggest new candidate DD susceptibility genes and provide new insights into the genetics of dyslexia and its comorbities.Peer reviewe
Genome-wide association study reveals new insights into the heritability and genetic correlates of developmental dyslexia
Developmental dyslexia (DD) is a learning disorder affecting the ability to read, with a heritability of 40-60%. A notable part of this heritability remains unexplained, and large genetic studies are warranted to identify new susceptibility genes and clarify the genetic bases of dyslexia. We carried out a genome-wide association study (GWAS) on 2274 dyslexia cases and 6272 controls, testing associations at the single variant, gene, and pathway level, and estimating heritability using single-nucleotide polymorphism (SNP) data. We also calculated polygenic scores (PGSs) based on large-scale GWAS data for different neuropsychiatric disorders and cortical brain measures, educational attainment, and fluid intelligence, testing them for association with dyslexia status in our sample. We observed statistically significant (p <2.8 x 10(-6)) enrichment of associations at the gene level, forLOC388780(20p13; uncharacterized gene), and forVEPH1(3q25), a gene implicated in brain development. We estimated an SNP-based heritability of 20-25% for DD, and observed significant associations of dyslexia risk with PGSs for attention deficit hyperactivity disorder (atp(T) = 0.05 in the training GWAS: OR = 1.23[1.16; 1.30] per standard deviation increase;p = 8 x 10(-13)), bipolar disorder (1.53[1.44; 1.63];p = 1 x 10(-43)), schizophrenia (1.36[1.28; 1.45];p = 4 x 10(-22)), psychiatric cross-disorder susceptibility (1.23[1.16; 1.30];p = 3 x 10(-12)), cortical thickness of the transverse temporal gyrus (0.90[0.86; 0.96];p = 5 x 10(-4)), educational attainment (0.86[0.82; 0.91];p = 2 x 10(-7)), and intelligence (0.72[0.68; 0.76];p = 9 x 10(-29)). This study suggests an important contribution of common genetic variants to dyslexia risk, and novel genomic overlaps with psychiatric conditions like bipolar disorder, schizophrenia, and cross-disorder susceptibility. Moreover, it revealed the presence of shared genetic foundations with a neural correlate previously implicated in dyslexia by neuroimaging evidence.Peer reviewe
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