Katholieke Universiteit Leuven

About: Katholieke Universiteit Leuven is a education organization based out in Leuven, Belgium. It is known for research contribution in the topics: Population & Transplantation. The organization has 61109 authors who have published 176584 publications receiving 6210872 citations.

Personal Epistemology: The Psychology of Beliefs About Knowledge and Knowing

Abstract: Contents: Preface. Introduction. B.K. Hofer, Personal Epistemology as a Psychological and Educational Construct: An Introduction. Part I: Conceptual Models of Personal Epistemology. W.S. Moore, Understanding Learning in a Postmodern World: Reconsidering the Perry Scheme of Ethical and Intellectual Development. P.M. King, K.S. Kitchener, The Reflective Judgment Model: Twenty Years of Research on Epistemic Cognition. B.M. Clinchy, Revisiting Women's Ways of Knowing. M.B.B. Magolda, Epistemological Reflection: The Evolution of Epistemological Assumptions From Age 18 to 30. M. Schommer-Aikins, An Evolving Theoretical Framework for an Epistemological Belief System. Part II: Theoretical and Conceptual Issues. D. Kuhn, M. Weinstock, What Is Epistemological Thinking and Why Does It Matter? M.J. Chandler, D. Hallett, B.W. Sokol, Competing Claims About Competing Knowledge Claims. D. Hammer, A. Elby, On the Form of a Personal Epistemology. L.D. Bendixen, A Process Model of Epistemic Belief Change. J. Fitzgerald, J.W. Cunningham, Mapping Basic Issues for Identifying Epistemological Outlooks. Part III: Methodological Issues in the Study of Personal Epistemology. P. Wood, C. Kardash, Critical Elements in the Design and Analysis of Studies of Epistemology. G. Schraw, L.D. Bendixen, M.E. Dunkle, Development and Validation of the Epistemic Belief Inventory (EBI). P. Wood, K. Kitchener, L. Jensen, Considerations in the Design and Evaluation of a Paper-and-Pencil Measure of Epistemic Cognition. Part IV: Perspectives on Discipline-Specific Epistemology. E. De Corte, P.O. Eynde, L. Verschaffel, "Knowing What to Believe": The Relevance of Students' Mathematical Beliefs for Mathematics Education. P. Bell, M.C. Linn, Beliefs About Science: How Does Science Instruction Contribute? A.D. Elder, Characterizing Fifth-Grade Students' Epistemological Beliefs in Science. G. Qian, J. Pan, A Comparison of Epistemological Beliefs and Learning From Science Text Between American and Chinese High School Students. P.R. Pintrich, Conclusion: Future Challenges and Directions for Theory and Research on Personal Epistemology.

Genome-wide association study identifies 74 loci associated with educational attainment

Abstract: Educational attainment is strongly influenced by social and other environmental factors, but genetic factors are estimated to account for at least 20% of the variation across individuals. Here we report the results of a genome-wide association study (GWAS) for educational attainment that extends our earlier discovery sample of 101,069 individuals to 293,723 individuals, and a replication study in an independent sample of 111,349 individuals from the UK Biobank. We identify 74 genome-wide significant loci associated with the number of years of schooling completed. Single-nucleotide polymorphisms associated with educational attainment are disproportionately found in genomic regions regulating gene expression in the fetal brain. Candidate genes are preferentially expressed in neural tissue, especially during the prenatal period, and enriched for biological pathways involved in neural development. Our findings demonstrate that, even for a behavioural phenotype that is mostly environmentally determined, a well-powered GWAS identifies replicable associated genetic variants that suggest biologically relevant pathways. Because educational attainment is measured in large numbers of individuals, it will continue to be useful as a proxy phenotype in efforts to characterize the genetic influences of related phenotypes, including cognition and neuropsychiatric diseases.

SCENIC: Single-Cell Regulatory Network Inference And Clustering

Abstract: Single-cell RNA-seq allows building cell atlases of any given tissue and infer the dynamics of cellular state transitions during developmental or disease trajectories. Both the maintenance and transitions of cell states are encoded by regulatory programs in the genome sequence. However, this regulatory code has not yet been exploited to guide the identification of cellular states from single-cell RNA-seq data. Here we describe a computational resource, called SCENIC (Single Cell rEgulatory Network Inference and Clustering), for the simultaneous reconstruction of gene regulatory networks (GRNs) and the identification of stable cell states, using single-cell RNA-seq data. SCENIC outperforms existing approaches at the level of cell clustering and transcription factor identification. Importantly, we show that cell state identification based on GRNs is robust towards batch-effects and technical-biases. We applied SCENIC to a compendium of single-cell data from the mouse and human brain and demonstrate that the proper combinations of transcription factors, target genes, enhancers, and cell types can be identified. Moreover, we used SCENIC to map the cell state landscape in melanoma and identified a gene regulatory network underlying a proliferative melanoma state driven by MITF and STAT and a contrasting network controlling an invasive state governed by NFATC2 and NFIB. We further validated these predictions by showing that two transcription factors are predominantly expressed in early metastatic sentinel lymph nodes. In summary, SCENIC is the first method to analyze scRNA-seq data using a network-centric, rather than cell-centric approach. SCENIC is generic, easy to use, and flexible, and allows for the simultaneous tracing of genomic regulatory programs and the mapping of cellular identities emerging from these programs. Availability: SCENIC is available as an R workflow based on three new R/Bioconductor packages: GENIE3, RcisTarget and AUCell. As scalable alternative to GENIE3, we also provide GRNboost, paving the way towards the network analysis across millions of single cells.

Common Genetic Variation In Cellular Transport Genes and Epithelial Ovarian Cancer (EOC) Risk

Abstract: BACKGROUND: Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. As DNA damage and uncontrolled proliferation are hallmarks of cancer, including epithelial ovarian cancer (EOC), we hypothesized that inherited variation in the cellular transport genes contributes to EOC risk. METHODS: In total, DNA samples were obtained from 14,525 case subjects with invasive EOC and from 23,447 controls from 43 sites in the Ovarian Cancer Association Consortium (OCAC). Two hundred seventy nine SNPs, representing 131 genes, were genotyped using an Illumina Infinium iSelect BeadChip as part of the Collaborative Oncological Gene-environment Study (COGS). SNP analyses were conducted using unconditional logistic regression under a log-additive model, and the FDR q<0.2 was applied to adjust for multiple comparisons. RESULTS: The most significant evidence of an association for all invasive cancers combined and for the serous subtype was observed for SNP rs17216603 in the iron transporter gene HEPH (invasive: OR = 0.85, P = 0.00026; serous: OR = 0.81, P = 0.00020); this SNP was also associated with the borderline/low malignant potential (LMP) tumors (P = 0.021). Other genes significantly associated with EOC histological subtypes (p<0.05) included the UGT1A (endometrioid), SLC25A45 (mucinous), SLC39A11 (low malignant potential), and SERPINA7 (clear cell carcinoma). In addition, 1785 SNPs in six genes (HEPH, MGST1, SERPINA, SLC25A45, SLC39A11 and UGT1A) were imputed from the 1000 Genomes Project and examined for association with INV EOC in white-European subjects. The most significant imputed SNP was rs117729793 in SLC39A11 (per allele, OR = 2.55, 95% CI = 1.5-4.35, p = 5.66x10-4). CONCLUSION: These results, generated on a large cohort of women, revealed associations between inherited cellular transport gene variants and risk of EOC histologic subtypes.

Revascularization of ischemic tissues by PlGF treatment, and inhibition of tumor angiogenesis, arthritis and atherosclerosis by anti-Flt1

Abstract: The therapeutic potential of placental growth factor (PlGF) and its receptor Flt1 in angiogenesis is poorly understood. Here, we report that PlGF stimulated angiogenesis and collateral growth in ischemic heart and limb with at least a comparable efficiency to vascular endothelial growth factor (VEGF). An antibody against Flt1 suppressed neovascularization in tumors and ischemic retina, and angiogenesis and inflammatory joint destruction in autoimmune arthritis. Anti-Flt1 also reduced atherosclerotic plaque growth and vulnerability, but the atheroprotective effect was not attributable to reduced plaque neovascularization. Inhibition of VEGF receptor Flk1 did not affect arthritis or atherosclerosis, indicating that inhibition of Flk1-driven angiogenesis alone was not sufficient to halt disease progression. The anti-inflammatory effects of anti-Flt1 were attributable to reduced mobilization of bone marrow-derived myeloid progenitors into the peripheral blood; impaired infiltration of Flt1-expressing leukocytes in inflamed tissues; and defective activation of myeloid cells. Thus, PlGF and Flt1 constitute potential candidates for therapeutic modulation of angiogenesis and inflammation.