24,373 research outputs found
Graphic Thinking and Digital Processes: Three Built Case Studies of Digital Materiality
Think strategic link between computer programming; digital modeling; the data; matter and CNC manufacturing in the various stages of the architectural project is key to update our discipline with new technologies. Our proposal to articulate and digital graphic thought processes; developable folded geometries and compositions is rooted in an expanded graphic thinking through multiple conceptual tools that are already part of the operational structure of our discipline
Capturing the essence of folding and functions of biomolecules using Coarse-Grained Models
The distances over which biological molecules and their complexes can
function range from a few nanometres, in the case of folded structures, to
millimetres, for example during chromosome organization. Describing phenomena
that cover such diverse length, and also time scales, requires models that
capture the underlying physics for the particular length scale of interest.
Theoretical ideas, in particular, concepts from polymer physics, have guided
the development of coarse-grained models to study folding of DNA, RNA, and
proteins. More recently, such models and their variants have been applied to
the functions of biological nanomachines. Simulations using coarse-grained
models are now poised to address a wide range of problems in biology.Comment: 37 pages, 8 figure
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miRNA contributions to pediatric-onset multiple sclerosis inferred from GWAS.
ObjectiveOnset of multiple sclerosis (MS) occurs in childhood for approximately 5% of cases (pediatric MS, or ped-MS). Epigenetic influences are strongly implicated in MS pathogenesis in adults, including the contribution from microRNAs (miRNAs), small noncoding RNAs that affect gene expression by binding target gene mRNAs. Few studies have specifically examined miRNAs in ped-MS, but individuals developing MS at an early age may carry a relatively high burden of genetic risk factors, and miRNA dysregulation may therefore play a larger role in the development of ped-MS than in adult-onset MS. This study aimed to look for evidence of miRNA involvement in ped-MS pathogenesis.MethodsGWAS results from 486 ped-MS cases and 1362 controls from the U.S. Pediatric MS Network and Kaiser Permanente Northern California membership were investigated for miRNA-specific signals. First, enrichment of miRNA-target gene network signals was evaluated using MIGWAS software. Second, SNPs in miRNA genes and in target gene binding sites (miR-SNPs) were tested for association with ped-MS, and pathway analysis was performed on associated target genes.ResultsMIGWAS analysis showed that miRNA-target gene signals were enriched in GWAS (P = 0.038) and identified 39 candidate biomarker miRNA-target gene pairs, including immune and neuronal signaling genes. The miR-SNP analysis implicated dysregulation of miRNA binding to target genes in five pathways, mainly involved in immune signaling.InterpretationEvidence from GWAS suggests that miRNAs play a role in ped-MS pathogenesis by affecting immune signaling and other pathways. Candidate biomarker miRNA-target gene pairs should be further studied for diagnostic, prognostic, and/or therapeutic utility
Do theoretical physicists care about the protein-folding problem?
The prediction of the biologically active native conformation of a protein is
one of the fundamental challenges of structural biology. This problem remains
yet unsolved mainly due to three factors: the partial knowledge of the
effective free energy function that governs the folding process, the enormous
size of the conformational space of a protein and, finally, the relatively
small differences of energy between conformations, in particular, between the
native one and the ones that make up the unfolded state.
Herein, we recall the importance of taking into account, in a detailed
manner, the many interactions involved in the protein folding problem (such as
steric volume exclusion, Ramachandran forces, hydrogen bonds, weakly polar
interactions, coulombic energy or hydrophobic attraction) and we propose a
strategy to effectively construct a free energy function that, including the
effects of the solvent, could be numerically tractable. It must be pointed out
that, since the internal free energy function that is mainly described does not
include the constraints of the native conformation, it could only help to reach
the 'molten globule' state. We also discuss about the limits and the lacks from
which suffer the simple models that we, physicists, love so much.Comment: 27 pages, 4 figures, LaTeX file, aipproc package. To be published in
the book: "Meeting on Fundamental Physics 'Alberto Galindo'", Alvarez-Estrada
R. F. et al. (Ed.), Madrid: Aula Documental, 200
Man and Machine: Questions of Risk, Trust and Accountability in Today's AI Technology
Artificial Intelligence began as a field probing some of the most fundamental
questions of science - the nature of intelligence and the design of intelligent
artifacts. But it has grown into a discipline that is deeply entwined with
commerce and society. Today's AI technology, such as expert systems and
intelligent assistants, pose some difficult questions of risk, trust and
accountability. In this paper, we present these concerns, examining them in the
context of historical developments that have shaped the nature and direction of
AI research. We also suggest the exploration and further development of two
paradigms, human intelligence-machine cooperation, and a sociological view of
intelligence, which might help address some of these concerns.Comment: Preprin
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