2,081 research outputs found
Classical dendritic cells mediate fibrosis directly via the retinoic acid pathway in severe eye allergy
Fibrosis is a shared end-stage pathway to lung, liver, and heart failure. In the ocular mucosa (conjunctiva), fibrosis leads to blindness in trachoma, pemphigoid, and allergy. The indirect fibrogenic role of DCs via T cell activation and inflammatory cell recruitment is well documented. However, here we demonstrate that DCs can directly induce fibrosis. In the mouse model of allergic eye disease (AED), classical CD11b(+) DCs in the ocular mucosa showed increased activity of aldehyde dehydrogenase (ALDH), the enzyme required for retinoic acid synthesis. In vitro, CD11b(+) DC-derived ALDH was associated with 9-cis-retinoic acid ligation to retinoid x receptor (RXR), which induced conjunctival fibroblast activation. In vivo, stimulating RXR led to rapid onset of ocular mucosal fibrosis, whereas inhibiting ALDH activity in DCs or selectively depleting DCs markedly reduced fibrosis. Collectively, these data reveal a profibrotic ALDH-dependent pathway by DCs and uncover a role for DC retinoid metabolism
Maze solvers demystified and some other thoughts
There is a growing interest towards implementation of maze solving in
spatially-extended physical, chemical and living systems. Several reports of
prototypes attracted great publicity, e.g. maze solving with slime mould and
epithelial cells, maze navigating droplets. We show that most prototypes
utilise one of two phenomena: a shortest path in a maze is a path of the least
resistance for fluid and current flow, and a shortest path is a path of the
steepest gradient of chemoattractants. We discuss that substrates with
so-called maze-solving capabilities simply trace flow currents or chemical
diffusion gradients. We illustrate our thoughts with a model of flow and
experiments with slime mould. The chapter ends with a discussion of experiments
on maze solving with plant roots and leeches which show limitations of the
chemical diffusion maze-solving approach.Comment: This is a preliminary version of the chapter to be published in
Adamatzky A. (Ed.) Shortest path solvers. From software to wetware. Springer,
201
Theoretical growth model space for Cities
This work raises a theoretical model of spatial growth for the cities in which makes explicit that the growth of population and income growth determined the city s expansion in terms of area built for business and the area destined for housing At the same time shows that local public policy can slow down the growth of the population in the cities by avoiding that generate an unbalanced growth and thus increase the housing defici
Harmonizing Minds: Exploring the Interplay of Music and Physics to Enhance Cognitive Processes in Adolescents
Is music related to physics Is there any relationship between music and physics in our brain It is probably not a coincidence that Brian May or Albert Einstein were good at science and music It is well known music provokes the activation of several cytoarchitectural regions of the brain Especially when playing an instrument To learn physics or even thinking about a new experiment in order to prove a scientific hypothesis requires a good base of mathematics and creativity implying intuition well structured knowledge and the ability to develop order from chaos In this article the creative process Wallas stages preparation incubation illumination evaluation of composing a new musical score and physics learning or research are analyzed from a physiological and psychological point of view There are several common structures in composing music and physics research especially the dorsolateral prefrontal cortex as a fundamental area of the executive functions It is possible to consider music and physics as complementary learning tools to improve more general cognitive processes And we can find applications in education These processes contribute to students cognitive development critical thinking skills and emotional engagement to musi
Approximating Mexican highways with slime mould
Plasmodium of Physarum polycephalum is a single cell visible by unaided eye.
During its foraging behavior the cell spans spatially distributed sources of
nutrients with a protoplasmic network. Geometrical structure of the
protoplasmic networks allows the plasmodium to optimize transport of nutrients
between remote parts of its body. Assuming major Mexican cities are sources of
nutrients how much structure of Physarum protoplasmic network correspond to
structure of Mexican Federal highway network? To find an answer undertook a
series of laboratory experiments with living Physarum polycephalum. We
represent geographical locations of major cities by oat flakes, place a piece
of plasmodium in Mexico city area, record the plasmodium's foraging behavior
and extract topology of nutrient transport networks. Results of our experiments
show that the protoplasmic network formed by Physarum is isomorphic, subject to
limitations imposed, to a network of principle highways. Ideas and results of
the paper may contribute towards future developments in bio-inspired road
planning
Two-dimensional Vortices in Superconductors
Superconductors have two key characteristics. They expel magnetic field and
they conduct electrical current with zero resistance. However, both properties
are compromised in high magnetic fields which can penetrate the material and
create a mixed state of quantized vortices. The vortices move in response to an
electrical current dissipating energy which destroys the zero resistance
state\cite{And64}. One of the central problems for applications of high
temperature superconductivity is the stabilization of vortices to ensure zero
electrical resistance. We find that vortices in the anisotropic superconductor
BiSrCaCuO (Bi-2212) have a phase transition from
a liquid state, which is inherently unstable, to a two-dimensional vortex
solid. We show that at high field the transition temperature is independent of
magnetic field, as was predicted theoretically for the melting of an ideal
two-dimensional vortex lattice\cite{Fis80,Gla91}. Our results indicate that the
stable solid phase can be reached at any field as may be necessary for
applications involving superconducting magnets\cite{Has04,Sca04,COHMAG}. The
vortex solid is disordered, as suggested by previous studies at lower
fields\cite{Lee93,Cub93}. But its evolution with increasing magnetic field
displays unexpected threshold behavior that needs further investigation.Comment: 5 pages and 4 figures. submitted to Nature Physic
Quantitative principles of cis-translational control by general mRNA sequence features in eukaryotes.
BackgroundGeneral translational cis-elements are present in the mRNAs of all genes and affect the recruitment, assembly, and progress of preinitiation complexes and the ribosome under many physiological states. These elements include mRNA folding, upstream open reading frames, specific nucleotides flanking the initiating AUG codon, protein coding sequence length, and codon usage. The quantitative contributions of these sequence features and how and why they coordinate to control translation rates are not well understood.ResultsHere, we show that these sequence features specify 42-81% of the variance in translation rates in Saccharomyces cerevisiae, Schizosaccharomyces pombe, Arabidopsis thaliana, Mus musculus, and Homo sapiens. We establish that control by RNA secondary structure is chiefly mediated by highly folded 25-60 nucleotide segments within mRNA 5' regions, that changes in tri-nucleotide frequencies between highly and poorly translated 5' regions are correlated between all species, and that control by distinct biochemical processes is extensively correlated as is regulation by a single process acting in different parts of the same mRNA.ConclusionsOur work shows that general features control a much larger fraction of the variance in translation rates than previously realized. We provide a more detailed and accurate understanding of the aspects of RNA structure that directs translation in diverse eukaryotes. In addition, we note that the strongly correlated regulation between and within cis-control features will cause more even densities of translational complexes along each mRNA and therefore more efficient use of the translation machinery by the cell
The Economic Impact of Women is Greater than that of Men: Analysis of the Secondary Sector with the Input-Output Tables
The present study hopes to clarify the participation of women s work in secondary sector activities which include those in manufacturing mining and quarrying energy subsector and construction transcending in turn to the measurement of the economic impact or effect in the rest of the sectors in Panam
Activation of the innate immune receptor Dectin-1 upon formation of a 'phagocytic synapse'.
Innate immune cells must be able to distinguish between direct binding to microbes and detection of components shed from the surface of microbes located at a distance. Dectin-1 (also known as CLEC7A) is a pattern-recognition receptor expressed by myeloid phagocytes (macrophages, dendritic cells and neutrophils) that detects β-glucans in fungal cell walls and triggers direct cellular antimicrobial activity, including phagocytosis and production of reactive oxygen species (ROS). In contrast to inflammatory responses stimulated upon detection of soluble ligands by other pattern-recognition receptors, such as Toll-like receptors (TLRs), these responses are only useful when a cell comes into direct contact with a microbe and must not be spuriously activated by soluble stimuli. In this study we show that, despite its ability to bind both soluble and particulate β-glucan polymers, Dectin-1 signalling is only activated by particulate β-glucans, which cluster the receptor in synapse-like structures from which regulatory tyrosine phosphatases CD45 and CD148 (also known as PTPRC and PTPRJ, respectively) are excluded (Supplementary Fig. 1). The 'phagocytic synapse' now provides a model mechanism by which innate immune receptors can distinguish direct microbial contact from detection of microbes at a distance, thereby initiating direct cellular antimicrobial responses only when they are required
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