30 research outputs found
Orbital ordering phenomena in - and -electron systems
In recent decades, novel magnetism of - and -electron compounds has
been discussed very intensively both in experimental and theoretical research
fields of condensed matter physics. It has been recognized that those material
groups are in the same category of strongly correlated electron systems, while
the low-energy physics of - and -electron compounds has been separately
investigated rather in different manners. One of common features of both -
and -electron systems is certainly the existence of active orbital degree of
freedom, but in -electron materials, due to the strong spin-orbit
interaction in rare-earth and actinide ions, the physics seems to be quite
different from that of -electron systems. In general, when the number of
internal degrees of freedom and relevant interactions is increased, it is
possible to obtain rich phase diagram including large varieties of magnetic
phases by using several kinds of theoretical techniques. However, we should not
be simply satisfied with the reproduction of rich phase diagram. It is believed
that more essential point is to seek for a simple principle penetrating
complicated phenomena in common with - and -electron materials, which
opens the door to a new stage in orbital physics. In this sense, it is
considered to be an important task of this article to explain common features
of magnetism in - and -electron systems from a microscopic viewpoint,
using a key concept of orbital ordering, in addition to the review of the
complex phase diagram of each material group.Comment: 112 pages, 38 figure
Species Delimitation in Taxonomically Difficult Fungi: The Case of Hymenogaster
False truffles are ecologically important as mycorrhizal partners of trees and evolutionarily highly interesting as the result of a shift from epigeous mushroom-like to underground fruiting bodies. Since its first description by Vittadini in 1831, inappropriate species concepts in the highly diverse false truffle genus Hymenogaster has led to continued confusion, caused by a large variety of prevailing taxonomical opinions.In this study, we reconsidered the species delimitations in Hymenogaster based on a comprehensive collection of Central European taxa comprising more than 140 fruiting bodies from 20 years of field work. The ITS rDNA sequence dataset was subjected to phylogenetic analysis as well as clustering optimization using OPTSIL software.Among distinct species concepts from the literature used to create reference partitions for clustering optimization, the broadest concept resulted in the highest agreement with the ITS data. Our results indicate a highly variable morphology of H. citrinus and H. griseus, most likely linked to environmental influences on the phenology (maturity, habitat, soil type and growing season). In particular, taxa described in the 19(th) century frequently appear as conspecific. Conversely, H. niveus appears as species complex comprising seven cryptic species with almost identical macro- and micromorphology. H. intermedius and H. huthii are described as novel species, each of which with a distinct morphology intermediate between two species complexes. A revised taxonomy for one of the most taxonomically difficult genera of Basidiomycetes is proposed, including an updated identification key. The (semi-)automated selection among species concepts used here is of importance for the revision of taxonomically problematic organism groups in general
Gut mucosal DAMPs in IBD: From mechanisms to therapeutic implications
Endogenous damage-associated molecular patterns (DAMPs) are released during tissue damage and have increasingly recognized roles in the etiology of many human diseases. The inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn’s disease (CD), are immune-mediated conditions where high levels of DAMPs are observed. DAMPs such as calprotectin (S100A8/9) have an established clinical role as a biomarker in IBD. In this review, we use IBD as an archetypal common chronic inflammatory disease to focus on the conceptual and evidential importance of DAMPs in pathogenesis and why DAMPs represent an entirely new class of targets for clinical translation. </p
Nitric oxide triggers a transient metabolic reprogramming in Arabidopsis
[EN] Nitric oxide (NO) regulates plant growth and development as well as responses to stress that enhanced its endogenous production. Arabidopsis plants exposed to a pulse of exogenous NO gas were used for untargeted global metabolomic analyses thus allowing the identification of metabolic processes affected by NO. At early time points after treatment, NO scavenged superoxide anion and induced the nitration and the S-nitrosylation of proteins. These events preceded an extensive though transient metabolic reprogramming at 6 h after NO treatment, which included enhanced levels of polyamines, lipid catabolism and accumulation of phospholipids, chlorophyll breakdown, protein and nucleic acid turnover and increased content of sugars. Accordingly, lipid-related structures such as root cell membranes and leaf cuticle altered their permeability upon NO treatment. Besides, NO-treated plants displayed degradation of starch granules, which is consistent with the increased sugar content observed in the metabolomic survey. The metabolic profile was restored to baseline levels at 24 h post-treatment, thus pointing up the plasticity of plant metabolism in response to nitroxidative stress conditions.This work was supported by grants BIO2011-27526 and BIO2014-56067-P from the Spanish Ministry of Economy and Competitiveness and FEDER funds. We thank support and comments from Danny Alexander (Metabolon Inc., USA) on metabolomic analyses.Leon Ramos, J.; Costa-Broseta, Á.; Castillo López Del Toro, MC. (2016). Nitric oxide triggers a transient metabolic reprogramming in Arabidopsis. Scientific Reports. 6:1-14. doi:10.1038/srep37945S1146Arc, E., Galland, M., Godin, B., Cueff, G. & Rajjou, L. Nitric oxide implication in the control of seed dormancy and germination. Front. Plant Sci. 4, 346 (2013).Beligni, M. V. & Lamattina, L. 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A Soft-Particle Model for Simulations of Diblock Copolymers in Bulk and in Confinement
AbstractWe will present Monte Carlo simulations of a soft-quadrumer model for diblock copolymer melts where each bead of the quadrumer has a size of the order of the gyration radius of half of a block. We will show that such a model captures the micro phase separation of diblock copolymers in the bulk as well as in confinement. For the confined system the form and strength of the interaction between the soft particles representing the diblock copolymers and the wall confining the melt are determined by iterative Boltzmann inversion techniques applied to chemically realistic Molecular Dynamics simulations