Orbital ordering phenomena in dd- and ff-electron systems

In recent decades, novel magnetism of $d$- and $f$-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 $d$- and $f$-electron compounds has been separately investigated rather in different manners. One of common features of both $d$- and $f$-electron systems is certainly the existence of active orbital degree of freedom, but in $f$-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 $d$-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 $d$- and $f$-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 $d$- and $f$-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 Controls Constitutive Freezing Tolerance in Arabidopsis by Attenuating the Levels of Osmoprotectants, Stress-Related Hormones and Anthocyanins

[EN] Plant tolerance to freezing temperatures is governed by endogenous constitutive components and environmental inducing factors. Nitric oxide (NO) is one of the endogenous components that participate in freezing tolerance regulation. A combined metabolomic and transcriptomic characterization of NO-deficient nia1,2noa1¿2 mutant plants suggests that NO acts attenuating the production and accumulation of osmoprotective and regulatory metabolites, such as sugars and polyamines, stress-related hormones, such as ABA and jasmonates, and antioxidants, such as anthocyanins and flavonoids. Accordingly, NO-deficient plants are constitutively more freezing tolerant than wild type plants.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 Janice Jones and Danny Alexander (Metabolon Inc., USA) on metabolomic analyses.Costa-Broseta, Á.; Perea-Resa, C.; Castillo López Del Toro, MC.; Ruíz, MF.; Salinas, J.; Leon Ramos, J. (2018). Nitric Oxide Controls Constitutive Freezing Tolerance in Arabidopsis by Attenuating the Levels of Osmoprotectants, Stress-Related Hormones and Anthocyanins. Scientific Reports. 8. https://doi.org/10.1038/s41598-018-27668-8S8Janská, A., Marsík, P., Zelenková, S. & Ovesná, J. Cold stress and acclimation - what is important for metabolic adjustment? Plant Biol (Stuttg) 12, 395–405 (2010).Eremina, M., Rozhon, W. & Poppenberger, B. Hormonal control of cold stress responses in plants. Cell Mol Life Sci 73, 797–810 (2016).Winkel-Shirley, B. Biosynthesis of flavonoids and effects of stress. Curr Opin Plant Biol 5, 218–223 (2002).Cuevas, J. C. et al. 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Antioxidant Systems are Regulated by Nitric Oxide-Mediated Post-translational Modifications (NO-PTMs). Front. Plant Sci. 7, 152 (2016).Castillo, M. C. & León, J. Expression of the beta-oxidation gene 3-ketoacyl-CoA thiolase 2 (KAT2) is required for the timely onset of natural and dark-induced leaf senescence in Arabidopsis. J. Exp. Bot. 59, 2171–2179 (2008).Guo, F. Q., Okamoto, M. & Crawford, N. M. Identification of a plant nitric oxide synthase gene involved in hormonal signaling. Science 302, 100–103 (2003).Solfanelli, C., Poggi, A., Loreti, E., Alpi, A. & Perata, P. Sucrose-specific induction of the anthocyanin biosynthetic pathway in Arabidopsis. Plant Physiol. 140, 637–646 (2006).Seo, M., Jikumaru, Y. & Kamiya, Y. Profiling of Hormones and Related Metabolites in Seed Dormancy and Germination Studies. Meth. Mol. Biol. 773, 99–111 (2011)

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&#8201;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&#8201;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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Rubella seromarkers and determinants of infection among tanzanian children and adolescents in prevaccination Era: Are we in the right track?

Background: The World health organization advocates assessment of the burden of rubella and congenital rubella syndrome (CRS) by seroepidemiological surveys and surveillance programs in all countries without vaccination programs. Due to scarcity of data in developing countries, this study was conducted to assess the seromakers for natural rubella infection in Tanzania during prevaccination era so as to ascertain the gaps for future research and prevention strategies. Methods: A cross-sectional study was conducted between September and October 2014. Indirect enzyme-linked immunosorbent assay was used to detect rubella IgG and IgM antibodies. STATA version 11 was used to perform data analysis. Results: Of 723 enrolled participants, 368 (50.8%) and 94 (13%) were positive for specific IgG and IgM rubella antibodies, respectively. On multivariable logistic regression analysis, significant determinants of rubella IgG seropositivity were increase in age (odds ratios [OR]: 1.24, 95% confidence interval [CI]: 1.18-1.29, P < 0.001), low socioeconomic status (SES) (OR: 2.38, 95% CI: 1.1.23-4.50, P = 0.010), and absence of rash (OR: 4.34, 95% CI: 1.1.17-15.3, P = 0.027), while only the presence of rashes was significant determinant of rubella IgM seropositivity (OR: 2.5, 95%; 1.07-5.98, P = 0.034). Significantly higher mean IgG titers were observed in population ≥10 years (P < 0.001), those residing in urban and peri-urban areas (P < 0.001), those from employed mothers (P = 0.018), and those with no current history of fever (P = 0.018). Conclusions: The prevalence of specific rubella IgG antibodies in Tanzania is high and is associated with increase in age, absence of rash, and low SES. Results suggest a need to reconsider upper age limit for vaccination campaigns in developing countries. Screening and vaccinating women may be cost-effective campaign to prevent CRS in developing countries

A new biased estimator based on ridge estimation

Biased regression, Mean squared error, Multicollinearity, Ridge regression, Liu estimator,