85 research outputs found
Borreria (Rubiaceae) from Paraguay: occurrences, richness, geographical distribution, and nomenclatural novelties
Borreria is a genus into the Spermacoce clade with ca 80 native species in the Americas, from southem EE.UU. to center of Argentina. In South America, taxonomic and floristic contributions were performed in the genus to Bolivian, Brazilian, and Argentinian floras. In this context, nomenclatural changes, new records, and new species have been published in the last decades for Paraguay, but until now there is no comprehensive taxonomic treatment. In addition, this country has a great diversity of ecoregions as the Atlantic Forest, Cerrado, âCordillera de los Altosâ, Dry and Humid Chaco, Pantanal, and âSabanas MesopotĂĄmicasâ. Our goal is to present an overview of Borreria in Paraguay, its geographical distribution, and the association of its occurrences in diĂferent ecoregions. We studied collections deposited in BM, CTES, F, FACEN, FCQ, G, HUEFS, MO, P, SI, and SP. Coordinates were taken from the labels on each specimen, and when these were absent, the point was georeferenced using Google Earth according the locality ñames. A total of 503 datapoints were obtained corresponding to 21 species of Borreria. Each occurrence and ecoregions were mapped using QGIS. A map o f known richness was generated with this information and was quantified with 5 x 5 km cells using the Biodiverse software. As result, B. verticillata is the widest distribution species, whereas B. viridiflora is the only endemic species for Paraguay. Besides that, the ecoregion with the higher richness is the Atlantic Forest since it has 20 species, with B. diacrodonta, B. remota, and/i. runkii exclusive for it. In contrast, Pantanal and Dry Chaco have only one species each, B. cupularis and B. spinosa, respectively. Borreria alata is registered as a new record for the country, lectotypes for three varietal ñames are chosen, and five new synonyms for B. argĂ©ntea, B. orinocensis, and B. verticillata are proposed
There and back again: molecular phylogenetics of the Brazilian endemic Psyllocarpus (Rubiaceae: Spermacoceae) supports a circumscription of the genus based on its original concept
The Spermacoce clade (tribe Spermacoceae) is one of the most taxonomically complex groups in Rubiaceae due to the unclear delimitation of Borreria and Spermacoce, in which several smaller genera are phylogenetically intermingled. One of these genera is the Brazilian endemic Psyllocarpus, whose circumscription was broadened, thereby including two sections. Psyllocarpus sect. Psyllocarpus, being based on the original genus delineation, includes nine species, distributed in the Cerrado and campo rupestre of eastern Brazil, whereas P. sect. Amazonica comprises three species, occurring in the Amazonian campinas. Furthermore, P. intermedius was not classified in any of these sections when it was later described. In order to test the monophyly of Psyllocarpus and assess its relationships to other genera, we conducted phylogenetic analyses, sampling across the whole Spermacoce clade, including nearly all Psyllocarpus species. A combined nuclear ribosomal (ETS and ITS) and plastid (rps16 and trnLtrnF) dataset was generated, representing 124 species (ca 25% of the species in the clade) in 15 genera (ca 65%). Various methodologies were applied to investigate the degree of incongruence among markers and address the lack of resolution and low support values for some branches. Our results revealed that Psyllocarpus is not monophyletic. Psyllocarpus campinorum (from P . sect. Amazonica) and P intermedius are situated as distinct lineages in the Spermacoce clade, yet do not belong to Psyllocarpus. Members of section Psyllocarpus form a strongly supported clade sister to Staelia and was recovered with high to maximum support across different datasets and inference methods. Therefore, Psyllocarpus has to be circumscribed based on its original concept, excluding P. sect. Amazonica and P. intermedius. This establishes the genus as a monophyletic and easily diagnosable taxon, characterized by terete leaves, homostylous flowers, a bilobate calyx, included stamens and style, and compressed, septifragally dehiscent capsules with a persistent septum
Genome-wide study of association and interaction with maternal cytomegalovirus infection suggests new schizophrenia loci.
Genetic and environmental components as well as their interaction contribute to the risk of schizophrenia, making it highly relevant to include environmental factors in genetic studies of schizophrenia. This study comprises genome-wide association (GWA) and follow-up analyses of all individuals born in Denmark since 1981 and diagnosed with schizophrenia as well as controls from the same birth cohort. Furthermore, we present the first genome-wide interaction survey of single nucleotide polymorphisms (SNPs) and maternal cytomegalovirus (CMV) infection. The GWA analysis included 888 cases and 882 controls, and the follow-up investigation of the top GWA results was performed in independent Danish (1396 cases and 1803 controls) and German-Dutch (1169 cases, 3714 controls) samples. The SNPs most strongly associated in the single-marker analysis of the combined Danish samples were rs4757144 in ARNTL (P=3.78 Ă 10(-6)) and rs8057927 in CDH13 (P=1.39 Ă 10(-5)). Both genes have previously been linked to schizophrenia or other psychiatric disorders. The strongest associated SNP in the combined analysis, including Danish and German-Dutch samples, was rs12922317 in RUNDC2A (P=9.04 Ă 10(-7)). A region-based analysis summarizing independent signals in segments of 100âkb identified a new region-based genome-wide significant locus overlapping the gene ZEB1 (P=7.0 Ă 10(-7)). This signal was replicated in the follow-up analysis (P=2.3 Ă 10(-2)). Significant interaction with maternal CMV infection was found for rs7902091 (P(SNP Ă CMV)=7.3 Ă 10(-7)) in CTNNA3, a gene not previously implicated in schizophrenia, stressing the importance of including environmental factors in genetic studies
Requirement of Podocalyxin in TGF-Beta Induced Epithelial Mesenchymal Transition
Epithelial mesenchymal transition (EMT) is characterized by the development of mesenchymal properties such as a fibroblast-like morphology with altered cytoskeletal organization and enhanced migratory potential. We report that the expression of podocalyxin (PODXL), a member of the CD34 family, is markedly increased during TGF-ÎČ induced EMT. PODXL is enriched on the leading edges of migrating A549 cells. Silencing of podocalyxin expression reduced cell ruffle formation, spreading, migration and affected the expression patterns of several proteins that normally change during EMT (e.g., vimentin, E-cadherin). Cytoskeletion assembly in EMT was also found to be dependent on the production of podocalyin. Compositional analysis of podocalyxin containing immunoprecipitates revealed that collagen type 1 was consistently associated with these isolates. Collagen type 1 was also found to co-localize with podocalyxin on the leading edges of migrating cells. The interactions with collagen may be a critical aspect of podocalyxin function. Podocalyxin is an important regulator of the EMT like process as it regulates the loss of epithelial features and the acquisition of a motile phenotype
Broad-band high-resolution rotational spectroscopy for laboratory astrophysics
We present a new experimental set-up devoted to the study of gas phase molecules and processes using broad-band high spectral resolution rotational spectroscopy. A reactor chamber is equipped with radio receivers similar to those used by radio astronomers to search for molecular emission in space. The whole range of the Q (31.5-50 GHz) and W bands (72-116.5 GHz) is available for rotational spectroscopy observations. The receivers are equipped with 16 Ă 2.5 GHz fast Fourier transform spectrometers with a spectral resolution of 38.14 kHz allowing the simultaneous observation of the complete Q band and one-third of the W band. The whole W band can be observed in three settings in which the Q band is always observed. Species such as CH3CN, OCS, and SO2 are detected, together with many of their isotopologues and vibrationally excited states, in very short observing times. The system permits automatic overnight observations, and integration times as long as 2.4 Ă 105 s have been reached. The chamber is equipped with a radiofrequency source to produce cold plasmas, and with four ultraviolet lamps to study photochemical processes. Plasmas of CH4, N2, CH3CN, NH3, O2, and H2, among other species, have been generated and the molecular products easily identified by the rotational spectrum, and via mass spectrometry and optical spectroscopy. Finally, the rotational spectrum of the lowest energy conformer of CH3CH2NHCHO (N-ethylformamide), a molecule previously characterized in microwave rotational spectroscopy, has been measured up to 116.5 GHz, allowing the accurate determination of its rotational and distortion constants and its search in space.We thank the European Research Council for funding support under Synergy Grant ERC-2013-SyG, G.A. 610256 (NANOCOSMOS). IT, VJH, and JLD acknowledge additional partial support from the Spanish State Research Agency (AEI) through grant FIS2016-77726-C3-1-P. JAMG, LM, and GS acknowledge additional partial support from the Spanish State Research Agency (AEI) through grant MAT2017-85089-C2-1R. We thank David LĂłpez Romero for his help during the process of installation, commissioning, and cleaning of the chamber. We would like to thank Kremena Makasheva for the useful comments and suggestions during the experiments with Hexamethyldisiloxane. We would also like to thank Rosa LebrĂłn, JesĂșs Quintanilla, and Cristina Soria for providing us with the sample of N-ethylformamide. Sandra I. RamĂrez acknowledges support from the FONCICYT under grant number 291842. Celina BermĂșdez thanks the Spanish Ministerio de Ciencia InnovaciĂłn y Universidades for the Juan de la Cierva grant FJCI-2016-27983
Cross-tolerance to abiotic stresses in halophytes: Application for phytoremediation of organic pollutants
International audienceHalopytes are plants able to tolerate high salt concentrations but no clear definition was retained for them. In literature, there are more studies that showed salt-enhanced tolerance to other abiotic stresses compared to investigations that found enhanced salt tolerance by other abiotic stresses in halophytes. The phenomenon by which a plant resistance to a stress induces resistance to another is referred to as cross-tolerance. In this work, we reviewed cross-tolerance in halophytes at the physiological, biochemical, and molecular levels. A special attention was accorded to the cross-tolerance between salinity and organic pollutants that could allow halophytes a higher potential of xenobiotic phytoremediation in comparison with glycophytes
Aquatic food webs in mangrove and seagrass habitats of Centla Wetland, a Biosphere Reserve in Southeastern Mexico
AI is a viable alternative to high throughput screening: a 318-target study
: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNetÂź convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNetÂź model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery
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