High toxicity and specificity of the saponin 3-GlcA-28-AraRhaxyl-medicagenate, from Medicago truncatula seeds, for Sitophilus oryzae

<p>Abstract</p> <p>Background</p> <p>Because of the increasingly concern of consumers and public policy about problems for environment and for public health due to chemical pesticides, the search for molecules more safe is currently of great importance. Particularly, plants are able to fight the pathogens as insects, bacteria or fungi; so that plants could represent a valuable source of new molecules.</p> <p>Results</p> <p>It was observed that <it>Medicago truncatul</it>a seed flour displayed a strong toxic activity towards the adults of the rice weevil <it>Sitophilus oryzae</it> (Coleoptera), a major pest of stored cereals. The molecule responsible for toxicity was purified, by solvent extraction and HPLC, and identified as a saponin, namely 3-GlcA-28-AraRhaxyl-medicagenate. Saponins are detergents, and the CMC of this molecule was found to be 0.65 mg per mL. Neither the worm <it>Caenorhabditis elegans</it> nor the bacteria <it>E. coli</it> were found to be sensitive to this saponin, but growth of the yeast <it>Saccharomyces cerevisiae</it> was inhibited at concentrations higher than 100 μg per mL. The purified molecule is toxic for the adults of the rice weevils at concentrations down to 100 μg per g of food, but this does not apply to the others insects tested, including the coleopteran <it>Tribolium castaneum</it> and the Sf9 insect cultured cells.</p> <p>Conclusions</p> <p>This specificity for the weevil led us to investigate this saponin potential for pest control and to propose the hypothesis that this saponin has a specific mode of action, rather than acting <it>via</it> its non-specific detergent properties.</p

Modelling semantic transparency

We present models of semantic transparency in which the perceived trans- parency of English noun–noun compounds, and of their constituent words, is pre- dicted on the basis of the expectedness of their semantic structure. We show that such compounds are perceived as more transparent when the first noun is more frequent, hence more expected, in the language generally; when the compound semantic rela- tion is more frequent, hence more expected, in association with the first noun; and when the second noun is more productive, hence more expected, as the second ele- ment of a noun–noun compound. Taken together, our models of compound and con- stituent transparency lead us to two conclusions. Firstly, although compound trans- parency is a function of the transparencies of the constituents, the two constituents differ in the nature of their contribution. Secondly, since all the significant predictors in our models of compound transparency are also known predictors of processing speed, perceived transparency may itself be a reflex of ease of processing

The Catalogue for Astrophysical Turbulence Simulations (CATS)

Turbulence is a key process in many fields of astrophysics. Advances in numerical simulations of fluids over the last several decades have revolutionized our understanding of turbulence and related processes such as star formation and cosmic ray propagation. However, data from numerical simulations of astrophysical turbulence are often not made public. We introduce a new simulation-oriented database for the astronomical community: the Catalogue for Astrophysical Turbulence Simulations (CATS), located at www.mhdturbulence.com. CATS includes magnetohydrodynamic (MHD) turbulent box simulation data products generated by the public codes athena++, arepo, enzo, and flash. CATS also includes several synthetic observational data sets, such as turbulent HI data cubes. We also include measured power spectra and three-point correlation functions from some of these data. We discuss the importance of open-source statistical and visualization tools for the analysis of turbulence simulations such as those found in CATS.D.C. acknowledges compute resources provided by NSF TRAC allocations TG-AST090110, TG-MCA07S014, and TG-AST140008. C.F. acknowledges funding provided by the Australian Research Council (Discovery Project DP170100603 and Future Fellowship FT180100495), the Australia-Germany Joint Research Cooperation Scheme (UA-DAAD), and high-performance computing resources provided by the Leibniz Rechenzentrum, the Gauss Centre for Supercomputing (grants pr32lo), and the Australian National Computational Infrastructure (grant ek9) in the framework of the National Computational Merit Allocation Scheme and the ANU Merit Allocation Scheme.and from the National Computational Infrastructure (NCI), which is supported by the Australian Government (award jh2). A.L. acknowledges the support of the NSF AST 1816234, NASA TCAN 144AAG1967, NASA ATP AAH7546 and the Flatiron Institute. J.C.'s work is supported by the National R&D Program through the National Research Foundation of Korea Grants funded by the Korean Government (NRF2016R1A5A1013277 and NRF-2016R1D1A1B02015014). P.M. acknowledges support for this work provided by NASA through Einstein Postdoctoral Fellowship grant number PF7-180164 awarded by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-0306

The Physics of Star Cluster Formation and Evolution

© 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00689-4.Star clusters form in dense, hierarchically collapsing gas clouds. Bulk kinetic energy is transformed to turbulence with stars forming from cores fed by filaments. In the most compact regions, stellar feedback is least effective in removing the gas and stars may form very efficiently. These are also the regions where, in high-mass clusters, ejecta from some kind of high-mass stars are effectively captured during the formation phase of some of the low mass stars and effectively channeled into the latter to form multiple populations. Star formation epochs in star clusters are generally set by gas flows that determine the abundance of gas in the cluster. We argue that there is likely only one star formation epoch after which clusters remain essentially clear of gas by cluster winds. Collisional dynamics is important in this phase leading to core collapse, expansion and eventual dispersion of every cluster. We review recent developments in the field with a focus on theoretical work.Peer reviewe

Continental Arc Plutonism in a Juvenile Crust: The Neoproterozoic Metagabbro-Diorite Complexes of Sinai, Northern Arabian-Nubian Shield

Based on new field, petrographic, and whole-rock geochemistry data, we investigated three discrete metagabbro-diorite complexes (MGDC) across the E-W Sinai to contribute to increasing knowledge of the evolution of the juvenile continental crust of the Neoproterozoic Arabian–Nubian Shield. The three MGDCs vary in the dominance of the gabbroic versus dioritic rock types among each of them. Gabbroids are distinguished into pyroxene-hornblende gabbros and hornblende gabbros, whereas dioritic rocks have been subdivided into diorites and quartz diorites. The studied MGDC rocks are almost metaluminous and possess prevalent calc-alkaline characteristics over subsidiary tholeiitic and alkaline affinities. The most distinctive feature in the profiles of the investigated MGDCs on the N-MORB-normalized spider diagrams is the coincidence of stout negative Nb anomalies and projecting positive Pb spikes, which is typical of igneous rocks evolved in subduction zones. The three MGDC samples exhibit variably LREE-enriched patterns [(La/Yb)N = 4.92–18.55; av. = 9.04], either lacking or possessing weak to negligible positive and negative Eu anomalies. The calculated apatite and zircon crystallization temperatures reveal the earlier separation of apatite at higher temperatures, with the obvious possibility of two genetic types of apatite and zircon in the magma (cognate vs. xenocrystic) since both accessories have yielded very wide ranges of crystallization temperatures. The investigated MGDCs were formed in a continental arc setting, particularly a thick-crust arc (>39 km). The parent magmas comprised components derived from the melting of the mantle wedge, subducting oceanic lithosphere, and subducting overlying sediments. The mantle input was from a spinel–garnet transitional mantle source at a depth of ca. 75–90 km. The impact of slab-derived fluids was much greater than that of slab-derived melts, and so subduction-related fluids had a crucial effect on metasomatizing the partially melted mantle source. The parent mantle-derived magma has been subjected to substantial crustal contamination as a dominant mechanism of differentiation

Aktywnosc antygrzybowa saponin korzeni Medicago hybrida w stosunku do kilku patogenow roslin ozdobnych

Antifungal activity of total saponins originated from roots of Medicago hybrida (Pourret) Trautv. were evaluated in vitro against six pathogenic fungi and eight individual major saponin glycosides were tested against one of the most susceptible fungi. The total saponins showed fungitoxic effect at all investigated concentrations (0.01%, 0.05% and 0.1%) but their potency was different for individual fungi. The highest saponin concentration (0.1%) was the most effective and the inhibition of Fusarium oxysporum f. sp. callistephi, Botrytis cinerea, Botrytis tulipae, Phoma narcissi, Fusarium oxysporum f. sp. narcissi was 84.4%, 69.9%, 68.6%, 57.2%, 55.0%, respectively. While Fusarium oxysporum Schlecht., a pathogen of Muscari armeniacum, was inhibited by 9.5% only. Eight major saponin glycosides isolated from the total saponins of M. hybrida roots were tested against the mycelium growth of Botrytis tulipae. The mycelium growth of the pathogen was greatly inhibited by hederagenin 3-O-β -D-glucopyranoside and medicagenic acid 3-O-β -D-glucopyranoside. Medicagenic acid 3-O-β -D-glucuronopyranosyl-28-O-β -D-glucopyranoside and oleanolic acid 3-O-[β -D-glucuronopyranosyl(1→2)-α -L-galactopyranosyl]-28-O-β -D-glucopyranoside showed low fungitoxic activity. Medicagenic acid 3-O-β-D-glucopyranosyl- 28-O-β -D-glucopyranoside, hederagenin 3-O-[α -L-rhamnopyranosyl(1→-2)-D-glucopyranosyl( 1→2)-D-glucopyranosyl]- 28-O-β -D-glucopyranoside and hederagenin 3-O-α -D-glucuronopyranosyl-28-O-β -D-glucopyranoside did not limit or only slightly inhibited growth of the tested pathogen. While 2β, 3β-dihydroxyolean-12 ene-23-al-28-oic acid 3-O-β -D-glucuronopyranosyl-28-O-β -D-glucopyranoside slightly stimulated mycelium growth of B. tulipae.Oszacowano in vitro aktywnooeć sumy saponin pozyskanych z korzeni Medicago hybrida na wzrost grzybni szeoeciu patogenów i przetestowano osiem dominują- cych glikozydów saponinowych względem Botrytis cinerea. Suma saponin wykazała fungistatyczny wpływ przy wszystkich badanych stężeniach (0,01%, 0,05% i 0,1%) ale ich aktywnooeć była różna dla poszczególnych grzybów. Najwyższe stężenie (0.1%) saponin było najbardziej efektywne i wyrażało się silnym hamowaniem Fusarium oxysporum f. sp. callistephi (84,4%), Botrytis cinerea (69,9%), Botrytis tulipae (68,6%), Phoma narcissi (57,2%), Fusarium oxysporum f. sp. narcissi (55,0%). Podczas, gdy Fusarium oxysporum Schlecht, patogen pochodzący z Muscari armeniacum był zahamowany zaledwie w 9,5%. Osiem dominujących glikozydów saponinowych wyodrębnionych z sumy saponin testowano w stosunku do Botrytis tulipae. Wzrost liniowy grzybni tego patogena był silnie zahamowany przez dwa glikozydy: 3-O-β-Dglukopyranozyd hederageniny i 3-O-β -D-glukopyranozyd kwasu medikagenowego. 3-O-β-D-glukuronopyranozylo-28-O-β-D-glukopyranozyd kwasu medikagenowego i 3-O-[-D-glukuronopyranozylo(1→2)- α -L-galaktopyranozylo]-28-O-β -D-glukopyranozyd kwasu oleanolowego wykazywały niską fungitoksycznooeć. 3-O-β -D-glukopyranozylo- 28-O-β -D-glukopyranozyd kwasu medikagenowego, 3-O-[α-L-rhamnopyranozylo( 1→2)-β -D-glukopyranozylo(1→2)-D-glukopyranozylo]-28-O-β-Dglukopyranozyd hederageniny i 3-O-β -D-glukuronopyranozylo- 28-O-β -D-glukopyranozyd hederageniny nie wpływają lub tylko oeladowo wpływają na wzrost badanego patogena. Podczas, gdy 2β,3β-dihydroxyolean-12ene-23-al-28-karboksy 3-O-β -D-glukuronopyranozylo-28-O-β-D-glukopyranozyd lekko stymuluje wzrost B. tulipae