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Актуальность исследования определяется созданием принципиально нового способа синтеза титановых порошков высокой степени чистоты из ильменитовых руд месторождений Вьетнама, содержащих в тяжелой фракции смесь ильменита с рутилом. Это одно из приоритетных направлений комплексного развития месторождений редких и редкоземельных элементов во Вьетнаме. Цель: выбор условий, методов и последовательности проведения технологических операций по обогащению вьетнамских ильменитовых руд и последующей их химической переработки с получением высокочистого титана. Объекты: ильменитовая руда месторождения Ха Тинь (Вьетнам) с высоким содержанием оксидов титана, железа, циркония и низким содержанием кремния, алюминия, редкоземельных элементов, ванадия, а также ильменитовый концентрат, полученный в результате обогащения исходной ильменитовой руды. Методы: в процессе обогащения - электростатическая сепарация, флотация, использование коллекторов, активаторов и депрессоров, добавляемых к флотореагентам; при электролитическом синтезе титана - применение расплава в виде смеси фторидов лития, натрия и калия, обладающих минимальной температурой плавления, с добавкой тетрафторида титана; выбор условий запуска электролизера, катодной плотности тока, силы тока и напряжения для осаждения титана на катоде; исследование оптимальных условий выделения титанового порошка при низких температурах с использованием безводного фтороводорода. Результаты. Показана перспективность использования методов электростатической сепарации и флотации при обогащении вьетнамских ильменитовых руд месторождения Ха Тинь. Получен ильменитовый концентрат с содержанием диоксида титана более 50 %. Обоснованы преимущества использования метода прямого фторирования ильменитового концентрата элементным фтором, позволяющего обеспечить полноту его вскрытия и отделить летучие фториды титана, ниобия, ванадия и кремния от нелетучих - фторидов железа, циркония, гафния и церия. Это позволяет оптимизировать число стадий при дальнейшем применении TiF4 в качестве материала для получения титанового порошка. При электролитическом получении титана обоснована необходимость применения расплава фторидных солей лития, натрия и калия, имеющих состав: LiF (0,465 М)-NaF (0,115 М)-KF (0,42 М), обладающего минимальной температурой плавления (454 °С) и пределами изменения концентрации K2TiF6 (25-30 %). При этом величины плотности тока и выхода по току приближаются к максимальным значениям - 3,5-4,0 А/см2 и 60-65 % соответственно. Содержание примесей в титановом порошке не превышает 0,135 %, что удовлетворяет требованиям для изготовления изделий из компактного титана. The relevance of the study is determined by the creation of a fundamentally new method for the synthesis of titanium powders of high purity from ilmenite ores of Vietnam deposits, containing a mixture of ilmenite with rutile in the heavy fraction. This is one of the priority areas for the integrated development of deposits of rare and rare earth elements in Vietnam. The main aim: selection of conditions, methods and sequence of technological operations for the beneficiation of Vietnamese ilmenite ores and their subsequent chemical processing to obtain high-purity titanium. Objects: ilmenite ore of the Ha Tinh deposit (Vietnam) with a high content of oxides of titanium, iron, zirconium and a low content of silicon, aluminum, rare earth elements, vanadium, as well as ilmenite concentrate obtained as a result of enrichment of the original ilmenite ore. Methods: in the beneficiation process - electrostatic separation, flotation, the use of collectors, activators and depressants added to flotation reagents; in the electrolytic synthesis of titanium - the use of a low-melting eutectic of fluoride salts of alkali metals with the addition of titanium tetrafluoride; selection of the conditions for starting the electrolyzer, cathode current density, current and voltage for the deposition of titanium on the cathode; investigation of the optimal conditions for the release of titanium powder at low temperatures using anhydrous hydrogen fluoride. Results. The prospects of using the methods of electrostatic separation and flotation in the dressing of Vietnamese ilmenite ores of the Ha Tinh deposit are shown. An ilmenite concentrate with a titanium dioxide content of more than 50 % was obtained. The advantages of using the method of direct fluorination of an ilmenite concentrate with gaseous fluorine are substantiated, which makes it possible to ensure both the completeness of the decomposition of the solid phase and to separate the fluorides of titanium, niobium, vanadium and silicon that pass into the gas phase from those remaining in the condensed state - fluorides of iron, zirconium, hafnium and cerium. This allows you to optimize the number of stages in the subsequent processing of titanium tetrafluoride and the synthesis of metallic titanium. In titanium electrolysis, the authors have substantiated the use of composition of the eutectic of fluoride salts of alkali metals LiF (0,465 M)-NaF (0,115 M)- KF (0,42 M), which has a minimum melting point (454 °C) and the range of changes in the concentration of K2TiF6 (25-30 %). In this case, the values of current density and current efficiency approach the maximum values of 3,5-4,0 A/cm2 and 60-65 %, respectively. The content of impurities in titanium powder does not exceed 0,135 %, which meets the requirements for the manufacture of products from compact titanium.

Non-thermal plasma is widely considered as an effective technology for applications in agriculture. Particularly, numerous reports studies have highlighted the role of plasma-activated water (PAW) for seeds germination, plant growth, stress tolerance, and antibacterial ability. The present study investigated the effects of PAW on lettuce (Lactuca Sativa L.) seed germination and seedling growth. PAW was achieved by using an atmospheric pressure dielectric barrier discharge in Ar (50%) –N2 (40%)–O2 (10%) gas mixture for treatment time ranging from 5 to 30 mn. The physicochemical properties of PAW (temperature, pH, electrical conductivity, concentrations of nitrate, nitrite, and hydrogen peroxide) were evaluated. Results show that water-activated during moderate time, 10 to 20 mn, contains reactive oxygen and nitrogen species at relevant concentration levels to have active impacts on seed germination and seedling growth. Germination potential significantly increased by about 117%, 56%, and 77% after 15 mn of treatment, for the first 3 days, respectively, compared to control. For long time PAW (25–30 mn), the germination rate is either constant or decreases. Positive effects of PAW treatments were registered on the growth parameters of seedling including stem and root length, leaf weight, leaf area and chlorophyll content, and the vigor of seedlings. Chlorophyll content significantly increased by 220% for PAW-treated 15 mn and by about 165% for PAW-treated 20 mn, respectively, compared with control. Additionally, PAW induce morphological changes on lettuce seeds which are associated with oxidizing species leading to better water and nutrients uptake.

In this paper, we are interested in entire, non-trivial, non-negative solutions and/or entire, positive solutions to the simplest models of polyharmonic equations with power-type nonlinearity \[ \Delta^m u = \pm u^{\alpha} \quad \text{ in } \mathbb R^n \] with $n \geqslant 1$, $m \geqslant 1$, and $\alpha \in \mathbb R$. We aim to study the existence and non-existence of such classical solutions to the above equations in the full range of the constants $n$, $m$ and $\alpha$. Remarkably, we are able to provide necessary and sufficient conditions on the exponent $\alpha$ to guarantee the existence of such solutions in $\mathbb R^n$. Finally, we identify all the situations where any entire non-trivial, non-negative classical solution must be positive., Comment: 18 pages, 0 figure

International audience; Hibiscus sabdariffa extracts, a rich source of anthocyanin, were subjected to encapsulation in yeast cells. An encapsulation yield (EY) of 208 μg/100 mg of cells and an encapsulation efficiency (EE) of 27%, were reached after optimisation of the ratios (0.5 g wet yeast cells for 5 ml of anthocyanin extracts at 1 g·L−1) and with 10% of ethanol. The storage stability of encapsulated pigments was investigated in water and buffer pH 1.5 at 5 & 37 °C for 10 days and 90 °C for 30 min. The percentage of loss of colour was determined by colourimetry assays. The microparticles made of yeast with or without heat treatment exhibited different protecting effects (P

International audience; Dye plants are present in the everyday life of many ethnic minority groups in Vietnam, ranging from meals, costumes to festivals. The study focuses on those within the Tay Nghe An Biosphere Reserve. This Biosphere Reserve covers an area of 1,303,285 ha of tropical rainforest, one of the 12 main types of ecosystem identified by UNESCO-MAB, in nine mountainous districts. Through our investigation, the use of 40 species of dye plants was recorded. They are mainly employed for dyeing food, textiles, and tools. Additional data about usage were also provided. In particular, one species (Dye Yam – Dioscorea cirrhosa) was recorded for the first time as a source of brown colorant for food. © 2023 International Society for Horticultural Science. All rights reserved.

Measuring electronic Raman scattering (ERS) has become an efficient method for structural characterization of metallic single-wall carbon nanotubes (SWCNT). However, applying this method to other types of SWCNT-based structures, e.g., those with strong van der Waals (VDW) coupling, is currently not well studied. In this work, we combine electron diffraction, Rayleigh and Raman spectroscopies to investigate the ERS process near 36 metallic transitions in 21 individual double-wall carbon nanotubes (DWCNTs) with all types of electronic configurations. We observe the partial suppression of ERS intensity in DWCNTs compared to SWCNTs and mainly attribute it to the effect of dielectric screening of Coulomb interactions. We probe ultra-pure macroscopic multi-chirality DWCNT solutions and identify the role of inhomogeneous broadening in observing ERS peaks in Raman spectra. Based on the experimental findings, we propose an adapted method for the structural identification of DWCNT samples from the ERS data. The obtained results can be generalized to the characterization of the emerging 1D VDW heterostructures based on metallic SWCNTs., DL thanks Prof. S. Rochal and D. Chalin for providing MAPLE code for calculating DWCNT transition energy shifts and W. Van Werveke and M. De Clercq for providing MATLAB code for creating chirality distribution maps. A part of the experimental data (i.e., microscopic Rayleigh and Raman spectra, ED patterns) was obtained and preliminary processed within the framework of Russian Foundation for Basic Research grant 18-32-00397 mol_a. Further data analysis (i.e., developing models for ERS, Raman and Rayleigh spectra fitting) was performed by DL with the support of the postdoctoral grant (12ZP720N) of the Fund for Scientific Research Flanders (FWO). The TEM measurements were performed in the Laboratorio de Microscopias Avanzadas (LMA), Universidad de Zaragoza (Spain). R.A. gratefully acknowledges the support from the Spanish MICINN (PID2019-104739 GB-100/AEI/10.13039/501100011033), Government of Aragon (projects DGA E13-20R (FEDER, EU)) and from the European Union H2020 program “ESTEEM3” (Grant number 823717). V.N.P. acknowledges financial support for NTB calculations from the National Science Fund of Bulgaria under grant KP-06-N38/10 from 06.12.2019. T.T.C acknowledges financial support from Vietnam Academy of Science and Technology (grant number: VAST03.06/22-23). H.N.T, E.F., A.A.Z, J.L.S. and M.P. acknowledge financial support by the ANR GAMBIT project, grant ANR-13-BS10-0014 of the French Agence Nationale de la Recherche. The characterization of the macroscopic UP-DWCNT samples was financially supported by a PhD fellowship for M. Erkens of the Research Foundation of Flanders (FWO, grant number: 11C9220N). D.L. acknowledges the financial support from the University of Antwerp Research Fund (grant BOF KP 43770). D.L., M.A., W.W. and S.C. also acknowledge funding from FWO projects (G040011N, G02112N, G035918N and G036618N).

International audience; The development of efficient bioremediation techniques to reduce aquatic pollutant load in natural sediment is one of the current challenges in ecological engineering. A nature-based solution for metal bioremediation is proposed through a combination of bioturbation and phytoremediation processes in experimental indoor microcosms. The invertebrates Tubifex tubifex (Oligochaeta Tubificidae) was used as an active ecological engineer for bioturbation enhancement. The riparian plant species Typha latifolia was selected for its efficiency in phyto-accumulating pollutants from sediment. Phytoremediation efficiency was estimated by using cadmium as a conservative pollutant known to bio-accumulate in plants, and initially introduced in the overlying water (20 μg Cd/L of cadmium nitrate – Cd(NO3)2·4H2O). Biological sediment reworking by invertebrates' activity was quantified using luminophores (inert particulates). Our results showed that bioturbation caused by tubificid worms' activity followed the bio-conveying transport model with a downward vertical velocity (V) of luminophores ranging from 16.7 ± 4.5 to 18.5 ± 3.9 cm·year− 1. The biotransport changed the granulometric properties of the surface sediments, and this natural process was still efficient under cadmium contamination. The highest value of Cd enrichment coefficient for plant roots was observed in subsurface sediment layer (below 1 cm to 5 cm depth) with tubificids addition. We demonstrated that biotransport changed the distribution of cadmium across the sediment column as well as it enhanced the pumping of this metal from the surface to the anoxic sediment layers, thereby increasing the bioaccumulation of cadmium in the root system of Typha latifolia. This therefore highlights the potential of bioturbation as a tool to be considered in future as integrated bioremediation strategies of metallic polluted sediment in aquatic ecosystems.

International audience; The present work focuses on the use of layered double hydroxides (LDH) as containers for corrosion inhibitors in an epoxy coating. 2-Benzothiazolylthio-succinic acid (BTSA), used as corrosion inhibitor, was intercalated by co-precipitation in magnesium-aluminum layered double hydroxides. The obtained LDH-BTSA was characterized by infrared spectroscopy, X-ray diffraction and scanning electron microscopy. BTSA release from LDH-BTSA in NaCl solutions was investigated by UV-vis spectroscopy. The inhibitive action of LDH-BTSA on carbon steel corrosion was characterized by electrochemical methods and the protective properties of an epoxy coating containing LDH-BTSA were evaluated by electrochemical impedance spectroscopy. It was shown that the BTSA was intercalated in the layered double hydroxide and its loading was about 33%. The BTSA release was dependent on the NaCl concentration in the electrolyte. The polarization curves obtained on the carbon steel sample showed that the LDH-BTSA is an anodic inhibitor. Its efficiency was about 90% at a concentration of 3 g/l. The impedance results showed that the incorporation of LDH-BTSA (3%) in the epoxy matrix improved the corrosion protection of the carbon steel.

Laser dyes Rhodamine B and Perylene Red were incorporated at different relative concentrations into hybrid matrices synthesized using the sol–gel process. Energy transfer from Rhodamine B-donor to Perylene Red-acceptor molecules was observed. Using the different co-doped samples, solid-state dye laser systems were achieved with tuning band position control and increased efficiency with respect to the materials using solely one type of dye.

International audience; A convenient two step "one-pot " four-component synthetic approach was developed for the synthesis of new 6-arylated 5-hydroxy-benzo[a]phenazine derivatives using 2-hydroxy-1,4-naphthoquinone, a variety of aromatic aldehydes, benzene-1,2-diamine, and tetronic acid. In all cases, the synthesis proceeded via three key steps including condensation, Michael addition, and tautomerization. The structure of synthesized compounds was elucidated by spectral data. The inhibitory effect of newly synthesized compounds on nitric oxide (NO) production in lipopolysaccharide (LPS)- stimulated murine macrophage RAW 264.7 cells was assessed. All products exhibited the highly potential NO production inhibition activity with the IC50 values in the range of 3.68-12.14 mu M, indicating the critical role of these compounds in the development of potential anti-inflammation agents.

International audience; This paper presents observations of the F2-layer critical frequency (foF2) and height (hmF2) obtained at Phu Thuy (21.03°N, 105.95°E) and Bac Lieu (9.28°N, 105.73°E) observatories in Vietnam. The data have been examined for all seasons, during high and low solar activities, and compared with the foF2 and hmF2 of the International Reference Ionosphere model (IRI-2012, IRI-2016 two options: AMTB, SHU). Phu Thuy observatory is located at the Northern Crest of the EIA and Bac Lieu in the trough of the EIA, therefore the foF2 values at Phu Thuy are higher than at Bac Lieu. The results show that the IRI-2012 model estimates well the observed foF2 at both stations during high and low solar activities.During high solar activity, models estimate well the calculated hmF2 in summer for both stations. At Phu Thuy in equinoxes AMTB reproduces the night peak better than IRI-2012 and SHU, but higher and later about 2-3 hours, in winter the performance of AMTB is worst. At Bac Lieu, the IRI-2016 options reproduce the night peak and underestimates it, but IRI-2012 does not do it. The pre-noon peaks are underestimated by all the models, except IRI-2012 which overestimates the hmF2 pre-noon peaks at Bac Lieu. At Phu Thuy the pre-noon hmF2 peak is higher than the post-dusk one. At Bac Lieu the post-dusk peak is higher except in summer.During low solar activity, the IRI models estimate relatively well the shape of the calculated hmF2 at both stations. The IRI-2012 models explained better the observed foF2 (deviation of 2.5%) during solstices than during equinoxes (14.2%) for high solar activity. The IRI-2012 model explained better the observed foF2 in spring (7.8%) than in autumn (19.9%), matched better the calculated hmF2 in solstice (5.4%) than during equinoxes (11.8%).The performance of AMTB is worst at both stations for both the high and low solar activity periods except in autumn at Bac Lieu for the low solar year. IRI-2012 is best at the stations for both high and low solar activity periods, except in summer for the high solar activiy year when SHU is the best at Phu Thuy. These results can be used to improve the future IRI model.

International audience; Although the structure and dynamics of planktonic viruses in freshwater and seawater environments are relatively well documented, little is known about the occurrence and activity of these viruses in estuaries, especially in the tropics. Viral abundance, life strategies, and morphotype distribution were examined in the Bach Dang Estuary (Vietnam) during the dry season in 2009. The abundance of both viruses and their prokaryotic hosts decreased significantly from upstream to downstream, probably as the result of nutrient dilution and osmotic stress faced by the freshwater communities. The antibiotic mitomycin-C revealed that the fraction of lysogenic cells was substantially higher in the lower seawater part of the estuary (max 27.1%) than in the upper freshwater area where no inducible lysogens were observed. The question of whether there is a massive, continuous induction of marine lysogens caused by the mixing with freshwater is considered. Conversely, the production of lytic viruses declined as salinity increased, indicating a spatial succession of viral life strategies in this tropical estuary. Icosahedral tailless viruses with capsids smaller than 60 nm dominated the viral assemblage throughout the estuary (63.0% to 72.1% of the total viral counts), and their distribution was positively correlated with that of viral lytic production. Interestingly, the gamma-proteobacteria explained a significant portion of the variance in the 90 nm) was explained by the beta-proteobacteria. Overall, these results support the view that the environment, through selection mechanisms, probably shapes the structure of the prokaryotic community. This might be in turn a source of selection for the virioplankton community via specific affiliation favoring particular morphotypes and life strategies.

Transition metals are essential for a wealth of metabolic reactions, but their concentrations need to be tightly controlled across cells and cell compartments, as metal excess or imbalance has deleterious effects. Metal homeostasis is achieved by a combination of metal transport across membranes and metal binding to a variety of molecules. Gene duplication is a key process in evolution, as emergence of advantageous mutations on one of the copies can confer a new function. Here, we report that the poplar genome contains two paralogues encoding NRAMP3 metal transporters localized in tandem. All Populus species analyzed had two copies of NRAMP3, whereas only one could be identified in Salix species indicating that duplication occurred when the two genera separated. Both copies are under purifying selection and encode functional transporters, as shown by expression in the yeast heterologous expression system. However, genetic complementation revealed that only one of the paralogues has retained the original function in release of metals stored in the vacuole previously characterized in A. thaliana. Confocal imaging showed that the other copy has acquired a distinct localization to the Trans Golgi Network (TGN). Expression in poplar suggested that the copy of NRAMP3 localized on the TGN has a novel function in the control of cell-to-cell transport of manganese. This work provides a clear case of neo-functionalization through change in the subcellular localization of a metal transporter as well as evidence for the involvement of the secretory pathway in cell-to-cell transport of manganese.

International audience; Solar hydrogen generation via water splitting using a monolithic photoelectrochemical cell, also called artificial leaf, could be a powerful technology to accelerate the transition from fossil to sustainable energy sources. Identification of scalable methods for the fabrication of monolithic devices and gaining insights into their operating mode to identify solutions to improve performance and stability represent great challenges. Herein, we report on the one-step fabrication of a CoWO|ITO|3jn-a-Si|Steel| CoWS monolithic device via the simple photoinduced deposition of CoWO and CoWS as oxygen evolution reaction (OER) and onto an illuminated ITO|3jn-a-Si|Steel solar cell using a singledeposition bath containing the [Co(WS4)2]2- complex. In a pH 7 phosphate buffer solution, the best device achieved a solar-to-hydrogen conversion yield of 1.9%. Evolution of the catalyst layers and that of the 3jn-a-Si light-harvesting core during the operation of the monolithic device are examined by conventional tools such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and inductively coupled plasma optical emission spectroscopy (ICP-OES) together with a bipotentiostat measurement. We demonstrate that the device performance degrades due to the partial dissolution of the catalyst. Still, this degradation is healable by simply adding [Co(WS4)2]2- to the operating solution. However, modifications on the protecting indium-doped tin oxide (ITO) layer are shown to initiate irreversible degradation of the 3jn-a-Si light-harvesting core, resulting in a 10-fold decrease of the performances of the monolithic device.

International audience; Laser effects have been obtained with dye-doped hybrid xerogel samples prepared several years ago and stored in different "classical" conditions. Firstly, using the same configuration of the laser cavity as was used 4-5 years ago, we have obtained almost identical laser performances, and slope conversion efficiencies were measured up to 80% and operational lifetimes, with 1-mJ initial output energy and 10-Hz repetition rate of several hundred thousand pulses obtained. Secondly, we have introduced the new pyrromethene 605 dye into a hybrid xerogel matrix and obtained good laser performances similar to the rest of the pyrromethene family

International audience; A low-profile circularly polarized (CP) antenna for a handheld Ultra-High Frequency RadioFrequency Identification (UHF RFID) reader is proposed in this paper. The radiating part on the topsubstrate is composed of three inverted-F elements rotated 120◦around the center of the structure. Apower splitting circuit, placed on the bottom substrate, based on a series transmission line feed deliversequal amplitude to the three IFAs with a sequential 120◦phase shift. Both layers are fabricated onlow-cost FR4 material. This design has a disk form factor with a compact size of 35 mm circle radiusand an 8.6 mm height. The measurement shows good results withS11as lower than−10 dB for thewhole band, 3 dB-axial ratio around 110◦(10 MHz of bandwidth), directivity reaching 4.4 dBic, and thetotal gain of the antenna is 1.9 dBic. In order to validate the proposed antenna performance, a UHFRFID handheld reader is built based on the ThingMagic M6E-Nano module. Different scenarios areinvestigated to validate the proposed antenna performance in a real environment

International audience; Despite the well-known potential of earthworms to modify soil macroporosity , water infiltration through their burrowing activities, it is still difficult to predict which species are more effective in increasing water infiltration. We thus investigated the relationships between soil water infiltration, burrow network properties, morphology and anatomy of a diversity of earthworm species. We sampled 23 earthworm species in northern Vietnam and measured 16 morpho-anatomical traits a priori linked to their feeding, vertical distribution or burrowing behaviour. One individual was then incubated in a repacked soil core for four weeks under laboratory conditions, each in four replicates. After incubation, burrow network properties were assessed using X-ray computed tomography , soil saturated hydraulic conductivity was measured using the falling head method. We found large differences among species belonging to similar or different ecological categories in their effect on soil saturated hydraulic conductivity. We observed neutral to positive effects with an increase of up to 30-fold compared to cores without earthworms. The effect of earthworms on soil hydraulic conductivity was well pre-dicted by burrow network properties (volume and continuity of burrows) or morpho-anatomical traits (body weight, circular and longitudinal muscles thickness) using the random forest regression models (R2 > 0.95 in both cases). Earthworms with a large body weight and circular and longitudinal muscle thicknesses have the highest probability of increasing soil saturated hydraulic conductivity compared to other species. In addition, we showed from the coinertia analysis that body weight and circular and longitudinal muscle thickness were positively associated with the volume and continuity of burrows. Our findings therefore illustrate the power of employing a trait-based approach to predict the effect of non-Lumbricidae earthworms on water infiltration in comparison to the classical ecological category approach. Such trait information could be used to prioritize practices that favour the expression of more desirable earthworm traits to increase soil water infiltration.

International audience; As flood events are expected to become more frequent due to climate change, investigating how overland flow exports terrestrial nutrients, carbon and living organisms into aquatic systems is essential for understanding both soil and stream ecosystem status. Here we assessed how dissolved organic carbon (DOC), total suspended sediments (TSS), and stream bacterial diversity responded to stream discharge and overland flow during stormflow in a tropical catchment. A higher humification index and a decreasing ratio of allochthonous to autochthonous DOC indicated that DOC from soils was exported to stream during the flood. The delta C-13 and delta N-15 of particulate matter was indicative of a source in the cultivated areas of the upper catchment and of subsurface soils (stream banks and gullies) in the downstream section. Bacterial richness of particle-attached (PA) and the free-living (FL) fractions increased with the flood progression in the upstream section. Moreover, the community structure of the PA fraction in the stream was more similar to that of overland flow than was the FL fraction. This suggests that the soil PA bacterial community was washed-out with overland flow during the flood recession. The relative contribution of sources and the composition of TSS, rather than hydrological regime, significantly drove the composition of bacterial community. In conclusion, our results emphasize that overland flow during a flood event strongly influences the structure of stream bacterial communities further underlining the biological connectivity between terrestrial runoff and stream flow.

A new racemic xanthone, garmckeanin A (1), and eight known analogs 2-9 were isolated from the ethyl acetate (AcOEt) extract of the Vietnamese Garcinia mckeaniana leaves. Their structures were determined by MS and NMR spectral analyses and compared with the literature. The AcOEt extract showed good cytotoxicity against cancer cell lines KB, Lu, Hep-G2 and MCF7, with IC50 values of 5.40-8.76 μg/mL, and it also possessed α-glucosidase inhibitory activity, with an IC50 value of 9.17 μg/mL. Garmckeanin A (1) exhibited inhibition of all cancer cell lines, with an IC50 value of 7.3-0.9 μM. Allanxanthone C (5) successfully controlled KB growth, with an IC50 value of 0.54 μM, higher than that of the positive control, ellipticine (IC50 1.22 μM). Norathyriol (8) was a promising α-glucosidase inhibitor, with an IC50 value of 0.07 μM, much higher than that of the positive control, acarbose (IC50 161.0 μM). The interactions of the potential α-glucosidase inhibitors with the C- and N-terminal domains of human intestinal α-glucosidase were also investigated by molecular docking study. The results indicated that bannaxanthone D (2), garcinone E (4), bannaxanthone E (6), and norathyriol (8) exhibit higher binding affinity to the C-terminal than to the N-terminal domain through essential residues in the active sites. In particular, compound 8 could be assumed to be the most potent mixed inhibitor.

Fucoidans are sulfated, fucose-rich marine polysaccharides primarily found in cell walls of brown seaweeds (macroalgae). Fucoidans are known to possess beneficial bioactivities depending on their structure and sulfation degree. Here, we report the first functional characterization and the first crystal structure of a prokaryotic sulfatase, PsFucS1, belonging to sulfatase subfamily S1_13, able to release sulfate from fucoidan oligosaccharides. PsFucS1 was identified in the genome of a Pseudoalteromonas sp. isolated from sea cucumber gut. PsFucS1 (57 kDa) is Ca2+ dependent and has an unusually high optimal temperature (68 °C) and thermostability. Further, the PsFucS1 displays a unique quaternary hexameric structure comprising a tight trimeric dimer complex. The structural data imply that this hexamer formation results from an uncommon interaction of each PsFucS1 monomer that is oriented perpendicular to the common dimer interface (~ 1500 Å2) that can be found in analogous sulfatases. The uncommon interaction involves interfacing (1246 Å2) through a bundle of α-helices in the N-terminal domain to form a trimeric ring structure. The high thermostability may be related to this unusual quaternary hexameric structure formation that is suggested to represent a novel protein thermostabilization mechanism.

Off the coast of Vietnam, two recent events seem to have contributed to the death of coral reefs: the rapid invasion of a small marine snail called Drupella, and the emergence of a disease that spreads over corals. We decided to investigate whether there is a link between the corals, the snails, and the disease. We analyzed the mucus covering the surface of corals, both in healthy corals and those infested by Drupella snails. Mucus produced by corals is usually full of helpful microbes, protecting the corals from harmful microbes that can make them ill or kill them. Our analyses showed that, when Drupella eats corals, the snail also removes one of the corals’ primary defenses by eliminating most of the tiny protectors in their mucus. This allows harmful microbes to cause additional damage to the corals.

The mean trophic position (TP) of mesozooplankton largely determines how much mass and energy is available for higher trophic levels like fish. Unfortunately, the ratio of herbivores to carnivores in mesozooplankton is difficult to identify in field samples. Here, we investigated changes in the mean TP of mesozooplankton in a highly dynamic environment encompassing four distinct habitats in the southern South China Sea: the Mekong River plume, coastal upwelling region, shelf waters, and offshore oceanic waters. We used a set of variables derived from bulk and amino acid nitrogen stable isotopes from particulate organic matter and four mesozooplankton size fractions to identify changes in the nitrogen source and TP of mesozooplankton across these habitats. We found clear indications of a shift in N sources for biological production from nitrate in near‐coastal waters with shallow mixed layer depths toward an increase in diazotroph‐N inputs in oceanic waters with deep mixed layer depths where diazotrophs shaped the phytoplankton community. The N source shift was accompanied by a lengthening of the food chain (increase in the TP). This may provide further support for the connection between diazotrophy and the indirect routing of N through the marine food web. Our combined bulk and amino acid δ15N approach also allowed us to estimate the trophic enrichment (TE) of mesozooplankton across the entire regional ecosystem. When put in the context of literature values, a high TE of 5.1‰ suggested a link between ecosystem heterogeneity and the less efficient transfer of mass and energy across trophic levels., Plain Language Summary: Zooplankton are one of the central pillars of the marine food web and form an important link between the production of organic matter by phytoplankton and biomass at higher trophic levels (e.g., fish). Of particular interest are mesozooplankton (0.2–20 mm in size), which encompass a diverse assemblage of animals utilizing a range of feeding strategies, including herbivory, omnivory, and carnivory. Since mass and energy are lost with each trophic step, their prevailing feeding strategy determines the availability of mass and energy to the upper food web. The exact relationship between carnivores and herbivores in mesozooplankton has so far only been studied with complex experiments or in homogenous environments. We have now resolved zooplankton feeding relationships in a highly dynamic marine environment. Specifically, we used stable nitrogen isotopes in amino acids and bulk organic matter in combination with a habitat‐delineating method for phytoplankton to directly determine the ratio of carnivores to herbivores in zooplankton from dynamic habitats in the South China Sea. The mass and energy transfer across trophic levels is less efficient in such variable marine environments compared to stable open ocean systems. These findings represent a big step toward understanding the dynamics of planktonic food webs in general., Key Points: Trophic structure of mesozooplankton is regulated by similar environmental factors such as phytoplankton assemblages. Diazotrophy and nutrient availability correlated with enhanced mesozooplankton carnivory in a complex tropical marine ecosystem. Mass and energy transfer across trophic levels of planktonic food webs are less efficient in spatially and temporally variable ecosystems., Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659, National Foundation for Science and Technology Development (NAFOSTED) http://dx.doi.org/10.13039/100007224, National Aeronautics and Space Administration (NASA) http://dx.doi.org/10.13039/100000104, Schmidt Ocean Institute, National Science Foundation (NSF) http://dx.doi.org/10.13039/100000001, https://doi.org/10.5061/dryad.bk3j9kdbv

International audience; Fe/S catalyst generated in situ from FeCl2•4H2O and elemental sulfur S8 in the presence of a tertiary amine as a base was found to catalyze efficiently a 6eredox condensation of o-nitrophenols with acetophenones and methylquinolines. The condensed products 2benzoyl benzoxazoles and 2-quinolyl benzoxazoles were obtained in reasonable yields with water as the only byproduct at temperature as low as 80 °C.

International audience; Multitemporal synthetic aperture radar (SAR) interferometry (InSAR) is a widely used technique to measure the ground subsidence and has already shown its ability to map such phenomena on a large spatial scale with millimetric accuracy from space. In Vietnam, to have independent SAR data for surface risk applications, a new X-band SAR mission (JV-LOTUSat) has been scheduled for launch for the 2019-2020 timeframe. However, Vietnam is located in tropical regions where their conditions are impacted by strong atmosphere. The aim of this article is to provide a better understanding of the capabilities of the X-band for estimating the ground subsidence under tropical atmospheric conditions. Analysis is carried out on two stacks, TerraSAR-X and Cosmos SkyMed X-band, from 2011 to 2014 in Ha Noi. We show that the results on the ground subsidence from InSAR processing can describe consistently the subsidence area based on ground measurements. This article demonstrates that the InSAR technique can be effective at detecting and estimating the subsidence phenomena even with the X-band and under conditions typical of tropical regions. The displacement results from TerraSAR-X and Cosmos SkyMed datasets are consistent, with a correlation coefficient (R2) of 0.91 for the period during which their coverage overlaps. Groundwater overexploitation is one of the main causes of the ground subsidence in Ha Noi. This study provides strong support for the scientific potential of the X-band SAR space-borne mission in Vietnam and other tropical countries because it demonstrates the feasibility of the ground subsidence estimates by the X-band SAR, even in conditions impacted by strong atmosphere.

A viscosity approach is introduced for the Dirichlet problem associated to complex Hessian type equations on domains in $\C^n$. The arguments are modelled on the theory of viscosity solutions for real Hessian type equations developed by Trudinger. As consequence we solve the Dirichlet problem for the Hessian quotient and special Lagrangian equations. We also establish basic regularity results for the solutions., 29 pages

International audience; Background: The production of secondary metabolites through the culture of entire plants is of great interest. Soilless culture, such as hydroponics, enables the control of plant growth and metabolism. Specific environmental conditions must be developed to maximize the productivity of medicinal plants used as efficient natural bioreactors. Methods: The nutrient solution of newly established hydroponic cultures ofDatura innoxia Mill. were inoculated with Agrobacterium rhizogenes (A.r.) wild strains (TR7, TR107, 11325 or 15834). Growth and the alkaloid contents of roots and aerial parts were analyzed. Axenic cultures were also performed with modified TR7 strains containing the egfp or gus reporter gene. In vitro isolated root cultures enabled the phenological and molecular demonstration of gene transfer. Results: A.r.TR 7 led to a greater improvement in plant secondary metabolism and growth. Positive expression of the reporter genes occurred. Isolation and subculture of some of the roots of these plants showed a hairy root phenotype; molecular tests proved the transfer of bacterial genes into the roots isolated from the plants. Conclusions: Hyoscyamine and scopolamine productivity is enhanced after A.r. inoculation in the nutrient solution of hydroponic plants. Transformation events occur in the original roots of the plants. This leads to chimeric plants with a part of their roots harboring a hairy root phenotype. Such semi-composite plants could be used for successful specialized metabolite bioproduction in greenhouses.

In this paper, Spherical Cap Harmonic Analysis (SCHA) method was applied to model the geomagnetic field over Vietnam and adjacent area between 15°S and 25°N latitude and 90°E and 130°E in longitude by using magnetic data recorded on CHAMP and Swarm satellites. The characteristic parameters of the method were set at the maximum index Kint = 8 for internal fields, the spherical cap half-angle θ0 = 20°. The regional geomagnetic field over Vietnam and adjacent areas are modelled for the two epochs (2007.0 and 2015.0). Comparison between the SCHA regional geomagnetic field intensity and its time variation with those from IGRF was carried out. The geomagnetic field intensity $$ (E_{F}^{SCHA} ) $$ from SCHA model varies between −90 and 98 nT for epoch 2007.0 and between −139 and 143 nT for epoch 2015.0; however, the trends of their time variations are the same over Vietnam. The RMS between the magnetic components from SCHA model and ground observations are in the same order. The amplitude of time variation of total field intensity from SCHA model is about tens nT greater than from IGRF over Vietnam.

International audience; This work offers a novel pathway to prepare cryptomelane manganese oxides nanosheets as an superior catalyst for the catalytic combustion of oxygenated volatile organic compounds. The tunnel cryptomelane manganese oxides nanosheets were prepared from layered birnessite via simultaneously tuning pH and molar ratio (ROK) of the redox-precipitation between oxalic acid and KMnO4. Thus, few-layered cryptomelane nanosheets possessing the most predominantly exposed (211) facet are generated at low pH (5.2–5.6), which intensifies the surface area of thin crystal cryptomelane nanosheets up to 177 m2 g-1 and weakens Mn-O bonds. Moreover, high ROK results in low manganese average oxidation state (AOS), greater oxygen vacancies and better low-temperature reduction and oxygen mobility. Such features significantly maneuver the catalytic activity of the cryptomelane nanosheets catalysts for the complete oxidation of oxygenated volatile organic compound (e.g., 2-propanol, acetone) at low temperature (170–230 °C). Moreover, the catalysts show high stability for 48 h. The presented catalyst discloses an avenue to address current obstacles in the catalytic oxidation of volatile organic compounds.

In aquatic environments, assessment of microplastic concentrations is increasing worldwide but environments from developing countries remain under-evaluated. Due to disparities of facilities, financial resources and human resources between countries, protocols of sampling, analysis and observations used in developed countries cannot be fully adapted in developing ones, and required specific adaptations. In Viet Nam, an adapted methodology was developed and commonly adopted by local researchers to implement a microplastic monitoring in sediments and surface waters of 21 environments (rivers, lakes, bays, beaches) of eight cities or provinces. Microplastic concentrations in surface waters varied from 0.35 to 2522 items m-3, with the lowest concentrations recorded in the bays and the highest in the rivers. Fibers dominated over fragments in most environments (from 47% to 97%). The microplastic concentrations were related to the anthropogenic pressure on the environment, pointing out the necessity in a near future to identify the local sources of microplastics.

International audience; The endophytic bacteria were isolated from coffee roots and seeds in Vietnam and identified with 16S rDNA sequencing as belonging to the Actinobacteria, Firmicutes and Proteobacteria phyla with the Nocardia, Bacillus and Burkholderia as dominant genera, respectively. Out of the thirty genera recovered from Coffea canephora and Coffea liberica, twelve were reported for the first time in endophytic association with coffee including members of the genera Brachybacterium, Caballeronia, Kitasatospora, Lechevalieria, Leifsonia, Luteibacter, Lysinibacillus, Mycolicibacterium, Nakamurella, Paracoccus, Sinomonas and Sphingobium. A total of eighty bacterial endophytes were characterized in vitro for several plant growth promoting and biocontrol traits including: the phosphate solubilization, the indolic compounds, siderophores, HCN, esterase, lipase, gelatinase and chitinase production. A subset of fifty selected bacteria were tested for their potential as biocontrol agents with in vitro confrontations with the fungal pathogen Fusarium oxysporum as well as the coffee parasitic nematodes Radopholus duriophilus and Pratylenchus coffeae. The three most efficient isolates on F. oxysporum belonging to the Bacillus, Burkholderia, and Streptomyces genera displayed a growth inhibition rate higher than 40%. Finally, five isolates from the Bacillus genus were able to lead to 100% of mortality in 24 h on both R. duriophilus and P. coffeae.

International audience; Hydrogen-bonding upper critical solution temperature (UCST) thermosensitive nanogels based on poly(N-acryloyl glycinamide) (PNAGA) are synthesized by photo-reversible addition-fragmentation chain transfer mediated polymerization-induced self-assembly (photo-RAFT PISA) in aqueous dispersion using N,N′-methylenebis(acrylamide) as crosslinker and poly(oligo(ethylene glycol) methyl ether acrylate) as both stabilizer and macromolecular chaintransfer agent (macro-CTA). Highly stable, spherical nanogels with narrow polydispersity are efficiently produced up to complete monomer conversion within 1 h under UV irradiation at low temperature (3 °C). The thermosensitivebehavior of PNAGA-based nanogels, as assessed by dynamic light scattering and UV–vis spectrophotometry, exhibits reversible heating-induced swelling and cooling-induced shrinking corresponding to the expected UCST behavior.The hydrodynamic diameter, swelling ratio, and phase transition temperature of nanogels can be tuned by modifying the initial molar ratio of monomer-tomacro-CTA and the amount of crosslinker in the photo-RAFT PISA of NAGA

In this paper, we study the Cauchy–Dirichlet problem for Parabolic complex Monge–Ampere equations on a strongly pseudoconvex domain using the viscosity method. We extend the results in Eyssidieux et al. (Math Ann 362:931–963, 2015) on the existence of solution and the convergence at infinity. We also establish the Holder regularity of the solutions when the Cauchy–Dirichlet data are Holder continuous.

International audience; Racemic ethyl 2,3‐dibromopropionate, commercially available at low price, is a key intermediate used in the synthesis of several heterocycle fragments, which are present in many biologically active compounds. Surprisingly, the enantiomers are not commercially available and have never been described in the literature. In this work, we undertook two different strategies to obtain these enantiomers, which are enantioselective synthesis and preparative HPLC enantioseparation of commercially available racemate on multigram scale. The first strategy has proved inadequate because racemization occurred during the synthesis (ee ≈ 9‐50%). Conversely, the second strategy produced a very good enantioseparation of commercially available racemate (ee > 99.5% for both enantiomers) on multigram scale.

International audience; Bats have been recognized as an exceptional viral reservoir, especially for coronaviruses. At least three bat zoonotic coronaviruses (SARS-CoV, MERS-CoV and SARS-CoV-2) have been shown to cause severe diseases in humans and it is expected more will emerge. One of the major features of CoVs is that they are all highly prone to recombination. An extreme example is the insertion of the P10 gene from reoviruses in the bat CoV GCCDC1, first discovered in Rousettus leschenaultii bats in China. Here, we report the detection of GCCDC1 in four different bat species (Eonycteris spelaea, Cynopterus sphinx, Rhinolophus shameli and Rousettus sp.) in Cambodia. This finding demonstrates a much broader geographic and bat species range for this virus and indicates common cross-species transmission. Interestingly, one of the bat samples showed a co-infection with an Alpha CoV most closely related to RsYN14, a virus recently discovered in the same genus (Rhinolophus) of bat in Yunnan, China, 2020. Taken together, our latest findings highlight the need to conduct active surveillance in bats to assess the risk of emerging CoVs, especially in Southeast Asia.

International audience; Two new species of scorpion belonging to the family Pseudochactidae and to the genus Vietbocap are described based on specimens collected in the Thien Duong cave, which belongs to the Vom cave system, in the Phong Nha–Ke Bang National Park, Quang Binh Province, Vietnam. The previously described species from this cave, Vietbocap thienduongensis Lourenço & Pham, 2012 was collected in the initial section of the cave (1500 to 1800 m from the cave entrance) and proved to be a true troglobitic element. The diagnosis of this species, only known from males, is completed based on females collected at 750 m from the cave entrance. The two new species described here were collected respectively at 3000 and 5000 m from the cave entrance and are also true troglobitic elements, very similar to V. thienduongensis, but showing some clear morphological differences. This observed situation suggests a possible case of speciation within the cave system, the first one ever reported for scorpions. The population found at 5000 m from the entrance of the cave is a total new record of distance from a cave entrance for scorpions.; Deux nouvelles espèces de scorpion appartenant à la famille des Pseudochactidae et au genre Vietbocap sont décrites à partir d’exemplaires collectés dans la grotte Thien Duong, laquelle appartient au système des grottes Vom dans le parc national Phong Nha–Ke Bang dans la province de Quang Binh, Vietnam. La seule espèce déjà décrite de cette grotte, Vietbocap thienduongensis Lourenço & Pham, 2012, a été collectée dans la partie initiale de celle-ci (entre 1500 et 1800 mètres de l’entrée) et a été confirmée comme un véritable élément troglobie. La diagnose de cette espèce, connue uniquement à partir des mâles, est complétée à partir de femelles collectées à 750 m de l’entrée de la grotte. Les deux nouvelles espèces décrites à présent ont été collectées respectivement à 3000 et 5000 m de l’entrée de la grotte et sont également des éléments troglobies, plutôt similaires à V. thienduongensis, mais avec des différences morphologiques bien nettes. La situation observée suggère un possible cas de spéciation à l’intérieur de la grotte, le premier signalé chez les scorpions. La population trouvée à 5000 m de l’entrée de la grotte représente un record absolu de distance de l’entrée d’une grotte pour des scorpions.

International audience; Quantitatively monitoring the thickness reduction of a pipe by using magnetic flux density method remains a major challenge due to the small and gradual change in magnetic flux density over a long distance along a pipe. This signal change is hindered in the background signal of a detector that has a high temperature dependence and unstable background signal. In this paper, we verify the effectiveness of magnetic flux density method in quantitatively monitoring thickness reduction through simulation and experimental verification. Experimental results show that the proportion of magnetic signal change is 1.4 mT per 10% wall loss. To support this quantitative approach, we optimise an original ultra-high-sensitivity planar Hall sensor with high thermal stability and stable background signal versus time for measurement of the magnetic field over a wide range from 0 to 50 mT. The quantitative measurements were validated on test pipes with varying thickness steps of 0.5 mm.

International audience; Soil is considered as a non-renewable resource, which may be lost in sloping land more rapidly than it is formed thus leading to loss of fertility and ecosystem deterioration. We hypothesized that earthworms could counteract this process due to their cast forming activity. To test this hypothesis, we quantified the production of casts in small plots of 0.25 m2 established in three vegetation units (woodland, shrubland and meadow) in a catchment of 46 ha for 2.5 years in relation to their (micro-) pedoclimatic conditions. We also assessed the impact of cast formation on water runoff and soil detachment. Moreover, we quantified the mass of casts deposited in the entire catchment on a regular grid of 50 m and we measured soil erosion at the outlet of the catchment. Our results showed a high and variable production of casts (from 16 to 219 t ha−1 year−1) depending on vegetation, season and year. The mass of casts found in the entire catchment represented on average 7.4 t ha−1 with an annual production rate of 35 t ha−1. Since the annual erosion rate measured for the entire catchment (3 t ha−1 year−1) was much lower than the cast production rate, our results indicated that most of the soil bioturbated by earthworms remained in the catchment. Indeed, water runoff and soil detachment measured in small plots showed that casts were not transported in the water runoff but degraded by raindrop impacts with the material remaining at the place of deposition. This process led to the generating of a new soil horizon at the culmination point of the catchment of up to 6.5 cm after 2.5 years. We conclude that the surface activity of anecic earthworms could influence soil generation at scale and conteract the effects of soil erosion.

C.M. Shand et al. -- 6 pags., 3 figs., tab. --Open Access funded by Creative Commons Atribution Licence 4.0, We report on the measurement of new low-lying states in the neutron-rich Zn nuclei via in-beam γ-ray spectroscopy. These include the 4 →2 transition in Zn, the 2 →0 and 4 →2 transitions in Zn, and low-lying states in Zn were observed for the first time. The reduced E(2 ) energies and increased E(4 )/E(2 ) ratios at N=52, 54 compared to those in Zn attest that the magicity is confined to the neutron number N=50 only. The deduced level schemes are compared to three state-of-the-art shell model calculations and a good agreement is observed with all three calculations. The newly observed 2 and 4 levels in Zn suggest the onset of deformation towards heavier Zn isotopes, which has been incorporated by taking into account the upper sdg orbitals in the Ni78-II and the PFSDG-U models., All UK authors are supported by the Science and Technology Facilities Council (STFC). The development of MINOS and the core MINOS team have been supported by the European Research Council through the ERC Grant No. MINOS-258567. A. Jungclaus was supported by the Spanish Ministerio de Economía y Competitividad under contract FPA2014-57196-C5-4-P. Authors from Cologne were supported by German BMBF Grant No. 05P15PKFNA. Authors from TU Darmstadt were supported by German BMBF Grant No. 05P12RDFN8 and 05P15RDFN1. L.X. Chung and B.D. Linh would like to acknowledge Vietnam Ministry of Science and Technology for the support, and Radioactive Isotope Physics Laboratory of the RIKEN Nishina Center for supporting their stay during the experiments.

International audience; River delta shorelines composed of sand may be characterized by complex spatial and temporal patterns of erosion and accretion even when sand supply is readily available. This is especially the case for deltas with multiple mouths subject to significant wave and tide influence. High-resolution topographical and wave and current measurements were conducted from 2010 to 2012 at Ba Ding beach, a popular resort located on the largest of the multiple inter-distributary plains of the Mekong River delta. Ba Dang beach is a mesotidal, multiple bar-trough system. The upper beach corresponds to the current active beach ridge in the sequence of ridges that have marked the progradation of the inter-distributary delta plains, and is capped by a low foredune that protects villages and agricultural land from marine flooding. During the low river-flow season, the beach is characterized by Northeast monsoon waves and strong longshore currents that transport sediment towards the southwest. Weaker longshore currents towards the northeast are generated by Southwest monsoon waves during the high river-flow season. Ba Dang beach underwent strong erosion between 2010 and 2012, following a phase of massive accretion. In 2012, this erosion resulted in breaching of the foredune, contributing to concerns that the Mekong delta had become vulnerable to retreat. The local erosion at Ba Dang needs to be considered, however, in the broader context of delta shoreline morphodynamics, which involves space- and time-varying patterns of beach accretion and erosion. These patterns are the present expressions of plan-view beach-ridge morphology in the delta, which is characterized by flaring and truncations that reflect changing beach morphodynamics in the course of deltaic progradation. We surmise that these patterns are related to complex interactions involving river water and sediment discharge, waves and wave-generated longshore currents, tidal currents, and shoreline orientation.

A local survey of Chrysomelidae in a coastal area of some 10 km2 in the Núi Chúa National Park (Ninh Thuan, S Vietnam) yielded a remarkable number of Galerucinae. Most of them, up to 18 species, could be ascribed to the informal group Monoleptites, i.e. galerucines with very long first metatarsomere, longer than the remaining four combined. These representatives of Monoleptites constitute a strongly supported monophyletic group based on a combined analysis of one mtDNA (cox1) and one nuclear (wnt) marker, and include up to thirteen species which are not recognisable as species previously described or reported from Vietnam or neighbouring countries. These species are described herein, including eleven species tentatively assigned to the genus Monolepta Chevrolat (M. decretasp. nov., M. deminutasp. nov., M. densopunctatasp. nov., M. dubiasp. nov., M. fluctuanssp. nov., M. fuscicornesp. nov., M. interruptomarginatasp. nov., M. ochraceasp. nov., M. praetextasp. nov., M. quotidianasp. nov. and M. thomaswagnerisp. nov.) and two to the genus Paleosepharia Laboissière (P. frontissp. nov. and P. nuichuasp. nov.). Moreover, the name Desbordeleptanom. nov. is proposed to remove the homonymy of Desbordesius Laboissière, 1936 nec Maindron, 1906, and the spermatheca of D. picea (Kimoto) and male and female genitalia of M. dalatica Kimoto and M. semicostata Kimoto are described for the first time. Finally, a molecular analysis of putative diets based on the identification of chloroplastic psbA-trnH sequences obtained from total DNA extractions of the beetles, provides with some robust hypotheses for the diet of these animals, showing that they are polyphagous, and able to utilise a wide range of mainly eudicots in their environment. The results of this study roughly represent a 12% increase in the number of known species of the Monoleptites group in Vietnam and highlight the need for a profound revision of generic attributes in this group., This work was possible thanks to funds from the Spanish Ministry of Economy and Competitiveness to promote a Scientific Cooperation Agreement between the Spanish High Research Council (CSIC) and the Vietnamese Academy of Sciences and Technology (VAST).

6 pags., 4 figs., 1 tab., We report on the observation of a microsecond isomeric state in the single-proton-hole, three-neutron-particle nucleus In-134. The nuclei of interest were produced by in-flight fission of a U-238 beam at the Radioactive Isotope Beam Factory at RIKEN. The isomer depopulates through a gamma ray of energy 56.7(1) keV and with a half-life of T-1/2 = 3.5(4) mu s. Based on the comparison with shell-model calculations, we interpret the isomer as the I-pi = 5(-) member of the pi 0g(9/2)(-1) circle times nu 1f(7/2)(3) multiplet, decaying to the I-pi = 7(-) ground state with a reduced-transition probability of B(E2; 5(-) -> 7(-)) = 0.53(6) W.u. Observation of this isomer, and lack of evidence in the current work for a I-pi = 5(-) isomer decay in In-132, provides a benchmark of the proton-neutron interaction in the region of the nuclear chart >southeast> of Sn-132, where experimental information on excited states is sparse., This experiment was performed at RI Beam Factory operated by RIKEN Nishina Center and CNS, University of Tokyo. This research was sponsored in part by the Office of Nuclear Physics, U.S. Department of Energy under Awards No. DE-FG02-96ER40983 (UTK) and No. DE-AC05- 00OR22725 (ORNL), and by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Award No. DE-NA0002132, by the National Science Foundation under Grants No. PHY1430152 (JINA Center for the Evolution of the Elements), No. PHY-1565546 (NSCL), and No. PHY1714153 (Central Michigan University), by the Polish National Science Center under Contract No. UMO-2015/18/E/ST2/00217, by JSPS KAKENHI (Grants No. 14F04808, No. 17H06090, No. 25247045, and No. 19340074), by the UK Science and Technology Facilities Council ST/P005314/1, by NKFIH (NN128072), by the Janos Bolyai research fellowship of the Hungarian Academy of Sciences, by the UNKP-18- 4-DE-449 New National Excellence Program of the Ministry of Human Capacities of Hungary, by Spanish Ministerio de Economia y Competitividad grants (FPA2017- 83946-C2-1-P, FPA2011-28770-C03-03, FPA2014-52823- C2-1-P, FPA2014-52823-C2-2-P, FPA2014-57196-C5-4-P, FPA2017-84756-C4-2-P, SEV-2014-0398, and IJCI-2014- 19172), by European Commission FP7/EURATOM Contract No. 605203, by the UK Nuclear Data Network funded by the UK Science and Technology Facilities Council Grant No. ST/N00244X/1, by the National Research Foundation (NRF) in South Korea (Grants No. 2016K1A3A7A09005575 and No. 2015H1A2A1030275), and by the Natural Sciences and Engineering Research Council of Canada (NSERC) via the Discovery Grants No. SAPIN-2014-00028 and No. RGPAS 462257-2014. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada. N.P.L. receives funding from the UK Department of Business Energy and Industrial Strategy (BEIS) via the NMS program. Shell-model calculations are supported by the National Natural Science Foundation of China 11775316. L.H.K. acknowledges Vietnam Academy of Science and Technology for support under the Program of Development in the Field of Physics by 2020–Study of unstable nuclei beam induced nuclear reaction at RIKEN. V.H.P. would like to express his deep gratitude to the RIKEN institute for the support during the term of IPA program at RIKEN Nishina Center.

International audience; In this article, we perform surface-enhanced Raman scattering (SERS) with a periodically corrugated metallic substrate obtained by evaporating an Ag film onto an artificial opal crystal, which is a self-assembled lattice of SiO2 600-nm spheres. These metallic-film-on-nanosphere (MFON) surfaces are characterized by scanning electron microscopy for different Ag film thicknesses ranging from 44 to 620 nm. Raman scattering spectra are measured for two different types of quantum dots, CdTeSe quantum dots (QDs) and graphene quantum dots (GQDs). We are able to show that enhancement of the Raman spectra can be obtained for all MFON substrates and for both types of QDs. For both CdTeSe and graphene quantum dots, the strongest SERS effect was observed in samples with 135 nm Ag thickness. This is attributed to the formation of hot spots in the nanogap dips of the Ag film.

International audience; A new modified geranylated flavonoid, 6-(8″-hydroxy-3″,8″-trimethyloct-2″-enyl)-kaempferol (1), along with seventeen known compounds (2-18) were isolated from the fruits of Macaranga denticulata. Their structures were established by spectral analysis, such as mass spectrometry, 1D-NMR, and 2D-NMR. Compounds 1-13 were evaluated for their cytotoxicity against seven cancer cell lines MCF-7, HepG2, Hep3B, Lu-1, Hela, KB, A549. The new geranylated flavonoid 1 showed a moderate cytotoxic activity against the A549 cell line with IC50 value of 16.0 µM. Compound 9 showed the highest cytotoxic activities against KB, HepG2, Lu-1, and MCF7 cell lines with IC50 values of 0.6, 0.8, 1.3, and 1.2 µM, respectively.

International audience; This work presents the results on the fabrication, structural and optical properties of CdTeSe/ZnTe and CdTeSe/ZnSe n monolayers (ML) (with n = 0,1,2,4 and 6 being the nominal shell monolayer thickness) ternary alloyed core/shell quantum dots (QDs). Transmission electron microscopy has been used to observe the shape and size of the QDs. These QDs crystallize at the zinc-blende phase. Raman scattering has been used to characterize the CdTeSe QDs’ alloy composition in the fabrication and coating processes. The Raman spectrum of CdTeSe QDs, in the frequency range from 100 cm−1 to 300 cm−1, is a composite band with two peaks at 160 cm−1 and 192 cm−1. When the thickness of the ZnTe shell is 4 ML, the peak of the Raman spectrum only appears at 160 cm−1. For the ZnSe 4 ML shell, the peak only appears at ∼200 cm−1. This shows that the nature of the CdTeSe QDs is either CdTe-rich or CdSe-rich depending on the shell of each sample. The shell thickness of 2 ML does not change the ternary core QDs’ crystalline phase. The absorption and photoluminescence spectra show that the absorption and emission bands can be shifted to 900 nm, depending on each ternary alloyed QD core/shell sample. This near-infrared spectrum region is suitable␣for applications in solar cells.

International audience; The combination of a sub-microsecond pulsed dielectric barrier discharge with Pd/gamma-Al2O3 catalyst was investigated for the oxidation of low concentration of methane, propene, and toluene in air at atmospheric pressure. The systematic comparison of the plasma-catalysis with the thermal-catalysis and the plasma-alone have been made for temperature window of 20–400 C and energy deposition in the range 23–148 J L-1. To emphasis the reactivity of plasma produced species on the activation of the catalyst, two reactor configurations were used [in-plasma catalysis (IPC), and post-plasma catalysis (PPC)]. Fourier transform infrared spectrometer was used to follow the VOCs conversion and to quantify the mineralized products. The plasma-catalyst combination leads to higher VOCs conversion and decreases the catalyst activation temperature in both IPC and PPC configurations. For hybrid system, the light-off temperature is always lower than those observed for catalytic oxidation. In addition, the formation of the by-products such as formaldehyde, formic acid, and ozone was reduced significantly. A significant synergetic effect of hybrid plasma-catalytic system is not really observed in the presence of CH4 and C3H6. However, for C7H8 oxidation the synergetic effect was demonstrated at low temperature (\150 C) for the IPC configuration.

International audience; Mugil cephalus sensu lato is a globally distributed complex of cryptic species whose distribution range and evolutionary history remains largely unknown. In the North West (NW) Pacific three species have been identified genetically among fish described morphologically as M. cephalus. Their distribution ranges are largely parapatric and has been proposed to mirror different thermal preferences. To date, few samples have been analyzed from South China Sea, which limits inferences on the evolutionary history of the species complex. We sampled fish identified morphologically as M. cephalus along Vietnamese shores and characterized them using the sequence polymorphism of two mitochondrial genes, the cytochrome oxidase I and cytochrome b. This demonstrated that all three species described in the NW Pacific are present in both northern and southern Vietnamese waters. Although the difference in species abundance reflects those observed in the NW Pacific, no phylogeographic pattern was revealed. In addition, no population structure was observed whatever the species or the distribution range considered, which indicates a significant level of gene flow that maintains genetic homogeneity of the three species. It is also conceivable that each species experienced a recent population expansion from a single ancestral population. Finally we suggest that if the cold waters of the NW Pacific present a physiologic challenge leading to the almost parapatric distribution of the three species, then it is likely that the warm surface temperatures of the South China Sea negate this barrier.

Vietnam is an important crossroads within Mainland Southeast Asia (MSEA) and a gateway to Island Southeast Asia, and as such exhibits high levels of ethnolinguistic diversity. However, comparatively few studies have been undertaken of the genetic diversity of Vietnamese populations. In order to gain comprehensive insights into MSEA mtDNA phylogeography, we sequenced 609 complete mtDNA genomes from individuals belonging to five language families (Austroasiatic, Tai-Kadai, Hmong-Mien, Sino-Tibetan and Austronesian) and analyzed them in comparison with sequences from other MSEA countries and Taiwan. Within Vietnam, we identified 399 haplotypes belonging to 135 haplogroups; among the five language families, the sequences from Austronesian groups differ the most from the other groups. Phylogenetic analysis revealed 111 novel Vietnamese mtDNA lineages. Bayesian estimates of coalescence times and associated 95% HPD for these show a peak of mtDNA diversification around 2.5–3 kya, which coincides with the Dong Son culture, and thus may be associated with the agriculturally-driven expansion of this culture. Networks of major MSEA haplogroups emphasize the overall distinctiveness of sequences from Taiwan, in keeping with previous studies that suggested at most a minor impact of the Austronesian expansion from Taiwan on MSEA. We also see evidence for population expansions across MSEA geographic regions and language families.

Deep CNN techniques have dramatically become the state of the art in image classification. However, applying high-capacity Deep CNN in medical image analysis has been impeded because of scarcity of labeled data. This study has two primary contributions: first, we propose a classification model to improve performance of classification of skin lesion using Deep CNN and Data Augmentation. Second, we demonstrate the use of image data augmentation for overcoming the problem of data limitation and examine the influence of different number of augmented samples on the performance of different classifiers. The proposed classification system is evaluated using the largest public skin lesion testing dataset, containing 600 testing images, and 6,162 training images. New state-of-the-art performance result is archived with AUC (89.2% vs. 87.4%), AP (73.9% vs. 71.5%), and ACC (89.0% vs. 87.2%). In additional, we explore the influence of each image augmentation on the three classifiers and observe that performance of each classifier is influenced differently by each augmentation and has better results comparing with traditional methods. Thus, it is suggested that the performance of skin cancer classification and medial image classification could be improved further by applying data augmentation.

International audience; We analyse a huge and very precise trace of contact data collected by a network of sensors during 6 months on the entire population of a rehabilitation hospital. We investigate both the topological structure of the average daily link stream of contacts in the hospital and the temporal structure of the evolution of these contacts hour by hour. Our main aims are to unveil striking properties of these two structures in the considered hospital, and to present a methodology that can be used for analysing any link stream where nodes are classified into groups.

International audience; This paper studies the robust finite-time Ho., control for a class of nonlinear systems with time-varying delay and disturbances via output feedback. Based on the Lyapunov functional method and a generalized Jensen integral inequality, novel delay-dependent conditions for the existence of output feedback controllers are established in terms of linear matrix inequalities (LMIs). The proposed conditions allow us to design the output feedback controllers which robustly stabilize the closed-loop system in the finite-time sense. An application to $H_\infty$ control of uncertain linear systems with interval time-varying delay is also given. A numerical example is given to illustrate the efficiency of the proposed method.