Influence of lunar semidiurnal tides on groundwater dynamics in estuarine aquifers

The influence of lunar semidiurnal tides on coastal groundwater aquifers has been conceptualized for decades. However, a thorough understanding of the impact of tides on groundwater dynamics due to the widely distributed waterways and heterogeneous sediments in estuarine aquifers, is still needed. This study shows the tidal impact on groundwater dynamics in the Pearl River estuary in southeast China through wavelet and time series analysis. The groundwater level and electrical conductivity (EC), as well as tidal levels, were monitored in several observation wells and tidal stations to determine how the estuarine groundwater levels respond to tidal forcing. The results show that the groundwater fluctuations have short periodicities of 0.51 and 1 day corresponding to major tidal constituents of M2 (semidiurnal) and K1 and O1 (diurnal) signals, respectively. The significant impacts decrease with increasing distance inland of the locations of the wells. Additionally, the coherence analysis displays a higher correlation between tides and groundwater levels for the spring tide than for the neap tide. The tidal influences on groundwater EC are weak compared to those on groundwater levels. In addition, when the tidal level increases, the EC decreases in wells located in the estuarine entrance. This is related to the high salinity of retained paleo-seawater in the strata lenses. A conceptual model is proposed to illustrate the complex groundwater flow dynamics. The model may provide useful insights into the understanding of similar systems located in geographically different coastal regions.© 2020 Springer. This is a post-peer-review, pre-copyedit version of an article published in Hydrogeology Journal. The final authenticated version is available online at: http://dx.doi.org/10.1007/s10040-020-02136-8fi=vertaisarvioitu|en=peerReviewed

A Review of Bambusicolous Ascomycetes

Bamboo with more than 1500 species is a giant grass and was distributed worldwide. Their culms and leaves are inhabited by abundant microfungi. A documentary investigation points out that more than 1300 fungi including 150 basidiomycetes and 800 ascomycetous species with 240 hyphomycetous taxa and 110 coelomycetous taxa are associated with bamboo. Ascomycetes are the largest group with totally 1150 species. Families Xylariaceae and Hypocreaceae, which are most represented, have 74 species and 63 species in 18 and 14 genera, respectively, known from bamboo. The genus Phyllachora with a maximum number of species (22) occurs on bamboo, followed by Nectria (21) and Hypoxylon (20). The most represented host genera Bambusa, Phyllostachys, and Sasa are associated by 268, 186, and 105 fungal species, respectively. The brief review of major morphology and phylogeny of bambusicolous ascomycetes is provided, as well as research prospects

Wireless Deep Video Semantic Transmission

In this paper, we design a new class of high-efficiency deep joint source-channel coding methods to achieve end-to-end video transmission over wireless channels. The proposed methods exploit nonlinear transform and conditional coding architecture to adaptively extract semantic features across video frames, and transmit semantic feature domain representations over wireless channels via deep joint source-channel coding. Our framework is collected under the name deep video semantic transmission (DVST). In particular, benefiting from the strong temporal prior provided by the feature domain context, the learned nonlinear transform function becomes temporally adaptive, resulting in a richer and more accurate entropy model guiding the transmission of current frame. Accordingly, a novel rate adaptive transmission mechanism is developed to customize deep joint source-channel coding for video sources. It learns to allocate the limited channel bandwidth within and among video frames to maximize the overall transmission performance. The whole DVST design is formulated as an optimization problem whose goal is to minimize the end-to-end transmission rate-distortion performance under perceptual quality metrics or machine vision task performance metrics. Across standard video source test sequences and various communication scenarios, experiments show that our DVST can generally surpass traditional wireless video coded transmission schemes. The proposed DVST framework can well support future semantic communications due to its video content-aware and machine vision task integration abilities.Comment: published in IEEE JSA

Variations in protein concentration and nitrogen sources in different positions of grain in wheat

The distribution patterns of total protein and protein components in different layers of wheat grain were investigated using the pearling technique, and the sources of different protein components and pearling fractions were identified using (15)N isotope tracing methods. It was found that N absorbed from jointing to anthesis (JA) and remobilized to the grain after anthesis was the principal source of grain N, especially in the outer layer. For albumin and globulin, the amount of N absorbed during different stages all showed a decreasing trend from the surface layer to the center part. Whereas, for globulin and glutenin, the N absorbed after anthesis accounted for the main part indicating that for storage protein, the utilization of N assimilated after anthesis is greater than that of the stored N assimilated before anthesis. It is concluded that manipulation of the N application rate during different growth stages could be an effective approach to modulate the distribution of protein fractions in pearled grains for specific end-uses

Mechano-stimulated modifications in the chloroplast antioxidant system and proteome changes are associated with cold response in wheat

BACKGROUND: Mechanical wounding can cause morphological and developmental changes in plants, which may affect the responses to abiotic stresses. However, the mechano-stimulation triggered regulation network remains elusive. Here, the mechano-stimulation was applied at two different times during the growth period of wheat before exposing the plants to cold stress (5.6 °C lower temperature than the ambient temperature, viz., 5.0 °C) at the jointing stage. RESULTS: Results showed that mechano-stimulation at the Zadoks growth stage 26 activated the antioxidant system, and substantially, maintained the homeostasis of reactive oxygen species. In turn, the stimulation improved the electron transport and photosynthetic rate of wheat plants exposed to cold stress at the jointing stage. Proteomic and transcriptional analyses revealed that the oxidative stress defense, ATP synthesis, and photosynthesis-related proteins and genes were similarly modulated by mechano-stimulation and the cold stress. CONCLUSIONS: It was concluded that mechano-stimulated modifications of the chloroplast antioxidant system and proteome changes are related to cold tolerance in wheat. The findings might provide deeper insights into roles of reactive oxygen species in mechano-stimulated cold tolerance of photosynthetic apparatus, and be helpful to explore novel approaches to mitigate the impacts of low temperature occurring at critical developmental stages. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12870-015-0610-6) contains supplementary material, which is available to authorized users

Bioactive compounds from Rumex plants

Two new naphthalene acylglucosides, rumexneposides A (1) and B (2), together with 12 known compounds (3-14), were isolated from the roots of Rumex nepalensis. Their structures were established by chemical and spectroscopic methods. The biological activities of compounds 1-14 as well as an additional 11 compounds previously isolated from R. nepalensis and Rumex hastatus (15–25) were evaluated against Mycobacterium tuberculosis, para-aminobenzoic acid (pAba) pathway, and a panel of human cancer cell lines. The results showed that compound 15 was the most active against M. tuberculosis with an MIC value of 2.85 mM similar to that of isoniazid. Compound 5 could inhibit pAba synthetic pathway with an MIC value of 12.6 mM, comparable to that of positive control abyssomicin C, representing a new example of the rare pAba pathway inhibitors

Green synthesis and biological evaluation of novel 5-fluorouracil derivatives as potent anticancer agents

This study reports the formation of 5-FU co-crystals with four different pharmacologically safe co-formers; Urea, Thiourea, Acetanilide and Aspirin using methanol as a solvent. Two fabrication schemes were followed i.e., solid-state grinding protocol, in which API and co-formers were mixed through vigorous grinding while in the other method separate solutions of both the components were made and mixed together. The adopted approaches offer easy fabrication protocols, no temperature maintenance requirements, no need of expensive solvents, hardly available apparatus, isolation and purification of the desired products. In addition, there is no byproducts formation, In fact, a phenomenon embracing the requirements of green synthesis. Through FTIR analysis; for API the Nsingle bondH absorption frequency was recorded at 3409.02 cm−1 and that of single bondCdouble bondO was observed at 1647.77 cm−1. These characteristics peaks of 5-FU were significantly shifted and recorded at 3499.40 cm−1 and 1649.62 cm−1 for 5-FU-Ac (3B) and 3496.39 cm−1 and 1659.30 cm−1 for 5-FU-As (4B) co-crystals for Nsingle bondH and single bondCdouble bondO groups respectively. The structural differences between API and co-crystals were further confirmed through PXRD analysis. The characteristic peak of 5-FU at 2θ = 28.79918o was significantly shifted in the graphs of co-crystals not only in position but also with respect to intensity and FWHM values. In addition, new peaks were also recorded in all the spectra of co-formers confirming the structural differences between API and co-formers. In addition, percent growth inhibition was also observed by all the co-crystals through MTT assay against HCT 116 colorectal cell lines in vitro. At four different concentrations; 25, 50, 100 and 200 µg/mL, slightly different trends of the effectiveness of API and co-crystals were observed. However; among all the co-crystal forms, 5-FU-thiourea co-crystals obtained through solution method (2B) proved to be the most effective growth inhibitor at all the four above mentioned concentrations