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Recently, the biologically inspired intelligent artificial visual neural system has aroused enormous interest. However, there are still significant obstacles in pursuing large-scale parallel and efficient visual memory and recognition. In this study, we demonstrate a 28 × 28 synaptic devices array for the artificial visual neuromorphic system, within the size of 0.7 × 0.7 cm2, which integrates sensing, memory, and processing functions. The highly uniform floating-gate synaptic transistors array were constructed by the wafer-scale grown monolayer molybdenum disulfide with Au nanoparticles (NPs) acting as the electrons capture layers. Various synaptic plasticity behaviors have been achieved owing to the switchable electronic storage performance. The excellent optical/electrical coordination capabilities were implemented by paralleled processing both the optical and electrical signals the synaptic array of 784 devices, enabling to realize the badges and letters writing and erasing process. Finally, the established artificial visual convolutional neural network (CNN) through optical/electrical signal modulation can reach the high digit recognition accuracy of 96.5%. Therefore, our results provide a feasible route for future large-scale integrated artificial visual neuromorphic system. [ABSTRACT FROM AUTHOR]

Key message: LeBAHD56is preferentially expressed in tissues where shikonin and its derivatives are biosynthesized, and it confers shikonin acylation in vivo. Two WRKY transcriptional factors might regulateLeBAHD56’sexpression. Shikonin and its derivatives, found in the roots of Lithospermum erythrorhizon, have extensive application in the field of medicine, cosmetics, and other industries. Prior research has demonstrated that LeBAHD1(LeSAT1) is responsible for the biochemical process of shikonin acylation both in vitro and in vivo. However, with the exception of its documented in vitro biochemical function, there is no in vivo genetic evidence supporting the acylation function of the highly homologous gene of LeSAT1, LeBAHD56(LeSAT2), apart from its reported role. Here, we validated the critical acylation function of LeBAHD56 for shikonin using overexpression (OE) and CRISPR/Cas9-based knockout (KO) strategies. The results showed that the OE lines had a significantly higher ratio of acetylshikonin, isobutyrylshikonin or isovalerylshikonin to shikonin than the control. In contrast, the KO lines had a significantly lower ratio of acetylshikonin, isobutyrylshikonin or isovalerylshikonin to shikonin than controls. As for its detailed expression patterns, we found that LeBAHD56 is preferentially expressed in roots and callus cells, which are the biosynthesis sites for shikonin and its derivatives. In addition, we anticipated that a wide range of putative transcription factors might control its transcription and verified the direct binding of two crucial WRKY members to the LeBAHD56 promoter’s W-box. Our results not only confirmed the in vivo function of LeBAHD56 in shikonin acylation, but also shed light on its transcriptional regulation. [ABSTRACT FROM AUTHOR]

Region-specific gut spheroids are precursors for gastrointestinal and pulmonary organoids that hold great promise for fundamental studies and translations. However, efficient production of gut spheroids remains challenging due to a lack of control and mechanistic understanding of gut spheroid morphogenesis. Here, we report an efficient biomaterial system, termed micropatterned gut spheroid generator (μGSG), to generate gut spheroids from human pluripotent stem cells through mechanically enhanced tissue morphogenesis. We show that μGSG enhances the biogenesis of gut spheroids independent of micropattern shape and size; instead, mechanically enforced cell multilayering and crowding is demonstrated as a general, geometry-insensitive mechanism that is necessary and sufficient for promoting spheroid formation. Combining experimental findings and an active-phase-field morphomechanics theory, our study further reveals an instability-driven mechanism and a mechanosensitive phase diagram governing spheroid pearling and fission in μGSG. This work unveils mechanobiological paradigms based on tissue architecture and surface tension for controlling tissue morphogenesis and advancing organoid technology. Understanding and controlling morphogenesis is vital for biology and organoid technology. Here, the authors report an efficient biomechanical system to generate gut spheroids, and reveal instability-driven morphogenetic transitions with computational models. [ABSTRACT FROM AUTHOR]

Microrobots have garnered tremendous attention due to their small size, flexible movement, and potential for various in situ treatments. However, functional modification of microrobots has become crucial for their interaction with the environment, except for precise motion control. Here, a novel artificial intelligence (AI) microrobot is designed that can respond to changes in the external environment without an onboard energy supply and transmit signals wirelessly in real time. The AI microrobot can cooperate with external electromagnetic imaging equipment and enhance the local radiofrequency (RF) magnetic field to achieve a large penetration sensing depth and a high spatial resolution. The working ranges are determined by the structure of the sensor circuit, and the corresponding enhancement effect can be modulated by the conductivity and permittivity of the surrounding environment, reaching ~560 times at most. Under the control of an external magnetic field, the magnetic tail can actuate the microrobotic agent to move accurately, with great potential to realize in situ monitoring in different places in the human body, almost noninvasively, especially around potential diseases, which is of great significance for early disease discovery and accurate diagnosis. In addition, the compatible fabrication process can produce swarms of functional microrobots. The findings highlight the feasibility of the self-sensing AI microrobots for the development of in situ diagnosis or even treatment according to sensing signals. [ABSTRACT FROM AUTHOR]

Due to the need for a higher safety level, autonomous marine surface vehicles have been increasingly applied for various applications in recent years. Nonlinear model predictive control (NMPC) has increasingly become a more preferred control technique. However, it has still limited use in industry due to its high computational load which is mainly caused by its complex Newton numerical method and Hessian matrix evaluations. In this study, we have developed a robust multistage NMPC algorithm to accurately control an autonomous marine surface vehicle when model uncertainties or environmental disturbances are present. The robust multistage NMPC is compared with the standard NMPC and perfect information NMPC. Advanced symbolic computation approach has been used to implement all three NMPC programs, where the complex gradient vector, Hessian matrix, and nonlinear dynamic optimization problem are derived analytically and evaluated with machine accuracy. The simulation results reveal that the robust multistage NMPC approach is successfully able to better control an autonomous marine surface vehicle than the standard NMPC method, and impressively is almost as good as the perfect information NMPC when model uncertainties or environmental disturbances are present. Furthermore, it has been demonstrated that the robust NMPC is also very effective for a large scaled-up prototype system. [ABSTRACT FROM AUTHOR]

Nonylphenol (NP) is widely used in the chemical industry; it accumulates in organisms through environmental contamination and causes learning memory impairment. Nicotinamide mononucleotide (NMN) has been found to have a positive effect on the treatment of central nervous-related diseases. This study aimed to investigate the protective effect of NMN on NP-induced learning memory-related impairment in vitro and to further identify the underlying mechanisms. The results showed that NP induced oxidative stress and impaired the cholinergic system, 5-HT system in PC-12 cells. NMN alleviated NP-induced learning and memory impairment at the molecular level through alleviating oxidative stress and protective effects on the 5-HT system and cholinergic system. The 50 μM NP group significantly reduced the NAD+ content, and the relative expression of SIRT1, PGC-1α, Nrf2, MAOA, BDNF, and p-TrkB were significantly downregulated. Co-treatment of NMN with NP significantly reduced oxidative stress, improved the homeostasis of 5-HT and cholinergic system, enhanced the intracellular NAD+ content, and significantly upregulated the expression of SIRT1 pathway proteins. SIRT1 inhibitors reduced the expression of SIRT1 pathway-related proteins, which implied the impairment of learning and memory by NP and the protective effect of NMN might be achieved through the SIRT1-mediated PGC-1α/MAOA/BDNF signaling pathway. Overall, this study not only help us to understand the toxic mechanism of NP on learning memory impairment in vitro, but also have important reference significance to further explore the health care value of NMN and promote the development of related functional foods. [ABSTRACT FROM AUTHOR]

The rapid rise of tourism in the karst regions has promoted the development of the local economy by relying on the unique landforms and landscapes. However, tourism development is often accompanied by land use changes and has an impact on the ecological environment. Exploring the coupling relationship between "tourism development-land use-landscape pattern" is very important for ecologically fragile karst areas. Taking the Yulong River Basin as an example, this research applied 3S technology, spatial analysis based on POIs, and regression analysis to the following: (1) identifying the process and effects of land use change, (2) determining the spatial pattern of tourism land and its correlation with land use change, (3) determining the characteristics and impacts of landscape pattern evolution. As the results suggested: (1) The significant expansion of construction land occupies a large amount of farmland, there is a balanced relationship between farmland and forest land for mutual conversion. (2) The aggregation of tourist land is affected by the trend of tourist behavior and the distribution of scenic spots. There is a significant moderate positive correlation between tourism land and construction land. (3) With the land use change, landscape heterogeneity has improved, but landscape fragmentation is serious and landscape connectivity is reduced. This research provides new evidences for the effect of the rapid development of tourism on land use change and ecological environment and as a reference to future orderly and moderate land development and ecological sustainability in karst regions. [ABSTRACT FROM AUTHOR]

Synapses are essential for the transmission of neural signals. Synaptic plasticity allows for changes in synaptic strength, enabling the brain to learn from experience. With the rapid development of neuromorphic electronics, tremendous efforts have been devoted to designing and fabricating electronic devices that can mimic synapse operating modes. This growing interest in the field will provide unprecedented opportunities for new hardware architectures for artificial intelligence. In this review, we focus on research of three-terminal artificial synapses based on two-dimensional (2D) materials regulated by electrical, optical and mechanical stimulation. In addition, we systematically summarize artificial synapse applications in various sensory systems, including bioplastic bionics, logical transformation, associative learning, image recognition, and multimodal pattern recognition. Finally, the current challenges and future perspectives involving integration, power consumption and functionality are outlined. [ABSTRACT FROM AUTHOR]

This study provides proof of concept of a colorimetric biosensor for influenza H1N1 virus assay based on the CRISPR/Cas13a system and hybridization chain reaction (HCR). Target RNA of influenza H1N1 virus activated the trans-cleavage activity of Cas13a, which cleaved the special RNA sequence (-UUU-) of the probe, further initiating HCR to copiously generate G-rich DNA. Abundant G-quadruplex/hemin was formed in the presence of hemin, thus catalyzing a colorimetric reaction. The colorimetric biosensor exhibited a linear relationship from 10 pM to 100 nM. The detection limit was 0.152 pM. The biosensor specificity was excellent. This new and sensitive detection method for influenza virus is a promising rapid influenza diagnostic test. [ABSTRACT FROM AUTHOR]

With the decline in fish resources worldwide, the ecological dominance and economic importance of crustaceans have obviously increased. Among crustacean species, mantis shrimps are increasingly dominant in many coastal waters of the world. In China, Oratosquilla oratoria is the most widely distributed and productive species of mantis shrimp, and its relative resource density is the highest in the Bohai Sea. In this study, we analysed the long-term and monthly population characteristics of O. oratoria in the Bohai Sea, including its relative resource density, body size and spatial distribution. The results showed that the relative resource density of O. oratoria in the Bohai Sea increased from 3.59 kg/h in 1982 to 14.48 kg/h in 2018, and the percentage of this species that serves as a fishery resource increased from 4.22% in 1982 to 35.27% in 2018, based on the mean relative resource density in May and August. The relative resource density of O. oratoria in the fishing moratorium season from May to August was significantly higher than that in the other months of fishing season, and the relative resource density decreased rapidly after the fishing moratorium ended. The relative resource density of O. oratoria was the highest in summer (August), followed by in autumn (October) and spring (May), and it was the lowest in winter (January). The relative resource density of O. oratoria in the western Bohai Sea was higher than that in the eastern Bohai Sea. The mean body weight of O. oratoria in the Bohai Sea decreased from 21.95 g in 1982 to 14.34 g in 2018, based on the mean body weight in May and August. The body size of O. oratoria in the fishing moratorium season was significantly higher than that in the fishing season, and the body size decreased rapidly after the fishing moratorium ended. Overall, in the context of declining resources of most fishery species, the relative resource density of O. oratoria increased due to its hardiness and adaptability, and its body size decreased under intensive fishing over the past 30 years. The fishing moratorium system had a great influence on the population dynamics of O. oratoria in terms of the relative resource density and body size in the Bohai Sea. [ABSTRACT FROM AUTHOR]

Nonlinear model predictive control (NMPC) has become a preferred option particularly for controlling a strongly nonlinear system due to an increase in the availability of powerful cheap computing resources in recent years. However, there are still some hurdles to widely apply the NMPC algorithm for fast nonlinear dynamic systems. One of the primary challenges is how to quickly solve a set of nonlinear differential model equations and a nonlinear dynamic optimization problem in real time. A large portion of the computational problems arises from gradient vector and Hessian matrix derivations and evaluations. In this paper, the problem has been handled using an advanced symbolic computation tool called SymPy. With the symbolic computation, the complex gradient vector, Hessian matrix, and nonlinear dynamic optimization problem are derived analytically and evaluated with machine accuracy. As the rising need for a higher safety level, autonomous marine surface vehicles have been vastly used for various applications in recent years. It is known that model-free methods such as proportional-integral-derivative and nonlinear sliding mode controls are not sufficient to provide a robust control for a highly nonlinear surface vehicles. In this paper, the developed NMPC algorithm has been adopted to solve the two-dimensional trajectory tracking problem for an autonomous marine surface vehicle. [ABSTRACT FROM AUTHOR]

Purpose: Clay-humic substance complexes play a major role in controlling the mobility of elements and colloids in natural soils. The purpose of the present study is to explore the different reaction mechanisms induced by cations on the humic acid (HA) and montmorillonite (Mt) heteroaggregation and to analyze the binding mechanism of HA-Mt. Materials and methods: HA is extracted from soil and colloidal Mt are prepared as K+-saturated. The aggregation kinetics of HA-Mt composite nanoparticles in Ca(NO3)2, Mg(NO3)2, and Cu(NO3)2 solutions were detected by dynamic light scattering. Furthermore, FT-IR spectroscopy was used to characterize the reactive sites involved in interaction with the metal ions. Results and discussion: The results revealed that the order of reaction of these three metal cations with the HA-Mt composite was Cu2+ > Ca2+ > Mg2+, as evident from the total average aggregation rate, critical coagulation concentration, and activation energy. The heteroaggregation process was sensitive to the 1% mass percentage of HA; however, more HA (4% mass percentage) did not significantly affect this process compared with 1% HA. Higher cation concentration and higher HA content (10% mass percentage) were two necessary conditions for promoting HA-Mt heteroaggregation. The vibration peak intensities of the carboxyl group C-O bonds and hydroxyl group O-H bonds of HA were affected by the formation of coordinate bonds with different metal ions. Conclusions: Metal cations were preferentially complexed by the carboxyl groups of HA, and due to its polarization-induced and electric field–enhanced oxidizing properties, Cu2+ has the strongest aggregation ability for HA-Mt, followed by Ca2+ and Mg2+. The HA-Mt heteroaggregation is partially reversible by adjusting electrostatic repulsion. The results of this study improve our understanding of the roles of cations and HA in clay-humic substance interactions. [ABSTRACT FROM AUTHOR]

Although bacterioplankton play an important role in aquatic ecosystems, less is known about bacterioplankton assemblages from subtropical karst reservoirs of southwestern China with contrasting trophic status. Here, 16S rRNA gene next-generation sequencing coupled with water chemistry analysis was applied to compare the bacterioplankton communities from a light eutrophic reservoir, DL Reservoir, and a mesotrophic reservoir, WL Reservoir, in subtropical karst area of southwestern China. Our findings indicated that Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, Cyanobacteria and Verrucomicrobia dominated bacterioplankton community with contrasting relative frequency in the two subtropical karst reservoirs. Proteobacteria and Bacteroidetes were the core communities, which played important roles in karst biogeochemical cycles. Though WT, TN and DOC play the decisive role in assembling karst aquatic bacterioplankton, trophic status exerted significantly negative direct effects on bacterioplankton community composition and alpha diversity. Due to contrasting trophic status in the two reservoirs, the dominant taxa such as Enterobacter, Clostridium sensu stricto, Candidatus Methylacidiphilum and Flavobacteriia, that harbor potential functions as valuable and natural indicators of karst water health status, differed in DL Reservoir and WL Reservoir. [ABSTRACT FROM AUTHOR]

A point-of-care (POC) immunoassay was established for the sensitive and rapid detection of pathogenic Escherichia coli O157:H7, using magnetic Fe3O4 organic-inorganic composites (Ab@Fe3O4) for immunomagnetic separation, nanozyme platinum nanoparticle (PtNp) organic-inorganic composites (Ap@PtNp) for signal amplification, and thermometer readings. Antibodies and Fe3O4 were incubated in Cu2+ phosphate buffer to synthesize the magnetic composite Ab@Fe3O4 with antibodies, to specifically capture E. coli O157:H7. Antimicrobial peptides and PtNp were incubated in Cu2+ phosphate buffer to synthesize the signal composites Ap@PtNp with antimicrobial peptides (magainin I), recognizing and labeling E. coli O157:H7. In the presence of E. coli O157:H7, magnetic microcomposites targeted bacteria and signal microcomposites to form the sandwich structure: Ab@Fe3O4-bacteria-Ap@PtNp for magnetic separation. Ap@PtNp of signal composites catalyzed H2O2 to generate thermo-signals (temperature rise), which were determined by a thermometer. This point-of-care bioassay detected E. coli O157:H7 in the linear range of 101–107 CFU mL−1 and with a detection limit of 14 CFU mL−1. [ABSTRACT FROM AUTHOR]

Key message: Catalytically active indica SSIIa allele in high amylose rice with down-regulated japonica SBEIIb can increase starch content and modify the starch structure and properties without changing its amylose content. Rice (Oryza sativa) genotypes with inactive starch synthase IIa (SSIIa) with recessive variants of starch branching enzyme IIb (SBEIIb) exhibit a range of alterations in grain phenotype, starch granule morphology, starch granule bound proteins, starch structure, and functional properties. However, the interactions between the two enzymes have not been thoroughly investigated yet. We analysed recombinant rice lines having down-regulated SBEIIb expression (SBEIIbDR) with either indica or japonica type SSIIa (SSIIaind or SSIIajap). In SBEIIbDR rice starch granules, the increased abundance of two protein bands (SSI and SSIIa) was found with eight additional protein bands not generally associated with starch granules. The amount of SSIIa was higher in SSIIaindSBEIIbDR than SSIIajapSBEIIbDR, which indicated that indica type SSIIa, possibly in the monomer form, was extensively involved in starch biosynthesis in the SBEIIbDR endosperm. Furthermore, SSIIaindSBEIIbDR grains had higher total starch content and higher starch swelling power than SSIIajapSBEIIbDR lines, but the amylopectin gelatinization temperatures and enthalpy and the apparent amylose content remained similar. In summary, this work suggests that SSIIaind can partly compensate for the alteration of starch synthesis resulting from the SBEIIb down-regulation in japonica background without reducing its amylose content. The study provides insight into the starch structural and textural improvements of high amylose starch. [ABSTRACT FROM AUTHOR]

Person re-identification is to identify a target person in different cameras with non-overlapping views. It is a challenging task due to various viewpoints of persons, diversified illuminations, and complicated environments. In addition, body parts are usually misaligned because of the less precise bounding boxes, which play a significant role in person re-identification, so it is crucial to make them aligned for better performance. In this paper, we propose a network to learn powerful features combining global features and local-alignment features for person re-identification. For each body part, instead of fixed horizontal partition, a key points detection network is adopted to locate body parts that contain more precise and distinctive information. Besides, a novel re-ranking approach is proposed to refine the rough initial rank list by exploiting the spatial-temporal information. Unlike most existing re-ranking based methods fine-tuning the rough initial rank list only by k-nearest neighbors and their k-reverse-nearest neighbors, our method exploits spatial-temporal information which can be easily stored in the name of images, so it can be implemented in any baseline to improve the performance. Experiments on the GRID, Market-1501, and DukeMTMC-reID are conducted to prove the effectiveness of our method. [ABSTRACT FROM AUTHOR]

A sandwich immunoassay was developed for determination of E. coli O157:H7. This is based on an antimicrobial peptide-mediated nanocomposite pair and uses a personal glucose meter as signal readout. The antimicrobial peptides, magainins I, and cecropin P1 were employed as recognition molecules for the nanocomposite pair, respectively. With a one-step process, copper phosphate nanocomposites embedded by magainins I and Fe3O4 were used as "capturing" probes for bacterial magnetic isolation, and calcium phosphate nanocomplexes composed of cecropin P1 and invertase were used as signal tags. After magnetic separation, the invertase of the signal tags hydrolyzed sucrose to glucose, thereby converting E. coli O157:H7 levels to glucose levels. This latter can be quantified by a personal glucose meter. Under optimal conditions, the concentration of E. coli O157:H7 can be determined in a linear range of 10 to 107 CFU·mL−1 with a detection limit of 10 CFU·mL−1. The method was successfully applied to the determination of E. coli O157:H7 in milk samples. [ABSTRACT FROM AUTHOR]

The waxy gene (Wx-1) encodes the granule-bound starch synthase (GBSSI or waxy protein, Wx), which is the key enzyme that catalyzes amylose synthesis in wheat. In this study, tetraploid wheat (Triticum turgidum durum L.) was mutagenized by ethyl methanesulfonate, and M2 populations of 3474 plants were generated. The Wx-A1 orWx-B1 null mutants were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The results of cloning showed that there was a single nucleotide polymorphism (SNP) of G1086A in Wx-A1 of line M2-219, which is predicted to generate a stop codon, thereby resulting in premature termination of the Wx-A1 protein. Two SNPs, G207A and G1122A, were detected in Wx-B1 of M2-504; the former results in the amino acid substitution from Serine to Asparagine, whereas the latter disrupts the production of the Wx-B1 protein. The Wx-A1 and the Wx-B1 null mutants were crossed; the lines with variable waxy proteins compositions were characterized. The loss of function involving the waxy protein has resulted in changes in starch properties in various lines. The line lacking both Wx-A1 and Wx-B1 had the lowest amylose content and highest onset and peak gelatinization temperature; the lack of Wx-B1 results in an increase in amylose content instead of loss of Wx-A1. In addition, the abundance of B-type starch granules significantly increased in the Wx null line. Because waxy proteins largely influence the flour quality, then the Waxy lines with lower amylose content would be useful in wheat quality breeding. [ABSTRACT FROM AUTHOR]

With the decline of fish stocks, the proportions of economically important invertebrates like crustaceans and cephalopods have increased in the Bohai Sea. The community structure and trophic level of economically important invertebrates were analyzed using the bottom trawl survey data collected by the Yellow Sea Fisheries Research Institute in the Bohai Sea in May and August of 1958–1959, 1982, 1992–1993, 2004, 2009 and 2015. A total of 37 species of economically important invertebrates, belonging to 5 orders, 24 families, were captured. The biomass densities of economically important invertebrates in the Bohai Sea displayed an overall downward trend from 1982 to 2015. Oratosquilla oratoria and Loligo spp. were the most dominant species in the past 30 years, the biomass proportion of O. oratoria increased gradually in both May and August from 1982 to 2015. Moreover, biodiversity indices of economically important invertebrates in the Bohai Sea appeared to decline from 1982 to 2004 and then increased in 2015. Similarly, the mean trophic level of economically important invertebrates declined from 1982 to 2004 and increased slightly in 2015. Overall, although the proportions of invertebrates have increased, the biomass densities in the Bohai Sea have displayed an overall downward trend from 1982 to 2015. The increases in the biodiversity and trophic level of economically important invertebrates after the 2000s, possibly benefit from stock enhancement projects implemented by governments at different levels and national fishery management measures such as the "double-control" of the total number and engine power of fishing vessels and summer moratorium of fishing. [ABSTRACT FROM AUTHOR]

In order to further improve the accuracy and application range of pipeline network leakage detection, this paper simulates the complex water distribution system to set up an experimental platform. On this basis, a leakage detection method using improved wavelet denoising and short time Fourier transform is proposed, which can be used to monitor the leakage of the pipeline network in real time. This method is compared with the six methods of Empirical Mode Decomposition (EMD), wavelet decomposition, Gauss model, recurrence plot, Wigner-Ville distribution (WVD) and Wigner-Hough transformation (WHT). The results show that this method can accurately diagnose the leakage of the pipeline network. This method is verified by the field measured pressure signals of other literature. It is concluded that this method is effectual for the leakage detection of the actual complex pipeline network. In order to test the universality of this method, it is also used to analyze the pressure signal of the heating pipeline network and the gas pipeline network. The results show that the method proposed in this paper is also applicable to other complex pipeline networks. [ABSTRACT FROM AUTHOR]

Key message: An EMS-induced single-base mutation at a splice site caused abnormal RNA splicing and resulted in the gene inactivation and the lack of Wx-A1 protein in a wheat EMS mutant line. An EMS-mutagenized population was generated using common wheat cv. SM126 consisting of 10,600 M2 plants. One Wx-A1 null mutant was identified through analyses of 390 grains produced from 130 M2 plants using electrophoresis analyses. The Wx-A1 sequences of parental line SM126 and M2-31 mutant were determined as 2781 bp, and there was only one SNP mutation between them. The SNP was a mutation from G to A at nucleotide sequence position 2168 bp (G2168A) downstream of the start codon which was located at the splicing site within the eighth intron. All 52 cDNA transcripts were found to be incorrectly spliced and can be summarized as five types of variations. The deletion of the exon and the exclusion of intron were structural features in abnormal splicing RNA. Together with the prediction of potential splice regulatory motifs, the mutation G2168A happened within the 5′ splice site of the eighth intron and destroyed the splice donor site from GU to AU, which may have brought about a barrier against correct RNA splice, and generated abnormal mRNA, which was the mechanism of the inactivation of Wx-A1 in M2-31. The lack of Wx-A1 has resulted in changes in starch properties in the M2-31 mutant, with the reduction in amylose and starch contents. The increased grains hardness was observed in M2-31, which may be related to the lower expression level of Pinb-D1 gene. As the waxy wheat foods have a lot of advantages, the null waxy genes will be widely applied in breeding waxy wheat for varied amylose contents. [ABSTRACT FROM AUTHOR]

In this study, we successfully expressed the active 1Ay subunit of Triticum urartu in barley by Agrobacterium-mediated transformation with a transformation efficiency of 19.9%. The results of SDS–PAGE revealed that the expressed proteins of 1Ay subunit were present at some grains of each of 46 original T0 plants, showing identical mobility to those of positive standards of T. urartu grain protein and bacteria expressional proteins. In the T2 generation, three homozygous lines, 2–28, 3–11, and 5–6, were identified. The results of scanning electron microscopy showed an increased amount of protein bodies in these transgenic lines. The main effects in the expression of the 1Ay subunits was a considerable increase in the glutenin content, but a decrease in the contents of gliadins while there were no effects in the contents of albumin, globulin and the total protein. We found that the gluten could not be washed out from the flour obtained from transgenic barley lines when using a Gluten index analyzer and a Farinograph indicating that the transgenic barley lines could not form dough. The lack of x-type HMW-GS and the reduction in number of subunit were inferred as the possible reasons for the inability to form gluten polymer. [ABSTRACT FROM AUTHOR]

Purpose: The transport or retention behaviors of colloids in bulk soil have been studied extensively. However, little is known about the influence of colloid retention on the properties of bulk soil.Materials and methods: With this aim, the variation of surface electrochemical properties of saturated porous quartz sands after retention of goethite colloids was investigated by comparing the difference in the zeta potentials of quartz grains, with or without the transport of colloids. And the zeta potentials of porous media were calculated from in situ streaming potential measurement.Results and discussion: Our results indicate that the retention of goethite colloids changed the surface electrochemical properties of porous media significantly. With increasing transport time, more goethite colloids deposited on the surface of quartz grains and changed the zeta potential of porous media. There was a higher content of goethite colloids on the surface of quartz grains after transport of goethite colloids and, correspondingly, a more obvious variation in the zeta potential of quartz grains, if the supporting electrolyte contained monovalent ions, as compared to higher valent ions. Calculations based on DLVO (Derjaguin-Landau-Verwey-Overbeek) theory indicated that the main factor influencing the deposition of goethite colloids was the electrostatic attraction force between goethite colloids and quartz sands. Under the effect of the electrostatic attraction force, the zeta potential of porous media was changed by the deposition of goethite colloids on the surface of quartz grains.Conclusions: These findings will provide a useful reference for the understanding of the effect of microparticles on the surface electrochemical properties of bulk soil during migration processes. [ABSTRACT FROM AUTHOR]

Strategies of plant N acquisition among coexisting species are critical for many aspects of ecosystems with differential uptake of various N forms as one of these strategies, but much debate still exists. In the present study, strategic N uptake of nitrate and ammonium by 30 dominant species were investigated over two post-agricultural succession sequences in a calcareous karst area, southeast China. Each sequence includes grassland, shrubland, secondary forest and primary forest. Proportional contribution of nitrate and ammonium to plant N was estimated using isotopic mixing calculation. N uptake preference for the two N forms was assessed by comparing assimilation and availability of the N forms. The proportional contribution to plant N was much greater for nitrate than ammonium for the investigated species except three species (Monochoria vaginalis, Boehmeria dolichostachya and Miscanthus floridulus) for which the difference was not significant. Correlation analysis revealed that the contribution to plant N by a particular N form was linearly and positively related to its concentrations in soil. The proportional contribution to plant N by nitrate and ammonium increased logarithmically and decreased exponentially, respectively, as soil nitrate to ammonium ratio increased. N form uptake preference varied according to communities, but was consistent for the coexisting species within each community. The results indicate that the coexisting species share a similar strategy in their uptake of nitrate and ammonium during post-agricultural succession in the calcareous karst region, southwest China. [ABSTRACT FROM AUTHOR]

To gain a better understanding of the biological effect on the water-gas-carbonate interaction, 15 sample plots from five ecotypes (grass land, ecological demonstration, artificial forest, tree-shrub, and forest community) in three experimental sites of SW China due to the absence of time-series succession ecotypes at the same karst site were selected to discuss the relationship between soil microbial populations, carbonic anhydrase (CA) and limestone dissolution rate. The results show that the soil microbial populations and soil CA activities within different ecotypes have the significantly positive correlation ( r = 0.968), which vary significantly and tend to decrease along the ecological succession process. In view of moist character and water-holding capacity in the evergreen forest, which can fleetly participate in water-gas-carbonate interaction, the limestone dissolution rate is not matching to the total microbial population and CA activity in forest community. If the ecotype for forest community was removed, the correlative coefficient between CA and the limestone dissolution rate is 0.950, the correlative coefficient between CA and total microbial population is 0.999 and the correlative coefficient between limestone dissolution rate and total microbial population is 0.952. It can be inferred that soil CA secreted by the soil microorganisms has the important role to promote the production of bicarbonate ions which affects limestone dissolution rate. [ABSTRACT FROM AUTHOR]

To reveal the toxicity of multiple heavy metals from Pb-Zn tailing sands on soil microorganisms relating to soil organic C metabolic activity, 33 soil samples from different karst land use types (paddy field, corn field and citrus field) in Sidi village, Yangshuo, Guangxi, Southwest China were collected. The total concentrations of Pb, Zn, Cu and Cd, and diethylene triamine pentacetate acid (DTPA)-extractable Zn, Cu and Cd in the paddy field are higher than those in the corn and citrus field, which indicates that this area should not be used as farmland anymore according to the environmental quality evaluation standards for farmland of edible agricultural products of China (HJ/T332-2006). Due to the toxicity of multiple heavy metals from Pb-Zn tailing sands on soil microorganisms, the soil bacteria, actinomyces and fungi populations, soil microbial biomass C and N, and soil microbial quotient in the paddy field is lower than that in the corn and citrus field; however, soil organic C and total nitrogen (TN) in the paddy field are significantly higher than those in the citrus and corn field ( p < 0.05). Though C and C plants appear in the citrus field and corn field, respectively, the data of soil microorganisms, soil microbial biomass C and N, soil microbial quotient, soil organic C and TN have no significant difference in the citrus and corn fields ( p > 0.05), which indicates that the above results have no relation to plant photosynthesis. The carbon source utilization of microbial samples using Biolog EcoPlate assay shows that the average well color development, Shannon-Wiener diversity index ( H′ and E), Simpson index ( D) and McIntosh index ( U) in the paddy field are significantly lower than those in the citrus and corn fields ( p < 0.05). Our results revealed that soil microorganisms under the effect of toxic heavy metals from Pb-Zn tailing sands can decrease the mineralization rate of soil organic C, which in turn produces the accumulation of soil organic C in the severe Pb-Zn tailing sand-contaminated area. [ABSTRACT FROM AUTHOR]

Key message: The distribution of starch synthase I and starch branching enzyme IIb between the starch granule and amyloplast stroma plays an important role in determining endosperm amylose content of cereal grains. Abstract: Starch synthase IIa (SSIIa) catalyses the polymerisation of intermediate length glucan chains of amylopectin in the endosperm of cereals. Mutations of SSIIa genes in barley and wheat and inactive SSIIa variant in rice induce similar effects on the starch structure and the amylose content, but the severity of the phenotypes is different. This study compared the levels of transcripts and partitioning of proteins of starch synthase I (SSI) and starch branching enzyme IIb (SBEIIb) inside and outside the starch granules in the developing endosperms of these ssIIa mutants and inactive SSIIa variant. Pleiotropic effects on starch granule-bound proteins suggested that the different effects of SSIIa mutations on endosperm amylose content of barley, wheat and rice are determined by the distribution of SSI and SBEIIb between the starch granule and amyloplast stroma in cereals. Regulation of starch synthesis in ssIIa mutants and inactive SSIIa variant may be at post-translational level or the altered amylopectin structure deprives the affinity of SSI and SBEIIb to amylopectin. [ABSTRACT FROM AUTHOR]

The impacts of the Pb-Zn mine tailing dam incident on the degree of environmental response from soil properties were investigated in Sidi village, Guangxi Zhuang Autonomous Region, SW China, using statistical analysis, as well as canonical correspondence analysis (CCA). From the descriptive statistical analysis of soil properties in Sidi village, it can be seen that the topsoil pH ranged from 5.53 to 6.57, while the mean value was 5.74, which reflects the acidic and oxidized effect of the tailing sand. The total Pb in topsoil ranged from 569.50 to 6,423 mg kg, while the mean value was 1,852.33 mg kg, and the total Zn in topsoil ranged from 240.70 to 5,513 mg kg, while the mean value was 1,190.42 mg kg, which indicates that this area should not be as farmland anymore according to the environmental quality evaluation standards for farmland of edible agricultural products of China HJ/T332-2006. By analyzing the statistical analysis data and the CCA bioplot, the total Pb and the total Zn have the significant positive correlation coefficients ( r = 0.656, p < 0.01) and the angle between vectors of the total Pb and the total Zn is small, which confirms that the heavy metal contamination is mainly from the Pb-Zn intergrowth ore. Moreover, the soil microorganism and the total Pb-Zn are on the opposite quadrant in the CCA ordination diagram and the sensitivity of the soil microorganism to the total Pb-Zn in topsoil was observed in the order of bacteria < fungi < actinomyces. The soil enzyme was released by the soil microorganisms, therefore, the activities of invertase, urease, and alkaline phosphatase were inhibited into different degrees by the total Pb and the total Zn in topsoil. From the CCA biplot, their complex inwardness between the soil enzyme and the Pb-Zn contamination can be clearly and intuitively depicted. Then, the alkaline phosphatase activities have strongly positive correlation coefficients with the total Zn ( r = 0.451, p < 0.05) and the urease activities ( r = 0.394, p < 0.05). [ABSTRACT FROM AUTHOR]

Soil samples were collected on farmland in a lead-zinc mining area in the Karst region of Guangxi, China. The contamination of the soil by eight metals (Cd, Hg, As, Cu, Pb, Cr, Zn, Ni) was determined. Among all these metals, Cd is the most serious pollutant in this area. Zn, Hg as well asPb can also be measured at high levels, which may affect the crop production. All other metals contributed marginally to the overall soil contamination. Besides the evaluation of single metals, the Nemerow synthetic index indicated that the soil is not suitable for agricultural use. [ABSTRACT FROM AUTHOR]

The cellular prion protein (PrPC) is a highly conserved protein among mammals and is considered to have important cellular functions. Despite decades of intensive research, however, the physiological function of PrPC remains unclear. Sho (Shadoo, shadow of prion protein) and PrPC have similar N-terminals, which suggests that the two proteins share biological functions. Using truncation mutants of both proteins and yeast two-hybrid analysis, with validation by co-immunoprecipitation and surface plasmon resonance (SPR), we have identified an interaction between Sho 61–77 and PrPC 108–126 domains. This indicates that Sho may play a role in the physiological function of PrPC and prion pathogenesis. [ABSTRACT FROM AUTHOR]

Disproportionating enzyme or D-enzyme (EC 2.4.1.25) is an α-1,4 glucanotransferase which catalyses cleavage and transfer reactions involving α-1,4 linked glucans altering (disproportionating) the chain length distribution of pools of oligosaccharides. While D-enzyme has been well characterised in some plants, e.g. potato and Arabidopsis, very little is known about its abundance and function in cereals which constitute the major source of starch worldwide. To address this we have investigated D-enzyme in wheat ( Triticum aestivum). Two putative D-enzyme cDNA clones have been isolated from tissue-specific cDNA libraries. TaDPE1-e, from an endosperm cDNA library, encodes a putative polypeptide of 575 amino acid residues including a predicted transit peptide of 41 amino acids. The second cDNA clone, TaDPE1-l, from an Aegilops taushii leaf cDNA library, encodes a putative polypeptide of 579 amino acids including a predicted transit peptide of 45 amino acids. The mature polypeptides TaDPE1-e and TaDPE1-l were calculated to be 59 and 60 kDa, respectively, and had 96% identity. The putative polypeptides had significant identity with deduced D-enzyme sequences from corn and rice, and all the expected conserved residues were present. Protein analysis revealed that D-enzyme is present in the amyloplast of developing endosperm and in the germinating seeds. D-enzyme was partially purified from wheat endosperm and shown to exhibit disproportionating activity in vitro by cleaving maltotriose to produce glucose as well as being able to use maltoheptaose as the donor for the addition of glucans to the outer chains of glycogen and amylopectin. [ABSTRACT FROM AUTHOR]

The effectiveness of different promoters for use in Indica rice transformation was compared. Plasmids encoding the Escherichia coli uidA (gus) gene under the control of CaMV 35S, Emu, Act1 or Ubi1 promoters were delivered into cell suspension cultures by particle bombardment. Transient gene expression, 48 h after delivery, was greatest from plasmids utilising the constitutive promoters, Act1 and Ubi1. Gene expression in stably transformed tissue was examined by bombarding embryogenic Indica rice calli with a pUbi1-gas plasmid and a plasmid containing either the selectable marker gene, hph, which confers hygromycin resistance, or bar, which confers resistance to the herbicide phosphinothricin (BASTA) each under the control of the CaMV 35S, Emu, Act1 or the Ubi1 promoters. The bombarded calli were placed on the appropriate selection media and stained for GUS activity at 1 day, 3 weeks and 5 weeks after shooting. Callus bombarded with the pUbi1-hph or the pEmu-hph constructs gave a dramatic increase in the size of the GUS staining areas with time. No such increase in the size of GUS staining areas was observed in calli co-bombarded with pUbi1-gus and any of the bar containing constructs. Co-bombardment of calli with either the pEmu-hph or pUbi1-hph construct and a virus minor coat protein (cp) gene construct resulted in many fertile transgenic Indica rice plants, containing one to eight copies of both the hph and cp genes. These genes were stably inherited by the T1 generation. [ABSTRACT FROM AUTHOR]

The published version of this article, unfortunately, contained error. The authors are re-writing to express their sincere apology for a mistake that a mark “10-5, 10-4, 10-3, 10-2, 10-1 CFU•mL-1” in the legend of Fig. 2 was not corrected as “105, 104, 103, 102, 101 CFU•mL-1”. [ABSTRACT FROM AUTHOR]