Search

Background Rhizosphere fungi and endophytic fungi play key roles in plant growth and development; however, their role in the growth of Epimedium koreanum Nakai at different stages remains unclear. Here, we used the Illumina MiSeq system, a high-throughput sequencing technology, to study the endophytic fungi and rhizosphere microbiome of Korean Epimedium. Results Epimedium koreanum Nakai rhizosphere soil and leaves had highly diverse fungal communities during the growth process. The relative abundance of soil fungi in the rhizosphere stage was higher than that of leaf endophytic fungi in the early growth stage, but the overall abundance was basically equal. Sebacina is a significantly divergent fungal genera, and Sebacina sp. are present among leaf fungi species in the rhizosphere soil of Epimedium koreanum Nakai. Sebacina sp. can move to each other in rhizosphere soil fungi and leaf endophytes. VIF (variance inflation factor) analysis showed that soluble salt, whole nitrogen, alkaline lysis nitrogen, whole phosphorus, total potassium, and fast-acting potassium are useful environmental factors for rhizosphere soil and leaf endophytic fungi: potassium, total nitrogen, whole phosphorus, and three environmental factors were significantly and positively associated with the relative abundance of Sebacina sp. Conclusions (1) This study is the first to clarify the species diversity of fungi in Epimedium koreanum Nakai leaf and rhizosphere soil. (2) Different fungal communities of rhizosphere soil fungi and leaf endophytic fungi at different growth stages of Epimedium koreanum Nakai were examined. (3) Sebacina sp. can move to each other between rhizosphere soil fungi and leaf endophytic fungi. (4) Nitrogen, phosphorus and potassium elements in the environment have a significant positive effect on the relative abundance of Sebacina sp.

Intent-Driven Network (IDN) is a promising networking paradigm that makes network management autonomous, flexible, and scalable. IDN reduces the difficulty of network management by translating the declarative user intent to machine-executable policies. Although IDN brings considerable advantages to network management, there exist novel security policy management problems, such as security intent-aware policy conflict. Although there are already some conflict resolution schemes, they are less automated and more energy-consuming. We present a Quadruple-based Intent Conflict Resolution (QICR) engine to address the intent conflict in IDN in this paper. The QICR implements an intent conflict resolution scheme to convert potentially conflicting intents to conflict-free intents. We implement the QICR engine in a simulation platform and demonstrate the proposed conflict resolution scheme's effectiveness.

Foliage spatial distribution and morphological variation within crowns reflect the adjustment of a tree to acclimatise to different microenvironments within crowns and stands. They play important roles in the light use efficiency, carbon assimilation and photosynthesis capacity of the whole tree. In this study, leaf quantity and size at the tree and crown layer levels, and leaf morphology across crown layers, sectors and zones, from 18 trees were investigated in five-year-old Betula alnoides plantations with six planting densities. The results showed that the vertical distributions of leaf number, leaf area index, cumulative branch cross sectional area and leaf area and their ratios were skewed towards the upper crown layers, especially for high planting densities. There was a tendency for leaf size (leaf length, width, perimeter and area) and leaf dry mass to increase from lower to upper crown layer and also from the inner to outer crown zones. The leaf shape factor was larger, and the ratio of leaf length to width and specific leaf area were much smaller, for leaves in the outer and upper crown positions. Leaves in the southern and eastern sectors were smaller than those in the northern and western sectors, but leaf length to width ratio, leaf shape factor and specific leaf area did not differ significantly among four crown sectors. In addition, planting density had no significant effect on leaf related traits at the individual tree and crown layer levels, and leaf morphology also did not vary regularly with planting density, but the specific leaf area was significantly negatively correlated with planting density. However, the interactions between planting density and crown layer, crown sector and crown zone, and among planting density, crown layer and crown zone, were significant. The findings confirmed the acclimation of leaf distribution and morphology to different microenvironments, and provided baseline information for plantation management of B. alnoides and other valuable hardwood species in southern China and other regions with similar climate conditions.

Diamond solid-state devices are very attractive to electrically control the charge state of nitrogen-vacancy (NV) centers. In this work, p-type vertical diamond Schottky diodes (VDSDs) are introduced as a platform to electrically control the interconversion between the neutral charge NV (NV0) and negatively charged NV (NV−) centers. The photoluminescence of NV centers generated by ion implantation in VDSDs shows an increase in NV−zero phonon line (ZPL) and phonon sideband intensities with reverse voltage, whereas the NV0ZPL intensity decreases. Thus, NV centers embedded in VDSDs are converted into NV−under reverse bias voltage. Moreover, the optically detected magnetic resonance (ODMR) of NV−exhibits an increase in the ODMR contrast with reverse bias voltage and splitting of the resonance dips. Since no magnetic field is applied, the dip splitting in the ODMR spectrum is ascribed to the Stark effect induced by the interaction of NV−with the electric field existing within the depletion region of VDSDs.

Nearest neighbor mobile social network means that movers approaching in position communicate through their social sensors, which is called Proximity Mobile Social Network. Proximity Mobile Social Network can provide more social and business opportunities for users. To carry out disaster relief work in post-disaster environment, we need to collect incident information during the search process and report to the sink in time. Proximity Mobile Social Network provides flexible systems for emergency handling and disaster relief. Therefore, how to find a better data forwarding and routing strategy is the key problem of post-disaster rescue, and the research of user mobility model is the basis of the above problems. This article presents an Autonomy-Oriented Proximity Mobile Social Network modeling for emergency rescue in smart city, which simulates the network operating environment. First, we verify the performance of Autonomy-Oriented Proximity Mobile Social Network model in terms of self-organization, scale-free, aggregation, and community structure. Then, the rescue efficiency is discussed through the coverage of mobile sensors. Finally, performance of the routing strategy based on Autonomy-Oriented Proximity Mobile Social Network model is analyzed, and the effectiveness of the method is proved.

To date only one species of the genus Vatica Linn. (Dipterocarpaceae) has been identified, and a subspecies and three varieties have been reported on Hainan Island, China. However, it remained controversial whether the species was Vatica mangachapoi or a new species Vatica hainanensis, and whether the subspecies or varieties are taxonomically valid. We evaluated here morphometric variations of 133 trees collected from nine populations and herbarium specimens of Vatica spp. using 16 traits of leaf and fruit. Among these, leaf traits varied more within and among populations than did fruit traits. Four traits of ratios were more stable than directly-measured traits within and among populations. The ranges of lamina length, lamina width and height of maximum lamina width point were the greatest among the 16 traits, while number of lateral veins varied least among the 12 directly-measured traits. Measurements from all 9 populations overlapped for each morphological trait, and variation of each trait was continuous among both individuals and populations. The range of variation did not distinguish any specimen from V. mangachapoi as described in the flora of Southeast Asia. By cluster analysis, individuals of each population as well as specimens of each variety formed no distinct clusters. The published varieties thus were characterized by no distinguishing variations in comparison with the nine sampled populations. In conclusion, the new species V. hainanensis as well as the subspecies and varieties were not supported by our comparisons, and only V. mangachapoi without any subspecies or varieties occurs on Hainan Island, China.

Betula alnoides is a fast-growing hardwood species grown in large plantations in Southeast Asia and South China. Nitrogen requirements for producing robust seedlings, growth and nutrient dynamics were investigated using exponential fertilization treatments. Root collar diameter, height, dry mass and nutrient contents of seedlings increased exponentially in all fertilization treatments as time progressed. Moreover, with water soluble fertilizer (Plant Products plus microelements N–P2O5–K2O: 20–20–20), 300 mg N seedling−1 was adequate. Vector analysis revealed that P was the most responsive nutrient element, followed by N and K. Dilutions of N and K were evident in the plants without N addition, which induced initial P sufficiency and then luxury consumption probably due to the antagonistic interaction between N and P. However, deficiencies of N, P and K were mostly observed in all exponential regimes during the experiment because seedling growth rate exceeded nutrient uptake rate, inferring that further study on improving the nutrient uptake efficiency is needed. Analysis of relationships among nutrient supply, dry mass, N content and N concentration demonstrated that 100–400 mg N seedling−1 induced sufficiency to luxury consumption of nitrogen without significant change in dry mass, and 400 mg N seedling−1 is recommended to apply for nutrient loading of seedlings before outplanting. The findings will help improve seedling quality and enhance the production of robust seedlings for plantation forestry of this species.

Both crown and branch characteristics greatly affect tree growth and timber quality, and their development is closely related to planting density (PD). Here crown and branch attributes of Betula al...

Spatial distribution and season-induced variations in foliar nutrients of tree crowns play key roles in growth, and nutrient retranslocation and resorption from leaves are important mechanisms for trees to cope with sites of diversified fertility. Seasonal dynamics and spatial patterns of foliar macronutrients (Nitrogen (N), Phosphorus (P) and Potassium (K)) as well as nutrient retranslocation and resorption in a series of crown layers were examined in 5-year-old Betula alnoides plantations using a spacing trial (2500 (2 m × 2 m, spacing), 1667 (2 m × 3 m), 1250 (2 m × 4 m), 1111 (3 m × 3 m), 833 (3 m × 4 m) and 625 (4 m × 4 m) stems·ha−1) in south China. Significant effects of planting density on foliar nutrient concentrations and nutrient retranslocation and resorption were absent during a whole seasonal cycle or in each season. Both foliar total P and K concentrations increased significantly with increasing crown depth, whereas an obvious trend was not observed for foliar total N concentration. The season with the lowest foliar nutrient concentration varied with the elements, i.e. summer (Jul) for N, winter (Jan) for P and spring (Apr) for K, whereas the highest was observed in autumn (Oct) for all these macronutrient elements. Among crown layers, differences in nutrient concentrations were much lower in the high growth seasons from October to April than those in other seasons. There were significant differences among crown layers in N and P retranslocation efficiency rather than in nutrient resorption efficiency. Significant differences were absent in both retranslocation and resorption efficiencies of K. The highest nutrient retranslocation efficiency was found in the crown layer 2–3 m above ground level for N and 3–4 m for P. The absence of considerable differences among spacing treatments and crown layers mentioned above might be due to the weak early intra-specific competition induced by planting density, soil fertility or fertilization and nutrient demands of this species. These findings could provide suggestions for implementing proper pruning treatments, improving fertilization regimes and other related forest managements for B. alnoides and even other valuable timber species in the tropical and warm sub-tropical regions.

Knot-related defects are important criteria for timber grading of valuable tree species. Clear-wood production through pruning has been an important issue in silviculture and forest management. In this study, knot attributes, branch occlusion and discoloration under natural and artificial pruning were investigated in a 10-year-old Betula alnoides plantation to determine the effectiveness of artificial pruning in mitigating knot-related defects. The dataset contained 270 occluded branches sampled from 30 artificially-pruned trees and 284 from 30 trees under natural pruning. Linear and generalized linear mixed-effect models were constructed to reveal the differences in factors influencing branch occlusion, knot size, and discoloration between natural and artificial pruning treatments. The mixed-effect models indicated that the most important factor in predicting branch occlusion time, dead knot radius, total knot radius and discoloration length was branch diameter for artificial pruning and dead branch stub length for natural pruning. The dead branch stub length was also closely and positively correlated with branch diameter under natural pruning. Branch occlusion time was negatively correlated with stem diameter growth rate during the period of branch occlusion while discoloration length was positively correlated with branch occlusion time for both treatments. In addition, acute branch insertion angle increased the size of dead knot and discoloration. It was concluded that artificial pruning promotes faster branch occlusion, reduces knot sizes and does not lead to stem discolorations, and should hence be applied in the plantation management of this species.

We studied the formation of heartwood in Erythrophleum fordii Oliv., an endangered rosewood species, by cross-section analysis on 52 stumps aged 28–57 years and arbitrarily sampled from natural forests in South China. Width and area of heartwood were positively correlated with age and xylem width (XW), and were independent of annual radial growth. The proportions of heartwood and sapwood areas were equal at about 40 years. The heartwood formation process was simulated by linear regression of age and XW.

Albumins, globulins, gliadins, and glutenins were isolated from wheat flour and the effects of those proteins on retrogradation of wheat starch were investigated. The results showed that only glutenins retarded retrogradation of wheat starch and other 3 proteins promoted it. The results of IR spectra proved that no S-S linkage formed during retrogradation of wheat starch blended with wheat proteins. Combination of wheat starch and globulins or gliadins through glucosidic bonds hindered the hydrolysis of wheat starch by α-amylase. The melting peak temperatures of retrograded wheat starch attached to different proteins were 128.46, 126.14, 132.03, 121.65, and 134.84 °C for the control with no protein, albumins, glutenins, globulins, gliadins groups, respectively, and there was no second melting temperature for albumins group. Interaction of wheat proteins and starch in retrograded wheat starch greatly decreased the endothermic enthalpy (△H) of retrograded wheat starch. Retrograded wheat starch bound to gliadins might be a new kind of resistant starch based on glycosidic bond between starch and protein.

Branch development in the lower part of stem is critical to both early stem growth and wood quality of the most valuable section of tree, and its regulation through planting density has always been greatly concerned. Here the effect of planting density on branch development was examined in a five-year-old plantation of Betula alnoides with six planting densities (625, 833, 1111, 1250, 1667, and 2500 stems per hectare (sph)) in Guangdong Province, South China. Branch quantity (number, proportion, and density), morphology (diameter, length, and angle), position (height and orientation), and branch status (dead or alive) were investigated for 54 dominant or co-dominant trees under six treatments of planting density after the growth of each tree was measured. Factors influencing branch development were also explored by mixed modelling. The results showed that the mean tree heights of 1250 and 1667 sph treatments were higher than those of other planting density treatments. The quantity of live branches decreased with increasing planting density. However, planting density had no significant effect on the number of all branches, and there existed no remarkable difference in branch number and proportion among four orientations. As for branch morphology, only the largest branch diameter had a significantly negative correlation with planting density. In addition, high planting density significantly increased the height of the largest branch within the crown. Mixed effects models indicated that branch diameter, length, and angle were closely correlated with each other, and they were all in positively significant correlation to the branch height at the stem section below six meters. It was concluded that properly increasing planting density will promote natural pruning, improve early branch control, and be beneficial for wood production from the most valuable section of the stem.

The domestic and foreign progress of picometer resolution measurements were reviewed.Typtical methods for measurement with high resolution(picometer resolution) were introduced,and the progress of picometer measurements was presented.The principles and corresponding subdivision techiniques were studied.Then,two novel measurements were proposed and analyzed.The multiple reflection interferometer was analyzed.It has the advantages of higher resoultion and more simplicity deivce than X-ray interferometer,which provide a good future in the fields of spectroscopy and high-precision measurement.

We have synthesized two Nb@C composites with an order of magnitude difference in the density of single-atom niobium substituted into graphitic layers. The concentration and sites of single-atom Nb are identified using aberration-corrected scanning transmission electron microscopy and density functional theory. Comparing the complex permittivity spectra show that the representative dielectric resonance at ~16 GHz originates from the intrinsic polarization of single-atom Nb sites, confirmed by theoretical simulations. The single-atom dielectric resonance represents the physical limit of the electromagnetic response of condensed matter, and thus might open up a new avenue for designing electromagnetic wave absorption materials. Single-atom resonance also has important implications in understanding the correlation between the macroscopic dielectric behaviors and the atomic-scale structural origin.

A multi-function ball screw measuring device is developed, which can achieve most of the parameter testing of ball screw like geometric accuracy, positional accuracy, reverse clearance, speed and acceleration, friction torque, preload, fatigue properties, temperature rise and so on. According to the supporting features of parameters testing, we can divide the test bed into two categories: double dead center test bed and double bearing seat test bed. The former is used to do low speed and high precision test experiments, and the latter is used to do high speed and heavy load test experiment. By the means of reasonable structure design and simply assembly, we can conduct these two kinds of test on the ball screw measuring device. In this way, not only the cost is cut down, but also the comprehensive and reliable evaluation for ball screw will be obtained. In this paper, detail introduction of test platform building and test program for different test parameters is given. The content of paper is divided into two parts, the first part describes the overall structure design, double dead center test platform building and geometric accuracy test program, the second part describes double bearing block test platform building and relevant test programs.

Chitosan, a polysaccharide isolated from shrimp and other crustacean shells, has been widely investigated for DNA and siRNA delivery. Despite substantial effort having been made to improve chitosan as a non-viral gene delivery vector, the application is severely limited by its poor solubility under physiological conditions. Hydroxybutyl chitosan (HBC), a modified chitosan, is soluble under neutral conditions. Tissue factor (TF) is involved in the pathogenesis of cardiovascular diseases by promoting thrombus formation and inducing the migration and proliferation of vascular smooth muscle cells. Targeting TF is an attractive therapeutic strategy for cardiovascular diseases. In the present study, the use of HBC for the transfer of TF-siRNAs into human umbilical vein smooth muscle cells (HUVSMCs) was investigated, and the effects of TF knockdown on cell proliferation and apoptosis were examined. HBC/siRNA nanoparticles were produced by mixing HBC and siRNA solutions with the assistance of tripolyphosphate buffer. The transfection efficiency with these nanoparticles was 74±2.5%, which was determined using a fluorescence-labeled siRNA under fluorescence microscopy. The delivery of HBC/TF-siRNA resulted in reductions in the production of cellular and soluble TF protein in HUVMSCs, which were measured using western blotting and enzyme-linked immunosorbent assay, respectively. TF knockdown led to inhibited cell proliferation, as assessed using a Cell Counting Kit-8 assay, and increased cell apoptosis, determined using Annexin V-fluorescein isothiocyanate staining. These findings suggested that HBC may be a promising vector for siRNA delivery, and that in vivo HBC/siRNA nanoparticle delivery targeting TF may be a potential option for the treatment of cardiovascular diseases, which warrants further investigation.

Premise of the study: Microsatellite markers were developed for Vatica mangachapoi (Dipterocarpaceae), an endangered species indigenous to Southeast Asia and southern China. Methods and Results: Twenty microsatellite markers, including 12 polymorphic markers, were identified from V. mangachapoi using high-throughput sequencing. Polymorphism at each marker was evaluated using 87 individuals from three natural populations. The number of alleles per polymorphic locus ranged from six to 15, and the observed and expected heterozygosity varied from 0.000 to 0.926 and from 0.177 to 0.864, respectively. These markers were transferred successfully to the endangered species V. guangxiensis. Conclusions: These markers may be used to investigate the genetic diversity and gene flow of V. mangachapoi and V. guangxiensis.

The laser tracker is an effective instrument for measuring 3D relative displacement in a work volume because its attitude can be freely changed. This paper presents a novel principle to realize the precise calibration of a numerical control (NC) machine tool accurately and quickly; this is the 'pose measurement principle', for measuring errors. We also introduce an algorithm for identifying geometric deviations. A NC precise table mounted on a motion axis and a laser tracker are used for the coordinate determination of three fixed points to obtain the pose information of each motion axis, then calculate the pose deviations, and finally identify all the errors. For the error identification, first, according to the definition of geometric errors, we extend the concept of pose deviations, and represent the six geometric errors using a position deviation vector and attitude deviation vector. Next, we geometrically identify the three angular errors and linear errors in order; the error mathematical model for the linear axis and rotary axis are developed, respectively. Moreover, the validity of the calibration algorithm for the base station, measuring points and identification of errors are confirmed by simulations. In the end, the proposed method is applied to a three-axis NC milling machine tool and a rotary table, and then the geometric deviations are identified successfully in 3 h and 2.5 h, respectively. Comparative experiments by means of other instruments also agree well with the proposed method. Thus, the proposed method can be applied to the measurement of the multi-axis machine tool.

This paper focuses on the domain knowledge management of expressway networks in Intelligent Transport Systems and develops ontology for them by reusing SUMO (Suggested Upper Merge Ontology) as the upper ontology. The approached ontology names SENO (SUMO-based Expressway Network Ontology) and consists of two parts, among which SENO Basic is the set of shared concepts and relations, whereas SENO Core divides key concepts and relations into several categories according to the pattern of semantic organization of information in expressway network. As illustrated in a case study, SENO can be instantiated to form a comprehensive semantic view of the domain knowledge to eliminate ambiguities among heterogeneous systems, and to better promote knowledge management and information sharing for expressway network.

Fisher?s discriminant requires the inverse operation of high-order within-class scatter matrix [Sw] in the dimensionality reduction of feature vectors. The results may be inaccurate if [Sw] is close to singular. This paper presents another classification-oriented mapping method for the dimensionality reduction of high-dimensional feature vectors, based on the generalized cross product of multi-vectors. The mapped feature vector is transformed into a cross matrix to generate a product vector, whose robustness depends on both the orthogonality and the norm-homogeneousness of the cross matrix, for pattern classification. To insure the within-class congregation and between-class separability of the mapping of feature vectors, it is proved that the optimum cross matrix is merely the orthonormalized basis of 2 reference vectors of sorted sample sets according to the robustness theorem of generalized cross product proposed in this paper. Numerical experiments showed that the proposed method has a better separability and better robustness of separability than Fisher?s method in the dimensionality reduction of high-dimension feature vectors.

Based on the features of circle-like edge in digital image, an algorithm is presented in which the evolute of edge is calculated and from its distribution, the circles are located. The edge of target is first extracted and traced. Then the centers of curvature are calculated by least square fitting in fraction of edge and thus the evolute of edge is worked out. From the evolute distribution and the fitting degree, the circles can be recognized and their radii and centers are calculated. Experiments show that by the proposed method, circle-like target in image can be detected efficiently and accurately. And it is effective even for the distorted and deformed circles.

Onion-like fullerenes (OLFs) were generated by arc discharge in water between pure graphite electrodes. The size and crystalline morphology of the generated OLFs were characterized by means of the high-resolution transmission electron microscopy and X-ray diffraction. Furthermore, OLFs were added to base lubricant and the tribological property of OLFs was investigated by using a four-ball type tribometer. The results indicated that the OLFs with diameter about 25 nm were of high degree graphitization. Good friction-reduction property at different additive concentration and applied load as lubricant additive was obtained. The scratches on the worn surfaces become slighter and more uniform with addition of OLFs to the base lubricant. In addition, the tribological mechanism of the sliding-bearing system was proposed.

Background: The recent reports of two circular RNAs (circRNAs) with strong potential to act as microRNA (miRNA) sponges suggest that circRNAs might play important roles in regulating gene expression. However, the global properties of circRNAs are not well understood. Results: We developed a computational pipeline to identify circRNAs and quantify their relative abundance from RNA-seq data. Applying this pipeline to a large set of non-poly(A)-selected RNA-seq data from the ENCODE project, we annotated 7,112 human circRNAs that were estimated to comprise at least 10% of the transcripts accumulating from their loci. Most circRNAs are expressed in only a few cell types and at low abundance, but they are no more cell-type-specific than are mRNAs with similar overall expression levels. Although most circRNAs overlap protein-coding sequences, ribosome profiling provides no evidence for their translation. We also annotated 635 mouse circRNAs, and although 20% of them are orthologous to human circRNAs, the sequence conservation of these circRNA orthologs is no higher than that of their neighboring linear exons. The previously proposed miR-7 sponge, CDR1as, is one of only two circRNAs with more miRNA sites than expected by chance, with the next best miRNA-sponge candidate deriving from a gene encoding a primate-specific zinc-finger protein, ZNF91. Conclusions: Our results provide a new framework for future investigation of this intriguing topological isoform while raising doubts regarding a biological function of most circRNAs., National Institutes of Health (U.S.) (Grant GM067031), National Science Foundation (U.S.). Graduate Research Fellowship, Damon Runyon Cancer Research Foundation (DRG-2152-13)