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The increasing occurrence of bacterial infection at the wound sites is a serious global problem, demanding the rapid development of new antibacterial materials for wound dressing to avoid the abuse of antibiotics and thereby antibiotic resistance. In this work, the authors first report on antibacterial N-halamine polymer nanomaterials based on a strategic copolymerization of 3-allyl-5,5-dimethylhydantoin (ADMH) and methyl methacrylate (MMA), which exhibits in vitro and in vivo antimicrobial efficacy against pathogenic bacteria including Staphylococcus aureus and Escherichia coli. Particularly, when a biological evaluation is run for wound therapy, the N-halamine polymer nanomaterials exhibit a powerful antibacterial efficiency and wound healing ability after a series of histological examination of mouse wound. After the evaluation of biological and chemical surroundings, the proposed four-stage mechanism suggests that, with unique antibacterial NCl bonds, the N-halamine polymer nanomaterials can disrupt the bacterial membrane, as a result causing intracellular content leaked out and thereby cell death. Based on the synergistic action of antibacterial and wound therapy, the N-halamine polymer nanomaterials are expected to be promising as wound dressing materials in medical healing and biomaterials.

Phosphorus is the second most important macronutrient after nitrogen and it has many vital functions in the life of plants. Most soils have a low available P content, which has become a key limiting factor for increasing crop production. Also, low P use efficiency (PUE) of crops in conjunction with excessive application of P fertilizers has resulted in serious environmental problems. Thus, dissecting the genetic architecture of crop PUE, mining related quantitative trait loci (QTL) and using molecular breeding methods to improve high PUE germplasm are of great significance and serve as an efficient approach for the development of sustainable agriculture. In this review, molecular and phenotypic characteristics of maize inbred lines with high PUE, related QTL and genes as well as low-P responses are summarized. Based on this, a breeding strategy applying genomic selection as the core, and integrating the existing genetic information and molecular breeding techniques is proposed for breeding high PUE maize inbred lines and hybrids.

A novel type of slow-wave structure, two-beam folded waveguide (FW) operating at terahertz (THz) band, is presented in this paper. The propagating characteristics of two-beam FW are investigated. Results of different methods including field matching and equivalent circuit are compared for the calculating dispersion of two-beam FW for THz radiation. The equivalent circuit model considers the circular bends and beam tunnels without electron beams. Field matching analysis considers both of the electron beams and the circular bends. Moreover, results from CST microwave studio simulations are compared with above different methods to find a sufficiently accurate prediction of dispersion of two-beam FW.

MicroRNAs (miRNAs) are a family of small non-coding RNA molecules that regulate gene expression at post-transcriptional levels. Previous studies have shown that miR-145 is downregulated in human ovarian cancer; however, the roles of miR-145 in ovarian cancer growth and invasion have not been fully demonstrated. In the present study, Northern blot and qRT-PCR analysis indicate that miR-145 is downregulated in ovarian cancer tissues and cell lines, as well as in serum samples of ovarian cancer, compared to healthy ovarian tissues, cell lines and serum samples. Functional studies suggest that miR-145 overexpression leads to the inhibition of colony formation, cell proliferation, cell growth viability and invasion, and the induction of cell apoptosis. In accordance with the effect of miR-145 on cell growth, miR-145 suppresses tumor growth in vivo. MiR-145 is found to negatively regulate P70S6K1 and MUC1 protein levels by directly targeting their 3'UTRs. Importantly, the overexpression of p70S6K1 and MUC1 can restore the cell colony formation and invasion abilities that are reduced by miR-145, respectively. MiR-145 expression is increased after 5-aza-CdR treatment, and 5-aza-CdR treatment results in the same phenotype as the effect of miR-145 overexpression. Our study suggests that miR-145 modulates ovarian cancer growth and invasion by suppressing p70S6K1 and MUC1, functioning as a tumor suppressor. Moreover, our data imply that miR-145 has potential as a miRNA-based therapeutic target for ovarian cancer.

Placenta and umbilical cord blood are important media for investigating maternal-fetal exposure to environmental pollutants. Historically hexachlorocyclohexanes (HCHs) were once widely-used in China. In this study, residues of HCHs were measured in placenta and umbilical cord blood samples for 40 women from Beijing. The measured median values of HCHs were 62.0 and 68.8 ng/g fat in placenta and umbilical cord blood, respectively. Concentrations of HCHs in placenta and umbilical cord blood of urban cohort were higher than those of rural group due to enhanced consumption of fish, meat, and milk. Residues of HCHs in placenta were significantly correlated with total food consumption, dietary intake, and maternal age, and could be predicted using the parameters dependent upon ingestion of meat and milk. The transplacental exposure of fetuses to HCHs was revealed by a close association between the residual levels in the paired placenta and the paired umbilical cord blood samples.

Stalk bending strength (SBS) is a reliable indicator for evaluating stalk lodging resistance of maize plants. Based on biomechanical considerations, the maximum load exerted to breaking (F max), the breaking moment (M max) and critical stress (σ max) are three important parameters to characterize SBS. We investigated the genetic architecture of SBS by phenotyping F max, M max and σ max of the fourth internode of maize plants in a population of 216 recombinant inbred lines derived from the cross B73 × Ce03005 evaluated in four environments. Heritability of F max, M max and σ max was 0.81, 0.79 and 0.75, respectively. F max and σ max were positively correlated with several other stalk characters. By using a linkage map with 129 SSR markers, we detected two, three and two quantitative trait loci (QTL) explaining 22.4, 26.1 and 17.2 % of the genotypic variance for F max, M max and σ max, respectively. The QTL for F max, M max and σ max located in adjacent bins 5.02 and 5.03 as well as in bin 10.04 for F max were detected with high frequencies in cross-validation. As our QTL mapping results suggested a complex polygenic inheritance for SBS-related traits, we also evaluated the prediction accuracy of two genomic prediction methods (GBLUP and BayesB). In general, we found that both explained considerably higher proportions of the genetic variance than the values obtained in QTL mapping with cross-validation. Nevertheless, the identified QTL regions could be used as a starting point for fine mapping and gene cloning.

When wind power penetration is high, the available generation may be more than needed, especially for wind-powered microgrids working autonomously. Because the maximum peak power tracking algorithm may result in a supply-demand imbalance, an alternative algorithm is needed for load sharing. In this paper, a fully distributed control scheme is presented to coordinate the operations of multiple doubly-fed induction generators (DFIGs) in a microgrid. According to the proposed control strategy, each bus in a microgrid has an associated bus agent that may have two function modules. The global information discovery module discovers the total available wind generation and total demand. The load sharing control module calculates the generation reference of a DFIG. The consensus-based algorithm can guarantee convergence for microgrids of arbitrary topologies under various operating conditions. By controlling the utilization levels of DFIGs to a common value, the supply-demand balance can be maintained. In addition, the detrimental impact of inaccurate and outdated predictions of maximum wind power can be alleviated. The generated control references are tracked by coordinating converter controls and pitch angle control. Simulation results with a 5-DFIG microgrid demonstrate the effectiveness of the proposed control scheme.

The temporal trends in daily dietary exposure of the populations in Beijing and Shenyang, China to DDTs and HCHs through consumption of various food categories and the associated health risks were investigated in this work. The estimated dietary intakes of DDTs and HCHs in 2005/2007 were almost one and two orders of magnitude lower than those in 1992 and in the 1970s, respectively, revealing the historical decrease of DDT and HCH in Chinese foods after their applications were banned. The relative contributions of different foodstuffs to the overall intakes of DDTs and HCHs in the 1970s and in 1992 were very different from those in 2005/2007, mainly due to the remarkable concentration variance in foodstuffs and changes in diet habit of population. According to the hazard guidelines, it is concluded that intakes of these two pesticides in 2005/2007 may not exert adverse effects on human health.

Residential energy consumptions of both electricity and fuels are associated with emissions of many air pollutants. Temporally and spatially resolved energy consumption data are scarce in China, which are critical for a better understanding of their environmental impacts. In this study, a space-for-time substitution method was proposed and two models for predicting fuel and electricity consumptions in residential sector of China were developed using provincial data. It was found that fuel consumption was not directly proportional to heating degree day and was also affected by heating day, defined as the number of days when heating is required in a year. The models were validated against a set of historical annual data and two sets of survey data on seasonal variations. The models were applied to predict spatial and temporal variations of residential energy consumptions and emissions of various pollutants and to predict net effects of climate warming on energy consumptions and pollutant emissions. The emissions of black carbon (BC), carbon monoxide (CO), and polycyclic aromatic carbons (PAHs) in winter were significantly higher than those in other seasons. For the emissions of carbon dioxide (CO 2 ), sulfur dioxide (SO 2 ), and nitrogen oxides (NO x ), there were two peaks in winter and summer, with the latter increasing gradually over years. It was predicted that per-capita residential energy consumptions would reach 0.43, 0.33, and 0.26 toe/cap in 2050 for IPCC scenarios of A1B, B1, and A2, respectively. Climate warming in the future would lead to less residential fuel but more electricity consumptions. Consequently, emissions of BC, CO, and PAHs would decrease mainly in cold climate zones, while emissions of CO 2 , SO 2 , and NO x would increase largely in southeast China.

Global atmospheric emissions of 16 polycyclic aromatic hydrocarbons (PAHs) from 69 major sources were estimated for a period from 1960 to 2030. Regression models and a technology split method were used to estimate country and time specific emission factors, resulting in a new estimate of PAH emission factor variation among different countries and over time. PAH emissions in 2007 were spatially resolved to 0.1° × 0.1° grids based on a newly developed global high-resolution fuel combustion inventory (PKU-FUEL-2007). The global total annual atmospheric emission of 16 PAHs in 2007 was 504 Gg (331-818 Gg, as interquartile range), with residential/commercial biomass burning (60.5%), open-field biomass burning (agricultural waste burning, deforestation, and wildfire, 13.6%), and petroleum consumption by on-road motor vehicles (12.8%) as the major sources. South (87 Gg), East (111 Gg), and Southeast Asia (52 Gg) were the regions with the highest PAH emission densities, contributing half of the global total PAH emissions. Among the global total PAH emissions, 6.19% of the emissions were in the form of high molecular weight carcinogenic compounds and the percentage of the carcinogenic PAHs was higher in developing countries (6.22%) than in developed countries (5.73%), due to the differences in energy structures and the disparities of technology. The potential health impact of the PAH emissions was greatest in the parts of the world with high anthropogenic PAH emissions, because of the overlap of the high emissions and high population densities. Global total PAH emissions peaked at 592 Gg in 1995 and declined gradually to 499 Gg in 2008. Total PAH emissions from developed countries peaked at 122 Gg in the early 1970s and decreased to 38 Gg in 2008. Simulation of PAH emissions from 2009 to 2030 revealed that PAH emissions in developed and developing countries would decrease by 46-71% and 48-64%, respectively, based on the six IPCC SRES scenarios.

Health effects attributable to air pollution exposure in Chinese population have been least understood. The authors conducted a meta-analysis on 33 time-series and case-crossover studies conducted in China to assess mortality effects of short-term exposure to particulate matter with aerodynamic diameters less than 10 and 2.5 μm (PM10 and PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3) and carbon monoxide (CO). Significant associations between air pollution exposure and increased mortality risks were observed in the pooled estimates for all pollutants of interest. In specific, each 10 μg/m3 increase in PM2.5 was associated with a 0.38% (95% Confidence Interval, CI: 0.31, 0.45) increase in total mortality, a 0.51% (95% CI: 0.30, 0.73) in respiratory mortality, and a 0.44% (95% CI: 0.33, 0.54) in cardiovascular mortality. When current annual PM2.5 levels in mega-Chinese cities to be reduced to the WHO Air Quality Guideline (AQG) of 10 μg/m3, mortality attributable to short-term exposure to PM2.5 could be reduced by 2.7%, 1.7%, 2.3%, and 6.2% in Beijing, Shanghai, Guangzhou and Xi'an, respectively. The authors recommend future studies on the nature of air pollution concentration and health effect relationships in Chinese population to support setting stringent air quality standards to improve public health. Keywords: Meta-analysis, Air pollution, Mortality, Exposure–response relationship, Health impact assessment, China

High levels of polybrominated diphenyl ethers (PBDEs) have been extensively reported in urban areas and at e-waste recycling sites in coastal China. However, data are scarce in northern China and are not available in rural areas at all. In addition, it is often believed that air concentrations in rural areas are lower than those in urban areas without distinguishing rural residential areas and open fields. In this study, air samples were collected at 17 sites covering urban and rural (residential and open field) areas in northern China using active samplers. With BDE-209 dominated in all congeners, the average concentrations of BDE-209 (41 +/- 72 pg/m(3)) and other 13 PBDEs (16 +/- 12 pg/m(3)) were significantly lower than those found in south China, such as in Guangzhou or Hong Kong. On average, the total PBDE concentrations at the urban sites were 2.2 and 2.9 times of those at the rural residential and field sites, respectively. (C) 2012 Elsevier Ltd. All rights reserved.

243 surface soil samples were collected from the Yangtze River Delta (YRD) region, and the concentration distributions and compositional profiles of 27 parent PAHs (PPAHs), nitro- and oxy-derivatives (NPAHs and OPAHs), respectively, and health risk of 16 PPAHs were determined. Atmospheric samples were collected at two sites with high topsoil concentrations of PAHs to assist in identifying the emission sources of PPAHs. The total concentrations of PPAHs, NPAHs and OPAHs fell in the ranges of 21.0-3563.2 ng/g, 0.4-4.6 ng/g and 2.1-834.1 ng/g, respectively. PPAHs in topsoil were dominated by low and medium molecular weight species. The main components of OPAHs were 9FO and ANQ. For NPAHs, only 1N-NAP was frequently detected. Overall, the northern parts of the YRD region were more heavily contaminated by PPAHs and their corresponding derivatives. The soil TOC fraction and GDP per capita were significantly correlated with the spatial distribution of PPAHs. Specific ratios of isomeric species and principal component analysis (PCA) designated combustion of industrial coal and biomass, and traffic exhaust as the main mixed emission sources of PPAHs in surface soils in this region. The detected NPAHs and OPAHs were significantly associated with the corresponding PPAHs. The estimated incremental lifetime cancer risk attributed to 16 PPAHs in surface soil was greater than 10-6, indicating a potential risk of contracting cancer by exposure to topsoil from the YRD region. The cumulative probability of cancer risk for both adults and children via three exposure pathways followed the sequence of dermal contact > ingestion > inhalation.

In this paper, an adaptive decentralized fuzzy control scheme is presented for a class of multiple-input and multiple-output (MIMO) nonlinear interconnected systems with unmodeled dynamics and dead zones. In the controller design procedure, fuzzy logic systems are used to approximate the unknown nonlinear functions and then an adaptive fuzzy controller is developed by combining adaptive technique with backstepping. The proposed control scheme can guarantee that all signals in the closed-loop system are semi-globally uniformly ultimately bounded in mean square. Simulation results are provided to illustrate the effectiveness of the proposed scheme.

Cadmium (Cd) pollution has aroused increasing attention due to its toxicity. It has been proved that Na

A simple terahertz oscillator with corrugated cylindrical waveguide is presented in this paper. Using the simple unified theory, the beam-wave interactions are analyzed in the corrugated periodic metal slow-wave structure (SWS).

In this paper, a three-section periodical grating structure (PGS) is investigated for Smith-Purcell (SP) backward wave oscillator (BWO). The first and second sections are used to pre-modulate the electron beam and the open grating (section-III) is for terahertz SP radiation. By theoretical analysis and particle-in-cell simulations, the SP radiation is studied in detail. The results show that the three-section PGS can drastically reduce the starting current of SP BWO, thereby generate the high frequency terahertz waves.

Extended Interaction Oscillator (EIO) play an important role in many classes of vacuum electronic device. The device which compare with the others has many advantages. Simulation and texting of electron optics system for 0.1THz EIO are described in this article. For getting a small structure, the structure of permanent magnet focusing system had been designed. Some optimized parameters of electron optics system (EOS) had been obtained by two codes, Egun and Superfish. According to the results of simulation, 0.1THz EIO had been made and the experiment of the device had been accomplished subsequently. The results show that electron beam has highly passing rate and low ripple. The 0.1THz EIO which use the optimized EOS output 107.6GHz signal and the peak power of the device is 10.3W.

In this paper, a two-section folded waveguide (TSFW) structure for generating prebunching beam in terahertz (THz) extended interaction oscillator (EIO) is presented and demonstrated. For the realized aim of prebunching beam in the TSFW, it is split into two halves. With help of high speed numerical mill, the TSFW is manufactured. To avoid the effects of size deformation on the interaction of beam-wave and blocking beam channel, the TSFW is integrated by diffusing welding. After the key components being finished, the TSFW of EIO is vacuum-sealed. At IECAS, two kinds of EIO are developed, which are the 0.1THz and 0.3THz, and experimental results show that the output power exceeds 10W and 4.0W, respectively.

In this paper, a design scheme for a traveling-wave tube amplifier (TWTA) above 0.3 THz using folded waveguide (FW) slow-wave structure (SWS) is introduced. Based on the calculation on the dispersion characteristics and coupling impedance of FW, the initial value of geometrical parameters for FW is given. Three dimensional PIC simulation method is adopted to study the output power, gain and bandwidth of the TWTA. Design of high gain and broadband TWTA is realized on the basis of geometrical and electromagnetic parameter optimization with PIC method. In order to suppress oscillation of output power, two-section folded waveguide with attenuating material is also simulated and it shows good results. This work lays the foundation for developing vacuum electronic THz sources.

Uninterruptible Power Supply (UPS) is widely utilized to provide stable and high quality electricity for varying loads. Moreover, it is a critical means to maintain the voltage level of a microgrid with low-inertia. The control performance of UPS system directly affects the reliability and electricity quality of a microgrid. A large voltage deviation could result in component failure or even grid shutdown. In this paper, an adaptive performance-guaranteed controller is proposed for UPS integrated microgrid suffering from unknown parameters and nonlinear loads. A constrained state-space model of the plant is firstly developed and transformed into an equivalent unconstrained one via an error transformation technique. An adaptive controller is subsequently designed for the transformed system by using backstepping scheme. By this means, the bus voltage can be guaranteed to stay within arbitrarily user-defined bounds. Furthermore, all signals within the closed-loop system are proved to be bounded thru Lyapunov synthesis. Finally, the feasibility of the theoretical results is demonstrated via extensive simulation and experimental studies.

The current contamination status of polychlorinated biphenyls (PCBs) was studied in the agricultural soils of the Yangtze River Delta (YRD), one of the largest economic zones in China. The concentrations of PCBs ranged from0.1 to 130 ng/g dry weight. Higher concentrations of PCBs were observed in the 0-30 cm surface layers relative to the subsurface soils. A distinct spatial distribution was observed with a declining concentration gradient from the northwest to the southeast of the region. The composition of PCBs in the soils was consistent with the Chinese commercial PCB mixtures, but different from the compositions in global background soil. Local sources including large-scale use and disposal of PCB-containing products were the main potential sources to soil. The ecological effects and human health risks associated with combined persistent organic pollutants, including PCBs, organochlorine pesticides (OCPs), phthalate esters (PAEs) and polybrominated diphenyl ethers (PBDEs), were further estimated. The four toxic organic compounds and seven physicochemical parameters together could only explain 12.7% of the variation in microbial community composition, suggesting the soil ecosystem function was not strongly influenced by the combined pollution at low concentrations. However, the potential health risks to residents via multiple pathways were notably higher for PCBs than other chemicals. The potential risks were mainly derived from PCB-126, 81, and 169.

A sapphire output window is designed for 108GHz folded waveguide traveling-wave tube (FW-TWT). The voltage standing wave ratio (VSWR) is calculated using CST Microwave Studio (MWS). The transmission modes in the window are analyzed. Thermal analysis of the output window using ANSYS package is presented. With different power losses in the window, temperature, total deformation and equivalent stress had been simulated considering different transmission modes in the window. The results show that all aspects of the designed output window can meet the requirement of thermodynamics.

This paper describes a particular design of a Pierce gun and a compact PPM focusing system for 108GHz serpentine TWT applications. Design strategies are proposed by providing closed formulas and dimensioning techniques. The influence of focusing electrode dimension has been presented in gun structure design. The optimum value of magnetic induction has been discussed in PPM structure design. Using this design, a well focused electron beam can be obtained.

The paper presents a novel cascaded folded waveguide traveling wave tube (FW-TWT) interacting with two beams operating at TE 20 mode. This cascaded structure is constructed by two sections. The downstairs section interacts with the two beams to amplify the signal initially. It also provides the upstairs section with small input power. The upstairs section continues to amplifying the signal. Both the two sections adopt two beams and operating at TE 20 mode.

In this paper, a simulation on the evanescent wave of Smith-Purcell (SP) radiation from dielectric loaded grating (DLG) is presented at terahertz frequencies. The evanescent wave provides feedback to bunch the electron beam, which is the basis of oscillator operation of SP free-electron laser (FEL). The results obtained from particle-in-cell (PIC) code are compared with metal grating, which show that the usage of DLG can enhance the evanescent wave, which can further improve the beam-wave interaction.

Enhance the efficiency of beam-wave interaction is an important problem in the design of folded waveguide traveling-wave tube (TWT) amplifier. A dielectric-loaded tapered folded waveguides was studied, whose equivalent circuit analysis is mainly introduced in this paper.

This paper presents a simulation of Smith-Purcell (SP) radiation from dielectric loaded grating (DLG) at terahertz frequencies, which is performed by using a two-dimensional (2D) particle-in-cell (PIC) code. The simulation supposes a continuous electron beam passing over a DLG and metal grating, respectively. The results show that compared with metal grating, the usage of DLG can enhance the radiation intensity.

Background Doubled haploid (DH) lines produced via in vivo haploid induction have become indispensable in maize research and practical breeding, so it is important to understand traits characteristics in DH and its corresponding haploids which derived from each DH lines. In this study, a DH population derived from Zheng58 × Chang7-2 and a haploid population, were developed, genotyped and evaluated to investigate genetic architecture of eight stalk traits, especially rind penetrometer resistance (RPR) and in vitro dry matter digestion (IVDMD), which affecting maize stalk lodging-resistance and feeding values, respectively. Results Phenotypic correlation coefficients ranged from 0.38 to 0.69 between the two populations for eight stalk traits. Heritability values of all stalk traits ranged from 0.49 to 0.81 in the DH population, and 0.58 to 0.89 in the haploid population. Quantitative trait loci (QTL) mapping study showed that a total of 47 QTL for all traits accounting for genetic variations ranging from 1.6 to 36.5 % were detected in two populations. One or more QTL sharing common region for each trait were detected between two different ploidy populations. Potential candidate genes predicated from the four QTL support intervals for RPR and IVDMD were indirectly or directly involved with cellulose and lignin biosynthesis, which participated in cell wall formation. The increased expression levels of lignin and cellulose synthesis key genes in the haploid situation illustrated that dosage compensation may account for genome dosage effect in our study. Conclusions The current investigation extended understanding about the genetic basis of stalk traits and correlations between DH and its haploid populations, which showed consistence and difference between them in phenotype, QTL characters, and gene expression. The higher heritabilities and partly higher QTL detection power were presented in haploid population than in DH population. All of which described above could lay a preliminary foundation for genetic architecture study with haploid population and may benefit selection in haploid-stage to reduce cost in DH breeding. Electronic supplementary material The online version of this article (doi:10.1186/s12870-016-0742-3) contains supplementary material, which is available to authorized users.

In this work, a new method for calculating the solid-liquid interfacial energy was proposed by the combining of the classical nucleus method (CNM) and capillary fluctuation method (CFM). The anisotropy of interfacial energies of Al increases as the temperature drops, while the orientationally averaged interfacial energy shows no such kind of tendency.

Route used to develop DH population and the corresponding haploid populations. Figure S2. Presentation of DH and haploid populations planted in field. Figure S3. Histogram for genotypic percentage in DH population. Figure S4. QTL detected frequency for RPR and IVDMD in DH and haploid populations with five-split cross validation for 1000 times. For RPR, the QTL at bin 2.02 and 5.05 were detected in DH and haploid population with high frequencies in the 1000 cross-validation, respectively. For IVDMD, the QTL at bin 8.04 and 8.05 were detected in DH and haploid population with high frequencies in the 1000 cross-validation, respectively. Table S1. Primer sequences of genes involved in lignin and cellulose synthesis for RT-PCR. Table S2. Summary of SNP characteristics of DH population. Table S3. Summary of the linkage map characteristics DH population. Table S4. QTL detected for other stalk traits in DH and haploid populations. Table S5. Annotation of the 45 predicted genes located within putative RPR QTL interval in DH population. Table S6. Annotation of the 191 predicted genes located within putative RPR QTL interval in haploid population. Table S7. Annotation of the 24 predicted genes located within the putative IVDMD QTL interval in DH population. Table S8. Annotation of the 191 predicted genes located within putative IVDMD QTL interval in haploid population. (DOCX 870 kb)

Genomic selection (GS) is a promising alternative to marker-assisted selection particularly for quantitative traits. In this study, we examined the prediction accuracy of genomic breeding values by using ridge regression best linear unbiased prediction in combination with fivefold cross-validation based on empirical data of a commercial maize breeding programme. The empirical data is composed of 930 testcross progenies derived from 11 segregating families evaluated at six environments for grain yield and grain moisture. Accuracy to predict genomic breeding values was affected by the choice of the shrinkage parameter λ2, by unbalanced family size, by size of the training population and to a lower extent by the number of markers. Accuracy of genomic breeding values was high suggesting that the selection gain can be improved implementing GS in elite maize breeding programmes.

This paper proposes a fully distributed multiagent-based reinforcement learning method for optimal reactive power dispatch. According to the method, two agents communicate with each other only if their corresponding buses are electrically coupled. The global rewards that are required for learning are obtained with a consensus-based global information discovery algorithm, which has been demonstrated to be efficient and reliable. Based on the discovered global rewards, a distributed Q-learning algorithm is implemented to minimize the active power loss while satisfying operational constraints. The proposed method does not require accurate system model and can learn from scratch. Simulation studies with power systems of different sizes show that the method is very computationally efficient and able to provide near-optimal solutions. It can be observed that prior knowledge can significantly speed up the learning process and decrease the occurrences of undesirable disturbances. The proposed method has good potential for online implementation.

Family mapping is based on multiple segregating families and is becoming increasingly popular because of its advantages over population mapping. Athough much progress has been made recently, the optimum design and allocation of resources for family mapping remains unclear. Here, we addressed these issues using a simulation study, resample model averaging and cross-validation approaches. Our results show that in family mapping, the predictive power and the accuracy of quatitative trait loci (QTL) detection depend greatly on the population size and phenotyping intensity. With small population sizes or few test environments, QTL results become unreliable and are hampered by a large bias in the estimation of the proportion of genotypic variance explained by the detected QTL. In addition, we observed that even though good results can be achieved with low marker densities, no plateau is reached with our full marker complement. This suggests that higher quality results could be achieved with greater marker densities or sequence data, which will be available in the near future for many species.

Linkage mapping based on multiple-line crosses is a promising strategy for mapping quantitative trait loci (QTL) underlying important agronomic traits. The main goal of this survey was to study the advantages of QTL mapping across versus within biparental populations using experimental data from three connected sugar beet (Beta vulgaris L.) populations evaluated for beet yield and potassium and sodium content. For the combined analysis across populations, we used two approaches for cofactor selection. In Model A, we assumed identical cofactors for every segregating population. In contrast, in Model B we selected cofactors specific for every segregating population. Model A performed better than Model B with respect to the number of QTL detected and the total proportion of phenotypic variance explained. The QTL analyses across populations revealed a substantially higher number of QTL compared to the analyses of single biparental populations. This clearly emphasizes the potential to increase QTL detection power with a joint analysis across biparental populations.

Because of its high efficiency, robustness, and high power density, a permanent magnet synchronous machine (PMSM) is a desirable choice for high-performance applications, such as naval shipboard power systems. The stator winding fault is the most common electrical fault in PMSM; thus, detection of this type of fault is very important. The objective of this paper is to model and detect the location and severity of the stator winding fault of PMSM. To achieve this objective, a mathematical model that can describe both healthy and fault conditions is developed. Simulation results match the observations of this type of fault in the literature. According to the fault model, two parameters associated with fault location and fault severity must be identified in order to detect the fault. Because of the complex distribution of these two parameters in the fault model, the identification problem is extremely difficult for nonlinear identification techniques. To overcome this difficulty, the detection/identification problem is first transformed into a corresponding optimization problem and then solved using particle swarm optimization (PSO). By simulating a modified model instead of the original model, the PSO-based identification algorithm is able to identify the fault in real time. The real-time PSO-based identification algorithm also can be applied to many other identification problems.

The spatial variation in concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in surface soils in the North China Plain and the influential factors were examined in the present study. High concentrations of the sum of 16 PAHs (∑PAH(16) ) appeared in cities and their surrounding areas. Emissions and soil organic carbon (SOC) content significantly regulated spatial differentiation of PAH contamination in soils in the study area. Compared with emissions, concentrations of individual and total PAHs in soils were more closely controlled by the SOC content. Furthermore, concentrations of PAH species with lower molecular weight (e.g., two- or three-ring) in surface soils were more strongly correlated with the SOC content in comparison with those of higher molecular weight (e.g., five- or six-ring), mainly because of their higher saturated vapor pressure, thus higher mobility. The spatial variation of PAH species in soils in the North China Plain tended to be larger with increasing benzene ring numbers, and the difference in physicochemical properties of PAH species determined their distinct spatial distribution characteristics. The present study highlights the relative importance of emissions and SOC content in spatial variation of PAHs and the dependence of the spatial distribution characteristics of PAH species in surface soils on their physicochemical properties at a regional scale. Results of the present work are helpful for regional risk assessment of the contaminants tested.

Residential wood combustion is one of the important sources of air pollution in developing countries. Among the pollutants emitted, parent polycyclic aromatic hydrocarbons (pPAHs) and their derivatives, including nitrated and oxygenated PAHs (nPAHs and oPAHs), are of concern because of their mutagenic and carcinogenic effects. In order to evaluate their impacts on regional air quality and human health, emission inventories, based on realistic emission factors (EFs), are needed. In this study, the EFs of 28 pPAHs (EF(PAH28)), 9 nPAHs (EF(PAHn9)), and 4 oPAHs (EF(PAHo4)) were measured for residential combustion of 27 wood fuels in rural China. The measured EF(PAH28), EF(PAHn9), and EF(PAHo4) for brushwood were 86.7 ± 67.6, 3.22 ± 1.95 × 10(-2), and 5.56 ± 4.32 mg/kg, which were significantly higher than 12.7 ± 7.0, 8.27 ± 5.51 × 10(-3), and 1.19 ± 1.87 mg/kg for fuel wood combustion (p0.05). Sixteen U.S. EPA priority pPAHs contributed approximately 95% of the total of the 28 pPAHs measured. EFs of pPAHs, nPAHs, and oPAHs were positively correlated with one another. Measured EFs varied obviously depending on fuel properties and combustion conditions. The EFs of pPAHs, nPAHs, and oPAHs were significantly correlated with modified combustion efficiency and fuel moisture. Nitro-naphthalene and 9-fluorenone were the most abundant nPAHs and oPAHs identified. Both nPAHs and oPAHs showed relatively high tendencies to be present in the particulate phase than pPAHs due to their lower vapor pressures. The gas-particle partitioning of freshly emitted pPAHs, nPAHs, and oPAHs was primarily controlled by organic carbon absorption.

Flowering time is a fundamental quantitative trait in maize that has played a key role in the postdomestication process and the adaptation to a wide range of climatic conditions. Flowering time has been intensively studied and recent QTL mapping results based on diverse founders suggest that the genetic architecture underlying this trait is mainly based on numerous small-effect QTL. Here, we used a population of 684 progenies from five connected families to investigate the genetic architecture of flowering time in elite maize. We used a joint analysis and identified nine main effect QTL explaining approximately 50 % of the genotypic variation of the trait. The QTL effects were small compared with the observed phenotypic variation and showed strong differences between families. We detected no epistasis with the genetic background but four digenic epistatic interactions in a full 2-dimensional genome scan. Our results suggest that flowering time in elite maize is mainly controlled by main effect QTL with rather small effects but that epistasis may also contribute to the genetic architecture of the trait.

Root system architecture (RSA) is seldom considered as a selection criterion to improve yield in maize breeding, mainly because of the practical difficulties with their evaluation under field conditions. In the present study, phenotypic profiling of 187 advanced-backcross BC(4)F(3) maize lines (Ye478 × Wu312) was conducted at different developmental stages under field conditions at two locations (Dongbeiwang in 2007 and Shangzhuang in 2008) for five quantitative root traits. The aims were to (1) understand the genetic basis of root growth in the field; (2) investigate the contribution of root traits to grain yield (GY); and (3) detect QTLs controlling root traits at the seedling (I), silking (II) and maturation (III) stages. Axial root (AR)-related traits showed higher heritability than lateral root (LR)-related traits, which indicated stronger environmental effects on LR growth. Among the three developmental stages, root establishment at stage I showed the closest relationship with GY (r = 0.33-0.43, P 0.001). Thirty QTLs for RSA were detected in the BC(4)F(3) population and only 13.3 % of the QTLs were detected at stage III. Most important QTLs for root traits were located on chromosome 6 near the locus umc1257 (bin 6.02-6.04) at stage I, and chromosome 10 near the locus umc2003 (bin 10.04) for number of AR across all three developmental stages. The regions of chromosome 7 near the locus bnlg339 (bin 7.03) and chromosome 1 near the locus bnlg1556 (bin 1.07) harbored QTLs for both GY- and LR-related traits at stages I and II, respectively. These results help to understand the genetic basis of root development under field conditions and their contribution to grain yield.

Detection of QTL in multiple segregating families possesses many advantages over the classical QTL mapping in biparental populations. It has thus become increasingly popular, and different biometrical approaches are available to analyze such data sets. We empirically compared an approach based on linkage mapping methodology with an association mapping approach. To this end, we used a large population of 788 elite maize lines derived from six biparental families genotyped with 857 SNP markers. In addition, we constructed genetic maps with reduced marker densities to assess the dependency of the performance of both mapping approaches on the marker density. We used cross-validation and resample model averaging and found that while association mapping performed better under high marker densities, this was reversed under low marker densities. In addition to main effect QTL, we also detected epistatic interactions. Our results suggest that both approaches will profit from a further increase in marker density and that a cross-validation should be applied irrespective of the biometrical approach.

Folic acid and methylenetetrahydrofolate reductase (MTHFR) may affect the development of human cancer. However, few studies have evaluated folate intake and MTHFR in susceptibility to and prognosis of patients with ovarian cancer. We conducted a prospective case-control study in 215 ovarian cancer patients and 218 controls (all Chinese) between Jan. 2004 and Jan. 2007. MTHFR C677T genotyping was done by PCR-RFLP. All patients were followed up until Dec. 2010. We found a 2.43-fold increased risk of ovarian cancer among MTHFR 677TT carriers, and a decreased risk of ovarian cancer in individuals with high folate intake (OR = 0.54, 95% CI = 0.32–0.94). Cox regression survival analysis showed that among the ovarian cancer patients, those carrying the 677TT genotype had a higher risk of death (HR = 2.17, 95% CI = 1.20–4.79), while high folate intake was associated with a lower risk of death (HR = 0.43, 95% CI = 0.33–0.88). Moreover, MTHFR 677CC carriers with higher folate intake showed a lower risk of death from ovarian cancer (HR = 0.32, 95% CI = 0.27–0.82). In summary, high folate intake may lessen susceptibility and improve the prognosis of ovarian cancer patients, while the MTHFR 677TT genotype appears to increase ovarian cancer risk and worsen its prognosis in a Chinese population.

An approach to the enhancement of Cherenkov radiation source driven by two electron beams (TEBs) is presented in this paper. The Cherenkov radiation source is composed of a cylindrical grating, and TEBs with a velocity separation are concentric and separated. By a field matched method, the dispersion equation is derived with a linearized fluid theory and solved by numerical calculation. The numerical results show that a considerable enhancement of growth rate is realized at an optimized voltage ratio due to two stream instability. Moreover, with a help of 2-D particle-in-cell simulations, the improvement of output power induced by the two stream instability is demonstrated, and the decreased of output power is observed as the increased distance of two electron beams.

In solid-liquid systems, macroscopic solids lose their equilibrium and melt in a manner that results in overall movement of the solid-liquid interface. This phenomenon occurs when they are subjected to temperature gradients or external stress, for example. However, many experiments suggest that the melting of nano- and micro-sized metallic nuclei follows a different process not described by traditional melting theory. In this paper, we demonstrate through simulation that the melting of solid nuclei of these sizes occurs via random breaches at the interfaces. Moreover, this breaching process occurs at the exact solid-liquid equilibrium temperature and in the absence of any external disturbance, which suggests the name “self-instability” for this melting process. We attribute this spontaneous instability to the curvature of the samples; based on the relationship between the sample’s instability and its curvature, we propose a destabilizing model for small systems. This model fits well with experimental results and leads to new insights into the instability behavior of small-sized systems; these insights have broad implications for research topics ranging from dendrite self-fragmentation to nanoparticle instability.

This paper provides the results of an investigation on dietary intakes and internal doses of polycyclic aromatic hydrocarbons (PAHs) for nonsmoking women from Beijing, China. Concentrations of PAHs were measured by gas chromatography/mass spectrometry (GC/MS) for human milk, placenta, and umbilical cord blood samples from 40 nonsmoking women and for 144 composite food samples covering major food categories. Information on food consumption and estimated ingestion doses of PAHs by the cohort was also collected individually. Relationship among the studied human samples and relative importance of breastfeeding to the total exposure dose of infants were addressed. The median (mean and standard deviation) total concentrations of 15 PAHs in human milk, placenta, and umbilical cord blood with (or without) fat normalization were 278 (9.30 ± 5.75), 819 (35.9 ± 15.4), and 1370 (5.521 ± 3.71) ng/g of fat, respectively, and the corresponding levels of benzo[a]pyrene equivalent (B[a]P(equiv)) were 11.2 (0.473 ± 0.605), 16.2 (0.717 ± 0.318), and 13.1 (0.140 ± 0.225) ng/g of fat, respectively. The calculated intake of B[a]P(equiv) by Beijing cohort varied from 0.609 to 4.69 ng·kg(-1)·day(-1) with a median value of 1.93 (2.09 ± 0.921 mean ± standard deviation) ng·kg(-1)·day(-1). Significant correlations were found among human milk, placenta, and umbilical cord blood (p0.05) for low-molecular-weight PAHs, indicating selective transfer potential of individual PAHs from mother to fetus. Internal dose of PAHs was not in proportion to amounts of food ingestion, daily dietary intake, lifestyle, and social-demographic characteristics of the participants (p0.05). Ingested doses of PAHs (3.00-102 ng·kg(-1)·day(-1)), which were much higher than the inhaled doses (0.152-8.50 ng·kg(-1)·day(-1)), were 3-4 orders of magnitude lower than the recommended reference doses, unlikely to impose any obvious risk based on current knowledge.

This paper focuses on the control of bidirectional power flow in the electric shipboard power systems, especially in the Medium-Voltage Direct Current (MVDC) shipboard power system. Bidirectional power control between the main MVDC bus and the local zones can improve the energy efficiency and control flexibility of electric ship systems. However, since the MVDC system contains various nonlinear loads such as pulsed power load and radar in various subsystems, the voltage of the MVDC and the local zones varies significantly. This voltage variation affects the control performance of the bidirectional DC-DC converters as exogenous? disturbances. To improve the control performance regardless of uncertainties and disturbances, this paper proposes a novel controller design method of the bidirectional DC?C converters using L1 control theory and intelligent optimization algorithm. The performance of the proposed method is verified via large-scale real-time digital simulation of a notional shipboard MVDC power system.