Natural flyers and swimmers employ flexible wings or fins to propel. While the complex interaction between the foil with deformation and the surrounding non-steady fluid environment defines the propulsion performance of the propellers, elucidating the interaction mechanism through theoretical models earns much challenge. Based on elastokinetics and linear potential flow theory, this study proposes a simplified analytical model to clarify the kinematics and the propulsion performance of a flexible thin foil pitching in flow. The dynamical forces, including the inertial force of the foil and the non-steady fluid pressure, are used to determine the averaged deformation angle of the foil. Combining the averaged deformation angle and the prescribed driving pitching motion, the kinematics of the foil is resolved analytically. Based on the analytical expressions for the corresponding pitching motion, analytical relations among the physical parameters of the stiffness and the mass of the foil and the driving frequency are given to these critical conditions, including resonance of the flow–structure system, equal pitching amplitude between the flexible foil and the rigid counterpart, phase angle transition from ${\rm \pi}/2$ to $- {\rm \pi}/2$. Subsequently, the performance of the foil, including the thrust, the power and the propulsive efficiency, as a function of the flexibility of the foil are derived, together with the introduction of a bluff body type offset drag to the thrust. The formulated analytical theory, which matches nicely with previous reports, will help to interpret the effect of the flexibility and regulate the propulsive performance of the flexible foil when pitching in fluid.

High-molecular-weight glutenin subunit (HMW-GS) is a key factor affecting dough-processing quality. 1Sty13 is a novel HMW-GS found in the tetraploid species, Elymus sibiricus L. 1Sty13 has faster electrophoretic mobility than the 1Dy12 subunit on sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis. The gene encoding the 1Sty13 subunit was composed of 1803 nucleotide base pairs with an open reading frame that was 599 amino acids in length. Analysis of the predicted amino acid sequence of 1Sty13 indicated that the N-terminal domain was similar to the y-type subunit, whereas the C-terminal domains were similar to the x-type subunit. Five cysteine residues were found in 1Sty13, which is one less than the published HMW-GS in the St genome. The 1Sty13 protein was purified at a scale sufficient for incorporation into flour for the SDS sedimentation test, which indicated that incorporating 1Sty13 improved dough quality.

Leg weakness (LW) issues are a great concern for pig breeding industry. And it also has a serious impact on animal welfare. To dissect the genetic architecture of limb-and-hoof firmness in commercial pigs, a genome-wide association study was conducted on bone mineral density (BMD) in three sow populations, including Duroc, Landrace and Yorkshire. The BMD data were obtained by ultrasound technology from 812 pigs (including Duroc 115, Landrace 243 and Yorkshire 454). In addition, all pigs were genotyped using genome-by-sequencing and a total of 224 162 single-nucleotide polymorphisms (SNPs) were obtained. After quality control, 218 141 SNPs were used for subsequent genome-wide association analysis. Nine significant associations were identified on chromosomes 3, 5, 6, 7, 9, 10, 12 and 18 that passed Bonferroni correction threshold of 0.05/(total SNP numbers). The most significant locus that associated with BMD (P value = 1.92e−14) was detected at approximately 41.7 Mb on SSC6 (SSC stands for Sus scrofa chromosome). CUL7, PTK7, SRF, VEGFA, RHEB, PRKAR1A and TPO that are located near the lead SNP of significant loci were highlighted as functionally plausible candidate genes for sow limb-and-hoof firmness. Moreover, we also applied a new method to measure the BMD data of pigs by ultrasound technology. The results provide an insight into the genetic architecture of LW and can also help to improve animal welfare in pigs.

Varicella is an acute respiratory infectious diseases, with high transmissibility and quick dissemination. In this study, an SEIR (susceptible-exposed-infected-recovered) dynamic model was established to explore the optimal prevention and control measures according to the epidemiological characteristics about varicella outbreak in a school in a central city of China. Berkeley Madonna 8.3.18 and Microsoft Office Excel 2010 software were employed for the model simulation and data management, respectively. The result showed that the simulated result of SEIR model agreed well with the reported data when β (infected rate) equal to 0.067. Models showed that the cumulative number of cases was only 13 when isolation adopted when the infected individuals were identified (assuming isolation rate was up to 100%); the cumulative number of cases was only two and the TAR (total attack rate) was 0.56% when the vaccination coefficient reached 50%. The cumulative number of cases did not change significantly with the change of efficiency of ventilation and disinfection, but the peak time was delayed; when δ (vaccination coefficient) = 0.1, m (ventilation efficiency) = 0.7 or δ = 0.2, m = 0.5 or δ = 0.3, m = 0.1 or δ = 0.4 and above, the cumulative number of cases would reduce to one case and TAR would reduce to 0.28% with combined interventions. Varicella outbreak in school could be controlled through strict isolation or vaccination singly; combined interventions have been adopted when the vaccination coefficient was low.

Nanosilver is an environment-friendly, harmless alternative of traditional disinfectants which can be potentially applied in the sericulture industry. However, the effects of nanosilver on the intestinal bacterial community of the silkworms (Bombyx mori L.) are unclear. In this study, Illumina MiSeq high-throughput sequencing technology was used to assess the intestinal bacterial community in both male and female silkworms while treated with different concentrations of nanosilver. We found that nanosilver significantly influenced the composition of silkworm intestinal bacterial community on the different taxonomic levels. Most conspicuously, the abundance of Firmicutes was increased by the treatment of 20 mg L−1 nanosilver but decreased by that of 100 mg L−1 nanosilver at the phylum level. The same trend was observed in Bacilli at the class level and in Enterococcus at the genus level. In some extreme cases, application of nanosilver eliminated the bacterium, e.g., Brevibacillus, but increased the population of several other bacteria in the host intestine, such as Blautia, Terrisporobacter, Faecalibacterium, and some bacteria could only be found in nanosilver treatment groups, e.g., Dialister. In addition, although nanosilver generally showed negative effects on the cocooning rate in a dose-dependent manner, we found that 20 mg L−1 nanosilver treatment significantly increased the body weight of silkworms and did not show negative effects on the survival rate. These results indicated that the intestinal bacteria community of silkworm larvae was significantly changed after nanosilver treatment which might consequently influence host growth and development.

Maternal one-carbon metabolism during pregnancy is crucial for fetal development and programming by DNA methylation. However, evidence on one-carbon biomarkers other than folate is lacking. We, therefore, investigated whether maternal plasma methyl donors, that is, choline, betaine and methionine, are associated with birth outcomes. Blood samples were obtained from 115 women during gestation (median 26·3 weeks, 90 % range 22·7–33·0 weeks). Plasma choline, betaine, methionine and dimethylglycine were measured using HPLC-tandem MS. Multivariate linear and logistic regression models were used to estimate the association between plasma biomarkers and birth weight, birth length, the risk of small-for-gestational-age and large-for-gestational-age (LGA). Higher level of maternal betaine was associated with lower birth weight (–130·3 (95 % CI –244·8, –15·9) per 1 sd increment for log-transformed betaine). Higher maternal methionine was associated with lower risk of LGA, and adjusted OR, with 95 % CI for 1 sd increase in methionine concentration was 0·44 (95 % CI 0·21, 0·89). Stratified analyses according to infant sex or maternal plasma homocysteine status showed that reduction in birth weight in relation to maternal betaine was only limited to male infants or to who had higher maternal homocysteine status (≥5·1 µmol/l). Higher maternal betaine status was associated with reduced birth weight. Maternal methionine was inversely associated with LGA risk. These findings are needed to be replicated in future larger studies.

Massively parallel sequencing (MPS) technology has become increasingly available and has been widely used to screen for trisomies 21, 18, and 13 in singleton pregnancies. This study assessed the performance of MPS testing of cell-free fetal DNA (cffDNA) from maternal plasma for trisomies 21, 18, and 13 in twin pregnancies. Ninety-two women with twin pregnancies were recruited. The results were identified through karyotypes of amniocentesis or clinical examination and follow-up of the neonates. Fluorescent in-situ hybridization was used to examine the placentas postnatally in cases of false-positive results. The fetuses with autosomal trisomy 21 (n = 2) and trisomy 15 (n = 1) were successfully detected via MPS testing of cffDNA. There was one false-positive for trisomy 13 (n = 1), and fluorescence in-situ hybridization (FISH) identified confined placental mosaicism in this case. For twin pregnancies undergoing second-trimester screening for trisomy, MPS testing of cffDNA is feasible and can enhance the diagnostic spectrum of non-invasive prenatal testing, which could effectively reduce invasive prenatal diagnostic methods. In addition to screening for trisomy 21, 18, and 13 by cffDNA, MPS can detect fetal additional autosomal trisomy. False-positive results cannot completely exclude confined placental mosaicism.

Based on 15 diffusion couples located in face centered cubic single-phase region of ternary Ni–Al–Mo system, high-throughput determination of composition-dependent interdiffusivity matrices at 1273, 1373, and 1473 K was performed by using the recently developed numerical inverse method. The determined main interdiffusivities over the investigated composition and temperature ranges are all positive, and $\tilde D_{{\rm{AlAl}}}^{{\rm{Ni}}}$ is generally larger than $\tilde D_{{\rm{MoMo}}}^{{\rm{Ni}}}$ . Moreover, $\tilde D_{{\rm{AlAl}}}^{{\rm{Ni}}}$ generally increases with concentration of Al, while $\tilde D_{{\rm{MoMo}}}^{{\rm{Ni}}}$ increases with concentrations of both Al and Mo. In contrast, the cross interdiffusivities can be either positive or negative. Average relative errors of $\tilde D_{{\rm{AlAl}}}^{{\rm{Ni}}}$ , $\tilde D_{{\rm{AlMo}}}^{{\rm{Ni}}}$ , $\tilde D_{{\rm{MoAl}}}^{{\rm{Ni}}}$ , and $\tilde D_{{\rm{MoMo}}}^{{\rm{Ni}}}$ were evaluated to be 2.4, 5.1, 16.1, and 1.7% using error propagation. Furthermore, our prediction of composition profiles and interdiffusion fluxes based on evaluated interdiffusivity matrices agrees quite well with measured data. Traditional Matano–Kirkaldy method was also applied to further verify the reliability of obtained interdiffusivities. Besides, three-dimensional planes of activation energies of main interdiffusivities were also evaluated using the Arrhenius equation.

Choline and betaine are essential nutrients involved in one-carbon metabolism and have been hypothesised to affect breast cancer risk. Functional polymorphisms in genes encoding choline-related one-carbon metabolism enzymes, including phosphatidylethanolamine N-methyltransferase (PEMT), choline dehydrogenase (CHDH) and betaine-homocysteine methyltransferase (BHMT), have important roles in choline metabolism and may thus interact with dietary choline and betaine intake to modify breast cancer risk. This study aimed to investigate the interactive effect of polymorphisms in PEMT, BHMT and CHDH genes with choline/betaine intake on breast cancer risk among Chinese women. This hospital-based case–control study consecutively recruited 570 cases with histologically confirmed breast cancer and 576 age-matched (5-year interval) controls. Choline and betaine intakes were assessed by a validated FFQ, and genotyping was conducted for PEMT rs7946, CHDH rs9001 and BHMT rs3733890. OR and 95 % CI were estimated using unconditional logistic regression. Compared with the highest quartile of choline intake, the lowest intake quartile showed a significant increased risk of breast cancer. The SNP PEMT rs7946, CHDH rs9001 and BHMT rs3733890 had no overall association with breast cancer, but a significant risk reduction was observed among postmenopausal women with AA genotype of BHMT rs3733890 (OR 0·49; 95 % CI 0·25, 0·98). Significant interactions were observed between choline intake and SNP PEMT rs7946 (Pinteraction=0·029) and BHMT rs3733890 (Pinteraction=0·006) in relation to breast cancer risk. Our results suggest that SNP PEMT rs7946 and BHMT rs3733890 may interact with choline intake on breast cancer risk.

Understanding crop water use in mixed crops over sole cropping is vital for developing optimum water management systems for crop production. In this study, a two-year field experiment with typical maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] relay strip intercropping (2:2 maize-to-soybean rows; 200 cm bandwidth) was carried out in the 2013 and 2014 growing seasons. The quantitative effects of various planting patterns on the water-use efficiency (WUE) and water distribution were investigated. Our results indicated that soil volumetric water content and soil evaporation in the intercropping systems showed decreasing trends in the order: maize row (MM) < maize-to-soybean row (MS) < soybean row (SS). The highest leaf transpiration (1.91 and 2.07 mmol m−2 s−1) for the intercropped maize was measured in each of the two years in the 20 cm maize narrow-row planting pattern and decreased thereafter. Opposite trend was observed for the intercropped soybean; the highest soybean leaf transpiration (7.01 and 6.80 mmol m−2 s−1 for 2013 and 2014, respectively) was recorded in the 70 cm. The WUE of maize and soybean intercrops was lower than that of sole crop counterparts. However, the maximum group water use efficiency (GWUE) of 26.08 and 26.20 kg ha−1 mm−1 in the 40–50 cm maize narrow-row planting pattern was, respectively, 39.6% and 23% higher compared with that of sole crops. The water equivalent ratio (WER) values ranged from 1.60–1.79, suggesting better crop water use in the intercrops over sole cropping. Planting patterns provided by 40–50 cm maize narrow-row spacing were considered the most efficient in terms of maximum total yields, GWUE and WER. These results suggest that an appropriate reduction in the spacing of narrow maize row with wide soybean row could be an efficient crop management method to achieve optimal WUE and homogeneous water distribution in maize–soybean intercropping systems.

The six-legged robot Octopus is designed for nuclear disaster relief missions. When the robot suffers from failures, its performance can be significantly affected. Thus, fault tolerance is essential for walking and operating in environments inaccessible to humans. The current fault-tolerant gaits for legged robots usually either initially lock the entire broken leg or just abandon the broken leg, but then fail to take full advantage of the normal actuators on the broken leg and add extra constraints. As the number of broken legs increases, the robot will no longer be able to walk using the existing fault-tolerant gaits. To solve this problem, screw theory is used for analyzing the remaining mobility after failure. Based on the analysis, a method of motion planning through fault-tolerant Jacobian matrices, which are linear, is presented. This method can enable the robot to accomplish desired movement using broken legs along with other certain concomitant motions as compensation. Finally, experiments and simulations of multiple faults demonstrate the real effects on the Octopus robot.

Previous epidemiological studies have revealed the anti-cancer effect of dietary circulating carotenoids. However, the protective role of specific individual circulating carotenoids has not been elucidated. The purpose of this study was to examine whether serum carotenoids, including α-carotene, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin, could lower the risk for breast cancer among Chinese women. A total of 521 women with breast cancer and age-matched controls (5-year interval) were selected from three teaching hospitals in Guangzhou, China. Concentrations of α-carotene, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin were measured using HPLC. Unconditional logistic regression models were used to calculate OR and 95 % CI using quartiles defined in the control subjects. Significant inverse associations were observed between serum α-carotene, β-carotene, lycopene, lutein/zeaxanthin and the risk for breast cancer. The multivariate OR for the highest quartile of serum concentration compared with the lowest quartile were 0·44 (95 % CI 0·30, 0·65) for α-carotene, 0·27 (95 % CI 0·18, 0·40) for β-carotene, 0·41 (95 % CI 0·28, 0·61) for lycopene and 0·26 (95 % CI 0·17, 0·38) for lutein/zeaxanthin. However, no significant association was found between serum β-cryptoxanthin and the risk for breast cancer. Stratified analysis by menopausal status and oestrogen receptor (ER)/progesterone receptor (PR) showed that serum α-carotene, β-carotene, lycopene and lutein/zeaxanthin were inversely associated with breast cancer risk among premenopausal women and among all subtypes of ER or PR status. The results suggest a protective role of α-carotene, β-carotene, lycopene and lutein/zeaxanthin, but not β-cryptoxanthin, in breast cancer risk.

This study was conducted to determine the effects of l-carnitine (LC), as an antioxidant, in preventing spermatozoa damage during the freezing–thawing process in both astheno- and normozoospermic human semen samples. Seventy semen samples (37 asthenozoospermic and 33 normozoospermic) were involved in this study. Cryopreservation medium supplemented with 1.0 g/l LC was mixed with semen at a ratio of 1:1 (v/v). Controls were cryopreserved with freezing medium only. Assessment of motility, viability (VIA), mitochondrial membrane potential (MMP) and DNA fragmentation index (DFI) were performed on aliquots of fresh semen, frozen–thawed control and frozen–thawed LC treated samples. Supplementation of the cryopreservation medium with LC induced a significant improvement in post-thaw sperm parameters in both the asthenozoospermic and normozoospermic semen samples, compared with those of the control, regarding sperm fast forward motility, forward motility, total motility and VIA. LC showed better protective effects towards asthenozoospermia for DFI (F = 115.85, P < 0.01) and VIA (F = 67.14, P < 0.01) than did normozoospermic semen samples. We conclude that supplementation with LC prior to the cryopreservation process reduced spermatozoa cryodamage in both asthenozoospermic and normozoospermic semen samples. LC had better protective effects for asthenozoospermic human semen samples. Future research should focus on the molecular mechanism for and the different protective effects of LC between asthenozoospermic and normozoospermic semen samples during cryopreservation.

Fault tolerance is a very important issue for legged robots, especially in some harsh environments. One of the most fragile parts is the actuation system. There are two common faults of robot actuators: (1) the motor is locked and could not move anymore; (2) the motor is uncontrollable and can be treated as a passive joint. In this paper, we first discuss all fault combinations of a single leg of a hexapod walking robot with parallel-parallel mechanism topology. Then, the leg tolerable criterion is brought out, which defines whether a leg is fault tolerant. After that, the fault tolerance of the whole robot is researched, and we found that the robot can walk with one tolerable leg or two opposite tolerable legs. Finally, relative simulation results are given, which show the robot walk with one or two broken legs.

In an attempt to study the thermal transport at the interface between nanotubes and graphene, vertically aligned multiwalled carbon nanotubes (CNTs) were grown on graphite thin film substrates. A systematic cross-sectional probing of the materials’ morphology of the interface by scanning electron microscopy and high-resolution transmission electron microscopy revealed that an excellent bond existed between the nanotubes and the substrate along some fraction of interface. Imaging and electron diffraction analyses performed at the boundary reveal a polycrystalline interfacial structure. Compositional probing along the interface by energy dispersive x-ray spectroscopy revealed that there were no catalyst particles or other impurities present. The estimated interfacial thermal resistance of lower than 5–7.5 (mm2K)/W suggests that this type of CNT/graphite interface could open up multiple routes toward the designing and development of advanced thermal interface materials for aerospace and nano-/microelectronics applications.

Twins could play a crucial role in our understanding of genetic contributions to numerous etiologically complex disorders. In China, although adult twins are relatively rare, twins will become increasingly available due to increasing twin birth rates. Thus, child twin data will be a valuable resource to contribute to the field of child and adolescent psychopathology. The first twin database of children aged from 6 to 16 was established in Chongqing, R.P., China. In this article, we will discuss our experiences in establishing the twin database, completed in three steps — the first step being to search and identify twins, the second being to keep contact with the twins and the final being to seek cooperation with the twin families, and its future prospects. Our twin database has proven to be an efficient method for the investigation and data collection of twin children in China. The results of our present study suggest that the inclusion of twin information in the residence registration of the public security bureaus in the future may ensure a smooth run of research based on the demographic resources. We propose that school networks may be adopted as the preferred method of collection of twin records for future studies.