In certain scenarios, the large footprint of a robot is not conducive to multi-robot cooperative operations. This paper presents a generalized single-loop parallel manipulator with remote center of motion (GSLPM-RCM), which addresses this issue by incorporating a reconfigurable base. The footprint of this RCM manipulator can be adjusted by varying the parameters of the reconfigurable base. First, utilizing configuration evolution, a reconfigurable base is constructed based on the principle of forming RCM motion. Then, according to the modular analysis method, the inverse kinematics of this parallel RCM manipulator is analyzed, and the workspace is also analyzed. Subsequently, the motion/force transmissibility of this RCM manipulator is analyzed by considering its single-loop and multi-degree of freedom characteristics. Leveraging the workspace index and transmissibility indices, dimension optimization of the manipulator is implemented. Finally, the influence of the reconfigurable base on the workspace and the transmissibility performance of the optimized manipulator is studied.

Digitaria ciliaris var. chrysoblephara (Fig. & De Not.) R.R. Stewart is an annual xeromorphic weed that severely infests direct-seeded rice fields in China. Herbicide resistance is emerging in D. ciliaris var. chrysoblephara owing to extensive and recurrent use of the acetyl-CoA carboxylase (ACCase)-inhibiting herbicide metamifop. In this study, a total of 53 D. ciliaris var. chrysoblephara populations randomly sampled from direct-seeded rice fields across Jiangsu Province were investigated for metamifop resistance and potential resistance-endowing mutations. Single-dose assays revealed that 17 (32.1%) populations evolved resistance to metamifop and 5 (9.4%) populations were in the process of developing resistance. The resistance index (RI) of metamifop-resistant populations ranged from 2.7 to 32.1. Amino acid substitutions (Ile-1781-Leu, Trp-2027-Cys/Ser, and Ile-2041-Asn) in ACCase genes were detected in resistant D. ciliaris var. chrysoblephara plants and caused various cross-resistance patterns to ACCase-inhibiting herbicides. All of four resistant populations (YC07, YZ09, SQ03, and HA06), with different ACCase mutations, exhibited cross-resistance to the aryloxyphenoxypropionate (APP) herbicides cyhalofop-butyl (RI values: 10.0 to 19.9), fenoxaprop-P-ethyl (RI values: 53.7 to 132.8), and haloxyfop-P-methyl (RI values: 6.2 to 62.6), and the phenylpyrazoline (DEN) pinoxaden (RI values: 2.3 to 5.4), but responded differently to the cyclohexanedione (CHD) herbicides clethodim and sethoxydim. It is noteworthy that four postemergence herbicides used for rice cropping, including bispyribac-sodium, pyraclonil, quinclorac, and anilofos, showed poor control effect against D. ciliaris var. chrysoblephara, suggesting few alternations for managing this weed in rice fields except ACCase inhibitors. In conclusion, this work demonstrated that the D. ciliaris var. chrysoblephara had developed resistance to ACCase-inhibiting herbicides in rice cultivation of China, and target-site amino acid substitutions in ACCase were primarily responsible for metamifop resistance.

The incidence of scarlet fever has increased dramatically in recent years in Chongqing, China, but there has no effective method to forecast it. This study aimed to develop a forecasting model of the incidence of scarlet fever using a seasonal autoregressive integrated moving average (SARIMA) model. Monthly scarlet fever data between 2011 and 2019 in Chongqing, China were retrieved from the Notifiable Infectious Disease Surveillance System. From 2011 to 2019, a total of 5073 scarlet fever cases were reported in Chongqing, the male-to-female ratio was 1.44:1, children aged 3–9 years old accounted for 81.86% of the cases, while 42.70 and 42.58% of the reported cases were students and kindergarten children, respectively. The data from 2011 to 2018 were used to fit a SARIMA model and data in 2019 were used to validate the model. The normalised Bayesian information criterion (BIC), the coefficient of determination (R2) and the root mean squared error (RMSE) were used to evaluate the goodness-of-fit of the fitted model. The optimal SARIMA model was identified as (3, 1, 3) (3, 1, 0)12. The RMSE and mean absolute per cent error (MAPE) were used to assess the accuracy of the model. The RMSE and MAPE of the predicted values were 19.40 and 0.25 respectively, indicating that the predicted values matched the observed values reasonably well. Taken together, the SARIMA model could be employed to forecast scarlet fever incidence trend, providing support for scarlet fever control and prevention.

The dipeptide dl-methionyl-dl-methionine (Met-Met) has extremely low water solubility and better absorption than other methionine sources (such as dl-methionine and l-methionine) available in the market. Therefore, six diets (D1, D2, D3, D4, D5 and D6) containing 0, 0·07, 0·15, 0·21, 0·28 and 0·38 % Met-Met were formulated to investigate the effects of Met-Met in juvenile Nile tilapia, Oreochromis niloticus (17 g initial body weight). The results indicated that percentage weight gain and specific growth rate of fish fed with D2 and D3 diets were higher than those fed with D1, D4–D6 diets. The levels of total essential amino acid in whole body of fish fed with D3 and D4 diets were significantly higher than those fed the D1 diet. Superoxide dismutase activity and malondialdehyde content have no significant difference in fish fed the diet with or without Met-Met supplementation. Majority of reads derived from the fish intestine belonged to members of Fusobacteria, followed by Bacteroidetes and Proteobacteria. Diversity of intestinal microbiota and total antioxidant capacity in fish fed with D3 diet was significantly higher than that of other groups. Based on the growth results, the authors conclude that the optimal level of Met is 0·61 % Met with the addition of 0·15 % Met-Met for grower-phase O. niloticus.

Organic food products, which have been sold traditionally at natural food stores, have become increasingly available through mass marketing channels. This study estimated an almost ideal demand system (AIDS) model using 2008–2010 retail scanner data to examine consumer demand for organic fluid milk products sold at conventional and natural marketing channels. Asymmetric cross-price elasticities were found suggesting relative stickiness in demand to switch from organic milk to conventional milk and from natural stores to food, drug, and mass merchandiser stores. More generally, demands shifting toward products with higher expenditure elasticities in a differentiated market can be explained by relative budget shares and expenditure elasticities.

Four isonitrogenous and isoenergetic purified diets containing free arachidonic acid (ARA) or EPA (control group), 0·30 % ARA, 0·30 % EPA and 0·30 % ARA+EPA (equivalent) were designed to feed juvenile grass carp (10·21 (sd 0·10) g) for 10 weeks. Only the EPA group presented better growth performance compared with the control group (P<0·05). Dietary ARA and EPA were incorporated into polar lipids more than non-polar lipids in hepatopancreas but not intraperitoneal fat (IPF) tissue. Fish fed ARA and EPA showed an increase of serum superoxide dismutase and catalase activities, and decrease of glutathione peroxidase activity and malondialdehyde contents (P<0·05). The hepatopancreatic TAG levels decreased both in ARA and EPA groups (P<0·05), accompanied by the decrease of lipoprotein lipase (LPL) activity in the ARA group (P<0·05). Fatty acid synthase (FAS), diacylglycerol O-acyltransferase and apoE gene expression in the hepatopancreas decreased in fish fed ARA and EPA, but only the ARA group exhibited increased mRNA level of adipose TAG lipase (ATGL) (P<0·05). Decreased IPF index and adipocyte sizes were found in the ARA group (P<0·05). Meanwhile, the ARA group showed decreased expression levels of adipogenic genes CCAAT enhancer-binding protein α, LPL and FAS, and increased levels of the lipid catabolic genes PPARα, ATGL, hormone-sensitive lipase and carnitine palmitoyltransferase 1 (CPT-1) in IPF, whereas the EPA group only increased PPARα and CPT-1 mRNA expression and showed less levels than the ARA group. Overall, dietary EPA is beneficial to the growth performance, whereas ARA is more potent in inducing lipolysis and inhibiting adipogenesis, especially in IPF. Meanwhile, dietary ARA and EPA showed the similar preference in esterification and the improvement in antioxidant response.

A “RE-free” and I-phase-containing Mg–8Sn-based alloy system was developed and successfully fabricated through the equal channel angular pressing (ECAP) process. The influence of the Zn/Al mass ratio on the microstructures and mechanical properties of the as-ECAPed Mg–8Sn–(5,6,7)Zn–2(wt%)Al alloys was investigated using an optical microscope, an X-ray diffractometer, a scanning electron microscope, a transmission electron microscope, and a universal testing machine. Grain size, dynamic recrystallization behavior, and texture were found to be greatly affected by the Zn/Al mass ratio. Furthermore, the ultimate tensile strength (250 MPa) and elongation (14.5%) of the alloy with a Zn/Al mass ratio of 3 were considerably increased compared to those of the as-ECAPed alloys with Zn/Al ratios of 2.5 and 3.5 (ultimate tensile strength and elongation of 215 MPa and 13% and 184 MPa and 10%, respectively). This significant enhancement was attributed to extensive grain boundary strengthening, precipitation strengthening, and higher work hardening capacity as well as texture randomization. The strength and ductility of the as-ECAPed alloys are also discussed in terms of the I-phase and Mg2Sn formation.

The composite Li-ion battery anode material of Fe2SiO4, Fe3O4, Fe3C (Fe-Si-O) and carbon nanotubes was prepared by a simple one-step reaction between ferrocene and tetraethyl orthosilicate. When cycled at 100 mA g-1, this material exhibited ever-increasing capacities and reached 588 mAh g-1 at the 280th cycle. At 500 mA g-1, a reversible capacity of 350 mAh g-1 was retained for 600 cycles. Compared with Fe3O4 materials, the Fe-Si-O/CNT exhibited superior long-term high-rate performance, which could mainly result from its enhanced stability and conductivities by introducing silicates and CNTs during the one-step synthesis.

The TiO2 hollow spheres (TiO2HS) were successfully prepared by a hydrothermal method and added to Vulcan XC-72 carbon black as the support materials for Pd nanoparticles. A facile approach to promote ethylene glycol (EG) electrooxidation in alkaline medium was carried out by the PdBi/TiO2HS-C catalyst. The results show that Pd and Bi nanoparticles are uniformly dispersed on the surface of carbon-doped TiO2 hollow spheres, the appropriate amount of Bi modification into Pd/TiO2HS-C catalyst can enhance remarkably the electrocatalytic activity for EG oxidation, in which the PdBi/TiO2HS-C (Pd:Bi = 1:0.1) catalyst exhibits excellent stability. The high electrochemical performance is attributed to the unique structure and high surface area of the TiO2HS, metal nanoparticles uniform distribution, the electronic effect between Pd and Bi as well as the bifunctional effect between metal nanoparticles and the support TiO2HS-C. The results obtained are significant for the development of new Pd-based TiO2HS-C electrocatalysts for alcohol fuel cells.

This paper examines grocery retailers' ability to influence prices charged to consumers and paid to suppliers. We discuss how retailer market power manifests itself in terms of pricing and marketing strategies by setting forth and offering evidence in support of eight “stylized facts” of retailer pricing and brand decisions. We argue that little, if any, of this behavior can be explained by a model of a competitive, price-taking retailer, but that most of the indicated behavior was also inconsistent with traditional models of market power. Finally, we discuss the impacts of aspects of this retailer behavior on the upstream farm sector.

Penaeus monodon (mean initial wet weight 1·19 (se 0·01) g) were fed seven diets in triplicate: a control diet (D1) without carotenoids; three diets formulated to supply 0·1 % astaxanthin alone (D2), 0·2 % astaxanthin alone (D3), and a combination of 0·1 % astaxanthin and 1 % cholesterol (D4); three diets with 0·07 % canthaxanthin alone (D5), 0·13 % canthaxanthin alone (D6), and a combination of 0·07 % canthaxanthin and 1 % cholesterol (D7). Weight gain (WG, %), specific growth rate (SGR, %/d) and survival were chosen as parameters of shrimp growth performance. Total antioxidant status (TAS), superoxide dismutase (SOD), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were chosen as indices of shrimp plasma antioxidant capacity. Meanwhile, digestibility, retention efficiency and tissue carotenoids were also investigated to determine the additive effect of cholesterol on the efficiency of astaxanthin and canthaxanthin. After 74 d rearing, WG and SGR of shrimp fed D2–D4 and D7 were higher than those of shrimp fed D1 (P < 0·05). Shrimp fed D4 had the highest survival. The apparent digestibility coefficients (ADC) of astaxanthin in D2–D4 were higher than those of canthaxanthin in D5–D7 (P < 0·05). Although ADC of astaxanthin were quite high (>98 %) in D2–D4 and no differences were found among them (P>0·05), the carotenoid retention efficiencies in the whole body, muscle and shell (D2–D3 treatments) were considerably low; however, cholesterol supplementation significantly improved the carotenoid retention efficiencies in the whole body, muscle and shell (D4 treatment). Accordingly, the addition of cholesterol also significantly enhanced the carotenoid contents of tissues. Shrimp fed supplemented carotenoid diets (D2–D7) had higher TAS and lower SOD, ALT and AST than shrimp fed D1 (P < 0·05). A low dissolved oxygen stress test was conducted for 7 d after the rearing trial and shrimp survival was also compared among the treatments. The survival of shrimp fed the diets supplemented with astaxanthin or canthaxanthin was higher than that of shrimp fed D1 during the stress test (P < 0·05). In conclusion, all data suggested that astaxanthin was better than canthaxanthin as the dietary carotenoid source in the commercial diet of P. monodon, and the supplement of cholesterol could positively enhance the efficiency of astaxanthin and canthaxanthin.

We investigated whether the hypolipidaemic effect of fenofibrate and fasting observed in most omnivorous mammals may also apply to herbivorous fish. Grass carp (Ctenopharyngodon idella) fed a high-fat (8 %) diet exhibited a marked increase in blood lipids and body fat after 6 weeks. They were then treated with fenofibrate (100 mg/kg body weight) in the same high-fat diet for 2 weeks, followed by fasting for 1 week. Plasma lipid concentration, body fat amount, fatty acid composition, plasma thiobarbituric acid-reactive substances and some parameters related to hepatic fatty acid oxidation were measured, and liver samples were stained for histological examination. Fenofibrate treatment decreased TAG and cholesterol concentrations in plasma, total lipids of the whole body and liver, and EPA and DHA contents in tissues. Further, a mobilisation of mesenteric fat concomitant with an increase in hepatic peroxisomal fatty acid oxidation and lipid peroxidation was observed. Compared with fenofibrate treatment, fasting decreased body weight and plasma TAG, but not plasma cholesterol. It also reduced the fat content of the whole body and increased the EPA and DHA contents in the liver and other tissues. Fatty acid oxidation was stimulated by fasting in mitochondria, but not in peroxisomes. These data suggest that fenofibrate and fasting regulate the lipid metabolism in grass carp through different metabolic pathways. The grass carp is moderately responsive to a fibrate derivative in comparison with the well-known excess responsiveness of the rat model, and so it could be used for the study of lipid abnormalities as a herbivorous model.

High-fat diets may have favourable effects on growth of some carnivorous fish because of the protein-sparing effect of lipids, but high-fat diets also exert some negative impacts on flesh quality. The goal of the study was therefore to determine the effects of fat-enriched diets in juvenile grass carp (Ctenopharyngodon idella) as a typical herbivorous fish on growth and possible lipid metabolism alterations. Three isonitrogenous diets containing 2, 6 or 10% of a mixture of lard, maize oil and fish oil (1:1:1, by weight) were applied to fish for 8 weeks in a recirculation system. Data show that feeding diets with increasing lipid levels resulted in lowered feed intake, decreased growth and feed efficiency, and increased mesenteric fat tissue weight. Concomitantly, alteration of lipoprotein synthesis and greater level of lipid peroxidation were apparent in blood. In liver, muscle and mesenteric fat tissue, the percentages of α-linolenic acid and DHA were significantly increased or tended to increase with higher dietary lipid levels. Biochemical activity measurements performed on liver showed that, with the increase in dietary lipid level, there was a decrease in both mitochondrial and peroxisomal fatty acid oxidation capacities, which might contribute, at least in part, to the specific accumulation of α-linolenic acid and DHA into cells more active in membrane building. On the whole, grass carp have difficulty in energetically utilising excess dietary fat, especially when enriched in n−3 PUFA that are susceptible to peroxidation.

Two hundred and forty bacterial strains were isolated from three potato (Solanum tuberosum) cultivars from eight different sources. On the basis of antagonistic bacteria examination in vitro, greenhouse and field tests, 22.9% of isolated bacteria were endophytic and antagonistic. Three strains, namely A-10', T3 (Bacillus sp.) and H1-6 (Pseudomonas fluorescens), were chosen for their suppressive effect on bacterial ring rot (Clavibacter michiganensis subsp. sepedonicus) and their growth promotion. The strain A-10' was an endophytic bacterium with the effects of colonization, plant growth promotion and suppression of the pathogenic bacteria, showing good prospects for commercial use.