Zn is an important trace element involved in various biochemical processes in aquatic species. An 8-week rearing trial was thus conducted to investigate the effects of Zn on juvenile largemouth bass (Micropterus salmoides) by feeding seven diets, respectively, supplemented with no Zn (Con), 60 and 120 mg/kg inorganic Zn (Sul60 and Sul120), and 30, 60, 90 and 120 mg/kg organic Zn (Bio30, Bio60, Bio90 and Bio120). Sul120 and Bio120 groups showed significantly higher weight gain and specific growth rate than Con group, with Bio60 group obtaining the lowest viscerosomatic index and hepatosomatic index. 60 or 90 mg/kg organic Zn significantly facilitated whole body Zn retention. Up-regulation of hepatic superoxide dismutase, glutathione peroxidase and catalase activities and decline of malondialdehyde contents indicated augmented antioxidant capacities by organic Zn. Zn treatment also lowered plasma aminotransferase levels while promoting acid phosphatase activity and hepatic transcription levels of alp1, acp1 and lyz-c than deprivation of Zn. The alterations in whole body and liver crude lipid and plasma TAG contents illustrated the regulatory effect of Zn on lipid metabolism, which could be possibly attributed to the changes in hepatic expressions of acc1, pparγ, atgl and cpt1. These findings demonstrated the capabilities of Zn in potentiating growth and morphological performance, antioxidant capacity, immunity as well as regulating lipid metabolism in M. salmoides. Organic Zn could perform comparable effects at same or lower supplementation levels than inorganic Zn, suggesting its higher efficiency. 60 mg/kg supplementation of organic Zn could effectively cover the requirements of M. salmoides.

Listeriosis is a rare but serious foodborne disease caused by Listeria monocytogenes. This matched case–control study (1:1 ratio) aimed to identify the risk factors associated with food consumption and food-handling habits for the occurrence of sporadic listeriosis in Beijing, China. Cases were defined as patients from whom Listeria was isolated, in addition to the presence of symptoms, including fever, bacteraemia, sepsis and other clinical manifestations corresponding to listeriosis, which were reported via the Beijing Foodborne Disease Surveillance System. Basic patient information and possible risk factors associated with food consumption and food-handling habits were collected through face-to-face interviews. One hundred and six cases were enrolled from 1 January 2018 to 31 December 2020, including 52 perinatal cases and 54 non-perinatal cases. In the non-perinatal group, the consumption of Chinese cold dishes increased the risk of infection by 3.43-fold (95% confidence interval 1.27–9.25, χ2 = 5.92, P = 0.02). In the perinatal group, the risk of infection reduced by 95.2% when raw and cooked foods were well-separated (χ2 = 5.11, P = 0.02). These findings provide important scientific evidence for preventing infection by L. monocytogenes and improving the dissemination of advice regarding food safety for vulnerable populations.

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.

Change mode and effects analysis (CMEA) is a powerful technique for measuring product flexibility toward future changes and diminishing the cost of redesign as well as shortening time to market. As a systematic methodology, it provides an in-depth view for the investigation of potential changes, causes, and effects in designs, products, and processes. Traditional CMEA determines the risk priorities of change modes by using change potential number, which requires the risk factors of design flexibility, occurrence, and readiness to be precisely evaluated. However, this is not always possible in real applications due to the uncertainty and subjectivity involved in the early design stages. It has been criticized much for its deficiencies in criteria weighting of the risk factors, change potential number calculation, and risk priorities determination of the change modes. This paper presents a systematic evaluation approach for determining a more rational rank of change modes by combining with the entropy weight method, rough number, and grey relational analysis. In this study, the entropy weight method is adopted to calculate the relative importance of risk factors. Rough number is presented to aggregate individual weights and preferences, and to manipulate the vagueness in the evaluation process. Then a rough number enhanced grey relational analysis is proposed to evaluate the risk ranking of change modes. Finally, a practical example is put forward to validate the performance of the proposed method. The result shows that the proposed change mode evaluation method can effectively overcome the shortcomings of traditional CMEA and strengthen the objectivity of product flexibility measurement.

The mutualism between fig trees and their wasp pollinators is a model system for many ecological and evolutionary studies. However, the immature stages of pollinating fig wasps have rarely been studied. We monitored developing fig wasps of known ages and performed a series of dissections at 24 h intervals to identify key developmental traits of Ceratosolen solmsi marchali Mayr (Hymenoptera: Agaonidae), a pollinator of Ficus hispida L. (Moraceae). We identified where in the Ficus ovary eggs were deposited and time to hatch. We were also able to identify the timing and key underlying characters of five larval instars, three sub-pupal stages, and a single prepupal stage. We provide detailed morphological descriptions for the key stages and report some behavioral observations of the wasps in the several developmental stages we recorded. Scanning electron microscope images were taken.

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.

Different migration scenario of two giant planets may play a major role in forming the diverse resonant planetary configurations. The studies on the HD 128311 and HD 73526 systems show that two gas giants are captured in a 2:1 resonance but not in apsidal corotation, because one of the resonant argument circulates over the dynamical evolution. Herein we explore potential scenarios to produce the 2:1 librating-circulating resonance configuration. In the simulations, we find that both colliding or scattering events at early stage of dynamical evolution can induce the configurations trapped into resonance. In this sense, the librating-circulating resonance configuration is more likely to form by a hybrid mechanism of scattering and collision.

A 3-year study of spotted fever group rickettsial ecology in Inner Mongolia revealed that nearly half of the human population tested had antibodies to Rickettsia sibirica detected by complement fixation test. Infected persons, ticks and a high proportion of seropositive livestock and wild rodents were found in all five vegetation zones (desert, steppe, forest, forest-grassland and grassland).

Epidermal growth factor receptor (EGFR) is becoming a perfect target for killing carcinoma cells, especially because of its overexpression on the surface of these cells. Cationic antimicrobial peptides (CAP) have their own special mechanism of membrane-lytic cytotoxicity. In this study, a membrane-lytic immunotoxin (IT), chimeric protein MEGFMEL, was constructed to kill carcinoma cells with EGFR overexpression. This protein is composed of mouse (Mus musculus) epidermal growth factor (MEGF), as the target part, and melittin (MEL), as the cytotoxic part. Using Escherichia coli BL21 and pET30a as expression strain and vector, respectively, 63.45 μg/ml of MEGFMEL (68% purity) was obtained through low-temperature induction of expression and a thawing-freezing purification procedure (without cytolysis). In vitro activity measurement showed that this MEGFMEL significantly induced a lethal effect on A431 carcinoma cells overexpressing EGFR on the surface, with an LD50 value 52.6 μg/ml. The results suggest that the use of CAP as the toxin in the construction of unique membrane-lytic ITs aimed at EGFR is feasible.