: The individual and interactive effects of green tea (GT) extract and sodium nitrite (NT) on lipolysis and lipid oxidation were investigated in pepperoni during processing and storage (4 °C). ...Pepperoni was treated with GT at concentrations of 0.02%, 0.05%, 0.1%, 0.2%, 0.5%; and NT from 0.003% to 0.015% in increments of 0.003%; and a combination of 0.05% GT and 0.009% NT (GT/NT). The pH, color, residual nitrite, fatty acid (FA), and 2‐thiobarbituric acid reactive substances (TBARS) values were measured. The results showed inhibitory effects on TBARS value were concentration dependent. The largest effect was at 0.05% for GT and 0.009% for NT. Adding 0.05% GT significantly decreased (P < 0.05) the TBARS values but did not affect color values during storage. NT (0.009%) was more effective than GT (0.05%) for maintaining lower TBARS values (P < 0.05). Total fatty acids were not affected by 0.05% GT and 0.009% NT treatments. However, adding GT/NT showed a significant prooxidant effect (P < 0.05) in pepperoni, which accelerated lipolysis and lipid oxidation significantly (P < 0.05) during storage, with depletion of nitrite. This suggests that adding GT and an appropriate amount of NT into pepperoni could promote lipolysis and lipid oxidation during storage, as compared to NT alone.
Practical Application: When using GT extract as an antioxidant in industrial production of pepperoni, the interaction effect with NT should be considered, as it may lead to a prooxidant effect during refrigerated storage.
•Water consumption and economic profits of maize production under different irrigation methods and water levels were evaluated in an arid area.•Lower Ky under drip irrigation indicates the lesser ...reduction in yield caused by the declined ETc than furrow irrigation.•Drip irrigation had the higher water consumption coefficient in maize’s R3-R6 stages than border and furrow irrigations.•Drip irrigation with SMP threshold of −30 kPa or 360-mm furrow irrigation is recommended.
Water scarcity is everywhere and more prominent in arid and semi-arid regions. Moreover, water allocation for irrigation is hit by other economic sectors for low per capita profit. It is inevitable to extend higher-efficient irrigations to replace conventional border irrigation. A three-year field experiment was conducted to examine the effects of different irrigation methods on maize’s water use and economics in the Hetao Irrigation District of China. Taking 525-mm border irrigation as the control, furrow and drip irrigations at three water levels were implemented. Furrow irrigation included 100 % (450 mm), 80 % (360 mm) and 60 % (270 mm) of the recommended level, while three threshold values of soil matric potential: −10 kPa, −30 kPa, and −50 kPa, were used to trigger drip irrigation. The grain yield, ETc (water consumption for the whole growing season), ETcs (water consumption during a special growth stage), and water productivity were affected significantly by the irrigation methods and water levels. The average ETc of border, furrow and drip irrigations was 537.4 mm, 401.8–514.4 mm, and 306.6–496.2 mm for different levels, respectively. On average 10 % of the irrigation water was lost through deep percolation under border irrigation, while 10.5–29.0 mm of groundwater contributed to ETc under drip irrigation with −50 kPa. The higher Kwc (water consumption coefficient) was observed in R3-R6 (Milk-Maturity) stages under drip than border and furrow irrigations. The lower Ky (yield response factor) of drip (0.68) than furrow (0.82) indicated the lesser reduction in yield induced by the decreased ETc under drip irrigation. The 360-mm furrow irrigation obtained a comparable grain yield and net profit with the control, but reduced water application by 31 %. Drip irrigation at −30 kPa enhanced yield by 15 %, increased net profit by 23 %, and reduced water application by 57 %. Thus, drip irrigation at −30 kPa is recommended as the priority to replace border irrigation for maize production in the study area. If drip irrigation is unavailable, a 360-mm furrow irrigation is also an alternative to reduce water application without compromising benefit.
Water shortage and excessive chemical fertilizers application result in low soil water and nutrient availability and limit crop production in the Loess Plateau of Northwest China. Ammoniated straw ...incorporation with N fertilization may be an efficient strategy to maintain agricultural sustainability. However, the interactive effects of straw incorporation and N fertilizer on the biomass water use efficiency (WUE) in the winter wheat–summer maize rotation system remain unclear. A 3-year field experiment was conducted to evaluate the effects of combining ammoniated straw incorporation and N fertilizer on soil water, biomass yield and biomass water use efficiency (WUE) in an annual summer maize (Zea mays L.)—Winter wheat (Triticum aestivum L.) rotation system. There were three treatments: (i) long straw (5 cm) mulching with N fertilizer (CK), (ii) long straw with N fertilizer plowed into the soil (LP), and (iii) ammoniated long straw with N fertilizer plowed into the soil (ALP). Compared with the CK treatment, LP and ALP led to a similar soil water storage capacity. ALP improved summer maize biomass yield and winter wheat biomass yield at the jointing-maturity stage. ALP improved summer maize WUE at the ten-leaf collar-tasseling stage and winter wheat WUE from the tillering stage to the maturity stage. Also, the ALP treatment increased the total water use efficiency (TWUE) of winter wheat by 4.1–22.0%. Overall, ammoniated straw incorporation produced the most favorable biomass yield and WUE in the summer maize—Winter wheat rotation system in the Loess Plateau of China.
•Field experiments of cotton under drip fertigation were studied in the northwest of China.•Full irrigation 1.0 ETc obtained the highest yield and partial factor productivity (PFP).•Yield and WUE ...first increased and then decreased as the amount of fertilizer increased.•The interval of irrigation and fertilizer was determined to make yield, economic benefits and WUE reach ≥90% maximum.
Xinjiang is the main cotton-growing region in China, but the shortage of water resources and the low utilization of fertilizers have restricted its agricultural development. Field experiments were conducted during 2012–2014 to investigate the coupling effects of different amounts of water and fertilizers on seed cotton yield, water and fertilizer use efficiency as well as economic benefits in northern Xinjiang of Northwest China. The optimum combinations of water and fertilizer inputs were determined for both single-objective and multi-objective optimizations through the least squares method and multiple regression analysis. The main plots comprised of five N-P2O5-K2O fertilization levels (150-60-30, 200-80-40, 250-100-50, 300-120-60 and 350-140-70 kg ha−1), which were designated as F0.6, F0.8, F1.0, F1.2 and F1.4, respectively. Three drip irrigation levels, designated as full irrigation (1.0 ETc, ETc is the crop evapotranspiration), medium irrigation (0.8 ETc) and low irrigation (0.6 ETc), were assigned as the sub–plots. For the same fertilization level, the results revealed that leaf area index (LAI), dry matter accumulation, seed cotton yield, partial factor productivity (PFP) and the economic benefits increased with increasing irrigation water. These parameters reached their maximum values at the irrigation amount of 1.0 ETc. At the same irrigation level, the LAI, dry matter accumulation, seed cotton yield and water use efficiency (WUE) first increased and then decreased as the amount of fertilizers increased. These parameters were maximized in 2012 and 2014 when 300-120-60 kg ha−1 of fertilizers (N-P2O5-K2O) was applied. A low level of irrigation was not conducive to the functioning of fertilizers. The WUE was low, but the seed cotton yield and economic benefits were obviously higher under the full irrigation level. Therefore, based on the results of this study, full irrigation along with a fertilizer rate of 300-120-60 kg ha−1 (N-P2O5-K2O) should be considered as the best fertigation strategy for both high seed cotton yield and economic benefits. By establishing a multi-objective optimization model using binary quadratic regression analysis, it was concluded that the seed cotton yield, economic benefits and water use efficiency reached ≥90% of their maximum values simultaneously when the irrigation interval was 362.3–462.5 mm and the fertilizer (N-P2O5-K2O) interval was 212.5-85-42.5 to 367.5-147-73.5 kg ha−1. The obtained optimum combinations of water and fertilizer can provide a scientific basis for irrigation and fertilization optimization and management in northern Xinjiang of Northwest China and other regions with similar environments.
The latest Integrated Multi-satellite Retrievals for Global Precipitation Measurement (IMERG) dataset version 6, which is the successor of the multi-satellite 3B42 dataset from the Tropical Rainfall ...Measuring Mission Multi-satellite Precipitation Analysis (TMPA), is now recommended for many purposes. It is unclear how the quality of the latest IMERG data products compares to that of the delisted TMPA series data sets. This study evaluated the accuracy of TRMM 3B42 version 7 and IMERG final version 6 products at 677 stations in the 7 subregions of China over 2000–2019 at the daily, monthly and annual timescales based on gauge-observed precipitation data. The performance of TMPA and IMERG precipitation products was assessed by six statistical indices. The product with the best performance was corrected based on the linear relationship of monthly precipitation between remote sensing products and ground-observed precipitation. The correction was then used for the predicting and mapping of precipitation in July 2019. The results showed that (1) IMERG outperformed TMPA at all three timescales, and the accuracy increased with the expanding timescale. (2) IMERG exhibited better performance in all subregions than TMPA and performed best in the mid-temperate semihumid zone and worst in the mid-temperature arid zone. (3) IMERG showed higher accuracy than TMPA in all months for most subregions and mainland China but performed worse in dry (December, January and February) and wet (July, August and September) months. (4) The linear relationship between remote sensing products and ground-observed precipitation could be used to correct and predict satellite precipitation data without up-to-date gauge observations, the predicted map indicated the good spatial variation in precipitation and better accuracy than the original IMERG data. In conclusion, the IMERG dataset was more accurate and could be used for precipitation investigations at large scales in China.
•The accuracy of two satellite-retrieved precipitation data products increased with the increasing timescale in China.•IMERG performed better than TMPA at the daily, monthly and yearly timescales for most subregions.•Satellite precipitation data could be corrected and predicted with the linear relationship.
Type I collagen (PSC-I) and type V collagen (PSC-V) were directly separated by DEAE-cellulose chromatography without salt precipitation from the skin of deep-sea redfish after limited pepsin ...digestion. The yields of PSC-I and PSC-V were 79.4% and 8.4%, respectively. The denaturation temperature of PSC-V (17.8°C) was significantly higher than that of PSC-I (15.9°C), as a result of its higher total content of imino acid (17.1%) and hydroxylation degree of proline and lysine (44.7%) than those of PSC-I (14.7% and 35.8%). However, the intrinsic viscosity and viscosity transition temperature span of PSC-I (14.4dL/g and 8°C) were considerably higher than those of PSC-I (13.5dL/g and 5°C), which could be attributed to its greater extent of triple helix and more intermolecular crosslinks as shown by SDS-PAGE pattern and infrared spectra.
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•l-Histidine (His), imidazole (Imi) and l-carnosine (Car) increased solubility of myosin in low ionic strength solution.•His, Imi and Car gave myosin suspensions with small particle size ...species.•His, Imi and Car increased the absolute zeta potential of myosin suspension.•His, Imi and Car induced conformational changes of soluble myosin.•Imidazole ring was the significant constituent in His for solubilising myosin.
Myosin, a major muscle protein, can be solubilised in a low ionic strength solution containing l-histidine (His). To elucidate which chemical constituents in His are responsible for this solubilisation, we investigated the effects of 5mM His, imidazole (Imi), l-α-alanine (Ala), 1-methyl-l-histidine (M-his) and l-carnosine (Car) on particle properties of myosin suspensions and conformational characteristics of soluble myosin at low ionic strength (1mM KCl, pH 7.5). His, Imi and Car, each containing an imidazole ring, were able to induce a myosin suspension, which had small particle size species and high absolute zeta potential, thus increasing the solubility of myosin. His, Imi and Car affected the tertiary structure and decreased the α-helix content of soluble myosin. Therefore, the imidazole ring of His appeared to be the significant chemical constituent in solubilising myosin at low ionic strength solution, presumably by affecting its secondary structure.
Peer-to-peer platforms, such as Uber and Airbnb, are increasingly leveraging referral programs to attract new suppliers in addition to new customers (aka supplier-get-supplier campaigns and ...customer-get-customer campaigns). In contrast to customer referral programs where referrers and receivers mainly cooperate, supplier referral programs involve referrers and receivers sharing knowledge and competing for customers simultaneously, thereby obscuring the assessment of the receiver (new supplier) sales performance. Drawing from the literature on coopetition, this study investigates how the similarities between referrers and receivers in supplier referral programs impact the performance of receivers through coopetition. We based our investigation on a flash peer-to-peer social commerce platform in China, in which social media were leveraged to foster a dynamic and tension-filled coopetiton environment for individual suppliers. Analyzing a 2-month referral dataset from the platform through regression analyses, we find that while demographic similarity between referrers and receivers enhances the receivers’ performance, geographic similarity attenuates their performance. Moreover, the positive effect of demographic similarity on receivers’ performance decreases as the referrers’ experience increases. With an additional analysis, we have also uncovered the distinct effects of the aforementioned similarities on the performance of referrers. Collectively, these findings have important implications for both research and practice on extending referral programs from the demand side to the supply side.
The information of reference evapotranspiration (ET0) is vital for optimizing irrigation scheduling, planning water resources and assessing hydrological drought. However, accurate estimation of ET0 ...is difficult if long-term or complete climatic variables are unavailable, especially in developing countries like China. This study proposed a novel hybrid extreme gradient boosting (XGB) model with the whale optimization algorithm (WOA) to estimate daily ET0 at four stations in the arid region and four stations in the humid region of China. Particularly, its performances were evaluated under the local and three external scenarios with seven incomplete combinations of maximum and minimum temperatures (Tmax and Tmin), relative humidity (RH), wind speed (U2), relative sunshine duration (n/N) and extra-terrestrial radiation (Ra) for the period 1966–2015. The results showed that U2 was the most influencing variable for daily ET0 estimation in the arid region, followed by n/N and RH, while n/N was more important than RH and U2 in the humid region. Locally trained and tested WOA-XGB models greatly outperformed their corresponding simplified FAO-56 PM models, with the average decrease in root mean square error (RMSE) by 40.1% and 38.9% in the arid and humid regions, respectively. Compared with local WOA-XGB models, the prediction accuracy of externally trained WOA-XGB models with local or external testing data decreased by 18.1% or 69.9% in the arid region, and 16.8% or 67.9% in the humid region, respectively. However, external WOA-XGB models with synthetic testing data from the target and adjacent stations overall improved the prediction accuracy of local WOA-XGB models by 5.7% and 9.6% in the arid and humid regions, respectively. The results indicated that external WOA-XGB models with local testing data produced acceptable daily ET0 estimates. However, when synthetic data were employed during testing, external WOA-XGB models gave excellent daily ET0 estimates, which were comparable to or even better than local WOA-XGB models. This is a promising strategy that allows more accurate estimation of daily ET0 when lack of long-term historical or complete recent data.
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•A novel WOA-XGB model was proposed for estimating daily ET0 using local and external data.•U2 and n were most important for daily ET0 estimation in arid and humid regions, respectively.•WOA-XGB models greatly outperformed the corresponding simplified FAO-56 PM models.•External WOA-XGB models with local testing data produced acceptable daily ET0 estimates.•External WOA-XGB models with synthetic data gave comparable or even better ET0 estimates.
•Dual mulching of ridges with black plastic film and furrows with straw was tested•Dual mulching produced lower soil temperatures during the maize growing season•Reproductive growth period was ...extended, and photosynthetic rate was improved•Dual mulching delayed senescence and increased maize yield
Ridge-furrow farming systems with transparent plastic film have been used extensively for maize (Zea mays L.) production in semi-arid areas. However, with climate warming, problems may arise associated with premature senescence and reduced production. This study examined whether dual mulching of ridges with black plastic film and furrows with straw can delay senescence and increase summer maize yield. Summer maize cultivation experiments were conducted in 2014–2015 by ridge-furrow planting with black (BRM) or transparent (TRM) plastic film mulch over the ridge and wheat straw mulch over the furrow, flat planting with black (BM) or transparent plastic film mulch (TM), and flat planting without mulch (control treatment, CK). The objective of this experiment was to determine the effects of the different mulching treatments on soil water and temperature, evapotranspiration (ET), leaf, photosynthesis rate, yield, and water use efficiency of summer maize. The BRM and TRM treatments were superior to the BM and TM treatments in terms of soil water storage in the 0–200 cm soil profile. The BRM reduced the diurnal variation in the soil temperature and lowered the soil temperature in the root zone. The BRM treatment extended the maize reproductive growth period by 5 days compared with TM, and 2–3 days longer than for the other mulched and control treatments. The BRM also increased the leaf area and dry matter accumulation per plant while significantly increasing the leaf photosynthesis rate. Moreover, BRM increased the 100–seed dry weight and significantly improved yield and water-use efficiency. The 2–year average yield of the BRM treatment was 6.7, 13.4, 18.4, and 72.9 % greater than yield of the TRM, BM, TM, and CK treatments, respectively. The corresponding water-use efficiency improved by 11.2, 13.1, 20.3, and 72.1 %, respectively. Applying the BRM cultivation practice will effectively delay senescence and increase summer maize yield in the agricultural production area of the study region.
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