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131.
The development of ecological circular agriculture has been highly encouraged by the Chinese government to recycle agricultural wastes, reduce mineral fertilizer input, and protect the environment. Biogas slurry, a byproduct of biogas engineering developed in rural areas of China, could be used as N fertilizer for crop growth. The field experiments were conducted in 2014 and 2015 to study the plant growth responses and environmental impacts of applying biogas slurry to two-season Zizania aquatica Turcz. growth. The potential factors that restrict the rational use of biogas slurry were also clarified. Mineral N fertilizer can be completely or partly substituted by N fertilizer from biogas slurry to satisfy Z. aquatica plant growth. It was not at the cost of sacrificing yield, dry matter accumulation, N accumulation and physiological N use efficiency in the above-ground parts. However, the growth inhibition occurs when the N quantity in biogas slurry was 2 or 2.7 times higher than that of mineral N fertilizer. Vitamin C in non-shell swollen culms (as edible part) of Z. aquatica significantly increased after biogas slurry application. Biogas slurry application substantially increased the N concentrations, i.e., total N, NH4 +–N, and NO3 ?–N in floodwater and delayed the time to reach national discharge standards. However, biogas slurry application did not affect the N concentrations in percolating water compared with the treatment with mineral N fertilizer only. Applying biogass slurry did not generate potential pollution risks by trace elements (Cu, Zn, Pb, Cr, Cd, As, and Hg) in the non-shell swollen culm and soil, and did not increase the nitrate content in non-shell swollen culm. We found the NH4 +–N concentration in biogas slurry can account for 77–93% of total N and reflects the N level in biogas slurry to a great degree. Semi-quantitative color-based colorimetric methods possessing simple and fast characteristics should be developed to determine the NH4 +–N concentration with the purpose of promoting reasonable use of biogas slurry in area of crop cultivation. Otherwise, excessive use of biogas slurry can adversely affect crops and increase environmental risks.  相似文献   
132.
We recently demonstrated that daily whole egg consumption during moderate carbohydrate restriction leads to greater increases in plasma HDL-cholesterol (HDL-C) and improvements in HDL profiles in metabolic syndrome (MetS) when compared to intake of a yolk-free egg substitute. We further investigated the effects of this intervention on HDL composition and function, hypothesizing that the phospholipid species present in egg yolk modulate HDL lipid composition to increase the cholesterol-accepting capacity of subject serum. Men and women classified with MetS were randomly assigned to consume either three whole eggs (EGG, n = 20) per day or the equivalent amount of egg substitute (SUB, n = 17) throughout a 12-week moderate carbohydrate-restricted (25–30 % of energy) diet. Relative to other HDL lipids, HDL-cholesteryl ester content increased in all subjects, with greater increases in the SUB group. Further, HDL-triacylglycerol content was reduced in EGG group subjects with normal baseline plasma HDL-C, resulting in increases in HDL-CE/TAG ratios in both groups. Phospholipid analysis by mass spectrometry revealed that HDL became enriched in phosphatidylethanolamine in the EGG group, and that EGG group HDL better reflected sphingomyelin species present in the whole egg product at week 12 compared to baseline. Further, macrophage cholesterol efflux to EGG subject serum increased from baseline to week 12, whereas no changes were observed in the SUB group. Together, these findings suggest that daily egg consumption promotes favorable shifts in HDL lipid composition and function beyond increasing plasma HDL-C in MetS.  相似文献   
133.
A simple, fast and accurate Fourier transform mid-infrared spectroscopy method was developed for simultaneously determining sugar and organic acid contents in apricot fruit slurries using the attenuated total reflectance. The potential of this method coupled with chemometric techniques based on partial least squares was assessed by comparison with currently used enzymatic determination of sucrose, glucose, fructose, malic acid and citric acid. Fruits of eight contrasted cultivars harvested at different ripening stages were used in this study and randomly divided in a calibration set (505 apricots) and in a validation set (252 apricots). The most suitable region was found in the range between 1500 and 900 cm−1. Good prediction performances were obtained (R2 ? 0.74 and RMSEP ? 18%). Results concerning the prediction of other quality traits such as firmness, skin colour, ethylene production, soluble solids content and titratable acidity were discussed.  相似文献   
134.
A non-destructive optical method based on near-infrared spectroscopy has been used for the evaluation of apricot fruit quality. Diffuse reflectance measurements (800–2500 nm), physical, physiological and biochemical measurements were performed individually on 877 apricot fruits from eight contrasted cultivars harvested at different ripening stages. Relationships between spectral wavelengths and quality attributes were evaluated by application of chemometric techniques based on partial least squares (PLS) on fruit set divided randomly into two groups: 598 fruits for calibration and 279 for validation. Good prediction performance was obtained for soluble solids and titratable acidity with correlation coefficients of 0.92 and 0.89 respectively and root mean square errors of prediction of 0.98% Brix and 3.62 meq 100 g−1 FW respectively. For the other quality traits such as firmness, ethylene, individual sugars and organic acids, the prediction models were not satisfactorily accurate due to the high error of calibration and prediction.  相似文献   
135.
Small dams for hydropower have caused widespread alteration of Central American rivers, yet much of recent development has gone undocumented by scientists and conservationists. We examined the ecological effects of a small hydropower plant (Doña Julia Hydroelectric Center) on two low‐order streams (the Puerto Viejo River and Quebradon stream) draining a mountainous area of Costa Rica. Operation of the Doña Julia plant has dewatered these streams, reducing discharge to ~10% of average annual flow. This study compared fish assemblage composition and aquatic habitat upstream and downstream of diversion dams on two streams and along a ~4 km dewatered reach of the Puerto Viejo River in an attempt to evaluate current instream flow recommendations for regulated Costa Rican streams. Our results indicated that fish assemblages directly upstream and downstream of the dam on the third order Puerto Viejo River were dissimilar, suggesting that the small dam (< 15 m high) hindered movement of fishes. Along the ~4 km dewatered reach of the Puerto Viejo River, species count increased with downstream distance from the dam. However, estimated species richness and overall fish abundance were not significantly correlated with downstream distance from the dam. Our results suggested that effects of stream dewatering may be most pronounced for a subset of species with more complex reproductive requirements, classified as equilibrium‐type species based on their life‐history. In the absence of changes to current operations, we expect that fish assemblages in the Puerto Viejo River will be increasingly dominated by opportunistic‐type, colonizing fish species. Operations of many other small hydropower plants in Costa Rica and other parts of Central America mirror those of Doña Julia; the methods and results of this study may be applicable to some of those projects. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
136.
The hepatopancreas of crustaceans species has been recognized as an essential target organ to assess trace elements' effects. Due to its dynamic and capability of detoxifying trace metal, this organ often indicates distinct pathological disturbances. In the present work, we intend to evaluate the bioaccumulation of trace metal in three Orchestia species (Orchestia montagui, Orchestia gammarellus, and Orchestia mediterranea) living in symmetry in the banks of Bizerte lagoon (37°13′8″N 09°55′1″E) after their exposure during 14 days to a mixture of copper and zinc, and to highlight the effect of these metals on their hepatopancreas ultrastructure using transmission electron microscopy. At the end of the experiment, results showed that the mortality and the body mass varied according to the used nominal concentrations. Significant alterations were noted in all the treatment groups. The degree of these alterations depends on the used concentration, and they are represented especially by the cells remoteness and the border lyses, the reduction of the nuclear volume, the increase in the cytoplasm density with the presence of trace metal in the nucleus as well as in the vacuole, the disorganization and the destruction of microvilli, the condensation of the majority of cellular organelles and mitochondria swelling. Through this study, Orchestia genus could be an attractive candidate for the biochemical study of trace metal toxicity in Tunisian wetlands.  相似文献   
137.
Alarm pheromones in social insects are an essential part of a complex of pheromone interactions that contribute to the maintenance of colony integrity and sociality. The alarm pheromones of ants were among the first examples of animal pheromones identified, primarily because of the large amount of chemical produced and the distinctive responses of ants to the pheromone. However, the alarm pheromone of the fire ant, Solenopsis invicta, eluded identification for over four decades. We identified 2-ethyl-3,6-dimethylpyrazine as an alarm pheromone component of S. invicta. Worker fire ants detect the pyrazine alarm pheromone at 30 pg/ml, which is comparable to alarm pheromone sensitivities reported for other ant species. The source of this alarm pheromone are the mandibular glands, which, in fire ants, are not well developed and contain only about 300 pg of the compound, much less than the microgram quantities of alarm pheromones reported for several other ant species. Female and male sexuals and workers produce the pyrazine, which suggests that it may be involved in fire ant mating flight initiation, as well as the typical worker alarm response. This is the first report of 2-ethyl-3,6-dimethylpyrazine from a Solenopsis species and the first example of this alkaloid functioning as an alarm pheromone.  相似文献   
138.
The recent EU Commission proposal for promoting the supply of power from renewable energy sources was originally based on a pan-European, harmonised tradable green certificate (TGC) scheme. We suggest, on the basis of a multi-disciplinary analysis, that a pan-EU TGC system is not the way forward for Europe. It is vital that the Commission (and the majority of Member States) avoids implementation of such policy designs put forward by a coalition of vested interests. They should instead look at, and act upon, the available evidence from those countries that have experimented with TGCs (e.g. Flanders, UK and Sweden) and design policies that stand a better chance of meeting the criteria of effectiveness, efficiency and equity. In particular, the policies must enable EU to meet the immense innovation/industrialisation challenge by inducing the development of a capital goods industry that can, eventually, diffuse a broad range of technologies that use renewable energy sources. Only then we can acquire an ability to implement an industrial revolution in the energy system in a way that broadly meets the criteria of effectiveness and dynamic efficiency.  相似文献   
139.
This study examined the longitudinal effects of 2 first-grade universal preventive interventions on academic outcomes (e.g., achievement, special education service use, graduation, postsecondary education) through age 19 in a sample of 678 urban, primarily African American children. The classroom-centered intervention combined the Good Behavior Game (H. H. Barrish, Saunders, & Wolfe, 1969) with an enhanced academic curriculum, whereas a second intervention, the Family–School Partnership, focused on promoting parental involvement in educational activities and bolstering parents’ behavior management strategies. Both programs aimed to address the proximal targets of aggressive behavior and poor academic achievement. Although the effects varied by gender, the classroom-centered intervention was associated with higher scores on standardized achievement tests, greater odds of high school graduation and college attendance, and reduced odds of special education service use. The intervention effects of the Family–School Partnership were in the expected direction; however, only 1 effect reached statistical significance. The findings of this randomized controlled trial illustrate the long-term educational impact of preventive interventions in early elementary school. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
140.
Cast-mono crystalline silicon wafers contain crystallographic defects, which can severely impact the electrical performance of solar cells. This paper demonstrates that applying hydrogenation processes at moderate temperatures to finished screen print cells can passivate dislocation clusters within the cast-mono crystalline silicon wafers far better than the hydrogenation received during standard commercial firing conditions. Efficiency enhancements of up to 2% absolute are demonstrated on wafers with high dislocation densities. The impact of illumination to manipulate the charge state of hydrogen during annealing is investigated and found to not be significant on the wafers used in this study. This finding is contrary to a previous study on similar wafers that concluded increased H or H0 from laser illumination was responsible for the further passivation of positively charged dangling bonds within the dislocation clusters.  相似文献   
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