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171.
The baking performance of a set of flours from 13 wheat cultivars was determined by means of two different microscale baking tests (10 g of flour each). In the micro‐rapid‐mix test the dough was mixed for a fixed time at a high speed, whereas the microbaking test used mixing to optimum dough consistency in a microfarinograph. Quality parameters such as sedimentation value, crude protein content, dough and gluten extension data, and microfarinograph data were also determined. Finally, quality‐related protein fractions (gliadins, glutenins, SDS‐soluble proteins, and glutenin macropolymer) were quantitated by extraction/HPLC methods with reversed‐phase and gel‐permeation columns. All quality parameters were correlated with the bread volumes of both baking tests. The results demonstrated that the microbaking test (adapted mixing time) was much more closely related to the quality parameters than the micro‐rapid‐mix test (fixed mixing time), which hardly showed any correlation. Among the standard quality parameters, only the crude protein content showed a medium correlation with the bread volume of the microbaking test (r = 0.71), whereas the contents of gliadins (r = 0.80), glutenins (r = 0.76), and glutenin macropolymer (r = 0.80) appeared to be suitable parameters to predict the baking performance of wheat flour. All other quality parameters were not or were only weakly correlated and unsuitable for predicting baking performance. 相似文献
172.
Miguel Urrestarazu Lizette Borges Silvia Burés Juan Eugenio Álvaro 《Journal of plant nutrition》2013,36(4):562-565
□ Plants from 60-day-old Lime Thyme (Thymus citriodorus) cuttings were potted in a medium of coconut fiber and peat moss and were treated with three different nutrient solutions: T1, T2, and T3. T1 was a standard nutrient solution; T2 was incremented with macronutrients up to an electrical conductivity (EC) of 2.8 dS m?1; and T3 was the same as T1 but incremented up to an EC of 2.8 dS m?1 with sodium chloride. The plants were then grown for 90 days in a greenhouse with natural daylight in Almería, Spain. Root growth was not affected by the treatments. The dry weight of the leaves and the total dry weight of the plants benefited from the salinity. The specific salinity of the sodium chloride negatively affected growth compared to the same salinity in the complete nutrient solution. 相似文献
173.
Anaerobic sediment potential acidification and metal release risk assessment by chemical characterization and batch resuspension experiments 总被引:1,自引:0,他引:1
Background, Aim and Scope Sediments act as a sink for toxic substances (heavy metals, organic pollutants) and, consequently, dredged materials often
contain pollutants which are above safe limits. In polluted anaerobic sediments, the presence of sulphides and redox potential
changes creates a favorable condition for sulphide oxidation to sulphate, resulting in potential toxic metal release. The
oxidation reaction is catalyzed by several microorganisms. Some clean up measures, such as dredging, can initiate the process.
The aim of the present work is to assess the acidification and metal release risk in the event of sediment dredging and also
to compare two different acid base account techniques with the resuspension results. The oxidation mechanism by means of inoculation
with an Acidithiobacillus ferrooxidans strain was also evaluated.
Methodology The sediments were chemically characterized (pH; organic oxidizable carbon; acid volatile sulphides; total sulphur; moisture;
Cr, Cu and Zn aqua regia contents). A metal sequential extraction procedure (Community Bureau of Reference, BCR technique)
was applied to calculate the Acid Producing Potential (APP) and Acid Consuming Capacity (ACC) of the sediment samples through
Fe, Ca2+ and SO4
2− measurements. The acid base account was also performed by the Sobek methodology (Acid producing potential — AP — calculated
with total sulphur and neutralization potential — NP — by titration of the remaining acid after a reaction period with the
sample). Fresh sediments were placed in agitated shake flasks and samples were taken at different times to evaluate pH, SO4
2− and Cr, Cu, Zn and Fe2+ concentration. Some of the systems were inoculated with an Acidithiobacillus ferrooxidans strain to assess the biological catalysis on sulphide oxidation.
Results Sediment chemical characterization showed high organic matter content (5.4–10.6%), total sulphur (0.36–0.86%) and equivalent
CaCO3 percentages (4.5–8%). pH was neutral-alkaline for all of the samples. AVS content was high except for sample 5. The acid
base account obtained with the two methods gave different results for the acid generating risk of the samples. A decrease
of 0.4 to 3.1 pH units was measured in the agitated shake flasks. In all of the systems, sulphate concentration increased
(2,100–2,200 mg L−1 to 2,500–3,000 mg L−1), and positively correlated with the initial total sulphur content of the samples in the inoculated flasks. Cu and Cr in
solution were not detected in most of the sampling occasions (<0.5 mg Cu L−1 and <0.5 mg Cr L−1). Zn reached high concentrations (up to 11.8 mg L−1). For every system — except sediment 1 — the lowest pH registered was similar in comparison to inoculated and control systems.
The inoculation effect was mostly evidenced in the systems by a higher sulphate release rate compared to the control systems.
Discussion The BCR method categorized all of the samples as potentially acid generating material. The Sobek method using NPR (NP/AP)
criteria classified sample 3 as a possible acid generator and samples 1, 2 and 5 with a low acid generation potential. Despite
this, all the samples acidified the media in the kinetic tests in at least one of the conditions employed in this work. It
would seem that NPR and NNP (NP-AP) risk classification criteria should not be directly used with anaerobic sediments. Appropriate
classification levels for sediments should be developed considering the different sulphide reactivity between rock and sediments.
Sediment oxidation can cause acidification, which is partially explained by sulphide oxidation. In the samples studied, we
found a positive correlation between sulphate increase in solution after oxidation and total sulphur content in the inoculated
systems. Significant amounts of Zn could be released to solution while Cr and Cu remained insoluble despite the pH decrease
observed. The low Cu and Cr mobility could be explained by the very low solubility of their hydroxides and high affinity for
organic matter and iron oxides/hydroxides that might form during sediment oxidation. Dredged sediment management and disposal
should be carefully planned.
Conclusions All of the sediment samples lowered the pH media in the laboratory batch resuspension experiments. However, both risk classification
criteria (NNP, NPR) from Sobek acid base account were not able to predict the samples’ behavior as accurately as the BCR derived
base account. The inoculation effect was mostly associated with a higher sulphate release and not to a lower pH due to acid
base equilibrium.
Recommendations and Perspectives Appropriate risk classification levels for sediments should be developed considering the different sulphide reactivity between
rock and sediments.
ESS-Submission Editor: Dr. Sabine Ulrike Gerbersdorf (sug@st-andrews.ac.uk) 相似文献
174.
The potato tuberworm Phthorimaea operculella Zeller, is one of the most important potato pests worldwide including China. Several reports indicate that P. operculella could be controlled biologically by the use of beneficial fungus such as Beauveria bassiana(Bals.-Criv) Vuill. However, limited information is available under growing conditions in China. Thus, this study evaluated the sub-lethal effects of B. bassiana on the offspring of P. operculella by the age-stage, two-sex life table. First instar larva of P. operculella were treated with 1×107 conidia m L–1 of the fungus, and several biological parameters were evaluated. The fecundity, duration of the egg stage, all larval stages, pre-adult stage, and total pre-oviposition period, were significantly shorter than the control treatment. Offspring of treated parents, presented a net reproductive rate and mean generation time of 17.43 per day and 24.98 days, respectively, compared to 65.79 per day and 26.51 days for the untreated ones. This study provides basic information to help understanding the potential long-term effects of entomopathogenic fungi on P. operculella. 相似文献
175.
Wagner de Souza Tavares Ivan Cruz Fernando Petacci Sebastio Loureno de Assis Júnior Silvia de Sousa Freitas Jos Cola Zanuncio Jos Eduardo Serro 《Industrial Crops and Products》2009,30(3):384-388
Extracts of 12 Asteraceae were tested on Spodoptera frugiperda (Lepidoptera: Noctuidae) and on their parasitoids Telenomus remus (Hymenoptera: Scelionidae) and Trichogramma pretiosum (Hymenoptera: Trichogrammatidae). The plants Lychnophora ericoides and Trichogonia villosa were toxic for 97.7 ± 0.15% of one-day-old eggs of S. frugiperda and Lepidaploa lilacina for 72.0 ± 2.50% for two-day-old eggs of this insect. Extracts of Vernonia holosenicea, Lychnophora ramosissima and Chromolaena chaseae had higher impact on S. frugiperda, while those of Eremanthus elaeagnus and L. ericoides were more selective to T. pretiosum and T. remus. Asteraceae extracts present potential for integrated pest management programs of S. frugiperda. 相似文献
176.
Víctor López Anna K. Jäger Silvia Akerreta Rita Yolanda Cavero Maria Isabel Calvo 《Plant foods for human nutrition (Dordrecht, Netherlands)》2010,65(2):179-185
Phlomis lychnitis L. (Lamiaceae) is consumed as a traditional herbal tea in Spain. The antioxidant-protective effects as well as its phytoconstituents have never been established. The ability of the methanolic extract to protect cells from oxidative stress was evaluated in rat pheochromocytoma cells (PC12) using hydrogen peroxide as toxic agent. The viability of PC12 cells pre-treated with the methanolic extract of Phlomis lychnitis, determined by the MTT and LDH assays, was significantly improved at the highest dose (p?<?0.01). The antioxidant activity was confirmed evaluating the capacity of the plant to scavenge ABTS, DPPH, O2 · ? radicals and to inhibit XO. Bioassay guided fractionation led to antioxidant compounds. Qualitative HPLC/DAD/ESI/MS analysis reported phenylpropanoids, verbascoside being the major antioxidant constituent. 相似文献
177.
Mayra L. González-Félix Silvia Gómez-Jiménez Martin Perez-Velazquez D. Allen Davis & José G. Velazco-Rameños 《Aquaculture Research》2007,38(8):798-808
A 4‐week study was conducted to evaluate the effects of different dietary protein levels (25%, 30%, 35% and 40%) on the growth and survival of juvenile Litopenaeus vannamei raised in a low salinity (4.6 g L−1), zero‐water exchange culture system, as well as on the nitrogen budget and ammonia efflux rate. No significant differences were observed among the dietary treatments for final weight, weight gain or survival of shrimp, although the best performance was observed in the 25% protein treatment group. Both weight and survival decreased as the dietary protein increased. Significant differences (P<0.05) were observed in the ammonia concentration among dietary treatments during the first 2 weeks of the experiment. The highest concentration was measured in the 40% dietary protein treatment (5.88 mg NH4‐N L−1). The nitrogen budget showed that the nitrogen loss increased as the dietary protein increased under the experimental conditions; the largest amount of nitrogen recovered as shrimp biomass (42.9%) was in the 25% protein treatment group, and the largest amount of unaccounted nitrogen (39.5%) was in the 40% protein treatment. Under these conditions, utilization of low‐protein diets resulted in better performance, presumably because they provided more carbon for heterotrophic bacteria and reduced the nitrogen loading of the system. 相似文献
178.
Summary Four introductions ofSolanum berthaultii wild species and sevenS. tuberosumxS. berthaultii hybrids were evaluated by antibiosis and antixenosis laboratory tests with potato tuber moth. Some morphological and chemical
traits related to the trichomes were analysed. Two clones of the wild speciesS. sparsipilum and five ofS. pinnatisectum, characterised by high tuber resistance, were tested for leaf resistance, both by antibiosis and antixenosis assays. The
genotypes with high density of trichomes A and with high exudate PPO activity, showed a moderate negative effect on pupal
weight and fecundity in the antibiosis tests. Trichomes B exudate showed a strong repulsive effect on oviposition of adult
in the antixenosis tests. TheS. pinnatisectum clones revealed a good leaf resistance level, whereas theS. sparsipilum clones showed lower levels of antibiosis and antixenosis. 相似文献
179.
Vanmierlo T Rutten K van Vark-van der Zee LC Friedrichs S Bloks VW Blokland A Ramaekers FC Sijbrands E Steinbusch H Prickaerts J Kuipers F Lütjohann D Mulder M 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(2):149-156
Plant sterols such as sitosterol and campesterol are frequently applied as functional food in the prevention of atherosclerosis. Recently, it became clear that plasma derived plant sterols accumulate in murine brains. We questioned whether plant sterols in the brain are associated with alterations in brain cholesterol homeostasis and subsequently with brain functions. ATP binding cassette (Abc)g5-/- mice, a phytosterolemia model, were compared to Abcg5+/+ mice for serum and brain plant sterol accumulation and behavioral and cognitive performance. Serum and brain plant sterol concentrations were respectively 35-70-fold and 5-12-fold increased in Abcg5-/- mice (P<0.001). Plant sterol accumulation resulted in decreased levels of desmosterol (P<0.01) and 24(S)-hydroxycholesterol (P<0.01) in the hippocampus, the brain region important for learning and memory functions, and increased lanosterol levels (P<0.01) in the cortex. However, Abcg5-/- and Abcg5+/+ displayed no differences in memory functions or in anxiety and mood related behavior. The swimming speed of the Abcg5-/- mice was slightly higher compared to Abcg5+/+ mice (P<0.001). In conclusion, plant sterols in the brains of Abcg5-/- mice did have consequences for brain cholesterol metabolism, but did not lead to an overt phenotype of memory or anxiety related behavior. Thus, our data provide no contra-indication for nutritional intake of plant sterol enriched nutrition. 相似文献
180.
Kocaturk M Martinez S Eralp O Tvarijonaviciute A Ceron J Yilmaz Z 《Research in veterinary science》2012,92(1):24-29
Tei index (myocardial performance) and cardiac biomarkers were evaluated in dogs with parvoviral enteritis (PVE). Tei index was calculated as isovolumic contraction time plus isovolumic relaxation time divided by ejection time. Myocardial and skeletal muscle damages were assessed by serum levels of cardiac troponin I (cTnI), creatine (phospho) kinase, lactate dehydrogenase and aspartate aminotransferase. Serum magnesium level was also determined. According to treatment response, dogs were divided into the survivor (n=20) and non-survivor groups (n=23). Seven healthy dogs served as controls. The mean value of the Tei index was higher in non-survivors, compared with survivors (p<0.02) and healthy controls (p<0.01). Serum level of cTnI in non-survivors was higher than that of survivors and controls (p<0.05). Tei index showed the highest sensitivity and specificity to predict mortality. The findings of an elevated Tei index and an increase in serum cTnI are factors associated with a poor prognosis in cases of canine parvovirosis. 相似文献