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101.
The present work describes the development by response surface methodology of a method for manganese and iron determination by flame atomic absorption spectrometry (FAAS) in cereal flours, which is based on microwave assisted extraction. The optimization process was performed using two level fractional factorial designs (24-1) and Doehlert design matrix. Four variables such as irradiation power, time, temperature and concentration of nitric acid were regarded as factors in the optimization. Results of two level fractional factorial designs with 10 runs for manganese and iron extraction, based on the Pareto chart, demonstrated that the factors irradiation power, time and temperature are statistically significant, and concentration of nitric acid is not significant. Then, a Doehlert design was carried out in order to determine the optimum conditions for the procedure through response surface study. The working conditions were established as a compromise between optimum values found for each analyte. These values were 87.0°C, 573.0 W and 40.0 min, for temperature, irradiation power and time, respectively. The accuracy of the optimized procedure was evaluated by analysis of certified reference material. The procedure proposed was applied for the determination of iron and manganese in cereal flours.  相似文献   
102.
An 8-week feeding trial was conducted to compare the effects of supplementing (0.7 mg kg?1) different dietary selenium (Se) sources including organic [selenomethionine (SeMet)], inorganic [sodium selenite (Na2SeO3)], and nanoparticulate Se (nano-Se) on physiological responses of common carp, Cyprinus carpio juveniles (9.7?±?0.1 g). Basal diet without Se supplementation used as control. Fish fed nano-Se supplemented diet had the highest weight gain (97.2?±?10.8%) and feed efficiency ratio (42.4?±?0.8%). Intestinal villi height was significantly taller in fish fed nano-Se diet than in the control group in both foregut and midgut sections. Serum glutathione peroxidase and superoxide dismutase activities were significantly higher in nano-Se and SeMet groups than in control and sodium selenite groups. Fish fed Se-supplemented diets had greater red blood cell counts and hematocrit and hemoglobin values than the control group (P?<?0.05). Nano-Se and SeMet groups showed a significant increase in white blood cell counts, neutrophil percentage, and serum lysozyme activity than the other groups. Fish fed nano-Se diet had the highest serum hemolytic activity, total immunoglobulin, and total protein and albumin contents, as well as the lowest serum total cholesterol and low density lipoprotein levels (P?<?0.05). Overall, significant improvements in growth performance, feed utilization, intestinal morphology, and hemato-immunological and serum biochemical parameters of common carp juveniles suggest nano-Se as an efficient source for providing dietary Se in this species.  相似文献   
103.
The effect of the dietary incorporation of drumstick, Moringa oleifera, leaf meal (MOL; 0, 5, 10 and 15%) on the growth, feed utilization, some skin mucus and systemic immune parameters and intestinal immune-related gene expression in gilthead seabream (Sparus aurata) specimens. The experiment lasted 4 weeks. The results revealed that MOL can be incorporated in S. aurata diet up to 10% with no significant negative effect on growth and feed utilization. However, there was a significant decrease with MOL at a level of 15% after 2 weeks of feeding. The systemic immune status of fish fed with the different levels of MOL showed an improvement in head kidney leucocyte phagocytosis, respiratory burst and peroxidase activities. Also, serum humoral components, including protease, ACH50 and lysozyme activities and IgM level, increased with MOL inclusion especially at the 5% level. MOL at 5% improved skin-mucosal immunity such as protease, antiprotease, peroxidase and lysozyme activities. Moreover, the feeding of MOL revealed an upregulation of the intestinal mucosal immunity genes (lyso and c3), tight junction proteins (occludin and zo-1) and anti-inflammatory cytokines (tgf-β) with a downregulation of pro-inflammatory cytokine (tnf-α). Therefore, it is recommended to incorporate MOL in S. aurata diets at a level of 5% for the best immune status or 10% for the high growth performance and acceptable immune surveillance.
Graphical abstract ?
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104.
An outdoor pot experiment was conducted in 2014/2015 growing season at Giza Agricultural Research Station to evaluate powdery mildew (PM) severity on 18 flax lines. The tested lines were divided into two distinct groups. The first group included 12 highly resistant lines (HRLs). Disease severity on these lines ranged from 1 to 10%. The second group included 6 highly susceptible lines (HSLs) where disease severity ranged from 90–100%. Levels and activities of phenols, alkaloids, proteins, proline, polyphenol oxidase and peroxidase significantly increased in the infected leaves of the HRLs, compared with the HSLs. Of these components, phenols and peroxidase showed the highest increases in the HRLs (102.34 and 199.33%, respectively). These results indicate that the tested biochemical components have roles to play in flax defense against PM through a variety of mechanisms. The results also suggest that phenols or peroxidase in infected leaves could be used in breeding programs to select resistant lines at early stage of PM development.  相似文献   
105.
Characterization of fecundity genes offers the opportunity to improve production efficiency, and the consequent increase in litter size in livestock industry, through utilizing them in breeding programs. The main objective of this study was to detect the BMPR‐IB, BMP15 and GDF9 gene mutations and to investigate whether these mutations are associated with litter size in Egyptian sheep breeds. To achieve this goal, 73 adult ewes representing Barki (n = 33) and Rahmani (n = 40) breeds were used. Polymerase chain reaction–restriction fragment length polymorphism (PCR‐RFLP) screening approach was used to detect the presence of FecB, FecXG and FecXI mutations in the two selected breeds. Results of this study showed that the three different candidate gene mutations, namely FecB, FecXG and FecXI are not present among these selected populations of the Egyptian breeds. Further studies regarding other mutations and/or other genes, which may influence ovulation rate, should be carried out to determine the type and mode of inheritance of such genes in Egyptian sheep breeds.  相似文献   
106.
Feed has been reported as a vehicle for transmission of Salmonella enterica in cattle and several lines of evidence suggest that feed can be a vehicle for transmitting Escherichia coli O157:H7 as well. To show whether microbial contamination of feeds could contribute to the populations of S. enterica and E. coli O157:H7 on a farm, we compared isolates from feed samples to bovine fecal isolates from the same farm using pulsed-field gel electrophoresis (PFGE). Four of 2365 component feed samples (0.2%) and 1 of 226 feed mill samples (0.4%) were positive for E. coli O157:H7. Twenty of 2405 (0.8%) component feed samples and none of 226 feed mill samples were positive for Salmonella. PFGE profiles from E. coli O157:H7 isolated from a component feed sample closely resembled that from a fecal isolate collected later from the same farm, and a similar observation was made of a Salmonella Tyhpimurium isolate from component feed on another farm. There were indistinguishable PFGE profiles from component feed Salmonella Tyhpimurium DT104 isolates and fecal isolates from the same farm. These results provide evidence for a role of cattle feed in transmission of E. coli O157:H7; S. enterica; cattle-bacteria.  相似文献   
107.
ABSTRACT Resistance of mature berries of grapevine cultivars and selections to postharvest infection by Botrytis cinerea was assessed. Little or no resistance existed in most popular table grape Vitis vinifera cultivars, except in moderately resistant 'Emperor' and 'Autumn Black'. Highly resistant grapes were V. rotundifolia, V. labrusca, or other complex hybrids. Morphological, anatomical, and chemical characteristics of 42 genetically diverse cultivars and selections with various levels of resistance to B. cinerea were examined to determine which features were associated with resistance. We quantified the (i) density of berries within a cluster; (ii) number of pores and lenticels on the berry surface; (iii) thickness and number of cell layers in the epidermis and external hypodermis; (iv) amount of cuticle and wax; (v) berry skin protein content; (vi) total phenolic content of the skin before and after B. cinerea inoculation; and (vii) catechin and trans- and cis-resveratrol contents of the skin before and after inoculation. The number of pores was negatively correlated with resistance. Highly resistant cultivars had few or no pores in the berry surface. The number and thickness of epidermal and hypodermal cell layers and cuticle and wax contents were positively correlated with resistance. Other characteristics evaluated were not associated with resistance. trans-Resveratrol and cis-resveratrol were induced by B. cinerea inoculation only in sensitive and moderately resistant cultivars and selections.  相似文献   
108.
Photolysis of isoxaben [N-[3-(1-ethyl-1-methylpropyl)isoxazol-5-yl]-2,6-dimethoxybenzamide] in dilute aqueous solutions, adsorbed on silica gel plates, has been investigated under natural and simulated solar light conditions. Eight photoproducts were isolated and identified by spectroscopic methods. Photo-decomposition with sunlight led to the formation of three isomers, dimethoxy-benzonitrile and dimethoxybenzamide as major photoproducts. The rearrangement has been shown to proceed in two photochemical steps by way of an azirine and a non-identified photoproduct as stable intermediates. The azirine rearranges almost quantitatively to an oxazole and rearranges back to the starting isoxaben.  相似文献   
109.
Control of the spider miteTetranychus cinnabarinus Boisduval is problematic, and there is a pressing need for efficient, non-hazardous and inexpensive strategies for limiting the damage it causes. The gene for the anti-bacterial peptide sarcotoxin IA of the flesh flySarcophaga peregrina was cloned into the nonpathogenic potyvirus-based vector system ZYMV-AGII (Zucchini yellow mosaic virus-AGII). Expression of this peptidevia the AGII vector was detected in infected squash leaves and was not deleterious to the host plant. Leaf discs of squash infected with the recombinant virus AGII-sarcotoxin IA were tested for spider mite control under laboratory conditions. Spider mite egg production on plants expressing the sarcotoxin IA gene was decreased by a factor of two or three compared with that on AGII-infected plants or healthy leaf discs, respectively. In contrast to its effect on oviposition, sarcotoxin IA expressing squash did not significantly affect the mortality and the ability to repel spider mites. Crude extract from squash leaves infected with AGII-sarcotoxin IA was also found to cause a significant decrease of mite fecundity compared with extracts from AGII-treated or healthy plants and also caused a rise in mite mortality. Our results demonstrate that sarcotoxin IA affects mite fecundity and, to a lesser degree, mortality, and shows potential for controlling spider mites in the field.  相似文献   
110.
F. Mansour 《Phytoparasitica》1988,16(3):239-245
Dosage mortality data for 12 pesticides were determined with females of an insecticide-susceptible strain of the carmine spider mite,Tetranychus cinnabarinus (Boisd.), by the slide dip method; for four of the pesticides which are specific acaricides, also the Munger cell method was used. The LC50s ranged from 0.00078% to 0.041%, with the synthetic pyrethroids being more toxic than the specific acaricides. There were no differences in results between the two assay methods. Four synthetic pyrethroids that were very active againstT. cinnabarinus in laboratory tests were examined in an unsprayed apple orchard for their effect on the population density of spider mites. An upsurge of tetranychid mites was noted 4 weeks after a single application  相似文献   
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