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161.
Ahmed A. Ismaiel Jutta Papenbrock 《European journal of plant pathology / European Foundation for Plant Pathology》2014,139(3):497-509
A culture of Penicillium vulpinum CM1 isolated from a soil sample cultivated with maize was examined for the production of the mycotoxins cyclopiazonic acid, griseofulvin, patulin (PAT), and roquefortine C. The fungal strain was positive for PAT- and roquefortine C–producing ability, while it showed negative producing ability for cyclopiazonic acid, and griseofulvin. Both PAT and roquefortine C toxins were tested for their inhibitory effect on the germination of maize seeds. Roquefortine C showed no phytotoxicity up to a concentration of 100 μg ml?1. However, a notable reduction in the average values of fresh weight and length of roots and shoots was observed following application of PAT and a culture filtrate of P. vulpinum to maize seedlings. The phytotoxic effect was found to be dose-dependent. To analyse the cellular effects of PAT, maize root tips were treated with PAT at different concentrations. The higher dose of 25 μg ml?1 exhibited morphological changes in the nature of cytoplasm and cytoplasmic organelles as was shown by transmission electron microscopy. Furthermore, an increase in the vacuolation with localized tonoplast dissolution was observed. At this concentration, there was evidence of a disruption of lipid metabolism. On the metabolic level, the phytotoxicity of PAT and the culture filtrate of P. vulpinum led to alterations in the total reduced glutathione (GSH) concentration in maize seedlings. The GSH concentrations examined in roots and shoots after PAT, fungal filtrate or fungal crude extract treatments were enhanced compared with control treatments. Findings further showed higher total GSH levels in shoots than in roots following treatments either with PAT or the fungal crude extract. The results are discussed in the context of known herbicide and metal effects on GSH synthesis and transport mechanisms. 相似文献
162.
Emad E. Younis Ashraf M. Ahmed Sabry A. El-Khodery Salama A. Osman Yasser F.I. El-Naker 《Research in veterinary science》2009,87(3):373-379
The aim of the present study was to carry out molecular epidemiological investigation on enterotoxigenic Escherichia coli (ETEC) K99 and Salmonella spp. in diarrheic neonatal calves. Fecal samples were obtained from 220 diarrheic calves at 9 farms related to four governorates in central and northern Egypt. E. coli and Salmonella spp. isolates were examined for E. coli K99 and Salmonella spp. using PCR. ETEC K99 was recovered from 20 (10.36 %) out of 193 isolates, whereas Salmonella spp. was recovered from nine calves (4.09%).Multivariable logistic regression was used to evaluate the risk factors associated with both infections. ETEC K99 was significantly affected by age (P < 0.01; OR: 1.812; CI 95%: 0.566–1.769), colostrum feeding practice (P < 0.01; OR: 5.525; CI 95%: 2.025–15.076), rotavirus infection (P < 0.001; OR: 2.220; CI 95%: 0.273–1.251), vaccination of pregnant dams with combined vaccine against rotavirus, coronavirus and E. coli (K99) (P < 0.001; OR: 4.753; CI 95%: 2.124–10.641), and vitamin E and selenium administration to the pregnant dam (P < 0.01; OR: 3.933; CI 95%: 0.703–1.248).Infection with Salmonella spp. was found to be significantly affected by the animal age (P < 0.05; OR: 0.376; CI 95%: 0.511–1.369), Hygiene (P < 0.05; OR: 0.628; CI 95%: 1.729–5.612), and region (P < 0. 01; OR: 0.970; CI 95%: 0.841–1.624).The results of the present study indicate the importance of PCR as rapid, effective and reliable tool for screening of ETEC and Salmonella spp. when confronted with cases of undifferentiated calf diarrhea. Moreover, identification of the risk factors associated with the spreading of bacteria causing diarrhea may be helpful for construction of suitable methods for prevention and control. 相似文献
163.
Aziz M Tab N Karim A Mekhfi H Bnouham M Ziyyat A Melhaoui A Legssyer A 《Fitoterapia》2006,77(6):425-428
The effects of the aqueous extract of Cistus ladaniferus leaves and stems were studied on the rodent isolated jejunum. The extract produced a reversible concentration dose-dependent (0.1-3 mg/ml) inhibition of the spontaneous motility of the rabbit jejunum. The inhibitory effects of the extract were not affected by pretreatment with the inhibitors of the alpha and beta adrenergic receptors yohimbine, prazosin or propranolol. The extract also inhibited K(+)-induced contractions in rabbit and rat jejunum at a similar concentration range. This result suggests that the antispasmodic action of the extract is mediated through calcium channel blockade. The results confirm the traditional use of C. ladaniferus in treating intestinal ache. 相似文献
164.
三个农林复合树种幼苗对施加磷肥的响应:生长和生节能力(英文) 总被引:1,自引:0,他引:1
Mohammad Belal Uddin Sharif Ahmed Mukul Mohammed Abu Sayed Arfin Khan Mohammed Kamal Hossain 《林业研究》2009,20(1):45-48
对苗床培养的楹树、雨豆树和水黄皮袋装幼苗(6月龄)施以80kg·hm-2的磷酸盐,通过比较不同收获间隔期幼苗生长和生节情况,研究了施加磷肥对三个农林复合树种幼苗生长和生节作用。研究表明,施加磷肥显著促进雨豆树和水黄皮幼苗生长,但并未促进楹树幼苗生长。此外,施加磷肥还会显著增加楹树、雨豆树幼苗生节数和节大小,但对水黄皮幼苗作用较小,而且高收割间隔期会降低水黄皮生节表现。 相似文献
165.
Lamiaa A. Shaala Diaa T. A. Youssef Mansour Sulaiman Fathy A. Behery Ahmed I. Foudah Khalid A. El Sayed 《Marine drugs》2012,10(11):2492-2508
A new collection of several Red Sea sponges was investigated for the discovery of potential breast cancer migration inhibitors. Extracts of the Verongid sponges Pseudoceratina arabica and Suberea mollis were selected. Bioassay-directed fractionation of both sponges, using the wound-healing assay, resulted into the isolation of several new and known brominated alkaloids. Active fractions of the sponge Pseudoceratina arabica afforded five new alkaloids, ceratinines A–E (2–6), together with the known alkaloids moloka’iamine (1), hydroxymoloka’iamine (7) and moloka’iakitamide (8). The active fraction of the sponge Suberea mollis afforded the three known alkaloids subereamolline A (9), aerothionin (10) and homoaerothionin (11). Ceratinine B (3) possesses an unprecedented 5,7-dibrominated dihydroindole moiety with an epoxy ring on the side chain of a fully substituted aromatic moiety. Ceratinines D (5) and E (6) possess a terminal formamide moiety at the ethylamine side chain. Subereamolline A (9) potently inhibited the migration and invasion of the highly metastatic human breast cancer cells MDA-MB-231 at the nanomolar doses. Subereamolline A and related brominated alkaloids are novel scaffolds appropriate for further future use for the control of metastatic breast cancer. 相似文献
166.
Samia Belkhir Ahmed KoubaaAyda Khadhri Mustapha KsontiniSamira Smiti 《Industrial Crops and Products》2012,37(1):200-206
Esparto fibers are cellulose-based fibers extracted from esparto (Stipa tenacissima) leaves. Morphological characteristics (length, width, and coarseness) of esparto fibers are analyzed in relation to growing conditions and plant biology. Seven localized sites in Kasserine in central western Tunisia are examined. The analysis of variance showed that all investigated characteristics vary significantly with site, season, and leaf level. Leaves reach minimum level in winter and maximum level in fall. Fiber differentiation is closely related to the vegetative cycle. Fibers are short and wide at the leaf base (basal level) and grow longer and thinner above the leaf. Results on the raw material (esparto leaves) were confirmed by results on esparto pulp. 相似文献
167.
The aim of this study was to investigate the load and distribution patterns of the aerobic bacterial flora associated with pond water, sediments, gills, and intestines of healthy African catfish, Clarias gariepinus, cultured in Saudi Arabia. Counts of viable bacteria ranged from 7.9 ± 4.4 103 to 4.3 ± 5.7 104 colony forming units (cfu)/mL in water; 1.3 ± 2.7 108 to 7.4 ± 4.6 109 cfu/g in sediments; 8.7 ± 1.8 106 to 6.6 ± 5.8 107 cfu/g in gill filaments; and 8.8 ± 6.2 108 to 4.3 ± 2.8 1010 cfu/g in intestines. The bacterial flora was predominantly comprised of gram-negative rods, accounting for 75% of the total isolated strains. Altogether, 11 bacterial species of 8 genera were identified: Aeromonas hydrophila, Shewanella putrefaciens, Vibrio cholerae, Staphylococcus sp., Corynebacterium urealyticum, and Vibrio vulnificus were the most common with the first three dominating (prevalence > 14%) in every population studied. 相似文献
168.
Nesar Ahmed Janet H. Brown James F. Muir 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3):207-223
The livelihoods of a large number of farmers are associated with freshwater prawn (Macrobrachium rosenbergii) farming in gher (modified rice fields with high, broad peripheral dikes) systems in southwest Bangladesh. Most farmers integrated prawn with fish and rice in their gher and followed extensive methods using low inputs. Although farmers have improved their social and economic conditions through prawn farming, constraints include high production costs, low supply of wild fry and snail meat as prawn feed, lack of technical knowledge of farmers, and negative environmental impacts. 相似文献
169.
Omkar V. Byadgi K. M. Shankar B. T. Naveen Kumar Rajreddy Patil Iqlas Ahmed 《Aquaculture International》2014,22(2):887-900
A study was conducted on the stability of monoclonal antibody (MAb) in the hepatopancreas and hemolymph of Penaeus monodon and its effect on protection against white spot syndrome virus (WSSV) upon challenge. MAb C-5 raised against WSSV was purified and coated onto a commercial shrimp feed at dosages of 5, 10 and 15 mg/kg feed. The feed was fed to P. monodon and stability of the MAb in hepatopancreas and hemolymph was determined by immunodot and Western blot. Immunodot results indicated the presence of MAb for 2 h post-feeding in hepatopancreas and hemolymph which was dose-dependent. MAb was also detected in hemolymph by Western blot up to 1 h post-feeding. Shrimp fed with MAb were challenged with WSSV by oral and injection methods. In shrimp fed with 15 mg antibody/kg feed (0.45 μg MAb/g shrimp/day) WSSV infection significantly delayed both in oral and injection challenges with a survival of 65 and 70 % (p < 0.05), respectively, during 15 days post-challenge. MAb was stable in shrimp for passive immunization against WSSV and could be a potential tool for prophylaxis against the virus. 相似文献
170.
Khadija Semhi René Boutin Nallusamy Sivakumar Walid Al Busaidi Abdallah Al Hamdi Khamis Al Dhafri Ahmed Al Busaidi 《Water, air, and soil pollution》2018,229(9):294
A radish and a grass species were grown in identical substrates either unpolluted or polluted by tungsten (W) at 1, 5, and 10 μg/g levels of watering solutions during 1 month under controlled laboratory conditions. Initially, at 4.1 μg/g, the W content in grass leaves reached 16 μg/g at the highest rate of W supply to the substrate. For radish, the content of W reached 22 and 29 μg/g in the leaves and roots, respectively. The overall W pollution increased significantly the mobility of major elements from substrate to grass leaves, especially at the 5 μg/g pollution level, whereas the W impact on radish leaves resulted in an increase of most contents, only Mn remaining unaffected. The roots from polluted radishes were enriched in Si by 21% and Al by 42% at low pollution, and in Si by 15% at high supply, whereas the uptake of the other elements remained unchanged. It looks like the W pollution at the levels chosen does not impact the transfer of the major and trace elements from roots to leaves of Raphanus sativus. Alternatively, metallic trace elements (Ba, Ni, Cr, Zn, W, Co) of the Raphanus sativus and Chloris gayana leaves outline similar content changes depending on the amount of W pollution. The total rare-earth element contents of the leaves of Raphanus sativus grown in the polluted substrates are lower than those of the leaves from unpolluted substrate. Their normalization in the leaves and roots of Raphanus sativus from the polluted substrates to those of the radish from non-polluted substrate provides flat patterns for both with a positive Eu anomaly for leaves, as for those of the grass and a negative Gd anomaly for roots. Also, addition of soluble W to the substrates induced an increase in the bacterial activity of the soil. 相似文献