Effect of s-metolachlor application timing on cabbage tolerance     

Peter H. Sikkema  Nader Soltani  William Deen  Darren E. Robinson 《Crop Protection》2007,26(12):1755-1758

There is limited information on the effect of s-metolachlor application timing on cabbage tolerance in Ontario. A total of five field trials (1999–2004) were established near Ridgetown Ontario, Canada to evaluate tolerance of cabbage to s-metolachlor applied pre-transplant incorporated, pre-transplant and post-transplant at 800, 1600 and 2400 g a.i./ha. s-Metolachlor applied pre-transplant incorporated, pre-transplant and post-transplant at 800, 1600 and 2400 g a.i./ha did not have any effect on visual injury, marketable head production, marketable head weight and yield of cabbage. There was also no difference among s-metolachlor application timings (pre-transplant incorporated, pre-transplant and post-transplant) in respect to cabbage tolerance. Based on these results s-metolachlor applied pre-transplant incorporated, pre-transplant and post-transplant at 800, 1600 and 2400 g a.i./ha has an acceptable level of crop safety in cabbage.  相似文献   

The population structure of Salmonella enterica Enteritidis in Iran analyzed by multiple-locus variable-number tandem repeat analysis     

Rainak Ghaderi  Keyvan Tadayon  Sargis Avagyan  Pejvak Khaki  Soheila Moradi Bidhendi  Ken James Forbes  Nader Mosavari  Mohammad Reza Toroghi  Farhad Moosakhani  Reza Banihashemi  Mohamad Sekhavati  Nasim Karimnasab 《Tropical animal health and production》2013,45(4):889-894

Salmonella enterica Enteritidis is the most frequent etiological agent of salmonellosis in humans and poultry. To understand the genetic diversity of S. Enteritidis in Iran, we examined 69 chicken isolates from 18 broiler farms and six non-epidemic human isolates from six geographically distant provinces by multi-locus variable-number tandem repeat analysis (MLVA). Among SE2, SE3, SE5, SE7, SE8, SENTR4, and SENTR7, only SE5 with four and SENTR7 with two alleles, respectively, proved variable giving estimates of locus genetic diversity of 0.58 and 0. In all, six closely related MLVA profiles were identified among which three were commonly represented by human and chicken isolates. This population homogeneity contrasts with the high diversity at these loci reported elsewhere and is likely a consequence of a single clone of S. Enteritidis distributed across Iran.  相似文献   

Evaluation of Anti-Nociceptive and Anti-Inflammatory Activities of a Heterofucan from Dictyota menstrualis     

Ivan Rui Lopes Albuquerque  Sara Lima Cordeiro  Dayanne Lopes Gomes  Juliana Luporini Dreyfuss  Luciana Guimar?es Alves Filgueira  Edda Lisboa Leite  Helena Bonciani Nader  Hugo Alexandre Oliveira Rocha 《Marine drugs》2013,11(8):2722-2740

Fucan is a term that defines a family of homo- and hetero-polysaccharides containing sulfated l-fucose in its structure. In this work, a heterofucan (F2.0v) from the seaweed, Dictyota menstrualis, was evaluated as an antinociceptive and anti-inflammatory agent. F2.0v (20.0 mg/kg) inhibits 100% of leukocyte migration into the peritoneal cavity after chemical stimulation. However, F2.0v does not alter the expression of interleukin-1 beta (IL-1β) and interleukin-6 (IL-6), as well as tumor necrosis factor alpha (TNF-α). F2.0v (20.0 mg/kg) has peripheral antinociceptive activity with potency similar to dipyrone. On the other hand, it had no effect on pain response on the hot plate test. Confocal microscopy analysis and flow cytometry showed that F2.0v binds to the surface of leucocytes, which leads us to suggest that the mechanism of action of anti-inflammatory and antinociceptive F2.0v is related to its ability to inhibit the migration of leukocytes to the site of tissue injury. In summary, the data show that F2.0v compound has great potential as an antinociceptive and anti-inflammatory, and future studies will be performed to further characterize the mechanism of action of F2.0v.  相似文献   

Effects of exogenous salicylic acid and nitric oxide on lipid peroxidation and antioxidant enzyme activities in leaves of Brassica napus L. under nickel stress     

Nader Kazemi  Ramazan Ali Khavari-NejadHamid Fahimi  Sara SaadatmandTaher Nejad-Sattari 《Scientia Horticulturae》2010

The effects of nickel in combination with salicylic acid (SA) and sodium nitroprusside (SNP), a donor of nitric oxide (NO) on 21-day-old canola plants were evaluated. Exposure to 0.5 mM NiCl₂·6H₂O for 10 days resulted in toxicity symptoms such as chlorosis and necrosis at leaves. Addition of 0.2 mM SA or 0.2 mM SNP slightly reduced the toxic effects of nickel. After application of both SA and NO, these symptoms considerably decreased. Treatment with Ni resulted in a decrease in dry weight of roots and shoots and chlorophyll content of leaves. In Ni-treated plants, level of lipoxygenase activity and malondialdehyde (MDA), H₂O₂ and proline contents significantly increased, while the activities of the antioxidant enzymes such as catalase, guaiacol peroxidase and ascorbate peroxidase decreased in leaves. The results indicated that Ni caused an oxidative stress in canola plants. The Ni-stressed plants exposed to SA or NO, especially to SA + NO, exhibited an improved growth as compared to Ni-treated plants. SA or NO, especially both together considerably reduced root-to-shoot translocation of Ni and increased the activities of the antioxidant enzymes in leaves of Ni-stressed plants. Interaction of SA and NO improved the chlorophyll content and decreased the level of lipid peroxidation, H₂O₂ and proline accumulation in leaves. These results suggest that SA or NO in particular their combination counteract the negative effects of Ni on canola plants.  相似文献   

Genetic dissection of heading date and yield under Mediterranean dry climate in barley (Hordeum vulgare L.)     

Elahe Tavakol  Nader Elbadry  Alessandro Tondelli  Luigi Cattivelli  Laura Rossini 《Euphytica》2016,207(2):343-351

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The effect of soil texture on the water use efficiency of irrigated crops: Results of a multi-year experiment carried out in the Mediterranean region     

Nader Katerji  Marcello Mastrorilli 《European Journal of Agronomy》2009,30(2):95-100

The effect of soil texture on water use efficiency (WUE) was analyzed for six crops cultivated on loam and clay soils. Results were obtained after a long-term study, carried out in a lysimetric set-up, in conditions of experimental neutrality (climate, agro-techniques, and variety were the same for each crop) with the sole exception of the soil texture, which was the variable to be studied.In the case of potato, corn, sunflower, and sugar beet, WUE was reduced significantly when crops were grown in clay soil. The reductions ranged from 22% to 25%. The decrease of WUE in clay soil was coupled with significant reductions in yield and in ET, except in the case of the corn crop. The reduction in WUE in corn depended solely on the yield decrease.A 10% decrease in WUE values was also observed for the soy-bean and tomato grown in clay soil, but it was not statistically significant.Different causes which may reduce the WUE values observed in the clay soil are discussed. It seems coherent to hypothesize that, during the active growing phase, a deficit in water uptake occurs in the plants growing in the clay soil. This hypothesis is consistent with the observations of stomatal conductance, daily evapotranspiration, and leaf surface.In conclusion, the operative development of this study is outlined.  相似文献   

Differences in susceptibility to Haemophilus parasuis infection in pigs   总被引：1，自引：0，他引：1       下载免费PDF全文

Isabel Blanco  Ana Canals  Gary Evans  Martha A. Mellencamp  Carmen Cia  Nader Deeb  Lizhen Wang    Lucina Galina-Pantoja 《Canadian journal of veterinary research》2008,72(3):228-235

In animal breeding programs, deoxyribonucleic acid (DNA) markers can be used to identify sires that are less susceptible to disease. These DNA markers are typically discovered in populations that display differences in susceptibility. To find those differences, it was hypothesized that sires influence their offspring responses to infection with H. parasuis. To identify differences in susceptibility, colostrum-deprived pigs derived from 6 sires were inoculated with a virulent strain of H. parasuis serovar 5. Pigs were infected at 21-d of age and euthanized 1, 2, or 3 days post-infection. Rectal temperatures, bacterial detection, clinical signs, and lesions were measured by comparing disease susceptibility in the offspring from each sire. The effect of the sire on the severity of disease in the offspring was statistically analyzed using to a 2-way ANOVA with sire and test day as fixed effects. Significant differences among sires were found for lesions, rectal temperatures from days 0-1 and 0-2 (P < 0.05) and marginal effects for clinical signs (P = 0.08). On average, the offspring of sire H94 was the most susceptible to challenge. Responses to infection were categorized to determine the clinical responses and analyzed by Chi square. Overall, 10% of all pigs infected were fully resistant to H. parasuis infection. Boar H94 didn't produce any fully resistant offspring. Differences in susceptibility to H. parasuis were observed, and the results support the hypothesis that sires influence their offspring's response to infection. Tissues from this population could be used to identify DNA markers for genetic selection of sires that produce offspring more resistant to H. parasuis infection.  相似文献   

Effect of integrated management on Fusarium wilt progression and grain yield of chickpea in Syria     

Seid Ahmed Kemal  Mathew Abang  Muhammad Imtiaz  Asaad Nader 《Archives of Agronomy and Soil Science》2013,59(11):1551-1560

Fusarium wilt, caused by Fusarium oxysporum Schlechtend.: f. sp. ciceris (Padwick) Matuo & K. Sato, is a major production problem in many countries. A study was conducted to develop an integrated management of Fusarium wilt of chickpea using genotypes, sowing dates (January as early sowing and March/April as spring sowing) and fungicide seed treatments under natural infested plots in research plots and farmers’ fields 2007–2009 cropping seasons. In most cases, sowing date and fungicides did not affect disease parameters and seed yield. Chickpea genotypes showed significant differences in seed yield but different responses for disease parameters. Averaged over locations and seasons, the rate of disease development was higher in early (0.035 units day^?1) than spring (0.023 units day^?1) sowing. Chickpea genotypes showed different responses in affecting rate of disease development and cumulative wilt incidence in early and late sowing periods. Higher mean seed yield (1.3 t ha^?1) was recorded in early than late sowing (1.0 t ha^?1) of chickpea. The average seed yield reduction due to spring sowing ranged from 9% to 60% and highest yield losses were observed in FLIP-97–706 and Ghab-3. This study showed that integrating January sowing with genotypes having good levels of resistance for Fusarium wilt and Ascochyta blight helps farmers to narrow chickpea yield gaps in Syria.  相似文献   

Applied physics. Antenna-guided light     

Engheta N 《Science (New York, N.Y.)》2011,334(6054):317-318

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Acceleration of emergence of bacterial antibiotic resistance in connected microenvironments     

Zhang Q  Lambert G  Liao D  Kim H  Robin K  Tung CK  Pourmand N  Austin RH 《Science (New York, N.Y.)》2011,333(6050):1764-1767

The emergence of bacterial antibiotic resistance is a growing problem, yet the variables that influence the rate of emergence of resistance are not well understood. In a microfluidic device designed to mimic naturally occurring bacterial niches, resistance of Escherichia coli to the antibiotic ciprofloxacin developed within 10 hours. Resistance emerged with as few as 100 bacteria in the initial inoculation. Whole-genome sequencing of the resistant organisms revealed that four functional single-nucleotide polymorphisms attained fixation. Knowledge about the rapid emergence of antibiotic resistance in the heterogeneous conditions within the mammalian body may be helpful in understanding the emergence of drug resistance during cancer chemotherapy.  相似文献