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101.
In this study, viral pathogens associated with nine outbreaks of naturally occurring dairy calf pneumonia in Mashhad area
of Khorasan Razavi province from September 2008 to May 2009 were assessed. Five diseased calves from each farm were chosen
for examination. Acute and convalescent serum samples were taken from calves with signs of respiratory disease. Sera were
analyzed for antibodies to bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BHV-1), bovine respiratory syncytial
virus (BRSV), parainfluenza virus type 3 (PI-3V), and bovine adenovirus-3 (BAV-3) by indirect ELISA kits. Among 42 serum samples
collected at sample 1, seroprevalence values for viruses BHV-1, BVDV, BRSV, PI-3V, and BAV-3 were 61.9% (26), 57.1% (24),
64.2% (27), 90% (38), and 61.9% (26), respectively. Seroconversion to BVDV, BRSV, PI-3V, and BAV-3 occurred in 11.9% (5),
16.6% (7), 26.1% (11), and 21.4% (9) of animals, and 52.3% (22) had generated antibodies against one or more viral infections
at sample 2. In addition, no significant relationship between seroprevalence of BHV-1, BVDV, BRSV, PI-3V, and BAV-3 and dairy
herd size was observed (P > 0.05). According to serological findings, BHV-1, BVDV, BRSV, PI-3V, and BAV-3 are common pathogens of the dairy calf pneumonia
in dairy herds in Mashhad area of Khorasan Razavi province, Iran. 相似文献
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104.
Sayed Zia Mohammadi Tahereh Rohani Leila Bahadori 《Communications in Soil Science and Plant Analysis》2017,48(11):1359-1368
In the present work, magnetic iron oxide nanoparticles (MIONPs) coated with sodium dodecyl sulfate (SDS) and modified with 1-(2-pyridylazo)-2-naphthol (PAN) as a new nanoparticle were prepared and used as an adsorbent for the extraction and preconcentration of copper ions. After adsorption, copper ions were desorbed with nitric acid (HNO3), followed by determination with flame atomic absorption spectrometry (FAAS). The extraction conditions0. were investigated systematically. The linear range 3.0–500.0 ng mL?1 and the detection limit of 0.6 ng mL?1 were obtained. The relative standard deviation (RSD) of the method for seven replicate determinations of 0.1 µg mL?1 of Cu(II) was 2.2%. The method was applied for the determination of Cu(II) in different water samples with good trueness. The accuracy was also evaluated through analyses of a certified reference material (CRM TMDW-500). 相似文献
105.
Sayed Zia Mohammadi Daryoush Afzali Farzaneh Arabpour 《Communications in Soil Science and Plant Analysis》2017,48(21):2496-2505
In the present study, a method based on dispersive liquid–liquid microextraction (DLLME) followed by graphite furnace atomic absorption spectrometry (GFAAS) determination was proposed for the determination of selenium by using ammonium pyrrolidine dithiocarbamate (APDC) as the chelating reagent. The main factors influencing the DLLME were investigated systematically. Under the optimal conditions, the limit of detection for Se(IV) was 0.02 ng mL?1. The relative standard deviation was 4.1% (CSe(IV) = 0.2 ng mL?1, n = 8) with an enhancement factor of 135.8-fold from only 5 mL of the water sample. The proposed method was successfully applied to the determination of Se(IV) in anodic slime and electrolyte samples. In order to validate the proposed method, a Certified Reference Material (trace elements in water, 1643e, NIST) was analyzed, and the determined value obtained was in good agreement with the certified value. 相似文献
106.
The aim of this study was to estimate a basal area growth model for individual trees in uneven-aged Caspian forests. A survey was conducted in order to find a natural forest without any harvesting activities, a so called ‘untouched forest’ and an area was selected from the Iranian Caspian forest. Three sample plots in the same aspect and of the same forest type were selected. In each plot, total tree height, diameter at breast height, distance of neighbor trees and azimuth were measured. Thirty trees were selected and drilled with increment borer to determine the increment model. Regression analysis was used to estimate the growth model. Results show that, for individual trees, there is a significant nonlinear relationship between the annual basal area increment, as the dependent variable, and the basal area. The results also show that the basal area of competing trees has a positive influence on growth. That the increment is higher with more competing neighboring trees is possibly because plots with higher volume per hectare and more competition, most likely also have higher site index or better soil or better site productivity than the plot with lower volume per hectare. 相似文献
107.
Shahram Torabian Mohammad Reza Shakiba Adel Dabbagh Mohammadi Nasab Mahmood Toorchi 《Communications in Soil Science and Plant Analysis》2018,49(11):1289-1301
In order to investigate the effects of exogenous spermidine on water limitation-induced damage on common bean (Phaseolus vulgaris L.) genotypes, a field experiment was conducted over two growth seasons. The experiment was arranged as a split-split plot design and three replications. Treatments were three water stress levels (non-stress, moderate and severe stress), three bean genotypes (Akhtar, Pak and COS12) and two spermidine levels (control and foliar application). The results showed that water stress reduced markedly leaf relative water content, SPAD values, specific leaf area, leaf area index, plant height, relative growth rate, shoot dry weight and grain yield; however, increased leaf density, leaf relative electrolyte leakage, stomatal density, leaf angle and leaf temperature of bean genotypes. Spermidine application increased relative water content, SPAD values, leaf area, leaf area index, shoot dry weight and grain yield. Overall, exogenous spermidine usage as a free radical scavenger counteracted deleterious water deficit effects. 相似文献
108.
Mahmoud Roushani Yar Mohammad Baghelani Maryamosadat Mavaei Shahryar Abbasi Sayed Zia Mohammadi 《Communications in Soil Science and Plant Analysis》2018,49(6):645-657
In this study, cobalt magnetic nanoparticles (MNPs) were synthesized and then modified by sodium dodecyl sulfate (SDS) and 2-(5-bromo-2-pyridylazo)-5-diethyl aminophenol ligand (5-Br-PADAP), through a chemical precipitation method. Characterization of the prepared MNP adsorbents was performed by Fourier transform infrared and transmission electron microscopy. Cobalt nanoparticles (NPs) surface modified with SDS and 5-Br-PADAP was evaluated as a nanoparticulate solid-phase extraction (SPE) absorbent for lead ions Pb(II) from water and standard samples, prior to its flame atomic absorption spectrometry determination. Effects of pH, amount of sorbent, desorption solvent, adsorption time, desorption time, and interfering ion concentration on extraction efficiency were investigated. Under optimal conditions, the calibration curve was linear in the range of 1.0–500 ng mL?1of Pb(II) with R2 = 0.998. Detection limit was 1.6 ng mL?1 in the original solution (3Sb/m), and the relative standard deviation for replicate determination of 0.5 μg mL?1 Pb(II) was ±2.7%. 相似文献
109.
Rana Valizadeh-Kamran Mahmoud Toorchi Mohammad Mogadam Hamid Mohammadi 《Journal of plant nutrition》2018,41(1):102-111
An experiment was performed as a split-plot design based on a randomized complete block (RCB) with three replicates. The aim was to explore physiological traits, catalase (CAT) and peroxidase (POD) activity associated with cold and freeze stress in four barley genotypes (two stress-tolerant genotypes and two sensitive genotypes). The genotypes were regarded as sub-plots and five temperature levels (namely 20, 4, 0, ?4, ?8°C) as main plots. The results revealed that the hydrogen peroxide (H2O2) and malondialdehyde (MDA) content increased through freeze and cold stress from 20 to 4°C. This increase was more in the sensitive genotypes than in the tolerant ones. Subsequent to the increase in lipid peroxidation, the membrane stability index (MSI) decreased, thereby increasing the electrolyte leakage. The sensitive genotypes demonstrated greater reduction in the studied parameters. Upon the increase in the H2O2 content, the antioxidant enzymes CAT and POD also increased in order to collect and prevent H2O2 from damaging the cell and the plant. Compared with the sensitive ones, the tolerant genotypes indicated more increase in the enzymes. The H2O2 and MDA content decreased from ?4 to ?8°C, which could be due to intracellular freezing in the sensitive genotypes, but due to the detoxifying of the antioxidant enzymes in the tolerant genotypes. Compared with the POD content, the increase in the CAT content through cold stress was more, which could mean that it was possibly CAT which acted as the main inhibitor of H2O2 in cold stress in the barley plant. 相似文献
110.
Anahid Salmanpour Mohammad Hassan Salehi Jahangard Mohammadi 《Archives of Agronomy and Soil Science》2018,64(8):1106-1118
Neyriz area, on south of Neyriz ophiolite complex, is one of the most important areas in fruit production. However, no study has been yet performed to assess the contamination status of soils in this region. The objective of the present study was to explore soil pollution by Cr, Ni and Co. Three landforms (ophiolite hills, alluvial fan and playa) were selected along a transect. Seven pedons were excavated and soil and rock samples were obtained. The total concentration of Cr, Ni and Co, Enrichment Factor (EF) and Geo-accumulation index (Igeo) were determined. Results showed that soils over ophiolite hills and alluvial fan were extremely polluted by Cr and Ni (Igeo=3–6). The EF Index confirmed that heavy metals originated from ophiolite rocks in the region. Both indices showed a descending trend from ophiolite hills to playa that related to deposit transportation processes during landforms evolution. It was also observed a decreasing vertical trend in metal contents in the soils over alluvial fan which can be attributed to the long-time irrigation and plant uptake as affected by land use. Further investigation is needed to understand the contamination status of ground-water and orchards of the region to achieve sustainable management. 相似文献