Novel impacts of nanoparticles on soil properties: tensile strength of aggregates and compression characteristics of soil

Nanoparticles (NPs) affect most soil properties but there have been no assessments of their effects on the compression behavior of soil and the strength of aggregates. Therefore, we assessed the impact of NPs on the bulk density and the confined compression and tensile strength of aggregates of a calcareous loamy soil. Using a factorial design, we assessed the effects of two factors on the soil properties, i.e., NP type (first factor) at two levels comprising Fe nano-oxide (Fe₃O₄, N₁) and Mg nano-oxide (MgO, N₂), and treatment amount (second factor) at four levels with dry mass percentages of 0%, 1%, 3%, and 5%. The soil bulk density increased with the Fe level but decreased with the Mg level in ranges of 0.02–0.04 and 0.02–0.08 g cm^–3, respectively. The compression curve characteristics were not affected by the NPs. Compared with N₁, the N₂ treatment significantly increased the soil void ratio in 86% of the applied stresses. N₁ also significantly enhanced the soil tensile strength at suctions of 30, 100, and 1500 kPa, ranging from 0.5 to 15.3 kPa. The 3% Mg and 1% Fe dosages of nano-oxides had the optimal effects, so they should be considered in future investigations.     

Cardinal temperatures for seed germination of wild barley,barley grass and hoary cress

It is necessary to understand the effects of environmental conditions, especially temperature, on weed seed germination patterns, in order to make comprehensive and effective weed management decisions. The effect of cardinal temperature (0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C and 40°C) on the germination pattern of three noxious weeds, such as wild barley (Hordeum spontaneum Koch.), barley grass (H. murinum L.) and hoary cress (Cardaria draba L.) in wheat fields of Iran, was studied in three separate experiments. The experiments were conducted based on completely randomized design (CRD) with four replications. The result showed that the germination of all three species started at low temperatures and there was no significant difference in germination percentage (GP) at lower temperatures. About 50% of the weed population germinated within a short period when using a dent-like model indicating the high ability of these weeds to compete for space and resources. Segmented and dent-like models were used to evaluate the cardinal temperatures. The results showed that dent-like model was the preferred model to evaluate germination rate in relation to variable temperatures in hoary cress, while the segmented model was better in wild barley. However, there was no significant difference between the two models for barley grass. The results of this study showed that mechanical, cultural (pre-planting irrigation) and chemical practices could be more useful and effective at 10–30°C.     

Glutathione foliar fertilisation prevents lime‐induced iron chlorosis in soil grown Medicago scutellata

It has been proposed that glutathione can relieve the effects of Fe deficiency. This study tested the effects of glutathione foliar treatments to prevent Fe chlorosis, using as positive controls soil and foliar Fe fertilisation. Medicago scutellata plants were grown in soil (5.7% CaCO₃) supplemented or not with 4 and 8% CaCO₃. Two Fe(III)‐EDDHA soil treatments (5 and 10 mg Fe kg^?1), and three foliar treatments (three applications each of 2.14 mM Fe(III)‐EDDHA, 1 mM glutathione, and the previous two combined) were applied. Measurements include leaf chlorophyll and Fe concentrations, biomass, leaf enzymatic and non‐enzymatic antioxidant systems and carboxylates. The addition of CaCO₃ caused typical Fe deficiency symptoms, including changes in chlorophyll, Fe, antioxidant systems and carboxylates, which were prevented by soil and foliar Fe fertilisation. The foliar treatment with glutathione also led to higher chlorophyll, leaf extractable Fe and root Fe, as well as decreases in some antioxidant systems, whereas leaf Fe concentrations decreased. The combined foliar application of glutathione and Fe was even more efficient in preventing chlorosis. Including glutathione in foliar fertilisation programs should be considered as an option for Fe chlorosis prevention, especially when relatively large leaf total Fe concentrations occur in the so called chlorosis paradox.     

Development of a monoclonal blocking ELISA for the detection of antibody to Mycoplasma bovis in dairy cattle and comparison to detection by PCR

A monoclonal antibody blocking enzyme-linked immunosorbent assay (B-ELISA) was developed to detect antibodies to Mycoplasma bovis in cattle sera. The assay was highly specific and sensitive and there was no cross-reaction detected. This method revealed a high prevalence of antibodies (60%) to M. bovis in dairy cattle in North Queensland. The diagnostic potential of this B-ELISA for the detection of antibody to M. bovis was compared with its detection by PCR. There was a strong positive correlation between PCR and B-ELISA titers. Thus, the B-ELISA appears to be a valuable and reproducible tool in the serodiagnosis of M. bovis infection in cattle.     

A Class IV Chitinase Is Up-Regulated by Fungal Infection and Abiotic Stresses and Associated with Slow-Canker-Growth Resistance to Cronartium ribicola in Western White Pine (Pinus monticola)

ABSTRACT In the present study, in a candidate gene approach, a class IV chitinase gene (PmCh4A) of pathogenesis-related family three was cloned and characterized in western white pine (Pinus monticola). PmCh4A chitinase expression in the different organs of healthy seedlings was below levels detectable by western immunoblot analysis using an antibody raised against PmCh4A protein. However, a 27-kDa isozyme of PmCh4A accu mulated in both susceptible and slow-canker-growth (SCG) resistant seedlings after infection by Cronartium ribicola. As with fungal infection, the application of a signal chemical (methyl jasmonate) and a protein phosphatase 1 and 2A inhibitor (okadaic acid) increased the PmCh4A protein accumulation. Furthermore, another 26-kDa isozyme was expressed specifically in SCG resistant seedlings, providing a potential tool for marker-assisted selection in forest breeding. Wounding treatment also induced expression of the protein. These data suggest that the class IV chitinase PmCh4A is involved in the defense response of western white pine to infection and abiotic stresses.     

Wide genetic diversity of Rosa damascena Mill. germplasm in Iran as revealed by RAPD analysis

The genetic relationships among 41 Rosa damascena accessions from various cultivation areas of Iran and one accession from Bulgaria were analyzed using 31 RAPD (Randomly Amplified Polymorphic DNA) primers. Each primer exhibited 3–12 banding patterns for a total of 343 scorable and 184 polymorphic bands. The combination of 11 primers was found optimal for discrimination of 42 accessions with very low values of cumulative confusion probability (9.7 × 10⁻⁵); indicating that only one pair from over 10,000 distinct pairs of accessions would be indistinguishable. Unweighted pair group method cluster analysis based on similarity values revealed 10 groups at the distance of 0.85. The Bulgarian genotype grouped with the majority of the Iranian genotypes in a main cluster. Results of molecular variance analysis (AMOVA) indicated that the major proportion (65.7%) of the total genetic variation was within collecting provinces rather than between them. The wide genetic variation seen for R. damascena in Iran indicates that Iran is a center of genetic diversity for this species and that there is a promising future for the breeding.     

Comparison of Caudal Epidural Anesthesia with Lidocaine-distilled Water and Lidocaine-MgSO4 Mixture in Horses

This study was performed to compare the onset and duration of analgesia produced by either a lidocaine−MgSO₄ or lidocaine−distilled water combination administration in the caudal epidural space of horse. Seven healthy adult horses, aged 11.7 ± 1.4 years (mean ± SD), body weight (kg) 567 ± 32.5 (mean ± SD), were selected for this study. Caudal epidural anesthesia was produced in all horses by administering 2% lidocaine (0.22 mg/kg) diluted in 1 mL distilled water and repeated with 2% lidocaine (0.22 mg/kg) diluted in 1 mL 10% MgSO₄ 2 weeks later. Time to onset (minutes), duration (minutes), and cranial spread of epidural analgesia were recorded. Heart rate (HR), respiratory rate (RR), and body temperature (°C) were recorded. Measurements were taken at 0 (as a baseline value before epidural administrations) and at 5, 10, 15, 30, 60, and 75 minutes after the epidural administrations of each treatment. Statistical analyses included paired Student t test and analysis of variance (computer program SPSS, Analytical Software, version 15.00). Statistical significance was set at P < .05. Onset of analgesia was significantly different (P < .001) between lidocaine-distilled water (2.38 ± 0.47 minutes) and lidocaine−MgSO₄ (4.62 ± 0.54 minutes). Duration of analgesia after lidocaine−MgSO₄ (186.0 ± 7.0 minutes) was longer than lidocaine-distilled water (54.5 ± 7.3 minutes). No significant differences were recorded for HR, RR, and body temperature in comparison with baseline values for each group. Using the lidocaine−MgSO₄ combination for obstetric and surgical procedures could commence relatively soon after epidural injection and could be completed without readministration of anesthetic agent.     

Trypsin Enzyme from Viscera of Common Kilka (Clupeonella cultriventris caspia): Purification,Characterization, and Its Compatibility with Oxidants and Surfactants

The purification of trypsin from the common kilka (Clupeonella cultriventris caspia) viscera (pyloric caeca) resulted in a 28.3-fold increase and 12% yield by ammonium sulfate precipitation (30–60%), Sephadex G-75, and DEAE-cellulose chromatography. Trypsin showed a molecular weight of 23.2 kDa and appeared as a single band on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), native-PAGE, and zymography. The trypsin had optimal activity at pH 8.0 and 60°C for the hydrolysis of α-N-benzoyl-DL-arginine-ρ-nitroanilide hydrochloride (BAPNA) substrate. Trypsin was stable up to 50°C and at pH range of 7.0–10.0. Activity was significantly inhibited by soybean trypsin inhibitor (SBTI) and N-ρ-tosyl-L-lysine-chloromethylketone (TLCK) inhibitors (p < 0.05). The enzyme was relatively stable toward oxidizing agents, retaining 59.7 and 98.0% of its initial activity after 1 h incubation in the presence of 15% H₂O₂ and 1% sodium perborate, respectively. Trypsin was significantly activated by surfactants and Ca²⁺, Mg²⁺, and Mn²⁺ and inactivated by Fe²⁺, Zn²⁺, Cu²⁺, Al³⁺, Ba²⁺, and Co²⁺ (p < 0.05). Nevertheless, Na⁺ and K⁺ had no significant effect on trypsin activity (p > 0.05). The purified trypsin showed significantly higher catalytic efficiency (k_cat/K_m) than porcine pancreatic trypsin against BAPNA and N-α-p-Tosyl-L-arginine methyl ester hydrochloride (TAME) substrates (p < 0.05).