Improvement of biochar capability in Cr immobilization via modification with chitosan and hematite and inoculation with Pseudomonas putida

ABSTRACT

Modification of biochar using chitosan and hematite made the biochar product more effective for hexavalent chromium (Cr (VI)) reduction in contaminated soils. Release experiment was conducted to examine Cr (VI) reduction in different treatments (control, unmodified biochar and two modified biochars with chitosan or hematite). The results indicated that the application of all treatments significantly decreased the release rate of Cr in comparison to the control treatment. Chitosan-modified biochar application increased Cr (VI) reduction from 28.53% (biochar) to 46.23%. In the case of hematite-modified biochar, it increased Cr (VI) reduction from 28.55% (biochar) to 38.95%. Two kinetic equations including pseudo-first-order and pseudo-second-order models employed to describe the time-dependent Cr release data. Between the kinetic equations estimated, the pseudo-second order best fitted to experimental data. In the presence of Pseudomonas putida, cumulative Cr release rate decreased by 2.38 mg kg^?1 (50.29%) in hematite–biochar and 1.768 mg kg^?1 (39.73%) in unmodified biochar as compared with control (4.43 mg kg^?1). According to results reported herein, modification of biochar with chitosan or hematite is promising since made biochar more effective in removing Cr from Cr-polluted calcareous soils.     

Seed retention of ten common weed species at oat harvest reveals the potential for harvest weed seed control

We assessed the seed production and shedding pattern of 10 common weed species in two oat fields in Denmark. The aim was to evaluate the possibility of harvesting retained seeds on weeds at crop harvest by a combine harvester based on estimation of weed seed retention. Before flowering, ten plants of each weed species were selected and surrounded by a seed trap comprising of a porous net. When the plants started shedding seeds, the seeds were collected from the traps and counted weekly until oat harvest. Just before oat harvest, the retained seeds on the plants were counted and the ratio of harvestable seeds and shed seeds during the growing season was determined. The seed production and shedding patterns varied between the 2 years. Across both years, Anagallis arvensis L., Capsella bursa-pastoris L. Medik, Chenopodium album L., Geranium molle L., Persicaria maculosa Gray, Polygonum aviculare L., Silene noctiflora L., Sonchus arvensis L., Veronica persica Poir. and Viola arvensis Murray retained on average 61.6%, 52.7%, 67.2%, 58.4%, 32.05%, 59.5%, 95.7%, 23.5%, 51.7% and 33.9%, respectively, of their produced seeds at crop harvest. Silene noctiflora was classified as a good target for harvest weed seed control; C. bursa-pastoris, C. album, G. molle, P. maculosa, S. arvensis and V. arvensis were classified as intermediate targets; and A. arvensis, P. aviculare and V. persica were classified as poor targets.     

Effects of Different Dietary Lipid Sources on Growth Performance,Fatty Acid Composition,and Antioxidant Enzyme Activity of Juvenile Rockfish,Sebastes schlegeli

This study was carried out to investigate and compare the effects of various dietary lipid sources on growth performance, body composition, fatty acid profiles, and hepatic and plasma antioxidant enzyme activities of juvenile rockfish, Sebastes schlegeli. Three replicate groups of fish (initial mean weight, 1.7 ± 0.04 g) were fed four isonitrogenous and isolipidic diets containing either fish oil (FO), soybean oil (SO), linseed oil (LO), or a mixture of SO and LO (SO + LO) for 8 wk. There were no significant differences in survival, weight gain, feed efficiency, and protein efficiency ratios of fish fed the diets containing different lipid sources (P > 0.05). The fatty acids compositions of the liver and muscle tissues reflected the dietary fatty acid compositions. Liver and muscle of fish fed the SO diet had high concentration of linoleic acid, whereas those of fish fed the LO diet were rich in linolenic acid. Liver and muscle of fish fed the FO diet had significantly (P < 0.05) higher levels of eicosapentaenoic acid and docosahexaenoic acid than those of fish fed the SO and LO diets. Dietary lipid source had no significant effect on the hepatic and plasma enzyme activities of superoxide dismutase and glutathione peroxidase. The results of this study suggest that SO and LO can be used as a replacement for FO in the diets of juvenile rockfish without incurring any negative effects on growth, feed utilization, and antioxidant enzyme activity, when the dietary essential fatty acid requirements are satisfied for rockfish.     

Investigating the effects of temperature on seed germination of cutleaf geranium (Geranium dissectum L.) and determination of its cardinal temperatures

Phytoparasitica - Cutleaf geranium is a weed infesting crop fields in various parts of the world. The present study was conducted to determine the cardinal temperatures of germination for its seeds...     

Effect of growth regulators and explant on plant regeneration of Solanum lycopersicum L. var. cerasiforme

Tomato serves as a model to introduce agronomically important genes into dicotyledonous crop plants and to develop edible vaccines and produce cost-effective therapeutics. This study has developed an efficient protocol of shoot organogenesis for Lycopersicon esculentum Mill. through using of different types of explants and growth regulators. Generally, all explants responded significantly to presence of BAP. Best shoot regeneration for leaf (100%) was achieved on MS supplemented with BAP (2 mg/L) + IAA (0.1 mg/L), whereas it was recorded on MS supplemented with BAP (2 mg/L) and BAP (2 mg/L) + IAA (0.5 mg/L) for cotyledons (95%). In addition, hypocotyls (77%) showed the best shoot response on MS supplemented BAP (3 mg/L). Highest number of shoots per explant was 13.33, 12.25, 7.94 respectively for hypocotyls, leaves, cotyledons. The best medium for highest length of shoot was in the presence of BAP (3 and 2 mg/L) + IAA (0.1 mg/L) respectively for hypocotyl (45 mm) and leaf (40.50 mm) explants. This parameter was achieved for cotyledons (13.32 and 12.5 mm) on MS medium supplemented with BAP (3 and 2) mg/L + IAA (0.1 mg/L), respectively. The increasing of BAP concentration up to 3 (mg/L) causes shoot length to continue developing, but it fell down in the presence of BAP (4 mg/L) due to the toxic effect of growth regulators accumulation. Root formation took place within 10–14 days after culturing on the rooting media. Best root induction (100%) was observed on MS medium supplemented with IAA (0.1 and 0.2 mg/L). All rooted shoots acclimated in phytotron and then cultivated in the greenhouse.     

Full-genome characterization and genetic analysis of a H9N2 virus in commercial broilers in Iran, 2017

Tropical Animal Health and Production - Since 1998, Iran’s poultry industry has faced several outbreaks of low pathogenic avian influenza H9N2. Tissue samples were collected from a broiler...     

Plasma and urine pharmacokinetics of intravenously administered flunixin in greyhound dogs

Medication control in greyhound racing requires information from administration studies that measure drug levels in the urine as well as plasma, with time points that extend into the terminal phase of excretion. To characterize the plasma and the urinary pharmacokinetics of flunixin and enable regulatory advice for greyhound racing in respect of both medication and residue control limits, flunixin meglumine was administered intravenously on one occasion to six different greyhounds at the label dose of 1 mg/kg and the levels of flunixin were measured in plasma for up to 96 hr and in urine for up to 120 hr. Using the standard methodology for medication control, the irrelevant plasma concentration was determined as 1 ng/ml and the irrelevant urine concentration was determined as 30 ng/ml. This information can be used by regulators to determine a screening limit, detection time and a residue limit. The greyhounds with the highest average urine pH had far greater flunixin exposure compared with the greyhounds that had the lowest. This is entirely consistent with the extent of ionization predicted by the Henderson–Hasselbalch equation. This variability in the urine pharmacokinetics reduces with time, and at 72 hr postadministration, in the terminal phase, the variability in urine and plasma flunixin concentrations are similar and should not affect medication control.     

The pharmacokinetics of pimobendan enantiomers after oral and intravenous administration of racemate pimobendan formulations in healthy dogs

Pimobendan is a benzimidazole‐pyridazinone derivative, marketed as a racemic mixture for the management of canine heart failure. Pharmacokinetics of the enantiomers of pimobendan and its oral bioavailability have not been described in dogs. The aim of this study was to describe pharmacokinetics of three formulations of pimobendan in healthy dogs: the licensed capsule product, and novel liquid and intravenous formulations. A three‐period, nested randomized two‐treatment crossover design was used. Pimobendan was administered p.o. at 0.25 and i.v. at 0.125 mg/kg. Blood and plasma samples were analysed by liquid chromatography–mass spectrometry. Noncompartmental modelling was used to describe the pharmacokinetics. Parameters were compared between formulations using a general linear model. Bioequivalence of the oral formulations was tested using CI90 for AUC_(0–∞) and C_max. Bioavailability of pimobendan after oral dosing was 70%. Liquid and capsule formulations were bioequivalent only for AUC. The positive enantiomer of pimobendan (PE) had a larger volume of distribution than the negative enantiomer (NE) (281 ± 48 vs. 215 ± 68 mL/kg; P = 0.003) and a shorter half‐life (21.7 vs. 29.9 min; P = 0.004). The NE was distributed more quickly than the PE into blood cells. Enantiomers of pimobendan have differing absorption, distribution and elimination. The pharmacokinetics of pimobendan in healthy dogs was described.     

Evaluation of kernel yield and agronomic traits of European maize hybrids in the temperate region of Iran

The production of locally adapted maize hybrids requires parental material with adequate genetic variation in the relevant traits. The objective of the present study was to evaluate 20 European maize hybrids under temperate region for their potential use in direct cultivation or as parent material in local breeding programs. Results showed that European hybrids except BC 566 had higher kernel yield (11.4–14.3 t ha^?1) than local cultivars (KSC705 and KSC704). Korimbos, Krebs, BC 566, and BC 532 had lower kernel moisture (14–15%) compared to KSC705 (21.7%) and KSC704 (22.7%). Cluster analysis categorized these hybrids in three groups. Cluster 2 comprised of Korimbos, BC 612, DKC 6589, and 89May70. These hybrids had high plant height, thousand kernel weight, and kernel yield. Due to high kernel moisture, the hybrid 89May70 could not be proposed for direct cultivation but it can be involved in transferring high grain yield to local hybrids. Genotype × environment analysis showed that Korimbos and Krebs had low S²_i and low genotypic coefficient of variation, high and stable performance and low kernel moisture. Therefore, Korimbos and Krebs can possibly be used for direct cultivation in temperate regions of the Fars Province.