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1.
The application of soil amendments to immobilize heavy metals is a promising technology to meet the requirements for environmentally sound and cost‐effective remediation. The present study was carried out to evaluate the result of phosphogypsum (PG) used alone and in combination with compost (CP) at a mix ratio of 1:1 wet weight ratio (PG + CP) at 10 and 20 g dry weight kg−1 dry soil, on heavy metal immobilization in contaminated soil and on canola growth. The results revealed that the Pb, Cd and Zn uptake of canola plants was reduced by the application of PG alone and when it was mixed with CP as compared with untreated soil. At an application rate of 10 g dry weight kg−1 dry soil of (PG + CP) the dry weight of canola plants increased by 66·8% was increased in comparison with its weight in the untreated soil. The addition of PG alone resulted in more pronounced immobilization of heavy metal as compared with PG mixed with CP. Plant growth was improved with CP addition, but heavy metals immobilization was the greatest in PG alone treatments. Results suggest that PG may be useful for the immobilization of heavy metals in contaminated soils. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
2.
Virucidal efficacy of four new disinfectants   总被引:5,自引:0,他引:5  
Virucidal efficacy was evaluated for four recently available disinfectants: chlorine dioxide, potassium peroxymonosulfate, a quaternary ammonium compound, and citricidal (grapefruit extract). Sodium hypochlorite (3%) and tap water were used as positive and negative controls respectively. Feline herpesvirus, feline calicivirus, and feline parvovirus were exposed to the manufacturers' recommended dilutions of the evaluated disinfectants. Both chlorine dioxide and potassium peroxymonosulfate completely inactivated the three viruses used in this study. These disinfectants can aid in controlling nosocomial transmission of viruses with less of the deleterious effects of sodium hypochlorite. The quaternary ammonium compound evaluated in this study and citricidal were not effective against feline calicivirus and feline parvovirus.  相似文献   
3.
The effects of high temperature stress and supplemental irrigation on seed yield and water use efficiency (WUE) of canola (Brassica napus L.) were studied in a field experiment conducted for 2 years. The experiment was a randomized complete block design arranged in split plot, conducted at Agricultural Research Station of Gonbad, Iran. It was arranged in two conditions, i.e. supplemental irrigation and rainfed. Two cultivars of canola (Hyola401 and RGS003) as subplots were grown at five sowing dates as main plots. The sowing dates were 9 November, 6 December, 5 January, 4 February and 6 March in 2005-2006 and 6 November, 6 December, 5 January, 4 February and 6 March in 2006-2007, to have a wide range of environmental conditions around flowering and seed filling periods, and to coincide reproductive stages of the crop with high temperature stress. Seed yield was improved due to field management practices, such as supplemental irrigation and optimum sowing date. Supplemental irrigation was an efficient practice to mitigate water stress, and to increase aboveground dry matter and seed yield. There was a strongly negative relationship between seed yield and air temperature during reproductive stages. Delay in sowing led to more rapid developmental of canola, decreased aboveground dry matter, leaf area index (LAI), harvest index (HI), WUE, and seed yield. Achieving a high aboveground dry matter was an essential prerequisite for high reproductive growth and a high seed yield. Greater seed yield and WUE at first sowing date were associated with greater LAI and aboveground dry matter, and lower temperatures during reproductive stages. The results support the view that WUE can be used as an indirect selection criterion for seed yield in genotypic selection.  相似文献   
4.
To characterize canine coronavirus (CCoV) circulating in diarrheic puppies in Brazil, 250 fecal samples collected between 2006 and 2012 were tested. By using RT-PCR to partially amplify the M gene, CCoV RNA was detected in 30 samples. Sequence analysis of the M protein grouped eight strains with CCoV-I and another 19 with CCoV-II prototypes. To genotype/subtype the CCoV strains and assess the occurrence of single or multiple CCoV infections, RT-PCR of the S gene was performed, and 25/30 CCoV-positive strains amplified with one or two primer pairs. For 17/25 samples, single infections were detected as follows: six CCoV-I, nine CCoV-IIa and two CCoV-IIb. Eight samples were positive for more than one genotype/subtype as follows: seven CCoV-I/IIa and one CCoV-I/IIb. Sequence analysis revealed that the CCoV-I and IIa strains shared high genetic similarity to each other and to the prototypes. The Brazilian strains of CCoV-IIb displayed an aminoacid insertion that was also described in CCoV-IIb-UCD-1 and TGEV strains. Among the 25 CCoV-positive puppies, five had a fatal outcome, all but one of which were cases of mixed infection. The current study is the first reported molecular characterization of CCoV-I, IIa and IIb strains in Brazil.  相似文献   
5.
Two infectious tenosynovitis-producing viruses were isolated from tendon sheaths and synovial fluids of 59 broilers and 15 broiler breeders obtained from different flocks in Egypt during June to October 1983. The viruses grew well on the chorioallantoic membrane of developing chicken embryos, produced small localized white pock lesions with oedematous swellings at the inoculation sites and death of most of the embryos 72 to 96 hours post-inoculation. They also induced cytopathic effect in chicken embryo rough, Vero and MS cell lines. The viruses were neutralized by reovirus S1133 antiserum, both in tissue culture and. on the chorioallantoic membrane. Inoculation of the viruses into 2-day-old broiler chicks via the foot pad, intramuscular and oral routes reproduced the disease with the development of characteristic clinical, pathological and serological responses. The infection was transmitted to in-contact control chicks. This is the first report of the disease and of the isolation and identification of the causative virus in Egypt.  相似文献   
6.
Two infectious tenosynovitis-producing viruses were isolated from tendon sheaths and synovial fluids of 59 broilers and 15 broiler breeders obtained from different flocks in Egypt during June to October 1983. The viruses grew well on the chorioallantoic membrane of developing chicken embryos, produced small localized white pock lesions with oedematous swellings at the inoculation sites and death of most of the embryos 72 to 96 hours post-inoculation. They also induced cytopathic effect in chicken embryo rough, Vero and MS cell lines. The viruses were neutralized by reovirus S1133 antiserum, both in tissue culture and on the chorioallantoic membrane. Inoculation of the viruses into 2-day-old broiler chicks via the foot pad, intramuscular and oral routes reproduced the disease with the development of characteristic clinical, pathological and serological responses. The infection was transmitted to in-contact control chicks. This is the first report of the disease and of the isolation and identification of the causative virus in Eqypt.  相似文献   
7.
Soil particle size distribution (PSD) is a fundamental physical property affecting other soil properties. Characterizing spatial variability of soil texture is very important in environmental research. The objectives of this work were: 1) to partition PSD of 75 soil samples, collected from a flat field in the University of Guilan, Iran, into two scaling domains using a piecewise fractal model to evaluate the relationships between fractal dimensions of scaling domains and soil clay, silt, and sand fractions and 2) to assess the potential of fractal parameters as an index used in a geostatistical approach reflecting the spatial variability of soil texture. Features of PSD of soil samples were studied using fractal geometry, and geostatistical techniques were used to characterize the spatial variability of fractal and soil textural parameters. There were two scaling domains for the PSD of soil samples. The fractal dimensions of these two scaling domains (D1 and D2) were then used to characterize different ranges of soil particle sizes and their relationships to the soil textural parameters. There was a positive correlation between D1 and clay content (R2 = 0.924), a negative correlation between D1 and silt content (R2 = 0.801), and a negative correlation between D2 and sand content (R2 = 0.913). The geometric mean diameter of soil particles had a negative correlation with D1 (R2 = 0.569) and D2 (R2 = 0.682). Semivariograms of fractal dimensions and soil textural parameters were calculated and the maps of spatial variation of D1 and D2 and soil PSD parameters were provided using ordinary kriging. The results showed that there were also spatial correlations between D1 and D2 and particle size fractions. According to the semivariogram models and validation parameters, the fractal parameters had powerful spatial structure and could better describe the spatial variability of soil texture.  相似文献   
8.
Tropical Animal Health and Production - This research was conducted to determine the prevalence and intensity of infection with nymphs of Linguatula serrata in mesenteric lymph nodes of the goats...  相似文献   
9.
Physically based equations for unsaturated groundwater flow and solute transport have been coupled with kinetic rate laws for mineral dissolution–precipitation, and mass balance/mass action equations for aqueous species, in a numerical model that is capable of simulating rock–water interactions in a weathering profile subjected to fluctuating boundary conditions. A numerical experiment was conducted to demonstrate how incipient soil development may proceed in a warm subhumid environment. The simulation involved a hypothetical coarse-textured parent material that was subjected to frequent wetting and drying during an annual water cycle. The hypothetical weathering profile evolved rapidly; dissolution of primary minerals (enstatite, forsterite, and diopside) and precipitation of secondary clay–minerals (kaolinite and Ca-montmorillonite) occurred monotonically despite the abrupt fluctuations in soil-moisture content. In contrast, the activities of aqueous species and dissolution–precipitation rates of calcite were very sensitive to the changing moisture conditions in the upper part of the profile. Although the simulation involved numerous simplifying assumptions, reasonable results were achieved and the calculated (from the model) rate of chemical denudation fell within the range of contemporary denudation rates determined from the dissolved loads of rivers.  相似文献   
10.
The present work was performed to assess whether soybean meal (SBM) could replace fish meal (FM) as a source of dietary protein in diets of the marine herbivore Siganus rivulatus. Five iso-nitrogenous (40% protein) and iso-energetic (14 MJ/Kg) diets were prepared with SBM replacing fish meal at 0%, 25%, 50%, 75%, and 100% dietary protein. A 60-day feeding trial was conducted with 240 juvenile S. rivulatus (initial body mass 1.74 ± 0.03 g). Survival, growth, feed, and protein efficiency and hematological parameters were assessed. Growth correlated negatively with increase in dietary SBM. All production parameters measured were negatively affected at all levels of SBM inclusion. There were no effects on total or differential blood counts, hemoglobin, or plasma protein, but hematocrit values were negatively correlated with SBM addition. Results suggest that total replacement of FM by SBM without adding other supplements is not recommended, even for an herbivorous marine fish such as S. rivulatus.  相似文献   
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