Chicken-manure-derived biochar reduced bioavailability of copper in a contaminated soil

Purpose

Copper (Cu) contamination has been increasing in land ecosystems due to economic development activities. Excessive amount of Cu in soils is toxic to both plants and microorganisms. Biochar (BC) is known to immobilize soil Cu. The objectives of this research were to investigate the effects of chicken-manure-derived BC (CMB) on Cu immobilization, and growth of native metallophyte Oenothera picensis in a Cu-contaminated soil.

Materials and methods

A Cu-contaminated sandy soil (338 mg Cu kg^?1) was spiked and equilibrated with additional Cu (0, 100, and 500 mg Cu kg^?1). The spiked soil was then amended with CMB (0, 5, and 10 % w/w) and incubated for 2 weeks. The metallophyte was grown on these treatments under greenhouse conditions for 3 months. Pore water solutions were collected from the plant pots every 30 days. After the harvest, soil and pore water pH, soil Cu fractions, pore water Cu concentration, soil microbial activity, plant biomass weight, and Cu concentration in plant parts were determined.

Results and discussion

The CMB increased the pH of soils and soil pore water, and probably also soil major nutrients. It reduced the exchangeable fraction of Cu but increased its organic matter and residual fractions. At the same time, it decreased the Cu concentration in the soil pore water. The CMB increased basal respiration and dehydrogenase activity. The CMB application produced up to three and seven times more root and shoot biomass, respectively. In addition, shoots accumulated lesser Cu than control but roots did more. Plants survived in soil that was spiked with 500 mg Cu kg^?1, only when CMB dose was 10 %.

Conclusions

The CMB affected the Cu uptake in plant by altering the mobility, bioavailability, and spatial distribution of Cu in soils. The increase in available nutrients and decrease in Cu toxicity facilitated plant growth. The increased microbial activity probably also promoted the plant growth and reduced the Cu bioavailability. Therefore, CMB can be used to remediate Cu-contaminated soils.

     

Fall rate of burnt pines across an elevational gradient in a Mediterranean mountain

Burnt wood remaining after a wildfire is a biological legacy with important implications for habitat structure, ecosystem regeneration, and post-fire management. Knowledge of the time required for snags to fall is thus a key aspect for planning forest restoration. In this study, we analyze the fall rate of burnt trees in a Mediterranean pine reforestation. Three plots of 18–32 ha were established after a fire across an elevational gradient spanning from 1400 to 2100 m a.s.l., and snag fall rate was measured on a yearly basis using an experimental setup that considered two levels of a thinning treatment: unthinned (where no post-fire management was conducted and all the snags were left standing after the fire) and thinned (where 90% of the trees were cut after the fire and left on the ground). All the snags remained standing during the first and second winter, and thereafter, they collapsed quickly until reaching 100% after 5.5 years. Snags in low-density stands resulting from thinning fell faster than in unthinned stands, but the differences were minor. There was a negative effect of tree diameter on the rate of collapse, especially in the unthinned treatment, but the effect of diameter was minor too. There was no effect of the elevational gradient on fall rate despite patent differences in climatic conditions and pine species across plots. The results support the contention that post-fire fall rate in dense pine plantations in Mediterranean mountains can occur quickly after the second winter and may show little variation across environmental gradients.     

COMPUTED TOMOGRAPHIC FEATURES OF INCISOR PSEUDO‐ODONTOMAS IN PRAIRIE DOGS (CYNOMYS LUDOVICIANUS)

Maxillary incisor pseudo‐odontomas are common in pet prairie dogs and can cause progressive respiratory obstruction, while mandibular pseudo‐odontomas are rarely clinically significant. The aim of this retrospective cross‐sectional study was to describe CT features of maxillary and mandibular incisor pseudo‐odontomas vs. normal incisors in a group of pet prairie dogs. All pet prairie dogs with head CT scans acquired during the period of 2013–2015 were included. A veterinary radiologist who was aware of final diagnosis reviewed CT scans and recorded qualitative features of affected and normal incisors. Mean density values for the pulp cavity and palatal and buccal dentin were also recorded. A total of 16 prairie dogs were sampled (12 normal maxillary incisors, 20 confirmed maxillary incisor pseudo‐odontomas, 20 normal mandibular incisors, 12 presumed mandibular incisor pseudo‐odontomas). Maxillary incisors with confirmed pseudo‐odontomas had a significantly hyperattenuating pulp and dentin in the reserve crown and apical zone, when compared to normal maxillary incisors. Pseudo‐odontomas appeared as enlargements of the apical zone with a globular/multilobular hyperattenuating mass formation haphazardly arranged, encroaching on midline and growing caudally and ventrally. Presumed mandibular incisor pseudo‐odontomas had similar CT characteristics. In 60% of prairie dogs with maxillary incisor pseudo‐odontomas, the hard palate was deformed and the mass bulged into the oral cavity causing loss of the palatine bone. The common nasal meatus was partially or totally obliterated in 81.8% of prairie dogs with maxillary pseudo‐odontomas. Findings supported the use of CT for characterizing extent of involvement and surgical planning in prairie dogs with pseudo‐odontomas.     

Batch Chromium(VI), Cadmium(II) and Lead(II) Removal from Aqueous Solutions by Horticultural Peat

The selectivity and uptake capacity of horticultural peat available in Romania was evaluated with respect to the removal of Cd(II), Cr(VI) and Pb(II) ions from aqueous solution. The kinetics, sorption capacities, selectivity and pH dependence of sorption were determined. The influence of metal concentration in solution is discussed in the terms of Langmuir and Freundlich isotherm and constants. Sorption capacities increased with increasing metal concentration in solution. For solutions containing 300 mg/l of metal, the observed uptake capacities were 20 mg Cd(II)/g peat, 15 mg Cr(VI)/g peat and 30 mg Pb(II)/g peat. The study proved that horticultural peat is a suitable material for the removal of the studied heavy metal ions from aqueous solutions, achieving removal efficiencies higher than 90%, and could be considered as a potential material for treating effluent polluted with Cd(II), Cr(VI) and Pb(II) ions.     

Transmission and control implications of seroconversion to Maedi-Visna virus in Basque dairy-sheep flocks

A retrospective analysis of seroconversion to Maedi-Visna virus (MVV) was carried out for 10 infected semi-intensively reared dairy-sheep flocks that were tested annually between 1994 and 1999. Four of the flocks raised replacement lambs artificially with bovine colostrum and milk replacement to avoid lactogenic MVV infection but did not prevent aerosol contact between replacements and other sheep in the flock. Flock culling percentages ranged between 14 and 25% and in eight flocks the number of sheep that seroconverted was similar to or lower than the number of sheep culled—suggesting that incidence could be reduced by culling seropositive sheep without increasing average culling percentages. Random-effects logistic regression indicated that seroconversion was associated positively with increasing contact with infected sheep and with lifetime MV-serological status of the dam (used as a proxy measure of genetic susceptibility), but not with mode of rearing pre-weaning (artificially or with a seropositive or seronegative dam). Our results indicate that when conditions allow efficient horizontal transmission, there is no evidence that lactogenic infection increases the risk of MV infection and that there is an important inheritable component of disease resistance or susceptibility.     

Seroprevalence and associated risk factors of neosporosis in beef and dairy cattle in Italy

A cross-sectional serological survey for Neospora caninum was carried out on beef and dairy cattle in southern and northern Italy. A total of 111 herds and 1140 animals were tested using an ELISA assay (CHEKIT-Neospora) to detect anti-N. caninum antibodies. Management and individual data were collected and analysed both by linear and logistic multiple-regression models in order to find good predictors of the cattle seroprevalence and anti-N. caninum antibody level. At least one seropositive animal was found in 49 herds (44.1%), of which 31 (39.7%) from southern Italy and 18 (54.5%) from northern Italy. A total of 126 head of cattle (11%) were found to be seropositive and the seroprevalence was lower in southern (8.7%) than in northern Italy (16%). One of the best predictors of neosporosis seroprevalence in this study was the practice of self-rearing replacement heifers. Further risk factors were linked to higher stocking density, i.e. animals farmed in large herds and with no summer or permanent grazing practices were more likely to be seropositive than others. Farms with two or more dogs had higher herd seropositivity than farms with one or no dogs and this factor interacted significantly with the farm size and presence of poultry. Among individual characteristics, seropositivity was higher in animals sampled in mid- or late-pregnancy compared to animals either in early pregnancy or not pregnant. There was a significant interaction between the factors for pregnancy status and grazing practices. None of the epidemiological data recorded was a good predictor of the anti-N. caninum antibody level.     

HPLC determination of fenoxaprop and fenoxaprop-ethyl in different soils

This paper describes a method for the determination of fenoxaprop ethyl and fenoxaprop residues in four soil types using two extraction procedures: extraction with 0.1 M hydrochloric acid/methanol, partitioning with dichloromethane and extraction with ethyl acetate. The extracts were purified on florisil or alumina cartridge. The analyses were performed by reverse phase HPLC with UV detection at 280 nm. The best results in terms of recovery, clean-up efficiency and independence of soil characteristics were obtained with the combination ethyl acetate extraction alumina clean-up. Under these conditions, the recoveries were higher than 70 % and the detection limit was 0.02 mg kg^?1 soil.     

Micropropagation of the Brazilian endemic bromeliad Vriesea reitzii trough nodule clusters culture

Vriesea reitzii Leme & Costa is an endemic bromeliad from the Atlantic Forest in South Brazil. The devastation of this biome threatens the extinction of this species that besides its role in the ecosystem has an ornamental value. Tissue culture techniques are important tools for the mass propagation of threatened bromeliad species. In the present work we established an in vitro regenerative protocol for the large-scale propagation, and improvement of this species. Young basal leaves used as explants showed 90.6% induction rate of nodule clusters in MS culture medium supplemented with 20.0 μM 2,4-D and 1.0 μM Kin. The subculture of these nodule clusters to MS medium with BAP, Kin and 2-iP resulted in a regeneration rate of 60 shoots/g nodule clusters. Subsequent subculture to MS media supplemented with 2.5 μM 2-iP and 0.5 μM NAA and then to MS medium free of PGR enhanced the full development of plantlets. Plantlets longer than 3 cm were successfully acclimatized showing a survival rate of 90%.     

Brassinosteroid analogue effects on the yield of yellow passion fruit plants (Passiflora edulis f. flavicarpa)

The effects of successive brassinosteroid analogue (BR) applications (0.1 mg l⁻¹ of brassinosteroid analogue BB-16) were evaluated on commercial yellow passion fruit (Passiflora edulis f. flavicarpa) orchards in the first year of production. The treatments applied were: control, BR-1 (1 BR application shortly after the first flowers appeared), BR-2, BR-3, BR-4 and BR-5 (BR application in two, three, four and five consecutive weeks after the appearance of the first flowers, respectively). The fruits were collected for seven consecutive weeks (105 fruits treatment⁻¹) and fruit mass, length and diameter, soluble solid contents; pulp mass and peel thickness were evaluated in the laboratory. Multivariate analysis was performed in order to determine whether there were differences among the treatments taking into account all the measurements made. BR-3 was the most promising treatment because it produced the highest number of fruits plant⁻¹ (81.5) compared to the control (53.5) and the soluble solid content was 1 °Brix greater than the control. The BR-3 treatment resulted in a 65% increase in the estimated yield of the passion fruit plants, corresponding to 20 t ha⁻¹ compared to the control yield of 12 t ha⁻¹. The results showed that BB-16 sprayed during a period of reproductive development can increase the number of fruits per plant.     

Natural cases of polyarthritis associated with feline calicivirus infection in cats

Veterinary Research Communications - The limping syndrome is occasionally reported during acute feline calicivirus (FCV) infections or as consequence of vaccination. In this retrospective study,...