Monoclonal antibody produced by heterologous indirect enzyme-linked immunosorbent assay and its application for parathion residue determination in agricultural and environmental samples

A heterologous indirect enzyme-linked immunosorbent assay (ELISA) was developed, which was based on monoclonal antibody (Mab) to determine parathion residue in agricultural and environmental samples. Eight Mabs were produced by introducing the heterologous indirect ELISA into the screening procedure. It was shown that these Mabs had more broad-reactivity with twenty competitors than that of 5H7 (Mab produced by homologous screening). So it became much easier using these new Mabs to develop heterologous immunoassays. In addition, all the developed heterologous ELISAs could be used to determine parathion residue in semiquantitative or quantitative level, and their detection limitation (LOD) was around 2 ng/mL. Compared with the previous heterologous ELISA (hapten 11/5H7) with IC₅₀ of 13.3 ng/mL, a better heterologous ELISA (hapten 11/1E1) was obtained with IC₅₀ of 3.8 ng/mL, which improved the sensitivity 3.5 times. Finally, the latter was applied to parathion residue determination in spiked agricultural and environmental samples without extraction or cleanup. The average recoveries of parathion added to water, soil, cucumber, Chinese cabbage and carrot were between 80.4 % and 111.8 %. The LOD for water and soil samples was 5 ng/mL, and the LOD for cucumber, rice and corn samples was 10 ng/mL.     

Challenges in non-invasive prenatal screening for sub-chromosomal copy number variations using cell-free DNA

Non-invasive prenatal screening (NIPS) has revolutionized the approach to prenatal fetal aneuploidy screening. Many commercial providers now offer analyses for sub-chromosomal copy number variations (CNVs). Here, we review the use of NIPS in the context of screening for microdeletions and microduplications, issues surrounding the choice of disorders tested for, and the advantages and disadvantages associated with the inclusion of microdeletions to current NIPS. Several studies have claimed benefits; however, we suggest that microdeletions have not demonstrated a low enough false positive rate to be deemed practical or ethically acceptable, especially considering their low positive predictive values. Because a positive NIPS result should be confirmed using diagnostic techniques, and false positive rates are as high as 90% for some microdeletions, diagnostic testing seems preferable when the goal is to maximize the detection of microdeletion or microduplication syndromes.     

Chemical,physical and microbial properties and microbial diversity in manufactured soils produced from co-composting green waste and biosolids

The effects of adding biosolids to a green waste feedstock (100% green waste, 25% v/v biosolids or 50% biosolids) on the properties of composted products were investigated. Following initial composting, 20% soil or 20% fly ash/river sand mix was added to the composts as would be carried out commercially to produce manufactured soil. Temperatures during composting reached 50 °C, or above, for 23 days when biosolids were included as a composting feedstock but temperatures barely reached 40 °C when green waste alone was composted. Addition of biosolids to the feedstock increased total N, EC, extractable NH₄, NO₃ and P but lowered pH, macroporosity, water holding capacity, microbial biomass C and basal respiration in composts. Additions of soil or ash/sand to the composts greatly increased the available water holding capacity of the materials. Principal component analysis (PCA) of PCR-DGGE 16S rDNA amplicons separated bacterial communities according to addition of soil to the compost. For fungal ITS-RNA amplicons, PCA separated communities based on the addition of biosolids. Bacterial species richness and Shannon’s diversity index were greatest for composts where soil had been added but for fungal communities these parameters were greatest in the treatments where 50% biosolids had been included. These results were interpreted in relation to soil having an inoculation effect and biosolids having an acidifying effect thereby favouring a fungal community.     

Sulfur Concentrations in Plant Foliage and Related Effects

Sulfur Is an essential element for plants and is normally taken up from soil In the sulfate form. S0₂ absorbed from the air also can supply S for plant nutrition. Plants are therefore dependent on an optimum S content, but deficiencies or excesses can result in deleterious effects. The Phytotoxicology Section has conducted numerous assessment surveys in rural, urban, or industrial locations in Ontario to determine the concentrations of S in plants and related effects. During the ten year period, 1968 to 1977, about 50,000 samples of vegetation and soil were collected and analyzed for S concentrations. The results of these analyses were examined with respect to natural background concentrations of S in foliage of 33 different species, and effects observed on plant life associated with excess concentrations of S. For example, in one situation 0.35% sulfur in foliage of trembling aspen trees was found to be the threshold level for injury to occur. Some of the industries surveyed for the degree and extent of S effects in their vicinity included pulp mills, power plants, iron concentrators, and gold, nickel, and copper smelters. In interpreting the results of S analyses in plant foliage for diagnostic purposes, consideration should be given also to the geographical location, the stage of growth of the plant, the relation of visible injuries to pollutant or biological causes, the S content of the soil, and S0₂ emission data for the area.     

Climate change mitigation policy paradigms—national objectives and alignments

The aim of this paper is to assess how policy goals in relation to the promotion of green growth, energy security, pollution control and greenhouse gas (GHG) emissions reductions have been aligned in policies that have been implemented in selected countries during the last decades as a basis for discussing how a multi objective policy paradigm can contribute to future climate change mitigation. The paper includes country case studies from Brazil, Canada, China, the European Union (EU), India, Japan, Mexico, Nigeria, South Africa, South Korea and the United States covering renewable energy options, industry, transportation, the residential sector and cross-sectoral policies. These countries and regions together contribute more than two thirds of global GHG emissions. The paper finds that policies that are nationally driven and that have multiple objectives, including climate-change mitigation, have been widely applied for decades in both developing countries and industrialised countries. Many of these policies have a long history, and adjustments have taken place based on experience and cost effectiveness concerns. Various energy and climate-change policy goals have worked together in these countries, and in practice a mix of policies reflecting specific priorities and contexts have been pursued. In this way, climate-change mitigation has been aligned with other policy objectives and integrated into broader policy packages, though in many cases specific attention has not been given to the achievement of large GHG emission reductions. Based on these experiences with policy implementation, the paper highlights a number of key coordination and design issues that are pertinent to the successful joint implementation of several energy and climate-change policy goals.     

Comparison of gas chromatography and immunoassay methods in measuring the distribution of dieldrin in rainbow trout tissues.

Studies have been conducted to determine the distribution of dieldrin in various tissues of rainbow trout when exposed to several dieldrin concentrations. Medium sized fish with an average weight and length of 195.4 +/- 30.5 g and 25.7 +/- 1.4 cm, respectively, were placed in groups of 6 in 300 L tanks containing purified and aerated water and maintained at 10 degrees C. Following an acclimatization period of 10 days, each group of fish was exposed to one of four dieldrin concentrations ranging from 50 to 80 ppb. After 24 hours, the fish were taken out of the tanks and sacrificed. The brain, gills, liver, muscles and skin were collected from each fish. Dieldrin was extracted from each tissue using SPE techniques and analyzed by both gas chromatography (GC) and enzyme linked immunosorbent assay (ELISA). Results of analyses by the two techniques were highly correlated. The results also showed that liver and skin tissues had the highest level of dieldrin residues. In comparing the means of the six fish samples, it was found that liver or skin contained about 1.5-fold the level in brain, about 4.0 fold the level in muscles and about 6.5 fold the level in gills. Immunoassay proved to be as reliable an analytical tool as gas chromatography in this case.