Development of in-house ELISA for detection of chloramphenicol in bovine milk with subsequent confirmatory analysis by LC-MS/MS

This study was undertaken to develop and validate direct competitive ELISA for the determination of chloramphenicol residues in bovine milk. Antisera and an enzyme-tracer for chloramphenicol were prepared and used to develop an ELISA with inhibition concentrations, IC₂₀ and IC₅₀, of 0.09 and 0.44 ng mL^?1, respectively. Milk samples were spiked with standards equivalent to 0, 0.2, 0.3, 0.5, 1.0 &; 1.5 ng mL^?1 and extracted in methanol. The mean recoveries were found to be 73–100% with coefficient of variance 7–11%. The decision limit (CCα) and detection capability (CCβ) were calculated as 0.10 and 0.12 ng mL^?1, respectively. The results were found comparable with the commercial ELISA, having recoveries of 87 to 100%, CCα 0.09 ng mL^?1 and CCβ 0.12 ng mL^?1. As per Commission Decision 2002/657/EC, in-house ELISA was further validated by using LC-MS/MS. Mass spectral acquisition was done by using electrospray ionization in the negative ion mode applying single reaction monitoring of the diagnostic transition reaction for CAP (m/z 152, 194 and 257). The calibration curve showed good linearity in concentrations from 0.025 to 1.6 ng mL^?1 with correction coefficient 0.9902. The mean recoveries were found to be 88 to 100%. The CCα was calculated as 0.057 ng mL^?1 and CCβ 0.10 ng mL^?1. Since CCα and CCβ are less than half of the MRPL (0.15 ng mL^?1), the test was found suitable for screening and quantification of CAP residues in bovine milk samples. Results of surveillance studies indicated that out of 31 analyzed milk samples, 12.9% samples were found with CAP residues but only 3.2% samples were declared positive with maximum concentration 0.31 ng mL^?1, slightly above the MRPL.     

Energy implications of the thermal recovery of biodegradable municipal waste materials in the United Kingdom

Waste management policies and legislation in many developed countries call for a reduction in the quantity of biodegradable waste landfilled. Anaerobic digestion, combustion and gasification are options for managing biodegradable waste while generating renewable energy. However, very little research has been carried to establish the overall energy balance of the collection, preparation and energy recovery processes for different types of wastes. Without this information, it is impossible to determine the optimum method for managing a particular waste to recover renewable energy. In this study, energy balances were carried out for the thermal processing of food waste, garden waste, wood, waste paper and the non-recyclable fraction of municipal waste. For all of these wastes, combustion in dedicated facilities or incineration with the municipal waste stream was the most energy-advantageous option. However, we identified a lack of reliable information on the energy consumed in collecting individual wastes and preparing the wastes for thermal processing. There was also little reliable information on the performance and efficiency of anaerobic digestion and gasification facilities for waste.     

Oversight of shale gas production in the United States and the disclosure of toxic substances

With the encouragement of shale gas production in the United States, governments have considered a range of legislative and regulatory proposals to manage health and environmental damages that may accompany extraction activities. Exceptions adopted by Congress to major federal environmental legislation have meant that individual US states have deemed it necessary to provide oversight through regulations to protect people and safeguard environmental quality. In responding, states have legal structures under which drilling firms may not need to disclose the toxic substances used in fracturing wells. Yet, with increasing numbers of drilling sites, more people are at risk from accidents and exposure to harmful substances used at fractured wells. To provide for meaningful health and safety protection, governments may need to reevaluate legal provisions offering trade secret protection for toxic substances used in fracturing.     

Quantification of gasoline-ethanol blend emissions effects

ABSTRACT

Emissions levels from current gasoline spark-ignited engines are low, and emissions changes associated with the blending of ethanol into gasoline are small and difficult to quantify. Addition of ethanol, with a high blending octane number, allows a reduction in aromatics in market gasoline. Blending behavior of ethanol is nonlinear, altering the distillation curve, including the 50% temperature point, T50. Increase in gasoline direct injection (GDI) engine technology in the fleet challenges ability of older models based on port fuel injection (PFI) results to predict the overall air quality impact of ethanol blending. Five different models derived from data collected through U.S. Environmental Protection Agency Energy Policy Act (EPAct) programs were used to predict LA92 Phase 1 particulate matter (PM) emissions for summer regular (SR) E0 (gasoline with 0% ethanol by volume), E10 (gasoline with 10% ethanol) and E15 (gasoline with 15% ethanol). Substantial reductions of PM for E10 and E15 relative to E0 were predicted when aromatics were displaced by ethanol to maintain octane rating. SR E0 and E10 were also matched to linear combinations of EPAct fuels and results showed a 35% PM reduction for SR E10 relative to SR E0. For GDI vehicles the Coordinating Research Council (CRC) E-94-3 study found that E10 had 23% or 29% PM increase. However, CRC E-129 found an E10 PM reduction of 10% when one E0 fuel and its splash blended (SB) E10 were compared. Both CRC project E-129 SB data and fuel triplets selected from the EPAct study showed variation for E15 emissions, although E-129 suggests that E15 in GDI offers about a 25% reduction of PM with respect to E0. Overall, data suggest that ethanol blending offers a modest to a substantial reduction of cold-start PM mass if aromatic levels of the finished products are reduced in response to ethanol addition.

Implications: Studies of exhaust emissions effects of ethanol blending with gasoline vary in conclusions. Blending properties are nonlinear. Modeling of real-world emissions effects must consider all fuel composition adjustments and property changes associated with ethanol addition. Aromatics are reduced in E10 or E15, compared with E0, and distillation changes. PFI-derived models show reductions in cold-start PM for expected average E10 versus E0 pump fuel, due to reduced aromatic content. Relative emissions effects from older technology (PFI) engines do not predict newer engine (GDI) results reliably, but recent GDI data show reduced cold-start PM when ethanol displaces aromatics.     

Alternatives for private participation in the provision of water services

Recent years have seen a region-wide movement throughout Latin America and the Caribbean toward wider private participation in the provision of infrastructure, as well as in other public services. This paper discusses the possible benefits from the privatization of water services and illustrates the range of alternatives available for private participation in their provision. These alternatives are analyzed and their possible application in Latin America and the Caribbean is assessed on the basis of examples from the region and other parts of the world. However, the paper does not discuss, in any detail, the theoretical justifications for the movement back to a market system in the provision of public services.     

Limitations on the Confinement of Food Animals in the United States

Citizen petitions and legislative bills in seven states in the US have established space and movement limitations for selected species of farm animals. These actions show Americans becoming concerned about the humane treatment of confined farm animals, and willing to use governmental intervention to preclude existing confinement practices. The individual state provisions vary, including the coverage of species. All seven states deal with sow-gestation crates, five states address veal calf crates, and two states’ provisions also apply to battery cages used for egg-laying hens. The actions show citizen and legislative opposition to current animal production practices, and suggest a movement to provide better treatment for farm animals. Accompanying the actions are challenges for animal production industries in remaining competitive while meeting social expectations on the ethical treatment of food animals. While the actions are only a small step in addressing welfare issues, they may be the beginning of a significant movement to do more to address human and animal welfare issues.     

New regulations to minimize water impairment from animals rely on management practices

Water pollution from concentrated animal feeding operations (CAFOs) led to revised federal regulations in the United States. The regulations provide for the greater management of potential sources of agricultural contamination and impose additional financial costs on producers. Along with a duty to secure a permit, significant changes address coverage of pollutants, separation of production and land application areas, effluent limitation guidelines, and differentiating agricultural storm water discharges from other discharges. The revised provisions require more producers to secure National Pollutant Discharge Elimination System permits and mandate that large CAFOs develop technology-based effluent discharge limitations involving best management practices. Medium- and small-sized CAFOs need to adopt technology-based effluent discharge requirements employing best professional judgment. For farms raising animals that are not CAFOs, voluntary management practices may be employed to intercept pollutants before they enter waterbodies. Additional educational efforts promoting the implementation of further management practices that address the agricultural impairment of water resources may be needed.     

Tree Structure and Diversity in Human-Impacted Littoral Forests, Madagascar

This research surveyed human-impacted littoral forests in southeastern Madagascar to determine (i) how forest structural features, indicative of human impact, are related to total, utilitarian, and endemic tree diversity; (ii) the distribution, abundance, and demographics of tree species groups (i.e., total, useful, endemic) across the landscape; and (iii) the amount of basal area available per human use category. We also use these data to consider issues of sustainable use and how human impact may influence littoral forest tree community composition across the landscape. Within 22 transects of 400 m² each, we recorded a total of 135 tree species and 2155 individuals. Seventy-nine species (58%) were utilitarian and 56 (42%) were nonutilitarian species. Of the 2155 individuals, 1827 (84%) trees were utilitarian species. We recorded 23 endemic species (17% of the total species) and 17 (74%) of these were utilitarian species. Basal area was significantly correlated with Shannon Weiner Index values for total (r = 0.64, P < 0.01), utilitarian (r = 0.58, P < 0.01), and endemic tree diversity (r = 0.85, P < 0.01). Basal area was significantly correlated with the Simpson’s index values for the endemic species (r = 0.74, P < 0.01). These correlations suggest that endemic tree species, of high global conservation value, may be the species group most influenced by changes in forest structure. Utilitarian species constituted 84% of the total basal area. The use category contributing the highest amount of basal area to the landscape was firewood. The results presented herein demonstrate that the landscape of southeastern Madagascar, commonly perceived as degraded, retains high value for both global conservation purposes and for local livelihoods. Thus, valuable opportunities may exist for developing conservation incentives that leverage both global and local conservation needs.     

Within-tree life process models of the southern pine beetle, dendroctonus frontalis

This paper develops models of gallery construction, emergence and re-emergence for use in a general population dynamics model of the southern pine beetle, Dendroctonuc frontalis Zimmermann. Models of these processes were originally developed from laboratory data, and are extended here to account for fluctuating temperatures and variable attack densities under field conditions. The resulting models were tested using data from three natural populations (infestations) from east Texas. These tests reveal that the laboratory-derived models closely predict the timing and length of gallery, and the timing of emergence and re-emergence in the field.