Public health and landfill sites

Landfill management is a complex discipline, requiring very high levels of organisation, and considerable investment. Until the early 1990’s most Irish landfill sites were not managed to modern standards. Illegal landfill sites are, of course, usually not managed at all. Landfills are very active. The traditional idea of ‘put it in the ground and forget about it’ is entirely misleading. There is a lot of chemical and biological activity underground. This produces complex changes in the chemistry of the landfill, and of the emissions from the site. The main emissions of concern are landfill gases and contaminated water (which is known as leachate). Both of these emissions have complex and changing chemical compositions, and both depend critically on what has been put into the landfill. The gases spread mainly through the atmosphere, but also through the soil, while the leachate (the water) spreads through surface waters and the local groundwater. Essentially all unmanaged landfills will discharge large volumes of leachate into the local groundwater. In sites where the waste accepted has been properly regulated, and where no hazardous wastes are present, there is a lot known about the likely composition of this leachate and there is some knowledge of its likely biological and health effects. This is not the case for poorly regulated sites, where the composition of the waste accepted is unknown. It is possible to monitor the emissions from landfills, and to reduce some of the adverse health and environmental effects of these. These emissions, and hence the possible health effects, depend greatly on the content of the landfill, and on the details of the local geology and landscape. There is insufficient evidence to demonstrate a clear link between cancers and exposure to landfill, however, it is noted that there may be an association with adverse birth outcomes such as low birth weight and birth defects. It should be noted, however, that modern landfills, run in strict accordance with standard operation procedures, would have much less impact on the health of residents living in proximity to the site

Review of Victoria Kahn, Neil Saccamano, and Daniela Coli, eds. Politics and the Passions, 1500-1850.

Victoria Kahn, Neil Saccamano, and Daniela Coli, eds. Politics and the Passions, 1500-1850. Princeton and Oxford: Princeton University Press, 2006. vi + 314 pp. ISBN 0691118620 (paper)

Advanced Fenton processing of aqueous phenol solutions:a continuous system study including sonication effects

Our previous report based on a batch reactor system for the Advanced Fenton Process (AFP) showed that pH, hydrogen peroxide and the organic substances treated are among the most important factors affecting the oxidation efficiency. As an extended study towards its commercialisation, this paper reports the effects of the main process parameters including those relating to a new AFP flow-through system. In order to systemise and correlate the results, the Taguchi experimental design method was used. Total organic carbon (TOC) removal was utilised as the measure of the oxidation efficiency and it was found that the removal of phenol from aqueous solution at pH 2.0 and 2.5 was very similar but hydrogen peroxide supply significantly affected the TOC removal with the change of flow rate from 14.4 mL/hr to 60 mL/hr. Also, the initial concentration of phenol was a highly significant factor, with higher concentrations resulting in a lower TOC removal rate. The temperature effects in the range of 14 °C to 42 °C were investigated and it was found that there was accelerated oxidation of phenol in the early stages but after 90 minutes there was no significant difference between the results. Sonication with a bath type sonicator resulted in relatively small enhancements of TOC removal but further studies with cup-horn and probe type sonicators showed that TOC removal increased with higher intensity of sonication on additional input of hydrogen peroxide

GrameneMart: the BioMart data portal for the Gramene project

Gramene is a well-established resource for plant comparative genome analysis. Data are generated through automated and curated analyses and made available through web interfaces such as GrameneMart. The Gramene project was an early adopter of the BioMart software, which remains an integral and well-used component of the Gramene website. BioMart accessible data sets include plant gene annotations, plant variation catalogues, genetic markers, physical mapping entities, public DNA/mRNA sequences of various types and curated quantitative trait loci for various species. Database URL: http://www.gramene.org/biomart/martview

Comparison between PI and PR Current Controllers in Grid Connected PV Inverters

This paper presents a comparison between Proportional Integral (PI) and Proportional Resonant (PR) current controllers used in Grid Connected Photovoltaic (PV) Inverters. Both simulation and experimental results will be presented. A 3kW Grid-Connected PV Inverter was designed and constructed for this research

Postulated Role of Vasoactive Neuropeptide-Related Immunopathology of the Blood Brain Barrier and Virchow-Robin Spaces in the Aetiology of Neurological-Related Conditions

Vasoactive neuropeptides (VNs) such as pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) have critical roles as neurotransmitters, vasodilators including perfusion and hypoxia regulators, as well as immune and nociception modulators. They have key roles in blood vessels in the central nervous system (CNS) including maintaining functional integrity of the blood brain barrier (BBB) and blood spinal barrier (BSB). VNs are potent activators of adenylate cyclase and thus also have a key role in cyclic AMP production affecting regulatory T cell and other immune functions. Virchow-Robin spaces (VRSs) are perivascular compartments surrounding small vessels within the CNS and contain VNs. Autoimmunity of VNs or VN receptors may affect BBB and VRS function and, therefore, may contribute to the aetiology of neurological-related conditions including multiple sclerosis, Parkinson's disease, and amyotrophic lateral sclerosis. VN autoimmunity will likely affect CNS and immunological homeostasis. Various pharmacological and immunological treatments including phosphodiesterase inhibitors and plasmapheresis may be indicated

Exfiltration from sewers - is it a serious problem?

This paper contends that estimates of exfiltration leakage from sewers, and the problems arising from it may be too high due to an underestimation of the “self-repairing” action of sewage and sewage sediments in raw sewage. Two aspects of a continuing programme of research are reported;(i) the measurement of exfiltration rates from a range of defects in a sewer pipe with pipe bedding effects simulated by a dry gravel trench surround to the pipe, and (ii) an assessment of the persistence of pathogens in the gravel and soil beneath the test rig pipe, using coliforms as a biological indicator. The results show that the introduction of a gravel surround resulted in more rapid and effective sealing across the entire range of defects tested compared to previously performed experiments with the defects discharging to air. Complete sealing eventually occurred on every run for a 10 mm x 10 mm defect situated at the invert of the sewer and the lowest recorded levels in each experiment for a 10 mm wide radial defect were of the order 10-3 to 10-4 ls-1. These results have been scaled-up to estimate leakage rates in lengths of sewers and sub-catchments and levels significantly lower than previously estimated are indicated. Additionally, the pilot experiment to investigate the fate of biological contaminants in the exfiltrate suggests rapid reduction in microorganisms levels beneath the sewer pipe

The Plasmodium berghei Ca(2+)/H(+) exchanger, PbCAX, is essential for tolerance to environmental Ca(2+) during sexual development.

Ca(2+) contributes to a myriad of important cellular processes in all organisms, including the apicomplexans, Plasmodium and Toxoplasma. Due to its varied and essential roles, free Ca(2+) is tightly regulated by complex mechanisms. These mechanisms are therefore of interest as putative drug targets. One pathway in Ca(2+) homeostatic control in apicomplexans uses a Ca(2+)/H(+) exchanger (a member of the cation exchanger family, CAX). The P. falciparum CAX (PfCAX) has recently been characterised in asexual blood stage parasites. To determine the physiological importance of apicomplexan CAXs, tagging and knock-out strategies were undertaken in the genetically tractable T. gondii and P. berghei parasites. In addition, a yeast heterologous expression system was used to study the function of apicomplexan CAXs. Tagging of T. gondii and P. berghei CAXs (TgCAX and PbCAX) under control of their endogenous promoters could not demonstrate measureable expression of either CAX in tachyzoites and asexual blood stages, respectively. These results were consistent with the ability of parasites to tolerate knock-outs of the genes for TgCAX and PbCAX at these developmental stages. In contrast, PbCAX expression was detectable during sexual stages of development in female gametocytes/gametes, zygotes and ookinetes, where it was dispersed in membranous networks within the cytosol (with minimal mitochondrial localisation). Furthermore, genetically disrupted parasites failed to develop further from "round" form zygotes, suggesting that PbCAX is essential for ookinete development and differentiation. This impeded phenotype could be rescued by removal of extracellular Ca(2+). Therefore, PbCAX provides a mechanism for free living parasites to multiply within the ionic microenvironment of the mosquito midgut. Ca(2+) homeostasis mediated by PbCAX is critical and suggests plasmodial CAXs may be targeted in approaches designed to block parasite transmission