664 research outputs found
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
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
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
Heat shock proteins and regulatory T cells
Heat shock proteins (HSPs) are important molecules required for ideal protein function. Extensive research on the functional properties of HSPs indicates that HSPs may be implicated in a wide range of physiological functions including immune function. In the immune system, HSPs are involved in cell proliferation, differentiation, cytokine release, and apoptosis. Therefore, the ability of the immune system, in particular immune cells, to function optimally and in unison with other physiological systems is in part dependent on signaling transduction processes, including bidirectional communication with HSPs. Regulatory T cells (Tregs) are important T cells with suppressive functions and impairments in their function have been associated with a number of autoimmune disorders. The purpose of this paper is to examine the relationship between HSPs and Tregs. The interrelationship between cells and proteins may be important in cellular functions necessary for cell survival and expansion during diseased state
PomBase 2015: updates to the fission yeast database.
PomBase (http://www.pombase.org) is the model organism database for the fission yeast Schizosaccharomyces pombe. PomBase provides a central hub for the fission yeast community, supporting both exploratory and hypothesis-driven research. It provides users easy access to data ranging from the sequence level, to molecular and phenotypic annotations, through to the display of genome-wide high-throughput studies. Recent improvements to the site extend annotation specificity, improve usability and allow for monthly data updates. Both in-house curators and community researchers provide manually curated data to PomBase. The genome browser provides access to published high-throughput data sets and the genomes of three additional Schizosaccharomyces species (Schizosaccharomyces cryophilus, Schizosaccharomyces japonicus and Schizosaccharomyces octosporus)
The Wicked Machinery of Government: Malta and the Problems of Continuity under the New Model Administration
This is a study focused on the early years of British rule in Malta (1800-1813). It explores the application to the island of the “new model” of colonial government, one based on direct rule from London mediated by the continuation of existing laws and institutions. Systemic deficiencies are identified. These tended to undermine the effectiveness of direct British rule. This study also reveals, in the context of legal and constitutional continuity, unresolved tensions between modernity and tradition. The political stability of the island was damaged and the possibility of continued British possession was threatened
Modulational instability in a silicon-on-insulator directional coupler: Role of the coupling-induced group velocity dispersion
We report frequency conversion experiments in silicon-on-insulator (SOI) directional couplers. We demonstrate that the evanescent coupling between two subwavelength SOI waveguides is strongly dispersive and significantly modifies modulational instability (MI) spectra through the coupling induced group velocity dispersion (GVD). As the separation between two 380-nm-wide silicon photonic wires decreases, the increasing dispersion of the coupling makes the GVD in the symmetric supermode more normal and suppresses the bandwidth of the MI gain observed for larger separations
PomBase: a comprehensive online resource for fission yeast.
PomBase (www.pombase.org) is a new model organism database established to provide access to comprehensive, accurate, and up-to-date molecular data and biological information for the fission yeast Schizosaccharomyces pombe to effectively support both exploratory and hypothesis-driven research. PomBase encompasses annotation of genomic sequence and features, comprehensive manual literature curation and genome-wide data sets, and supports sophisticated user-defined queries. The implementation of PomBase integrates a Chado relational database that houses manually curated data with Ensembl software that supports sequence-based annotation and web access. PomBase will provide user-friendly tools to promote curation by experts within the fission yeast community. This will make a key contribution to shaping its content and ensuring its comprehensiveness and long-term relevance
Ensembl Genomes 2013: scaling up access to genome-wide data
Ensembl Genomes (http://www.ensemblgenomes.org) is an integrating resource for genome-scale data from non-vertebrate species. The project exploits and extends technologies for genome annotation, analysis and dissemination, developed in the context of the vertebrate-focused Ensembl project, and provides a complementary set of resources for non-vertebrate species through a consistent set of programmatic and interactive interfaces. These provide access to data including reference sequence, gene models, transcriptional data, polymorphisms and comparative analysis. This article provides an update to the previous publications about the resource, with a focus on recent developments. These include the addition of important new genomes (and related data sets) including crop plants, vectors of human disease and eukaryotic pathogens. In addition, the resource has scaled up its representation of bacterial genomes, and now includes the genomes of over 9000 bacteria. Specific extensions to the web and programmatic interfaces have been developed to support users in navigating these large data sets. Looking forward, analytic tools to allow targeted selection of data for visualization and download are likely to become increasingly important in future as the number of available genomes increases within all domains of life, and some of the challenges faced in representing bacterial data are likely to become commonplace for eukaryotes in future
Postulated Vasoactive Neuropeptide Autoimmunity in Fatigue-Related Conditions: A Brief Review and Hypothesis
Disorders such as chronic fatigue syndrome (CFS) and gulf war syndrome (GWS) are characterised by prolonged fatigue and a range of debilitating symptoms of pain, intellectual and emotional impairment, chemical sensitivities and immunological dysfunction. Sudden infant death syndrome (SIDS) surprisingly may have certain features in common with these conditions. Post-infection sequelae may be possible contributing factors although ongoing infection is unproven. Immunological aberration may prove to be associated with certain vasoactive neuropeptides (VN) in the context of molecular mimicry, inappropriate immunological memory and autoimmunity
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