32 research outputs found
Selection of an internet content filtering solution using the analytic hierarchy process
This talk describes the selection of an Internet Content Filtering solution suitable for the specific requirements of the Waikato Institute of Technology (Wintec). Product data was collected from a variety of sources including: vendor product datasheets, industry benchmark tests, the experiences of other institutions and the academic literature. The available solutions were compared using the Analytic Hierarchy Process (Saaty 1980), a multicriteria decision support tool, using the above data and priority weightings determined for each criterion
Comprehensive Audiometric Analysis of Hearing Impairment and Tinnitus After Cisplatin-Based Chemotherapy in Survivors of Adult-Onset Cancer.
PURPOSE:
Cisplatin is widely used but highly ototoxic. Effects of cumulative cisplatin dose on hearing loss have not been comprehensively evaluated in survivors of adult-onset cancer. PATIENTS AND METHODS:
Comprehensive audiological measures were conducted on 488 North American male germ cell tumor (GCT) survivors in relation to cumulative cisplatin dose, including audiograms (0.25 to 12 kHz), tests of middle ear function, and tinnitus. American Speech-Language-Hearing Association criteria defined hearing loss severity. The geometric mean of hearing thresholds (0.25 to 12 kHz) summarized overall hearing status consistent with audiometric guidelines. Patients were sorted into quartiles of hearing thresholds of age- and sex-matched controls. RESULTS:
Increasing cumulative cisplatin dose (median, 400 mg/m(2); range, 200 to 800 mg/m(2)) was significantly related to hearing loss at 4, 6, 8, 10, and 12 kHz (P trends, .021 to \u3c .001): every 100 mg/m(2) increase resulted in a 3.2-dB impairment in age-adjusted overall hearing threshold (4 to 12 kHz; P \u3c .001). Cumulative cisplatin doses \u3e 300 mg/m(2) were associated with greater American Speech-Language-Hearing Association-defined hearing loss severity (odds ratio, 1.59; P = .0066) and worse normative-matched quartiles (odds ratio, 1.33; P = .093) compared with smaller doses. Almost one in five (18%) patients had severe to profound hearing loss. Tinnitus (40% patients) was significantly correlated with reduced hearing at each frequency (P \u3c .001). Noise-induced damage (10% patients) was unaffected by cisplatin dose (P = .59). Hypertension was significantly related (P = .0066) to overall hearing threshold (4 to 12 kHz) in age- and cisplatin dose-adjusted analyses. Middle ear deficits occurred in 22.3% of patients but, as expected, were not related to cytotoxic drug dosage. CONCLUSION:
Follow-up of adult-onset cancer survivors given cisplatin should include routine inquiry for hearing status and tinnitus, referral to audiologists as clinically indicated, and hypertension control. Patients should be urged to avoid noise exposure, ototoxic drugs, and other factors that further damage hearing
Weekly water quality monitoring data for the River Thames (UK) and its major tributaries (2009–2013): the Thames Initiative research platform
The River Thames and 15 of its major tributaries have been monitored at weekly intervals since March 2009. Monitored determinands include major nutrient fractions, anions, cations, metals, pH, alkalinity,
and chlorophyll a and are linked to mean daily river flows at each site. This catchment-wide biogeochemical
monitoring platform captures changes in the water quality of the Thames basin during a period of rapid change, related to increasing pressures (due to a rapidly growing human population, increasing water demand and climate change) and improvements in sewage treatment processes and agricultural practices. The platform provides the research community with a valuable data and modelling resource for furthering our understanding of pollution sources and dynamics, as well as interactions between water quality and aquatic ecology. Combining Thames Initiative data with previous (non-continuous) monitoring data sets from many common study sites, dating back to 1997, has shown that there have been major reductions in phosphorus concentrations at most sites, occurring at low river flow, and these are principally due to reduced loadings from sewage treatment works (STWs). This ongoing monitoring programme will provide the vital underpinning environmental data required to best manage
this vital drinking water resource, which is key for the sustainability of the city of London and the wider UK economy. The Thames Initiative data set is freely available from the Centre for Ecology and Hydrology’s (CEH)Environmental Information Data Centre at https://doi.org/10.5285/e4c300b1-8bc3-4df2-b23a-e72e67eef2fd
Nutrient and microbial water quality of the upper Ganga river, India: identification of pollution sources
The Ganga River is facing mounting environmental pressures due to rapidly increasing human population, urbanisation, industrialisation and agricultural intensification, resulting in worsening water quality, ecological status and impacts on human health. A combined inorganic chemical, algal and bacterial survey (using flow cytometry and 16S rRNA gene sequencing) along the upper and middle Ganga (from the Himalayan foothills to Kanpur) was conducted under pre-monsoon conditions. The upper Ganga had total phosphorus (TP) and total dissolved nitrogen concentrations of less than 100 μg l−1 and 1.0 mg l−1, but water quality declined at Kannauj (TP = 420 μg l−1) due to major nutrient pollution inputs from human-impacted tributaries (principally the Ramganga and Kali Rivers). The phosphorus and nitrogen loads in these two tributaries and the Yamuna were dominated by soluble reactive phosphorus and ammonium, with high bacterial loads and large numbers of taxa indicative of pathogen and faecal organisms, strongly suggesting sewage pollution sources. The high nutrient concentrations, low flows, warm water and high solar radiation resulted in major algal blooms in the Kali and Ramganga, which greatly impacted the Ganga. Microbial communities were dominated by members of the Phylum Proteobacteria, Bacteriodetes and Cyanobacteria, with communities showing a clear upstream to downstream transition in community composition. To improve the water quality of the middle Ganga, and decrease ecological and human health risks, future mitigation must reduce urban wastewater inputs in the urbanised tributaries of the Ramganga, Kali and Yamuna Rivers
Meat and Nicotinamide:A Causal Role in Human Evolution, History, and Demographics
Hunting for meat was a critical step in all animal and human evolution. A key brain-trophic element in meat is vitamin B 3 /nicotinamide. The supply of meat and nicotinamide steadily increased from the Cambrian origin of animal predators ratcheting ever larger brains. This culminated in the 3-million-year evolution of Homo sapiens and our overall demographic success. We view human evolution, recent history, and agricultural and demographic transitions in the light of meat and nicotinamide intake. A biochemical and immunological switch is highlighted that affects fertility in the ‘de novo’ tryptophan-to-kynurenine-nicotinamide ‘immune tolerance’ pathway. Longevity relates to nicotinamide adenine dinucleotide consumer pathways. High meat intake correlates with moderate fertility, high intelligence, good health, and longevity with consequent population stability, whereas low meat/high cereal intake (short of starvation) correlates with high fertility, disease, and population booms and busts. Too high a meat intake and fertility falls below replacement levels. Reducing variances in meat consumption might help stabilise population growth and improve human capital
Influence of rural land use on streamwater nutrients and their ecological significance
Concentrations and loads of N and P fractions were examined for lowland rivers,the Wye and Avon, draining a range of representative agricultural land-use types in two
major UK river basins. Data collected over a 2-year period demonstrated important diffuse agricultural source contributions to N and P loads in these rivers. Ground water provided a major source of total dissolved nitrogen (TDN) loads, whereas near-surface sources provided a major contribution to total phosphorus (TP) loads. In terms of aquatic ecology, concentrations of nutrients, at times of eutrophication risk (spring and summer low flows) were of key environmental and management significance. Agricultural diffuse sources provided the major source of long-term P loads across the two basins. However, the results demonstrated the dominance of point-source contributions to TP and SRP concentrations at times of ecological risk. Point sources typically ‘tip the balance’ of dissolved inorganic P (soluble reactive P, SRP) above the 100 lg l1 guideline value indicative of eutrophication risk. The significance of point sources for TP and SRP concentrations was shown by (a) the strong correlations between TP, SRP and B concentrations, using B as a tracer of sewage effluent, (b) the dominant contribution of SRP to TP concentrations and (c) the predominant pattern of dilution of SRP and B with flow. The clean Chalk streams draining low intensity grassland in
areas of the Avon with sparse human settlement were oligotrophic and P limited with low SRP concentrations under spring and summer baseflows attributable to groundwater sources. The data provide important insights into the ecological functioning of different lowland
stream systems. There was evidence of greater SRP losses and N-limitation in a stream which drains a pond system, demonstrating the importance of longer water residence times for biological nutrient uptake
Recovery of sulfate saturated soils in the Plynlimon catchments, mid-Wales following reductions in atmospheric S inputs from the 1980s to 2011
Sulfate adsorption capacity of B-horizons of base-poor, predominantly stagnopodzol, soils from the Plynlimon catchments, mid-Wales was determined by combination of laboratory adsorption and desorption isotherms. Results show that sulfate adsorption capacity of a range of stagnopodzol (Histic-stagno-podzol (Leptic), WRB), brown podzolic soil (Histic-umbrisol (Leptic), WRB) and stagnohumic gley (Histic-stagno-gleysol, WRB) B-horizons was positively related to the amounts of extractable (pyrophosphate and oxalate) Fe + Al, with the stagnopodzol and brown podzolic soil Bs horizon having the largest adsorption capacity and stagnohumic gley Bg horizon the smallest adsorption capacity. Results show that dissolved organic carbon (DOC) has a negative but limited effect on sulfate adsorption in these soils. Results obtained from a set of historical soil samples revealed that the grassland brown podzolic soil Bs horizon and afforested stagnopodzol Bs horizon were highly saturated with sulfate in the 1980s, at 63% and 89% respectively, whereas data from some recently sampled soil from two sites revisited in 2010–11 indicates that percentage sulfate adsorption saturation has since fallen substantially, to 41% and 50% respectively. Between 1984 and 2009 the annual rainfall-weighted mean excess SO4-S concentration in bulk precipitation declined linearly from 0.37 mg S l−1 to 0.17 mg S l−1. Over the same period, flow weighted annual mean stream water SO4-S concentrations decreased approximately linearly from 1.47 mg S l−1 to 0.97 mg S l−1 in the plantation afforested Hafren catchment compared to a drop from 1.25 to 0.69 mg S l−1 in the adjacent moorland catchment of the Afon Gwy. In flux terms, the mean decrease in annual stream water SO4-S flux has been approximately 0.4 kg S ha−1 yr−1, whilst the recovery in stream water quality in the Afon Cyff grassland catchment has been partly offset by loss of SO4-S by desorption from the soil sulfur pool of approximately 0.2 kg S ha−1 yr−1
High-frequency phosphorus monitoring of the River Kennet, UK: are ecological problems due to intermittent sewage treatment works failures?
The River Kennet in southern England has exhibited excessive benthic algal growth and associated ecological problems, such as loss of macrophytes and invertebrates, since the 1980s. These ecological problems were attributed to regular peaks in phosphorus concentration, which were widely attributed to intermittent failures of the Marlborough sewage treatment works (STW). This study deployed highfrequency phosphorus auto-analysers to monitor the total reactive phosphorus (TRP) concentrations of Marlborough STW final effluent and the downstream River Kennet at hourly and 30 minute resolution respectively, between 2008 and 2009. This monitoring confirmed that the Marlborough STW was operating well within its 1000 mg l-�1 annual mean total phosphorus consent limit, with mean total P and soluble reactive P concentrations of 675 and 345 mg l-�1 respectively. There were two occasions where effluent TRP concentration exceeded 1000 mg l-�1, and only one of these resulted in a peak in TRP concentration of over 100 mg l-�1 in the River Kennet at Mildenhall. The other nine peaks of over 100 mg l-�1 in the River Kennet during the monitoring period were associated with storm events, indicating that
diffuse-source inputs and remobilisation of stored within-channel phosphorus were the cause of the peaks in river concentration, rather than Marlborough STW. The value of high-frequency environmental monitoring and the problems associated with using nutrient auto-analysers in the field
are discussed. Seasonal phosphorus consents for STWs could provide a useful and cost effective means to improve both water quality and river ecology in the upper River Kennet
Within-river nutrient processing in Chalk streams: The Pang and Lambourn, UK
This work examines baseflow nutrient concentrations and loads along two rural Chalk streams, the Pang and Lambourn. Soluble reactive phosphorus (SRP) and boron (B) concentrations in these streams were heavily influenced by point-source inputs and the effects of downstream flow accretion and dilution. Unlike B (which is chemically conservative), SRP loads were also strongly influenced by in-stream processing resulting in uptake of SRP, particularly immediately downstream of sewage effluent discharges, where rates of SRP uptake were highest. For the upper River Pang, up to 80% of SRP loads were lost within 4 km downstream of Compton sewage treatment works (STW) and on the River Lambourn up to 55% of SRP loads were lost within 1.6 km downstream of East Shefford STW. In contrast, nitrate (NO3) concentrations at sites along the Pang and Lambourn were largely controlled by groundwater inputs and plant uptake during periods of high photosynthetic activity in spring and summer and silicon (Si) by diatom uptake in April/May. There were net gains in NO3 loads along the river reaches, as a result of volumetric increases in groundwater discharge, and, compared with SRP, the role of in-stream processing of NO3 appeared low.
Examination of SRP exchange by bed sediment and uptake of SRP into algal biofilms indicated that biofilms accounted for only a very small percentage of in-stream P-uptake, but that bed sediment SRP-exchanges had a more important control on baseflow SRP concentrations and loads. Point source P remediation at East Shefford STW, by removal of P from final effluent (P-stripping), resulted in 70–90% reductions in river-water SRP loads. After introduction of P-stripping at East Shefford STW, bed sediments immediately downstream of the STW switched from being net sinks to net sources of SRP. Our results show that, in the immediate aftermath of P-stripping, bed sediment SRP-release was responsible for a 30 μg-P l−1 rise in river-water SRP along this reach. While this increase in SRP concentration, as a result of bed sediment SRP release, is potentially ecologically significant, it is small in relation to the increase in SRP concentrations from effluent prior to P-stripping, which resulted in increases in SRP concentration of up to 500 μg-P l−1. There was a six-month lag between the introduction of P-stripping at East Shefford STW and bed sediment EPC0 recovering to equilibrium levels with the overlying river water (and thus negligible SRP release). Recovery of bed sediments to equilibrium levels is likely to have occurred as a result of winnowing and removal of high-EPC0 sediment and delivery of lower EPC0 sediment from upstream. Under higher/more variable flow conditions and greater rates of in-channel sediment erosion/delivery, more rapid recovery of bed sediment EPC0 levels following P-stripping might be expected
Identifying priorities for nutrient mitigation using river concentration-flow relationships: the Thames basin, UK
The introduction of tertiary treatment to many of the sewage treatment works (STW) across the Thames basin in southern England has resulted in major reductions in river phosphorus (P) concentrations. Despite this, excessive phytoplankton growth is still a problem in the River Thames and many of its tributaries. There is an urgent need to determine if future resources should focus on P removal from the remaining STW, or on reducing agricultural inputs, to improve ecological status. Nutrient concentration-flow relationships for monitoring sites along the River Thames and 15 of its major tributaries were used to estimate the relative inputs of phosphorus and nitrogen from continuous (sewage point sources) and rain-related (diffuse and within-channel) sources, using the Load Apportionment Model (LAM). The model showed that diffuse sources and remobilisation of within-channel phosphorus contributed the majority of the annual P load at all monitoring sites. However, the majority of rivers in the Thames basin are still dominated by STW P inputs during the ecologically-sensitive spring-autumn growing season. Therefore, further STW improvements would be the most effective way of improving water quality and ecological status along the length of the River Thames, and 12 of the 15 tributaries. The LAM outputs were in agreement with other indicators of sewage input, such as sewered population density, phosphorus speciation and boron concentration. The majority of N inputs were from diffuse sources, and LAM suggests that introducing mitigation measures to reduce inputs from agriculture and groundwater would be most appropriate for all but one monitoring site in this study. The utilisation of nutrient concentration-flow data and LAM provide a simple, rapid and effective screening tool for determining nutrient sources and most effective mitigation options