602 research outputs found

    Carbon and nitrogen dynamics: Greenhouse gases in groundwater beneath a constructed wetland treating municipal wastewater

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    Conference oral presentationConstructed wetlands (CW) act as nitrogen (N) sinks and reactors facilitating a number of physical, chemical and biological processes. The N removal efficiency of through-flowing water in such systems when used to treat municipal wastewater is variable. Their overall removal efficiencies do not specifically explain which N species have been removed by physical attenuation, and by biological assimilation or transformation to other forms. A wider understanding of how N removal occurs would help elucidate how losses of N and associated gases from CW impact on water and air quality. The objective of this study is to investigate the C and N cycling processes in the porewater of soils immediately adjacent, up-gradient and down- gradient to helophyte —vegetated CW cells

    EIMERIOSIS IN POULTRY OF RAWALPINDI/ISLAMABAD AREA

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    This study was designed to determine the prevalence of eimeriosis in poultry and identify potential risk factors for its spread in Rawalpindi/Islamabad area of Pakistan. Of 359 gut samples (suspected for harbouring eimeriosis) examined, 258 (71.86%) were found infected. Four species of Eimeria (E. maxima, 34.10%, E. tenella, 30.62%, E. mitis, 13.95% and E. necatrix, 7.75%) were recorded. The prevalence of eimeriosis was highest in the month of September (89.74%), while lowest during June (28.57%). The disease was more common at the farms where the litter was wet and not managed properly

    Mustard catch crop enhances denitrification in shallow groundwater beneath a spring barley field

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    The study was funded by Department of Agriculture and Food through the Research Stimulus Fund Programme (Grant RSF 06383) in collaboration with the Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, Ireland.peer-reviewedOver-winter green cover crops have been reported to increase dissolved organic carbon (DOC) concentrations in groundwater, which can be used as an energy source for denitrifiers. This study investigates the impact of a mustard catch crop on in situ denitrification and nitrous oxide (N2O) emissions from an aquifer overlain by arable land. Denitrification rates and N2O-N/(N2O-N + N2-N) mole fractions were measured in situ with a push–pull method in shallow groundwater under a spring barley system in experimental plots with and without a mustard cover crop. The results suggest that a mustard cover crop could substantially enhance reduction of groundwater nitrate NO3--N via denitrification without significantly increasing N2O emissions. Mean total denitrification (TDN) rates below mustard cover crop and no cover crop were 7.61 and 0.002 μg kg−1 d−1, respectively. Estimated N2O-N/(N2O-N + N2-N) ratios, being 0.001 and 1.0 below mustard cover crop and no cover crop respectively, indicate that denitrification below mustard cover crop reduces N2O to N2, unlike the plot with no cover crop. The observed enhanced denitrification under the mustard cover crop may result from the higher groundwater DOC under mustard cover crop (1.53 mg L−1) than no cover crop (0.90 mg L−1) being added by the root exudates and root masses of mustard. This study gives insights into the missing piece in agricultural nitrogen (N) balance and groundwater derived N2O emissions under arable land and thus helps minimise the uncertainty in agricultural N and N2O-N balances

    Effect of an agri-environmental measure on nitrate leaching from a beef farming system in Ireland

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    peer-reviewedAgricultural nitrogen (N) management remains a key environmental challenge. Improving N management is a matter of urgency to reduce the serious ecological consequences of the reactive N. Nitrate (NO3−–N) leaching was measured under suckler beef production systems stocked at two intensities: (1) intensive, 210 kg organic N ha−1 with two cut silage harvests; and (2) rural environmental protection scheme (REPS), 170 kg organic N ha−1 with one cut silage harvest. Three replicate plots of each treatment were instrumented with ceramic cups (8 per plot), randomly placed within each plot at a depth of 1 m to collect soil solution for NO3−–N at 50 kPa suction to collecting vessels one week prior to sampling. Samples were taken on a total of 53 sampling dates over 3 winter drainage periods (2002/03, 2003/04 and 2004/05). Over the course of the experiment the mean annual soil solution NO3−–N concentration exceeded the MAC twice out of 15 means (5 treatments over 3 years). The REPS grazing and silage sub treatments had significantly lower mean annual soil solution total oxidized N (TON) concentrations than the respective intensive treatments in years 2 and 3. Annual total NO3−–N losses over the three years in intensive and REPS systems ranged from 55 to 71 and 15 to 20 kg N ha−1, respectively. Mean N surpluses in intensive and REPS systems were 210 and 95 kg ha−1, respectively with the corresponding mean N inputs of 272 and 124 kg N ha−1. The reduction in N inputs under the REPS system results in lower N leaching losses and contributed to a significant reduction in pressures on water quality

    Comparison of the Effect of Short-Term Consumption of Probiotic (Bacillus Coagulans) and Ordinary Cake on Salivary Streptococcus Mutans

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    BACKGROUND AND OBJECTIVE: Consumption of food causes changes in oral flora. Foods that create an appropriate media for Streptococcus mutans and other cariogenic microflora, cause increase the rate of tooth caries. The aim of this study was the assessment of short-term consumption of probiotic cake (contain Bacillus coagulans) on salivary streptococcus mutans count and comparison with ordinary cake. METHODS: A cross over blind study was conducted on 30 healthy adult volunteers in two groups (16 males and 14 females). The first group ate probiotic cake (75 grams daily) for 1 week and after 2 weeks wash out period, they ate ordinary cake. The second group first ate ordinary cake and after 2 weeks wash out period, they ate probiotic cake (75 grams daily). Non-stimulating salivary samples, before (as baseline) and after eating probiotic and ordinary cake, were collected. Then counting of streptococcus mutans was done with colony counter. FINDINGS: Of the 30 patients, 16 (53.33%) were male and 14 (46.67%) were female with an average age of 40.86±17.15 years. Number of Streptococcus mutans in baseline saliva samples was (7.872±1.430)106 CFU/ml and in the saliva samples after consumption of probiotic cake was (4.652±0.841)106 CFU/ml and in saliva samples after consumption of ordinary cake was (21.386±3.895)106 CFU/ml. There was no significantly difference between mutants count before and after eating probiotic cake (p=0.769) but after consumption of ordinary cake than probiotic cake the count of streptococcus increased significantly (21.3±39.9 compared with 4.65±0.84) (p=0.032). CONCLUSION: Based on the results of this study, the addition of probiotic bacteria to sweet and high-consumption foods can reduce the adverse effects of foods such as cakes on oral health

    An evaluation of urine patch simulation methods for nitrous oxide emission measurement

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    peer-reviewedGlobal nitrous oxide (N2O) inventory estimates for pasture systems are refined based on measurements of N2O loss from simulated urine patches. A variety of methods are used for patch simulation but they frequently use a uniform wetted area (UWA), often smaller than a bovine urine patch. However, natural patches follow non-uniform infiltration patterns expanding naturally from a point of deposit with a non-wetted zone of influence. Using 2 litres of urine the UWA method was compared, using a 0·156 m2 collar, with a naturally expanding effective area (NEEA) method, using a 0·462 m2 collar under high (HL) and low (LL) N2O loss conditions. The method chosen affects urine nitrogen (N) loading to the soil. Under HL the UWA method induced a N2O-N loss of 280·6 mg/patch, significantly less than the 434·8 mg/patch loss for the NEEA method, for the same simulated urination. Under LL there was no method effect. Efforts should be made to employ patch simulation methods, which mimic natural deposits and can be achieved, at least in part, by: (a) Using a urine volume and N content similar to that of the animal of interest. (b) Allowing natural infiltration of the chosen urine volume to permit tapering towards the edges. (c) Measuring from the zone of influence in addition to the wetted area, i.e. the patch effective area

    In situ denitrification rates in shallow groundwater beneath a springbarley - mustard cover crop system

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    Abstract of Conference poster presentatio

    An expert system for diabetes prediction using auto tuned multi-layer perceptron

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    Medical Expert Systems is an active research area where data analysts and medical experts are continuously collaborating to make these systems more accurate and therefore, more useful in real life. Recent surveys by World Health Organization indicated a great increase in number of diabetic patients and the deaths that are attributed to diabetes each year. Therefore, early diagnosis of diabetes is a major concern among researchers and practitioners. The paper presents an application of automatic multilayer perceptron (AutoMLP) which is combined with an outlier detection method Enhanced Class Outlier Detection using distance based algorithm to create a novel prediction framework. AutoMLP is auto-tunable and performs parameter optimization automatically on the run during training process, which otherwise requires human intervention. Our framework performs outlier detection during pre-processing of data. A series of experiments are performed publicly available dataset: UCI (Prima Indian) and system achieved an accuracy of 88.7% which bests the highest reported results

    Groundwater nitrate reduction versus dissolved gas production: A tale of two catchments

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    peer-reviewedAt the catchment scale, a complex mosaic of environmental, hydrogeological and physicochemical characteristics combine to regulate the distribution of groundwater and stream nitrate (NO3−). The efficiency of NO3− removal (via denitrification) versus the ratio of accumulated reaction products, dinitrogen (excess N2) & nitrous oxide (N2O), remains poorly understood. Groundwater was investigated in two well drained agricultural catchments (10 km2) in Ireland with contrasting subsurface lithologies (sandstone vs. slate) and landuse. Denitrification capacity was assessed by measuring concentration and distribution patterns of nitrogen (N) species, aquifer hydrogeochemistry, stable isotope signatures and aquifer hydraulic properties. A hierarchy of scale whereby physical factors including agronomy, water table elevation and permeability determined the hydrogeochemical signature of the aquifers was observed. This hydrogeochemical signature acted as the dominant control on denitrification reaction progress. High permeability, aerobic conditions and a lack of bacterial energy sources in the slate catchment resulted in low denitrification reaction progress (0–32%), high NO3− and comparatively low N2O emission factors (EF5g1). In the sandstone catchment denitrification progress ranged from 4 to 94% and was highly dependent on permeability, water table elevation, dissolved oxygen concentration solid phase bacterial energy sources. Denitrification of NO3 − to N2 occurred in anaerobic conditions, while at intermediate dissolved oxygen; N2O was the dominant reaction product. EF5g1 (mean: 0.0018) in the denitrifying sandstone catchment was 32% less than the IPCC default. The denitrification observations across catchments were supported by stable isotope signatures. Stream NO3− occurrence was 32% lower in the sandstone catchment even though N loading was substantially higher than the slate catchment.Teagasc Walsh Fellowship Programm
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