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While it is recognized that groundwater contaminant plumes can impact surface waters, there remains little information on the magnitude, spatial extent, and especially temporal variability of the resulting exposure to the variety of aquatic organisms, particularly for stagnant surface waters (e.g., ponds). The present study of a historic landfill plume discharging to a pond investigated contaminant exposure to multiple aquatic zones (endobenthic, epibenthic, pelagic) over approximately 1 year within a temperate climate. Landfill tracers included the artificial sweetener saccharin, ammonium, chloride, and specific conductance. Sampling of pond sediment porewater (upwelling groundwater) and continuous geophysical imaging of the subsurface showed a relatively stable plume footprint covering approximately 26% of the pond, although with spatially varying leachate composition, revealing year‐round exposure to endobenthic (within sediments) organisms. Substantial and variable contaminant exposure to epibenthic organisms within the plume footprint was shown by elevated specific conductance measured directly above the sediment interface. Exposure varied daily at times and increased through winter to values representing undiluted plume groundwater. Exposure to pelagic organisms (overlying water) covered a larger area (~50%) due to in‐pond circulation. The stream outlet concentrations were stable at approximately 10 times dilution for chloride and saccharin, but were substantially less in summer for ammonium due to in‐pond processes. Whereas groundwater contaminants are typically assumed elevated at base flows, the outlet stream contaminant mass discharges to downstream receptors were notably higher in winter than summer, following stream flow patterns. Insights from the present study into the timings and locations of contaminant plume exposure to multiple ecological zones of a pond can provide guidance to contaminated site and aquatic ecosystem managers on improved monitoring, assessment, and remediation protocols. Environ Toxicol Chem 2023;42:1667–1684. © 2023 His Majesty the King in Right of Canada and The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Environment and Climate Change Canada. [ABSTRACT FROM AUTHOR]

Monitoring of a seasonal‐use, on‐site wastewater disposal system (septic system) in Canada, over a 33‐year period from 1988 to 2021, showed that during recent sampling the groundwater plume had TIN (total inorganic nitrogen) averaging 12.2 mg/L that was not significantly different than early values, representing 80% removal, whereas SRP (soluble reactive phosphate), although higher than early values averaging 0.08 mg/L, was still 99% lower than the effluent concentration. Evidence suggests that the anammox reaction and possibly also denitrification contribute to TIN removal, whereas SRP removal is primarily the result of mineral precipitation. Most of the removal occurs in close proximity to the drainfield infiltration pipes (within about 1 m) demonstrating that reaction rates are relatively fast in the context of typical groundwater plume residence times. This long‐term consistency demonstrates that sustainable nutrient treatment can be achieved with conventional on‐site wastewater disposal systems that have low capital costs and require minimal energy input and maintenance. [ABSTRACT FROM AUTHOR]

We investigated the influence of land cover on nutrient concentrations (295 samples) in headwater streams over a 2‐year period in 10 agriculture‐dominated subcatchments (163–8373 ha) in southern Ontario Canada. In this region, monitoring and research on nutrient dynamics in headwater wetlands is sparse. Our results indicated a significant positive correlation (Pearson coefficient ρ = 0.320) between soluble reactive phosphorus (SRP) in the headwater streams and the percentage of wetlands in these agriculture‐dominated catchments. This result suggests that headwater wetlands, and other wet riparian zones, are key sources of SRP in the headwater streams. Nitrate concentrations were positively correlated with % agricultural land cover (ρ = 0.316), consistent with previous studies, while SRP concentrations were negatively correlated with % agricultural land cover (ρ = −0.325). There was a significant positive correlation between SRP concentrations and discharge in some of the streams. Seasonal SRP trends appear to be closely related to temperature‐dependent seasonal changes in redox conditions, including levels of dissolved O2. Surficial geology had some influence on nitrate concentrations in the streams, which tended to be higher in catchments dominated by glacial till (till terrain), compared to catchments with extensive areas of outwash sand, in addition to till terrain. [ABSTRACT FROM AUTHOR]

Leachate‐contaminated groundwater from historical municipal landfills, typically lacking engineered liners and leachate collection systems, poses a threat to nearby urban streams, particularly to benthic ecosystems. Effective monitoring and assessment of such sites requires understanding of the spatial patterns (i.e., two‐dimensional footprint) of contaminated groundwater discharge and associated controlling factors. However, discharges from groundwater contaminated by modern wastewater can complicate site assessments. The objectives of this study were to (1) demonstrate the use of artificial sweeteners (AS): saccharin (SAC), cyclamate (CYC), acesulfame (ACE), and sucralose (SUC), to distinguish groundwater discharge areas influenced by historic landfill leachate (elevated SAC and sometimes CYC; low ACE and SUC concentrations) from those influenced by wastewater (high ACE and SUC concentrations), and (2) investigate contaminant discharge patterns for two gaining urban stream reaches adjacent historic landfills at base flows. Contaminant discharge patterns revealed by the AS were strongly controlled by hyporheic flow (low AS concentrations), particularly for the straight reach, and stream sinuosity, particularly for the meandering reach. These patterns were different and the contaminant footprint coverage (<25% of streambed area) much less than most past studies (typically >50% coverage), likely due to the homogeneous streambed‐aquifer conditions and shallow, narrow landfill plume in this setting. [ABSTRACT FROM AUTHOR]

Concepts and terms used in previous multidisciplinary studies of tile‐drained aquitard‐dominated catchments (TDADC) are inconsistent and confusing. We provide a well‐defined, comprehensive conceptual model of the subsurface hydrology of TDADC by selecting seven mutually compatible and consistent concepts. These concepts are: (1) groundwater as the main source of baseflow in headwater streams, (2) dominance of 'pre‐event' water in stormflow, (3) importance of both macropores and matrix, (4) changes in flowpaths with rate of stream discharge, (5) dominance of shallow, lateral subsurface flow, (6) interactive nature of subsurface water, (7) transpiration of groundwater. This conceptual model was successfully 'field‐tested' by examining data collected in a TDADC in a rural area of southern Ontario, Canada. The data consist mainly of chemical and isotopes tracers in water samples (headwater streams, groundwater, precipitation, tile water, soil‐surface water), supplemented by water levels and meteorological data. [ABSTRACT FROM AUTHOR]

The presence of artificial sweeteners in environmental samples is increasingly used to detect wastewater (and recently landfill leachate) in rivers, lakes and groundwater. Through routine laboratory quality assurance/quality control procedures, it was discovered that some syringe-tip filters leach saccharin when used to process water samples. We subsequently tested several brands of filters to determine if they leached any of the four common artificial sweeteners analyzed in environmental samples, acesulfame, saccharin, cyclamate, and sucralose. Of the six types of filters tested, only one brand was a source of artificial sweeteners and the only artificial sweetener found was saccharin. The source of the saccharin in the filters is unknown but it is likely the result of some step in the manufacturing process. The saccharin was typically removed from these filters using a distilled water rinse of 13 mL or less. As a precaution, filters should be pre-tested for the presence of saccharin and/or filters should be flushed with distilled water or sample prior to the collection of water samples for artificial sweetener analyses. [ABSTRACT FROM AUTHOR]

BACKGROUND The objective of this study was to investigate the occurrence of glyphosate residues (glyphosate and its metabolite AMPA) in shallow groundwater in a catchment dominated by agriculture, and to examine the potential for this groundwater to store and transmit these compounds to surface waters. RESULTS Glyphosate residues were found in some of the groundwater samples collected in riparian (surface seeps), upland (mostly <20 m below ground) and wetland settings (<3 m below ground). Overall, glyphosate and AMPA were detected in 10.5 and 5.0%, respectively, of the groundwater samples analyzed as part of this study. All concentrations of glyphosate were well below Canadian guidelines for drinking water quality and for protection of aquatic life. Seasonal differences in concentrations in riparian seeps were possibly related to cycles of weather, herbicide application and degradation of glyphosate. Highest concentrations were at upland sites (663 ng L−1 of glyphosate, 698 ng L−1 of AMPA), apparently related to localized applications. Most glyphosate detections in wetlands were >0.5 km distant from possible areas of application, and, combined with other factors, suggest an atmospheric transport and deposition delivery mechanism. In both upland and wetland settings, highest glyphosate concentrations were sometimes not at the shallowest depths, indicating influence of hydrological factors. CONCLUSION The glyphosate/ AMPA detections in riparian seeps demonstrated that these compounds are persistent enough to allow groundwater to store and transmit glyphosate residues to surface waters. Detections in the wetlands support earlier evidence that atmospheric transport and deposition may lead to glyphosate contamination of environments not intended as targets of applications. This interpretation is further supported by detections of both glyphosate and AMPA in precipitation samples collected in the same watershed. © 2016 Her Majesty the Queen in Right of Canada Pest Management Science © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Monitoring of a well-defined septic system groundwater plume and groundwater discharging to two urban streams located in southern Ontario, Canada, provided evidence of natural attenuation of background low level (ng/L) perchlorate ( ClO4−) under denitrifying conditions in the field. The septic system site at Long Point contains ClO4− from a mix of waste water, atmospheric deposition, and periodic use of fireworks, while the nitrate plume indicates active denitrification. Plume nitrate ( NO3−-N) concentrations of up to 103 mg/L declined with depth and downgradient of the tile bed due to denitrification and anammox activity, and the plume was almost completely denitrified beyond 35 m from the tile bed. The ClO4− natural attenuation occurs at the site only when NO3−-N concentrations are <0.3 mg/L, after which ClO4− concentrations decline abruptly from 187 ± 202 to 11 ± 15 ng/L. A similar pattern between NO3−-N and ClO4− was found in groundwater discharging to the two urban streams. These findings suggest that natural attenuation (i.e., biodegradation) of ClO4− may be commonplace in denitrified aquifers with appropriate electron donors present, and thus, should be considered as a remediation option for ClO4− contaminated groundwater. [ABSTRACT FROM AUTHOR]

Four artificial sweeteners, acesulfame, sucralose, cyclamate, and saccharin were detected in a large septic plume at Long Point, Ontario, Canada. The pattern of sweetener detections in the groundwater indicated that they were derived from waste water seepage from a large septic system at the site. Acesulfame was pervasive in the septic plume, whereas the other three sweeteners have been attenuated, probably by microbial degradation. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to ascertain patients' and health professionals' requirements from a rheumatology helpline and how such a service should be delivered. Methods: Self-completed questionnaires were administered to both users of rheumatology helplines, patients and health professionals (HPs), and providers of rheumatology services at five UK NHS trusts. Additional data were sought from experts in the field. Information was elicited on access to the service, preferred waiting time for response to a call, acceptability of an answerphone and choice of HP responding. Quantitative data were analysed using percentages and Chi-squared tests. Open questions were analysed as free text responses, and organized into clusters of themes. Results: A total of 607 questionnaires were returned, 523 from users (411 patients, 112 health professionals) and 84 from providers. There were no significant differences across the five Trusts. The top six reasons for patients contacting the helpline were: advice on changes in condition, drug information, understanding symptoms, blood results, information on diagnosis, and appointment queries. All groups recommended a return call on the same day and were happy to leave an answerphone message. HP users requested additional access via e-mail and fax. Rheumatology practitioners were deemed the most appropriate personnel to staff a helpline. Conclusions: The findings of this study have contributed a valuable insight into the essential components of a rheumatology helpline service from a user and provider perspective. These data will add to existing recommendations for the management of a rheumatology helpline service and ultimately contribute to a proposal for national guidelines. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Anterior morphogens have long been postulated to function in early pattern formation in several insect taxa. Genetic studies inDrosophilarevealed that the Bicoid protein performs as such in the fly. Maternally providedbicoid(bcd) mRNA is localized at the anterior pole of the oocyte and, upon fertilization, acts as the source of a morphogenetic gradient of Bicoid protein. Despite its central role inDrosophila, it is believed thatbicoidarose rather recently during dipteran evolution through duplication of theHox3orthologzen.Here we show that in the red flour beetleTribolium castaneum, RNAs of the homologs of theDrosophilatranscription factorseagle(Tc′ eagle) andpangolin(Tc′ pan) are maternally localized at the anterior pole of the egg. It is possible that underlying mechanisms for the anterior localization of maternal RNAs evolved independently in the two clades. However, considering the complexity of the process inDrosophila, it is more tempting to speculate that the molecular machinery evolved only once during insect evolution. Under this assumption, it was present beforebicoidevolved as an anterior morphogen. To become concentrated at the anterior pole of the eggbicoidmay only have had to acquire a signal sequence that was recognized by the preexisting localization machinery. Although we were not able to demonstrate a function in early embryogenesis forTc′ eagleorTc′ pan, our findings suggest that other factors likely function as anterior determinants inTribolium, and other nondipteran insects. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to investigate the impact of the pilot education programmes, entitled `Focus on Lupus' and `Focus on Scleroderma', upon participants' management of their disease, Methods: Five people with lupus and five with scleroderma were invited to take part in individual semi-structured interviews. Qualitative analysis of transcripts was performed using a framework approach. Views relating to changes in knowledge and behaviour, increased empowerment, meeting others and the format and delivery of the programmes were explored. Results: Analysis of the interviews revealed overall satisfaction with both programmes, however people with lupus had more positive feelings about their attendance. Both disease groups considered it valuable to meet others with the same disease and welcomed the involvement of a patient educator within the programme planning team. The main difference between the two groups concerned behaviour change. The lupus group revealed more definite life changes. Participants unanimously regarded the format of the programme highly and most were satisfied with the content. [ABSTRACT FROM AUTHOR]

SUMMARY Null mutations in the Drosophila melanogaster homeotic gene proboscipedia (pb) cause transformation of the adult labial palps to legs. The similar phenotype produced by mutations in the Tribolium castaneum homeotic complex (HOMC) gene maxillopedia (mxp) has led to suggestions that the two genes may be orthologous. We have cloned the Tribolium ortholog of pb, which predicts a protein with a homeodomain identical to that of Drosophila Pb. The two proteins also share several additional regions of identity, including an N-box, a motif unique to Pb orthologs. We have identified a frameshift mutation within Tribolium pb associated with an mxp null mutation, demonstrating that Tribolium pb corresponds to the mxp genetic locus. Thus, we will refer to the cloned gene as mxp. In addition, we have begun to construct a molecular map of the Tribolium HOMC. Two overlapping BAC clones which span the mxp locus also include the Tribolium labial ortholog (Tclabial ) and part of Tczerknüllt, indicating that the order of these genes in the HOMC is conserved between Drosophila and Tribolium. [ABSTRACT FROM AUTHOR]

Gene product distribution is often used to infer developmental similarities and differences in animals with evolutionarily diverse body plans. However, to address commonalties of developmental mechanisms, what is really needed is a method to assess and compare gene function in divergent organisms. This requires mutations eliminating gene function. Such mutations are often difficult to obtain, even in organisms amenable to genetic analysis. To address this issue we have investigated the use of double-stranded RNA interference to phenocopy null mutations. We show that RNA interference can be used to phenocopy mutations of the Deformed orthologues in Drosophila and Tribolium. We discuss the possible use of this technique for comparisons of developmental mechanisms in organisms with differing ontogenies. [ABSTRACT FROM AUTHOR]

Life table data and intrinsic rates of increase were obtained for Myzus persicae, Brachycaudus helichrysi and Macrosiphoniella sanborni on chrysanthemum and for Aphis gossypii on cucumber, at 18 and 24° C, with daylengths of 8 and 16 h and light intensities of 800, 4000 and 8000 lux, in all combinations, using a modified Munger cell technique. In General, Aphis gossypii matured earliest and produced most young, followed by Myzus persicae. Pre-reproductive time, mean generation time and longevity were prolonged by low temperature, but were little affected by other factors. The number of progeny was greatly reduced by poor light. Daylength had no general effect but produced strong and complex interactions with other factors. [ABSTRACT FROM AUTHOR]