Documenting success stories of management of phosphorus emissions at catchment scale: an example from the pilot river Odense, Denmark.

Documentation of the effects of different mitigation measures adopted at different scales to reduce phosphorus (P) loadings to surface waters is needed to help catchment managers select the best management practices. Water quality monitoring data from the outlets of two paired catchments (the river Odense catchment versus a neighbouring control catchment) on the island of Funen, Denmark, showed significantly different trends in annual flow-weighted P concentrations during the period 2000-2013. A significant downward trend in flow-weighted particulate P (PP) concentrations (0.051 mg P L-1) and loss (0.155 kg P ha-1) was detected for the river Odense catchment, whereas a similar trend did not emerge in the control catchment. The observed differences in PP reductions may be due to wetlands acting as P sinks since wetland restoration activities have been much more comprehensive in the river Odense catchment (1.8 ha wetlands km-2) than in the control catchment (0.5 ha wetland km-2). The excess downward trend in total P and PP in the river Odense catchment (5,600 kg P and 3,700 kg P) is corroborated by extrapolating the results from a mass-balance study and 10 years of in situ measurements of P storage (3,700 kg P and 15,000 kg P).

Successful reduction of diffuse nitrogen emissions at catchment scale: example from the pilot River Odense, Denmark.

Land-based total nitrogen (N) loadings to Danish coastal waters have been markedly reduced since 2000. This has been achieved by general measures reducing discharges from all point sources and N leaching from farmed land supplemented with more local and targeted mitigation measures such as restoration of wetlands to increase the catchment-specific N retention. In the catchment of River Odense, restoration of wetlands has been extensive. Thus, in the major gauged catchment (485 km(2)) eleven wetlands (860 ha) have been restored since 2000. A comparison of data on N concentrations and loss from a gauging station in the River Odense with data from a control catchment (772 km(2)), in which a significantly less intensive wetland restoration programme has been undertaken, showed an excess downward trend in N, amounting to 124 t N yr(-1), which can be ascribed to the intensive wetland restoration programme carried out in the River Odense catchment. In total, the N load in the River Odense has been reduced by 377 t N yr(-1) (39%) since 2000. The observed downward trend is supported by monitoring data from two wetlands restored in 2001 and 2004 in the River Odense catchment.

Phosphorus losses from agricultural areas in river basins: effects and uncertainties of targeted mitigation measures.

In this paper we show the quantitative and relative importance of phosphorus (P) losses from agricultural areas within European river basins and demonstrate the importance of P pathways, linking agricultural source areas to surface water at different scales. Agricultural P losses are increasingly important for the P concentration in most European rivers, lakes, and estuaries, even though the quantity of P lost from agricultural areas in European catchments varies at least one order of magnitude (<0.2 kg P ha(-1) to >2.1 kg P ha(-1)). We focus on the importance of P for the implementation of the EU Water Framework Directive and discuss the benefits, uncertainties, and side effects of the different targeted mitigation measures that can be adopted to combat P losses from agricultural areas in river basins. Experimental evidence of the effects of some of the main targeted mitigation measures hitherto implemented is demonstrated, including: (i) soil tillage changes, (ii) treatment of soils near ditches and streams with iron to reduce P transport from source areas to surface waters, (iii) establishment of buffer zones for retaining P from surface runoff, (iv) restoration of river-floodplain systems to allow natural inundation of riparian areas and deposition of P, and (v) inundation of riparian areas with tile drainage water for P retention. Furthermore, we show how river basin managers can map and analyze the extent and importance of P risk areas, exemplified by four catchments differing in size in Norway, Denmark, and the Netherlands. Finally, we discuss the factors and mechanisms that may delay and/or counteract the responses of mitigation measures for combating P losses from agricultural areas when monitored at the catchment scale.

A reproducible method for the optimum infection of human mononuclear cells and lymphoid cell lines by herpes simplex virus type 1.

Parameters for the infection of human mononuclear cells (MNC) with herpes simplex virus type 1 (HSV-1) were investigated and a procedure was established which resulted in a reproducible optimum number of cells expressing virus-specific cell surface antigens. The number of cells infected was independent of sex of the donor and independent of whether the donor was HSV-seropositive or -seronegative. On the average 18 +/- 6% of HSV-infected MNC from any given donor expressed HSV-specific cell surface antigens. When the standard procedure was applied to a variety of lymphoid cell lines, a high percentage of cells of both B and non-T/non-B lines expressed HSV-specific cell surface antigens, whereas T-cell lines appeared resistant to HSV infection.

A comparison of five rapid direct toxicity assessment methods to determine toxicity of pollutants to activated sludge.

Five rapid direct toxicity assessment methods were used in three European partner countries to determine the toxicity of single toxicants, mixed toxicants and real industrial wastes. The final aim was to protect microbial degradation of organic wastes in biological treatment processes and hence enhance the quality of treated effluents to be discharged to the environment. Nitrification inhibition, Respirometry, Adenosine triphosphate luminescence and Enzyme inhibition were tested utilising activated sludge as the testing matrix. The Vibrio fischeri toxicity test was used as a surrogate to compare the various microbial bioassays. The IC50 (toxicant concentration eliciting a 50% inhibitory effect) was determined for a number of pollutants including single toxicants Cd, Cr, Cu, Zn, 3,5-dichlorophenol, toluene and linear alkylbenzenesulphonate (LAS); a standard mixture of metals and LAS; a standard mixture of organics and LAS, and 16 industrial effluents. The V. fischeri bioassay was also chosen in order to assess quality control of toxicant preparation during testing in the different laboratories of the partner countries. Comparisons of sensitivity, cost of implementation, cost per test, relevance, and ease of use were made. The most sensitive bioassays were V. fischeri and Nitrification inhibition, however, this depended in the main on the pollutant and mixtures tested. It is recommended that during assessment of wastewater toxicity a suite of tests be used rather than reliance on one particular test.

Subsurface tile drainage loss of modern pesticides: field experiment results.

The concentration and loss of two herbicides (bentazone and MCPA), two fungicides (fenpropimorph and propiconazole) and two insecticides (dimethoate and pirimicarb) were measured in tile drainage water from a 2,813 m2 experimental grass field from May to August 2001. Three different pesticides were applied to the field and subsequently a rainfall of 10 mm was simulated during the first experiment and 16 mm during the second experiment. Bromide was applied as a conservative tracer in the first experiment and the concentration of bromide and suspended sediment was also measured in tile drainage water. In the first experiment, maximum concentrations of bentazone, fenpropimorph and dimethoate in drainage water were 5.8 microg l(-1), 0.33 microg l(-1) and 2.29 microg l(-1), respectively. In the second experiment, maximum concentrations for MCPA, propiconazole and pirimicarb were 3.6 microg l(-1), 0.065 microg l(-1), 2.3 microg l(-1), respectively. The loss:applied ratio was highest for bentazone (0.088%) and declined in the order of dimethoate (0.057%), pirimicarb (0.050%), propiconazole (0.0031%) and fenpropimorph (0.00042%). Exposure of the macroinvertebrate species Gammarus pulex to pesticides in the drainage water during the second experiment (exposure time: 7 hours) showed significant mortality/inactivity as compared to an upstream and downstream control.

Temporal specificity of procarbazine in the inhibition of mouse immune responses to allogeneic tumor.

The inhibition of the cellular response of C57Bl/6 mice against allogeneic P815 mastocytoma by procarbazine was shown to be uniquely dependent upon time of administration with respect to antigen. If the drug was given 4 or 6 days after antigen, the development of the T cell effectors was inhibited; if it was given earlier (2 hr or 1 or 2 days after antigen), the response was affected less. In contrast to the immunosuppressive effectiveness of delayed administration of procarbazine, the inhibition of the T cell response by daunorubicin was greatest when the agent was given 2 days after antigen, and that by cyclophosphamide, at the concentrations used, was relatively time independent. Under similar conditions the effects of the three agents on the humoral response were found to be less selective. The inhibition of both responses by procarbazine was shown to be dose dependent and relatively independent of the route of administration.

Human breast cancer and impaired NK cell function.

Recent advances in tumor immunology have led to the discovery of a new lymphoid cell with unique antitumor activity. Natural killer (NK) cells form an antitumor surveillance system and appear to be vital in preventing tumor growth and metastasis in animal models. We studied NK activity in patients with benign and malignant breast disease, using a chromium-51 release microtiter cytotoxicity assay with K562 cells as targets. Compared with benign controls, patients with malignancies had significantly depressed NK-mediated lysis (P less than 0.01). Furthermore, lysis in those with advanced disease (stages II, III, and IV) was significantly less than in those with limited disease (stage I) (P less than 0.01). NK activity was not correlated to estrogen or progesterone receptor states. Positive correlation of a depressed natural killer activity with the extent of tumor spread supports the concept of an NK cell immune surveillance system in breast cancer and emphasizes its importance in this malignancy.

Hematologic and immunologic responses in common marmosets (Callithrix jacchus) infected with Plasmodium knowlesi and Epstein-Barr virus.

The hematologic and immunologic responses to infection with either the Epstein-Barr virus alone or infection with Epstein-Barr virus and Plasmodium knowlesi were studied using common marmosets (Callithrix jacchus). The assays performed included complete blood cell counts, determinations of natural killer cell activity, and determinations of antibody titers to Epstein-Barr virus early antigen, virus capsid antigen and the nuclear antigen. While no animal showed signs of lymphoproliferative disease, it was found that animals infected with Epstein-Barr virus became positive for early antigen, virus capsid antigen and nuclear antigen at low levels. No difference in antibody titers between Epstein-Barr virus infected animals and co-infected animals was observed. An increase also was found in the number of leukocytes in all groups, and an increase in natural killer cells following infection with Epstein-Barr virus. Some depression in natural killer cells was observed in the co-infected animals when compared to Epstein-Barr virus infected animals.

Scanning electron microscopy of human lymphocytes during transformation and subsequent treatment with methotrexate.

Preparations of human peripheral blood lymphocytes containing 72-87% T-cells and 10-16% B-cells were shown by scanning electron microscopy to consist almost exclusively of cells bearing numerous microvilli, whereas thymocytes were of mixed surface morphology, with both smooth and encrusted forms numerous. T-lymphocytes purified on long nylon columns were all covered with numerous short villi. Stimulation with phytohaemagglutinin for 2 days produced T-lymphoblasts almost exclusively, and as the T-cells enlarged the microvilli lengthened, the increase in length reaching 5-fold by day 3. Addition of sufficient methotrexate on day 3 to arrest proliferation (50 nM) caused progressive loss of microvilli from the cell surface, with the eventual production of large numbers of smooth cells, the surfaces of which later became pitted, followed by the complete dissolution of the cell. T-lymphocytes were shown to form rosettes with sheep erythrocytes through direct contact of the cell membranes over a significant area, but when, as a result of methotrexate treatment, the lymphocytes had become denuded of microvilli or had reached an advanced state of dissolution, rosettes were no longer formed.

Modification of mouse immune responses against allogeneic tumor by pretreatment of antigen with mitomycin C or X-irradiation.

Treatment of P815 mastocytoma cells with mitomycin C or X-irradiation prior to their inoculation into an allogeneic host resulted in a shift in the appearance of the peak of the T-killer cell population from day 10 to day 6. This finding is discussed in relation to the caution that must be exerted in extrapolating data obtained in studies in vitro using one-way mixed lymphocyte cultures to in vivo model systems involving proliferating tumor cells as immunogens.