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  • 2003  (69)
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  • 2003  (69)
  • 1
    Language: English
    In: Environmental Toxicology and Chemistry, May 2003, Vol.22(5), pp.1172-1176
    Description: In situ testing represents an alternative to conventional laboratory toxicity testing of field samples. Juvenile (Crustacea: Amphipoda) were exposed in situ in two rivers downstream of fruit orchard areas in the Western Cape, South Africa. Exposure took place during six time intervals (3–7 d), of which three represented the first rainfall‐induced edge‐of‐field runoff events of the wet season, which was about two months after the last pesticide application. Survival rates were significantly reduced (35–70%) during runoff events 1 and 2 at both sites. No difference was observed from the respective no‐runoff survival rate (〉90%) during event 3. Peak levels of total insecticides (azinphosmethyl, chlorpyrifos, endosulfan, and prothiofos) in samples taken with water level‐triggered samplers during the runoff events were between 0.03 and 0.26 μg/L in filtered water and between 305 and 870 μg/kg in suspended particles during runoff events 1 and 2 and only up to 0.01 μg/L and 101 μg/kg during event 3. Total suspended solids (TSS) varied between 400 and 700 mg/L during all three runoff events but never exceeded 65 mg/L during no‐runoff time intervals. A laboratory experiment revealed that uncontaminated TSS levels of 1,500 mg/L during a 7‐d exposure caused insignificant mortality (〈2.5%) in No acute toxicity was observed in standard 48‐h toxicity tests with juvenile using the filtered water samples taken during runoff and no‐runoff conditions. It is concluded that the observed mortalities were caused by particle‐associated pesticides and that the present amphipod in situ bioassay represents a sound and sensitive tool to detect runoff‐related insecticide effects under field conditions.
    Keywords: Amphipod ; Field Study ; In Situ Testing ; Insecticides ; Runoff
    ISSN: 0730-7268
    E-ISSN: 1552-8618
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  • 2
    Language: English
    In: Physical review letters, 05 September 2003, Vol.91(10), pp.103901
    Description: In this Letter we present a simple and novel theoretical approach for modeling the intensity distribution from an arbitrarily shaped turbid volume in a noncontact geometry by considering diffuse light propagation in free space. This theory is validated with experiments for a diffusive volume of known geometry in a noncontact situation, both with and without the presence of an embedded absorber. The implications of this new formulation in the context of optical tomography in turbid media are discussed.
    Keywords: Models, Theoretical ; Optics and Photonics ; Image Processing, Computer-Assisted -- Methods
    ISSN: 0031-9007
    E-ISSN: 10797114
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  • 3
    Language: English
    In: Chemosphere, 2003, Vol.51(6), pp.509-513
    Description: A water-sampling device to monitor the quality of water periodically and temporarily flowing out of concrete tubes, sewers or channels is described. It inexpensively and easily enables a qualitative characterization of contamination via these point-source entry routes. The water sampler can be reverse engineered with different sizes and materials, once installed needs no maintenance, passively samples the first surge, and the emptying procedure is short. In an agricultural catchment area in Germany we monitored an emergency overflow of a sewage sewer, an outlet of a rainwater sewer and two small drainage channels as input sources to a small stream. Seven inflow events were analysed for 20 pesticide agents (insecticides, fungicides and herbicides). All three entry routes were remarkably contaminated. We found parathion-ethyl concentrations of 0.3 mu g l super(-1), diuron up to 17.3 mu g l super(-1), ethofumesate up to 51.1 mu g l super(-1), metamitron up to 92 mu g l super(-1) and prosulfocarb up to 130 mu g l super(-1).
    Keywords: Herbicides ; Fungicides ; Insecticides ; Small Streams ; Point Sources ; Sewage Plant ; Rainwater Sewer ; Pipes ; Chemistry ; Ecology
    ISSN: 0045-6535
    E-ISSN: 1879-1298
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  • 4
    Language: English
    In: Optics letters, 15 September 2003, Vol.28(18), pp.1701-3
    Description: Optical tomography of turbid media has so far been limited by systems that require fixed geometries or measurements employing fibers. We present a system that records noncontact optical measurements from diffuse media of arbitrary shapes and retrieves the three-dimensional surface information of the diffuse medium. We further present a novel method of combining this composite data set and obtain accurate fluorescence reconstructions. This approach offers significant experimental simplicity and yields high-information-content datasets. The performance of this novel tomographic approach is demonstrated with experimental reconstructions of phantoms.
    Keywords: Models, Theoretical ; Optics and Photonics ; Tomography
    ISSN: 0146-9592
    E-ISSN: 15394794
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  • 5
    Language: English
    In: Environmental Toxicology and Chemistry, March 2003, Vol.22(3), pp.494-500
    Description: Runoff and spray drift are important sources of nonpoint pesticide pollution in surface waters, but few studies have directly compared these routes of input in an exposure assessment scenario. To this end, a runoff formula suggested by the Organization for Economic and Cooperative Development (Paris, France) and basic drift values (95th percentiles) were integrated into a geographical information system (GIS) to predict runoff and spray drift‐related loading of azinphosmethyl (AZP) in the Lourens River (LR), South Africa. The GIS‐integrated calculations were first validated in the tributaries of the river, where measured loads were well predicted for both runoff ( = 0.95; 〈 0.0001; = 9) and spray drift ( = 0.96; = 0.0006; = 8). Through extrapolation to the catchment scale containing 400 ha of orchards, the GIS‐integrated calculations predicted similar loads of AZP as measured in the Lourens River mainstream for six runoff (between a factor of 1.03 and 1.86 lower) and six spray drift (between a factor of 1.1 and 2.4 higher) events. Mean measured loads per event were significantly ( = 0.004) higher for runoff (27.8 ± 19.1 g) than for spray drift (0.69 ± 0.32 g). Based on long‐term meteorological data and average application regimes, runoff leads to a higher annual load (47.6 g) than spray drift (5.5 g) in the Lourens River. Runoff is clearly a more important source of nonpoint pollution in the studied catchment, and mitigation strategies should focus first on addressing this aspect on a catchment scale and second on addressing problem areas on a subcatchment scale.
    Keywords: Exposure Assessment ; Geographical Information System ; Insecticides ; Runoff ; Spray Drift
    ISSN: 0730-7268
    E-ISSN: 1552-8618
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  • 6
    Language: English
    In: Ecological Indicators, 2003, Vol.2(4), pp.391-401
    Description: The development and the evaluation of a biological indicator system for pesticide pollution in streams are presented. For small headwater streams with an agricultural catchment area, the expert system LIMPACT estimates the pesticide contamination according to the four classes: Not Detected (ND), Low (L), Moderate (M) and High (H) contamination without any specification of the chemical agents. The input parameters are the abundance data of benthic macroinvertebrate taxa within four time frames in a year (March/April, May/June, July/August, September/October) and nine basic water-quality and morphological parameters. The heuristic knowledge base was developed with the shell-kit D3 and contains 921 diagnostic rules with scores either to establish or to de-establish a diagnosis. The 418 rules had less than three symptoms, and only 47 rules had more than four symptoms in their rule condition. We differentiate between positive indicator (PI) taxa, which indicate contamination by high abundance values and positive abundance dynamics, and negative indicator (NI) taxa, a high abundance of which rules out contamination and indicates an uncontaminated site. We analysed 39 taxa and found 13 positive and 24 negative indicators. The database comprises 157 investigations per stream and year with rainfall event- controlled pesticide sampling and repeated benthic sampling as described in Part 1 [Ecol. Indicators, this issue]. For the evaluation of LIMPACT, we used the same cases. The correct class for the 157 investigations per stream and year is established by LIMPACT in 66.7-85.5% of the cases, with better results for uncontaminated sites. The overall alpha error probability (false positive) is 9.6% while the beta error probability (false negative) varied between 0 and 8% depending on the contamination class. If each stream is considered only once in the system (n=104), the correct diagnosis is established by LIMPACT in 51.9- 88.6% of the cases. In most of the remaining cases no diagnosis is established instead of a wrong one.
    Keywords: Ecological Indicator ; Pesticide Contamination ; Small Streams ; Heuristic Knowledge Base ; Model ; Environmental Sciences
    ISSN: 1470-160X
    E-ISSN: 1872-7034
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  • 7
    Language: German
    In: Umweltwissenschaften und Schadstoff-Forschung, 2003, Vol.15(3), pp.152-156
    Description: Die Entwicklung, der Aufbau und die Evaluierung eines biologischen Indikatorsystems für die Pflanzenschutzmittel-Belastung in kleinen Fließgewässern wird vorgestellt. In Fließgewässern mit landwirtschaftlichem Einzugsgebiet stuft das Expertensystem LIMPACT die Belastung in vier Klassen ‘unbelastet/nicht nachgewiesen’, ‘gering’, ‘mittel’ und ‘hoch’ belastet ein. Eingangsdaten sind dabei die Abundanzdaten der benthischen Makroinvertebraten-Fauna zu vier Terminen im Jahresverlauf (März/April; Mai/Juni; Juli/August; September/Oktober) und neun physikalisch-chemische bzw. morphologische Fließgewässerparameter. Die Wissenbasis wurde mit dem Shellbaukasten D3 aufgebaut und enthält 921 Regeln zum etablieren oder de-etablieren einer Bewertungsklasse. Es wurden 39 Arten und Taxa analysiert und dabei 13 positive und 24 negative Indikatorspezies definiert. Positive Indikatorarten zeigen eine hohe Belastung durch hohe Abundanzen an, während negative Indikatorarten durch eine hohe Abundanz eine Belastung ausschließen und unbelastete Bäche anzeigen. Die Datenbasis enthielt 157 jährliche Untersuchungen und wurde auch zur Evaluierung eingesetzt. Die korrekte Klassifikationsrate liegt bei 66,7–85,5% der Fälle. Die meisten verbleibenden Fällen werden nicht falsch eingestuft, sondern infolge der konservativen Bewertung bei geringer Datengrundlage nicht klassifiziert. The development and the evaluation of a biological indicator system for pesticide pollution in streams are presented. For small headwater streams with an agricultural catchment area, the expert system LIMPACT estimates the pesticide contamination according to the four classes of Not Detected, Low, Moderate and High contamination without any specification of the chemical agents. The input parameters are the abundance data of benthic macroinvertebrate taxa within four time frames in a year (March/April; May/June; July/August; September/October) and 9 basic water-quality and morphological parameters. The heuristic knowledge base was developed with the shell-kit D3 and contains diagnostic rules with scores to either establish or de-establish a contamination class. We differentiate between positive indicator taxa, which indicate contamination by high abundance values and positive abundance dynamics, and negative indicator taxa, a high abundance of which rules out contamination and indicates an uncontaminated site. We analysed 39 taxa and found 13 positive and 24 negative indicators. The database is comprised of 157 investigations per stream and year. For the evaluation of LIMPACT, we used the same cases. The correct diagnosis for the 157 investigations per stream and year is established by LIMPACT in 66.7 to 85.5% of the cases, with better results for uncontaminated sites. In most of the remaining cases no diagnosis is established instead of an incorrect one.
    Keywords: Agriculture ; biological indicator ; fungizides ; herbizides ; heuristic knowledge base ; insectizides ; LIMPACT (Limnology Impact) ; non-point sources ; pesticides ; runoff ; streams, pesticide contamination
    ISSN: 0934-3504
    E-ISSN: 1865-5084
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  • 8
    In: Transplantation, 2003, Vol.76(3), pp.615-618
    Description: Acute rejection resistant to established immunosuppressive rescue protocols remains the most prominent risk factor after intestinal transplantation. In two patients presenting with steroid-resistant severe acute cellular rejection 9 months and 2 years after intestinal transplantation, complete resolution was not achieved despite 5 and 10 days of OKT3 treatment, respectively, and high-dose triple baseline immunosuppression with tacrolimus, rapamycin, and steroids. There was a dissociated course of rejection with persistent moderate to severe rejection in the terminal portion of the graft despite complete recovery from rejection in the proximal parts. Both patients were treated with four subsequent infusions of infliximab (3 mg/kg body weight), a chimeric anti-tumor necrosis factor-α antibody. There was an immediate response regarding macroscopic appearance, graft histology, and clinical symptoms. Both patients recovered. In conclusion, infliximab has proven to be an effective rescue therapy in a selected group of patients with steroid and OKT3 refractory severe acute rejection after intestinal transplantation.
    Keywords: Immunosuppressive Agents ; Intestine ; Transplantation ; Monoclonal Antibodies ; Graft Rejection ; Steroid Hormones ; Infliximab ; Okt3 ; Clinical ; Other ; Man ; Okt3 ; Infliximab ; Man;
    ISSN: 0041-1337
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  • 9
    Language: English
    In: Environmental science & technology, 15 May 2003, Vol.37(10), pp.2139-44
    Description: Our knowledge about the effectiveness of constructed wetlands in retaining agricultural nonpoint-source pesticide pollution is limited. A 0.44-ha vegetated wetland built along a tributary of the Lourens River, Western Cape, South Africa, was studied to ascertain the retention, fate, and effects of spray drift-borne azinphos-methyl (AZP). Composite water samples taken at the inlet and outlet during five spray drift trials in summer 2000 and 2001 revealed an overall reduction of AZP levels by 90 +/- 1% and a retention of AZP mass by 61 +/- 5%. Samples were collected at the inlet outlet, and four platforms within the wetland to determine the fate and effect of AZP in the wetland after direct spray drift deposition in the tributary 200 m upstream of the inlet. Peak concentrations of AZP decreased, and the duration of exposure increased from inlet (0.73 microg/L; 9 h) via platforms 1 and 4 to outlet (0.08 microg/L; 16 h). AZP sorbed to plants or plant surfaces, leading to a peak concentration of 6.8 microg/kg dw. The living plant biomass accounted for 10.5% of the AZP mass initially retained in the wetland, indicating processes such as volatilization, photolysis, hydrolysis, or metabolic degradation as being very important AZP was not detected in sediments. Water samples taken along two 10-m transects situated perpendicular to the shore indicated a homogeneous horizontal distribution of the pesticide: 0.23 +/- 0.02 and 0.14 +/- 0.04 microg/L (n = 5), respectively. Both Copepoda (p = 0.019) and Cladocere (p = 0.027) decreased significantly 6 h postdeposition and remained at reduced densities for at least 7 d. In parallel, the chlorophyll a concentration showed an increase, although not significant, within 6 h of spray deposition. The study highlights the potential of constructed wetlands as a risk-mitigation strategy for spray drift-related pesticide pollution.
    Keywords: Azinphosmethyl -- Analysis ; Crustacea -- Metabolism ; Pesticide Residues -- Analysis ; Plants -- Metabolism ; Waste Disposal, Fluid -- Methods ; Water Pollutants, Chemical -- Analysis
    ISSN: 0013-936X
    E-ISSN: 15205851
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  • 10
    In: American Journal of Transplantation, August 2003, Vol.3(8), pp.1033-1035
    Description: A 50‐year‐old recipient of an intestinal and coecal graft with sudden onset of abdominal distention and pain, lack of bowel movements, and vomiting after closure of the diagnostic ostomy 7 months after transplantation is reported. A plain abdominal radiograph revealed pneumatosis intestinalis. An angiography excluded obstruction of large vessels, however, with absent microcirculation of the intestine. Upper gastrointestinal endoscopy showed extensive ulcerative enteritis with several spontaneous perforations. The patient underwent exploration demonstrating a nonviable intestine. The entire necrotic intestine was removed. Vascular thrombosis was excluded. Clinical data, and macroscopic and histologic features of the intestinal graft were diagnostic for necrotizing enterocolitis (NEC). Though there has been evidence for the occurrence of NEC not only in premature infants but even in older infants, children and adolescents, the presented case is, to our knowledge, the first report of NEC as etiology of late graft loss after intestinal transplantation in an adult recipient.
    Keywords: Intestinal Transplantation ; Necrotizing Enterocolitis
    ISSN: 1600-6135
    E-ISSN: 1600-6143
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