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This study summarizes 23 field trials (over six geographic locations, with each trial composed of a separate field site and an application event) for quantifying the postapplication volatilization of dicamba from fields treated with an array of dicamba-containing formulations and tank adjuvants at an application rate of 0.56 or 1.12 kg dicamba acid equivalents (a.e.) per hectare (0.5 or 1.0 lb dicamba a.e. per acre). The data span 3 years of testing over a range of locations, field types, and environmental conditions. The aerodynamic and the integrated horizontal flux methodologies were employed (and then averaged) for estimating the vertical flux from the field for periods extending to approximately 72 h post application. In all cases, the vertical flux peaked within 24 h of application and then decayed to much lower levels by day 3. Total volatile losses among all formulations and conditions ranged from 0.023 ± 0.003 to 0.302 ± 0.045% of the applied dicamba (median = 0.08%). Analysis of the recorded meteorological and soil conditions for each field trial failed to identify any single soil or weather parameter as a dominant driver of total volatile losses. Air concentrations of dicamba observed in the course of these trials were all below the no observed adverse effect concentration for conventional soybean plant height or yield, indicating that air concentrations directly above or outside of the dicamba-treated area would not cause a reduction in plant height or yield of conventional soybean.

A surface drinking water monitoring program for four corn (Zea mays L.) herbicides was conducted during 1995-2001. Stratified random sampling was used to select 175 community water systems (CWSs) within a 12-state area, with an emphasis on the most vulnerable sites, based on corn intensity and watershed size. Finished drinking water was monitored at all sites, and raw water was monitored at many sites using activated carbon, which was shown capable of removing herbicides and their degradates from drinking water. Samples were collected biweekly from mid-March through the end of August, and twice during the off-season. The analytical method had a detection limit of 0.05 microg L(-1) for alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)-acetamide] and 0.03 microg L(-1) for acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)-acetamide], atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine], and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)-acetamide]. Of the 16528 drinking water samples analyzed, acetochlor, alachlor, atrazine, and metolachlor were detected in 19, 7, 87, and 53% of the samples, respectively. During 1999-2001, samples were also analyzed for the presence of six major degradates of the chloroacetanilide herbicides, which were detected more frequently than their parent compounds, despite having higher detection limits of 0.1 to 0.2 microg L(-1). Overall detection frequencies were correlated with product use and environmental fate characteristics. Reservoirs were particularly vulnerable to atrazine, which exceeded its 3 microg L(-1) maximum contaminant level at 25 such sites during 1995-1999. Acetochlor annualized mean concentrations (AMCs) did not exceed its mitigation trigger (2 microg L(-1)) at any site, and comparisons of observed levels with standard measures of human and ecological hazards indicate that it poses no significant risk to human health or the environment.

The fate and toxicity of a polyethoxylated tallowamine (POEA) surfactant system, MON 0818, was evaluated in water–sediment microcosms during a 4-d laboratory study. A surfactant solution of 8 mg l−1 nominal concentration was added to each of nine 72-l aquaria with or without a 3-cm layer of one of two natural sediments (total organic carbon (TOC) 1.5% or 3.0%). Control well water was added to each of nine additional 72-l aquaria with or without sediment. Water samples were collected from the microcosms after 2, 6, 24, 48, 72, and 96 h of aging to conduct 48-h toxicity tests with Daphnia magna and to determine surfactant concentrations. Elevated mortality of D. magna (43–83%) was observed in overlying water sampled from water-only microcosms throughout the 96-h aging period, whereas elevated mortality (23–97%) was only observed in overlying water sampled from water–sediment microcosms during the first 24 h of aging. Measured concentrations of MON 0818 in water-only microcosms remained relatively constant (4–6 mg l−1) during the 96-h period, whereas the concentrations in overlying water from microcosms containing either of the two types of sediment dissipated rapidly, with half-lives of 13 h in the 3.0% TOC sediment and 18 h in the 1.5% TOC sediment. Both toxicity and the concentration of MON 0818 in overlying water decreased more rapidly in microcosms containing sediment with the higher percent TOC and clay and with a higher microbial biomass. Mortality of D. magna was significantly correlated with surfactant concentrations in the overlying water. These results indicate that the toxicity of the POEA surfactant in water rapidly declines in the presence of sediment due to a reduction in the surfactant concentration in the overlying water above the sediment.

Herbicides entering the aquatic environment by spray drift, run-off and leaching to field drains may cause adverse effects on non-target aquatic vegetation. The potential for such effects has typically been evaluated from tests with floating, monocotyledonous Lemna sp. However, concern has been expressed as to whether this species could be used to indicate potential effects on other vegetation types, particularly rooted, submerged, emergent or dicotyledonous species. In 1997, the Centre for Aquatic Plant Management undertook development of new tests based on the additional species, Glyceria maxima (Hartm) Holmb, Lagarosiphon major (Ridl) Moss and Myriophyllum spicatum L. The resulting methodology was used to assess the effects of the sulfonylurea herbicide, sulfosulfuron on these species. Data presented here demonstrate that exposure to initial sulfosulfuron concentrations of 3.33 µg litre−1 for up to 21 days was tolerated by these species and that adverse effects were observed only when plants were exposed to initial concentrations of 3.33 and 10 µg litre−1 for 70 days. As the occurrence of such high initial concentrations for long periods is unlikely in the aquatic environment, sulfosulfuron is not expected to have adverse effects on the growth of these species. This study has also demonstrated that G maxima, L major and M spicatum grown in small outdoor tanks can be used successfully to assess the effects of crop-protection products on non-target aquatic flora. © 2003 Society of Chemical Industry

Thiazopyr labeled with 13C/14C was found to be rapidly metabolized and eliminated by laying hens dosed orally for four consecutive days at either 1.3 or 10.4 mg/day. Over 90% of the total radioactive dose appeared in the excreta within 22 h after the final dose at both levels. Tissue residues were very low in the muscle and egg white (0.004−0.01 ppm) with somewhat higher levels observed for the liver, abdominal fat, skin with fat, egg yolk, and kidney (0.047−0.298 ppm). The most abundant tissue metabolite was a nitrile ester resulting from the breakdown of the thiazoline ring of thiazopyr. A carboxylic acid metabolite found in the liver and excreta was shown to arise from oxidation at C-3 of the isobutyl side chain of the nitrile ester. In vitro liver homogenate studies demonstrated the presence of similar metabolic pathways in hens, goats, and rats, although the levels of individual metabolites varied. Keywords: Thiazopyr; hens; metabolites; MS; NMR

This paper presents experiences of energy efficiency engineering for decision support purposes in the context of seaport logistics and urban planning activities. The objective of these entrepreneurial research activities is to enhance the sustainability of human activities and resilience of decisions using optimization and simulation tools.

L'hydrochimie particuliere des eaux carbogazeuses, naturellement tres instables, implique des procedes d'exploitation specifiques. C'est la connaissance fine de leurs comportements thermodynamiques et geochimiques, par des mesures, analyses, etudes et modelisations qui permet d'acquerir les donnees essentielles au dimensionnement des equipements de production, transport, traitement et stockage, puis d'embouteillage. Apres quelques generalites sur ces ressources, les repercussions theoriques et appliquees de ces contraintes naturelles sont presentees et mettent en evidence les aspects diphasiques des ecoulements, la gestion necessaire des depots, du gaz et les traitements appropries. Le cas concret de Montrond-les-Bains (Forez) illustre la problematique generale

The effectiveness of regulatory non-target plant testing using crop species to predict the phytotoxicicity of herbicides to non-crop species was evaluated for eleven herbicides. These herbicides were representative of eight chemical classes and six modes of action. Data for non-crop plants from pre-emergence and post-emergence efficacy screening studies were compared with those for the most sensitive crop species defined by regulatory tests conducted to meet US EPA requirements. Testing under pre-emergence conditions for ten compounds indicated that for five of the compounds (K-815910, trifluralin, pyridyloxy A, pyridyloxy B and cyanazine), the most sensitive crop species was more sensitive than all the non-crop species evaluated. For metsulfuron-methyl, chlorimuron-ethyl, hexazinone and bromacil, only one of the non-crop species evaluated was more sensitive than the most sensitive crop species from regulatory tests. Data for the tenth compound, chloroacetamide, showed that four of 32 non-crop species tested in efficacy screens had at least one rate at which greater visual effects were observed than were observed for the most sensitive crop response in a regulatory test. The results of post-emergence exposure comparisons for five of the compounds (pyridyloxy A, cloransulam-methyl, chlorimuron-ethyl, cyanazine and hexazinone) indicated that the most sensitive crop species were more sensitive than all the non-crop species evaluated. Data for pyridyloxy B, metsulfuron-methyl and bromacil indicated that only one of the non-crop species evaluated was more sensitive than the most sensitive crop species. For trifluralin, three of the eight non-crop species were more sensitive than the most sensitive crop species. Data for K-815910 indicated that four of the fourteen non-crop species tested were marginally more sensitive than the most sensitive crop, but were within the same range of sensitivity. These results indicate that the current regulatory test batteries and methods using crop species effectively provide suitable sensitive indicator plants for the eleven diverse herbicides evaluated. This comparison indicates that crop species sensitivity to test substances is likely to be representative of non-crop herbaceous species response, regardless of chemical class, mode of action and magnitude or route of exposure.

A procedure is described for selection of temperature-sensitive mutants affecting fatty-acid synthesis based upon radiation suicide of wild-type organisms by tritiated acetate selectively incorporated into fatty acids. At 37°, two of the mutants extensively incorporate fatty-acid supplements provided in the medium, and grow for extended periods only when a trans -unsaturated or a combination of saturated and cis -unsaturated fatty acids is available. In vivo fatty-acid synthesis, measured by [ 14 C]acetate incorporation, is temperature-sensitive in these strains relative to protein synthesis and other non-lipid macromolecular syntheses using acetate. The biochemical nature of these mutations has not been identified.

The preparation of sheep red blood cells (SRBC) which have been sensitized with the haptens azobenzenearsonate, phosphorylcholine and azophenyltrimethylammonium, and are suitable for use in a plaque-forming cell assay, is described. Each hapten is first coupled to a phenolic imidoester (methyl-p-hydroxybenzimidate) and the substituted imidoesters are employed to prepare target SRBC. Details are presented concerning synthesis and purification of the imidoesters, as well as conditions for coupling to SRBC. The hapten-SRBC prepared by this method are very stable and offer significant advantages over other procedures for coupling these haptens to red blood cells.

The present study evaluates the unsaturated fatty acid requirement in Escherichia coli. A derivative of a double mutant defective both in unsaturated fatty acid biosynthesis and in fatty acid degradation has been selected which grows equally well on anteisopentadecanoate ( 12-Me-14:0 ) or cis-Δ 9 - octadecenoate ( cis-δ 9 -18:1 ). When this strain is grown for many generations on 12-Me-14:0 , there is extensive incorporation of this analogue into the membrane phospholipid and essentially no detectable unsaturated fatty acids residues in any lipid-containing structures of the cell envelope. Secondly, as the maximal growth temperature of E. coli is approached, the minimum content of unsaturated fatty acid required by this strain for growth decreases to a few percent and is associated with the appearance of substantial amounts of 12:0 (8%) and 14:0 (50%) in the phospholipid. These experiments demonstrate that the cis unsaturated fatty acids of E. coli phospholipids can be replaced by residues which possess no special electronic configuration. Hence, the unsaturated fatty acids do not participate in specific interactions with other membrane components but serve a general role of controlling the packing of paraffin chains in the membrane bilayer.