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An oral dose of the organophosphate insecticide methamidophos was administered to six volunteers at the acceptable daily intake (ADI, 0.004 mg/kg). Urine was collected from the volunteers at timed intervals for 24 h post-exposure. Methamidophos itself was quantified in urine using liquid/liquid extraction and LC–MS-MS analysis (detection limit 7 nmol/L/1 μg/L). Methamidophos exhibited a rapid elimination half-life of 1.1 h, (range 0.4–1.5 h). Mean metabolite levels found in 24 h total urine collections (normalised for a 70 kg volunteer) were 9.2 nmol/L (range 1.0–19.1). One volunteer was anomalous; excluding this result the range was 6.7–19.1 nmol/L, with a mean of 10.9 nmol/L. Individual urine samples collected during the first 24 h ranged from below the detection limit (ND) to 237 nmol/L. The mean dose recovery excreted as methamidophos in urine was 1.1% (range 0.04–1.71%). Three environmental studies have been reported in the literature with levels ranging from ND to 66 nmol/L. The number of positive results in all three studies was low (<1.5% of total samples analyzed). When compared with our results (ND – 237 nmol/L), the studies suggest general population exposures are within the ADI. However, the very short half-life makes determining intermittent environmental exposures difficult. [ABSTRACT FROM AUTHOR]

In order to study the potential swelling behavior of the ODS ferritic alloy MA957 at very high dpa levels, specimens were prepared from pressurized tubes that were unirradiated archives of tubes previously irradiated in FFTF to doses as high as 110 dpa. These unirradiated specimens were irradiated with 1.8 MeV Cr+ ions to doses ranging from 100 to 500 dpa and examined by transmission electron microscopy. No co-injection of helium or hydrogen was employed. It was shown that compared to several tempered ferritic/martensitic steels irradiated in the same facility, these tubes were rather resistant to void swelling, reaching a maximum value of only 4.5% at 500 dpa and 450 °C. In this fine-grained material, the distribution of swelling was strongly influenced by the presence of void denuded zones along the grain boundaries. [ABSTRACT FROM AUTHOR]

This article describes the derivation of system transfer functions, the analysis of this using Mathematica software, and the construction of Matlab/Simulink system models. Matlab/Simulink system models developed then needed to use a negative-acceleration feedback term, in order to produce a good stabilisation performance. Negative-acceleration minor feedback loops have been used for many years, in rate and position control systems, to modify system responses. However, there is some doubt that this method of modifying system responses had been adequately analysed. [ABSTRACT FROM AUTHOR]

Ternary austenitic model alloys were modified with 0.25?wt.% titanium and irradiated in the Fast Flux Test Reactor (FFTF) at dose rates ranging over more than two orders in magnitude. While lowering of the dose rate strongly increases swelling by shortening the incubation dose, the steady-state swelling rate is not affected by dose rate. Although titanium addition strongly alters the void microstructure, swelling at about 420°C does not change with titanium additions, but the sensitivity to dose rate is preserved. [ABSTRACT FROM AUTHOR]

Six-Month Feeding Study of Fenvalerate in Dogs. Parker, C. M., PICORILLO, V. J., KURTZ, S. L., GARNER, F. M., GARDINER, T. H., AND VAN GELDER, G. A. (1984) . 4, 577–586. Groups of six male and six female Beagle dogs were fed diets containing 0, 250, 500, or 1000 ppm fenvalerate for a period of 6 months. Prominent in-life observations related to treatment were emesis, head shaking, biting of the extremities, ataxia, and tremors. One high-dose male dog was sacrificed in extremis during the study period. Mean body weights of 1000-ppm female dogs were significantly lower than those of controls. Red blood cell counts and hematocrit and hemoglobin values in high-dose male and female dogs were significantly lower than those of controls at most sampling intervals. Serum cholesterol and alkaline phosphatase levels were also increased primarily in the high-dose group. Ophthalmic examination revealed changes in retinal vessel tortuosity in some mid- and high-dose dogs. Hepatic multifocal micro-granulomata were observed in control and treated dogs microscopically. These changes increased in incidence and severity with dose and were considered to be related to treatment Histiocytic cell infiltrate in mesenteric lymph nodes in some 500- and 1000-ppm female and 1000-ppm male dogs was the only other treatment-related microscopic effect. [ABSTRACT FROM PUBLISHER]