Organochlorine Contaminants of Wintering Ducks Foraging on Detroit River Sediments

Organochlorine analysis was performed on carcasses of 13 diving ducks from a 1981 wintering population that foraged on contaminated sediments in the lower Detroit River. Mean total PCB concentrations were 10 mg/kg for seven lesser scaups (Aythya affinis), 11 mg/kg for three greater scaups (A. marila), and 7.6 mg/kg for three goldeneyes (Bucephala clangula). Highest mean levels of other residues were measured for hexachlorobenzene (1.7 mg/kg) in goldeneyes, and transnonachlor (0.33 mg/kg) and 4,4’-DDE (1.3 mg/kg) in greater scaup. Quantitative analysis of 72 PCB congeners also was applied to water, seston, sediment, benthie oligochaetes, and carp from the same site. Principal congeners in most of the samples included some of the more toxic and persistent PCBs. Results of a multivariate analysis indicated that ratios of more conservative to less conservative PCBs did not vary significantly among ducks (α = .05), but differed from those in carp, oligochaetes, and sediment. For the February through March period of fat mobilization, concentrations of total PCB in lipid were inversely correlated with percent lipid (r = 0.76) in ducks. The percentage of conservative PCBs increased slightly. The distribution and partitioning of organochlorines, including toxic PCB congeners, varied considerably within this water column-sediment-fauna ecosystem. Estimates of toxic exposure based on total PCB values may be unreliable.     

Electrostatic polymer processing of isotactic poly(4-methyl-1-pentene) fibrous membrane

Isotactic poly(4-methyl-1-pentene) (P4M1P) is a widely used polymer in industrial applications and specifically, in medical products. Producing micro- or nanofibers would expand the usefulness of P4M1P to a broad range of medical applications. The choice and quality of solvent for the solution used for electrospinning can have a dramatic effect on the spinnability of fibers and on their morphological appearance. In this study, four solvent systems: cyclohexane, cyclohexane/acetone mixture, cyclohexane/dimethyl formamide (DMF) mixture and cyclohexane/acetone/DMF mixture have been investigated. As demonstrated by FE-SEM, electrospun fibers with different morphologies including round, twisted with a roughened texture, curled and twisted-ribbon shapes were formed. The fiber shape and morphology depended strongly on the type and amount of non-solvent used.     

Effects of order of presentation on perceptions of the counselor.

Attempted to determine whether the order in which 2 counselors were presented on videotape would affect ratings of their performances. 70 participants (63 women and 7 men) randomly assigned to 2 groups viewed and rated counseling interviews conducted by C. Rogers and E. L. Shostrom. Groups differed only in the order of presentation of counselors. The resulting 2?×?2 split-plot factorial design had 1 between-Ss factor (order of presentation) and 1 within-S factor (counselor). A multivariate analysis of variance (MANOVA) yielded a statistically significant interaction, indicating that the order in which counselors were evaluated significantly affected the magnitude of ratings of their performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preweaning growth traits for Senepol, Hereford, and reciprocal crossbred calves and feedlot performance and carcass characteristics of steers

We conducted a multiyear study in two phases to determine preweaning performance traits of Senepol (S x S), Hereford (H x H), and reciprocal (S x H and H x S) F1 crossbred calves and feedlot performance and carcass characteristics of steers. In Phase I, from 1985 to 1989, data from S x S (n = 194), H x H (n = 383), and S x H (n = 120) calves were used. Numbers of S x S cows were increased during Phase I so that data from H x S (n = 74) calves could be included in Phase II (1990 to 1992) in addition to S x S (n = 118), H x H (n = 130), and S x H (n = 56) calves. Also during Phase II, feedlot performance and carcass characteristics were determined for S x S (n = 30), H x H (n = 26), H x S (n = 36), and S x H (n = 26) steers. In Phase I, S x S calves had heavier (P < .01) birth weights and heavier (P < .01) 205-d adjusted weaning weights than H x H calves. Birth weights of S x H calves were heavier (P < .01) than the mean of the purebred calves, but 205-d adjusted weaning weights did not differ (P > .10). In phase II, direct heterosis was 3.5% for birth weight (P < .05) and 5.1% for 205-d adjusted weaning weight (P < .01). Senepol maternal breed effects were 1.9 kg for birth weight (P < .10) and 37.9 kg for 205-d adjusted weaning weight (P < .01). Levels of direct heterosis, Senepol maternal breed effects, and Hereford direct breed effects were significant for most feedlot performance traits of steer calves that were fed to a common end point. Breeds did not differ (P > .10) for USDA yield and quality grades, and direct heterosis was not significant for Warner-Bratzler shear force. These results demonstrate significant levels of heterosis in preweaning performance between S x S and H x H calves and in feedlot performance of steers. Levels of heterosis were smaller and nonsignificant for most carcass traits including meat tenderness, which did not differ between S x S and H x H steers in this study.     

Evaporative light scattering mass detection for high-performance liquid chromatographic analysis of sucrose polyester blends in cooking oils

A high-performance liquid chromatographic method is described to determine the sucrose polyester (SPE) content in seven blends of cooking oils. Four gel-permeation chromatography (GPC) columns were used in series with an evaporative light scattering mass detector to separate the SPE from the acylglycerols in the final chromatogram. The SPE fraction was collected off the GPC column and injected onto a reverse-phase C-18 column for quantitation with sucrose octaacetate as an internal standard and a gradient of nonaqueous solvents as mobile phase. The chromatograms were interference-free, with only two sharp peaks appearing. The standards were linear from 500 to 5000 μg/mL with a correlation coefficient of r=0.999. The mean percent recovery (n=9) and standard deviation were 102±6.7. The detector could detect amounts as low as 5 μg SPE.     

Brain mass estimation by head circumference and body mass methods in neonatal glycaemic modelling and control

Introduction

Hyperglycaemia is a common complication of stress and prematurity in extremely low-birth-weight infants. Model-based insulin therapy protocols have the ability to safely improve glycaemic control for this group. Estimating non-insulin-mediated brain glucose uptake by the central nervous system in these models is typically done using population-based body weight models, which may not be ideal.

Method

A head circumference-based model that separately treats small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) infants is compared to a body weight model in a retrospective analysis of 48 patients with a median birth weight of 750 g and median gestational age of 25 weeks. Estimated brain mass, model-based insulin sensitivity (S_I) profiles, and projected glycaemic control outcomes are investigated. SGA infants (5) are also analyzed as a separate cohort.

Results

Across the entire cohort, estimated brain mass deviated by a median 10% between models, with a per-patient median difference in S_I of 3.5%. For the SGA group, brain mass deviation was 42%, and per-patient S_I deviation 13.7%. In virtual trials, 87–93% of recommended insulin rates were equal or slightly reduced (Δ < 0.16 mU/h) under the head circumference method, while glycaemic control outcomes showed little change.

Conclusion

The results suggest that body weight methods are not as accurate as head circumference methods. Head circumference-based estimates may offer improved modelling accuracy and a small reduction in insulin administration, particularly for SGA infants.     

2,2′-oxo-1,1′-azobenzene: microbial transformation of rye (Secale cereale L.) allelochemical in field soils byAcinetobacter calcoaceticus: III

Acinetobacter calcoaceticus, a gram-negative bacterium isolated from field soil, was found to be responsible for the biotransformation of 2(3H)-benzoxazolinone (BOA) to 2,2-oxo-1,1-azobenzene (AZOB). Experiments were conducted to evaluate the transformation of BOA to AZOB by this microbe in sterile and nonsterile soil. Transformation studies with soils inoculated withA. calcoaceticus indicated that the production of AZOB increased linearly with the concentration of BOA in sterile soil and showed a quadratic trend in nonsterile soils. This also indicated that all soil types studied for the transformation experiments might containA. calcoaceticus capable of the conversion of benzoxazolinones.     

Effects of coralline lime on nutrient uptake and yield of field-grown sweet corn and peanuts in Oxidic soils of Western Samoa

Effects of coralline lime on yield and nutrient uptake by sweet corn (Zea mays saccharata Sturt.) and peanut (Arachis hypogea) were studied at three locations in Western Samoa. Coarse (0-10 mm) coralline material containing 31.1% Ca and 1.67% Mg was used as lime. There were two modes of application: band and broadcast, and three rates: 6, 12 and 18 ton ha^–1. In the highest rainfall location, marketable yields were increased by 250% for peanut and 160% for sweet corn by liming at 6 ton ha^–1, relative to the unamended control. Peanut yield increases were associated with reduced Mn toxicity and/or with Ca and Mg deficiency. Sweet corn was less susceptible to Mn toxicity, but more responsive to exchangeable Ca. The critical level of exchangeable Ca was found to be about 2.0 cmol(+)kg^–1. Applying lime to a band of 0.25-m wide did not reduce yield relative to broadcast. Soil cultivation caused the lime to spread over a wider band, diluting the applied calcium with a larger soil volume, suggesting that less than 6 ton ha^–1 broadcast coarse coralline lime could still be adequate for most Samoan soils.