Isolation of methylcis,cis-5, 13-docosadienoate fromLimnanthes douglasii oil

Methylcis,cis-5,13-docosadienoate has been isolated from the mixed methyl esters of the fatty acid moiety ofLimnanthes douglasii oil by a combination of low temperature fractional crystallization and fractionation of mercuric acetate adducts. The methyl ester and its free acid have been characterized. So. Util. Res. Dev. Div., ARS, USDA.     

Isoenzymes of lipoxidase

A polyacrylamide disc gel electrophoretic technique is described for studying isoenzymes or multiple molecular forms of lipoxidase in extracts of fresh green peas, pea seeds, wheat, fresh green beans and green bean seeds. After electrophoresis, gels containing starch were incubated with linoleic acid. Hydroperoxide bands were visualized by treating the gel with acidic potassium iodide. Staining specificity was established using the following criteria. Activity was absent when extracts or gels were boiled and when linoelaidic and oleic acids were used as substrates. Cyanide did not inhibit staining, whereas α-tocopherol, hydroquinone and nordihydroguaiaretic acid did. Prevention of the appearance of artifactual bands was attempted by: pre-electrophoresis of the gels; electrophoresis in the presence of thioglycollic acid; elimination of the large pore gel; pH adjustment of the plant extracts; and extraction of extract solids with lipid solvents. Gel patterns indicated two to three lipoxidase bands for fresh green peas and pea seeds, one to two bands for fresh green beans and green bean seeds, and four bands for wheat.     

Epoxidized jojoba oil as a stabilizer for vinyl chloride containing plastics

Summary Epoxidized jojoba oil has been evaluated as a light and heat stabilizer for vinyl chloride containing plastics and its properties, intercompared with those of other epoxides representative of three major classes of oxirane stabilizers. The results obtained show that epoxidized jojoba oil is a satisfactory thermal and ultraviolet stabilizer for both TCP and DOP plasticized stocks and has no adverse effects on the plasticizer properties of these materials. In general, epoxidized jojoba oil was found to be equivalent to or, in some instances, superior to the other epoxides tested.     

An eclectic model of supervision: A developmental sequence of beginning psychotherapy students.

Suggests a supervision model that uses both individual and group formats and incorporates 3 foci: facilitation of personal growth and awareness, acquisition of practical skills, and mastery of cognitive and theoretical knowledge. The initial experiences and needs of beginning psychotherapy students are used to illustrate this model. The trainees' needs are divided into 3 stages: role definition, skill acquisition, and practice solidification and evaluation. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Ambient Horn: designing a novel audio-based learning experience

The Ambient Horn is a novel handheld device designed to support children learning about habitat distributions and interdependencies in an outdoor woodland environment. The horn was designed to emit non-speech audio sounds representing ecological processes. Both symbolic and arbitrary mappings were used to represent the processes. The sounds are triggered in response to the childrens location in certain parts of the woodland. A main objective was to provoke children into interpreting and reflecting upon the significance of the sounds in the context in which they occur. Our study of the horn being used showed the sounds to be provocative, generating much discussion about what they signified in relation to what the children saw in the woodland. In addition, the children appropriated the horn in creative ways, trying to scoop up new sounds as they walked in different parts of the woodland.     

Spectroelectrochemical sensing based on multimode selectivity simultaneously achievable in a single device. 17. Improvement in detection limits using ultrathin perfluorosulfonated ionomer films in conjunction with continuous sample flow

We report herein an attenuated total reflectance (ATR) absorbance-based spectroelectrochemical sensor for tris(2,2'-bipyridyl)ruthenium(II) ion [Ru(bpy)(3)(2+)] that employs ultrathin (24-50 nm) Nafion films as the charge-selective layer. This film serves to sequester and preconcentrate the analyte at the optically transparent electrode surface such that it can be efficiently detected optically via electrochemical modulation. Our studies indicate that use of ultrathin films in tandem with continuous flow of sample solution through the cell compartment leads to a 100-500-fold enhancement in detection limit (10 nM) compared to earlier absorbance-based spectroelectrochemical sensors ( approximately 1-5 microM); markedly shorter analysis times also result. We report the dependence of the measured absorbance on sample flow rate and Nafion film thickness, and also provide calibration curves that illustrate the linear range and detection limits of the sensor using a 24 nm film at a constant sample flow rate of 0.07 mL/min.     

Picogram per liter level determination of estrogens in natural waters and waterworks by a fully automated on-line solid-phase extraction-liquid chromatography-electrospray tandem mass spectrometry method

The present work describes a novel, fully automated method, based on on-line solid-phase extraction-liquid chromatography-electrospray tandem mass spectrometry (SPE-LC-ESI-MS-MS), which allows the unequivocal identification and quantification of the most environmentally relevant estrogens (estradiol, estrone, estriol, estradiol-17-glucuronide, estradiol-17-acetate, estrone-3-sulfate, ethynyl estradiol, diethylstilbestrol) in natural and treated waters at levels well below those of concern (limits of quantification between 0.02 and 1.02 ng/L). The method is highly precise, with relative standard deviations varying between 1.43 and 3.89%, and accurate (recovery percentages >74 %). This method was used to track the presence and fate of the target compounds in a waterworks and to evaluate the removal efficiency of the treatment processes applied. Only estrone and estrone-3-sulfate were detected in the river water used as source (at 0.68 and 0.33 ng/L, respectively). After progressive removal through the various treatment steps, none of them were detected in the finished drinking water. In addition to selectivity, sensitivity, repeatability, and automation (up to 15 samples plus 6 calibration solutions and 1 blank can be analyzed unattended), this technique offers fairly high throughput (analysis time per sample is 60 min), low time and solvent consumption, and ease of use.     

Pre-cooked corn flour intake and its contribution of iron and vitamin A in low income preschoolers

The objective of this study was to determine whether the addition of iron and vitamin A (VA) to corn flour, supplied through a national enrichment program since 1993, allows preschoolers to achieve an adequate intake of these nutrients. Data from the assessment of 196 children (4-6 year old) from Valencia, Venezuela is presented, including socio-demographic, anthropometric, anemia, VA deficiency (by conjunctival impression cytology (CIC) and serum retinol), and food intake. 92% of the children lived in poverty. 12% were below the norm for weight-for-height. 13% had anemia, 9% had VA deficiency according to CIC, and 0.5% according to serum retinol (< 0.70 mumol/L), 30% were at risk of VA deficiency (0.70-1.05 mmol/L). 17%, 37%, and 5% of the sample had an insufficient intake (< 80% of RDA) of energy, iron, and VA, respectively. When excluding from the analysis the amount of iron and VA from corn flour enrichment, an additional 38% and 10% of the sample showed deficient intakes of each nutrient, respectively. According to the weight-for-height indicator, iron intake was significantly lower in undernourished children (p < 0.05) than in those normal or above the norm; this was not so for VA. It is concluded that iron enrichment contributes to the improvement of the intake of this nutrient but is not enough to provide an adequate amount of it; and that the addition of VA does not seem to have an important effect on the diet of this age group.     

Reflectance FTIR and SEM characterization of poly[N-vinylcarbazole-co-methylmethacrylate] electrografted carbon fiber surface: current density effect

Electrografting of poly [N-vinylcarbazole-co-methylmethacrylate] onto high tenacity carbon fiber (TENAX HTA 5000) was carried out under preparative constant current electrolysis conditions by using anode and cathode as fiber towings. The surface morphology of the electrografted carbon fibers was determined by scanning electron microscopy (SEM). FTIR reflectance measurements (FTIR-ATR) were applied for the characterization of chemical composition on the electrografted thin film surface on carbon fiber. The efficiency of the electrocopolymerization on carbon fiber surfaces under preparative constant current electrolysis conditions were evaluated, i.e., current density (charge) vs. thickness, yield and morphology.