Fatty acid composition of oil from exotic corn breeding materials

The fatty acid composition of corn oil can be altered to meet consumer demand for “healthful” fats. The first step in altering the oils is to survey existing corn breeding materials for fatty acid composition. The Latin American Maize Project (LAMP), an international program designed to evaluate the agronomic characteristics of maize accessions in Latin American and U.S. germplasm banks for future use, provides useful starting materials. LAMP was based on the cooperative efforts of 12 countries. In a two-stage evaluation, the project identified the highest-yielding open-pollinated top 20% of populations, then approximately the top 5% of those 20%. Twenty of the populations from four countries with temperate climates were randomly selected for fatty acid analysis. The populations were from United States, Chile, Argentina, and Uruguay. Fifty S₁ lines from each population were randomly chosen for analysis for a total of 1,000 genotypes sampled. Statistical differences in fatty acid composition were computed among the 20 populations and among the four countries. The findings showed a wide range of fatty acid profiles present in unadapted, elite corn breeding materials with ranges for each fatty acid as follows: palmitic acid, 6.3–18.2%; stearic acid, 0.9–4.5%; oleic acid, 18.5–46.1%; linoleic acid, 36.6–66.8%; linolenic acid, 0.0–2.0%; and arachidic acid, 0.0–1.4%. Several populations were significantly different from the others. Some lines had unusual fatty acid compositions, including one with 8.3% total saturates and another with 20.2% total saturates. This study shows that existing corn breeding materials could be used to produce high- and low-saturate oils, but other methods would probably be required to produce a high-oleic corn oil.     

Fatty acid composition of oil from adapted,elite corn breeding materials

The fatty acid composition of corn oil can be altered to meet consumer demands for “healthful” fats (i.e., lower saturates and higher monounsaturates). To this end, a survey of 418 corn hybrids and 98 corn inbreds grown in Iowa was done to determine the fatty acid composition of readily-available, adapted, elite corn breeding materials. These materials are those used in commercial hybrid production. Eighty-seven hybrids grown in France (18 of which also were grown in lowa) were analyzed to determine environmental influence on fatty acid content. The parents of the hybrids and the inbreds were classified in one of four heterotic groups: Lancaster, Stiff Stalk, non-Lancaster/non-Stiff Stalk, and Other.t-Tests and correlation analyses were performed with statistical significance accepted at a level ofP≤0.05. The findings showed a wide range of fatty acid profiles present in adapted, elite corn breeding materials with ranges for each fatty acid as follows: palmitic acid, 6.7–16.5%; palmitoleic acid, 0.0–1.2%; stearic acid, 0.7–6.6%; oleic acid, 16.2–43.8%; linoleic acid, 39.5–69.5%; linolenic acid, 0.0–3.1%; and arachidic acid, 0.0–1.0%. Small amounts of myristic acid, margaric acid, and gadoleic acid also were found. Three lines had total saturates of 9.1% or less. Thirty-six of thet-tests involving hybrids showed significant differences among heterotic groups. There were small but significant correlations among protein, starch and oil content and the amounts of several fatty acids. Results from the corn grown in France vs. lowa demonstrated a large environmental effect that overwhelmed the genetic differences among lines. This study shows that for some attributes, a breeding program involving adapted corn breeding materials might produce the desired oil. Other types of oil (such as high-oleic) would have to be produced in a different manner, for example, by a breeding program with exotic breeding materials.     

Preparation of nanocomposite alumina–Sn2Fe by mechanical alloying

Nanocomposites of Al₂O₃ and Sn₂Fe were prepared by ball milling alumina with elemental Sn and Fe. Samples were prepared with molar ratios of Al₂O₃ and Sn₂Fe of 1:1 and 2:1. Materials produced in this way have been characterized by X-ray diffraction techniques as well as ⁵⁷Fe Mössbauer effect spectroscopy as a function of milling time. The nanosized grains show a distribution of particle sizes along with some residual elemental components. Preliminary investigations of electrochemical cells indicate that these materials show promise as possible electrodes for Li-ion cells.     

Skew and internal consistency.

The effects of skew on the standardized item alpha were examined with Monte Carlo techniques. Alphas computed from normal variables were compared with alphas from lognormal variables, ranks, and skewed versus normal Likert-type variables. The extent and direction of skew were varied, as was the size of the population interitem correlation (rho), the number of items, and the number of categories for Likert-type variables. Because the average interitem correlation affects alpha and skew affects the average interitem correlation, the effect of skew on the average interitem correlation also was examined. Results indicated that skew decreased the average interitem correlation and produced small decreases in alpha that were largest when skew was large, rho was small, items were skewed in opposite directions, and there were fewer items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Meta-analysis and moderator variables: A cautionary note on transportability.

Despite the recent popularity of meta-analysis as a tool for summarizing empirical results across a number of studies, surprisingly little research has been conducted on the accuracy of these procedures under a variety of population conditions. Of concern in this study was the 90% credibility value (K. Pearlman et al, see record 1980-31533-001) advocated as a rule of thumb regarding the transportability of employment test validities. We investigated the ability of this meta-analytic rule to detect the presence of discretely defined moderator variables, that is, the ability of the rule to detect instances where transportability is inappropriate. An infinite sample size analysis and a mathematical proof demonstrated that the transportability rule may produce erroneous inferences at rates higher than expected. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of variance with ipsative measures.

Measures with more than 1 score per participant, when the total for each participant equals the same constant, are said to be ipsative. Ipsativity occurs when data are percentages, with each participant's total equal to 100%, or when data are ranks, with each participant's total equal to the sum of the ranks. When ipsative measures are analyzed with analysis of variance (ANOVA), certain sums of squares equal 0, and the average intercorrelation among measures is negative. These characteristics of ipsativity may result in violations of ANOVA assumptions, producing an inflated Type I error rate and affecting power. The purpose of this Monte Carlo study was to empirically examine the extent to which ANOVA is affected by ipsative data. Findings indicated that, with few exceptions, ANOVA worked quite well with ipsative data. Not only were Type I error rates well preserved, but power was nearly equivalent to that with nonipsative data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Knee position error detection in closed and open kinetic chain tasks during concurrent cognitive distraction

OBJECTIVES: To estimate the number of breast cancer deaths induced by low dose radiation in breast cancer screening programmes compared with numbers prevented. METHODS: A computer simulation model on the natural history of breast cancer was combined with a model from BEIR-V on induced breast cancer mortality from low levels of radiation. The improvement in prognosis resulting from screening was based on the results of the Swedish overview of the randomised screening trials for breast cancer and the performance of screening in the Netherlands. Different scenarios (ages and intervals) were used to explore the objectives. Sensitivity analyses were carried out for latency period, dose of mammography, sensitivity of the screening test, early detection by screening of induced breast tumours, and new 1996 risk estimates by Howe and McLaughlin. RESULTS: For a screening programme, age group 50-69, two year interval, 2 mGy per view, the balance between the number of deaths induced versus those prevented was favourable: 1:242. When screening is expanded to the age group 40-49 with a one or two year interval the results may be less favourable, that is, 1:66 and 1:97. According to these scenarios and with the Dutch scenario as reference, one breast cancer death from radiation may be expected to occur to save eight extra deaths from breast cancer. If screening was equally effective in young women as in women aged 50-69, the marginal value was 1:+/- 30. Assuming detection of induced cancers by screening could influence the ratios by about 30%, but did not substantially change the conclusions. The new risk estimates by Howe and McLaughlin resulted in five times to eight times favourable ratios breast cancer deaths induced to prevented. Besides age group of screening, dose of mammography is the other determinant of risk. CONCLUSIONS: For screening under the age of 50, the balance between the number of breast cancer deaths prevented by screening compared with the number induced by radiation seem less favourable. Credibility intervals were however wide, because of many uncertainties of radiation risk at very low doses.     

An efficient HBT/RTD oscillator for wireless applications

In this paper, we introduce a novel HBT/RTD oscillator suitable for monolithic integration and efficient low power/battery-operated applications. Implementation of a circuit prototype was accomplished by configuring an InP-based monolithic HBT/RTD chip with a gold wire bond inductor in a hybrid microwave package. For an output frequency of 5.8 GHz, the circuit draws a current of 15.5 mA from a 1.5 V supply and generates an output power of +3.13 dBm, for an efficiency of 8.84%