Oxidative stabilities of low-linolenate,high-stearate and common soybean oils

It is generally agreed that the high linolenate (18:3) content of soybean oil (SBO) contributes to its flavor instability. In this study, the oxidative stability of five SBO of various fatty acid (FA) compositions was compared by using peroxide values, conjugated dienoic acid values and sensory panel scores. Three of the oils were from common commercial varieties representing the range of 18:3 content normally found in SBO. The other two oils were from seed developed in a mutation breeding program. One of these oils from the line A5 had an 18:3 content of 3.5%, and the other from the line A6 had a stearate (18:0) content of 24%. Seed from the five soybean varieties was cold pressed, refined and deodorized without additives under laboratory conditions. Two oxidation experiments were conducted. In the first, the oils were stored at 28 C for 67 days. In the second, the oils were stored at 60 C for eight days. Sensory comparisons were done by using the AOCS Flavor Intensity Scale. The A5 and A6 oils were more stable than the commercial varieties as measured by chemical tests, but the sensory data were inconclusive. Oils with similar 18:3 contents did not have similar rates of oxidation. The differences between the oils were not as distinct in the 60 C test as in the 28 C test.     

Metal evaporation shadowing: A computer simulation

This paper addresses the question of what is the very best deposition that can be achieved by metal evaporation shadowing. It deals, therefore, with the resolution attainable in metal shadowed specimens. The analysis disregards interatomic attractions (nucleation, crystallite formation, decoration) and generates depositions solely on the basis of probabilities of vacant, single, and multiple atom landings at different points on a substrate. The treatment starts by showing that random number generation can be used to simulate reasonably the evaporation of metal atoms from a shadowing source and their deposit on a substrate. A Fortran program tabulates and displays these simulated atom landings. The analysis shows that one can never expect to obtain a perfectly uniform deposit; some areas will always be heavily filled while others will be lightly filled or vacant. Resolution is thereby limited. The analysis shows how a deposit becomes more uniform as the number of atoms deposited increases. It predicts optimal amounts of deposition for various shadowing angles. The analysis also provides a rationale for the way in which deposition grain coarsens and resolution worsens as the angle of shadow is made more steep. Computer-generated “ideal” depositions are compared with real shadow grains achieved under equivalent experimental conditions. The simulations are also compared with deposits achieved by novel shadowing methods. Ways to improved metal evaporation technique are suggested by the analysis and these are discussed.     

Assessment of Barley Quality by Light Transmission - the Rapid LTm meter

An estimate of the quality of barley endosperm can be obtained from the proportion of light that is transmitted through the grain. Barleys with steely endosperm structure transmit more light than those with mealy endosperm structure. The LTm meter can be used to assess these grains quickly, simply and effectively. By analysing single grains of each sample it is possible to obtain an estimate of endosperm homogeneity. LTm assessments of endosperm quality and homogeneity are related to the quality of malt made from that barley as indicated by either the Calcofluor test or by the LTm meter itself. Thus the LTm meter can be used to predict malting performance from barley quality.     

The fan effect: New results and new theories.

The fan effect (J. R. Anderson, see record 1975-06644-001) has been attributed to interference among competing associations to a concept. Recently, it has been suggested that such effects might be due to multiple mental models (G. A. Radvansky, D. H. Spieler, & R. T. Zacks, see record 1993-16287-001) or suppression of concepts (M. C. Anderson & B. A. Spellman, see record 1995-16174-001); A. R. A. Conway & R. W. Engle, see record 1994-08314-001). It was found that the Adaptive Control of Thought—Rational (ACT-R) theory, which embodies associative interference, is consistent with the results of G. A. Radvansky et-al. and that there is no evidence for concept suppression in a new fan experiment. The ACT-R model provides good quantitative fits to the results, as shown in a variety of experiments. The 3 key concepts in these fits are (a) the associative strength between 2 concepts reflects the degree to which one concept predicts the other, (b) foils are rejected by retrieving mismatching facts; and (c) participants can adjust the relative weights they give to various cues in retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A cell-based screen for function of the four-helix bundle protein Rop: a new tool for combinatorial experiments in biophysics

Combinatorial methodologies have revolutionized studies in biomolecular function, but they have so far proven less useful for understanding macromolecular structure and stability. This is largely because of the difficulty of screening libraries of molecules for biophysical properties, and the difficulty of interpreting structural effects in complicated molecules. Here, we report a novel, robust, cell-based screen for function of the four-helix bundle protein, Rop. By expression of green fluorescent protein from a ColE1 plasmid, the screen reports the copy number of the plasmid, which is modulated in Escherichia coli by Rop. We have engineered the screen so that the fluorescent phenotype can correspond to either Rop activity or lack thereof. We have used the screen to demonstrate with systematically constructed Rop core variants that not all molecules that bind small stem-loop RNAs in vitro are active in vivo. Rop is well understood from structural work and systematic mutations, which makes it possible to construct rational, targeted libraries. This screen makes it possible to rapidly interrogate such libraries effectively for proper protein folding and stability. In addition to its intended utility for combinatorial experiments in biophysics, the screen will allow further dissection of the mechanism of Rop-mediated plasmid copy number regulation in vivo.     

Uses of item response theory and the testlet concept in the measurement of psychopathology.

Through the application of the statistical tools that compose item response theory—coupled with the ideas of local independence and local dependence and the concept of the testlet—the authors illustrate item analysis, scale assembly, and scoring rules for 2 scales measuring aspects of violent circumstances and tendencies. The concepts and procedures used are general and have much broader applicability for psychological measurement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibition conflict and alcohol expectancy as moderators of alcohol's relationship to condom use.

Inhibition conflict theory predicts that alcohol will decrease condom use only among individuals who are highly conflicted about using a condom, whereas expectancy theory predicts such an effect only among individuals who hold strong beliefs about alcohol's effects on sexual risk taking. In Study 1, the first of these two theories was tested using a newly developed measure of conflict. Data from 308 college students who reported on the first time they had sexual intercourse with their most recent partner (FMRP) supported the utility of this measure and showed that quantity of alcohol consumed was negatively associated with condom use only among high-conflict individuals. In Study 2, 17–25-year-old respondents reported on their first sexual intercourse, FMRP, and last intercourse (ns = 465, 1136, and 984, respectively). In a simultaneous test of both inhibition conflict theory and expectancy theory, amount of alcohol consumed was found to be negatively associated with condom use at first intercourse among individuals high in both conflict and expectancy, at FMRP among high-expectancy individuals, and at last intercourse among high-conflict individuals. These results lend partial support to both theories of alcohol's effects and suggest that an integration of these two perspectives will ultimately be required if researchers are to model adequately alcohol's effects on human social behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Convergence and divergence of themes in successful psychotherapy: An assimilation analysis.

Theme convergence is the linking of seemingly unrelated problem domains as they advance through assimilation stages-a developmental sequence of cognitive and affective changes through which problematic content is hypothesized to pass during successful psychotherapy. Theme divergence is the contradiction or conflict of solutions to different problems, so that progress in one domain leads to stagnation or regression in another domain. An intensive qualitative method called assimilation analysis was used to examine theme convergence and divergence in a successful psychodynamic psychotherapy with a 20–yr–old female patient. Because specific problems often fail to progress monotonically, even in successful psychotherapy cases, it is suggested that clients' problems cannot be resolved in isolation; instead, they may influence each other toward resolution or stagnation in complex and unpredictable ways. (PsycINFO Database Record (c) 2010 APA, all rights reserved)