Comparison of Antifungal and Antioxidant Activities of <Emphasis Type="Italic">Acacia mangium</Emphasis> and <Emphasis Type="Italic">A. auriculiformis</Emphasis> Heartwood Extracts

The effect of heartwood extracts from Acacia mangium (heartrot-susceptible) and A. auriculiformis (heartrot-resistant) was examined on the growth of wood rotting fungi with in vitro assays. A. auriculiformis heartwood extracts had higher antifungal activity than A. mangium. The compounds 3,4,7,8-tetrahydroxyflavanone and teracacidin (the most abundant flavonoids in both species) showed antifungal activity. A. auriculiformis contained higher levels of these flavonoids (3.5- and 43-fold higher, respectively) than A. mangium. This suggests that higher levels of these compounds may contribute to heartrot resistance. Furthermore, both flavonoids had strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and laccase inhibition. This suggests that the antifungal mechanism of these compounds may involve inhibition of fungal growth by quenching of free radicals produced by the extracellular fungal enzyme laccase.     

Growth inhibition of Escherichia coli O157:H7 and Listeria monocytogenes by carvacrol and eugenol encapsulated in surfactant micelles

Growth inhibition of four strains of Escherichia coli O157:H7 (H1730, F4546, 932, and E0019) and Listeria monocytogenes (Scott A, 101, 108, and 310) by essential oil components (carvacrol and eugenol) solubilized in nonionic surfactant micelles (Surfynol 465 and 485W) was investigated. Concentrations of encapsulated essential oil components ranged from 0.02 to 1.25% depending on compound, surfactant type, and surfactant concentration (0.5 to 5%). Eugenol encapsulated in Surfynol 485W micelles was most efficient in inhibiting growth of the pathogens; 1% Surfynol 485W and 0.15% eugenol was sufficient to inhibit growth of all strains of E. coli O157:H7 and three of four strains of L. monocytogenes (Scott A, 310, and 108). The fourth strain, L. monocytogenes 101, was inhibited by 2.5% Surfynol and 0.225% eugenol. One percent Surfynol 485W in combination with 0.025% carvacrol was effective in inhibiting three of four strains of E. coli O157:H7. Strain H1730 was the most resistant strain, requiring 0.3% carvacrol and 5% surfactant for complete inhibition. Growth inhibition of L. monocytogenes by combinations of carvacrol and Surfynol 465 ranged between 0.15 and 0.35% and 1 and 3.75%, respectively. Generally, the antimicrobial activity of Surfynol 465 in combination with eugenol was higher than that for the combination with carvacrol. The potent activity was attributed to increased solubility of essential oil components in the aqueous phase due to the presence of surfactants and improved interactions of antimicrobials with microorganisms.     

Soybean unsaponifiables: Chromatographic separations and characterization

Unsaponifiables extracted from 10 different lots of refined soybean oil were subjected to liquidliquid chromatographic separations. Three major fractions were obtained. The least polar hydrocarbon fraction constituted 15 to 30% of the unsaponifiables; the most highly polar fraction contained the steroids constituting 35 to 45% of the unsaponifiables. The fraction of intermediate polarity varied in composition from lot to lot, but usually it contained more than 50% of the unsaponifiables. These basic fractions were analyzed by thin layer, gas-liquid chromatography, and by chemical tests for functional groups. To determine the effects of soybean unsaponifiables on the oxidative and organoleptic stability of edible fats, various concentrations of the extracted and fractionated materials were examined in cottonseed oil. Effects of extraction methods on yields, fractionation characteristics, and composition of the different lots of soybean unsaponifiables are discussed. Presented at the AOCS meeting in Chicago, 1961. Division, Agricultural Research Service, USDA.     

Automated analysis of total nitrogen in solid biological material

An automated method for determination of total nitrogen in solid biological material is described. The use of homogenised suspensions of material to be analysed is recommended in estimations of organic nitrogen. Dried ground material was found to be unsuitable because of losses of nitrogen during drying of sample material. The results obtained with this method were both accurate and highly reproducible.     

Early stages of reduction of nickel oxide single crystals: An investigation by transmission electron microscope

Because of the practical importance of the reaction, a great deal of work has been done on the reduction of metallic oxides to metals. In this laboratory all stages of the reduction of nickel oxide to nickel are being studied using a transmission electron microscope. Small, pre-thinned single crystals of nickel oxide have been reduced outside the microscope in a hydrogen atmosphere and the reduction temperatures and times were varied. The resulting foils were then examined in a Phillips 301 100 kV electron microscope and the relationships between the nickel metal particles and the nickel oxide single crystal matrix were established. During the early stages of the reduction both epitaxial and non-epitaxial nuclei were observed, the latter becoming predominant as reduction time progressed. The nuclei were frequently separated from the nickel oxide matrix by a fissure and as they impinged and coalesced, a large scale structure resulted with internal porosity as often seen by optical microscopy.     

A further study of the McKinney Reporting Test scores.

The McKinney Test was given to 371 first pilots and 428 copilots prior to beginning B-29 Combat Crew Training. Various criteria were used by psychologists to make over-all ratings of adjustment. 2 extreme criterion groups of 200 Ss each were then selected to define the maximum adjustment differences in the population. It was predicted that the upper criterion group members could perform on the McKinney Test at a more consistent rate and would be less susceptible to the frustrating conditions. The differences between the criterion groups were in the predicted direction and statistically significant for only 5 of the 18 possible comparisons. Lack of agreement with the Douglass-Brown study suggests that the measures of frustration reaction reflected by both sets of data are unstable. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Programmed polymer light-scattering data

An ALGOL computer program has been devised to manipulate light-scattering data from the Brice-Phoenix photometer. The input consist of experimental values of the galvanometer deflections and filter factors used for each concentration c and angle of measurement θ. These are transformed to the appropriate variables in the fundamental equation including the particle scattering factor, viz: c/Qθ = (W/K^*)M?_w^?1[1 + (16/3) × π²n₁²λ〈S²〉 sin² (θ/2)] + (W/K^*)2A₂c + (W/K^*)3A₃c² in which Qθ is a corrected from of the Rayleigh ratio and (W/K^*) is a composite constant term for the instrument and polymer–solvent system. By writing X?_ij for the variable c/Q_θ at θ_i and c_j, a function X is found by least squares to fit X?_ij, thus X = l + m sin (θ/2) + nc_j + bc_j². The equations arising from minimizing Σ_i^K=1 Σ_j^L=1 (X_ij ? X?_ij)² are solved by the computer to yield the best-fitting coefficients l, m, n, and b. These can then be related simply to the molecular weight, root-mean-square radius of gyration, second and third virial coefficients, respectively. The final portion of the program is designed to check the fit of these coefficients. It yields a table of the differences between all experimental c/Qθ values and the coressponding ones obtained by inserting the derived l, m, n, and b into the fundamental equation. The procedure has been tested satisfactorily by using a well-standardized sample of polystyrene in toluene at 30°C. and a wavelength of 436 mμ.     

An examination of students' attitudes toward television as a medium of instruction in a psychology course.

74 students enrolled in an elementary psychology course taught through 2 weekly television sessions and 2 weekly discussion-group sessions were asked (1) whether they would take another course using television and (2) whether the on-campus discussion added anything. 70% of the Ss answered YES to the first question, and 42% answered YES to the second. Open-ended responses revealed reasons for the answers given. (PsycINFO Database Record (c) 2010 APA, all rights reserved)