Comparison of the observed distribution of aflatoxin in shelled peanuts to the negative binomial distribution

Suitability of the negative binomial distribution for use in estimating the probabilities associated with sampling lots of shelled peanuts for aflatoxin analysis has been studied. Large samples, called “minilots,” were drawn from 29 lots of shelled peanuts contaminated with aflatoxin. These minilots were subdivided into ca. 12 lb samples which were analyzed for aflatoxin. The mean and variance of these aflatoxin determinations for each minilot were determined. The shape parameterk and the mean aflatoxin concentrationm were estimated for each minilot. A regression analysis indicated the functional relationship betweenk andm to be:k=(2.0866+2.3898m) × 10⁻⁶. The observed distribution of sample concentrations from each of the 29 minilots was compared to the negative binomial distribution by means of the Kolmogorov-Smirnov test. The null hypothesis that each of the true unknown distribution functions was negative binomial was not rejected at the 5% significance level for all 29 comparisons. Journal Series Paper of the North Carolina State University Agricultural Experiment Station, Raleigh, N.C.     

Specific limited hydrolysis and phosphorylation of food proteins for improvement of functional and nutritional properties

Limited specific hydrolysis of casein byStaphylococcus aureus V8 protease was used to produce 2% and 6.7% hydrolysates (2 and 6.7% of the peptide bonds hydrolyzed), each containing five polypeptides (by gel filtration) ranging in size from ∼ 16,000 to ∼1,000 daltons. The mixtures of polypeptides had substantially increased solubilities at pH 4.0–4.5, near the isoelectric point of casein. In general, the emulsifying activity index was less for the hydrolysates than for casein; the emulsion stability was higher for the 2% hydrolysate than was the emulsion from casein. Phosphorylation of zein markedly increased the water solubility of zein above and below pH 4. When the free amino acids tryptophan and/or lysine were added to zein in the presence of POC1₃, some amino acids were covalently bound to zein, in addition to covalent attachment of phosphate groups. Threonine did not become incorporated into zein by this method. These derivatives were much more soluble than zein above and below pH 4, the minimum solubility point. A derivative containing 0.98 mol P/mol of zein, along with 1.05% tryptophan and 0.24% lysine, had a relative growth effect onTetrahymena thermophili of 49% that of casein, in comparison to 4.5% for unmodified zein. All the modified zeins had improved emulsifying activity indices.     

Diffusion tensor analysis with invariant gradients and rotation tangents

Guided by empirically established connections between clinically important tissue properties and diffusion tensor parameters, we introduce a framework for decomposing variations in diffusion tensors into changes in shape and orientation. Tensor shape and orientation both have three degrees-of-freedom, spanned by invariant gradients and rotation tangents, respectively. As an initial demonstration of the framework, we create a tunable measure of tensor difference that can selectively respond to shape and orientation. Second, to analyze the spatial gradient in a tensor volume (a third-order tensor), our framework generates edge strength measures that can discriminate between different neuroanatomical boundaries, as well as creating a novel detector of white matter tracts that are adjacent yet distinctly oriented. Finally, we apply the framework to decompose the fourth-order diffusion covariance tensor into individual and aggregate measures of shape and orientation covariance, including a direct approximation for the variance of tensor invariants such as fractional anisotropy.     

A comparison of word recognition and reading performance in foveal and peripheral vision

Word recognition thresholds and rapid serial visual presentation (RSVP) reading rates for both unrelated words and meaningful sentences were examined across the visual field. Both word recognition thresholds and RSVP reading rates for unrelated words can be equated across the visual field by an increase in size scale. RSVP reading rates for meaningful sentences cannot be equated across the visual field, with the fovea demonstrating a qualitative superiority over the periphery, irrespective of scale. The results suggest that the early visual machinery which underlies word recognition is the same across the visual field apart from a change in scale, whilst the periphery is qualitatively inferior to the fovea at interpreting sentences with meaning.     

Cognitive accessibility and sentiment override—starting a evolution: Comment on Fincham et al. (1995).

F. D. Fincham, P. C. Garnier, S. Gano-Phillips, and L. N. Osborne (see record 1995-21088-001) present a methodology new to the marital arena (reaction time assessment) and use it to illuminate a classic issue in the marital area, sentiment override. In doing so, they highlight the potential of this new methodology for enhancing marital assessment and allowing for the rigorous test of theory. However, the promise of this specific methodology and its implications for marital assessment may be less important than the broader research agenda implied. Because Fincham et al utilized an information processing approach developed within the robust tradition of social-cognition research, they open the marital area to a broad array of potential assessment techniques and implicitly invite the field to join them in a profound reconceptualization of the role of cognition in shaping each spouse's response to the other. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Densitometric equipment for rapid quantitation of aflatoxins on thin layer chromatograms 1

A densitometric instrument (Spotmeter) has been designed for rapid measurement of aflatoxin on thin layer chromatographic plates. The Spotmeter measures the total amount of fluorescence of the aflatoxin spot and thus eliminates the need for scanning mecha-nisms, plotters and integrators incorporated into most commercially available densitometers used for aflatoxin analyses. In comparison with a Schoeffel SD 3000 Spectrodensitometer, the Spotmeter was more accurate in one test and at least equally accurate in another test. The Spotmeter made measurements in 1/4 the time required for the Spectrodensitometer and would cost about 1/6 as much as commercially available densitometers suitable for aflatoxin analyses. 1 Paper Number 6203 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC.     

Electric field mapping system using an optical-fiber-basedelectrooptic probe

A microwave electric-field mapping system based on electrooptic sampling has been developed using micromachined GaAs crystals mounted on gradient index lenses and single-mode optical fibers. The probes are able to detect three orthogonal polarizations of electric fields and, due to the flexibility and size of the optical fiber, can be positioned not only from the extreme near-field to the far-field regions of microwave and millimeter-wave structures, but also inside of enclosures such as waveguides and packages     

Local,global, and elementary stoichiometry

Stoichiometry refers to conservation of atomic species. In this article, local refers to a point at the continuum level, global refers to the macroscopic balance level, and elementary refers to conservation of atomic species associated with distinct kinetic steps. The role of stoichiometry in the determination of the pivot matrix and the mechanistic matrix is presented. The elements of both these matrices are referred to as stoichiometric coefficients; however, both sets of coefficients are different and both play different roles in the analysis of chemical reactors. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Magnetic Levitation of liquid helium

We report on the stable levitation of liquid helium drops of up to 2 cm diameter in a magnetic trap at temperatures down to 1.5 K in the earth's gravitational field. The production and properties of a magnetic trap for diamagnetic materials is discussed. The behavior of liquids in such a trap is analyzed, including the deformation of a liquid drop by the trap forces. We frequently observe two drops in the magnetic trap which are held in apparent contact for up to 3 minutes without coalescing. This non-coalescence effect was only seen above the superfluid transition temperature. We explain this effect in terms of the existence of a vapor layer between the drops caused by evaporation of the drops, much like the suspension of a liquid drop above a hot surface known as the Leidenfrost effect.     

Phase equilibria in the system CdO-ZnO-B2O3 at 850°C

Phase equilibria in the system CdO-ZnO-B₂O₃ were investigated at 850 °C using quenching and X-ray powder diffraction techniques. The binary phases reported previously were confirmed. The ternary phase diagram was solved and a new phase postulated: 3CdO · 3ZnO · 2B₂O₃. X-ray powder data are given for this. Solid solution effects were investigated for the primary and binary phases by comparison of patterns; none were detected. These results are compared with those of a previous determination and the differences discussed.