A systematic review and meta-analysis of tenderness metrics in control groups used in comparative nutrition experiments.

This review reports the pork quality attributes, Warner-Bratzler Shear Force, Slice Shear Force, Star Probe, pH, marbling, color (Minolta L*/L or Hunter L*/L), and sensory tenderness evaluation, in control groups used in comparative nutrition experiments over the past 20 yr. The original aim of this study was to evaluate if changes in pork quality based on the above metrics occurred over time. To address this question, it was anticipated that data may come from 3 sources with decreasing relevance: representative retail pork surveys, representative post-harvest carcass surveys, and control groups from comparative nutrition experiments. To identify the study population, a review of studies reported in Centre for Agricultural Biosciences International Abstracts (Web of Knowledge; 1994-2014) was conducted. Two national level surveys of retail pork and 146 relevant nutritional experiments studies, with 228 control groups, were identified by the search. It was not possible to conduct a meta-analysis of the retail pork surveys based on only 2 time points. For the comparative studies, a random effects meta-analysis was conducted with year as a covariate to assess the impact of time on the outcome. In the absence of modifiers, there was no evidence of meaningful change in the mean Warner-Bratzler Shear Force, pH, color, marbling, or sensory scores over the study period. There was evidence of substantial between-study heterogeneity in the characteristics of control pigs used over the years for Warner-Bratzler Shear Force and measures of color. The absence of publicly-available representative surveys of pork quality meant the changes in pork quality over time were not clear. If changes in pork quality have occurred, the data suggest that pigs used as controls in experiments may have become less representative of commercial pigs over time and the translatability of study findings from nutrition experiments might be reduced over time. Alternately, if commercial pigs have not changed, then control pigs reflect this. The study does not address if control groups in other experimental intervention studies had similar tenderness patterns as reported here for nutritional interventions. A large amount of potentially available data was excluded from the analysis due to incomplete reporting in the original study reports.

Survival and Injury of Listeria monocytogenes , Listeria innocua and Listeria ivanovii in Ground Pork Following Electron Beam Irradiation †.

The sensitivity of five strains of Listeria to electron beam irradiation in ground pork as well as the extent of sublethal radiation injury exhibited by each were investigated. Ground pork was inoculated with one of five strains of Listeria and irradiated with from 0 to 1.25 kGy at 0.25 kGy intervals. Listeria innocua NADC 2841 was more radiation-resistant (D10 = 0.638 kGy) than L. monocytogenes NADC 2045 Scott A (D10 = 0.447 kGy), L. monocytogenes NADC 2783 (a hamburger isolate) (D10 = 0.424 kGy), L. monocytogenes ATCC 15313 (D10 = 0.445 kGy), and L. ivanovii NADC 3518 (D10 = 0.372 kGy), when recovered on tryptic soy agar supplemented with 0.6% yeast extract. D10 values for L. innocua , L. ivanovii , and L. monocytogenes ATCC 15313 were lower when cells were recovered on modified Oxford medium. These three strains were susceptible to radiation-induced sublethal injury, with the numbers of injured organisms increasing with irradiation dose. The two pathogenic strains of L. monocytogenes were not injured significantly at the dose levels used. The results show that the dose range currently being considered by the Food and Drug Administration for the irradiation of beef and pork (1.5 to 4.5 kGy) is adequate for the elimination of L. monocytogenes from pork.

Semantic judgments of compressed monosyllables: evidence for phonetic symbolism.

Both frequency and speed of utterance have been implicated in studies of phonetic symbolism. Therefore, these two variables were manipulated independently. Three monosyllables were recorded and distorted by either increasing or decreasing frequency, holding speed constant, and by increasing or decreasing speed, holding frequency constant. The subjects were 15 college students who rated the resulting 15 stimuli (3 monosyllables X fast speed-normal frequency, slow speed-normal frequency, normal speed-high frequency, normal speed-low frequency, and normal speed-normal frequency) using 15 bipolar adjective scales, chosen on the basis of previous semantic differential and phonetic symbolism research. Five separate factor analyses were applied to the data. It was found that the normal speed-low frequency, slow speed-normal frequency, and normal speed-normal frequency stimuli generated approximately the same factors, while the fast speed-normal frequency and normal speed-high frequency stimuli generated factors similar to each other but with some notable differences. Separate analyses of variance were applied to the bipolar adjectives using speed, frequency, and vowels as main effects. The 15 analyses showed that subjects did judge the monosyllables as different on the basis of both speed and frequency. The implications of this study for phonetic symbolism research are discussed.

Implications for phonetic symbolism: the relationship between pure tones and geometric figures.

In studies of phonetic symbolism, the most commonly cited attribute of speech relevant to the phenomenon has been frequency. The present study was conducted in order to examine the relationship between pure tone frequencies and geometric figures. A pure tone oscillator was constructed which produced tones in a continuous sweep from 4-12,250 Hz. Six geometric shapes were employed and varied along three binary dimensions (size, complexity, and density) producing a total of 48 stimulus figures. Twelve male and twelve female subjects adjusted pure tone frequencies until they "best fit" the visually presented geometric figure in a complete within-subject, block-randomization design of 48 trials. There was consistency in the assignment of pure tone frequencies to the dimensions of the geometric figures. Round figures (circles and ellipses) generally received lower frequency assignments than other figures, and the shape by size interaction was also found to be statistically significant. The results are interpreted in light of recent research in psycholinguistics and in particular to the hypothesis of a "universal phonetic symbolism".

Growth response of three vegetables to smooth- and crenate-tailed females of three species of pratylenchus.

The effect of morphological variants of females of Pratylenchus penetrans, P. neglectus, and P. crenatus on the growth of three vegetables was studied. Variants were characterized by having either a smooth or crenate tail terminus. Pea was inoculated with variants of P. penetrans, one female per seedling, and grown at light intensities ranging from 1,350 to 21,600 lux in a series of five experiments. Only crenate-tailed females of P. penetrans suppressed the growth of pea and only when pea was grown at 3,900 lux. Radish was inoculated with morphological variants of P. penetrans, P. neglectus, and P. crenatus, four females per seedling, and grown at 3,900 lux in two experiments. Again, truly creuate-tailed females of P. penetrans inhibited growth. The two variants of P. penetrans had a similar infectivity, greater than that of the other two species of Pratylenchus. Only crenate-tailed P. penetrans reproduced on radish. Onion was inoculated with variants of P. penetrans and P. crenatus, four females per seedling, and grown at 14 C at 12,900 lux. Again, only crenate-tailed P. penetrans inhibited growth. The variants of P. penetrans had a similar infectivity, greater than that of P. crenatus. Neither species reproduced on onion at low temperatures.

The effect of rearing environments on the contrafreeloading phenomenon in rats.

Eight naive rats were reared in enriched or impoverished environments for 39 days after weaning and then lived in operant chambers, in which they could obtain food pellets freely or by lever pressing, for 25 or 30 days. The animals raised in an impoverished environment acquired the bar-press response quickly when placed in the operant chambers and maintained a preference for obtaining food via bar pressing. Animals raised in an enriched environment did not learn to lever press, as demonstrated by low levels of responding and the lack of bar pressing when free food was subsequently removed. It was concluded that restricting animals' postweaning environments facilitated learning in a choice situation, probably because of increased activity levels. The results are interpreted in relation to previous studies on rearing environments and on contrafreeloading.

Morphological variation in Pratylenchus penetrans.

Variability of morphological characters used to separate Pratylenchus penetrans from other species of the genus was studied in a population originating from a single gravid female. Pronounced heteromorphism was observed and characterized. About 30% of females had a crenate-tail terminus. Several shapes of stylet knobs were characterized; 50% of them were anteriorly flattened to indented. The outer margin of the cephalic framework extended into the body from one-half to two annules. The shape of the spermatheca varied from round to oval. A fifth lateral line was observed in many specimens. Environmental factors, and particularly the host plant, influenced such morphometric characters as body length, width, esophagus length, stylet length, V value, a and b' ratios, as well as qualitative characters such as tail terminus, growth of ovary, and shape of median bulb. Nematodes reared on pea and cabbage had a higher percentage of females with a crenate-tail terminus than those from tomato, rye, beet, and alfalfa callus culture. Nematodes from peas were longer and wider; they often had gonads that extended to esophagi, but they had shorter esophagi amt stylets than those from callus culture. Populations from different geographical locations also exhibited variahility in morphological characters, as did the Cornell population. The validity of many characters used in species identification is discussed, and the possibility that other related Pratylenchus species are conspecific with P. penetrans is suggested.

Sex expression and tail morphology of female progenies of smooth-tail and crenate-tail females of Pratylenchus penetrans.

An analysis of the offspring of single smooth- and crenate-tail females of Pratylenchus penetrans indicated the existence of progenies containing only males or females. Of the 80 progenies analyzed, 46 contained females with smooth and crenate tails. In general, regardless of the mother's tail type, most females possessed crenate tails, although more crenate-tail females originated from a crenate-tail female than from a smooth-tail female. Twenty-three progenies contained only females with crenate tails, most of them originating from crenate-tail females. One progeny originating from a smooth-tail female contained only females with smooth tails. No simple interpretation of the inheritance of tail type could be attempted because selection pressure favored females with crenate tails when P. penetrans was reared on Wando pea plants.