The effects of postnatal litter size on preand postweaning growth, daughter 's litter size and rebreeding performance of the dam were examined in rats that had undergone 14 generations of selection for rate (LG) or efficiency (LE) of postweaning protein gain followed by relaxed selection, and in a randomly selected control line (C). Data came from generations 23 to 24 (standardized litters) and...

Although dual-task interference is ubiquitous in a variety of task domains, stop-signal studies suggest that response inhibition is not subject to such interference. Nevertheless, no study has directly examined stop-signal performance in a dual-task setting. In two experiments, stop-signal performance was examined in a psychological refractory period task, in which subjects inhibited one respon...

The standard bottleneck model of the psychological refractory period (PRP) assumes that the selection of the second response is postponed until the first response has been selected. Accordingly, dual-task interference is attributed to a single central-processing bottleneck involving decision and response selection, but not the execution of the response itself. In order to critically examine the...

We generalize the classical Cayley-Dickson doubling process starting with a quaternion algebra over a field F by allowing the scalar in the doubling to be an invertible element in the algebra. We investigate the resulting eight-dimensional algebras over F and show that they are division algebras for all scalars chosen in D outside of the base field F , if D is a division algebra.

The hypothesis that episodic memory retrieval can occur in parallel with other cognitive processes was tested in 2 experiments. Participants memorized words and then performed speeded cued recall (Experiment 1) or speeded yes-no recognition (Experiment 2) in a dual-task situation. The psychological refractory period design was used: The participant was presented with a single test item at vario...

A divergent selection experiment for serum IGF-I concentration was established in 1989 at the Eastern Agricultural Research Station located in Belle Valley, Ohio. One hundred spring-calving (50 high line and 50 low line) and 100 fall-calving (50 high line and 50 low line) cows with unknown IGF-I concentrations were randomly assigned to the 2 divergent selection lines. Results of this study incl...

The objective of this study was to determine the effects of addition of spray-dried plasma protein (SDPP) and Cu to nonmedicated diets on growth performance and intestinal morphology in weaned pigs reared in sanitary or nonsanitary environments. Weanling pigs (n = 192, 18 +/- 2 d of age, 6.0 +/- 0.2 kg of BW) were assigned to 8 treatments arranged factorially, including 2 dietary levels of SDPP...

Net feed conversion efficiency (NFCE) describes whether an animal eats more or less feed than expected for its size and growth rate. Early results from the Trangie NFCE Project, and from the Beef CRC, show that considerable variation in NFCE exists within each of the British breeds tested and is moderately heritable. Estimates of heritability for average daily gain, 365-day weight, feed intake,...

The Dimension Action (DA) model asserts that the visual system is modular, and that each task involves multiple-response mechanisms rather than a unitary-response selection mechanism. The model has been supported by evidence from single-task interference paradigms. We use the psychological refractory period paradigm and show that dual-task performance can also be explained by the DA model. In 6...