The dorsal tegmental noradrenergic projection: An analysis of its role in maze learning.

Evaluated the hypothesis that the noradrenergic projection from the locus coeruleus (LC) to the cerebral cortex and hippocampus is an important neural substrate for learning. Four experiments were conducted with 61 male Wistar rats. Maze performance was studied in Ss receiving either electrolytic lesions of LC or 6-hydroxydopamine (6-OHDA) lesions of the dorsal tegmental noradrenergic projection. The LC lesions did not disrupt the acquisition of a running response for food reinforcement in an L-shaped runway, even though hippocampal-cortical norepinephrine (NE) was reduced to 29%. Greater telencephalic NE depletions (to 6% of control levels) produced by 6-OHDA also failed to disrupt the acquisition of this behavior or to impair the acquisition of a food-reinforced position habit in a 'T'-maze. Neither locomotor activity nor habituation to a novel environment was affected by the 6-OHDA lesions. Ss with such lesions were, however, found to be significantly more distractible than were controls during the performance of a previously trained response. The hypothesis that telencephalic NE is of fundamental importance in learning was not supported. The data suggest that this system may participate in attentional mechanisms. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotions and the microcomputer: An exploratory study of young children's responses

The emotional effects of early microcomputer use are of interest to educators and child development researchers. This study took a microanalytic emotion coding system which has been used in basic child development research, and applied it to exploring the effects of computer use on children's emotional responses. Sixteen 5-year-old children were videotaped while using three pieces of software (a drawing program, a face construction program, and a counting program). All three pieces elicited more active, positive, and complex facial expressions than did a comparison segment of television watching. Greater levels of concentration and more socially responsive behavior were also seen in the computer conditions. The drawing program tended to elicit more indicators of concentration and social engagement than the other two, although individual preferences and sample size made conclusions tentative. Results appear to reflect the motivational value of emotions and children's interest in experiences which offer autonomy and control. On the basis of this exploratory study, the methodology seems to have potential for investigating other aspects of children's emotional responses to computers.     

Solution structure, rotational diffusion anisotropy and local backbone dynamics of Rhodobacter capsulatus cytochrome c2

The solution structure, backbone dynamics and rotational diffusion of the Rhodobacter capsulatus cytochrome c2 have been determined using heteronuclear NMR spectroscopy. In all, 1204 NOE-derived distances were used in the structure calculation to give a final ensemble with 0.59(+/-0.08) A rms deviation for the backbone atoms (C, Calpha and N) with respect to the mean coordinates. There is no major difference between the solution structure and the previously solved X-ray crystal structure (1.07(+/-0.07) A rms difference for the backbone atoms), although certain significant local structural differences have been identified. This protein contains five helical regions and a histidine-heme binding domain, connected by a series of structured loops. The orientation of the helices provides an excellent sampling of angular space and thus allows a precise characterization of the anisotropic diffusion tensor. Analysis of the hydrodynamics of the protein has been performed by interpretation of the 15N relaxation data using isotropic, axially asymmetric and fully anisotropic diffusion tensors. The protein can be shown to exhibit significant anisotropic reorientation with a diffusion tensor with principal axes values of 1.405(+/-0.031)x10(7) s-1, 1.566(+/-0.051)x10(7) s-1 and 1.829(+/-0.054)x10(7) s-1. Hydrodynamic calculations performed on the solution structure predict values of 1.399x10(7) s-1, 1.500x10(7) s-1 and 1.863x10(7) s-1 when a solvent shell of 3.5 A is included in the calculation. The optimal orientation of the diffusion tensor has been incorporated into a hybrid Lipari-Szabo type local motion-anisotropic rotational diffusion model to characterize the local mobility in the molecule. The mobility parameters thus extracted show a quantitative improvement with respect to the model-free analysis assuming isotropic reorientation; helical regions exhibit similar dynamic properties and fewer residues require more complex models of internal motion. While the molecule is essentially rigid, a tripeptide loop region (residues 101 to 103) exhibits flexibility in the range of 20 to 30 ps, which appears to be correlated with the order in the NMR solution structure.     

Prolegomenon to the study of apparatus in early psychological laboratories circa 1875-1915.

Although the initial phase of experimental psychology is often referred to as the era of "brass instrument psychology," historians have generally ignored the equipment that was used in favor of the contributions of individuals and "schools." the present paper urges historians to explore the ways in which the linkage between mechanical facilities and concepts interacted and to trace the effects of technological as well as theoretical difficulties. Although attrition of relevant data has occurred, some existent sources are identified including stock lists of manufacturers, laboratory manuals and university inventories, photographs, journal articles, and reminiscences of psychologists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fatty acids of pimiento pepper seed oil

Pimiento pepper (Capsicum annum L.) seed oil was shown to contain 66–71% linoleic acid with smaller quantities of 16 and 18 carbon saturated and monounsaturated fatty acids. Neither geographical location nor location within pimiento processing plants influenced the level or composition of the seed oil. Two varieties of bell-type peppers were shown to have essentially the same seed oil composition as that of pimientos. Oil extracted from the fruit wall and placenta of pimientos was red and contained high levels of linolenic and small quantities of very long chain polyunsaturated fatty acids. Journal Series Paper No. 462, Georgia Experiment Station, Experiment, Ga.     

Frontiers of current research: Section introduction.

This article introduces the special section in the current issue of the American Psychologist. The articles in this section appear in two groups. The first is titled "Developmental Perspectives"; the second is titled "Learning and Teaching." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Compressed Data Structure for Surface Representation

One of the standard methods of simplifying the task of obtaining a shaded image of a solid object is to represent it by a polyhedron. Another method is to use sculptured surface modelling which represents surfaces by collections of surface patches. Using either method the surfaces can be approximated by facets, which are simple to shade according to photometry information.
To obtain a smooth image in regions of high curvature, the surface would typically be required to have hundreds or thousands of facets. Because of the large number of facets involved, it is extremely important that geometrical and topological information is stored in an efficient manner. This information must include all that is required for an unambiguous representation of the solid(s) in question.
The compressed data structure (CDS) is suitable for this purpose, and is capable of defining the majority of surfaces. The structure is intended to minimise the amount of data stored, with as much information as possible being implied. The CDS can be easily generated knowing the order of the vertices defining the surface.     

Flexible monitoring. Bringing technology to the patient

Flexible monitoring helped to establish an intermediate care unit, close an intensive care unit (ICU) and reduce cost by decreasing length of stay (LOS) and matching patients to appropriate care. These efforts saved the hospital $3,260,215 over the first year while maintaining positive patient outcomes.     

Recognition memory in preschool children.

Tested 18 males and 18 females from each of 2 age groups (mean ages, 37 and 53 mo) on a recognition test under each of 3 conditions: (a) verbal only, (b) visual only, and (c) verbal-visual. Correct recognition was obtained for all Ss. Older Ss, however, performed significantly better than younger. Neither age group benefited from E-provided labels; performance in the visual-only and visual-verbal conditions was comparable. It is concluded that the development of mechanisms other than verbal mediator production must account for any age-related improvement in recognition performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the reproducibility of Tg measurements on polystyrene using d.s.c.

In determining the reproducibility of T_g data of a standard polystyrene measured by differential scanning calorimetry (d.s.c.), the effects of d.s.c. trace interpretation method, extrapolation to zero scan rate, polymer sample form, a thermal treatment and a thermal cycling procedure on the results were examined. The results showed that data from scanning at 8°C/min are preferred to those from extrapolation to zero scan rate while the overall reproducibility was unaffected by the d.s.c. trace interpretation method used. However, the onset of the transition step was selected to define T_g in this work. Similarly, no differences in the reproducibility of data were noted between the overall results for granular or sheet samples, although certain treatments of specific samples did produce changes in some instances. The mean value for T_g at 8°C/min was found to be 102.3°C. Imposing the thermal treatment on the samples did not significantly alter the reproducibility of the results whereas in contrast, cycling markedly improved the reproducibility of sheet sample data but left that of granules unaffected.