Dissecting Driver Behaviors Under Cognitive, Emotional, Sensorimotor, and Mixed Stressors

In a simulation experiment we studied the effects of cognitive, emotional, sensorimotor, and mixed stressors on driver arousal and performance with respect to (wrt) baseline. In a sample of n = 59 drivers, balanced in terms of age and gender, we found that all stressors incurred significant increases in mean sympathetic arousal accompanied by significant increases in mean absolute steering. The latter, translated to significantly larger range of lane departures only in the case of sensorimotor and mixed stressors, indicating more dangerous driving wrt baseline. In the case of cognitive or emotional stressors, often a smaller range of lane departures was observed, indicating safer driving wrt baseline. This paradox suggests an effective coping mechanism at work, which compensates erroneous reactions precipitated by cognitive or emotional conflict. This mechanisms’ grip slips, however, when the feedback loop is intermittently severed by sensorimotor distractions. Interestingly, mixed stressors did not affect crash rates in startling events, suggesting that the coping mechanism’s compensation time scale is above the range of neurophysiological latency.

Low and moderate doses of ionizing radiation up to 2 Gy modulate transmigration and chemotaxis of activated macrophages, provoke an anti-inflammatory cytokine milieu, but do not impact upon viability and phagocytic function

Benign painful and inflammatory diseases have been treated for decades with low/moderate doses of ionizing radiation (LD-X-irradiation). Tissue macrophages regulate initiation and resolution of inflammation by the secretion of cytokines and by acting as professional phagocytes. Having these pivotal functions, we were interested in how activated macrophages are modulated by LD-X-irradiation, also with regard to radiation protection issues and carcinogenesis. We set up an ex-vivo model in which lipopolysaccharide pre-activated peritoneal macrophages (pMΦ) of radiosensitive BALB/c mice, mimicking activated macrophages under inflammatory conditions, were exposed to X-irradiation from 0·01 Gy up to 2 Gy. Afterwards, the viability of the pMΦ, their transmigration and chemotaxis, the phagocytic behaviour, the secretion of inflammatory cytokines and underlying signalling pathways were determined. Exposure of pMΦ up to a single dose of 2 Gy did not influence their viability and phagocytic function, an important fact regarding radiation protection. However, significantly reduced migration, but increased chemotaxis of pMΦ after exposure to 0·1 or 0·5 Gy, was detected. Both might relate to the resolution of inflammation. Cytokine analyses revealed that, in particular, the moderate dose of 0·5 Gy applied in low-dose radiotherapy for inflammatory diseases results in an anti-inflammatory cytokine microenvironment of pMΦ, as the secretion of the proinflammatory cytokine interleukin (IL)-1β was reduced and that of the anti-inflammatory cytokine transforming growth factor (TGF)-β increased. Further, the reduced secretion of IL-1β correlated with reduced nuclear translocation of nuclear factor (NF)-κB p65, starting at exposure of pMΦ to 0·5 Gy of X-irradiation. We conclude that inflammation is modulated by LD-X-irradiation via changing the inflammatory phenotype of macrophages.

A learning-enabled neuron array IC based upon transistor channel models of biological phenomena

We present a single-chip array of 100 biologically-based electronic neuron models interconnected to each other and the outside environment through 30,000 synapses. The chip was fabricated in a standard 350 nm CMOS IC process. Our approach used dense circuit models of synaptic behavior, including biological computation and learning, as well as transistor channel models. We use Address-Event Representation (AER) spike communication for inputs and outputs to this IC. We present the IC architecture and infrastructure, including IC chip, configuration tools, and testing platform. We present measurement of small network of neurons, measurement of STDP neuron dynamics, and measurement from a compiled spiking neuron WTA topology, all compiled into this IC.

Self-esteem and negative affect

It was hypothesized that the Profile of Mood States (bipolar form) measures two higher-order dimensions: Positive and Negative Affect. It also was conjectured that subjects low in self-esteem report more Negative Affect than those high in self-esteem. POMS and the Self-Attitude Inventory were administered to 102 high school students. A principal component analysis of the 12 half-scale scores of POMS isolated the two affect dimensions postulated. Tests also showed that subjects low in Confidence report significantly greater Negative Affect than subjects high in Confidence. Thus, the Watson-Tellegen theory of affect is supported, and Negative Affect is linked to self-esteem.

Major changes in gene expression occur during at least four stages of development of Dictyostelium discoideum

The spectrum of proteins synthesized at different stages of development of the cellular slime mold Dictyostelium discoideum was analyzed by two-dimensional (2D) gel electrophoresis. Of the approximately 400 proteins detected by this method 189 show changes in their relative rate of synthesis. Most of these changes occur during four distinct stages of development: commencement of development immediately following removal of nutrients (early interphase), early aggregation, late aggregation, and culmination. During commencement the synthesis of 19 proteins begins, the relative rate of synthesis of 21 other proteins increases, and 16 proteins show a rapid decrease in their synthetic rate. During early aggregation the largest change occurs in the spectrum of proteins being synthesized. Specifically, the synthesis of 29 new proteins begins and an increase occurs in the relative synthetic rate of 43 others. During late aggregation, when tight cell-cell contacts form, a reduction takes place in the synthetic rate of most of these induced proteins in addition to the synthesis of 12 new proteins. At least two of these induced proteins are synthesized exclusively in prespore and eventually spore cells. Finally, during culmination, 23 new proteins begin to be synthesized and the synthetic rate of 12 other proteins increases. Five of the 23 newly synthesized proteins appear to be stalk-cell specific. In general, synthesis of spore-cell specific proteins begins just following the formation of tight aggregates while stalk-cell specific proteins are induced during culmination. The relative amounts of mRNAs coding for most of the early developmentally regulated proteins have been estimated by their translation in rabbit reticulocyte lysates and subsequent analysis of protein products by 2D gel electrophoresis. For most of those proteins whose rate of synthesis increases in vivo following starvation there is a parallel increase in the cellular level of the functional mRNAs encoding them. This suggests that the genes coding for these mRNAs may be under transcriptional control. In contrast, the mRNAs coding for most of the proteins whose synthetic rate decreases early in development are under translational control and persist in the cell in an inactive state.

Sulfated oligosaccharides block antibodies to many Dictyostelium discoideum acid hydrolases

The lysosomal hydrolases of the cellular slime mold, Dictyostelium discoideum, possess a common posttranslational modification which is extremely antigenic in rabbits and mice. Rabbit antisera and mouse monoclonal antibodies that recognize this determinant cross-react with a group of at least 40-50 highly negatively charged proteins which include most or all of the lysosomal enzymes. (Knecht, D. A., Dimond, R. L., Wheeler, S., and Loomis, W. F. (1984) J. Biol. Chem. 259, 10633-10640). The present study demonstrates that the determinant is found on certain N-linked oligosaccharides derived from one of these proteins. An esterified sulfate is absolutely required for antigenicity.