A note on Corballis (1997) and the genetics and evolution of handedness: Developing a unified distributional model from the sex-chromosomes gene hypothesis.

A unified, quantitative model for sex, twin, parent, and grandparent influences on handedness is presented. Recent research modeling the evolutionary development of genetic mechanisms for the transmission of handedness on the basis of genotype fitness has appeared to lead to the conclusion that a handedness gene cannot be located on the sex chromosomes. It is shown in this article, however, that this conclusion is not of general validity. The sex-chromosomes hypothesis is developed further, and it is demonstrated that a wide-ranging, detailed, and parsimonious account of the distribution of handedness is obtained when left-handedness is assumed to be associated recessively, and with low penetrance, with genetic variation located on the X chromosome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensory irritation evoked by the thermal decomposition products of plasticized poly(vinyl chloride)

A decrease in respiratory rate in mice during exposure to irritating airborne chemicals has been utilized as a response parameter to characterize the degree of upper respiratory tract irritation (sensory irritation) to the thermal decomposition products of plasticized poly(vinyl chloride). The plasticized poly(vinyl chloride) was placed in a low mass vertical furnace and thermally decomposed in an air atmosphere at a programmed heating rate of 20°C min^?1. The thermogravimetric study of the plasticized poly(vinyl chloride) demonstrated that two distinct weight loss fractions occurred during the decomposition process. Groups of four male swiss-webster mice were exposed to the thermal decomposition products of the first weight loss fraction in the range 0.03–0.77 mg l^?1 and to the second weight loss fraction in the range 0.03–0.38 mg l^?1. Dose-response curves were plotted by utilizing the maximum percent decrease in respiratory rate during each exposure as the response parameter. Comparison of these curves to a dose-response curve for hydrogen chloride showed that both the first and second weight loss fraction of plasticized poly(vinyl chloride) were more potent than hydrogen chloride in terms of sensory irritation. From these dose-response relationships qualitative and quantitative predictions of human responses to the thermal decomposition products of plasticized.     

Test road experiment on imminent warning rear lighting and signaling

OBJECTIVE: This paper describes an experiment directed toward refinement and initial field testing of two potential countermeasures for the problem of rear-end (RE) crashes. The countermeasures consist of "imminent warning" signals intended to direct the following driver's visual glance to the lead vehicle as it brakes rapidly to a stop and for a short time thereafter. BACKGROUND: RE crashes are the most frequently occurring type of light vehicle crash, making up at least 25% of all crashes. METHOD: A preliminary experiment was conducted to facilitate improvement of the attention-getting capability of an alternating pair of lamps. In the main experiment, an oscillating narrow beam lamp (a promising candidate from a previous experiment) and an improved alternating pair (improved as compared with that in a previous experiment) were compared with ordinary rear lighting. Seventy-two drivers were purposely distracted by in-vehicle tasks as the lead (surrogate) vehicle braked hard. RESULTS: Results showed improvements of 0.25 to 0.35 s in brake activation times for the two enhanced configurations as compared with ordinary rear lighting. CONCLUSION: The two enhanced lighting configurations show promise in reducing the number and severity of RE crashes. APPLICATION: The methods and results of this study can be applied to the future design and evaluation of automotive rear-end lighting designed to reduce RE crashes.     

Fabrication of microstructured polymer optical fibres

A methodology is presented suitable for the fabrication of a wide range of microstructured polymer optical fibres (mPOFs), a recent development where light guidance is achieved through the incorporation of a pattern of air channels that run the entire length of the fibre. We show that the key to good mPOF fabrication is a secondary draw oven that has tight control over the length (15–20 mm) and temperature (C) of the hot-zone while maintaining fibre draw tension high enough (50–150 g) to ensure an acceptable level of partial hole collapse (30–40%) due to surface tension effects. Diverse mPOFs with diameters in the range 200–1200 μm have been fabricated with typical standard deviations of 2–3 μm.     

Motor imagery theory of a contralateral handedness effect in recognition memory: Toward a chiral psychology of cognition.

The assumption that cognitive processes are independent of handedness was questioned. Five experiments with left-handed and right-handed participants centered on investigating recognition memory for the orientation of heads. Their results provided consistent evidence of a general contralateral handedness effect: Left-facing heads are more likely to be remembered correctly by right-handed participants, whereas right-facing heads are more likely to be remembered correctly by left-handed participants. Motor imagery and hemispheric differences explanations were compared. The results supported the hypothesis that the effect is a consequence of differences between handedness groups in terms of specific patterns of underlying motor activation rather than in terms of more general differences in function between cerebral hemispheres. The possibility of a chiral psychology of cognition that takes note of a person's handedness is considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exaggeration and suppression of iridescence: the evolution of two-dimensional butterfly structural colours.

Many butterfly species possess 'structural' colour, where colour is due to optical microstructures found in the wing scales. A number of such structures have been identified in butterfly scales, including three variations on a simple multi-layer structure. In this study, we optically characterize examples of all three types of multi-layer structure, as found in 10 species. The optical mechanism of the suppression and exaggeration of the angle-dependent optical properties (iridescence) of these structures is described. In addition, we consider the phylogeny of the butterflies, and are thus able to relate the optical properties of the structures to their evolutionary development. By applying two different types of analysis, the mechanism of adaptation is addressed. A simple parsimony analysis, in which all evolutionary changes are given an equal weighting, suggests convergent evolution of one structure. A Dollo parsimony analysis, in which the evolutionary 'cost' of losing a structure is less than that of gaining it, implies that 'latent' structures can be reused.     

A simple method for the direct detection of Salmonella and Escherichia coli O157:H7 from raw alfalfa sprouts and spent irrigation water using PCR

The U.S. Food and Drug Administration recognizes that raw seed sprouts are an important cause of foodborne disease and is now recommending that either spent irrigation water or final product be screened for Salmonella and Escherichia coli O157:H7 as a means of assuring the safety of product intended for consumption. In an effort to streamline such testing efforts, a simple method to preconcentrate pathogens from sprouts and spent irrigation water was investigated to facilitate the direct (without prior cultural enrichment) detection of pathogens using the PCR technique. Alfalfa sprouts and spent irrigation water were seeded with Salmonella enterica serovar Typhimurium and E. coli O157:H7 at 10(-1) to 106 CFU/g or CFU/ml, respectively. Samples were blended (sprouts only) and then centrifuged at high speed to sediment the total bacterial population. The precipitate was processed for DNA isolation, PCR amplification, and amplicon confirmation by Southern hybridization. Mean pathogen recoveries after centrifugation ranged from 96 to 99% for both pathogens in both matrices. Using primers targeting the invA gene for Salmonella Typhimurium and the stx genes of E. coli O157:H7, it was possible to detect both pathogens in alfalfa sprouts at seeding concentrations as low as 10 CFU/g. PCR detection limits for both pathogens from spent irrigation water were 10(-1) CFU/ml, the equivalent of 100 CFU/liter of water. Because spent irrigation water is constitutionally simple, it is particularly well suited for bacterial concentration by simple centrifugation steps. In this study, progress was made toward development of a rapid, inexpensive, and sensitive method for the detection of sprout-associated pathogens that is relevant to current industrial practices and needs.     

Assessment of dependency, agreeableness, and their relationship.

Agreeableness is central to the 5-factor model conceptualization of dependency. However, 4 meta-analyses of the relationship of agreeableness with dependency have failed to identify a consistent relationship. It was the hypothesis of the current study that these findings might be due in part to an emphasis on the assessment of adaptive, rather than maladaptive, variants of agreeableness. This hypothesis was tested by using experimentally altered NEO Personality Inventory—Revised (Costa & McCrae, 1992) items that were reversed with respect to their implications for maladaptiveness. The predicted correlations were confirmed with the experimentally altered version with measures of dependent personality disorder, measures of trait dependency (including 2 measures of adaptive dependency), and measures of dependency from alternative dimensional models of personality disorder. The theoretical implications of the findings and suggestions for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)