4,228 research outputs found

    Looming motion primes the visuomotor system.

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    A wealth of evidence now shows that human and animal observers display greater sensitivity to objects that move toward them than to objects that remain static or move away. Increased sensitivity in humans is often evidenced by reaction times that increase in rank order from looming, to receding, to static targets. However, it is not clear whether the processing advantage enjoyed by looming motion is mediated by the attention system or the motor system. The present study investigated this by first examining whether sensitivity is to looming motion per se or to certain monocular or binocular cues that constitute stereoscopic motion in depth. None of the cues accounted for the looming advantage. A perceptual measure was then used to examine performance with minimal involvement of the motor system. Results showed that looming and receding motion were equivalent in attracting attention, suggesting that the looming advantage is indeed mediated by the motor system. These findings suggest that although motion itself is sufficient for attentional capture, motion direction can prime motor responses. © 2013 American Psychological Association

    Expanding attributable fraction applications to outcomes wholly attributable to a risk factor

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    The problem central to this document is the estimation of change in disease attributable to an epidemiological exposure variable that stems from a change in the distribution of that variable. We require that both disease and exposure are quantifiable as real numbers, and then ask how to estimate the fraction of disease attributable to exposure, producing the general attributable fraction methodology. After the mathematical framework is in place, we explore the implications of a disease that is wholly attributable to a given risk factor, demonstrate why standard applications of the attributable fractions do not extend, and present general methodological considerations for this case. Finally, we demonstrate the methodology using the example of alcoholic psychoses

    Quantile regression of tobacco tax pass-through in the UK 2013–2019. How have manufacturers passed through tax changes for different tobacco products?

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    Background: The effectiveness of tax increases relies heavily on the tobacco industry passing on such increases to smokers (also referred to as ‘pass-through’). Previous research has found heterogeneous levels of tax pass-through across the market segments of tobacco products available to smokers. This study uses retail sales data to assess the extent to which recent tax changes have been passed on to smokers and whether this varies across the price distribution. Methods: We use panel data quantile regression analysis on Nielsen commercial data of tobacco price and sales in the UK from January 2013 to March 2019 combined with official UK tax rates and inflation to calculate the rate of tax pass-through for factory made (FM) cigarettes and roll your own (RYO) tobacco. Results: Following increases in the specific tax payable on tobacco, we find evidence of overshifting across the price distribution for both FM and RYO. The rate of the overshift in tax increased the more expensive the products were. This was consistent for FM and RYO. Additionally, our findings suggest that the introduction of standardised packaging was not followed by changes in how the tobacco industry responded to tax increases. Conclusions: Following the repeated introduction of increases in specific tobacco tax as well as standardised packaging, we show that the tobacco industry applies techniques to keep the cheapest tobacco cheaper relative to the more expensive products when passing on tax increases to: smokers

    A Thirteenth-Century English Charter at Brock University

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    In the fall of 2008, staff of the Special Collections and Archives of the James A. Gibson library at Brock University in St. Catharines, Ontario, discovered a small, tightly folded, and clearly very old parchment document in a bag in the bottom drawer of a filing cabinet. The document, which had been transferred to the Library from the President’s Office in 1976, was stored without being catalogued, probably because it fell outside the scope of the department’s collection policy. It remained unexamined for over thirty years until early in 2009, when the announcement of its ‘rediscovery’ caused considerable excitement among the Brock University and Niagara communities. Efforts to trace the provenance of the Charter prior to its arrival at Brock University have proven unsuccessful. The document, dated to the mid-thirteenth century, records a grant of land in the village of Clopton in Warwickshire (see further below) by Robert de Clopton to his son William; although some of the individuals and places named in it are known from contemporaneous records, it does not appear to be referred to in secondary sources pertaining to the family, the estate, or the county and, in fact, seems to be completely unknown. The Clopton charter now has the distinction of being the oldest item in the holdings of the James A. Gibson Library at Brock University. This paper offers a description, transcription, translation and preliminary analysis of the document

    The MOND Fundamental Plane

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    Modified Newtonian Dynamics (MOND) has been shown to be able to fit spiral galaxy rotation curves as well as giving a theoretical foundation for empirically determined scaling relations, such as the Tully - Fisher law, without the need for a dark matter halo. As a complementary analysis, one should investigate whether MOND can also reproduce the dynamics of early - type galaxies (ETGs) without dark matter. As a first step, we here show that MOND can indeed fit the observed central velocity dispersion σ0\sigma_0 of a large sample of ETGs assuming a simple MOND interpolating functions and constant anisotropy. We also show that, under some assumptions on the luminosity dependence of the Sersic n parameter and the stellar M/L ratio, MOND predicts a fundamental plane for ETGs : a log - linear relation among the effective radius ReffR_{eff}, σ0\sigma_0 and the mean effective intensity ⟨Ie⟩\langle I_e \rangle. However, we predict a tilt between the observed and the MOND fundamental planes.Comment: 16 pages, 2 figures, 2 tables, accepted for publication on MNRA

    A method for reducing animal use whilst maintaining statistical power in electrophysiological recordings from rodent nerves

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    The stimulus evoked compound action potential, recorded from ex vivo nerve trunks such as the rodent optic and sciatic nerve, is a popular model system used to study aspects of nervous system metabolism. This includes (1) the role of glycogen in supporting axon conduction, (2) the injury mechanisms resulting from metabolic insults, and (3) to test putative benefits of clinically relevant neuroprotective strategies. We demonstrate the benefit of simultaneously recording from pairs of nerves in the same superfusion chamber compared with conventional recordings from single nerves. Experiments carried out on mouse optic and sciatic nerves demonstrate that our new recording configuration decreased the relative standard deviation from samples when compared with recordings from an equivalent number of individually recorded nerves. The new method reduces the number of animals required to produce equivalent Power compared with the existing method, where single nerves are used. Adopting this method leads to increased experimental efficiency and productivity. We demonstrate that reduced animal use and increased Power can be achieved by recording from pairs of rodent nerve trunks simultaneously
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