Methods Matter: Beating the Backward Clock

In “Beat the (Backward) Clock,” we argued that John Williams and Neil Sinhababu’s Backward Clock Case fails to be a counterexample to Robert Nozick’s or Fred Dretske’s Theories of Knowledge. Williams’ reply to our paper, “There’s Nothing to Beat a Backward Clock: A Rejoinder to Adams, Barker and Clarke,” is a further attempt to defend their counterexample against a range of objections. In this paper, we argue that, despite the number and length of footnotes, Williams is still wrong

Beat the (Backward) Clock

In a recent very interesting and important challenge to tracking theories of knowledge, Williams & Sinhababu claim to have devised a counter-example to tracking theories of knowledge of a sort that escapes the defense of those theories by Adams & Clarke. In this paper we will explain why this is not true. Tracking theories are not undermined by the example of the backward clock, as interesting as the case is

Collisional deactivation of highly vibrationally excited pyrazine

The collisional deactivation of vibrationally excited pyrazine (C4N2H4) in the electronic ground state by 19 collider gases was studied using the time‐resolved infrared fluorescence (IRF) technique. The pyrazine was photoexcited with a 308 nm laser and its vibrational deactivation was monitored following rapid radiationless transitions to produce vibrationally excited molecules in the electronic ground state. The IRF data were analyzed by a simple approximate inversion method, as well as with full collisional master equation simulations. The average energies transferred in deactivating collisions (〈ΔE〉d) exhibit a near‐linear dependence on vibrational energy at lower energies and less dependence at higher energies. The deactivation of ground state pyrazine was found to be similar to that of ground state benzene [J. R. Barker and B. M. Toselli, Int. Rev. Phys. Chem. 12, 305 (1990)], but it is strikingly different from the deactivation of triplet state pyrazine [T. J. Bevilacqua and R. B. Weisman, J. Chem. Phys. 98, 6316 (1993)]. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70797/2/JCPSA6-105-4-1383-1.pd

Temperature effects in the collisional deactivation of highly vibrationally excited pyrazine by unexcited pyrazine

Time‐dependent infrared fluorescence (IRF) from the C–H fundamental and overtone bands was used to monitor the vibrational deactivation (by unexcited pyrazine) of pyrazine excited at 308 nm with a pulsed laser. The 1‐color and 2‐color IRF results were modeled with collisional master equation calculations in order to determine the temperature dependence of the energy transfer parameters. The experimental data cannot be modeled without invoking a biexponential collision step size distribution, which implies that ‘‘super collisions’’ are significant. The results show that the energy transfer parameters are essentially constant at temperatures greater than the Lennard–Jones well depth, but at lower temperatures, energy transfer is enhanced. It is likely that vibration–vibration energy transfer dominates in this system. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70488/2/JCPSA6-105-8-3012-1.pd

3-Dimensional Scanning to Determine Body Volume and Composition With and Without a Wetsuit

Wetsuits are designed to improve swimming performance by providing increased buoyant forces, reduced drag forces, and compressive forces on the body. Recently, 3-D scanning technology (2015 Structure Scanner, Occipital) has been used to measure body volume, and may provide an alternative method to obtaining body composition. Purpose: Therefore, the purpose of this study is to use 3-D scanning to measure and compare body volume with and without a wet suit. Combined with mass, volume from 3-D scanning will provide density calculations for body composition analysis. A secondary purpose of this study is to measure the difference in body composition with and without a wetsuit. Methods: The Institutional Review Board has recently approved the study and data collection has started; therefore, no data are presented in this abstract. Participants will be 3-D scanned with and without a wetsuit (Company), followed by BodPod (COSMED) measurements with and without the wetsuit. Following measurements, the 3-D scan will be used to calculate volume using MeshLab Software (Company). 2x2 mixed-factor ANOVA will be run to analyze the differences between wetsuit conditions, and between measurement methods (3D Scan vs BodPod). By comparing measurements of body volume and calculations of body composition with and without a wetsuit, the validity of the 3-D scanning technique will be determined and this might lead to the development of empirically determined wetsuit fit criteria

Corrigendum: A content analysis of tobacco and alcohol audio-visual content in a sample of UK reality TV programmes

Exposure to tobacco and alcohol content in audio-visual media is a risk factor for smoking and alcohol use in young people. We report an analysis of tobacco and alcohol content, and estimates of population exposure to this content, in a sample of reality television programmes broadcast in the UK. We used 1-minute interval coding to quantify tobacco and alcohol content in all episodes of five reality TV programmes aired between January and August 2018 (Celebrity Big Brother; Made in Chelsea; The Only Way is Essex; Geordie Shore and Love Island), and estimated population exposure using viewing data and UK population estimates. We coded 5219 intervals from 112 episodes. Tobacco content appeared in 110 (2%) intervals in 20 (18%) episodes, and alcohol in 2212 (42%) intervals and in all episodes. The programmes delivered approximately 214 million tobacco gross impressions to the UK population, including 47.37 million to children; and for alcohol, 4.9 billion and 580 million respectively. Tobacco, and especially alcohol, content is common in reality TV. The popularity of these programmes with young people, and consequent exposure to tobacco and alcohol imagery, represents a potentially major driver of smoking and alcohol consumption

Incidence and public health burden of sunburn among beachgoers in the United States.

The beach environment creates many barriers to effective sun protection, putting beachgoers at risk for sunburn, a well-established risk factor for skin cancer. Our objective was to estimate incidence of sunburn among beachgoers and evaluate the relationship between sunburn incidence and sun-protective behaviors. A secondary analysis, of prospective cohorts at 12 locations within the U.S. from 2003 to 2009 (n = 75,614), were pooled to evaluate sunburn incidence 10-12 days after the beach visit. Behavioral and environmental conditions were cross-tabulated with sunburn incidence. Multivariable logistic regression was used to estimate the association between new sunburn and sun-protective behaviors. Overall, 13.1% of beachgoers reported sunburn. Those aged 13-18 years (16.5%), whites (16.0%), and those at beach locations along the Eastern Seaboard (16.1%), had the highest incidence of sunburn. For those spending ≥5 h in the sun, the use of multiple types of sun protection reduced odds of sunburn by 55% relative to those who used no sun protection (Odds Ratio = 0.45 (95% Confidence Interval:0.27-0.77)) after adjusting for skin type, age, and race. Acute health effects of sunburn tend to be mild and self-limiting, but potential long-term health consequences are more serious and costly. Efforts to encourage and support proper sun-protective behaviors, and increase access to shade, protective clothing, and sunscreen, can help prevent sunburn and reduce skin cancer risk among beachgoers