Liability Waivers and Participation Rates in Youth Sports: An Empirical Investigation

In this Article, we offer an empirical analysis of the relationship between liability waivers signed by parents and participation rates in youth sports. Specifically, we explore whether waiver enforcement is statistically associated with increased participation in youth sports. Our study finds no significant evidence of such a relationship. The impetus for this investigation comes from an experience shared by parents all over the United States. A parent enrolls his minor child in a sports activity like a school team, club sport, skating party, or tennis camp. Organizers condition the child’s participation on the parent signing a liability waiver in the organizers’ favor. Legally, doctrinal reasons exist to doubt the enforceability of these releases. Despite these concerns, many courts enforce youth sports releases. Although these decisions could be justified on grounds of parental autonomy and freedom of contract, the primary argument favoring enforcement asserts that youth sports releases serve minors’ interests, even at the cost of greater uncompensated injury. Without enforceable waivers, youth sports providers may reduce their offerings or go out of business to avoid tort liability risks. Conversely, allowing youth sports providers to avoid liability increases youth sports opportunities, and youth sports participation by extension, which confers benefits on youths outweighing any increased risk of uncompensated injury. This policy argument might be right. However, it is plausible only if youth sports participation increases when courts enforce exculpatory agreements signed by parents. However, no prior study has tested whether enforcing youth sports releases has the hypothesized effect. The study described here therefore provides valuable information about the persuasiveness of arguments on either side of a split in contract and tort law. We conducted our study by applying a linear mixed effects regression analysis6 to a dataset containing information about high school sports participation rates and the fifty states’ law including the District of Columbia from 1988-2014. This allowed us to test for an association between enforcing youth sports releases and high school sports participation rates. Our analysis uncovered no statistically significant association. This implies that the major argument given by courts for enforcing youth sports releases lacks empirical support

Initial Investigation on the Impact of In Situ Hydrogen Plasma Exposure to the Interface Between Molecular Beam Epitaxially Grown P-Ga_0.7In_0.3Sb (100) and Thermal Atomic Layer Deposited (ALD) Al₂O₃

This work presents, to the best of the authors knowledge, the first experimental findings on the impact of in situ H<sub>2</sub> plasma exposure to the electrical properties of the interface between p-type Ga<sub>0.7</sub>In<sub>0.3</sub>Sb and atomic layer deposited Al<sub>2</sub>O<sub>3</sub>. The effects of trimethyl aluminium (TMA) exposure prior to Al<sub>2</sub>O<sub>3</sub> deposition, and of a post gate metal forming gas anneal (FGA) are also investigated. The control sample, which was subjected to an ex situ HCl clean prior to ALD only, demonstrated a capacitance modulation of 36.29 % before FGA. This degraded for samples exposed to the H<sub>2</sub> plasma for all plasma powers investigated. TMA exposure offered no improvement, and significantly increased the frequency dispersion in accumulation for all samples. A post gate metal FGA at 350 °C for 15 minutes was found to substantially improve the interface quality, with the capacitance modulation, frequency dispersion in accumulation and dC/dV improving by as much as 190 %, 91 %, and 170 % respectively

Machine Learning Outperforms ACC / AHA CVD Risk Calculator in MESA.

Background Studies have demonstrated that the current US guidelines based on American College of Cardiology/American Heart Association (ACC/AHA) Pooled Cohort Equations Risk Calculator may underestimate risk of atherosclerotic cardiovascular disease ( CVD ) in certain high-risk individuals, therefore missing opportunities for intensive therapy and preventing CVD events. Similarly, the guidelines may overestimate risk in low risk populations resulting in unnecessary statin therapy. We used Machine Learning ( ML ) to tackle this problem. Methods and Results We developed a ML Risk Calculator based on Support Vector Machines ( SVM s) using a 13-year follow up data set from MESA (the Multi-Ethnic Study of Atherosclerosis) of 6459 participants who were atherosclerotic CVD-free at baseline. We provided identical input to both risk calculators and compared their performance. We then used the FLEMENGHO study (the Flemish Study of Environment, Genes and Health Outcomes) to validate the model in an external cohort. ACC / AHA Risk Calculator, based on 7.5% 10-year risk threshold, recommended statin to 46.0%. Despite this high proportion, 23.8% of the 480 "Hard CVD " events occurred in those not recommended statin, resulting in sensitivity 0.76, specificity 0.56, and AUC 0.71. In contrast, ML Risk Calculator recommended only 11.4% to take statin, and only 14.4% of "Hard CVD " events occurred in those not recommended statin, resulting in sensitivity 0.86, specificity 0.95, and AUC 0.92. Similar results were found for prediction of "All CVD " events. Conclusions The ML Risk Calculator outperformed the ACC/AHA Risk Calculator by recommending less drug therapy, yet missing fewer events. Additional studies are underway to validate the ML model in other cohorts and to explore its ability in short-term CVD risk prediction

Transposase mapping identifies the genomic targets of BAP1 in uveal melanoma

Table summarizing the RNA-seq results. Differential gene expression results in BAP1-knockdown compared to control OCM-1A cells are shown from the RNA-seq data. Each row gives the unique Ensembl identifier, gene name, and description for each gene, as well as the log of the fold change (logFC), average expression, adjusted p-value, and linear fold change. (XLSX 1392 kb

Gamification in transport interventions: Another way to improve travel behavioural change

Gamification is dramatically transforming how behaviour change interventions are delivered. The design of gaming products in the field of transport, a field which is perceived as having derived demand, is largely underdeveloped. This paper explores gamification in the context of transport, proposes a conceptual theoretical framework that explains why and how gamification may be designed and evaluated, and synthesises current practice regarding the range of interventions offered thus far. The conclusions identify strategies and implications for the improvement to existing schemes as well as guidance for future research into gamification

Gentrification and Displacement in the San Francisco Bay Area: A Comparison of Measurement Approaches.

Gentrification may play an important role in influencing health outcomes, but few studies have examined these associations. One major barrier to producing empirical evidence to establish this link is that there is little consensus on how to measure gentrification. To address this barrier, we compared three gentrification classification methodologies in relation to their ability to identify neighborhood gentrification in nine San Francisco Bay Area counties: the Freeman method, the Landis method, and the Urban Displacement Project (UDP) Regional Early Warning System. In the 1580 census tracts, 43% of the population had a bachelor's degree or higher. The average median household income was $79,671 in 2013. A comparison of gentrification methodologies revealed that the Landis and Freeman methodologies characterized the vast majority of census tracts as stable, and only 5.2% and 6.1% of tracts as gentrifying. UDP characterized 46.7% of tracts at risk, undergoing, or experiencing advanced stages of gentrification and displacement. There was substantial variation in the geographic location of tracts identified as gentrifying across methods. Given the variation in characterizations of gentrification across measures, studies evaluating associations between gentrification and health should consider using multiple measures of gentrification to examine the robustness of the study findings across measures

Ultrasound detection using polymer microring optical resonator

Application of polymer waveguide microring resonators for high-frequency ultrasound detection is presented. The device consists of a microring optical resonator coupled to a straight optical waveguide which serves as input and output ports. Acoustic waves irradiating the ring waveguide induce strain modifying the waveguide cross section. As a consequence, the effective refractive index of optical waves propagating along the ring is modified. The sharp wavelength dependence of the high QQ-factor resonator enhances the optical response to acoustic strain. High sensitivity is demonstrated experimentally in detecting broadband ultrasound pulses from a 10 MHz10 MHz transducer. Methods of extending the technique to form multi-element ultrasonic arrays for imaging applications are proposed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70498/2/APPLAB-85-22-5418-1.pd

Spatial variations of the effects of bus rapid transit on residential property values

Public transport investment is normally targeted at increasing accessibility which land rent theory identifies will increase land values. There is clear interest in how much land values increase to establish whether there is sufficient uplift to capture to help pay or contribute to investment plans. Identifying uplift for residential land has been well studied in the context of new light rail systems and bus rapid transit (BRT) systems in developing countries but there is little evidence for BRT in developed countries. This paper has two objectives. First, to examine long term impact of BRT in a developed world context in Brisbane, Australia as studies in Sydney, Australia, suggest little uplift in comparison to developing world contexts but this maybe from its isolated suburban location in contrast to the extended BRT network in Brisbane. Second, to consider the spatial distribution of uplift which is an essential pre-requisite to understanding the distributional impact if uplift is used to contribute to infrastructure provision. Spatial modelling is used to examine the accessibility impacts of the BRT and this is followed by Geographical Weighted Regression, used to examine the spatial distribution of accessibility. The results show there is greater uplift in Brisbane, as compared to Sydney, Australia which is likely due to the greater network coverage of BRT in Brisbane and a relative lack of rail based competition

Strain-stiffening gels based on latent crosslinking

Gels are an increasingly important class of soft materials with applications ranging from regenerative medicine to commodity materials. A major drawback of gels is their relative mechanical weakness, which worsens further under strain. We report a new class of responsive gels with latent crosslinking moieties that exhibit strain-stiffening behavior. This property results from the lability of disulfides, initially isolated in a protected state, then activated to crosslink on-demand. The active thiol groups are induced to form inter-chain crosslinks when subjected to mechanical compression, resulting in a gel that strengthens under strain. Molecular shielding design elements regulate the strain-sensitivity and spontaneous crosslinking tendencies of the polymer network. These strain-responsive gels represent a rational design of new advanced materials with on-demand stiffening properties with potential applications in elastomers, adhesives, foams, films, and fibers