Quantification and Evaluation of Long-term Draindown and Its Influence on the Raveling Susceptibility of Open-graded Friction Course

A porous pavement is a type of sustainable pavement that allows stormwater to infiltrate through the pavement into the natural soil bed. An open-graded friction course (OGFC) is a type of porous asphalt mixture that is commonly used as a wearing course typically having a thickness less than 1.5 inches that is constructed over a conventional asphalt surface. This porous wearing course is used to improve the frictional resistance of pavements and minimize hydroplaning on highways. Raveling is a defect commonly seen in OGFC because of the limited amount of fine aggregates in the mix. This reduction in fine particles from the aggregate matrix causes a reduction in the number of contact points between aggregate particles. This reduction in contact points limits the amount of asphalt binder that is able to bind coarse aggregate particles together. The fewer the contact points between aggregate particles; the more likely raveling is to occur on the surface of the pavement (Shaowen and Shanshan, 2011). Previous studies have been conducted on the draindown that occurs during production and hauling of the asphalt binder due to gravitational forces. However, only a few studies have been conducted on the draindown of asphalt binder after installation, over the service life of the pavement. For the purpose of this research study, “long-term draindown†is defined as the downward migration of asphalt binder through the pore structure of an open graded friction course over the service life of the structure after construction. OGFC can also exhibit clogging of the pore structure caused by the gravity-induced draindown (long-time draindown) of asphalt binder from the top to the bottom of the OGFC pavement layer over the life of the pavement. This can cause a reduction in the binder film thickness surrounding the aggregate particles near the surface and potentially lead to an increase in the raveling susceptibility of the OGFC mix design while clogging the accessible air voids of the structure. The decrease in binder thickness surrounding the aggregate particles and oxidation of the remaining binder film near the surface of the pavement can lead to an increase in raveling susceptibility of OGFC. This research study evaluated and quantified long-term draindown and its influence on the raveling susceptibility of OGFC. In order to effectively evaluate the effects of long-term draindown on the raveling susceptibility of OGFC and identify the underlying mechanism; new laboratory test methods were designed and compared to the existing test method that is currently used to evaluate the raveling susceptibility of OGFC. The new laboratory test methods focused on simulating the forces commonly applied to the surface of OGFC during its service life and showed more of a correlation to the direct shear and indirect tensile strength tests. This indicates that the two new test methods show more of a cohesive failure with minimal fracturing of the aggregate particles compared to the existing test method (Cantabro). The long-term draindown was quantified using image analysis and a Draindown Factor [DF] was calculated. The DF indicated that long-term draindown does have an influence on the raveling susceptibility of the surface of OGFC mixture. The mixture becomes more susceptible to raveling as draindown increases (i.e., higher the DF)

Life interrupted and life regained? Coping with stroke at a young age

Stroke is a leading cause of disability across the developed world, affecting an increasing number of younger people. In this article, we seek to understand the experience of stroke as a disabling life situation among young people and the strategies that they use to recover and cope. Directed content analysis was conducted from interviews with 17 community-dwelling stroke survivors aged 55 years and younger across the United Kingdom. The sample was drawn from a larger maximum variation sample of stroke survivors. Using the sociological concepts of biographical disruption and biographical repair as a guide, excerpts from the interviews pertaining to aspects of the patients’ life that were interrupted, in addition to how they coped with the changes, were selected and analysed. All individuals described an ‘‘altered sense of self,’’ a theme that included loss of identity, family disruption, and/or loss of valued activities. Individuals sought to adapt their sense of self by seeking external support, by restoring normality, and/or through positive reflection. Despite the adapted self that emerged, most individuals continued to experience impairments. While young stroke survivors adapt to their illness over time, they continue to experience impairments and disruptions in their personal and work lives.Aholistic model of rehabilitation that helps individuals regain the capacity for everyday activities related to work, family life, and leisure can begin to address the emotional ramifications of diseases such as stroke, restore wellness, and work towards minimizing the burden felt by family caregivers and children

Life interrupted and life regained? Coping with stroke at a young age

Stroke is a leading cause of disability across the developed world, affecting an increasing number of younger people. In this article, we seek to understand the experience of stroke as a disabling life situation among young people and the strategies that they use to recover and cope. Directed content analysis was conducted from interviews with 17 community-dwelling stroke survivors aged 55 years and younger across the United Kingdom. The sample was drawn from a larger maximum variation sample of stroke survivors. Using the sociological concepts of biographical disruption and biographical repair as a guide, excerpts from the interviews pertaining to aspects of the patients’ life that were interrupted, in addition to how they coped with the changes, were selected and analysed. All individuals described an ‘‘altered sense of self,’’ a theme that included loss of identity, family disruption, and/or loss of valued activities. Individuals sought to adapt their sense of self by seeking external support, by restoring normality, and/or through positive reflection. Despite the adapted self that emerged, most individuals continued to experience impairments. While young stroke survivors adapt to their illness over time, they continue to experience impairments and disruptions in their personal and work lives.Aholistic model of rehabilitation that helps individuals regain the capacity for everyday activities related to work, family life, and leisure can begin to address the emotional ramifications of diseases such as stroke, restore wellness, and work towards minimizing the burden felt by family caregivers and children

Using Small-Area Analysis to Estimate County-Level Racial Disparities in Obesity Demonstrating the Necessity of Targeted Interventions

Data on the national and state levels is often used to inform policy decisions and strategies designed to reduce racial disparities in obesity. Obesity-related health outcomes are realized on the individual level, and policies based on state and national-level data may be inappropriate due to the variations in health outcomes within and between states. To examine county-level variation of obesity within states, we use a small-area analysis technique to fill the void for county-level obesity data by race. Five years of Behavioral Risk Factor Surveillance System data are used to estimate the prevalence of obesity by county, both overall and race-stratified. A modified weighting system is used based on demographics at the county level using 2010 census data. We fit a multilevel reweighted regression model to obtain county-level prevalence estimates by race. We compare the distribution of prevalence estimates of non-Hispanic Blacks to non-Hispanic Whites. For 25 of the 26 states included in our analysis there is a statistically significant difference between within-state county-level average obesity prevalence rates for non-Hispanic Whites and non-Hispanic Blacks. This study provides information needed to target disparities interventions and resources to the local areas with greatest need; it also identifies the necessity of doing so

Development and implementation of the Ontario Stroke System: the use of evidence

<b>Introduction</b><br> The Ontario Stroke System was developed to enhance the quality and continuity of stroke care provided across the care continuum. <br><b>Research Objective</b> <br> To identify the role evidence played in the development and implementation of the Ontario Stroke System. <br><b><title>Methods</b> This study employed a qualitative case study design. In-depth interviews were conducted with six members of the Ontario Stroke System provincial steering committee. Nine focus groups were conducted with: Regional Program Managers, Regional Education Coordinators, and seven acute care teams. To supplement these findings interviews were conducted with eight individuals knowledgeable about national and international models of integrated service delivery.<br> <b>Results</b><br> Our analyses identified six themes. The first four themes highlight the use of evidence to support the process of system development and implementation including: 1) informing system development; 2) mobilizing governmental support; 3) getting the system up and running; and 4) integrating services across the continuum of care. The final two themes describe the foundation required to support this process: 1) human capacity and 2) mechanisms to share evidence. <br> <b>Conclusion</b><br> This study provides guidance to support the development and implementation of evidence-based models of integrated service delivery

High-resolution global maps of tidal flat ecosystems from 1984 to 2019

Assessments of the status of tidal flats, one of the most extensive coastal ecosystems, have been hampered by a lack of data on their global distribution and change. Here we present globally consistent, spatially-explicit data of the occurrence of tidal flats, defined as sand, rock or mud flats that undergo regular tidal inundation. More than 1.3 million Landsat images were processed to 54 composite metrics for twelve 3-year periods, spanning four decades (1984–1986 to 2017–2019). The composite metrics were used as predictor variables in a machine-learning classification trained with more than 10,000 globally distributed training samples. We assessed accuracy of the classification with 1,348 stratified random samples across the mapped area, which indicated overall map accuracies of 82.2% (80.0–84.3%, 95% confidence interval) and 86.1% (84.2–86.8%, 95% CI) for version 1.1 and 1.2 of the data, respectively. We expect these maps will provide a means to measure and monitor a range of processes that are affecting coastal ecosystems, including the impacts of human population growth and sea level rise

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder