The influence of sun loading on the visibility of clear-lens turn signals

There is some concern that turn signal lamps with clear outer lenses make it difficult in bright, sunny conditions to decide whether the signal is on or not. Two studies were performed. The first study was a survey of current practice in the U.S. with regard to the use of clear-lens turn signal lamps. The main results are that clear outer lenses on rear turn signal lamps are used in about 28% of all vehicle models, while the corresponding percentage for front turn signal lamps is about 70%. The second study photometrically evaluated, under bright, sunny conditions, both luminance contrast and color contrast between the on and off states for turn signal lamps that use either an amber lens or a clear lens. The results indicate that luminance contrast between the on and off states is greater for lamps using an amber lens. On the other hand, the results indicate that color contrast between the on and off states is greater for lamps using a clear lens. Because luminance contrast is likely to be the primary variable influencing driver performance, these results suggest that using clear-lens turn signal lamps is likely to make it more difficult to determine, in bright, sunny conditions, whether the signal is on or not. However, the magnitude of the decrement in real-world performance with clear-lens signal lamps remains to be ascertained.Michigan University, Ann Arbor, Industry Affiliation Program for Human Factors in Transportation Safetyhttp://deepblue.lib.umich.edu/bitstream/2027.42/49364/1/UMTRI-98-2.pd

Macromolecular theory of solvation and structure in mixtures of colloids and polymers

The structural and thermodynamic properties of mixtures of colloidal spheres and non-adsorbing polymer chains are studied within a novel general two-component macromolecular liquid state approach applicable for all size asymmetry ratios. The dilute limits, when one of the components is at infinite dilution but the other concentrated, are presented and compared to field theory and models which replace polymer coils with spheres. Whereas the derived analytical results compare well, qualitatively and quantitatively, with mean-field scaling laws where available, important differences from ``effective sphere'' approaches are found for large polymer sizes or semi-dilute concentrations.Comment: 23 pages, 10 figure

Family Outcomes After the Pediatric Intensive Care Unit: A Scoping Review

Background: Intensivists are increasingly attuned to the post-discharge outcomes experienced by families because patient recovery and family outcomes are interdependent after childhood critical illness. In this scoping review of international contemporary literature, we describe the evidence of family effects and functioning post-PICU as well as outcome measures used in order to identify strengths and weaknesses in the literature.Methods: We reviewed all articles published between 1970 and 2017 in PubMed, EMBASE, PsycINFO, Cumulative Index of Nursing and Allied Health Literature (CINAHL), or the Cochrane Controlled Trials Registry. Our search used a combination of terms for the concept of “critical care/illness” combined with additional terms for the pre-specified domains of social, cognitive, emotional, physical, health-related quality of life (HRQL), and family functioning.Results: We identified 71 articles reporting on the post-PICU experience of more than 2,400 parents and 3,600 families of PICU survivors in 8 countries. These articles used 101 different metrics to assess the various aspects of family outcomes; 34 articles also included open-ended interviews. Overall, most families experienced significant disruption in at least 5 out of 6 of our family outcomes subdomains, with themes of decline in mental health, physical health, family cohesion, and family finances identified. Almost all articles represented relatively small, single-center or disease-specific observational studies. There was disproportionate representation of families of higher socioeconomic status and Caucasian race, and there was much more data about mothers compared to fathers. There was also very limited information regarding outcomes for siblings and extended family members after a child’s PICU stay. Conclusions: Significant opportunities remain for research exploring family functioning after PICU discharge. We recommend that future work include more diverse populations with respect to the critically ill child as well as family characteristics, include more intervention studies, and enrich existing knowledge about outcomes for siblings and extended family

Mental Health and School Functioning for Girls in the Child Welfare System : the Mediating Role of Future Orientation and School Engagement

This study investigated the association between mental health problems and academic and behavioral school functioning for adolescent girls in the child welfare system and determined whether school engagement and future orientation meditated the relationship. Participants were 231 girls aged between 12 and 19 who had been involved with the child welfare system. Results indicated that 39% of girls reported depressive symptoms in the clinical range and 54% reported posttraumatic symptoms in the clinical range. The most common school functioning problems reported were failing a class (41%) and physical fights with other students (35%). Participants reported a mean number of 1.7 school functioning problems. Higher levels of depression and PTSD were significantly associated with more school functioning problems. School engagement fully mediated the relationship between depression and school functioning and between PTSD and school functioning, both models controlling for age, race, and placement stability. Future orientation was not significantly associated with school functioning problems at the bivariate level. Findings suggest that school engagement is a potentially modifiable target for interventions aiming to ameliorate the negative influence of mental health problems on school functioning for adolescent girls with histories of abuse or neglect

A Controversy That Has Been Tough to Swallow: Is the Treatment of Achalasia Now Digested?

Esophageal achalasia is a rare neurodegenerative disease of the esophagus and the lower esophageal sphincter that presents within a spectrum of disease severity related to progressive pathological changes, most commonly resulting in dysphagia. The pathophysiology of achalasia is still incompletely understood, but recent evidence suggests that degeneration of the postganglionic inhibitory nerves of the myenteric plexus could be due to an infectious or autoimmune mechanism, and nitric oxide is the neurotransmitter affected. Current treatment of achalasia is directed at palliation of symptoms. Therapies include pharmacological therapy, endoscopic injection of botulinum toxin, endoscopic dilation, and surgery. Until the late 1980s, endoscopic dilation was the first line of therapy. The advent of safe and effective minimally invasive surgical techniques in the early 1990s paved the way for the introduction of laparoscopic myotomy. This review will discuss the most up-to-date information regarding the pathophysiology, diagnosis, and treatment of achalasia, including a historical perspective. The laparoscopic Heller myotomy with partial fundoplication performed at an experienced center is currently the first line of therapy because it offers a low complication rate, the most durable symptom relief, and the lowest incidence of postoperative gastroesophageal reflux