Toll-managed lanes: A simplified benefit-cost analysis of seven US projects

Toll managed lanes are expressway lanes where tolls are used—often in combination with preferred access for high occupancy vehicles and other special traffic management techniques—to improve the highway's capacity, speed or reliability. Such lanes have become popular with transportation policymakers as a way of maintaining free-flowing traffic on certain sections of the highway while also, in some cases, financing the construction of new lanes in congested urban areas. This study examines whether toll-managed lanes are as beneficial as they are popular. The heart of the analysis is the application of a simplified social benefit-cost analysis (BCA) to seven projects. In brief, our results paint a complicated picture of toll-managed lane efficacy. Only two of the seven projects have benefit-cost (B/C) ratios above 1.0 using our base case assumptions about the value of travel time saved and the discount rate, although three others approach or exceed 1.0 with more optimistic but plausible assumptions. The most successful generate not only a significant savings of around 4–5 min per trip for motorists who switch to the managed lane but also smaller per-trip savings for the large majority of motorists who continue to use the general-purpose lanes. It is important to acknowledge, however, that these calculations depend upon some uncertain assumptions about the value of travel time savings and improved reliability

Toll-managed lane pioneers: Lessons from five US states

Toll-managed lanes have become an increasingly popular technique among transportation policymakers for managing congestion on existing highways and, in some cases, financing the construction of new lanes in congested urban corridors. Although growing in popularity, the adoption of these facilities is concentrated in five states: Texas, California, Colorado, Minnesota, and Florida. This paper examines the adoption and utilization of toll-managed lanes in these pioneer states. Using archival, case-based research, our analysis suggests that the adoption of toll-managed lanes was driven by a combination of factors, including rapid population growth, near or above average growth in vehicle miles traveled (VMT), and insufficient gas tax funding for transportation investments. Implementation was also generally similar across states but some of the pioneers delegated the management of their toll-managed lane programs to special regional highway authorities while others used state highway agencies

The Conformal Anomaly of M5-Branes

We show that the conformal anomaly for N M5-branes grows like $N^3$. The method we employ relates Coulomb branch interactions in six dimensions to interactions in four dimensions using supersymmetry. This leads to a relation between the six-dimensional conformal anomaly and the conformal anomaly of N=4 Yang-Mills. Along the way, we determine the structure of the four derivative interactions for the toroidally compactified (2,0) theory, while encountering interesting novelties in the structure of the six derivative interactions.Comment: 38 pages, LaTeX; references adde

Crossings, Motzkin paths and Moments

Kasraoui, Stanton and Zeng, and Kim, Stanton and Zeng introduced certain $q$-analogues of Laguerre and Charlier polynomials. The moments of these orthogonal polynomials have combinatorial models in terms of crossings in permutations and set partitions. The aim of this article is to prove simple formulas for the moments of the $q$-Laguerre and the $q$-Charlier polynomials, in the style of the Touchard-Riordan formula (which gives the moments of some $q$-Hermite polynomials, and also the distribution of crossings in matchings). Our method mainly consists in the enumeration of weighted Motzkin paths, which are naturally associated with the moments. Some steps are bijective, in particular we describe a decomposition of paths which generalises a previous construction of Penaud for the case of the Touchard-Riordan formula. There are also some non-bijective steps using basic hypergeometric series, and continued fractions or, alternatively, functional equations.Comment: 21 page

Collapsing glomerulopathy in sickle cell disease: a case report

<p>Abstract</p> <p>Introduction</p> <p>Sickle cell disease has been associated with many renal structural and functional abnormalities. Collapsing glomerulopathy or the collapsing variant of focal segmental glomerulosclerosis is a rare clinicopathologic entity in patients with sickle cell disease that requires timely diagnosis and aggressive management.</p> <p>Case presentation</p> <p>In this case report we describe a 21-year-old African-American woman with a medical history of significant sickle cell disease and asthma. She was admitted for pain, decreased urine output, bilateral leg swelling and reported weight gain. During her period of hospitalisation she developed acute renal failure requiring dialysis. Further investigation revealed the collapsing variant of focal segmental glomerulosclerosis.</p> <p>Conclusions</p> <p>Although focal segmental glomerulosclerosis is a common feature of sickle cell nephropathy, the collapsing variant of focal segmental glomerulosclerosis or collapsing glomerulopathy has been rarely documented. Even when other risk factors are controlled, collapsing glomerulopathy has a very poor prognosis. This is a rare case of a patient with massive proteinuria presenting as acute renal failure with a very poor response to corticosteroids and a much faster rate of progression to end-stage renal disease.</p

Pathophysiology of focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is a major cause of idiopathic steroid-resistant nephrotic syndrome (SRNS) and end-stage kidney disease (ESKD). In recent years, animal models and studies of familial forms of nephrotic syndrome helped elucidate some mechanisms of podocyte injury and disease progression in FSGS. This article reviews some of the experimental and clinical data on the pathophysiology of FSGS

Cardiometabolic risk factors and quality of life in severely obese children and adolescents in the Netherlands

BACKGROUND: The prevalence of severe obesity in children and adolescents is increasing. However, little is known about cardiometabolic risk factors and quality of life of children with severe obesity.Therefore, the aim of this study was to assess the demographic characteristics and the prevalence of cardiometabolic risk factors and quality of life in severely obese children and adolescents undergoing intensive inpatient treatment for obesity. METHODS: Data were collected between August 2009 and April 2011 on 16 children (8-13y) and 64 adolescents (13-19y) with severe obesity (SDS-BMI >= 3.0 or SDS-BMI >= 2.3 and comorbidity) participating in an RCT evaluating two intensive inpatient treatment programs for obesity. Demographic, anthropometric, clinical characteristics and two components of the EuroQol for the assessment of quality of life are described. RESULTS: Eighty percent of participants in this study had at least one cardiometabolic risk factor in addition to severe obesity. Low HDL-cholesterol and hypertension were most prevalent (65.0% respectively 31.2%). The highest significant correlations were found between SDS-BMI and SDS-waist circumference, fasting plasma insulin and HOMA-IR (correlation coefficients respectively 0.80, 0.49, and 0.48). With regard to quality of life, the mean utility score of the participants was 0.79 on a scale of 0.0 to 1.0 on the EuroQol questionnaire and their mean individual valuation was 69.1 on a scale of 0 to100. CONCLUSION: Cardiometabolic risk factors are already highly prevalent in this group of severely obese children and adolescents. The score of 69.1 found for quality of life in this study suggests that participants experience important limitations in their quality of life. However, quality of life is not associated with the prevalence of cardiometabolic risk factors. TRIAL REGISTRATION: Netherlands Trial Register (NTR1678, registered 20-Feb-2009)

Intra-gastric balloon as an adjunct to lifestyle support in severely obese adolescents; Impact on weight, physical activity, cardio-respiratory fitness and psychosocial wellbeing.

BACKGROUND: Severe adolescent obesity (BMI>99.6th centile) is a significant public health challenge. Current non-invasive treatments, including community-based lifestyle interventions, are often of limited effectiveness in this population, with NICE guidelines suggesting the use of bariatric surgery as the last line of treatment (NICE, 2013). Health professionals are understandably reluctant to commission bariatric surgery and as an alternative, the use of an intra-gastric balloon as an adjunct to a lifestyle programme might offer a reversible, potentially safer and less invasive option. OBJECTIVES: Explore the use of an intra-gastric balloon as an adjunct to a lifestyle support programme, to promote weight loss in severely obese adolescents. Outcomes included Weight loss, Waist and Hip measurements, psychosocial outcomes including health related quality of life and physical self-perceptions, physical activity and cardiorespiratory fitness. METHOD: Non-randomised pilot study. Results: 12 severely obese adolescents (5 males, 7 females; mean age 15yrs; BMI >3.5 s.d.; puberty stage 4 or more) and their families were recruited. Mean weight loss at 12 months (n=9) was 3.05 kg±14.69; d=0.002, P=0.550, and a BMI Z-score (n=12) change of 0.2 s.d.; d=0.7, P=0.002 was observed at 6 months with a large effect, but was not sustained at 12 months (mean change 0.1 s.d.; d=0.3, P=0.146 ) At 24 months (n=10) there was a weight gain from baseline of +9.9 kg±1.21 (d=0.4; P=0.433). Adolescent and parent HRQoL scores exceeded the minimal clinical important difference between baseline and 12 months for all domains but showed some decline at 24 months. CONCLUSION: An intra-gastric balloon as an adjunct to a lifestyle support programme represents a safe and well tolerated treatment approach in severely obese adolescents, with short-term effects on weight change. Improvements in psychosocial health, physical activity and cardiorespiratory fitness were maintained at 12 months, with varying results at 24 months

Proteomic identification and characterization of hepatic glyoxalase 1 dysregulation in non-alcoholic fatty liver disease

Background: Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. However, its molecular pathogenesis is incompletely characterized and clinical biomarkers remain scarce. The aims of these experiments were to identify and characterize liver protein alterations in an animal model of early, diet-related, liver injury and to assess novel candidate biomarkers in NAFLD patients. Methods: Liver membrane and cytosolic protein fractions from high fat fed apolipoprotein E knockout (ApoE−/−) animals were analyzed by quantitative proteomics, utilizing isobaric tags for relative and absolute quantitation (iTRAQ) combined with nano-liquid chromatography and tandem mass spectrometry (nLC-MS/MS). Differential protein expression was confirmed independently by immunoblotting and immunohistochemistry in both murine tissue and biopsies from paediatric NAFLD patients. Candidate biomarkers were analyzed by enzyme-linked immunosorbent assay in serum from adult NAFLD patients. Results: Through proteomic profiling, we identified decreased expression of hepatic glyoxalase 1 (GLO1) in a murine model. GLO1 protein expression was also found altered in tissue biopsies from paediatric NAFLD patients. In vitro experiments demonstrated that, in response to lipid loading in hepatocytes, GLO1 is first hyperacetylated then ubiquitinated and degraded, leading to an increase in reactive methylglyoxal. In a cohort of 59 biopsy-confirmed adult NAFLD patients, increased serum levels of the primary methylglyoxal-derived advanced glycation endproduct, hydroimidazolone (MG-H1) were significantly correlated with body mass index (r = 0.520, p < 0.0001). Conclusion: Collectively these results demonstrate the dysregulation of GLO1 in NAFLD and implicate the acetylation-ubquitination degradation pathway as the functional mechanism. Further investigation of the role of GLO1 in the molecular pathogenesis of NAFLD is warranted. Keywords: Non-alcoholic fatty liver disease, Glyoxalase, Methylglyoxal, Proteomics, iTRA