Do Transportation Network Companies Decrease or Increase Congestion?

This research examines whether transportation network companies (TNCs), such as Uber and Lyft, live up to their stated vision of reducing congestion in major cities. Existing research has produced conflicting results and has been hampered by a lack of data. Using data scraped from the application programming interfaces of two TNCs, combined with observed travel time data, we find that contrary to their vision, TNCs are the biggest contributor to growing traffic congestion in San Francisco. Between 2010 and 2016, weekday vehicle hours of delay increased by 62% compared to 22% in a counterfactual 2016 scenario without TNCs. The findings provide insight into expected changes in major cities as TNCs continue to grow, informing decisions about how to integrate TNCs into the existing transportation system

TNCs & Congestion

From the executive summary: This document: Identifies common measures of roadway congestion; Discusses factors that contribute to roadway to congestion; and Quantifies the relative contributions of different factors, including population, employment, road network changes and TNCs, to observed changes in congestion in San Francisco between 2010 and 2016, by location and time of day. The report utilizes a unique TNC trip dataset provided to the Transportation Authority by researchers from Northeastern University in late 2016, as well as INRIX data, a commercial dataset which combines several real-time GPS monitoring sources with data from highway performance monitoring systems. These data are augmented with information on network changes, population changes, and employment changes provided by local and regional planning agencies, which are used as input to the Transportation Authority’s activity-based regional travel demand model SF-CHAMP

Exploring the Neural Correlates of Mindfulness-Based Interventions in Youth

Mindfulness based interventions (MBI) reduce the severity of anxiety and depression among a variety of populations. While the psychological benefits of MBIs are increasingly recognized, less is known about the underlying neural correlates—particularly during childhood and adolescence, a time when many psychopathologies begin to emerge. Here, we provide the first systematic review on the neural correlates of MBI in youth. We reviewed the PubMed database for original articles examining the neural correlates of MBI in youth (0-18 years) leveraging neuroimaging. The search yielded 331 studies, of which 13 were included in the review. These studies comprised 451 participants and were summarized following PRISMA guidelines. Thirteen studies were functional magnetic resonance imaging (n=4 task-based, n=7 resting-state, n=2 graph theory) and two were structural. Most studies (n=10) included non-typically developing adolescents (e.g. familial risk for bipolar disorder) and the remainder were typically developing. Results from the studies were mixed. However, multiple studies reported reduced default mode network (DMN) activity during meditation, increased resting-state connectivity within fronto-parietal and salience networks, and increased fractional anisotropy in various in white matter pathways, following a MBI. Further research is necessary to clarify the diverse ways in which mindfulness affects neural connectivity and structure in both typically developing and non-typically developing youth. This is crucial due to its potential implications for psychopathology, with hyperactivity of the DMN implicated in processes such as rumination and increased risk of depression

Neural Correlates Of Fear Extinction: Investing The Impact Of Puberty And Sex In Children And Adolescents Through Neuroimaging

Fear-based disorders, including anxiety and posttraumatic stress disorder, are more prevalent in females than males. Steroid hormones (e.g., estradiol) are involved in fear extinction learning and later recall—a process implicated in the pathophysiology of fear-based disorders. Fear-based disorders commonly emerge during the transition from childhood to adolescence, a period marked by the onset of puberty and a natural increase of steroid hormones. Here, we examined the effects of puberty, sex, and their interaction on extinction recall and underlying neural circuitry in youth. Eighty-five youth (6-17 years, 46% female) completed a two-day Pavlovian fear extinction paradigm while undergoing functional magnetic resonance imaging. Conditioned fear was measured using unconditioned stimulus expectancy ratings during extinction recall. We examined the effects of biological sex, puberty (early, mid/late), and the sex-by-puberty interaction on expectancy ratings and frontolimbic region activity. There were no significant main effects or interactions of sex-by-puberty on expectancy ratings (p’s\u3e0.05). However, there was a significant sex-by-puberty interaction for activity in the left hippocampus, right hippocampus, and ventromedial prefrontal cortex (p5). Among males, brain activity was higher for early pubertal youth as compared to mid/late pubertal youth. Conversely, in females, frontolimbic activity was lower for early pubertal youth as compared to mid/late pubertal youth. These findings suggest that frontolimbic activation during extinction recall varies by both puberty and sex. This insight can potentially enhance our understanding of sex differences in risk for fear-based disorders and may pave the way for developing novel treatment options

IndEcho study: cohort study investigating birth size, childhood growth and young adult cardiovascular risk factors as predictors of midlife myocardial structure and function in South Asians.

INTRODUCTION: South Asians have high rates of cardiovascular disease (CVD) and its risk factors (hypertension, diabetes, dyslipidaemia and central obesity). Left ventricular (LV) hypertrophy and dysfunction are features of these disorders and important predictors of CVD mortality. Lower birth and infant weight and greater childhood weight gain are associated with increased adult CVD mortality, but there are few data on their relationship to LV function. The IndEcho study will examine associations of birth size, growth during infancy, childhood and adolescence and CVD risk factors in young adulthood with midlife cardiac structure and function in South Asian Indians. METHODS AND ANALYSIS: We propose to study approximately 3000 men and women aged 43-50 years from two birth cohorts established in 1969-1973: the New Delhi Birth Cohort (n=1508) and Vellore Birth Cohort (n=2156). They had serial measurements of weight and height from birth to early adulthood. CVD risk markers (body composition, blood pressure, glucose tolerance and lipids) and lifestyle characteristics (tobacco and alcohol consumption, physical activity, socioeconomic status) were assessed at age ~30 years. Clinical measurements in IndEcho will include anthropometry, blood pressure, biochemistry (glucose, fasting insulin and lipids, urinary albumin/creatinine ratio) and body composition by dual energy X-ray absorptiometry and bioelectrical impedance. Outcomes are LV mass and indices of LV systolic and diastolic function assessed by two-dimensional and Doppler echocardiography, carotid intimal-media thickness and ECG indicators of ischaemia. Regression and conditional growth models, adjusted for potential confounders, will be used to study associations of childhood and young adult exposures with these cardiovascular outcomes. ETHICS AND DISSEMINATION: The study has been approved by the Health Ministry Steering Committee, Government of India and institutional ethics committees of participating centres in India and the University of Southampton, UK. Results will be disseminated through scientific meetings and peer-reviewed journals. TRIAL REGISTRATION NUMBER: ISRCTN13432279; Pre-results