149 research outputs found

    Urban arterial lane flow distribution: a before and after traffic microsimulation analysis on the effect of implementing new route markings and signage.

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    Urban arterials may not effectively utilize available lanes to move vehicles efficiently as drivers try to establish position along the corridor. This study evaluates lane flow distribution before and after implementing new route markings and overhead signs to utilize existing lanes better. A cellphone-based traffic data service called StreetLight gathered the traffic data used to establish the VISSIM model parameters for simulating current and projected conditions. This study shows that the lane assignment signage and route markers affected the lane flow distribution in the simulation. The simulation indicated the existing condition had average queue lengths of 320.6 meters, average travel times of 389.5 seconds, an average stop delay of 259.6 seconds, and an average lane flow distribution in the right lane of 76.1%. Upon implementing new route markers and sign installations, the projected simulation showed average queue lengths of 39.0 meters, average travel times of 171.4 seconds, an average delay of 92.5 seconds, and an average lane flow distribution in the right lane of 47.4%

    Is College Financial Aid Equitable and Efficient?

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    On Secular Stagnation in the Industrialized World

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    We argue that the economy of the industrialized world taken as a whole is currently – and for the foreseeable future will remain – highly prone to secular stagnation. But for extraordinary fiscal policies, real interest rates would have fallen much more and be far below their current slightly negative level, current and prospective inflation would be further short of the two percent target levels and past and future economic recoveries would be even more sluggish. We start by arguing that, contrary to current practice, neutral real interest rates are best estimated for the bloc of all industrial economies given capital mobility between them and relatively limited fluctuations in their aggregated current account. We show, using standard econometric procedures and looking at direct market indicators of prospective real rates, that neutral real interest rates have declined by at least 300 basis points over the last generation. We argue that these secular movements are in larger part a reflection of changes in saving and investment propensities rather than the safety and liquidity properties of Treasury instruments. We highlight the observation that levels of government debt, the extent of pay-as-you-go old age pensions and the insurance value of government healthcare programs have all ceteris paribus operated to raise neutral real rates. Using estimates drawn from the literature, as well as two general equilibrium models emphasizing respectively life-cycle heterogeneity and individual uncertainty, we suggest that the “private sector neutral real rate” may have declined by as much as 700 basis points since the 1970s

    Evaluating Medical Student Communication/Professionalism Skills from a Patient’s Perspective

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    Objective: Evaluate medical students’ communication and professionalism skills from the perspective of the ambulatory patient and later compare these skills in their first year of residency. Methods: Students in third year neurology clerkship clinics see patients alone followed by a revisit with an attending neurologist. The patient is then asked to complete a voluntary, anonymous, Likert scale questionnaire rating the student on friendliness, listening to the patient, respecting the patient, using understandable language, and grooming. For students who had completed 1 year of residency these professionalism ratings were compared with those from their residency director. Results: Seven hundred forty-two questionnaires for 165 clerkship students from 2007 to 2009 were analyzed. Eighty-three percent of forms were returned with an average of 5 per student. In 64% of questionnaires, patients rated students very good in all five categories; in 35% patients selected either very good or good ratings; and <1% rated any student fair. No students were rated poor or very poor. Sixty-two percent of patients wrote complimentary comments about the students. From the Class of 2008, 52% of students received “better than their peers” professionalism ratings from their PGY1 residency directors and only one student was rated “below their peers.” Conclusion: This questionnaire allowed patient perceptions of their students’ communication/professionalism skills to be evaluated in a systematic manner. Residency director ratings of professionalism of the same students at the end of their first year of residency confirms continued professional behavior

    Prospectus, April 20, 1970

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    ENVIRONMENT TEACH-IN BONEYARD CLEAN UP; Salaries To Come Next Year, Tuition; Guidelines Proposed For Disciplinary Action; Agnew And You; Letters To The Editor; Present Grading System Should Stay---; Refuse To Fight War Undeclared; Veterans Receive Boost; At A Moment\u27s Notice...: Our Parkland Secretaries; PC Nurses Active In State Organization; IFUC Instrumental In GI Bill Raise; Sterile Cuckoo Sad Little Story; Bull Page: Art Contest Held, Calendar, Library Orientation Program Produced, Cole, Reynolds Win Road Rally, News...News, Horrors; Abbey: track Men \u27Excell\u27; Cagers Finish Season 11-13; Intramural Schedulehttps://spark.parkland.edu/prospectus_1970/1029/thumbnail.jp

    Breakthrough Energy Savings with Waterjet Technology

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    Experiments performed at the University of Missouri-Rolla's Waterjet Laboratory have demonstrated clearly the ability of waterjets to disaggregate, in a single step, four different mineral ores, including ores containing iron, lead and copper products. The study focused mainly on galena-bearing dolomite, a lead ore, and compared the new technology with that of traditional mining and milling to liberate the valuable constituent for the more voluminous host rock. The technical term for the disintegration of the ore to achieve this liberation is comminution. The potential for energy savings if this process can be improved, is immense. Further, if this separation can be made at the mining face, then the potential energy savings include avoidance of transportation (haulage and hoisting) costs to move, process and store this waste at the surface. The waste can, instead, be disposed into the available cavities within the mine. The savings also include the elimination of the comminution, crushing and grinding, stages in the processing plant. Future prototype developments are intended to determine if high-pressure waterjet mining and processing can be optimized to become cheaper than traditional fragmentation by drilling and blasting and to optimize the separation process. The basic new mining process was illustrated in tests on two local rock types, a low-strength sandstone with hematite inclusions, and a medium to high-strength dolomite commonly used for construction materials. Illustrative testing of liberation of minerals, utilized a lead-bearing dolomite, and included a parametric study of the optimal conditions needed to create a size distribution considered best for separation. The target goal was to have 50 percent of the mined material finer than 100 mesh (149 microns). Of the 21 tests that were run, five clearly achieved the target. The samples were obtained as run-of-mine lumps of ore, which exhibited a great deal of heterogeneity within the samples. This, in turn, reduced the ability to apply detailed statistical tests to the product outcomes. Nonetheless, a regression analysis showed that operating pressures between 105 (10,000psi) and 140 (15,000psi) MegaPascals (MPa) at traverse speeds no greater than 10 cm/min (4 in/min), best generated the target result. Variation in other parameters, rotation speed, nozzle diameter, and nozzle separation angle, during the preliminary tests did not substantially change the product, and so were kept fixed during the ore mining tests. The experimental protocols were developed to include proper treatment of the lead-bearing materials, which may be considered hazardous. In anticipation of the creation of a mineral processing design for separation of the concentrates from the tailings (waste), assays were made of the metal content of each screen size for each of the 21 runs; with three screens and a pan for undersize, to give a total of 84 assays. This information will enable Dr. McNulty, project consultant, to create a flow sheet for the prototype mining machine. As a preliminary component to such a system, the experimental layout included a product-recovery system that delivered all of the fragmented product to the nest of screens which allowed study of the liberation at the different size levels. Where incomplete liberation is found, a secondary process was demonstrated for using pressurized cavitation to further comminute the material. This concept was successfully demonstrated, with a small cavitation chamber illustrating the much smaller space that such a tool requires, relative to conventional ball and rod mills. Additional testing is ongoing, external to this program, to find whether an one-step process using higher jet pressures and longer dwell times to achieve all the required comminution in mining, is more efficient than a two-step process in which normal jet pressures and feed rates do the initial mining, but full particle liberation is achieved only through secondary processing of the product in a cavitation chamber. Subsequent testing is also planned, to determine preferred methods for separating ore minerals from the waste. Tests with this system have included both the galena samples, and copper ores from Poland. The development of this tool lies within an expanding market for the use of high-pressure waterjet equipment across a broad spectrum of applications. As the industry develops new tools, it is anticipated that the research team will investigate the development of a prototype machine based on these tools, since this will simplify and speed up equipment development. It is hoped that once this is developed that can be taken into an active mine. Such a machine should be able to produce large enough samples to allow assessment of optimal operating conditions

    Prognostic and Predictive Biomarkers in Patients With Coronavirus Disease 2019 Treated With Tocilizumab in a Randomized Controlled Trial

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    OBJECTIVES: To explore candidate prognostic and predictive biomarkers identified in retrospective observational studies (interleukin-6, C-reactive protein, lactate dehydrogenase, ferritin, lymphocytes, monocytes, neutrophils, d-dimer, and platelets) in patients with coronavirus disease 2019 pneumonia after treatment with tocilizumab, an anti-interleukin-6 receptor antibody, using data from the COVACTA trial in patients hospitalized with severe coronavirus disease 2019 pneumonia. DESIGN: Exploratory analysis from a multicenter, randomized, double-blind, placebo-controlled, phase 3 trial. SETTING: Hospitals in North America and Europe. PATIENTS: Adults hospitalized with severe coronavirus disease 2019 pneumonia receiving standard care. INTERVENTION: Randomly assigned 2:1 to IV tocilizumab 8 mg/kg or placebo. MEASUREMENTS AND MAIN RESULTS: Candidate biomarkers were measured in 295 patients in the tocilizumab arm and 142 patients in the placebo arm. Efficacy outcomes assessed were clinical status on a seven-category ordinal scale (1, discharge; 7, death), mortality, time to hospital discharge, and mechanical ventilation (if not receiving it at randomization) through day 28. Prognostic and predictive biomarkers were evaluated continuously with proportional odds, binomial or Fine-Gray models, and additional sensitivity analyses. Modeling in the placebo arm showed all candidate biomarkers except lactate dehydrogenase and d-dimer were strongly prognostic for day 28 clinical outcomes of mortality, mechanical ventilation, clinical status, and time to hospital discharge. Modeling in the tocilizumab arm showed a predictive value of ferritin for day 28 clinical outcomes of mortality (predictive interaction, p = 0.03), mechanical ventilation (predictive interaction, p = 0.01), and clinical status (predictive interaction, p = 0.02) compared with placebo. CONCLUSIONS: Multiple biomarkers prognostic for clinical outcomes were confirmed in COVACTA. Ferritin was identified as a predictive biomarker for the effects of tocilizumab in the COVACTA patient population; high ferritin levels were associated with better clinical outcomes for tocilizumab compared with placebo at day 28
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