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Ridesourcing fleets present an opportunity for rapid uptake of battery electric vehicles (BEVs) but adoption has largely been limited to small pilot projects. Lack of charging infrastructure presents a major barrier to scaling up, but little public information exists on the infrastructure needed to support ridesourcing electrification. With data on ridesourcing trips for New York City and San Francisco, and using agent-based simulations of BEV fleets, we show that given a sparse network of three to four 50 kW chargers per square mile, BEVs can provide the same level of service as internal combustion engine vehicles (ICEVs) at lower cost. This suggests that the cost of charging infrastructure is not a significant barrier to ridesourcing electrification. With coordinated use of charging infrastructure across vehicles, we also find that fleet performance becomes robust to variation in battery range and placement of chargers. Our analysis suggests that mandates on ridesourcing such as the California Clean Miles Standard could achieve electrification without significantly increasing the cost of ridesourcing services.

As the transportation sector undergoes three major transformations—electrification, shared/on-demand mobility, and automation—there are new challenges to analyzing the impacts of these trends on both the transportation system and the power sector. Most models that analyze the requirements of fleets of shared autonomous electric vehicles (SAEVs) operate at the scale of an urban region, or smaller. A quadratically constrained, quadratic programming problem is formulated, designed to model the requirements of SAEVs at a national scale. The size of the SAEV fleet, the necessary charging infrastructure, the fleet charging schedule, and the dispatch required to serve demand for trips in a region are treated as decision variables. By minimizing both the amortized cost of the fleet and chargers as well as the operational costs of charging, it is possible to explore the coupled interactions between system design and operation. To apply the model at a national scale, key complications about fleet operations are simplified; but a detailed agent-based regional simulation model to parameterize those simplifications is leveraged. Preliminary results are presented, finding that all mobility in the United States (U.S.) currently served by 276 million personally owned vehicles could be served by 12.5 million SAEVs at a cost of $ 0.27/vehicle-mile or $ 0.18/passenger-mile. The energy requirements for this fleet would be 1142 GWh/day (8.5% of 2017 U.S. electricity demand) and the peak charging load 76.7 GW (11% of U.S. power peak). Several model sensitivities are explored, and it is found that sharing is a key factor in the analysis.

Transportation is the fastest-growing source of greenhouse gas (GHG) emissions and energy consumption globally. While the convergence of shared mobility, vehicle automation, and electrification has the potential to drastically reduce transportation impacts, it requires careful integration with rapidly evolving electricity systems. Here, we examine these interactions using a U.S.-wide simulation framework encompassing private electric vehicles (EVs), shared automated EVs (SAEVs), charging infrastructure, controlled EV charging, and a grid economic dispatch model to simulate personal mobility exclusively using EVs. We find that private EVs with uncontrolled charging would reduce GHG emissions by 46% compared to gasoline vehicles. Private EVs with fleetwide controlled charging would achieve a 49% reduction in emissions from baseline and reduce peak charging demand by 53% from the uncontrolled scenario. We also find that an SAEV fleet 9% the size of today's active vehicle fleet can satisfy trip demand with only 2.6 million chargers (0.2 per EV). Such an SAEV fleet would achieve a 70% reduction in GHG emissions at 41% of the lifecycle cost as a private EV fleet with controlled charging. The emissions and cost advantage of SAEVs is primarily due to reduced vehicle manufacturing compared with private EVs.

Shared automated electric vehicles (SAEVs) hold great promise for improving transportation access in urban centers while drastically reducing transportation-related energy consumption and air pollution. Using taxi-trip data from New York City, we develop an agent-based model to predict the battery range and charging infrastructure requirements of a fleet of SAEVs operating on Manhattan Island. We also develop a model to estimate the cost and environmental impact of providing service and perform extensive sensitivity analysis to test the robustness of our predictions. We estimate that costs will be lowest with a battery range of 50-90 mi, with either 66 chargers per square mile, rated at 11 kW or 44 chargers per square mile, rated at 22 kW. We estimate that the cost of service provided by such an SAEV fleet will be $0.29-$0.61 per revenue mile, an order of magnitude lower than the cost of service of present-day Manhattan taxis and $0.05-$0.08/mi lower than that of an automated fleet composed of any currently available hybrid or internal combustion engine vehicle (ICEV). We estimate that such an SAEV fleet drawing power from the current NYC power grid would reduce GHG emissions by 73% and energy consumption by 58% compared to an automated fleet of ICEVs.

A growing number of labral changes are described in the literature. The purpose of this study was to evaluate the glenoid and labrum of normal shoulders at different ages and characterize any apparent age-dependent changes. We analyzed 32 normal cadaveric shoulders with a mean age of 57 years (range, 18-89 years). There were 22 male and 10 female cadavers, with 14 right and 18 left specimens. The shoulders were studied macroscopically, histologically, and radiologically. The radiologic evaluation consisted of an analysis of the subchondral mineralization of the glenoid with the use of computed tomographic osteoabsorptiometry. Macroscopically, there were no statistically significant differences among the age groups. Histopathologically, the labrum showed a significant qualitative and quantitative increase (P <.01) in lesions across all regions with increasing age. In younger individuals, lesions at the 12-o'clock position were the most prevalent, with the incidence increasing with age. The anterosuperior position was the region with the next highest prevalence. This was also the area of the highest stress distribution on the glenoid. Our studies demonstrated clear histopathologic changes of the glenoid labrum that are significantly age-related at specific sites. The earliest changes are seen close to the area of highest stress distribution of the glenoid, which could explain the progressive labral changes with increasing age. Arthroscopically detected changes of the glenoid labrum should be evaluated in the context of age-related changes in normal shoulders.

Charles Neer designed his original prosthesis in 1951. It was made of cast cobalt chrome alloy and was only press-fit. There was not any significant loosening in his original series, but patients complained of easy fatigability. This finding was attributed to glenoid issues and a cemented glenoid replacement was introduced in 1973. High rates of lucencies were reported and raised issues regarding fixation. Cementless glenoid components have been found to have fewer lucencies but require metal backing. Higher failure rates have been reported for the cementless design versus the cemented glenoids. With humeral fixation, symptomatic loosening is not a problem with cement or coated press-fit fixation. Long-term outcome studies with cemented and uncemented stems have shown the incidence of humeral loosening to be low. Fixation of humeral components should be based on bone quality, patient age, prosthetic design, and surgeon preference., (Copyright 2002, Elsevier Science (USA).)

Purpose: The purpose of this study was to examine the effectiveness of an arthroscopically placed intra-articular pain catheter for controlling postoperative pain and also review the results following arthroscopic release of refractor adhesive capsulitis., Type of Study: Retrospective clinical trial., Methods: Twenty-three consecutive cases (20 patients) of arthroscopic adhesive capsulitis release in which an intra-articular pain catheter was used were reviewed. Follow-up ranged from 12 to 37 months (average, 22.4 months). An intra-articular catheter was placed under direct arthroscopic visualization from a superior approach into the glenohumeral joint. Postoperatively, patients were injected with 10 mL of 0.5% bupivacaine every 6 hours as needed. Preoperatively, all patients had filled out a questionnaire based on the American Shoulder and Elbow Surgeons (ASES) outcome guidelines and examined for range of motion. Postoperatively, patients were asked for their precatheter and postcatheter injection pain level based on the visual analog scale (1 to 10 points, 1 = no pain). Patients were then examined for range of motion and retested with the outcome questionnaire. An ASES Shoulder Score Index was calculated for each patient before and after the procedure., Results: The average forward elevation preoperatively was 102 degrees and external rotation at the side was 4.5 degrees. At most recent follow-up, average forward elevation was 169 degrees with external rotation at the side 47 degrees. The Shoulder Score Index increased from an average of 37.1 out of 100 to 90.9 (P <.001). Before being injected with anesthetic through the catheter, patients had an average visual analog scale score of 8.1. Postinjection average pain level was 1.2 (P <.001) and all patients indicated that the pain catheter significantly reduced postoperative pain. Nineteen of 20 patients were satisfied with the procedure., Conclusions: Placement of an intra-articular pain catheter for delivery of bupivacaine was highly effective in controlling postoperative pain. In all cases, postoperative pain was essentially eliminated and this substantially assisted with range of motion exercises. Near complete restoration of range of motion without pain was achieved in 95% of the patients.

This study was undertaken to identify differences in the sonographic appearance of acute and chronic full-thickness rotator cuff tears. The ultrasonograms of 24 patients with an acute rotator cuff tear and 20 with a chronic tear were reviewed for tear size (width), location, and the presence and distribution of fluid. Among these 24 patients, 75% with a midsubstance tear location had an acute tear; 64% of patients with joint or bursal fluid had an acute tear; 80% of patients with a nonvisualized rotator cuff due to a massive tear had a chronic tear; and 73% of patients with no sonographic evidence of bursal or joint fluid had a chronic tear. In conclusion, a midsubstance location and the presence of joint or bursal fluid were more commonly associated with an acute tear. A nonvisualized cuff and the absence of joint and bursal fluid were more commonly observed with a chronic tear.

Mitochondrial fatty acid oxidation provides most of the energy required for myocardial function after birth. Long chain acyl-CoA dehydrogenase (LCAD) catalyzes the first step in the beta-oxidation spiral. Our objective was to define regulatory elements of the human LCAD gene required for high levels of expression in mature heart and to locate elements suppressing gene expression in the fetus. We characterized the human LCAD gene structure and used in vitro transfection into cardiomyocytes and hepatoma cells of LCAD genomic fragments fused to a reporter gene to examine the effects of putative regulatory elements on transcription. Binding of transcription factors to nuclear hormone receptor consensus DNA binding domains was studied by gel shift experiments. The 200 bp of the human LCAD gene immediately upstream of the transcription initiation site are sufficient to act as a minimal promoter for the gene and provide some tissue-specific positive regulatory elements. The region from -1800 bp to -250 bp contains elements which markedly suppress transcription, including nuclear hormone receptor response elements. The dominant interaction is with the repressor factor, chicken ovalbumin upstream promoter transcription factor. We conclude that the developmental and tissue-specific regulation of the human LCAD gene is mediated, in part, by these nuclear hormone receptor transcription factors.

17-beta-Estradiol dehydrogenase is required for the enzymatic interconversion of estradiol and its weaker related sex steroid, estrone. We isolated and sequenced a complementary deoxyribonucleic acid clone for 17 beta-estradiol dehydrogenase from the BeWo choriocarcinoma cell line. Comparison of the BeWo complementary deoxyribonucleic acid sequence to a previously derived placental complementary deoxyribonucleic acid sequence yields greater than 98% homology. We also isolated the gene for 17 beta-estradiol dehydrogenase from the Jar human choriocarcinoma cell line and elucidated its primary nucleic acid structure. Significant differences in the Jar-deduced complementary deoxyribonucleic acid sequence clearly differentiate it from both the human placental and BeWo forms of 17 beta-estradiol dehydrogenase, indicating the existence of two genes for 17 beta-estradiol dehydrogenase in the human genome. Evaluation of 17 beta-estradiol dehydrogenase gene expression in BeWo and Jar cells was compared with expression in luteinized granulosa cells. Messenger ribonucleic acid for human placental 17 beta-estradiol dehydrogenase was identified in all three cell types as a 1.3 kilobase band on Northern blot analysis. A second messenger ribonucleic acid species measuring 2.1 kilobase was abundantly present in the granulosa cells. Whether these two species of messenger ribonucleic acid are involved in the regulation of the estradiol dehydrogenase genes is yet to be determined.