Shared stand-up electric scooters are now offered in many cities as an option for short-term rental, and marketed for short-distance travel. Using life cycle assessment, we quantify the total environmental impacts of this mobility option associated with global warming, acidification, eutrophication, and respiratory impacts. We find that environmental burdens associated with charging the e-scooter are small relative to materials and manufacturing burdens of the e-scooters and the impacts associated with transporting the scooters to overnight charging stations. The results of a Monte Carlo analysis show an average value of life cycle global warming impacts of 202 g CO 2 -eq/passenger-mile, driven by materials and manufacturing (50%), followed by daily collection for charging (43% of impact). We illustrate the potential to reduce life cycle global warming impacts through improved scooter collection and charging approaches, including the use of fuel-efficient vehicles for collection (yielding 177 g CO 2 -eq/passenger-mile), limiting scooter collection to those with a low battery state of charge (164 g CO 2 -eq/passenger-mile), and reducing the driving distance per scooter for e-scooter collection and distribution (147 g CO 2 -eq/passenger-mile). The results prove to be highly sensitive to e-scooter lifetime; ensuring that the shared e-scooters are used for two years decreases the average life cycle emissions to 141 g CO 2 -eq/passenger-mile. Under our Base Case assumptions, we find that the life cycle greenhouse gas emissions associated with e-scooter use is higher in 65% of our Monte Carlo simulations than the suite of modes of transportation that are displaced. This likelihood drops to 35%-50% under our improved and efficient e-scooter collection processes and only 4% when we assume two-year e-scooter lifetimes. When e-scooter usage replaces average personal automobile travel, we nearly universally realize a net reduction in environmental impacts.

Due to the complexity of power systems, tracking emissions attributable to a specific electrical load is a daunting challenge but essential for many environmental impact studies. Currently, no consensus exists on appropriate methods for quantifying emissions from particular electricity loads. This paper reviews a wide range of the existing methods, detailing their functionality, tractability, and appropriate use. We identified and reviewed 32 methods and models and classified them into two distinct categories: empirical data and relationship models and power system optimization models. To illustrate the impact of method selection, we calculate the CO2 combustion emissions factors associated with electric-vehicle charging using 10 methods at nine charging station locations around the United States. Across the methods, we found an up to 68% difference from the mean CO2 emissions factor for a given charging site among both marginal and average emissions factors and up to a 63% difference from the average across average emissions factors. Our results underscore the importance of method selection and the need for a consensus on approaches appropriate for particular loads and research questions being addressed in order to achieve results that are more consistent across studies and allow for soundly supported policy decisions. The paper addresses this issue by offering a set of recommendations for determining an appropriate model type on the basis of the load characteristics and study objectives.

Specific clinical, program, and system level changes are recommended to help change the culture of obstetric care settings to optimize depression treatment.

Investigations of the effects of valinomycin on mitochondria" 2 led to the discovery of antibiotic-mediated ion transport.3 Subsequent work revealed that this property is shared by valinomycin, the enniatins, the macrolide actins, and the gramicidins, including an extensive array of natural and synthetic analogues.4-6 Passive ion permeability effects have been reported obtained with these agents on other systems including erythroeytes,7 synthetic lipid vesicles,7 and artificial bimolecular lipid leaflets.8' 9 The macrolide actins can even mediate cation transport, as detected by biionic potential development across a bulk phase of CCl4.l1 All these antibiotics, which have in common low molecular weights (ca. 500-1500), a curious alternation of D and L configurations, lipid solubility, and a lack of ionizable groups, will be referred to collectively as the valinomycin class of antibiotics. A second class of transport-mediating antibiotics, including nigericin dianemycin, and others, has been found to reverse transport induced by the valinomycin class."1-'4 All members of the second class possess low molecular weights (450-950), and lipid solubility, and contain an ionizable carboxyl group.'4 This communication will establish that both classes of antibiotics act analogously in many respects, both in mitochondria and in a variety of other lipid barrier systems. Methods and Materials.-Multiparameter measurements of rat liver mitochondria and other systems, during antibiotic-induced ion movements, were carried out with the apparatus described in detail previously.'5 K+ was monitored with the Beckman 39047 electrode, 02 by a Clark-type membrane electrode, pH by the A. H. Thomas 4858 combination electrode, fluorescence by 450-ma light excited by a 366-mn beam, and light-scattering at 650 mis. Mitochondria were prepared and protein was determined as described previously.'6 Samples of nigericin were obtained from H. A. Lardy, R. Harned (Commercial Solvents Corp.), and M. Gorman (Eli Lilly Co.), dianemycin from Lardy and Gorman, oligomycin from F. M. Strong, and p-trifluoromethoxy arboxylcyanide phenylhydrazone (FCCP) from P. Heytler (duPont). Valinomycin was prepared by means of a Streptomyces culture donated by J. C. McDonald according to a modification of his procedure.'7 Results.-The responses of mitochondria to valinomycin addition as shown in

After completing this course, the reader will be able to:1. Evaluate early data regarding the impact of daily vaginal testosterone on estradiol and testosterone levels in breast cancer patients receiving treatment with aromatase inhibitors.2. Explain the potential clinical benefits of vaginal testosterone therapy to treat vaginal atrophy in women with breast cancer receiving long-term aromatase inhibitor therapy.This article is available for continuing medical education credit at CME.TheOncologist.com. CME CME The Oncologist CME Program is located online at http://cme.theoncologist.com/. To take the CME activity related to this article, you must be a registered user. ABSTRACT Breast CancerThe