A Behavioral Analysis of EPA's MOBILE Emission Factor Model

This paper examines the behavioral and stochastic aspects of modeling emission reductions from vehicle Inspection and Maintenance (I/M) programs. Forecasts of the potential emission reductions from such programs have been modeled by the use of the Environmental Protection Agency's MOBILE Model, EPA's computer model for estimating emission factors for mobile sources. We examine the structure of this Model and review the way behavior of drivers, mechanics and state regulatory authorities is incorporated in the current generation of the Model. We focus particularly on assumptions about vehicle repair under I/M, compliance with I/M requirements, and the impact of test measurement error on predicted I/M effectiveness. We also include some preliminary comparisons of the Model's outcomes to results of the I/M program in place in Arizona. Finally, we perform some sensitivity analyses to determine the most influential underlying parameters of the Model. We find that many of the assumptions of the I/M component of the Model are based on relatively small data sets on vehicle done in a laboratory setting, and that the output of the Model makes it difficult to compare the results against real world data from on-going state programs. In addition, the Model assumes that vehicles will either be repaired or receive a waiver. In the Arizona program there appears to be a third category of vehicles � those which fail the test and do not receive passes. This share may be as high as a third of all failing vehicles. Vehicles which do not eventually pass the test would be treated in the Model as non-compliant. However, in current programs, states do not seem to be measuring and entering the compliance rate correctly. The paper also examines the evidence about whether emissions deteriorate over the life of vehicle in a grams per mile basis (as assumed by the Model) or a grams per gallon basis. It finds support for the argument that emissions deteriorate on a grams per gallon basis. We find through sensitivity analysis that the repair effectiveness assumed by the Model to occur in an IM240 test are much greater than for the idle test, and that identification rates and repair effectiveness vary a great deal according to the cutpoint. These results are based on small numbers of vehicle tests in a laboratory setting and could be compared to real world evidence. Examining costs and cost-effectiveness of variations in I/M programs is important for determining improvements in I/M programs. States may not have incentives to develop cost-effective programs based on current Model that forecast emission reduction "credits" that are overly optimistic.

Cost-Effective NOx Control in the Eastern United States

Reducing nitrogen oxide (NOx) emissions in the eastern United States has become the focus of efforts to meet ozone air quality goals and will be useful for reducing particulate matter (PM) concentrations in the future. This paper addresses many aspects of the debate over the appropriate approach for obtaining reductions in NOx emissions from point sources beyond those called for in the Clean Air Act Amendments of 1990. Data on NOx control technologies and their associated costs, spatial models linking NOx emissions and air quality, and benefit estimates of the health effects of changes in ozone and PM concentrations are combined to allow an analysis of alternative policies in thirteen states in the eastern United States. The first part of the study examines the cost and other consequences of a command-and-control approach embodied in the Environmental Protection Agency’s (EPA) NOx SIP call, which envisions large reductions in NOx from electric utilities and other point sources. These results are compared to the alternative policy of ton-for-ton NOx emissions trading, similar to that proposed by the EPA for utilities. We find that emission reduction targets can be met at roughly 50% cost savings under a trading program when there are no transaction costs. The paper examines a number of alternative economic incentive policies that have the potential to improve upon the utility NOx trading plan proposed by EPA, including incorporation of other point sources in the trading program, incorporation of ancillary PM benefits to ozone reductions in the trading program, and trading on the basis of ozone exposures that incorporates the spatial impact of emissions on ozone levels. For the latter analysis, we examine spatially differentiated permit systems for reducing ozone exposures under different and uncertain meteorological conditions, including an empirical analysis of the trade-off between the reliability (or degree of certainty) of meeting ozone exposure reduction targets and the cost of NOx control. Finally, several policies that combine costs and health benefits from both ozone and PM reductions are compared to command-and-control and single-pollutant trading policies. The first of these is a full multipollutant trading system that achieves a health benefit goal, with the interpollutant trading ratios governed by the ratio of unit health benefits of ozone and PM. Then, a model that maximizes aggregate benefits from both ozone and PM exposure reductions net of the costs of NOx controls is estimated. EPA’s program appears to be reasonably cost-effective compared to all of the other more complex trading programs we examined. It may even be considered an optimal policy that maximizes net aggregate benefits if the high estimate of benefits is used in which mortality risk is linked to ozone exposure. Without this controversial assumption, however, we find that EPA’s NOx reduction target is far too large.

Mbesese Build 2023

In collaboration with the Mbesese Initiative for Sustainable Developments, the senior project group from California Polytechnic State University of San Luis Obispo, researched, designed, and created construction documents for the Same Polytechnic College project in the town of Same, Tanzania. This project aims to combat poverty in the Kilimanjaro Region of Tanzania by providing education and infrastructure development. In 2023, the senior project group focused on completing a communal and educational space and addressing clean water scarcity through a rainwater collection system on the site of the future college

The Chesapeake Bay and the Control of NOx Emissions: A Policy Analysis

Nitrogen oxide emissions not only affect air quality but have recently been found to be an important source of nitrate pollution in the Chesapeake Bay. This analysis examines the costs, emissions, source-specific and location-specific allocations of NOX emissions reductions and the ancillary ozone related health benefits under a range of policy scenarios. The paper includes analysis of three separate policies. The first is a detailed analysis of the effect on nitrate loadings to the Bay of command and control policies specified in the Clean Air Act and as part of the OTAG process. The second is a comparison of alternative scenarios for reducing NOX emissions that meet nitrate loading goals, with or without concern for reducing ozone concentrations and the health effects they cause. The third is a comparison of alternative approaches to allocate NOX emissions to meet NOX reduction and ozone exposure goals while capturing the ancillary effect on nitrate loadings. This last analysis focuses on the stake the Bay jurisdictions have in the outcome of negotiations over NOX trading programs being developed by EPA for reducing ozone in the Eastern U.S. With the primary focus on the Chesapeake Bay jurisdiction, all three analyses integrate the ancillary ozone benefits of policies to reduce nitrate pollution, including examination of how these ancillary benefits change under alternative meteorological episodes, and explore lower cost alternatives to current regulatory programs in both qualitative and quantitative terms. We find that the Chesapeake Bay benefits from efforts to reduce NOX emissions to meet the ambient air quality standard for ozone. Airborne NOX emission reductions slated to occur under the Clean Air Act in the Bay airshed will reduce nitrate loadings to the Bay by about 27 percent of the baseline airborne levels. The additional controls of NOX contemplated in what we term the OTAG scenario is estimated to result in an additional 20 percent reduction from this baseline. However, the paper's analysis of possible least cost options shows that the costs of obtaining such reductions can be significantly reduced by rearranging the allocation of emissions reductions to take advantage of source-type and locational considerations. In addition, we find that adding consideration of ancillary ozone-related health benefits to the picture does not alter any qualitative conclusions. Quantitatively, unless a link between ozone and mortality risk is assumed, the benefits are too small to affect the cost-saving allocations of NOX reductions. If the case for such a link can be made, the results change dramatically, with large overall increases in NOX reductions and a relative shift in controls to non-Bay states and utility sources. These specific effects are sensitive to the source-receptor coefficients linking NOX to ozone, however. Our analyses also suggest that the Bay jurisdictions have a stake in the outcome of the NOX trading debate -- that some trading designs can lead to better outcomes for these jurisdictions than others. Nevertheless, a common feature of cost-savings policies is that they both rearrange emissions reductions and, in the aggregate, reduce emissions less than a command and control system. Thus, some trading regimes result in significantly smaller loadings reductions (up to 25 percent smaller) than the command and control approach.

Development as Leadership-led Change

Development involves change, but many development initiatives produce unimpressive results. The authors ask why and consider how to close the gap between the intended change and what we actually see in the evidence. This paper presents the findings of a study, initiated by the multi-donor Global Leadership Initiative and led by the World Bank Institute (WBI), to examine leadership in the change processes of fourteen capacity development interventions in eight developing countries, through 140 in-depth structured interviews. It explores what it takes to make change happen and in particular, the role leadership plays in effecting change. The authors propose that leadership contributes to change when it builds “change space” by fostering acceptance for change, granting authority for change, introducing or freeing the abilities necessary to achieve change. This “change space” is required to ensure contextual readiness for change and foster progress through the difficult stages of the change process. An analytical framework is introduced to illustrate the dimensions of this “change space” and its limits in organizational and social change. The authors argue that a lack of “change space” in many development contexts may be overlooked, contributing to failure. The paper concludes that leadership manifests in different ways in different contexts, depending on the contextual readiness and factors that shape change and leadership opportunities; but the key characteristics of plurality, functionality, problem orientation and “change space” creation are likely to be common to all successful leadership-led change events

Myosin-1a powers the sliding of apical membrane along microvillar actin bundles

Microvilli are actin-rich membrane protrusions common to a variety of epithelial cell types. Within microvilli of the enterocyte brush border (BB), myosin-1a (Myo1a) forms an ordered ensemble of bridges that link the plasma membrane to the underlying polarized actin bundle. Despite decades of investigation, the function of this unique actomyosin array has remained unclear. Here, we show that addition of ATP to isolated BBs induces a plus end–directed translation of apical membrane along microvillar actin bundles. Upon reaching microvillar tips, membrane is “shed” into solution in the form of small vesicles. Because this movement demonstrates the polarity, velocity, and nucleotide dependence expected for a Myo1a-driven process, and BBs lacking Myo1a fail to undergo membrane translation, we conclude that Myo1a powers this novel form of motility. Thus, in addition to providing a means for amplifying apical surface area, we propose that microvilli function as actomyosin contractile arrays that power the release of BB membrane vesicles into the intestinal lumen

Two Dimensional Sign Language Agent

No abstract available

Inflammatory Markers Associated With Subclinical Coronary Artery Disease: The Multicenter AIDS Cohort Study.

BackgroundDespite evidence for higher risk of coronary artery disease among HIV+ individuals, the underlying mechanisms are not well understood. We investigated associations of inflammatory markers with subclinical coronary artery disease in 923 participants of the Multicenter AIDS Cohort Study (575 HIV+ and 348 HIV- men) who underwent noncontrast computed tomography scans for coronary artery calcification, the majority (n=692) also undergoing coronary computed tomography angiography.Methods and resultsOutcomes included presence and extent of coronary artery calcification, plus computed tomography angiography analysis of presence, composition, and extent of coronary plaques and severity of coronary stenosis. HIV+ men had significantly higher levels of interleukin-6 (IL-6), intercellular adhesion molecule-1, C-reactive protein, and soluble-tumor necrosis factor-α receptor (sTNFαR) I and II (all P<0.01) and a higher prevalence of noncalcified plaque (63% versus 54%, P=0.02) on computed tomography angiography. Among HIV+ men, for every SD increase in log-interleukin-6 and log intercellular adhesion molecule-1, there was a 30% and 60% increase, respectively, in the prevalence of coronary stenosis ≥50% (all P<0.05). Similarly, sTNFαR I and II in HIV+ participants were associated with an increase in prevalence of coronary stenosis ≥70% (P<0.05). Higher levels of interleukin-6, sTNFαR I, and sTNFαR II were also associated with greater coronary artery calcification score in HIV+ men (P<0.01).ConclusionsHigher inflammatory marker levels are associated with greater prevalence of coronary stenosis in HIV+ men. Our findings underscore the need for further study to elucidate the relationships of inflammatory pathways with coronary artery disease in HIV+ individuals