Unintended Consequences from Nested State & Federal Regulations: The Case of the Pavley Greenhouse-Gas-per-Mile Limits

Fourteen U.S. states recently pledged to adopt limits on greenhouse gases (GHGs) per mile of light-duty automobiles. Previous analyses predicted that these limits will yield significant reductions in GHGs. However, these studies did not consider critical factors that imply different results. This paper develops a multi-period numerical simulation model that accounts for these factors in assessing the impact of the proposed GHG-per-mile standards on U.S. gasoline consumption and GHG emissions. We find that while the state-level initiative would reduce significantly the emissions associated with new cars in the adopting states, it would give rise to very significant offsetting increases (“leakage”) elsewhere, in both new and used car markets. Because of interactions with the federal CAFE standard, technology spillovers mitigate leakage only slightly. In the most plausible scenarios considered, the leakage is around 70 percent. Correspondingly, the cost per gallon saved under the GHG-per-mile limits is about 72 percent higher than for an equivalent increase in the federal CAFE standard.greenhouse gases, environmental regulations, renewable energy, cars

Disruption of an RNA helicase/RNAse III gene in Arabidopsis causes unregulated cell division in floral meristems

Arabidopsis thaliana floral meristems are determinate structures that produce a defined number of organs, after which cell division ceases. A new recessive mutant, carpel factory (caf), converts the floral meristems to an indeterminate state. They produce extra whorls of stamens, and an indefinite number of carpels. Thus, CAF appears to suppress cell division in floral meristems. The function of CAF is partially redundant with the function of the CLAVATA (CLV) and SUPERMAN (SUP) genes, as caf clv and caf sup double mutants show dramatically enhanced floral meristem over-proliferation. caf mutant plants also show other defects, including absence of axillary inflorescence meristems, and abnormally shaped leaves and floral organs. The CAF gene was cloned and found to encode a putative protein of 1909 amino acids containing an N-terminal DExH/DEAD-box type RNA helicase domain attached to a C-terminal RNaseIII-like domain. A very similar protein of unknown function is encoded by a fungal and an animal genome. Helicase proteins are involved in a number of processes, including specific mRNA localization and mRNA splicing. RNase III proteins are involved in the processing of rRNA and some mRNA molecules. Thus CAF may act through some type of RNA processing event(s). CAF gives rise to two major transcripts of 2.5 and 6.2 kb. In situ hybridization experiments show that CAF RNA is expressed throughout all shoot tissues

Comparative clinical evaluation of rub vs. no rub lens care regimens for a silicone hydrogel soft contact lens

Purpose. Although no-rub cleaning regimens have proven effective with traditional HEMA based lenses, there has been little reported on the impact of deleting the rubbing step for silicone hydrogel lenses. This study investigated the impact of a rub vs. no-rub cleaning regimen on the comfort of a silicone hydrogel contact lens. Methods. Sixteen subjects wore 0 20ptix silicone hydrogel contact lenses (CIBA Vision, Duluth, GA) on a daily wear schedule for two consecutive two week periods. The study was a subject-blind cross-over study in which the subjects were told they would be comparing the comfort of two different silicone hydrogel lenses. They were instructed to rub and rinse the lenses for 2 weeks and rinse without rubbing the lenses for the other 2 weeks using OPTI-FREE! RepleniSH™ (Alcon, Fort Worth, Texas) cleaning solution. Subjective comfort and symptoms were assessed after 2 weeks with each cleaning regimen. Results: Mean comfortable wearing time for the rubbed lenses (R) was 10 hours (95% CI 7.9, 12.0) compared to the non-rubbed (NR) at 8.35 hours (95% Cl6.1, 10.6). P = 0.1064. Comfort as recorded on a visual analogue scale had a mean of75.1 for the Rand 66.4 for the NR. P = 0.3708. The R group scored higher for overall comfort, end of day comfort and dryness. Forced choice results indicated that subjects preferred the R regimen over the NR. P = 0.0847. There were no differences in slit lamp examination findings. Conclusions: A cleaning regimen consisting of a 10 second rub showed a trend towards improved comfort and wear time in a pilot study of silicone hydrogel lens wearers. Practitioners may wish to consider this when prescribing lens care for these patients, however, further research with a larger sample size would be warranted to confirm the results of this study

Distributional and Efficiency Impacts of Gasoline Taxes: An Econometrically Based Multi-market Study.

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Distributional and efficiency impacts of gasoline taxes.

This article examines the gasoline tax option being proposed in the U.S. in 2005, employing an econometrically based multi-market simulation model to explore the policy's efficiency and distributional implications. Because of its potential to improve the environment and enhance national security, reducing automobile-related gasoline consumption has become a major U.S. public policy issue. Policy impacts both in the aggregate and across households distinguished by income, car-ownership, and other characteristics were examined. Simulation results show that whether a gas-tax increase is regressive in its impact depends on the manner in which the tax revenues are recycled to the economy. The results also reveal significant heterogeneity in welfare impacts within household income groups, thus highlighting the importance of accounting for household heterogeneity in tastes and car-ownership in evaluating distributional impacts.

Unintended Consequences From Nested State and Federal Regulations: The Case of the Pavley Greenhouse-gas-per-mile Limits

This paper reveals significant unintended consequences from recent 14-state efforts to reduce greenhouse gas emissions through limits on greenhouse gases per mile from new cars. We show that while such efforts significantly reduce emissions from new cars sold in the adopting states, they cause substantial emissions increases from new cars sold in other (non-adopting) states and from used cars. The costs per avoided ton of emissions are approximately twice as high once such offsets are recognized. Such offsets (or “leakage”) reflect interactions between the state-level initiatives and the federal fuel-economy standard: the state-level efforts effectively loosen the national standard, giving automakers scope to profitably increase sales of high-emissions automobiles in non-adopting states. Although the state-level efforts spur invention of fuel- and emissions-saving technologies, interactions with the federal standard limit the nationwide emissions reductions from such advances. Our multi-period simulation model estimates that a recent state-federal agreement avoids what would have been 74% leakage in the first phase of the state-level effort, and that potential for 65% leakage remains for the second phase. This research confronts a general issue of policy significance—namely, problems from “nested” state and federal environmental regulations. Similar leakage difficulties would arise under several newly proposed state-level initiatives

Enset‐based agricultural systems in Ethiopia: A systematic review of production trends, agronomy, processing and the wider food security applications of a neglected banana relative

Enset (Ensete ventricosum (Welw.) Cheesman) is the major starch staple of the Ethiopian Highlands, where its unique attributes enhance the food security of approximately 20 million people and have earned it the title “The Tree Against Hunger”. Yet enset‐based agriculture is virtually unknown outside of its narrow zone of cultivation, despite growing wild across much of East and Southern Africa. Here, we review historical production data to show that the area of land under enset production in Ethiopia has reportedly increased 46% in two decades, whilst yield increased 12‐fold over the same period, making enset the second most produced crop species in Ethiopia—though we critically evaluate potential issues with these data. Furthermore, we address a major challenge in the development and wider cultivation of enset, by reviewing and synthesizing the complex and fragmented agronomic and ethnobotanic knowledge associated with this species; including farming systems, processing methods, products, medicinal uses and cultural importance. Finally, we provide a framework to improve the quality, consistency and comparability of data collected across culturally diverse enset‐based agricultural systems to enhanced sustainable use of this neglected starch staple. In conclusion, we discuss the challenges and opportunities for enset cultivation beyond its restricted distribution, and the regional food security potential it could afford smallholders elsewhere in Southern and East Africa