Evidence of a Shift in the Short-Run Price Elasticity of Gasoline Demand

Understanding the sensitivity of gasoline demand to changes in prices and income has important implications for policies related to climate change, optimal taxation and national security, to name only a few. While the short-run price and income elasticities of gasoline demand in the United States have been studied extensively, the vast majority of these studies focus on consumer behavior in the 1970s and 1980s. There are a number of reasons to believe that current demand elasticities differ from these previous periods, as transportation analysts have hypothesized that behavioral and structural factors over the past several decades have changed the responsiveness of U.S. consumers to changes in gasoline prices. In this paper, we compare the price and income elasticities of gasoline demand in two periods of similarly high prices from 1975 to 1980 and 2001 to 2006. The short-run price elasticities differ considerably: and range from -0.034 to -0.077 during 2001 to 2006, versus -0.21 to -0.34 for 1975 to 1980. The estimated short-run income elasticities range from 0.21 to 0.75 and when estimated with the same models are not significantly different between the two periods.

Seamless Online Distribution of Amundsen Multibeam Data

Since 2003, all underway multibeam and sub-bottom data from the Canadian Coast Guard Ship Amundsen has been posted online within approximately six months of the end of each cruise. A custom interface allowing the user to access 15\u27 latitude by 30\u27 longitude mapsheets was implemented in 2006, allowing the user to download the bathymetric and backscatter data at 10 metre resolution. While this interface matched the underlying data management scheme implemented at the University of New Brunswick, the zoom and pan capability was at a fixed scale with limited contextual data. In the past few years, with the introduction of web-based geographic information systems (GIS) (e.g. Google Maps, Yahoo Maps, Bing Maps), there have been thousands of maps published online. These online GIS programs are a suitable platform to display the seven years of Amundsen coverage within the context of the GIS-served satellite imagery and allow the user to freely browse all data in a familiar interface. The challenge, however, for serving up third party data through these map engines is to efficiently cope with the multiple zoom levels and changing resolutions. Custom tiling software was developed to take all the raw data from the seven years of Amundsen (and others\u27) multibeam coverage and convert it into multiple scale resolution images suitable for interpretation by Google Maps. The images were stored in a pyramid structure utilizing Google\u27s map projection and uniquely named to reflect their georeferencing and resolution. This image pyramid is then accessed by Google Maps according to the user\u27s current zoom level to optimize visualization. This multi-resolution data is served up on demand from the University of New Brunswick for dynamic overlay on Google\u27s satellite data. This web interface allows any interested parties to easily view multibeam and sub-bottom data from the Pacific Ocean through the Canadian Arctic Archipelago and into the Atlantic Ocean. The broad overview helps to understand regional trends and then focus on areas of interest at high resolutions to see particular features. The web interface also provides a link to the 15\u27 by 30\u27 mapsheet model with full source traceability

Natural daylight and the simulation of its effects upon stomata

The spectral composition of natural daylight was examined using horizontal planar receptor surfaces. During the day, incident spectra were remarkably uniform. Particular attention was paid to physiologically important variables. The mean 660:730 nm photon fluence ratio (R:FR) was 1.15, corresponding to a phytochrome photoequilibrium of 0.53, but in late winter R:FR was lower than in late summer (ca. 1.0 and 1.25 respectively). The mean blue:red ratio (0.86) was strongly affected by cloud cover. The light environment of shade habitats was also examined. Under cloudy conditions in an oak woodland, R:FR fell to ca. 0.55 during the leafy phase, but higher values (ca. 0.8) were recorded in late summer as a result of the seasonal trend in incident R:FR. Reflectance and transmittance spectra and pigment content of the leaves and the transmittance of the canopy were measured. Beneath a dense sugar beet canopy, R:FR was well-correlated with canopy transmittance and fell to very low levels (ca. 0.06). However, even this would not sustain a classical "high irradiance response", so it is unlikely to be important under natural conditions. In all three habitats, R:FR was lower and the blue:red ratio higher during twilight than during the day, but the latter was much less affected by the canopies. However, fluence rate was much more reliable as potential source of photoperiodic time signals. The involvement of phytochrome amd other receptors is discussed. Leaf and stomatal morphogenesis in Chenopodium album L. was studied using a high irradiance growth cabinet. Reduced fluence rates of white or blue light produced larger leaves but had no effect on stomatal index (SI) while supplemntary far-red reduced SI but had no effect on leaf area. Thus. both factors affect stomatal density. However no differences in gas exchange characteristics were detected. A flexible computer graphics program for data plotting is also described

Natural daylight and the simulation of its effects upon stomata

The spectral composition of natural daylight was examined using horizontal planar receptor surfaces. During the day, incident spectra were remarkably uniform. Particular attention was paid to physiologically important variables. The mean 660:730 nm photon fluence ratio (R:FR) was 1.15, corresponding to a phytochrome photoequilibrium of 0.53, but in late winter R:FR was lower than in late summer (ca. 1.0 and 1.25 respectively). The mean blue:red ratio (0.86) was strongly affected by cloud cover. The light environment of shade habitats was also examined. Under cloudy conditions in an oak woodland, R:FR fell to ca. 0.55 during the leafy phase, but higher values (ca. 0.8) were recorded in late summer as a result of the seasonal trend in incident R:FR. Reflectance and transmittance spectra and pigment content of the leaves and the transmittance of the canopy were measured. Beneath a dense sugar beet canopy, R:FR was well-correlated with canopy transmittance and fell to very low levels (ca. 0.06). However, even this would not sustain a classical "high irradiance response", so it is unlikely to be important under natural conditions. In all three habitats, R:FR was lower and the blue:red ratio higher during twilight than during the day, but the latter was much less affected by the canopies. However, fluence rate was much more reliable as potential source of photoperiodic time signals. The involvement of phytochrome amd other receptors is discussed. Leaf and stomatal morphogenesis in Chenopodium album L. was studied using a high irradiance growth cabinet. Reduced fluence rates of white or blue light produced larger leaves but had no effect on stomatal index (SI) while supplemntary far-red reduced SI but had no effect on leaf area. Thus. both factors affect stomatal density. However no differences in gas exchange characteristics were detected. A flexible computer graphics program for data plotting is also described

Some Inconvenient Truths About Climate Change Policy: The Distributional Impacts of Transportation Policies

Instead of efficiently pricing greenhouse gases, policy makers have favored measures that implicitly or explicitly subsidize low carbon fuels. We simulate a transportation-sector cap & trade program (CAT) and three policies currently in use: ethanol subsidies, a renewable fuel standard (RFS), and a low carbon fuel standard (LCFS). Our simulations confirm that the alternatives to CAT are quite costly—2.5 to 4 times more expensive. We provide evidence that the persistence of these alternatives in spite of their higher costs lies in the political economy of carbon policy. The alternatives to CAT exhibit a feature that make them amenable to adoption|a right skewed distribution of gains and losses where many counties have small losses, but a smaller share of counties gain considerably—as much as $6,800 per capita, per year. We correlate our estimates of gains from CAT and the RFS with Congressional voting on the Waxman-Markey cap & trade bill, H.R. 2454. Because Waxman-Markey (WM) would weaken the RFS, House members likely viewed the two policies as competitors. Conditional on a district's CAT gains, increases in a district's RFS gains are associated with decreases in the likelihood of voting for WM. Furthermore, we show that campaign contributions are correlated with a district's gains under each policy and that these contributions are correlated with a Member's vote on WM.Institute of Transportation Studies at UC Davi

Strategic Policy Choice in State-Level Regulation: The EPA's Clean Power Plan

The EPA's Clean Power Plan sets goals for CO₂ emissions rate reductions by 2030 that vary substantially across states. States can choose the regulatory mechanism they use and whether or not to join with other states in implementing their goals. We analyze incentives to adopt rate standards versus cap-and-trade with theory and simulation. We show conditions where adoption of inefficient rate standards is a dominant strategy from both consumers' and generators' perspectives. Numerical simulations of the western electricity system highlight incentives for uncoordinated policies that lower welfare and increase emissions relative to coordination

A Novel, Contactless, Portable “Spot-Check” Device Accurately Measures Respiratory Rate

Respiratory rate (RR) is an important vital sign used in the assessment of acutely ill patients. It is also used as to predict serious deterioration in a patient's clinical condition. Convenient electronic devices exist for measurement of pulse, blood pressure, oxygen saturation and temperature. Although devices which measure RR exist, none has entered everyday clinical practice. We developed a contactless portable respiratory rate monitor (CPRM) and evaluated the agreement in respiratory rate measurements between existing methods and our new device. The CPRM uses thermal anemometry to measure breath signals during inspiration and expiration. RR data were collected from 52 healthy adult volunteers using respiratory inductance plethysmography (RIP) bands (established contact method), visual counting of chest movements (established non-contact method) and the CPRM (new method), simultaneously. Two differently shaped funnel attachments were evaluated for each volunteer. Data showed good agreement between measurements from the CPRM and the gold standard RIP, with intra-class correlation coefficient (ICC): 0.836, mean difference 0.46 and 95% limits of agreement of -5.90 to 6.83. When separate air inlet funnels of the CPRM were analysed, stronger agreement was seen with an elliptical air inlet; ICC 0.908, mean difference 0.37 with 95% limits of agreement -4.35 to 5.08. A contactless device for accurately and quickly measuring respiratory rate will be an important triage tool in the clinical assessment of patients. More testing is needed to explore the reasons for outlying measurements and to evaluate in the clinical setting

New Goldstone multiplet for partially broken supersymmetry

The partial spontaneous breaking of rigid N=2 supersymmetry implies the existence of a massless N=1 Goldstone multiplet. In this paper we show that the spin-(1/2,1) Maxwell multiplet can play this role. We construct its full nonlinear transformation law and find the invariant Goldstone action. The spin-1 piece of the action turns out to be of Born-Infeld type, and the full superfield action is duality invariant. This leads us to conclude that the Goldstone multiplet can be associated with a D-brane solution of superstring theory for p=3. In addition, we find that N=1 chirality is preserved in the presence of the Goldstone-Maxwell multiplet. This allows us to couple it to N=1 chiral and gauge field multiplets. We find that arbitrary Kahler and superpotentials are consistent with partially broken N=2 supersymmetry.Comment: Latex, 13 pages. Version to appear in Phys. Rev.

Some Inconvenient Truths About Climate Change Policy: The Distributional Impacts of Transportation Policies

Instead of efficiently pricing greenhouse gases, policy makers have favored measures that implicitly or explicitly subsidize low carbon fuels. We simulate a transportation-sector cap & trade program (CAT) and three policies currently in use: ethanol subsidies, a renewable fuel standard (RFS), and a low carbon fuel standard (LCFS). Our simulations confirm that the alternatives to CAT are quite costly–2.5 to 4 times more expensive. We provide evidence that the persistence of these alternatives in spite of their higher costs lies in the political economy of carbon policy. The alternatives to CAT exhibit a feature that make them amenable to adoption–a right skewed distribution of gains and losses where many counties have small losses, but a smaller share of counties gain considerably–as much as $6,800 per capita, per year. We correlate our estimates of gains from CAT and the RFS with Congressional voting on the Waxman-Markey cap & trade bill, H.R. 2454. Because Waxman-Markey (WM) would weaken the RFS, House members likely viewed the two policies as competitors. Conditional on a district's CAT gains, increases in a district's RFS gains are associated with decreases in the likelihood of voting for WM. Furthermore, we show that campaign contributions are correlated with a district's gains under each policy and that these contributions are correlated with a Member's vote on WM.

Fast and Fourier: Extreme Mass Ratio Inspiral Waveforms in the Frequency Domain

Extreme Mass Ratio Inspirals (EMRIs) are one of the key sources for future space-based gravitational wave interferometers. Measurements of EMRI gravitational waves are expected to determine the characteristics of their sources with sub-percent precision. However, their waveform generation is challenging due to the long duration of the signal and the high harmonic content. Here, we present the first ready-to-use Schwarzschild eccentric EMRI waveform implementation in the frequency domain for use with either graphics processing units (GPUs) or central processing units (CPUs). We present the overall waveform implementation and test the accuracy and performance of the frequency domain waveforms against the time domain implementation. On GPUs, the frequency domain waveform takes in median $0.044$ seconds to generate and is twice as fast to compute as its time domain counterpart when considering massive black hole masses $\geq 2 \times 10^6 \,{\rm M_\odot}$ and initial eccentricities $e_0 > 0.2$. On CPUs, the median waveform evaluation time is $5$ seconds, and it is five times faster in the frequency domain than in the time domain. Using a sparser frequency array can further speed up the waveform generation, reaching up to $0.3$ seconds. This enables us to perform, for the first time, EMRI parameter inference with fully relativistic waveforms on CPUs. Future EMRI models which encompass wider source characteristics (particularly black hole spin and generic orbit geometries) will require significantly more harmonics. Frequency-domain models will be essential analysis tools for these astrophysically realistic and important signals.Comment: 23 pages, 6 figure