Linking the Climate and Thermal Phase Curve of 55 Cancri e

The thermal phase curve of 55 Cancri e is the first measurement of the temperature distribution of a tidally locked Super-Earth, but raises a number of puzzling questions about the planet's climate. The phase curve has a high amplitude and peak offset, suggesting that it has a significant eastward hot-spot shift as well as a large day-night temperature contrast. We use a general circulation model to model potential climates, and investigate the relation between bulk atmospheric composition and the magnitude of these seemingly contradictory features. We confirm theoretical models of tidally locked circulation are consistent with our numerical model of 55 Cnc e, and rule out certain atmospheric compositions based on their thermodynamic properties. Our best-fitting atmosphere has a significant hot-spot shift and day-night contrast, although these are not as large as the observed phase curve. We discuss possible physical processes which could explain the observations, and show that night-side cloud formation from species such as SiO from a day-side magma ocean could potentially increase the phase curve amplitude and explain the observations. We conclude that the observations could be explained by an optically thick atmosphere with a low mean molecular weight, a surface pressure of several bar and a strong eastward circulation, with night-side cloud formation a possible explanation for the difference between our model and the observations.Comment: Accepted for publication in Ap

AGRICULTURE AND CITIZEN COMPLAINTS

The paper addresses the relationship between agricultural spills and environmental complaints filed by citizens against agriculture. It also determines the influence of other factors on the likelihood of both farm spills and complaints within a region. The relationships have been estimated using a unique data set containing the number of spills and complaints along with regional data such as the stringency of environmental regulations and socio-economic variables. Different environmental regulations do appear to have an effect on the spills and complaints. By-laws on the size of manure storage facility in relation to the number of livestock housed influence the likelihood of spills within a region. Larger storages decrease the number of annual manure applications and thus the opportunity for runoff. While the required distance between a new barn and a waterway appears to have no effect on the likelihood of spills, it does decrease the probability of complaints being lodged against agriculture. Increases in the percentage of the regions zoned as agriculture also decreases the likelihood of complaining. Together the results suggest that distance between livestock producers and both environmentally sensitive areas and people are an effective means to reduce conflicts between farmers and the local community. Another policy question raised in the study was the effectiveness of using citizen complaints as an information tool in addressing environmental quality issues surrounding agriculture. There is a positive, albeit weak, positive influence between spills in a region and the number of complaints. Complaints could be used to indicate problem areas but the information signal will be noisy. Regulators will have to be aware that such complaints are more likely to come from wealthy areas when deciding upon how to react to complaints.Environmental Economics and Policy,

Real exchange rate and asymmetric shocks in the West African Monetary Zone (WAMZ)

This paper examines real effective exchange rate (REER) responses to shocks in exchange rate determinants for the West African Monetary Zone (WAMZ) over the period 1980–2015. The analysis is based on a country-by-country VECM, and oil price, supply and demand shocks are identified using long run restrictions in a structural VAR model. We report significant differences in the response of REER to real oil price, productivity (supply) and demand preference shocks across these economies. In addition the relative contribution of these shocks to REER movements in the short and long run appears to be different across economies. Our findings suggest that the WAMZ countries are structurally different, and asymmetric shocks with inadequate adjustment mechanisms imply that a monetary union would be costly

Non-isothermal X-ray Emitting Gas in Clusters of Galaxies

We have analyzed X-ray spectra from six galaxy clusters which contain cooling flows: A85, A478, A1795, A2142, A2147, & A2199. The X-ray spectra were taken with the HEAO1-A2 Medium and High Energy Detectors and the Einstein Solid State Spectrometer. For each cluster, we simultaneously fit the spectra from these three detectors with models incorporating one or more emission components comprised of either thermal or cooling flow models. Five of the clusters (all but A2142) are better fit by a multi-component model (a cooling flow plus one or two thermal components or a two thermal component model) than by isothermal models. In four of the clusters (A85, A1795, A2147, & A2199), we find evidence for cool gas outside of the canonical cooling flow region. These latter four clusters can be characterized by three temperature components: a temperature inversion in the central region, a hotter region with an emission-weighted temperature which is higher than that of an isothermal model fit to the entire cluster, and a cooler region with an emission-weighted temperature of ~1 keV. The cool component outside the cooling flow region has a large minimum emission measure which we attribute, in part, to diffuse cool gas in the outer cluster atmosphere. If at least some of the cool exterior gas is virialized, this would imply a radially decreasing temperature profile. Together with the density profiles we have found, this leads to a baryon fraction in gas which increases with radius and is larger than that for an isothermal cluster atmosphere. Consequently, if clusters of galaxies trace the mass distribution in the Universe, the gas mass fraction we have calculated for an isothermal gas (which is ~15%) together with the nominal galaxy contribution (~5%) gives a baryon fraction of ~20%. Using the upper limit to the baryon density derived from BigComment: gzipped tar file of 26 PostScript pages, including 2 figures, 7 tables. Also available at http://www.astr.ua.edu/preprints/white/INDEX_READ_ME_1st.htm

Agricultural Applications of Value-at-Risk Analysis: A Perspective

Value-at-Risk (VaR) determines the probability of a portfolio of assets losing a certain amount in a given time period due to adverse market conditions with a particular level of confidence. Value-at-Risk has received considerable attention from financial economists and financial practitioners for its use in risk reporting, in particular the risks of derivatives. This paper provides a "state-of-the-art" review of VaR estimation techniques and empirical findings found in the finance literature. The ability of VaR estimates to represent large losses associated with tail events varies among procedure, confidence level, and data used. To date, there is no consensus to the most appropriate estimation technique. Potential applications of Value-at-Risk are suggested in the context of agricultural risk management. In the wake of the Hedge-to-Arrive crisis, the lifting of agricultural trade options by the CFTC, and the decreased government participation, VaR seems to have a place in the agricultural risk manager's toolkit.Value-at-Risk, risk management, estimation procedures

EVALUATING THE HEDGING POTENTIAL OF THE LEAN HOG FUTURES CONTRACT

The lean hog futures contract is replacing the live hog futures contract at the Chicago Mercantile Exchange beginning with the February 1997 contract. The lean hog futures will be cash settled based on a broad-based lean hog price index, eliminating terminal markets from the price discovery process. Using this index over a twenty-month period as a proxy for the lean hog futures price, this paper compares the hedging effectiveness of the live hog futures contract to the hedging potential of the lean hog futures contract for cash live hogs as well as four cash meat cuts. Frozen pork bellies futures are also examined for the cash meats. Both long-term and short-term hedges are simulated, using the minimum-variance approach, which utilizes only unconditional information, and the Myers-Thompson approach that incorporates conditional information. The results show that the lean hog futures should perform better than either the live hog or the frozen pork bellies futures as a hedging instrument for Omaha cash hogs and cash loins. The strongest evidence of this is for the short-term hedging of cash hogs. For the other three meats, no futures contract demonstrated a clear hedging advantage.Marketing,

The CFHTLS Deep Catalog of Interacting Galaxies I. Merger Rate Evolution to z=1.2

We present the rest-frame optical galaxy merger fraction between 0.2<z<1.2, as a function of stellar mass and optical luminosity, as observed by the Canada-France-Hawaii Telescope Legacy Deep Survey (CFHTLS-Deep). We developed a new classification scheme to identify major galaxy-galaxy mergers based on the presence of tidal tails and bridges. These morphological features are signposts of recent and ongoing merger activity. Through the visual classification of all galaxies, down to i_vega<22.2 (~27,000 galaxies) over 2 square degrees, we have compiled the CFHTLS Deep Catalog of Interacting Galaxies, with ~1600 merging galaxies. We find the merger fraction to be 4.3% +/-0.3% at z~0.3 and 19.0% +/-2.5% at z~1, implying evolution of the merger fraction going as (1+z)^m, with m=2.25 +/-0.24. This result is inconsistent with a mild or non-evolving (m4sigma level of confidence. A mild trend, where massive galaxies with M>10^10.7 M_sun are undergoing fewer mergers than less massive systems M~10^10 M_sun), consistent with the expectations of galaxy assembly downsizing is observed. Our results also show that interacting galaxies have on average SFRs double that found in non-interacting field galaxies. We conclude that (1) the optical galaxy merger fraction does evolve with redshift, (2) the merger fraction depends mildly on stellar mass, with lower mass galaxies having higher merger fractions at z<1, and (3) star formation is triggered at all phases of a merger, with larger enhancements at later stages, consistent with N-body simulations.Comment: e.g.: 17 pages, 14 figures, accepted for publication in Ap

Evaluation of FRAX® score use in Maltese osteoporosis management guidelines

Objectives: Recent years have brought a shift towards evidence-based fracture risk engines. Fracture Risk Assessment Tool (FRAX®) is one such diagnostic tool used to evaluate the ten-year probability of osteoporotic fracture risk. The aim of this study was to evaluate the Maltese FRAX® score-based osteoporosis management guidelines and identify the suitability of using such a risk factor engine-based protocol. Study design: Data from 702 patients presenting for bone mineral density (BMD) estimation in 2010- 2011 were collected. In this period, local guidelines were devised but not yet put into practice so all referred patients underwent BMD estimation. These patients were below 65 years of age and above the minimum age for FRAX® use: 40 years. Data included Age, Weight, Height, BMI and the presence of any risk factor components of the FRAX® score tool. BMD was assessed using Norland/Hologic densitometers. FRAX® scores (excluding BMD) for each patient were calculated using the online tool www.shef.ac.uk/FRAX as accessed in 2014. The resulting major osteoporotic fracture risk was compared to age-specific assessment thresholds as set by Kanis et al. (2013). Thus the appropriateness (or otherwise) of densitometry measurements as dictated by local guidelines was determined. Main outcome measures: The main outcome measures in this study were the femoral neck and vertebral body BMD. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of using the FRAX®-based guidelines in under 65 year olds were calculated. Results: Local guidelines for managing <65 year olds were found to have a PPV of 11.26% and a NPV of 94.38 % Conclusion: FRAX®-guided local guidelines are well suited at excluding non-osteoporotic patients (False omission rate of 5.62 %). Positive likelihood ratio for the protocol was found to be 1.27. This means that 1 in every 8.8 patients that would have been referred for BMD estimation were actually osteoporotic.peer-reviewe

Individualization and Collectivity in Networks of Discursive Cyberspace: A case study on reddit

The diminishing of temporal and spatial boundaries in the contemporary age of connectivity has fully realized Beck, Giddens and Nash’s “reflexive” modernity. This reflexive modernity refers to the diminishing control of traditional institutions on individual lives. In the shift towards loosely bounded networks as the operant mode of socialization, I propose that both collective and self identity become individualized choices. People are able to pick and choose the different aspects of their formative identity as well as the elective communities to share and consume those aspects. Using a convenience sample, I perform a case study on reddit.com to explore how biographical experience and individual performance are critical in navigating online networks and representing the self in discursive cyberspace. I approach identity through the lens of queer theory to develop a fluid understanding on identity formation and practice. I argue that the exchanges that take place in discursive cyberspace are not only meaningful in terms developing networks of alternative knowledges, affective support, and social capital, but are also foundational to reproducing reflexivity and its tendency towards individualization