An Empirical Examination of the Relationship Between Real Options Values and the Rate of Investment

This paper examines the relationship between uncertainty and investment decisions by food and non-food firms. Using hysteresis and the real options paradigm, we review why uncertainty might cause firms to delay investment. In particular, our model looks for a negative relationship between capital invested and uncertainty. In the alternative, if the relationship is positive, this may be consistent with the exercise of growth options or competitive markets. Empirical results are mixed. In one of the four models we present there is clear evidence of hysteresis, that is a negative relationship between year over year investment and uncertainty. The remaining 3 models indicate the opposite, a positive relationship between investment and risk. Although the models differ, the first model is the stronger of the three. Nonetheless, the results are ambiguous. Although we use a large cross sectional, time series panel set of data, we find nothing remarkable about the food industry per se, except that across industries, their level of investment is about in the middle.Financial Economics,

Marsviewer 2008

Marsviewer 2008 is designed for quality control, browsing, and operational and science analysis of images and derived image products returned by spacecraft. This program allows all derived products (reduced data records, or RDRs) associated with each original image (experiment data record, or EDR) to be viewed in various ways, including in stereo, depending on the type of image

Interannual sea level variability in the western North Atlantic : regional forcing and remote response

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Geophysical Research Letters 40 (2013): 5915–5919, doi:10.1002/2013GL058013.Annually averaged sea level (1970–2012) measured by tide gauges along the North American east coast is remarkably coherent over a 1700 km swath from Nova Scotia to North Carolina. Satellite altimetry (1993–2011) shows that this coherent interannual variability extends over the Middle Atlantic Bight, Gulf of Maine, and Scotian Shelf to the shelf break where there is a local minimum in sea level variance. Comparison with National Center for Environmental Prediction reanalysis winds suggests that a significant fraction of the detrended sea level variance is forced by the region's along-shelf wind stress. While interannual changes in sea level appear to be forced locally, altimetry suggests that the changes observed along the coast and over the shelf may influence the Gulf Stream path downstream of Cape Hatteras.M. Andres gratefully acknowledges support from the Woods Hole Oceanographic Institution’s Coastal Ocean Institute. G. Gawarkiewicz acknowledges the support of NSF grant OCE-1129125

Sensor corrections for Sea-Bird SBE-41CP and SBE-41 CTDs

Author Posting. © American Meteorological Society, 2007. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Atmospheric and Oceanic Technology 24 (2007): 1117-1130, doi:10.1175/JTECH2016.1.Sensor response corrections for two models of Sea-Bird Electronics, Inc., conductivity–temperature–depth (CTD) instruments (the SBE-41CP and SBE-41) designed for low-energy profiling applications were estimated and applied to oceanographic data. Three SBE-41CP CTDs mounted on prototype ice-tethered profilers deployed in the Arctic Ocean sampled diffusive thermohaline staircases and telemetered data to shore at their full 1-Hz resolution. Estimations of and corrections for finite thermistor time response, time shifts between when a parcel of water was sampled by the thermistor and when it was sampled by the conductivity cell, and the errors in salinity induced by the thermal inertia of the conductivity cell are developed with these data. In addition, thousands of profiles from Argo profiling floats equipped with SBE-41 CTDs were screened to select examples where thermally well-mixed surface layers overlaid strong thermoclines for which standard processing often yields spuriously fresh salinity estimates. Hundreds of profiles so identified are used to estimate and correct for the conductivity cell thermal mass error in SBE-41 CTDs.The National Ocean Partnership Program and the National Oceanic and Atmospheric Administration (NOAA) Office of Oceanic and Atmospheric Research funded this analysis. The ITP data were acquired under National Science Foundation (NSF) Grant OCE0324233

Multienzymatic immobilization of laccases on polymeric microspheres:A strategy to expand the maximum catalytic efficiency

Laccase enzymes of were covalently coimmobilized on poly(glycidyl methacrylate) microspheres. The objective of this work was to create a biocatalyst that works efficiently in a wide range of pH. The coimmobilization was performed using two different strategies to compare the most efficient. The results showed that by correctly selecting the enzymes and concentrations involved in the commobilization, it is possible to obtain a biocatalyst that works efficiently at a wide pH range (2.0-7.0). The maximum activity values reached per gram of support for the obtained biocatalyst were 41.90 U (pH 3.0), 40.89 U (pH 4.0), and 39.54 U (pH 6.0). Moreover, the thermal, storage, and mechanical stabilities were improved compared to the free and single-immobilized laccases. It was concluded that enzymatic coimmobilization is an excellent alternative to obtain a robust biocatalyst that works in a wide pH range, with potential environmental and industrial applications

Rib Fracture Fixation Restores Inspiratory Volume and Peak Flow in a Full Thorax Human Cadaveric Breathing Model

Background: Multiple rib fractures cause significant pain and potential for chest wall instability. Despite an emerging trend of surgical management of flail chest injuries, there are no studies examining the effect of rib fracture fixation on respiratory function. Objectives: Using a novel full thorax human cadaveric breathing model, we sought to explore the effect of flail chest injury and subsequent rib fracture fixation on respiratory outcomes. Patients and Methods: We used five fresh human cadavers to generate negative breathing models in the left thorax to mimic physiologic respiration. Inspiratory volumes and peak flows were measured using a flow meter for all three chest wall states: intact chest, left-sided flail chest (segmental fractures of ribs 3 - 7), and post-fracture open reduction and internal fixation (ORIF) of the chest wall with a pre-contoured rib specific plate fixation system. Results: A wide variation in the mean inspiratory volumes and peak flows were measured between specimens; however, the effect of a flail chest wall and the subsequent internal fixation of the unstable rib fractures was consistent across all samples. Compared to the intact chest wall, the inspiratory volume decreased by 40 ± 19% in the flail chest model (P = 0.04). Open reduction and internal fixation of the flail chest returned the inspiratory volume to 130 ± 71% of the intact chest volumes (P = 0.68). A similar 35 ± 19% decrease in peak flows was seen in the flail chest (P = 0.007) and this returned to 125 ± 71% of the intact chest following ORIF (P = 0.62). Conclusions: Negative pressure inspiration is significantly impaired by an unstable chest wall. Restoring mechanical stability of the fractured ribs improves respiratory outcomes similar to baseline values

A Hamiltonian Formulation for Long Internal Waves

A novel canonical Hamiltonian formalism is developed for long internal waves in a rotating environment. This includes the effects of background vorticity and shear on the waves. By restricting consideration to flows in hydrostatic balance, superimposed on a horizontally uniform background of vertical shear and vorticity, a particularly simple Hamiltonian structure arises, which can be thought of as describing a nonlinearly coupled infinite collection of shallow water systems. The kinetic equation describing the time evolution of the spectral energy of internal waves is subsequently derived, and a stationary Kolmogorov solution is found in the high frequency limit. This is surprisingly close to the Garrett--Munk spectrum of oceanic internal waves

Evolution of a Canada Basin ice-ocean boundary layer and mixed layer across a developing thermodynamically forced marginal ice zone

A comprehensive set of autonomous, ice-ocean measurements were collected across the Canada Basin to study the summer evolution of the ice-ocean boundary layer (IOBL) and ocean mixed layer (OML). Evaluation of local heat and freshwater balances and associated turbulent forcing reveals that melt ponds (MPs) strongly influence the summer IOBL-OML evolution. Areal expansion of MPs in mid-June start the upper ocean evolution resulting in significant increases to ocean absorbed radiative flux (19 W m−2 in this study). Buoyancy provided by MP drainage shoals and freshens the IOBL resulting in a 39 MJ m−2 increase in heat storage in just 19 days (52% of the summer total). Following MP drainage, a near-surface fresh layer deepens through shear-forced mixing to form the summer mixed layer (sML). In late summer, basal melt increases due to stronger turbulent mixing in the thin sML and the expansion of open water areas due in part to wind-forced divergence of the sea ice. Thermal heterogeneities in the marginal ice zone (MIZ) upper ocean led to large ocean-to-ice heat fluxes (100–200 W m−2) and enhanced basal ice melt (3–6 cm d−1), well away from the ice edge. Calculation of the upper ocean heat budget shows that local radiative heat input accounted for at least 89% of the observed latent heat losses and heat storage (partitioned 0.77/0.23). These results suggest that the extensive area of deteriorating sea ice observed away from the ice edge during the 2014 season, termed the “thermodynamically forced MIZ,” was driven primarily by local shortwave radiative forcing