Forecasting Metals Returns A Bayesian Decision Theoretic Approach

Turning points in commodity returns are important for decisions of policy makers, commodity producers and consumers reliant on medium term outcomes. However, forecasting of turning points has been a neglected feature of forecasting, especially in commodity markets. I forecast turning points in metals price returns using Bayesian Decision Theory. The method produces a probabilistic statement about our belief of a turning point occurring in the next period which, combined with a decision rule based on a loss function generates optimal turning point forecasts. This method produces positive results in forecasting turning points in metals returns, with the simple linear models investigated producing more accurate turning point forecasts than naive models across a number of different evaluation methods for the general case and for the specific example of a producing firm.

Mechanical CPR devices

It is recognized that the quality of cardiopulmonary resuscitation (CPR) is an important predictor of outcome from cardiac arrest. Mechanical chest-compression devices provide an alternative to manual CPR. Physiological and animal data suggest that mechanical chest-compression devices are more effective than manual CPR. Consequently, there has been much interest in the development of new techniques and devices to improve the efficacy of CPR. This review will consider the evidence and current indications for the use of some of the more common mechanical devices developed to increase the safety and efficacy of CPR administration

CRISPR-guided DNA polymerase enabling diversification of all nucleotides in a tunable window

The capacity to diversify genetic codes advances our understanding and engineering of biological systems. A method to continuously diversify user-defined regions of a genome without requiring the integration of nucleic acid libraries would enable forward genetic approaches in systems not amenable to high efficiency homologydirected integration, rapid evolution of biotechnologically useful activity through accelerated and parallelized rounds of mutagenesis and selection, and cell lineage tracking. Here we developed EvolvR, the first system that can continuously diversify all nucleotides within a tunable window length at user-defined loci. Our results demonstrate that EvolvR enables multiplexed and continuous diversification of user-defined genomic loci that will be useful for a broad range of basic and biotechnological applications

Coral-Excavating Sponge Cliona delitrix: Current Trends of Space Occupation on High Latitude Coral Reefs

The recent increase in abundance of coral-excavating sponges is a threat to the health of coral reefs. However, the distribution and growth of these sponges are poorly documented on high latitude reefs where corals live in marginal environmental conditions. In this study, we characterize the current trends of space occupation of Cliona delitrix on high latitude reefs (26°N) in southeast Florida. C. delitrix densities were significantly higher on the deepest habitat of this reef tract (the outer reef) in response to a higher availability of coral substratum. Sponge growth rates increased with depth, and in relation to presence of tunicates and absence of macroalgae living in the sponge–coral interaction band. Conversely, coral tissue loss was similar between habitats, regardless of the fouling organisms present in the band between sponge and coral. On high latitude reefs, C. delitrix preferred massive scleractinian coral species as substratum, similar to tropical reefs, but its inclination for specific coral species varied. The outer reef sites (deepest habitat) are most vulnerable to C. delitrix colonization. Reef habitats with higher coral densities and more available dead coral may continue to suffer the greatest levels of sponge bioerosion

Free Energies of Isolated 5- and 7-fold Disclinations in Hexatic Membranes

We examine the shapes and energies of 5- and 7-fold disclinations in low-temperature hexatic membranes. These defects buckle at different values of the ratio of the bending rigidity, $\kappa$, to the hexatic stiffness constant, $K_A$, suggesting {\em two} distinct Kosterlitz-Thouless defect proliferation temperatures. Seven-fold disclinations are studied in detail numerically for arbitrary $\kappa/K_A$. We argue that thermal fluctuations always drive $\kappa/K_A$ into an ``unbuckled'' regime at long wavelengths, so that disclinations should, in fact, proliferate at the {\em same} critical temperature. We show analytically that both types of defects have power law shapes with continuously variable exponents in the ``unbuckled'' regime. Thermal fluctuations then lock in specific power laws at long wavelengths, which we calculate for 5- and 7-fold defects at low temperatures.Comment: LaTeX format. 17 pages. To appear in Phys. Rev.

Submillimeter diffusion tensor imaging and late gadolinium enhancement cardiovascular magnetic resonance of chronic myocardial infarction.

BackgroundKnowledge of the three-dimensional (3D) infarct structure and fiber orientation remodeling is essential for complete understanding of infarct pathophysiology and post-infarction electromechanical functioning of the heart. Accurate imaging of infarct microstructure necessitates imaging techniques that produce high image spatial resolution and high signal-to-noise ratio (SNR). The aim of this study is to provide detailed reconstruction of 3D chronic infarcts in order to characterize the infarct microstructural remodeling in porcine and human hearts.MethodsWe employed a customized diffusion tensor imaging (DTI) technique in conjunction with late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) on a 3T clinical scanner to image, at submillimeter resolution, myofiber orientation and scar structure in eight chronically infarcted porcine hearts ex vivo. Systematic quantification of local microstructure was performed and the chronic infarct remodeling was characterized at different levels of wall thickness and scar transmurality. Further, a human heart with myocardial infarction was imaged using the same DTI sequence.ResultsThe SNR of non-diffusion-weighted images was >100 in the infarcted and control hearts. Mean diffusivity and fractional anisotropy (FA) demonstrated a 43% increase, and a 35% decrease respectively, inside the scar tissue. Despite this, the majority of the scar showed anisotropic structure with FA higher than an isotropic liquid. The analysis revealed that the primary eigenvector orientation at the infarcted wall on average followed the pattern of original fiber orientation (imbrication angle mean: 1.96 ± 11.03° vs. 0.84 ± 1.47°, p = 0.61, and inclination angle range: 111.0 ± 10.7° vs. 112.5 ± 6.8°, p = 0.61, infarcted/control wall), but at a higher transmural gradient of inclination angle that increased with scar transmurality (r = 0.36) and the inverse of wall thickness (r = 0.59). Further, the infarcted wall exhibited a significant increase in both the proportion of left-handed epicardial eigenvectors, and in the angle incoherency. The infarcted human heart demonstrated preservation of primary eigenvector orientation at the thinned region of infarct, consistent with the findings in the porcine hearts.ConclusionsThe application of high-resolution DTI and LGE-CMR revealed the detailed organization of anisotropic infarct structure at a chronic state. This information enhances our understanding of chronic post-infarction remodeling in large animal and human hearts