Analog of the Clauser-Horne-Shimony-Holt inequality for steering

The Clauser-Horne-Shimony-Holt (CHSH) inequality (and its permutations), are necessary and sufficient criteria for Bell nonlocality in the simplest Bell-nonlocality scenario: 2 parties, 2 measurements per party and 2 outcomes per measurement. Here we derive an inequality for EPR-steering that is an analogue of the CHSH, in that it is necessary and sufficient in this same scenario. However, since in the case of steering the device at Bob's site must be specified (as opposed to the Bell case in which it is a black box), the scenario we consider is that where Alice performs two (black-box) dichotomic measurements, and Bob performs two mutually unbiased qubit measurements. We show that this inequality is strictly weaker than the CHSH, as expected, and use it to decide whether a recent experiment [Phys. Rev. Lett. 110, 130401 (2013).] involving a single-photon split between two parties has demonstrated EPR-steering.Comment: Expanded v2, new results, new figure. 9 pages, 2 figure

The TRENDS High-Contrast Imaging Survey. VI. Discovery of a Mass, Age, and Metallicity Benchmark Brown Dwarf

The mass and age of substellar objects are degenerate parameters leaving the evolutionary state of brown dwarfs ambiguous without additional information. Theoretical models are normally used to help distinguish between old, massive brown dwarfs and young, low mass brown dwarfs but these models have yet to be properly calibrated. We have carried out an infrared high-contrast imaging program with the goal of detecting substellar objects as companions to nearby stars to help break degeneracies in inferred physical properties such as mass, age, and composition. Rather than using imaging observations alone, our targets are pre-selected based on the existence of dynamical accelerations informed from years of stellar radial velocity (RV) measurements. In this paper, we present the discovery of a rare benchmark brown dwarf orbiting the nearby ($d=18.69\pm0.19$ pc), solar-type (G9V) star HD 4747 ([Fe/H]=$-0.22\pm0.04$) with a projected separation of only $\rho=11.3\pm0.2$ AU ($\theta \approx$ 0.6"). Precise Doppler measurements taken over 18 years reveal the companion's orbit and allow us to place strong constraints on its mass using dynamics ($m \sin(i) = 55.3\pm1.9M_J$). Relative photometry ($\Delta K_s=9.05\pm0.14$, $M_{K_s}=13.00\pm0.14$, $K_s - L' = 1.34\pm0.46$) indicates that HD 4747 B is most-likely a late-type L-dwarf and, if near the L/T transition, an intriguing source for studying cloud physics, variability, and polarization. We estimate a model-dependent mass of $m=72^{+3}_{-13}M_J$ for an age of $3.3^{+2.3}_{-1.9}$ Gyr based on gyrochronology. Combining astrometric measurements with RV data, we calculate the companion dynamical mass ($m=60.2\pm3.3M_J$) and orbit ($e=0.740\pm0.002$) directly. As a new mass, age, and metallicity benchmark, HD 4747 B will serve as a laboratory for precision astrophysics to test theoretical models that describe the emergent radiation of brown dwarfs.Comment: Accepted to Ap

Spatial regression modeling via the R2D2 framework

Spatially dependent data arises in many applications, and Gaussian processes are a popular modelling choice for these scenarios. While Bayesian analyses of these problems have proven to be successful, selecting prior distributions for these complex models remains a difficult task. In this work, we propose a principled approach for setting prior distributions on model variance components by placing a prior distribution on a measure of model fit. In particular, we derive the distribution of the prior coefficient of determination. Placing a beta prior distribution on this measure induces a generalized beta prime prior distribution on the global variance of the linear predictor in the model. This method can also be thought of as shrinking the fit towards the intercept-only (null) model. We derive an efficient Gibbs sampler for the majority of the parameters and use Metropolis-Hasting updates for the others. Finally, the method is applied to a marine protection area data set. We estimate the effect of marine policies on biodiversity and conclude that no-take restrictions lead to a slight increase in biodiversity and that the majority of the variance in the linear predictor comes from the spatial effect.\vspace{12pt

Modeling the release of CO2 in the deep ocean

The idea of capturing and disposing of carbon dioxide (CO2) from the flue gas of fossil fuel-fired power plants has recently received attention as a possible mitigation strategy to counteract potential global warming due to the "greenhouse effect." One specific scheme is to concentrate the CO2 in the flue gas to over 90 mol %, compress and dehydrate the CO2 to supercritical conditions, and then transport it through a pipeline for deep ocean disposal. In Golomb et al. (1989), this scheme was studied, with emphasis on the CO 2 capture aspects. In this follow-on study, we concentrate on the mechanisms of releasing the CO 2 in the deep ocean.Golomb et al. only considered the release of individual liquid CO 2 droplets in the region below 500 m. In this study, we consider all depths in both the liquid and vapor regions, and we model the entire plume in addition to individual droplets or bubbles. The key design variables in the model that can be controlled are: (1) release depth, (2) number of diffuser ports, N, and (3) initial bubble or droplet radius, ro. The results show that we can lower the height of the plume by increasing the number of diffuser ports and/or decreasing the initial bubble or droplet radius. Figure S-1 summarizes the results for a release depth of 500 m. With reasonable values for N and r. of 10 and 1 cm respectively, we can keep the plume height under 100 m. Since our goal is to dissolve all the CO2 before it reaches the well-mixed surface layer at approximately 100 m, we can release our C02 at depths as shallow as 200 m. However, the residence time of the sequestered CO2 in the ocean is also a function of depth. For releases of CO2 less than 500 m deep, we can estimate a residence time of less than 50 years, and for a release from about 1000 m, a residence time from 200 to 300 years. These residence times may be increased by releasing in areas of downwelling or by forming solid CO 2-hydrates which will sink to the ocean floor. For depths greater than 500 m, CO2-hydrates may form but we have ignored them due to lack of data.We estimate that the local CO2 concentration will increase about 0.2 kg/m 3 . Added to the background concentration of 0.1 kg/m 3 , the resulting total concentration will be about 0.3 kg/m 3 , much less than saturation levels of about 40 kg/m 3 . Similarly, SO2 and NOx concentration increases will be about 1 .10 - 3 kg/m3 and 2 10- 4 kg/m 3 , respectively. Given an ambient current of 10 cm/s, horizontal dispersion will dilute these concentration increases by a factor of two at a distance of about 4 km downstream.In implementing a CO2 capture and sequester scheme based on an air separation/ flue gas recycle power plant, the price of electricity would double. The reasons for this doubling are: (1) 44% due to derating of the power plant because of the parasitic power required to capture C02, mainly for air separation and CO compression, (2) 42% due to capital charges and operation and maintenance costs (excluding fuel) of the power plant modifications, including air separation and CO2 compression, and (3) 14% due to capital charges and operation and maintenance costs of a 160 km pipeline for deep ocean disposal. These numbers assume that no additional control measures are required to mitigate potential environmental problems are associated with deep ocean disposal of CO02.Funded by the Mitsubishi Research Insitute, Society and Technology Dept

Duloxetine in the management of chronic musculoskeletal pain

Chronic musculoskeletal pain is among the most frequent painful complaints that healthcare providers address. The bulk of these complaints are chronic low back pain and chronic osteoarthritis. Osteoarthritis is the most common form of arthritis in the United States. It is a chronic degenerative disorder characterized by a loss of cartilage, and occurs most often in older persons. The management of osteoarthritis and chronic low back pain may involve both nonpharmacologic (eg, weight loss, resistive and aerobic exercise, patient education, cognitive behavioral therapy) and pharmacologic approaches. Older adults with severe osteoarthritis pain are more likely to take analgesics than those with less severe pain. The pharmacologic approaches to painful osteoarthritis remain controversial, but may include topical as well as oral nonsteroidal antiinflammatory drugs, acetaminophen, duloxetine, and opioids. The role of duloxetine for musculoskeletal conditions is still evolving

What Makes Agricultural Intensification Profitable for Mozambican Smallholders? An Appraisal of the Inputs Subsector and the 1996/97 DNER/SG2000 Program

This report summarizes an appraisal of input utilization and marketing in Mozambique, focusing on the following research questions: (1) What are current smallholder yields for major commodities, and what is the potential for increasing yields through the use of improved technologies? (2) To what extent are improved technologies already being used by smallholders, and is the use of improved technologies profitable? (3) How are improved seeds, fertilizer and pesticides currently produced and distributed? and (4) What are the key constraints and opportunities for increasing the use of improved technologies by smallholders?food security, food policy, improved technologies, Farm Management, Downloads July 2008-July 2009: 9, O31,

Is Agricultural Intensification Profitable For Mozambican Smallholders? An Appraisal of the Inputs Subsector and the 1996/97 DNER/Sg2000 Program

Farm Management, Downloads July 2008-June 2009: 5,

An Empirically Derived Three-Dimensional Laplace Resonance in the Gliese 876 Planetary System

We report constraints on the three-dimensional orbital architecture for all four planets known to orbit the nearby M dwarf Gliese 876 based solely on Doppler measurements and demanding long-term orbital stability. Our dataset incorporates publicly available radial velocities taken with the ELODIE and CORALIE spectrographs, HARPS, and Keck HIRES as well as previously unpublished HIRES velocities. We first quantitatively assess the validity of the planets thought to orbit GJ 876 by computing the Bayes factors for a variety of different coplanar models using an importance sampling algorithm. We find that a four-planet model is preferred over a three-planet model. Next, we apply a Newtonian MCMC algorithm to perform a Bayesian analysis of the planet masses and orbits using an n-body model in three-dimensional space. Based on the radial velocities alone, we find that a 99% credible interval provides upper limits on the mutual inclinations for the three resonant planets ($\Phi_{cb}<6.20^\circ$ for the "c" and "b" pair and $\Phi_{be}<28.5^\circ$ for the "b" and "e" pair). Subsequent dynamical integrations of our posterior sample find that the GJ 876 planets must be roughly coplanar ($\Phi_{cb}<2.60^\circ$ and $\Phi_{be}<7.87^\circ$), suggesting the amount of planet-planet scattering in the system has been low. We investigate the distribution of the respective resonant arguments of each planet pair and find that at least one argument for each planet pair and the Laplace argument librate. The libration amplitudes in our three-dimensional orbital model supports the idea of the outer-three planets having undergone significant past disk migration.Comment: 19 pages, 11 figures, 8 tables. Accepted to MNRAS. Posterior samples available at https://github.com/benelson/GJ87