The Role of Peer Irrigators on the Choice and Intensity of Use of Irrigation Techniques

The use and the proportion of farmland that uses prominent irrigation practices in Arkansas were evaluated. A bivariate sample selection model evaluated the determinants of the share of irrigated land in a farm that uses each practice. In addition, the relationship between the irrigation practices a peer uses and the use and intensity of five common irrigation practices was evaluated. If a peer of an Arkansas farmer used center pivot irrigation, this increased the probability that the farmer used center pivot irrigation by 66 percentage points. A peer that used pivot irrigation decreased the proportion of irrigated land that used flowmeter by 0.05. However, a peer using computerized hole selection increased the proportion of irrigated land on a farm using irrigation scheduling by 2.20. The peer effect variables were modeled with interactions for location and farm practices of a farm to examine heterogeneity in the peer relationship. A peer using computerized hole selection increased the likelihood a farmer used computerized hole selection by 55 percentage points, but if the farmer is in the south Arkansas Delta, the likelihood of using the practice increased an additional 60 percentage points. The irrigation practices in use by Arkansas farmers’ families and friends affect the decision to use and the proportion of irrigated land that uses center pivot, scientific scheduling, and computerized hole selection

Optimal Entanglement Enhancement for Mixed States

We consider the actions of protocols involving local quantum operations and classical communication (LQCC) on a single system consisting of two separated qubits. We give a complete description of the orbits of the space of states under LQCC and characterise the representatives with maximal entanglement of formation. We thus obtain a LQCC entanglement concentration protocol for a single given state (pure or mixed) of two qubits which is optimal in the sense that the protocol produces, with non-zero probability, a state of maximal possible entanglement of formation. This defines a new entanglement measure, the maximum extractable entanglement.Comment: Final version: to appear in Phys. Rev. Let

The Arecibo Legacy Fast ALFA Survey: VI. Second HI Source Catalog of the Virgo Cluster Region

We present the third installment of HI sources extracted from the Arecibo Legacy Fast ALFA extragalactic survey. This dataset continues the work of the Virgo ALFALFA catalog. The catalogs and spectra published here consist of data obtained during the 2005 and 2006 observing sessions of the survey. The catalog consists of 578 HI detections within the range 11h 36m < R.A.(J2000) < 13h 52m and +08 deg < Dec.(J2000) < +12 deg, and cz_sun < 18000 km/s. The catalog entries are identified with optical counterparts where possible through the examination of digitized optical images. The catalog detections can be classified into three categories: (a) detections of high reliability with S/N > 6.5; (b) high velocity clouds in the Milky Way or its periphery; and (c) signals of lower S/N which coincide spatially with an optical object and known redshift. 75% of the sources are newly published HI detections. Of particular note is a complex of HI clouds projected between M87 and M49 that do not coincide with any optical counterparts. Candidate objects without optical counterparts are few. The median redshift for this sample is 6500 km/s and the cz distribution exhibits the local large scale structure consisting of Virgo and the background void and the A1367-Coma supercluster regime at cz_sun ~7000 km/s. Position corrections for telescope pointing errors are applied to the dataset by comparing ALFALFA continuum centroid with those cataloged in the NRAO VLA Sky Survey. The uncorrected positional accuracy averages 27 arcsec ~(21 arcsec ~median) for all sources with S/N > 6.5 and is of order ~21 arcsec ~(16 arcsec ~median) for signals with S/N > 12. Uncertainties in distances toward the Virgo cluster can affect the calculated HI mass distribution.Comment: 25 pages, 1 Table, 8 figures, Accepted by the Astronomical Journa

Long-Term Effects of HVLA and Exercise vs. Exercise Alone for Adults with Chronic LBP

Introduction & Purpose Chronic low back pain is among the leading causes of disability globally and continues to have a high reoccurrence rate within the first year of treatment. The treatment cost of low back pain has become an increased burden on the healthcare system and patients at an estimated $100 billion per year. With incidence and economic burden of LBP on the rise, physical therapy has been shown to be an efficient and costeffective treatment. Previous research shows improvements to pain and function following HVLA mobilization and exercise in short-term outcomes (\u3c 3 months), but there is limited evidence showing the long-term effects (\u3e 6 months.) PICO: In adults with chronic low back pain, is HVLA mobilization combined with exercise more effective than exercise alone to improve pain and function in the longterm

Reconfigurable ferromagnetic liquid droplets.

Solid ferromagnetic materials are rigid in shape and cannot be reconfigured. Ferrofluids, although reconfigurable, are paramagnetic at room temperature and lose their magnetization when the applied magnetic field is removed. Here, we show a reversible paramagnetic-to-ferromagnetic transformation of ferrofluid droplets by the jamming of a monolayer of magnetic nanoparticles assembled at the water-oil interface. These ferromagnetic liquid droplets exhibit a finite coercivity and remanent magnetization. They can be easily reconfigured into different shapes while preserving the magnetic properties of solid ferromagnets with classic north-south dipole interactions. Their translational and rotational motions can be actuated remotely and precisely by an external magnetic field, inspiring studies on active matter, energy-dissipative assemblies, and programmable liquid constructs

Vortex circulation patterns in planar microdisk arrays

We report a magnetic X-ray microscopy study of the pattern formation of circulation in arrays of magnetic vortices ordered in a hexagonal and a honeycomb lattice. In the honeycomb lattice, we observe at remanence an ordered phase of alternating circulations, whereas in the hexagonal lattice, small regions of alternating lines form. A variation in the edge-to-edge distance shows that the size of those regions scales with the magnetostatic interaction. Micromagnetic simulations reveal that the patterns result from the formation of flux closure states during the nucleation process