THE FEDERAL SUGAR PROGRAM AND ITS IMPACT ON CONSUMERS

Agricultural and Food Policy,

Disentanglement and decoherence in two-spin and three-spin systems under dephasing

We compare disentanglement and decoherence rates within two-spin and three-spin entangled systems subjected to all possible combinations of local and collective pure dephasing noise combinations. In all cases, the bipartite entanglement decay rate is found to be greater than or equal to the dephasing-decoherence rates and often significantly greater. This sharpens previous results for two-spin systems [T. Yu and J. H. Eberly Phys. Rev. B 68, 165322 (2003)] and extends them to the three-spin context.Comment: 17 page

Coherent State Quantum Key Distribution with Entanglement Witnessing

An entanglement witness approach to quantum coherent state key distribution and a system for its practical implementation are described. In this approach, eavesdropping can be detected by a change in sign of either of two witness functions, an entanglement witness S or an eavesdropping witness W. The effects of loss and eavesdropping on system operation are evaluated as a function of distance. Although the eavesdropping witness W does not directly witness entanglement for the system, its behavior remains related to that of the true entanglement witness S. Furthermore, W is easier to implement experimentally than S. W crosses the axis at a finite distance, in a manner reminiscent of entanglement sudden death. The distance at which this occurs changes measurably when an eavesdropper is present. The distance dependance of the two witnesses due to amplitude reduction and due to increased variance resulting from both ordinary propagation losses and possible eavesdropping activity is provided. Finally, the information content and secure key rate of a continuous variable protocol using this witness approach are given

Thermal convection in mono-disperse and bi-disperse granular gases: A simulation study

We present results of a simulation study of inelastic hard-disks vibrated in a vertical container. An Event-Driven Molecular Dynamics method is developed for studying the onset of convection. Varying the relevant parameters (inelasticity, number of layers at rest, intensity of the gravity) we are able to obtain a qualitative agreement of our results with recent hydrodynamical predictions. Increasing the inelasticity, a first continuous transition from the absence of convection to one convective roll is observed, followed by a discontinuous transition to two convective rolls, with hysteretic behavior. At fixed inelasticity and increasing gravity, a transition from no convection to one roll can be evidenced. If the gravity is further increased, the roll is eventually suppressed. Increasing the number of monolayers the system eventually localizes mostly at the bottom of the box: in this case multiple convective rolls as well as surface waves appear. We analyze the density and temperature fields and study the existence of symmetry breaking in these fields in the direction perpendicular to the injection of energy. We also study a binary mixture of grains with different properties (inelasticity or diameters). The effect of changing the properties of one of the components is analyzed, together with density, temperature and temperature ratio fields. Finally, the presence of a low-fraction of quasi-elastic impurities is shown to determine a sharp transition between convective and non-convective steady states.Comment: 11 pages, 12 figures, accepted for publication on Physical Review

Female entrepreneurship

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Intruders in the Dust: Air-Driven Granular Size Separation

Using MRI and high-speed video we investigate the motion of a large intruder particle inside a vertically shaken bed of smaller particles. We find a pronounced, non-monotonic density dependence, with both light and heavy intruders moving faster than those whose density is approximately that of the granular bed. For light intruders, we furthermore observe either rising or sinking behavior, depending on intruder starting height, boundary condition and interstitial gas pressure. We map out the phase boundary delineating the rising and sinking regimes. A simple model can account for much of the observed behavior and show how the two regimes are connected by considering pressure gradients across the granular bed during a shaking cycle.Comment: 5 pages, 4 figure

Addressing Mental Health with the Somali Population in the Twin Cities Area

Minnesota is home to one of the highest populations of Somali heritage in North America. Mental illness is reported to be prevalent in this population and there is an underutilization of available mental health services. The purpose of this study was to see how health providers can better identify and discuss mental illness with the Somali community to improve utilization rates of mental health clinics in the Twin Cities area. To do this, six qualitative interviews were conducted with participants who at the time were currently working with Somalis, in a hospital, clinic, or health care agency setting. Content Analysis was used as a method of analysis to identify and interpret themes found from the recorded interviews. The main themes that emerged were: 1) prevalence and recognizing mental illness; 2) the stigma of mental illness; 3) impact of interpreters; and, 4) dialoging about mental health. Findings confirm previous research studies in that there is little uniformity between health professionals on what treatments to recommend to improve utilization. However, findings showed that being culturally aware, building rapport, and discussing mental illness in terms of physical symptoms, all improve utilization rates of Mental Health Services. Somali Americans access medical health through hospitals, clinics, and health care agencies. Because of this, it is important for health care professionals to be culturally aware of Somalis and how to mutually discuss mental illness due to their access to this population

Addressing Mental Health with the Somali Population in the Twin Cities Area

Minnesota is home to one of the highest populations of Somali heritage in North America. Mental illness is reported to be prevalent in this population and there is an underutilization of available mental health services. The purpose of this study was to see how health providers can better identify and discuss mental illness with the Somali community to improve utilization rates of mental health clinics in the Twin Cities area. To do this, six qualitative interviews were conducted with participants who at the time were currently working with Somalis, in a hospital, clinic, or health care agency setting. Content Analysis was used as a method of analysis to identify and interpret themes found from the recorded interviews. The main themes that emerged were: 1) prevalence and recognizing mental illness; 2) the stigma of mental illness; 3) impact of interpreters; and, 4) dialoging about mental health. Findings confirm previous research studies in that there is little uniformity between health professionals on what treatments to recommend to improve utilization. However, findings showed that being culturally aware, building rapport, and discussing mental illness in terms of physical symptoms, all improve utilization rates of Mental Health Services. Somali Americans access medical health through hospitals, clinics, and health care agencies. Because of this, it is important for health care professionals to be culturally aware of Somalis and how to mutually discuss mental illness due to their access to this population

A new algorithm for recognizing the unknot

The topological underpinnings are presented for a new algorithm which answers the question: `Is a given knot the unknot?' The algorithm uses the braid foliation technology of Bennequin and of Birman and Menasco. The approach is to consider the knot as a closed braid, and to use the fact that a knot is unknotted if and only if it is the boundary of a disc with a combinatorial foliation. The main problems which are solved in this paper are: how to systematically enumerate combinatorial braid foliations of a disc; how to verify whether a combinatorial foliation can be realized by an embedded disc; how to find a word in the the braid group whose conjugacy class represents the boundary of the embedded disc; how to check whether the given knot is isotopic to one of the enumerated examples; and finally, how to know when we can stop checking and be sure that our example is not the unknot.Comment: 46 pages. Published copy, also available at http://www.maths.warwick.ac.uk/gt/GTVol2/paper9.abs.htm