1,411 research outputs found

    SINMAP 2.0 - A Stability Index Approach to Terrain Stability Hazard Mapping, User\u27s Manual

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    SINMAP 2.0 (Stability Index MAPping) is an ArcGIS 9.0 plug-in that implements the computation and mapping of a slope stability index based upon geographic information, primarily digital elevation data. This report describes the theoretical basis for the calculation of the stability index, describes the implementation, presents several case studies and describes use of the accompanying software. SINMAP has its theoretical basis in the infinite plane slope stability model with wetness (pore pressures) obtained from a topographically based steady state model of hydrology. Digital elevation model (DEM) methods are used to obtain the necessary input information (slope and specific catchment area). Parameters are allowed to be uncertain following uniform distributions between specified limits. These may be adjusted (and calibrated) for geographic ccalibration regionsd based upon soil, vegetation or geologic data. The methodology includes an interactive visual calibration that adjusts parameters while referring to observed landslides. The calibration involves adjustment of parameters so that the stability map ccapturesd a high proportion of observed landslides in regions with low stability index, while minimizing the extent of low stability regions and consequent alienation of terrain to regions where landslides have not been observed. This calibration is done while simultaneously referring to the stability index map, a specific catchment area and slope plot (of landslide and non landslide points) where lines distinguish the zones categorized into the different stability classes and a table giving summary statistics. The current implementation of SINMAP 2.0 is a plug-in to the ArcGIS ArcMap geographic information system (GIS) from Environmental Systems Research Institute, Inc. (ESRI). This utilizes ArcMap for its standard GIS functionality such as the input and organization of data and the presentation and output of results. SINMAP is grid based, requiring ArcGIS version 9.0 or higher

    Wide-bandwidth, tunable, multiple-pulse-width optical delays using slow light in cesium vapor

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    We demonstrate an all-optical delay line in hot cesium vapor that tunably delays 275 ps input pulses up to 6.8 ns and 740 input ps pulses up to 59 ns (group index of approximately 200) with little pulse distortion. The delay is made tunable with a fast reconfiguration time (hundreds of ns) by optically pumping out of the atomic ground states.Comment: 4 pages, 6 figure

    Information theoretic approach to interactive learning

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    The principles of statistical mechanics and information theory play an important role in learning and have inspired both theory and the design of numerous machine learning algorithms. The new aspect in this paper is a focus on integrating feedback from the learner. A quantitative approach to interactive learning and adaptive behavior is proposed, integrating model- and decision-making into one theoretical framework. This paper follows simple principles by requiring that the observer's world model and action policy should result in maximal predictive power at minimal complexity. Classes of optimal action policies and of optimal models are derived from an objective function that reflects this trade-off between prediction and complexity. The resulting optimal models then summarize, at different levels of abstraction, the process's causal organization in the presence of the learner's actions. A fundamental consequence of the proposed principle is that the learner's optimal action policies balance exploration and control as an emerging property. Interestingly, the explorative component is present in the absence of policy randomness, i.e. in the optimal deterministic behavior. This is a direct result of requiring maximal predictive power in the presence of feedback.Comment: 6 page

    Boundary Conditions on Internal Three-Body Wave Functions

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    For a three-body system, a quantum wave function Ψm\Psi^\ell_m with definite \ell and mm quantum numbers may be expressed in terms of an internal wave function χk\chi^\ell_k which is a function of three internal coordinates. This article provides necessary and sufficient constraints on χk\chi^\ell_k to ensure that the external wave function Ψm\Psi^\ell_m is analytic. These constraints effectively amount to boundary conditions on χk\chi^\ell_k and its derivatives at the boundary of the internal space. Such conditions find similarities in the (planar) two-body problem where the wave function (to lowest order) has the form rmr^{|m|} at the origin. We expect the boundary conditions to prove useful for constructing singularity free three-body basis sets for the case of nonvanishing angular momentum.Comment: 41 pages, submitted to Phys. Rev.

    1950: Abilene Christian College Bible Lectures - Full Text

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    Introduction We offer with interest and pleasure another volume of a great series of discourses delivered at Abilene Christian College. The following were given in February, 1950. The first of these Lectureships was held in the year 1919, and was published by the Firm Foundation Publishing House in book form. With little exception they have appeared each year since that time. The printing was done by others a few times. Those who are fortunate enough to have a complete set of these fine gospel sermons are possessed of a treasure in religious literature. Only a few of the later years can now be supplied. The rest are numbered among the “rare books” and we frequently have calls for them, but of course cannot supply them. Any reader having a copy for sale is requested to write the office of the Firm Foundation at Austin, Texas. The “Lectureship” of Abilene Christian College has become a great annual affair to the churches of Christ; thousands are in attendance, many of them coming from Canada and other countries besides all over the United States. This annual “mass meeting” must not be understood to be a “Convention” of the churches of Christ. We have no such conventions and do not endorse them. The Lectureship is simply a feature in the work of Abilene Christian College, a series of gospel sermons to which friends and patrons of the school and others are invited. It is our hope that the contents of this book may enrich the life, and strengthen the faith of the reader. G. H. F. SHOWALTER Austin, Texas August 20, 195

    Degradation versus self-assembly of block copolymer micelles

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    The stability of micelles self-assembled from block copolymers can be altered by the degradation of the blocks. Slow degradation shifts the equilibrium size distribution of block copolymer micelles and change their properties. Quasi-equilibrium scaling theory shows that the degradation of hydrophobic blocks in the core of micelles destabilize the micelles reducing their size, while the degradation of hydrophilic blocks forming coronas of micelles favors larger micelles and may, at certain conditions, induce the formation of micelles from individual chains.Comment: Published in Langmuir http://pubs.acs.org/doi/pdf/10.1021/la204625

    Distinct cortical and striatal actions of a β-arrestin-biased dopamine D2 receptor ligand reveal unique antipsychotic-like properties.

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    The current dopamine (DA) hypothesis of schizophrenia postulates striatal hyperdopaminergia and cortical hypodopaminergia. Although partial agonists at DA D2 receptors (D2Rs), like aripiprazole, were developed to simultaneously target both phenomena, they do not effectively improve cortical dysfunction. In this study, we investigate the potential for newly developed β-arrestin2 (βarr2)-biased D2R partial agonists to simultaneously target hyper- and hypodopaminergia. Using neuron-specific βarr2-KO mice, we show that the antipsychotic-like effects of a βarr2-biased D2R ligand are driven through both striatal antagonism and cortical agonism of D2R-βarr2 signaling. Furthermore, βarr2-biased D2R agonism enhances firing of cortical fast-spiking interneurons. This enhanced cortical agonism of the biased ligand can be attributed to a lack of G-protein signaling and elevated expression of βarr2 and G protein-coupled receptor (GPCR) kinase 2 in the cortex versus the striatum. Therefore, we propose that βarr2-biased D2R ligands that exert region-selective actions could provide a path to develop more effective antipsychotic therapies

    Adaptation and delivery of a motivational interviewing-based counseling program for persons acutely infected with HIV in Malawi: Implementation and lessons learned

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    Objective: Individuals diagnosed with acute HIV infection (AHI) are highly infectious and require immediate HIV prevention efforts to minimize their likelihood of transmitting HIV to others. We sought to explore the relevance of Motivational Interviewing (MI), an evidence-based counseling method, for Malawians with AHI. Methods: We designed a MI-based intervention called “Uphungu Wanga” to support risk reduction efforts immediately after AHI diagnosis. It was adapted from Options and SafeTalk interventions, and refined through formative research and input from Malawian team members and training participants. We conducted qualitative interviews with counselors and participants to explore the relevance of MI in this context. Results: Intervention adaptation required careful consideration of Malawian cultural context and the needs of people with AHI. Uphungu Wanga's content was relevant and key MI techniques of topic selection and goal setting were viewed positively by counselors and participants. However, rating levels of importance and confidence did not appear to help participants to explore behavior change as intended. Conclusion: Uphungu Wanga may have provided some added benefits beyond “brief education” standard of care counseling for Malawians with AHI. Practice implications: MI techniques of topic selection and goal setting may enhance prevention education and counseling for Malawians with AHI
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