438 research outputs found

    Weird Rag

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    Woman dancing near flowers with large cloud in backgroundhttps://scholarsjunction.msstate.edu/cht-sheet-music/12725/thumbnail.jp

    Speed \u27Er Up

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    Two cars racing with plane abovehttps://scholarsjunction.msstate.edu/cht-sheet-music/2716/thumbnail.jp

    The Dublin Rag

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    Photo of Murphy; illustration of black and green decorationshttps://scholarsjunction.msstate.edu/cht-sheet-music/5108/thumbnail.jp

    High-order Discretization of a Gyrokinetic Vlasov Model in Edge Plasma Geometry

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    We present a high-order spatial discretization of a continuum gyrokinetic Vlasov model in axisymmetric tokamak edge plasma geometries. Such models describe the phase space advection of plasma species distribution functions in the absence of collisions. The gyrokinetic model is posed in a four-dimensional phase space, upon which a grid is imposed when discretized. To mitigate the computational cost associated with high-dimensional grids, we employ a high-order discretization to reduce the grid size needed to achieve a given level of accuracy relative to lower-order methods. Strong anisotropy induced by the magnetic field motivates the use of mapped coordinate grids aligned with magnetic flux surfaces. The natural partitioning of the edge geometry by the separatrix between the closed and open field line regions leads to the consideration of multiple mapped blocks, in what is known as a mapped multiblock (MMB) approach. We describe the specialization of a more general formalism that we have developed for the construction of high-order, finite-volume discretizations on MMB grids, yielding the accurate evaluation of the gyrokinetic Vlasov operator, the metric factors resulting from the MMB coordinate mappings, and the interaction of blocks at adjacent boundaries. Our conservative formulation of the gyrokinetic Vlasov model incorporates the fact that the phase space velocity has zero divergence, which must be preserved discretely to avoid truncation error accumulation. We describe an approach for the discrete evaluation of the gyrokinetic phase space velocity that preserves the divergence-free property to machine precision

    Modern Warfare: An M and S Examination of the Dynamic Impact of Warlords and Insurgents on State Stability

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    9/11 changed the world as we knew it. Part of this change was to redirect the military of the United States away from focusing primarily on conventional conflict to a primary focus on unconventional or irregular conflict. This change required a tremendous learning effort by the military and their supporting research and development community. This learning effort included relearning of old but largely forgotten lessons as well as acquiring newly discovered knowledge. During the process of our immediate 9/11 response, we identified that we were engaged in Iraq and Afghanistan in an insurgency. Subsequently, our focus converged upon the description of insurgencies and the requirements for counterinsurgency. This paper argues that emerging conditions now allow the re-evaluation of the type of conflict occurring today and into the foreseeable future: that we, including the modeling and simulation world, emerge from a singular focus on orthodox insurgencies and start to consider the consequences and opportunities of the complexity of current conflicts. As an example of complexity, this paper will use the relatively common phenomenon of the Warlord or Warlordism. The paper will provide a definition of this phenomenon and then describe the implications for modelers. The paper will conclude by demonstrating the impact of incorporating this one rather prosaic complexity into an insurgency model, using agent based modeling (ABM)

    First in Man Studies of Pharmacokinetic Profiles of a Novel Oral PTH(1-34)

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    Background: PTH(1-34) (Teriparatide) is an anabolic agent used in treatment of osteoporosis. It promotes bone formation and reduces the risk of vertebral and some non-vertebral fractures. The route of administration by daily subcutaneous (sc) injection can cause problems in certain patients. A new oral delivery system for human PTH(1-34) has been developed as a possible treatment option. Galitzer et al. presented pre-clinical data (ASBMR 2012, MO0402) and first-in-human results (ASBMR 2013, FR0378) on safety, tolerability and absorption dynamics of oral PTH(1-34) in various dosages. We now describe the pharmacokinetics (PK) of oral PTH(1-34) compared to sc and placebo in healthy subjects. Objective: A single-center, double blinded, triple crossover study was designed to compare the 1.8 mg optimal dose of oral PTH(1-34) against standard dosage of teriparatide injection and oral placebo. Method: The study was conducted following and in accordance with the Hadassah Medical Center ethical approval committee. 12 healthy volunteers (6m/6f), 18-50y, received three treatments: single sc injection of 20”g FORTEOÂź, 1.8 mg oral PTH(1-34), or placebo. Blood samples were collected at time 0, 10, 15, 20, 30, 45, 60, 75, 90, 120, 180, 240, 300 minute post dose. Plasma concentration of PTH(1-34) (IDS, Tyne and Wear, UK) and cyclic adenosine 3’,5’monophosphate (cAMP) were measured on all samples. Results: All 12 subjects on oral PTH(1-34) showed rapid, post dose increase then decrease of PTH(1-34), from baseline mean (±SD) of 5.9 (1.8) pg/mL to peak mean of 185.3 (±128.8) pg/mL. PK profiles of oral PTH(1-34) showed Cmax (pg/mL), Tmax (mins), AUC0-last of 238.3 (110.8), 17.5 (5.4) and 6161.7 (2726.7), respectively; whereas sc showed mean Cmax (pg/mL), Tmax (mins), AUC0-last of 172.3 (55.7), 20.8 (8.7) and 13965.9 (2984.8), respectively. Plasma cAMP increased in all subjects in response to oral PTH(1-34) and sc treatment. Serum adjusted calcium in all subjects remained within normal limits throughout the studies. Conclusion: PK profiles showed a single oral dose of 1.8 mg PTH(1-34) is rapidly absorbed, and no significant difference in Cmax and Tmax when compared with 20”g of sc teriparatide. A significant difference in the rate of plasma clearance and AUC0-last value was observed (fig.1). These differing profiles and modality of administration of PTH(1-34) could offer unique advantages in the treatment of calcium and metabolic bone disorders

    Enhanced bioavailability and reduced pharmacokinetic variability of Oral PTH (1-34) in man

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    An orally administered PTH may have prodigious advantages in the treatment of hypoparathyroidism and osteoporosis. Unfortunately, the oral delivery of biologic macromolecules is characterized by a negligible bioavailability and a high dose-to-dose variability in absorption, resulting in difficulty in accurately titrating the drug effect. We present clinical study data of a novel oral peptide delivery technology demonstrating an enhanced bioavailability with reduced Cmax variability. Methods: A Phase I, open label crossover pharmacokinetic (PK) study to assess the safety and PK of oral PTH (1-34) in ten healthy male adult volunteers was conducted. The PK profile of a fixed dose - 1.5mg PTH (1-34) of three different oral formulations was compared. PTH (1-34) levels in the plasma of subjects was analyzed at a number of time points post administration, utilizing a PTH (1-34) immunoassay (IDS; Bolden, UK). In parallel, to assess the pharmacodynamic (PD) effect, serum calcium of subjects receiving the different formulations of oral PTH (1-34) was analyzed. Results: PK profiles of all oral PTH (1-34) formulations were characterized by a rapid absorption and elimination. The systemic exposure (AUC) of the basic oral formulation and two modified formulation versions were 3481 ±1843 pg*min/mL, 7976 ±2556 pg*min/mL and 11369 ±3719 pg*min/mL (mean ± SE). The maximal plasma concentration (Cmax) of these formulations were 145 ±56pg/mL, 375 ±108pg/mL, and 481 ±101pg/mL, respectively. Cmax coefficients of variation (CV%) of the same formulations were 123%, 91% and 67%, respectively. Similarly to the drug absorption, PD response of the modified formulations, presented as the maximal relative increase in albumin adjusted calcium, was improved from 0.07 ±0.29mg/dL to 0.32 ±0.24mg/dL. Discussion: Inherent to oral drug delivery of biopharmaceuticals is the extremely low bioavailability and high absorption variability. The current results indicate that Entera’s delivery technology can overcome these two principal obstacles by achieving repeatable, clinically relevant systemic drug exposure. Entera’s proprietary delivery platform was optimized and achieved anenhancement in drug bioavailability in parallel with the significant decrease in its absorption variability. Similarly, its effect on blood calcium was enhanced by the novel oral formulation of PTH (1-34) pointing out the potential of the drug to be a first line treatment of hypoparathyroidism and osteoporosis
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