1,919 research outputs found

    The role of controllability in optimizing quantum dynamics

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    This paper discusses the important role of controllability played on the complexity of optimizing quantum mechanical control systems. The study is based on a topology analysis of the corresponding quantum control landscape, which is referred to as the optimization objective as a functional of control fields. We find that the degree of controllability is closely relevant with the ruggedness of the landscape, which determines the search efficiency for global optima. This effect is demonstrated via the gate fidelity control landscape of a system whose controllability is restricted on a SU(2) dynamic symmetry group. We show that multiple local false traps (i.e., non-global suboptima) exist even if the target gate is realizable and that the number of these traps is increased by the loss of controllability, while the controllable systems are always devoid of false traps.Comment: 13 pages, 3 figure

    The inhibitor of differentiation-2 promotes synovial fibroblast-dependent osteoclastogenesis in rheumatoid arthritis

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    Objectives: Despite indirect evidence suggesting that low oxygen levels might occur in the rheumatoid arthritis (RA) synovium, direct proof of the presence of hypoxia in the arthritic synovium as well as the relevance of low oxygen levels for joint destruction is lacking. The aim of this study was to analyse the distribution of hypoxia in arthritic joints and to evaluate the molecular effects of the hypoxic environment on the phenotype of RA synovial fibroblasts (SF).<p></p> Methods: The hypoxia marker EF-5 was applied in mice with the collagen-induced arthritis (CIA). Expression profile analysis with hypoxic and normoxic SF was performed using subtractive hybridization and microarray. The expression of the inhibitor of differentiation-2 (Id-2), CD68 (macrophage marker) and prolyl hydroxylase (fibroblast marker) was evaluated by immunohistochemistry on synovial tissues from RA, osteoarthritis patients and CIA mice. To evaluate the function of Id-2 in SF, cells were transfected with the pcDNA3.1 containing cDNA for Id-2 or Id-2-specific siRNA or mock controls. The expression of Id-2 and genes regulated by Id-2 in transfected SF was evaluated by SYBR Green real-time PCR and western blot. SF stably transfected with Id-2 were cocultured with bone marrow cells in a transwell system. The expression of the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin were measured by real-time PCR. The development of osteoclasts was evaluated by visualization of the activity of tartrate-resistant acid phosphatase.<p></p> Results: Using the hypoxia marker EF-5 we found that in mice with CIA, synovial cells invading bone and cartilage are exposed to reduced oxygen levels. Expression profile studies identified Id-2 as being upregulated under low oxygen conditions. In addition, IL-1beta stimulation increased the expression of Id-2 in these cells. Histological studies of RA synovium and CIA synovium showed strong expression of Id-2 in SF at sites of synovial invasion into bone. Overproduction of Id-2 in SF by stable transfection triggered the expression of several genes promoting osteoclastogenesis, including BMP-2, PTHrP, Wnt5a and vascular endothelial growth factor. Conversely, the suppression of endogenous Id-2 led to the downregulation of the expression of these molecules. Consistent with these findings coculture of Id-2 transfected SF with bone marrow cells increased the expression of the osteoclast differentiation factor RANKL, and decreased the expression of the osteoclast inhibitory factor osteoprotegerin in bone marrow stromal cells, which was followed by an increase in the number of osteoclasts.<p></p> Conclusion: Taken together, our data provide evidence that hypoxia is present at sites of synovial invasion in RA and that Id-2 induced by hypoxia contributes at these sites to joint destruction by promoting SF-dependent osteoclastogenesis

    Economic and environmental strategic water management in the shale gas industry: Application of cooperative game theory

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    In this work, a mixed‐integer linear programming (MILP) model is developed to address optimal shale gas‐water management strategies among shale gas companies that operate relatively close. The objective is to compute a distribution of water‐related costs and profit among shale companies to achieve a stable agreement on cooperation among them that allows increasing total benefits and reducing total costs and environmental impacts. We apply different solution methods based on cooperative game theory: The Core, the Dual Core, the Shapley value, and the minmax Core. We solved different case studies including a large problem involving four companies and 207 wells. In this example, individual cost distribution (storage cost, freshwater withdrawal cost, transportation cost, and treatment cost) assigned to each player is included. The results show that companies that adopt cooperation strategies improve their profits and enhance the sustainability of their operations through the increase in recycled water.The authors gratefully acknowledge the financial support by the Ministry of Economy, Industry, and Competitiveness from Spain, under the projects CTQ2016-77968-C3-1-P and CTQ2016-77968-C3-2-P (AEI/FEDER, UE)

    Crossings, Motzkin paths and Moments

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    Kasraoui, Stanton and Zeng, and Kim, Stanton and Zeng introduced certain qq-analogues of Laguerre and Charlier polynomials. The moments of these orthogonal polynomials have combinatorial models in terms of crossings in permutations and set partitions. The aim of this article is to prove simple formulas for the moments of the qq-Laguerre and the qq-Charlier polynomials, in the style of the Touchard-Riordan formula (which gives the moments of some qq-Hermite polynomials, and also the distribution of crossings in matchings). Our method mainly consists in the enumeration of weighted Motzkin paths, which are naturally associated with the moments. Some steps are bijective, in particular we describe a decomposition of paths which generalises a previous construction of Penaud for the case of the Touchard-Riordan formula. There are also some non-bijective steps using basic hypergeometric series, and continued fractions or, alternatively, functional equations.Comment: 21 page

    Carbon monoxide production from five volatile anesthetics in dry sodalime in a patient model: halothane and sevoflurane do produce carbon monoxide; temperature is a poor predictor of carbon monoxide production

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    BACKGROUND: Desflurane and enflurane have been reported to produce substantial amounts of carbon monoxide (CO) in desiccated sodalime. Isoflurane is said to produce less CO and sevoflurane and halothane should produce no CO at all. The purpose of this study is to measure the maximum amounts of CO production for all modern volatile anesthetics, with completely dry sodalime. We also tried to establish a relationship between CO production and temperature increase inside the sodalime. METHODS: A patient model was simulated using a circle anesthesia system connected to an artificial lung. Completely desiccated sodalime (950 grams) was used in this system. A low flow anesthesia (500 ml/min) was maintained using nitrous oxide with desflurane, enflurane, isoflurane, halothane or sevoflurane. For immediate quantification of CO production a portable gas chromatograph was used. Temperature was measured within the sodalime container. RESULTS: Peak concentrations of CO were very high with desflurane and enflurane (14262 and 10654 ppm respectively). It was lower with isoflurane (2512 ppm). We also measured small concentrations of CO for sevoflurane and halothane. No significant temperature increases were detected with high CO productions. CONCLUSION: All modern volatile anesthetics produce CO in desiccated sodalime. Sodalime temperature increase is a poor predictor of CO production

    Phytochemicals Analysis and Medicinal Potentials of Hydroalcoholic Extract from Curtisia dentata (Burm.f) C.A. Sm Stem Bark

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    Curtisia dentata (CD) is a vulnerable medicinal plant used for the treatment of stomach ailments in South Africa. However, there is a lack of sufficient data on its phytochemical components and medicinal properties. The phytochemical analysis of the extract was estimated using standard assay methods while its antibacterial activity was determined by the agar dilution method against selected bacteria. The antioxidant activity of the extract was done using ferric reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid (ABTS), nitric oxide (NO), hydrogen peroxide (H2O2) and lipid peroxidation (LPO). The cytotoxicity assay of the extract was assessed using the brine shrimp lethality test with LC50 value of 0.302 mg/mL. The antibacterial activity of the extract demonstrated an appreciable broad spectrum activity against the tested bacteria with minimum inhibitory concentration (MIC) ranges between 5000 and 0.5 mg/L. Both phenol and flavonoid concentrations were 14.86 mg tannic acid equivalent/g and 13.64 mg quercetin equivalent/g, respectively. The percentage composition of saponins (13.26) was highest, followed by steroids (1.42), while alkaloids and tannins had the same value of 0.51. Similarly, IC50 values of the extract against DPPH, ABTS, H2O2, LPO and NO were 0.017, 0.018, 0.159, 0.06 and 0.052 mg/mL, respectively. The reducing power of the extract was found to be concentration dependent. Our data suggest that the 70% ethanol extract from the CD extract has antibacterial and antioxidant properties due to the presence of bio-active compounds and thus support its folkloric use in the treatment of diseases
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