191 research outputs found

    Variational quantum iterative power algorithms for global optimization

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    We introduce a family of variational quantum algorithms called quantum iterative power algorithms (QIPA) that outperform existing hybrid near-term quantum algorithms of the same kind. We demonstrate the capabilities of QIPA as applied to three different global-optimization numerical experiments: the ground-state optimization of the H2H_2 molecular dissociation, search of the transmon qubit ground-state, and biprime factorization. Since our algorithm is hybrid, quantum/classical technologies such as error mitigation and adaptive variational ansatzes can easily be incorporated into the algorithm. Due to the shallow quantum circuit requirements, we anticipate large-scale implementation and adoption of the proposed algorithm across current major quantum hardware.Comment: 17 pages, 7 figure

    Photostability studies of ketoconazole: isolation and structural elucidation of the main photodegradation products

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    The purpose of this study was to obtain information on the photochemical properties of ketoconazole, an antifungal agent. Photodegradation of ketoconazole in solution and shampoo under exposure to UV-C (254 nm) and UV-A (352 nm) radiations as well as daylight was monitored by HPLC. Separation of ketoconazole from its degradation products was obtained with monoisopropylamine - methanol (2:500 v/v) and amonium acetate- water (1:200 w/v) (7:3 v/v) as mobile phase on a LiChrospher® 100 column RP-8, 5 μm (150 mm x 4.6 mm) and a flow rate of 1 ml/min. The main protodegradation products: (cis-1-acetyl-4-{4-[[2-(2-chlorophenyl)-2-(1H-imidazol-1-ylmethyl)-1,3- dioxolan-4-yl]methoxy]phenyl}piperazine and (cis-1-acetyl-4-{4-[[2-(4-chlorophenyl)-2-(1H-imidazol- 1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl} piperazine, were isolated and characterized by HPLC-MS and NMR spectrometry. The results indicated photodechlorination of ketoconazole when exposed to light and a significant decrease in antifungal activity.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    From Motion to Emotion : Accelerometer Data Predict Subjective Experience of Music

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    Music is often discussed to be emotional because it reflects expressive movements in audible form. Thus, a valid approach to measure musical emotion could be to assess movement stimulated by music. In two experiments we evaluated the discriminative power of mobile-device generated acceleration data produced by free movement during music listening for the prediction of ratings on the Geneva Emotion Music Scales (GEMS-9). The quality of prediction for different dimensions of GEMS varied between experiments for tenderness (R12(first experiment) = 0.50, R22(second experiment) = 0.39), nostalgia (R12 = 0.42, R22 = 0.30), wonder (R12 = 0.25, R22 = 0.34), sadness (R12 = 0.24, R22 = 0.35), peacefulness (R12 = 0.20, R22 = 0.35) and joy (R12 = 0.19, R22 = 0.33) and transcendence (R12 = 0.14, R22 = 0.00). For others like power (R12 = 0.42, R22 = 0.49) and tension (R12 = 0.28, R22 = 0.27) results could be almost reproduced. Furthermore, we extracted two principle components from GEMS ratings, one representing arousal and the other one valence of the experienced feeling. Both qualities, arousal and valence, could be predicted by acceleration data, indicating, that they provide information on the quantity and quality of experience. On the one hand, these findings show how music-evoked movement patterns relate to music-evoked feelings. On the other hand, they contribute to integrate findings from the field of embodied music cognition into music recommender systems

    Integrating isotopes and documentary evidence : dietary patterns in a late medieval and early modern mining community, Sweden

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    We would like to thank the Archaeological Research Laboratory, Stockholm University, Sweden and the Tandem Laboratory (Ångström Laboratory), Uppsala University, Sweden, for undertaking the analyses of stable nitrogen and carbon isotopes in both human and animal collagen samples. Also, thanks to Elin Ahlin Sundman for providing the δ13C and δ15N values for animal references from Västerås. This research (Bäckström’s PhD employment at Lund University, Sweden) was supported by the Berit Wallenberg Foundation (BWS 2010.0176) and Jakob and Johan Söderberg’s foundation. The ‘Sala project’ (excavations and analyses) has been funded by Riksens Clenodium, Jernkontoret, Birgit and Gad Rausing’s Foundation, SAU’s Research Foundation, the Royal Physiographic Society of Lund, Berit Wallenbergs Foundation, Åke Wibergs Foundation, Lars Hiertas Memory, Helge Ax:son Johnson’s Foundation and The Royal Swedish Academy of Sciences.Peer reviewedPublisher PD

    Minocycline Synergizes with N-Acetylcysteine and Improves Cognition and Memory Following Traumatic Brain Injury in Rats

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    Background: There are no drugs presently available to treat traumatic brain injury (TBI). A variety of single drugs have failed clinical trials suggesting a role for drug combinations. Drug combinations acting synergistically often provide the greatest combination of potency and safety. The drugs examined (minocycline (MINO), N-acetylcysteine (NAC), simvastatin, cyclosporine A, and progesterone) had FDA-approval for uses other than TBI and limited brain injury in experimental TBI models. Methodology/Principal Findings: Drugs were dosed one hour after injury using the controlled cortical impact (CCI) TBI model in adult rats. One week later, drugs were tested for efficacy and drug combinations tested for synergy on a hierarchy of behavioral tests that included active place avoidance testing. As monotherapy, only MINO improved acquisition of the massed version of active place avoidance that required memory lasting less than two hours. MINO-treated animals, however, were impaired during the spaced version of the same avoidance task that required 24-hour memory retention. Coadministration of NAC with MINO synergistically improved spaced learning. Examination of brain histology 2 weeks after injury suggested that MINO plus NAC preserved white, but not grey matter, since lesion volume was unaffected, yet myelin loss was attenuated. When dosed 3 hours before injury, MINO plus NAC as single drugs had no effect on interleukin-1 formation; together they synergistically lowered interleukin-1 levels. This effect on interleukin-1 was not observed when th

    Using the value creation framework to capture knowledge co-creation and pathways to impact in a transnational community of practice in autism education

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    Although theories around Communities of Practice have gained significant ground in recent years and have become an important focus for organizational development, there is a gap in studies that investigate what members gain from participation in these communities. This paper explains how the value creation framework was implemented in a transnational research and development project in autism education by examining cycles of value creation and drawing on two types of data identified by Wenger and colleagues. The value creation framework is a theoretically driven framework to assess social learning in communities. Participants involved in the learning space were co-researchers engaged in a process of investigating, sharing and reflecting on their practice. The paper discusses the methodological challenges and strengths of using the value creation framework, with a particular focus on how insights and interactions led to subsequent changes in the practice of the participants. This work has the potential to make an important contribution to methods and analysis in assessing social learning and pathways to impact in participatory research and development projects more broadly

    Sub region-specific modulation of synchronous neuronal burst firing after a kainic acid insult in organotypic hippocampal cultures

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    <p>Abstract</p> <p>Background</p> <p>Excitotoxicity occurs in a number of pathogenic states including stroke and epilepsy. The adaptations of neuronal circuits in response to such insults may be expected to play an underlying role in pathogenesis. Synchronous neuronal firing can be induced in isolated hippocampal slices and involves all regions of this structure, thereby providing a measure of circuit activity. The effect of an excitotoxic insult (kainic acid, KA) on Mg<sup>2+</sup>-free-induced synchronized neuronal firing was tested in organotypic hippocampal culture by measuring extracellular field activity in CA1 and CA3.</p> <p>Results</p> <p>Within 24 hrs of the insult regional specific changes in neuronal firing patterns were evident as: (i) a dramatic <it>reduction </it>in the ability of CA3 to generate firing; and (ii) a contrasting <it>increase </it>in the frequency and duration of synchronized neuronal firing events in CA1. Two distinct processes underlie the increased propensity of CA1 to generate synchronized burst firing; a lack of ability of the CA3 region to 'pace' CA1 resulting in an increased frequency of synchronized events; and a change in the 'intrinsic' properties limited to the CA1 region, which is responsible for increased event duration. Neuronal quantification using NeuN immunoflurescent staining and stereological confocal microscopy revealed no significant cell loss in hippocampal sub regions, suggesting that changes in the properties of neurons within this region were responsible for the KA-mediated excitability changes.</p> <p>Conclusion</p> <p>These results provide novel insight into adaptation of hippocampal circuits following excitotoxic injury. KA-mediated disruption of the interplay between CA3 and CA1 clearly increases the propensity to synchronized firing in CA1.</p
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