2,786 research outputs found

    Event series prediction via non-homogeneous Poisson process modelling

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    Data streams whose events occur at random arrival times rather than at the regular, tick-tock intervals of traditional time series are increasingly prevalent. Event series are continuous, irregular and often highly sparse, differing greatly in nature to the regularly sampled time series traditionally the concern of hard sciences. As mass sets of such data have become more common, so interest in predicting future events in them has grown. Yet repurposing of traditional forecasting approaches has proven ineffective, in part due to issues such as sparsity, but often due to inapplicable underpinning assumptions such as stationarity and ergodicity. In this paper we derive a principled new approach to forecasting event series that avoids such assumptions, based upon: 1. the processing of event series datasets in order to produce a parameterized mixture model of non-homogeneous Poisson processes; and 2. application of a technique called parallel forecasting that uses these processes’ rate functions to directly generate accurate temporal predictions for new query realizations. This approach uses forerunners of a stochastic process to shed light on the distribution of future events, not for themselves, but for realizations that subsequently follow in their footsteps

    Factors influencing multiple sclerosis disease-modifying treatment prescribing decisions in the United Kingdom: A qualitative interview study

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    Background The proportion of people with relapsing-remitting multiple sclerosis prescribed disease modifying treatments (DMTs) in the United Kingdom (UK) is considered low compared with other countries. There are differences in DMT prescription rates between UK nations (England, Wales, Scotland, Northern Ireland). Despite this, there has been little research into decision-making processes and prescribing practices. Objective To investigate views and experiences of neurologists prescribing DMTs and MS specialist nurses to identify factors influencing prescribing. Methods Semi-structured interviews with 18 consultant neurologists and 16 specialist nurses from diverse settings across the four UK nations. Data were analysed using thematic framework analysis. Results Prescribing practices are influenced by organisational prescribing “cultures”, informal “benchmarking” within peer networks, and prior experience with different DMTs. Health professionals differ in their perceptions of benefits and risks of DMTs and personal “thresholds” for discerning relapses and determining eligibility for DMTs. Prescribers in England felt most constrained by guidelines. Conclusion To achieve equity in access to DMTs for people with MS eligible for treatment, there is a need for public discussion acknowledging differences in health professionals’ interpretations of “relapses” and guidelines and perceptions of DMTs, variation in organisational prescribing “cultures”, and whether the prevailing culture sufficiently meets patients’ needs

    The Use of Elastin-like Polypeptides as a Drug Carrier Material: A Compatibility Study

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    Stimuli responsive self-assembling nanoparticles of elastin-like polypeptides are promising platforms for targeted drug delivery and release. These particles spontaneously assemble from elastin-like polypeptide building blocks in solution. The nanoparticles stably self-assemble under specific temperature, salt, and pH conditions and can dissociate upon changing of these conditions. With appropriate design, the surface of the particles can be decorated with labels that cause them to accumulate in specific diseased tissues. In addition, the size of the particles is appropriate to minimize undesirable rapid clearance from the body. In this study, we are testing the ability of the elastin-like polypeptide core to store and release drugs and model drugs with differing chemical properties. Three chemotherapeutic compounds were loaded into the core of the nanoparticles and the release profile of the drug was determined under conditions that disrupt the particle. This release was compared to baseline release profile of the drug. This study is important in establishing the ability of ELP based nanoparticles to act as triggered drug release vehicles.https://engagedscholarship.csuohio.edu/u_poster_2014/1029/thumbnail.jp

    Pion Breather States in QCD

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    We describe a class of pionic breather solutions (PBS) which appear in the chiral lagrangian description of low-energy QCD. These configurations are long-lived, with lifetimes greater than 10310^3 fm/c, and could arise as remnants of disoriented chiral condensate (DCC) formation at RHIC. We show that the chiral lagrangian equations of motion for a uniformly isospin-polarized domain reduce to those of the sine-gordon model. Consequently, our solutions are directly related to the breather solutions of sine-gordon theory in 3+1 dimensions. We investigate the possibility of PBS formation from multiple domains of DCC, and show that the probability of formation is non-negligible.Comment: 9 pages, 4 figure

    Lifetime of a Disoriented Chiral Condensate

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    The lifetime of a disoriented chiral condensate formed within a heat bath of pions is calculated assuming temperatures and densities attainable at present and future heavy-ion colliders. A generalization of the reduction formula to include coherent states allows us to derive a formula for the decay rate. We predict the half-life to be between 4 and 7 fm/c, depending on the assumed pion density. We also calculate the lifetime in the presence of higher resonances and baryons, which shortens the lifetime by at most 20%.Comment: 9 pages, 3 figures, REVTeX, Eq. (3) modifie

    First records of the spider wasps Ctenocerus Dahlbom and Paraclavelia Haupt from Asia, with discussions on the systematics of Ctenocerinae (Hymenoptera: Pompilidae)

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    We describe two new species of Ctenocerinae (Pompilidae) from Asia, i.e., Ctenocerus srilankae Shimizu sp. nov. from Sri Lanka and Paraclavelia arabiae Shimizu sp. nov. from Oman. These represent the first records of Ctenocerus Dahlbom, 1845 and Paraclavelia Haupt, 1930 in Asia. Two new combinations and a new synonymy are proposed: Ctenocerus fasciatus (Smith, 1851) (= Micropteryx fasciata Smith, 1851); Paraclavelia decipiens (Arnold, 1932) (= Clavelia decipiens Arnold, 1932); and Ctenocerus Dahlbom, 1845 (= Euclavelia Arnold, 1932). We discuss the difficulty of systematics of Ctenocerinae at generic level. The head and pronotal structures of Ctenocerus and Paraclavelia are presumably specialized for preying on trapdoor spiders. These structures are considered to have evolved independently of other unrelated parasitoid Pompilidae that have been confirmed or proposed to prey on trapdoor spiders. We also discuss the biogeographical distribution of these genera

    Alternatively folded proteins with unexpected beneficial functions

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    HAMLET (human alpha-lactalbumin made lethal to tumour cells) and its related partially unfolded protein-fatty acid complexes are novel biomolecular nanoparticles that possess relatively selective cytotoxic activities towards tumour cells. One of the key characteristics is the requirement for the protein to be partially unfolded, hence endowing native proteins with additional functions in the alternatively folded states. Beginning with the history of its discovery and development, the cellular targets that appear to be strongly correlated with tumour cell death are introduced in the present article
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