Durier N.,Independent Research
PloS one | Year: 2012
Treatment of hepatitis C (HCV) is very effective, achieving a cure in 50-90% of patients. Besides its own good for individuals, this most likely translates in reduced transmission, but this phenomenon has yet to be fully explored. In this mathematical modeling study done in the context of Vietnam, we estimated the public health benefit that HCV therapy for injecting drug users (IDUs) may achieve. Treatment coverage of 25, 50 and 75% of chronically HCV-infected IDUs (4 years into infection) is predicted to reduce the chronic HCV viremia prevalence respectively by 21, 37 and 50%, 11 years after full scale up to the intended coverage. At a constant 50% coverage level, earlier treatment, 3, 2, and 1 year into infection is predicted to reduce the chronic HCV viremia prevalence by 46, 60 and 85%. In these later 3 scenarios, for every 100 treatment courses provided, a total of respectively 50, 61 and 94 new infections could be averted. These benefits were projected in the context of current low coverage of methadone maintenance therapy and needles/syringes exchange programs, and these services expansion showed complementary preventive benefits to HCV therapy. The program treatment commitment associated with the various scenarios is deemed reasonable. Our model projections are robust under adjustment for uncertainty in the model parameter values. In this case study in Vietnam, we project that treatment of HCV for injecting drug users will have a preventative herd effect in addition to curing patients in need for therapy, achieving a substantial reduction in HCV transmission and prevalence.
Bootello J.,Independent Research
Advances in Space Research | Year: 2015
This article checks a perturbing gravitational potential, with the orbit dynamics parameters of hyperbolic flyby trajectories. This potential could be consistent with the collected data of flybys after 2005, however with a wide error range. Results are consistent with the post-Newtonian gravitoelectric accelerations, although starting from a different method approach. The dynamic effects of this quantum gravitational perturbing potential, could be modeled as an orbit precession, similar gravitoelectric effect as in close elliptic orbits. © 2015 COSPAR. Published by Elsevier Ltd. All rights reserved.
Loukanova R.,Independent Research
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012
The paper provides introduction into the language, semantics, and the reduction calculus of acyclic recursion. The expressiveness of the theory for conveying semantic information, relevant for applications in active media technologies, is demonstrated by representing naming information. © 2012 Springer-Verlag.
Aretxabaleta A.L.,CSIC - Institute of Marine Sciences |
Smith K.W.,Independent Research
Journal of Marine Systems | Year: 2013
A method is introduced for improved estimation of missing data that preserves the multi-regime characteristics of a dataset. The approach analyzes regime change in spatial time series by applying an Expectation-Maximization algorithm (an iterative procedure that finds the Maximum Likelihood Estimate of statistical model parameters) for the determination of a Gaussian Mixture Model (GMM). We estimate the GMM when only a linear noisy measurement of the underlying process is available. We demonstrate the validity of the method using an idealized dataset and also by applying the method to equatorial sea surface salinity observed by the TAO/TRITON array. A percentage of the total observations is systematically extracted and predicted using the method to allow for validation. Finally, the approach is applied to recently available remote sea surface salinity from the SMOS satellite in the Amazon River plume region. Areas of large noise levels (reduced signal-to-noise ratios) are considered as missing data and predicted with the proposed approach. The method interprets regime changes and provides reconstructions of missing information based on the mean and covariability within each regime. •Optimal estimation of missing data is conducted while preserving multi-regime data character.•Expectation-Maximization is used to separate the components of the date and interpolate missing data.•Validity of the method is demonstrated using idealized and realistic (TAO/TRITON in situ and SMOS satellite) datasets. © 2013 Elsevier B.V.
Loukanova R.,Independent Research
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013
The formal language of acyclic recursion (FLAR) has a distinctive algorithmic expressiveness, which, in addition to computational fundamentals, provides representation of underspecified semantic information. Semantic ambiguities and underspecification of information expressed by human language are problematic for computational semantics, and for natural language processing in general. Pronominal and elliptical expressions in human languages are ubiquitous and major contributors to underspecification in language and other information processing. We demonstrate the capacity of the type theory of for computational semantic underspecification by representing interactions between reflexives, non-reflexive pronominals, and VP ellipses with type theoretic, recursion therms. We present a class of semantic underspecification that propagates and presents in question-answering interactions. The paper introduces a technique for incremental presentation of question-answer interaction. © 2013 Springer-Verlag Berlin Heidelberg.