40 research outputs found

    Capacity of Control for Stochastic Dynamical Systems Perturbed by Mixed Fractional Brownian Motion with Delay in Control

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    In this paper, we discuss the relationships between capacity of control in entropy theory and intrinsic properties in control theory for a class of finite dimensional stochastic dynamical systems described by a linear stochastic differential equations driven by mixed fractional Brownian motion with delay in control. Stochastic dynamical systems can be described as an information channel between the space of control signals and the state space. We study this control to state information capacity of this channel in continuous time. We turned out that, the capacity of control depends on the time of final state in dynamical systems. By using the analysis and representation of fractional Gaussian process, the closed form of continuous optimal control law is derived. The reached optimal control law maximizes the mutual information between control signals and future state over a finite time horizon. The results obtained here are motivated by control to state information capacity for linear systems in both types deterministic and stochastic models that are widely used to understand information flows in wireless network information theory. The contribution of this paper is that we propose some new relationships between control theory and entropy theoretic properties of stochastic dynamical systems with delay in control. Finally, we present an example that serve to illustrate the relationships between capacity of control and intrinsic properties in control theory.Comment: 17 pages, 2 example

    On The Continuous Poisson Distribution

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    Abstract There are no scientific works deal directly and Extensively with the continuous Poisson distribution (CPD). There are some of rare allusions here and there. In this paper we will take this issue on our responsibility. We consider here the continuous Poisson distribution. Different methods to estimate CPD parameters are studied, Maximum Likelihood estimator, Moments estimator, Percentile estimator, least square estimator and weighted least square estimator. An empirical study is conducted to compare among these methods performances. We also consider the generating issue. Other empirical experiments are conducted to build a model for bandwidth parameter which is used for Poisson density estimation

    Generating a Random Dynamical System

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    In this paper we shall create a new random dynamical system from old one. One of the most important of them, is the product of two random dynamical systems, which is also random dynamical system. This technique will be very important to detailed study of the random dynamical system

    Real Separable Hilbert Space

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    Abstract In this paper we presented The existence and stability of inclusion equations type of stochastic dynamical system driven by mixed fractional Brownian motion in a real separable Hilbert space with an illustrative example

    Association Of BCR-ABL Alternative Splice Variants with Disease Progression, Treatment Response and Survival in Chronic Myeloid Leukemia Patients Treated with Firstline imatinib Monotherapy

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    Background: Alternative RNA splicing has diverse biological effects in heath as well as disease. It also contributes to cancer onset and progression. Chronic Myeloid Leukemia (CML) results due to BCR-ABL fusion oncogene that is created due to chromosomal translocation t [9; 22] [q34; q11]). BCR-ABL is target of tyrosine kinase inhibitors (TKIs). BCR-ABL through alternative splicing can generate b2a2, b3a2 and some other rare splicing variants. BCR-ABL variants may vary in their response to TKI treatment and disease progression potential, which is a major factor contributing to dismal treatment outcome in CML. Objective: The objective of this study is to investigate correlation of BCR-ABL splice variants with TKI treatment outcome and survival in three phases of CML that has rarely been studied previously.Methods: BCR-ABL splice variants were studied using reverse transcriptase PCR (RT-PCR). in 70 CML patients from three phases of CML who were receiving imatinib (TKI) treatment.Results: Frequencies of different BCR/ABL splice variants like b3a2, b2a2 and b3a2+b2a2 were 49 (70%), 15 (21.4%) and 6 (8.6%), respectively. Splice variant b2a2 were more common (53.3%) in chronic phase CML (CP-CML) while b3a2 had higher frequency in advanced phases of CML (44.9%). CML patients with b2a2 transcript had better complete cytogenetic response and major molecular response to TKI treatment overall (100% vs. 24.5%) as well as in CP-CML (100% vs. 85.7%) and superior survival when compared to patients with b3a2 splice variant. All patients who died had male gender, less than 33 years age, b3a2 transcript, advanced phases of CML and imatinib resistance.Conclusions: Splice variant b3a2 was associated with CML progression, poorer survival and inferior treatment outcome as compared to b2a2. Further investigations on BCR-ABL splice variants and their roles in CML pathogenesis can provide deeper insights into CML biology and new targets for BCR-ABL positive leukemia treatment.          Keywords: CML; BCR-ABL splice variants; Progression; Survival; Treatment outcome 

    2019 ESC/EAS guidelines for the management of dyslipidaemias : Lipid modification to reduce cardiovascular risk

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    Correction: Volume: 292 Pages: 160-162 DOI: 10.1016/j.atherosclerosis.2019.11.020 Published: JAN 2020Peer reviewe

    Mortality of emergency abdominal surgery in high-, middle- and low-income countries

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    Background: Surgical mortality data are collected routinely in high-income countries, yet virtually no low- or middle-income countries have outcome surveillance in place. The aim was prospectively to collect worldwide mortality data following emergency abdominal surgery, comparing findings across countries with a low, middle or high Human Development Index (HDI). Methods: This was a prospective, multicentre, cohort study. Self-selected hospitals performing emergency surgery submitted prespecified data for consecutive patients from at least one 2-week interval during July to December 2014. Postoperative mortality was analysed by hierarchical multivariable logistic regression. Results: Data were obtained for 10 745 patients from 357 centres in 58 countries; 6538 were from high-, 2889 from middle- and 1318 from low-HDI settings. The overall mortality rate was 1⋅6 per cent at 24 h (high 1⋅1 per cent, middle 1⋅9 per cent, low 3⋅4 per cent; P < 0⋅001), increasing to 5⋅4 per cent by 30 days (high 4⋅5 per cent, middle 6⋅0 per cent, low 8⋅6 per cent; P < 0⋅001). Of the 578 patients who died, 404 (69⋅9 per cent) did so between 24 h and 30 days following surgery (high 74⋅2 per cent, middle 68⋅8 per cent, low 60⋅5 per cent). After adjustment, 30-day mortality remained higher in middle-income (odds ratio (OR) 2⋅78, 95 per cent c.i. 1⋅84 to 4⋅20) and low-income (OR 2⋅97, 1⋅84 to 4⋅81) countries. Surgical safety checklist use was less frequent in low- and middle-income countries, but when used was associated with reduced mortality at 30 days. Conclusion: Mortality is three times higher in low- compared with high-HDI countries even when adjusted for prognostic factors. Patient safety factors may have an important role. Registration number: NCT02179112 (http://www.clinicaltrials.gov)

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
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