Non Parametric Distributed Inference in Sensor Networks Using Box Particles Messages

This paper deals with the problem of inference in distributed systems where the probability model is stored in a distributed fashion. Graphical models provide powerful tools for modeling this kind of problems. Inspired by the box particle filter which combines interval analysis with particle filtering to solve temporal inference problems, this paper introduces a belief propagation-like message-passing algorithm that uses bounded error methods to solve the inference problem defined on an arbitrary graphical model. We show the theoretic derivation of the novel algorithm and we test its performance on the problem of calibration in wireless sensor networks. That is the positioning of a number of randomly deployed sensors, according to some reference defined by a set of anchor nodes for which the positions are known a priori. The new algorithm, while achieving a better or similar performance, offers impressive reduction of the information circulating in the network and the needed computation times

How small is too small? A systematic review of center volume and outcome after cardiac transplantation

Background—The aim of this study was to assess the relationship between the volume of cardiac transplantation procedures performed in a center and the outcome after cardiac transplantation. Methods and Results—PubMed, Embase, and the Cochrane library were searched for articles on the volume–outcome relationship in cardiac transplantation. Ten studies were identified, and all adopted a different approach to data analysis and varied in adjustment for baseline characteristics. The number of patients in each study ranged from 798 to 14401, and observed 1-year mortality ranged from 12.6% to 34%. There was no association between the continuous variables of center volume and observed mortality. There was a weak association between the continuous variables of center volume and adjusted mortality up to 1 year and a stronger association at 5 years. When centers were grouped in volume categories, low-volume centers had the highest adjusted mortality, intermediate-volume centers had lower adjusted mortality, and high-volume centers had the lowest adjusted mortality but were not significantly better than intermediate-volume centers. Category limits were arbitrary and varied between studies. Conclusions—There is a relationship between center volume and mortality in heart transplantation. The existence of a minimum acceptable center volume or threshold is unproven. However, a level of 10 to 12 heart transplants per year corresponds to the upper limit of low-volume categories that may have relatively higher mortality. It is not known whether outcomes for patients treated in low-volume transplant centers would be improved by reorganizing centers to ensure volumes in excess of 10 to 12 heart transplants per year

The interplay between tissue growth and scaffold degradation in engineered tissue constructs

In vitro tissue engineering is emerging as a potential tool to meet the high demand for replacement tissue, caused by the increased incidence of tissue degeneration and damage. A key challenge in this field is ensuring that the mechanical properties of the engineered tissue are appropriate for the in vivo environment. Achieving this goal will require detailed understanding of the interplay between cell proliferation, extracellular matrix (ECM) deposition and scaffold degradation.\ud \ud In this paper, we use a mathematical model (based upon a multiphase continuum framework) to investigate the interplay between tissue growth and scaffold degradation during tissue construct evolution in vitro. Our model accommodates a cell population and culture medium, modelled as viscous fluids, together with a porous scaffold and ECM deposited by the cells, represented as rigid porous materials. We focus on tissue growth within a perfusion bioreactor system, and investigate how the predicted tissue composition is altered under the influence of (i) differential interactions between cells and the supporting scaffold and their associated ECM, (ii) scaffold degradation, and (iii) mechanotransduction-regulated cell proliferation and ECM deposition.\ud \ud Numerical simulation of the model equations reveals that scaffold heterogeneity typical of that obtained from μCT scans of tissue engineering scaffolds can lead to significant variation in the flow-induced mechanical stimuli experienced by cells seeded in the scaffold. This leads to strong heterogeneity in the deposition of ECM. Furthermore, preferential adherence of cells to the ECM in favour of the artificial scaffold appears to have no significant influence on the eventual construct composition; adherence of cells to these supporting structures does, however, lead to cell and ECM distributions which mimic and exaggerate the heterogeneity of the underlying scaffold. Such phenomena have important ramifications for the mechanical integrity of engineered tissue constructs and their suitability for implantation in vivo

A Semidefinite Programming approach for minimizing ordered weighted averages of rational functions

This paper considers the problem of minimizing the ordered weighted average (or ordered median) function of finitely many rational functions over compact semi-algebraic sets. Ordered weighted averages of rational functions are not, in general, neither rational functions nor the supremum of rational functions so that current results available for the minimization of rational functions cannot be applied to handle these problems. We prove that the problem can be transformed into a new problem embedded in a higher dimension space where it admits a convenient representation. This reformulation admits a hierarchy of SDP relaxations that approximates, up to any degree of accuracy, the optimal value of those problems. We apply this general framework to a broad family of continuous location problems showing that some difficult problems (convex and non-convex) that up to date could only be solved on the plane and with Euclidean distance, can be reasonably solved with different $\ell_p$-norms and in any finite dimension space. We illustrate this methodology with some extensive computational results on location problems in the plane and the 3-dimension space.Comment: 27 pages, 1 figure, 7 table

Saving energy in aggressive intrusion detection through dynamic latency sensitivity recognition

In an always connected world, cyber-attacks and computer security breaches can produce significant financial damages as well as introduce new risks and menaces in everyday's life. As a consequence, more and more sophisticated packet screening/filtering solutions are deployed everywhere, typically on network border devices, in order to sanitize Internet traffic. Despite the obvious benefits associated to the proactive detection of security threats, these devices, by performing deep packet inspection and inline analysis, may both affect latency-sensitive traffic introducing non-negligible delays, and increase the energy demand at the network element level. Starting from these considerations, we present a selective routing and intrusion detection technique based on dynamic statistical analysis. Our technique separates latency-sensitive traffic from latency-insensitive one and adaptively organizes the intrusion detection activities over multiple nodes. This allows suppressing directly at the network ingress, when possible, all the undesired components of latency-insensitive traffic and distributing on the innermost nodes the security check for latency sensitive flows, prioritizing routing activities over security scanning ones. Our final goal is demonstrating that selective intrusion detection can result in significant energy savings without adversely affecting latency-sensitive traffic by introducing unacceptable processing delays. \ua9 2017 Elsevier Ltd

Combustion and emissions characterization of terpenes with a view to their biological production in cyanobacteria

In developing future fuels there is an opportunity to make use of advances in many fields of science and engineering to ensure that such fuels are sustainable in both production and utilization. One such advance is the use of synthetic biology to re-engineer photosynthetic micro-organisms such that they are able to produce novel hydrocarbons directly from CO2. Terpenes are a class of hydrocarbons that can be produced biologically and have potential as liquid transport fuels. This paper presents experimental studies on a compression ignition engine and spark ignition engine in which the combustion and emissions of 12 different terpenes that could potentially be produced by cyanobacteria were assessed as single components and blends with fossil diesel and fossil gasoline. The 12 terpenes were chosen to explore how small changes to the molecular structure of geraniol (a terpene most easily produced by cyanobacteria) impact on combustion and emissions. Furthermore, the toxicity of some of the best performing terpenes were assessed using the model cyanobacterium Synechocystis sp. PCC6803 (hereafter, Synechocystis) as a prelude to a metabolic engineering programme. The compression ignition engine tests were carried out at constant injection timing and constant ignition timing, and the spark ignition engine tests were conducted at a constant spark timing and a constant lambda value of 1. Of the terpenes tested in the compression ignition engine, geranial and farnesene were found to be the best performing single component fuels in terms of combustion and emissions. In blends with fossil diesel, the presence of geranial or farnesene did not have a significant effect on combustion phasing up to a terpene content of 20% (wt/wt), though levels of NOx and CO did increase. In the spark ignition engine experiments of terpene and fossil gasoline blends, citronellene and linalool were found to be soluble in fossil gasoline and combusted in a steady manner up to a terpene content of 45% and 65% (wt/wt) respectively. Of those terpenes with the most potential as either diesel or gasoline fuels, geraniol and geranial were found to be the most toxic to Synechocystis, with farnesene and linalool less toxic and citronellene having no detrimental effect. Addition of n-dodecane to the cultures was found to ameliorate the toxic effects of all five terpenes

A Comparison Between Inter-Asterisk eXchange Protocol and Jingle Protocol: Session Time

Over the last few years, many multimedia conferencing and Voice over Internet Protocol (VoIP) applications have been developed due to the use of signaling protocols in providing video, audio and text chatting services between at least two participants. This paper compares between two widely common signaling protocols: InterAsterisk eXchange Protocol (IAX) and the extension of the eXtensible Messaging and Presence Protocol (Jingle) in terms of delay time during call setup, call teardown, and media sessions

Heteropolyacids in synthesis of benzoyl hydrazone derivatives

Keggin type of heteropolyacids as green reusable and efficient catalyst was used in the synthesis of benzoyl hydrazones from reaction of benzoic acid hydrazide and aldehyde and ketone derivatives. The synthesis of N-acetyl and N-benzoyl derivatives has also been performed by the reaction of obtained benzoyl hydrazones with acylcholorides in presence of this kind of heteropolyacids

Hernie Inguinoscrotale de l’Uretère: Fait Clinique et Revue de la Littérature

la hernie intrascrotale de l’uretère est une situation rare, nous rapportons un cas clinique, compliqué d’hydronéphrose gauche chez un patient de 83ans, l’anomalie avait été reconnue en peropératoire.Mots clés: Hernie, de l’uretère, le scrotum, hydronéphros