Performance improvement of an optical network providing services based on multicast

Operators of networks covering large areas are confronted with demands from some of their customers who are virtual service providers. These providers may call for the connectivity service which fulfils the specificity of their services, for instance a multicast transition with allocated bandwidth. On the other hand, network operators want to make profit by trading the connectivity service of requested quality to their customers and to limit their infrastructure investments (or do not invest anything at all). We focus on circuit switching optical networks and work on repetitive multicast demands whose source and destinations are {\em \`a priori} known by an operator. He may therefore have corresponding trees "ready to be allocated" and adapt his network infrastructure according to these recurrent transmissions. This adjustment consists in setting available branching routers in the selected nodes of a predefined tree. The branching nodes are opto-electronic nodes which are able to duplicate data and retransmit it in several directions. These nodes are, however, more expensive and more energy consuming than transparent ones. In this paper we are interested in the choice of nodes of a multicast tree where the limited number of branching routers should be located in order to minimize the amount of required bandwidth. After formally stating the problem we solve it by proposing a polynomial algorithm whose optimality we prove. We perform exhaustive computations to show an operator gain obtained by using our algorithm. These computations are made for different methods of the multicast tree construction. We conclude by giving dimensioning guidelines and outline our further work.Comment: 16 pages, 13 figures, extended version from Conference ISCIS 201

Mucosal Melanoma of the Head and Neck: A Retrospective Review and Current Opinion

Introduction: Head and Neck Mucosal Melanoma (HNMM) is an uncommon malignancy that arises in decreasing order in the nasal cavity, the paranasal sinuses, and the oral cavity. Although radical surgery followed by eventual radiotherapy is acknowledged as the mainstay treatment, patients with advanced stages or multi-focal tumors benefit from new systemic therapies. We wish to share our experience with these treatments and review the current literature. Materials and Methods: We present a case review of every patient treated in our center for an HNMM over the past 10 years, including every patient treated in our center for an HNMM over the past 10 years. We analyzed clinical characteristics, treatment modalities, and outcomes. Results: We included eight patients aged from 62 to 85 years old. We found six MM in the nasal cavity, one in the sphenoidal sinus, and one in the piriform sinus. Six patients underwent endoscopic surgery with negative margins, six underwent radiotherapy with variable modalities. Immunotherapy or targeted therapy was given in cases extensive tumors without the possibility of a surgical treatment or in two patient as an adjuvant treatment after R0 surgery. The three-year overall survival was 50%, and three patients (37.5%) are in remission. Conclusions: HNMM is associated with poor oncologic outcomes regarding the concerned patients of our review, as reported in the literature. New treatments such as immunotherapies or targeted therapies have not significantly changed the prognosis, but they may offer new interesting perspectives. Our small series of cases seems to confirm that surgical resection with negative margins improves overall survival

Experimental comparison of photon versus particle computed tomography to predict tissue relative stopping powers

Purpose: Measurements comparing relative stopping power (RSP) accuracy of state-of-the-art systems representing single-energy and dual-energy computed tomography (SECT/DECT) with proton CT (pCT) and helium CT (HeCT) in biological tissue samples. Methods: We used 16 porcine and bovine samples of various tissue types and water, covering an RSP range from 0.90urn:x-wiley:00942405:media:mp15283:mp15283-math-00010.06 to 1.78 urn:x-wiley:00942405:media:mp15283:mp15283-math-00020.05. Samples were packed and sealed into 3D-printed cylinders (urn:x-wiley:00942405:media:mp15283:mp15283-math-0003 cm, urn:x-wiley:00942405:media:mp15283:mp15283-math-0004 cm) and inserted into an in-house designed cylindrical polymethyl methacrylate (PMMA) phantom (urn:x-wiley:00942405:media:mp15283:mp15283-math-0005 cm, urn:x-wiley:00942405:media:mp15283:mp15283-math-0006 cm). We scanned the phantom in a commercial SECT and DECT (120 kV; 100 and 140 kV/Sn (tin-filtered)); and acquired pCT and HeCT (urn:x-wiley:00942405:media:mp15283:mp15283-math-0007 MeV/u, 2urn:x-wiley:00942405:media:mp15283:mp15283-math-0008 steps, urn:x-wiley:00942405:media:mp15283:mp15283-math-0009 (p)/urn:x-wiley:00942405:media:mp15283:mp15283-math-0010 (He) particles/projection) with a particle imaging prototype. RSP maps were calculated from SECT/DECT using stoichiometric methods and from pCT/HeCT using the DROP-TVS algorithm. We estimated the average RSP of each tissue per modality in cylindrical volumes of interest and compared it to ground truth RSP taken from peak-detection measurements. Results: Throughout all samples, we observe the following root-mean-squared RSP prediction errors urn:x-wiley:00942405:media:mp15283:mp15283-math-0011 combined uncertainty from reference measurement and imaging: SECT 3.10urn:x-wiley:00942405:media:mp15283:mp15283-math-00122.88%, DECT 0.75urn:x-wiley:00942405:media:mp15283:mp15283-math-00132.80%, pCT 1.19urn:x-wiley:00942405:media:mp15283:mp15283-math-0014 2.81%, and HeCT 0.78urn:x-wiley:00942405:media:mp15283:mp15283-math-00152.81%. The largest mean errors urn:x-wiley:00942405:media:mp15283:mp15283-math-0016 combined uncertainty per modality are SECT 8.22 urn:x-wiley:00942405:media:mp15283:mp15283-math-00172.79% in cortical bone, DECT 1.74urn:x-wiley:00942405:media:mp15283:mp15283-math-00182.00% in back fat, pCT 1.80 urn:x-wiley:00942405:media:mp15283:mp15283-math-00194.27% in bone marrow, and HeCT 1.37urn:x-wiley:00942405:media:mp15283:mp15283-math-00204.25% in bone marrow. Ring artifacts were observed in both pCT and HeCT reconstructions, imposing a systematic shift to predicted RSPs. Conclusion: Comparing state-of-the-art SECT/DECT technology and a pCT/HeCT prototype, DECT provided the most accurate RSP prediction, closely followed by particle imaging. The novel modalities pCT and HeCT have the potential to further improve on RSP accuracies with work focusing on the origin and correction of ring artifacts. Future work will study accuracy of proton treatment plans using RSP maps from investigated imaging modalities

A capacitated multi-vehicle covering tour problem on a road network and its application to waste collection

ABSTRACT: In most Swiss municipalities, a curbside system consisting of heavy trucks stopping at almost each household is used for non-recoverable waste collection. Due to the many stops of the trucks, this strategy causes high fuel consumption, emissions and noise. These effects can be alleviated by reducing the number of stops performed by the collection vehicles. One possibility consists of selecting a subset of candidate locations that are scattered throughout the municipality to place collection points which are used by residents to bring their waste. Provided that the underlying road network is available and that the collection vehicle has a known capacity, we refer to this problem as the capacitated multi-vehicle covering tour problem on a road network (Cm-CTP-R). We propose a road-network-based mixed-integer linear programming (MILP) formulation that exploits the sparsity of the network. We compare it against the MILP formulation that results from assuming a customer-based graph, which is typically used in vehicle routing problems (VRP). To solve large instances, we develop a two-phased heuristic approach that addresses the two subproblems the Cm-CTP-R is built on: a set covering problem to select the locations and a split-delivery VRP to determine the tours. Computational experiments on instances derived from real-life data show that the road-network-based formulation is better suited. Furthermore, the proposed heuristic provides good solutions with optimality gaps below 1.7% and finds better solutions for most of the instances that the exact method is not able to solve within a given time limit

CERTIFICATION REPORT Certified reference materials for testing of the presence/absence of Staphylococcus aureus enterotoxin A (SEA) in cheese: IRMM-359a-c

This report describes the preparation of three cheese powder matrix reference materials (IRMM-359a-c) and their certification for testing of the presence/absence of Staphylococcus aureus enterotoxin A (SEA). Raw milk cheese was decrusted, cut into cubes, chopped in a kitchen-type food processor for a short time, freeze-dried, cryogenically milled, and mixed (blank material IRMM-359a). Moreover, a second portion of raw milk cheese was decrusted and cut into cubes. After addition of water and spiking with a solution of SEA, the sample was homogenised using a high-speed grinder (Ultra-Turrax). The cheese slurry was freeze-dried, cryogenically milled and mixed with blank cheese powder to obtain the two SEA-containing materials at SEA target levels of 0.1 and 0.25 ng/g cheese, respectively (IRMM-359b, IRMM-359c). Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The minimum sample intake is 15.1 g cheese powder (representing 25 g of cheese after reconstitution) per replicate analysis (n=5), as stipulated in Commission Regulation 1441/2007, and therefore no dedicated study on the minimum sample intake was performed. The reference material was characterised in an interlaboratory comparison of laboratories of demonstrated competence and adhering to ISO/IEC 17025 and using the European Screening Method with the VIDAS SET2 and the Ridascreen SET Total for detection (further on named ESM/VIDAS and ESM/Ridascreen, respectively) [4]. Technically invalid results were removed, but no outlier was eliminated on statistical grounds only. Certified values are reported as probability of detection and expressed as either diagnostic specificity (ratio of true negatives divided by the sum of true negatives and false positives) for the blank material, or diagnostic sensitivity (ration of true positives divided by the sum of true positives and false negatives) for the SEA-containing materials. Uncertainties for homogeneity and stability were estimated, but not used for an uncertainty budget due to the nature of the certified values (presence/absence certification). Instead, the certified values are expressed as intervals with a 95% level of confidence. The preparation and processing of the material, homogeneity and stability studies, and the characterisation are described hereafter and the results are discussed.JRC.D.2-Standards for Innovation and sustainable Developmen

A likelihood-based particle imaging filter using prior information

Background: Particle imaging can increase precision in proton and ion therapy. Interactions with nuclei in the imaged object increase image noise and reduce image quality, especially for multinucleon ions that can fragment, such as helium. Purpose: This work proposes a particle imaging filter, referred to as the Prior Filter, based on using prior information in the form of an estimated relative stopping power (RSP) map and the principles of electromagnetic interaction, to identify particles that have undergone nuclear interaction. The particles identified as having undergone nuclear interactions are then excluded from the image reconstruction, reducing the image noise. Methods: The Prior Filter uses Fermi–Eyges scattering and Tschalär straggling theories to determine the likelihood that a particle only interacts electromagnetically. A threshold is then set to reject those particles with a low likelihood. The filter was evaluated and compared with a filter that estimates this likelihood based on the measured distribution of energy and scattering angle within pixels, commonly implemented as the 3σ filter. Reconstructed radiographs from simulated data of a 20-cm water cylinder and an anthropomorphic chest phantom were generated with both protons and helium ions to assess the effect of the filters on noise reduction. The simulation also allowed assessment of secondary particle removal through the particle histories. Experimental data were acquired of the Catphan CTP 404 Sensitometry phantom using the U.S. proton CT (pCT) collaboration prototype scanner. The proton and helium images were filtered with both the prior filtering method and a state-of-the-art method including an implementation of the 3σ filter. For both cases, a dE-E telescope filter, designed for this type of detector, was also applied. Results: The proton radiographs showed a small reduction in noise (1 mm of water-equivalent thickness [WET]) but a larger reduction in helium radiographs (up to 5–6 mm of WET) due to better secondary filtering. The proton and helium CT images reflected this, with similar noise at the center of the phantom (0.02 RSP) for the proton images and an RSP noise of 0.03 for the proposed filter and 0.06 for the 3σ filter in the helium images. Images reconstructed from data with a dose reduction, up to a factor of 9, maintained a lower noise level using the Prior Filter over the state-of-the-art filtering method. Conclusions: The proposed filter results in images with equal or reduced noise compared to those that have undergone a filtering method typical of current particle imaging studies. This work also demonstrates that the proposed filter maintains better performance against the state of the art with up to a nine-fold dose reduction

Twin study reveals non-heritable immune perturbations in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system underpinned by partially understood genetic risk factors and environmental triggers and their undefined interactions$^{1,2}$. Here we investigated the peripheral immune signatures of 61 monozygotic twin pairs discordant for MS to dissect the influence of genetic predisposition and environmental factors. Using complementary multimodal high-throughput and high-dimensional single-cell technologies in conjunction with data-driven computational tools, we identified an inflammatory shift in a monocyte cluster of twins with MS, coupled with the emergence of a population of IL-2 hyper-responsive transitional naive helper T cells as MS-related immune alterations. By integrating data on the immune profiles of healthy monozygotic and dizygotic twin pairs, we estimated the variance in CD25 expression by helper T cells displaying a naive phenotype to be largely driven by genetic and shared early environmental influences. Nonetheless, the expanding helper T cells of twins with MS, which were also elevated in non-twin patients with MS, emerged independent of the individual genetic makeup. These cells expressed central nervous system-homing receptors, exhibited a dysregulated CD25–IL-2 axis, and their proliferative capacity positively correlated with MS severity. Together, our matched-pair analysis of the extended twin approach allowed us to discern genetically and environmentally determined features of an MS-associated immune signature

Silicon based micro-optical collimating element for mid-infrared Quantum Cascade Lasers

A realization of a high numeric aperture, aspheric, silicon based collimating element for the mid-infrared (4 – 14 microns) Quantum Cascade Lasers, suited for mass production using computer driven reactive ion etching is presented

High numerical aperture silicon collimating lens for mid-infrared quantum cascade lasers manufactured using wafer-level techniques

We present an aspheric collimating lens for mid-infrared (4-14 µ) quantum cascade lasers. The lenses were etched into silicon by an inductively coupled plasma reactive ion etching system on wafer level. The high refractive index of silicon reduces the height of the lens prole resulting in a simple element working at high numerical aperture (up to 0.82). Wafer level processes enable the fabrication of about 5000 lenses in parallel. Such cost-eective collimating lens is a step towards the adoption of quantum cascade lasers for all its potential applications