Buffering-deflection tradeoffs in optical burst switching

A very important issue in optical burst switching (OBS) networks is the excessive burst drop when no suitable network resources are found during path reservation. In this study, a network scenario is evaluated in which AWG-based optical nodes are used as burst router nodes within the optical network. The two classical solutions to solve the burst contentions on the channels outgoing from the node are considered, that is, either based on buffering within the node, or by exploiting deflection routing. A performance evaluation is carried out to evaluate and compare these solutions for different network topologies with different node and traffic parameters. Our main contribution is to set numerical tradeoffs between burst deflection through the network and buffering in the node, so that a guidance in optical network design is provided where node buffering is inherently technologically limited.     

Electrochemically Induced Addition Reactions in the Absence of Solvent and Supporting Electrolyte

Solvent‐ and supporting electrolyte‐free electrolysis in a two‐compartment cell proved to be effective for the direct electroactivation of C H acid‐containing compounds vs. catalytic addition processes. Michael adducts (including quaternary carbon centres) and 2‐nitroalkanols were obtained in very good yields and selectivity on application of a catalytic amount of electricity under galvanostatic conditions.     

Regulatory Noncoding and Predicted Pathogenic Coding Variants of CCR5 Predispose to Severe COVID-19

Genome-wide association studies (GWAS) found locus 3p21.31 associated with severe COVID-19. CCR5 resides at the same locus and, given its known biological role in other infection diseases, we investigated if common noncoding and rare coding variants, affecting CCR5, can predispose to severe COVID-19. We combined single nucleotide polymorphisms (SNPs) that met the suggestive significance level (P ≤ 1 × 10⁻⁵) at the 3p21.31 locus in public GWAS datasets (6406 COVID-19 hospitalized patients and 902,088 controls) with gene expression data from 208 lung tissues, Hi-C, and Chip-seq data. Through whole exome sequencing (WES), we explored rare coding variants in 147 severe COVID-19 patients. We identified three SNPs (rs9845542, rs12639314, and rs35951367) associated with severe COVID-19 whose risk alleles correlated with low CCR5 expression in lung tissues. The rs35951367 resided in a CTFC binding site that interacts with CCR5 gene in lung tissues and was confirmed to be associated with severe COVID-19 in two independent datasets. We also identified a rare coding variant (rs34418657) associated with the risk of developing severe COVID-19. Our results suggest a biological role of CCR5 in the progression of COVID-19 as common and rare genetic variants can increase the risk of developing severe COVID-19 by affecting the functions of CCR5.     

High‐performance execution of service compositions: a multicore‐aware engine design

Although modern computer hardware offers an increasing number of processing elements organized in nonuniform memory access (NUMA) architectures, prevailing middleware engines for executing business processes, workflows, and Web service compositions have not been optimized for properly exploiting the abundant processing resources of such machines. Amongst others, factors limiting performance are inefficient thread scheduling by the operating system, which can result in suboptimal use of system memory and CPU caches, and sequential code sections that cannot take advantage of multiple available cores. In this article, we study the performance of the JOpera process execution engine on recent multicore machines. We first evaluate its performance without any dedicated optimization for multicore hardware, showing that additional cores do not significantly improve performance, although the engine has a multithreaded design. Therefore, we apply optimizations on the basis of replication together with an improved, hardware‐aware usage of the underlying resources such as NUMA nodes and CPU caches. Thanks to our optimizations, we achieve speedups from a factor of 2 up to a factor of 20 (depending on the target machine) when compared with a baseline execution ‘as is’. Copyright © 2012 John Wiley & Sons, Ltd.     

Multiobjective robust design using physical programming

This paper develops a flexible Physical Programming (PP) based Robust Design Optimization (RDO) method. RDO yields a system that performs with minimal variability in the face of input variations or uncertainties. RDO methods generally seek to minimize the variation of an Aggregate Objective Function (AOF), thereby also minimizing the effect of input variations on the physical system - it is hoped. RDO seeks to maintain design feasibility under input variations. The optimization outcome depends on (i) the acceptable level of variation in performance, and (ii) the level of input variations. For RDO to be flexible, it is desirable to allow designers to express preference with respect to specific design metric values, and variation levels thereof. Similarly, RDO would ideally allow the designer either to prescribe parameter tolerance levels, or to maximize their allowable levels to minimize manufacturing cost. This paper's approach possesses the above desirable features, and provides numerical examples. This paper also discusses the benefits of formulating RDO in terms of physically meaningful design performance degradation levels, rather than in terms of the variation of an AOF.     

Feasibility of Rigidified Inflatable Structures for Housing

Rigidified inflatable structures (RIS) are thin, flexible membrane structures that are pneumatically deployed. After deployment, these structures harden because of chemical or physical change of the membrane. Because of this change, or rigidification, these structures no longer require pneumatic pressure to maintain their shape. With the aim of reducing the cost and examining the feasibility of RIS structures, a new material is proposed, developed, and evaluated. This material involves the formation of a semi-interpenetrating polymer network based on polyvinyl chloride and an acrylate-based reactive plasticizer. The economical and environmental performances of RIS using this new material are assessed by means of a case study. In this study, the performance of RIS technology is compared with that of a typical wood light-frame structure in the application of a small single-family house. The study indicates that the cost of ownership in present day value for the RIS is approximately 35% less than the cost of a comparable wood light-frame structure. The study also indicates that significant environmental benefits exist with the use of RIS. These structures use significantly less in terms of resources than do wood frame structures: approximately 2 times less in materials originating from nonrenewable fossil resources, approximately 2 times less in material originating from trees, and approximately 19 times less in materials originating from inorganic resources. The study concludes by delineating various means available to further increase the economical and environmental performance of RIS technology.     

Direct-EI in LC-MS: towards a universal detector for small-molecule applications

This review article will give an up-to-date and exhaustive overview on the efficient use of electron ionization (EI) to couple liquid chromatography and mass spectrometry (LC-MS) with an innovative interface called Direct-EI. EI is based on the gas-phase ionization of the analytes, and it is suitable for many applications in a wide range of LC-amenable compounds. In addition, thanks to its operating principles, it prevents unwelcome matrix effects (ME). In fact, although atmospheric pressure ionization (API) methodologies have boosted the use of LC-MS, the related analytical methods are sometime affected by inaccurate quantitative results, due to unavoidable and unpredictable ME. In addition, API's soft ionization spectra always demand for costly and complex tandem mass spectrometry (MS/MS) instruments, which are essential to acquire an "information-rich" spectrum and to obtain accurate quantitative information. In EI a one-stage analyzer is sufficient for a qualitative investigation and MS/MS detection is only used to improve sensitivity and to cut chemical noise. The technology illustrated here provides a robust and straightforward access to classical, well-characterized EI data for a variety of LC applications, and readily interpretable spectra for a wide range of areas of research. The Direct-EI interface can represent the basis for a forthcoming universal LC-MS detector for small molecules.     

Multi-wavelength switching in IP optical nodes adopting different buffering strategies

The paper addresses the topic of long-haul optical networking for the provision of large-bandwidth IP services. A class of optical packet switching architectures is considered which adopts an arrayed wavelength grating device as packet router. The architecture performs slotted packet switching operations and fully exploits the wavelength routing capabilities by allowing multi-wavelength switching. Fiber delay lines are used to perform optical packet buffering, which accomplishes either input queueing or shared queueing. Here a thorough performance evaluation is carried out with different buffering configurations and the effect of various switch parameters on traffic performance is studied.     

Effect of free radicals generating compounds towards the flammability of w-phosphonated polystyrenes — V

Summary Effect of some free-radicals generating compounds, such as organic peroxides, hydroperoxides and polysulfides, on the Oxygen Index of end phosphonated polystyrenes is investigated. It is shown that some combinations of end phosphonated polystyrene with free-radicals initiators, may be said to have a synergestic effect on flame-retardant properties of standard polystyrene.     

When is a request for assisted suicide legitimate? Factors influencing public attitudes toward euthanasia.

A mail survey of 810 Vancouver area residents investigated how the public's acceptance of a request for euthanasia was influenced by the method of death (e.g., lethal injection vs withdrawal of life-support) and by the identity of the patient featured in a vignette (e.g., stranger vs oneself). The study also identified considerations people found most important in deciding whether a patient's request for euthanasia was legitimate (e.g., patient's pain, chance for recovery). Life-support withdrawal was found significantly more acceptable (90% support) than a lethal injection (79% support), yet the identity of the person involved did not affect the acceptability of euthanasia. However, a factor analysis suggested that the decisions about oneself may be more complex and more closely scrutinized than decisions about others. The considerations rated most important by participants paralleled legal guidelines from the Netherlands and Oregon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)